CLIMATE SYSTEM
The invention relates to a climate system comprising at least one latent heat storage heat exchanger assembly, said latent heat storage heat exchanger assembly comprising: —a channel part having an inlet end with a flow cross sectional A1, an outlet end a flow cross sectional area A2, and said inlet end defining an incoming air direction; —at least one latent heat storage heat exchanger comprising a plurality of plate shaped PCM units that comprise a container holding PCM, said PCM units positioned parallel at a spacing d behind one another; —a frame unit providing a support plane for holding said at least one latent heat storage heat ex changer in said channel part, said frame unit mounted with said support plane at an angle β between 5 and 45 degrees with respect to the incoming air direction.
The invention relates to climate system. The invention relates to a climate unit for such a climate system. The invention further relates to a latent heat storage heat exchanger assembly for use in a climate system. The invention relates to a latent heat storage heat exchanger for use in a climate system.
BACKGROUND OF THE INVENTIONClimate systems for buildings are generally known. Some of said climate control systems use a phase change material to provide latent heat storage. WO2003102484A2 discloses a climate control unit located in the vicinity of the ceiling. The climate control unit comprises plate shaped latent heat accumulator bodies. The plate shaped bodies are parallel positioned at a predetermined distance with respect to each other to form an air channel between adjacent plate shaped bodies. The plate shaped bodies comprise a cavity filled with a phase change material. A phase change material (PCM) is a substance with a high latent heat of fusion which, melting and solidifying at a certain temperature, is capable of storing and releasing large amounts of energy. Heat is absorbed or released when the material changes from solid to liquid and vice versa. Bodies filled with PCMs are classified as latent heat storage (LHS) units or PCM units.
The plate shaped bodies have to be manufactured separately. Subsequently, the plate shaped bodies are positioned parallel in the climate control unit. The plate shaped bodies together form a latent heat storage heat exchanger. Such a latent heat storage heat exchanger comprises a plurality of plate shaped elements. The plate shaped elements are parallel positioned at a predetermined distance with respect to each other to form an air channel between adjacent plate shaped elements. Each element comprises a cavity filled with a phase change material. The number of individual plate shaped elements mainly defines the costs of a climate control unit. Consequently, relative large plate shaped elements are used in climate control units instead of smaller ones. Known plate-shaped elements are from aluminium, are filled with micro-encapsulated PCM, and/or have foam or other inserts that reduce the PCM contents per volume of element.
In “nieuwe generatie autarkische datahotels”, RCC Total Energy, No 5 december 2009, Harry Schmitz, a data hotel is disclosed in which single containers are provided with parts of a data hotel and with a complete climate control for that part of the data hotel.
SUMMARY OF THE INVENTIONThe object of the invention is to provide a climate unit for use in a climate control system which allows to realize at least one of: reduction of manufacturing costs of climate control system, increased latent heat storage capacity in Wh/kg or Wh/L, increased heat transfer characteristics compared with the known embodiment of a climate control system provided with parallel and horizontal positioned plate shaped latent heat storage bodies. Another or alternative object of the invention is to provide a building with climate control that is cheap, scalable, easy to install.
The invention pertains to a climate system comprising at least one latent heat storage heat exchanger assembly, said latent heat storage heat exchanger assembly comprising:
a channel part having an inlet end with a flow cross sectional A1, an outlet end a flow cross sectional area A2, and said inlet end defining an incoming air direction;
at least one latent heat storage heat exchanger comprising a plurality of plate shaped PCM units that comprise a container holding PCM, said PCM units positioned parallel at a spacing d behind one another;
a frame unit providing a support plane for holding said at least one latent heat storage heat exchanger in said channel part, said frame unit mounted with said support plane at an angle β between 5 and 45 degrees with respect to the incoming air direction.
The setting of the latent heat storage heat exchanger allows a climate system with efficient heat transfer using a minimal amount of energy. Furthermore, construction is simple.
In case of a rectangular channel part, the angle β evidently is the angle between the bottom of the channel and the support plane. In most common cases, the incoming air direction is the (mathematical) normal to the inlet flow-through area.
The climate system, in particular the latent heat storage heat exchanger assembly, can be designed in such a way that the flow-though cross sectional area from inlet end to outlet end does not become smaller. The angle β can be set, depending on spacing d and the thickness of the PCM units, for instance, in such a way that the flow through cross sectional area remains almost the same for air passing the assembly. Furthermore, a modular design can be produced.
In an embodiment, said latent heat storage heat exchanger assembly comprising a support frame providing mutually parallel, opposite upper and lower support surfaces, and said frame unit for holding a latent heat storage heat exchanger between said support surfaces, said frame unit mounted at an angle β with respect to the lower support surface.
In an embodiment, said frame is provided for holding the plate shaped elements perpendicular to the support plane or support surfaces.
The invention further pertains to a latent heat storage heat exchanger assembly comprising a support frame providing mutually parallel upper and lower support surfaces, and a frame unit for holding a latent heat storage heat exchanger between said support surfaces, said frame unit mounted at an angle with respect to the lower support surface, each latent heat storage heat exchanger comprises a plurality of plate shaped elements at predetermined mutual distances of each other and the plate shaped elements provided perpendicular to the support surfaces.
In an embodiment, the frame unit provides a support plane for said latent heat storage heat exchanger at said angle, in an embodiment said support plane angle is at 5-45 degrees, in an embodiment at 10-30 degrees. Thus, the latent heat storage heat exchangers can are installed in the assembly that a fluid flow flows along the plate shaped elements in an optimal way for exchanging heat with PCM.
In an embodiment, the support frame comprises a block-shaped part, in an embodiment formed by plate and/or profile elements, housing said frame unit. For instance, using metal of polymer plates and/or profiles, a rectangular channel part can be provided. In an embodiment, it has rectangular fluid openings forming two opposite planes of the block-shaped support frame. In an embodiment, four rectangular closes walls define four sides of a (mathematical) block and the fluid openings form two opposite remaining sides of said (mathematical) block. This allows the assemblies to be used an easy to combine modules.
In an embodiment, the support frame comprises plate walls forming a rectangular channel part, in an embodiment said frame unit is attached in and onto the support frame.
In an embodiment, the plate shaped elements of the latent heat storage heat exchangers are provided mutually parallel and said latent heat storage heat exchanger has a longitudinal axis through said plate shaped elements, in an embodiment parallel to said upper and lower support surfaces.
In an embodiment, the heat storage heat exchanger assembly further comprises a fluid flow path between said upper end lower support planes, through said latent heat storage heat exchanger crossing said support plane, where defined.
In an embodiment, the heat storage heat exchanger assembly has fluid openings for allowing a fluid flow into and out of said assembly and past said latent heat storage heat exchanger, and an assembly longitudinal axis between said upper and lower support plates and connecting said openings. Said assembly longitudinal axis is perpendicular to said latent heat storage heat exchanger longitudinal axis. In an embodiment said latent heat storage heat exchanger assembly comprises at least two latent heat storage heat exchangers. In an embodiment in said assemblies arranged with their longitudinal axes parallel. Thus, the assembly allows easy combination of standardized latent heat storage heat exchangers in a further standardized assembly.
In an embodiment, the heat storage heat exchanger assembly further comprises a front plate provided to the most upstream latent heat storage heat exchanger for controlling, in an embodiment blocking, fluid flows to flow in between the plate elements coming from the upstream face of the most upstream latent heat storage heat exchanger.
In an embodiment, the heat storage heat exchanger further comprises a rear plate provided to the most downstream latent heat storage heat exchanger for controlling, in an embodiment blocking fluid flows to flow out between the plate elements past the downstream face of the most downstream latent heat storage heat exchanger.
According to an aspect of the invention, the object is alternatively achieved by a latent heat storage heat exchanger assembly comprising a frame with a plurality of rectangular frame units, wherein adjacent frame units are hingingly coupled to one another along a coupling end, wherein each frame unit comprises a latent heat storage heat exchanger, wherein each latent heat storage heat exchanger comprises a plurality of plate shaped elements at predetermined mutual distances of each other, and wherein the plate shaped elements are configured perpendicular to the coupling end.
The latent heat storage heat exchanger can be constructed and installed easily.
In case of defects, some of the latent heat storage heat exchangers can be replaced.
In an embodiment, the container has a length of between 40 and 100 cm. In an embodiment, the container has a width of between 15 and 30 cm. In an embodiment, the container has a thickness of 0.5-2 cm. In an embodiment, the container has a wall thickness of between 0.5 and 3 mm. In particular said container when filled with PCM provides a PCM layer with a thickness of between 0.5 and 1.5 cm.
In an embodiment, the container is produced as one part. In an embodiment, this means that it is produced from one piece of material.
The container of the invention may be produced using for instance a 3D printing process, or an additive manufacturing process. Other shaping methods may be used that produce the container from a plastic or polymer material in one piece. In an embodiment, the container is produced in a blow-moulded process. Blow moulding is a production process that allows serial production at low costs and sure, in particular providing a leak-tight container. Many processes in the art require welds or other seams for adding various pieces together, in particular to form a single cavity which comprise a series of compartments that are in fluid communication.
In an embodiment, the container is made from a thermoplastic material.
The invention further provides a PCM unit comprising the container described above and filled with PCM. In an embodiment, said PCM substantially consisting of an aqueous solution of a salt hydrate.
In literature, the label “PCM” is used for many types of material. In particular, in an embodiment of the invention, it is a substance with a high heat of fusion which, melting and solidifying at a certain temperature, is capable of storing and releasing large amounts of energy. Heat is absorbed or released when the material changes from solid to liquid and vice versa; thus, PCM is also classified as latent heat storage (LHS) material. when PCMs reach the temperature at which they change phase (their melting temperature) they absorb large amounts of heat at an almost constant temperature. The PCM continues to absorb heat without a significant rise in temperature until all the material is transformed to the liquid phase. When the ambient temperature around a liquid material falls, the PCM solidifies, releasing its stored latent heat. Within the human comfort range of 18° to 30° C., some PCMs are very effective. They store 5 to 14 times more heat per unit volume than conventional storage materials such as water, masonry or rock.
In general, there exist organic and inorganic PMC. PCM can for instance be based upon water with paraffin or fatty acids. In an embodiment, the phase change material is selected from the group consisting of paraffin, thermoplastic polymers, organic acids, aqueous solutions of salts, chlathrate hydrates, salt hydrates, mixtures of salt hydrates, salts and eutectic blends of salts and alkali metal hydroxides.
In the current invention, particularly suited is PCM based upon salt hydrates. The general formula for these salt hydrates is M.nH2O. In particular, in the current invention, CaCl2.6H2O can be used. This material in general has a melting temperature of about 28° C. Using additives, this temperature can be set between about 15-35° C. In use in buildings for climate systems, in general PCM is used which has a melting temperature of between 18 and 26° C. For conditioning zones in a building at a temperature that is comfortable for human beings, NEN 15251 for instance defines a temperature of 19° C. if the outdoor temperature is below 0° C., up to a maximum of 27° C. if it is tropically warm outside.
According to an aspect of the invention, this object is achieved by a climate system comprising at least two climate units, said climate units for coupling to a building for climate control of air in said building, and comprising a rectangular box-shaped mobile housing having housing walls and which housing is stackable onto similar climate units, wherein said housing comprises:
a heat exchanger comprising PCM material inside said housing;
a ventilation air channel in said rectangular box-shaped mobile housing and including said heat exchanger, said ventilation air channel for passing ventilation air from a ventilation inlet of said rectangular box-shaped mobile housing via and through said heat exchanger out to a ventilation outlet of said rectangular box-shaped mobile housing;
a return air channel through said rectangular box-shaped mobile housing for transporting return air from a return air inlet of said rectangular box-shaped mobile housing to an exhaust air outlet of said rectangular box-shaped mobile housing;
a ventilation air channel coupling channel part in fluid communication with said ventilation air channel, connecting opposite housing walls, and having opposite coupling passages in said opposite housing walls for allowing coupling of ventilation air channels of further, similar climate units, and
a return air channel coupling channel part in fluid communication with said return channel, connecting opposite housing walls, and having opposite coupling passages in said opposite housing walls for allowing coupling to return air channels of other, similar climate units, and wherein said climate units are positioned with said ventilation air channel coupling channels parts in fluid communication and with their return air channel coupling channel part in fluid communication.
Thus, a climate system can be provided that are easy and fast to build. The climate system can be cheap. Furthermore, latent heat storage heat exchange assemblies allow a further modular system for making a climate control unit that can be designed to meet any need. Using the modular design, it is possible for instance to renovate existing buildings, or stepwise reduce the installed heating or cooling power. The modular units furthermore can be produced at one location, ant easily transported to a site of use. In particular when the housing is based upon a sae container, for instance a 20 Ft or 40 Ft container.
The climate control system that can be build using the climate units of the current invention is in particular useful in situation where in a building an access of heat is produced that needs to be removes. An example of such a building is d building housing a lot of running, electronic equipment. An example of such a building is a data hotel, a server park, or similar buildings.
In the climate control units, the return air channel as such does not pass air through the heat exchanger with PCM (Phase Change Material). The return air channel runs past the heat exchanger provided with PCM.
In the current application, when using for instance the terms “parallel”, “rectangular”, “perpendicular”, it should be evident that small deviations from the absolute mathematical definitions can be possible. In fact, a deviation of the absolute mathematical definition can be possible as long as the parts are allowed to fulfil their functional role. In some of the current designs, a deviation of as much as 10% is possible. In most of the current designs a deviation of 1-5% can be possible.
Here, the feature “air channel” is a conduit of air. It can be a standard air conduit used in air conditioning systems. Alternatively, as also shown in the description of embodiments, it can be a channel bounded by walls of a housing and walls provided in that housing.
The housing is a mobile housing. Such a housing usually is free standing and has surrounding walls. Often, these walls are closed walls. In the current invention, these walls will often be (heat) insulated. In an embodiment, the housing is a sea container, commonly available in the sizes 20 Ft and 40 Ft.
The heat exchanger comprising PCM material can be a general heat exchanger allowing ventilation air to exchange heat with PCM material in order to heat or cool the ventilation air using the stored latent heat of the PCM material. Often, the PCM is provided in plate-shaped containers. These containers can be stacked or positioned with respect to one another to allow air to flow passed and around such PCM units. As also described in NL of the current applicant, the PCM units can easily be build together to form PCM latent heat storage heat exchangers. In the description, PCM latent heat storage heat exchangers are presented that provide a modular and simple way of building PCM assemblies, in this description referred to as latent heat storage heat exchange assemblies. These assemblies can be build together in PCM stacks, in this description also referred to as latent heat storage heat exchange stacks. These stacks can be build in into the climate unit of the current invention to provide modular, scalable climate systems.
In an embodiment, the respective passages of the coupling channel parts for the inlet for ventilation air and the outlet for return air.
In an embodiment of the climate system, said return air channel coupling part and ventilation air coupling part are positioned with a coupling passage in the same housing wall to allow coupling of said ventilation air channel and said return air channel to one and the same similar climate unit. allows it to select any number of climate units.
In an embodiment, part of said ventilation air channel is formed by opposite housing wall parts, at least part of that ventilation air channel part forming said coupling channel part.
In an embodiment, in operation said ventilation air channel has a flow direction from an upstream end of said ventilation air channel at said ventilation inlet to a downstream end of said ventilation air channel at said ventilation outlet, and said opposite housing wall parts are side walls of said ventilation air channel. In this way, the channel is provided in an efficient way.
In an embodiment, upstream and downstream ends of said ventilation air channel are formed by opposite housing walls. In these walls, passages can be provided as inlet and outlet for ventilation air. The passages can be provided with closures that can be operated to open and close a passage, and thus act as a valve.
In an embodiment, said ventilation air channel coupling channel part is cross with respect to said ventilation air channel, in particular perpendicular with respect to said ventilation air channel, more in particular crossing said ventilation air channel perpendicular.
In an embodiment, part of said return air channel is formed by opposite housing wall parts, at least part of that return air channel part forming said coupling channel part. This allows an efficient building. The coupling channel part can for instance couple a top wall and a bottom wall of the housing, allowing climate units to be stacked on to of one another, allowing them to operate as a single unit. Alternatively, side walls can be coupled, allowing climate unites to be placed next to one another and to form functionally a single system. The coupling can be combined.
In an embodiment, in operation said return air channel has a flow direction from an upstream end of said return air channel at said return inlet to a downstream end of said return air channel at said return air outlet, and said opposite housing wall parts are side walls of said return air channel.
In an embodiment, upstream and downstream ends of said ventilation air channel are formed by opposite housing walls.
In an embodiment, said return air channel coupling channel part is cross with respect to said return air channel, in particular perpendicular with respect to said return air channel, more in particular crossing said return air channel perpendicular.
In an embodiment, said ventilation air channel coupling channel part is provided inside said housing at said ventilation air channel end, in particular near or at a ventilation air inlet end of said ventilation air channel. In an embodiment, said return air channel coupling channel part is provided inside said housing at said return air channel end.
In an embodiment, part of at least one of said coupling channel parts is formed by part of a further wall connecting both opposite walls, in particular said channel part is provided at a corner of said housing, in a further particular embodiment said channel part is delimited by walls including four wall parts of said housing.
In an embodiment, said further wall comprises a selectively operable passage for providing said ventilation outlet.
In an embodiment, said return air channel coupling channel part is provided inside said housing at a return air channel downstream end, in particular near or at a return air outlet end of said return air channel.
In an embodiment, part of said channel part is formed by part of a further wall connecting both opposite walls.
In an embodiment, said further wall comprises a selectively operable passage for providing said exhaust air outlet.
In an embodiment, said return air channel comprises a selectively operable passage near its downstream end, said passage coupling said return air channel and said ventilation air channel before said heat exchanger comprising said PCM, said passages when at least partially open providing a channel loop providing at least part of said return air into said ventilation air channel.
In an embodiment, said housing further comprises an air driving device in said ventilation channel and in said return air channel. For instance, ventilators are installed. Other devices may be possible. Providing the latent heat storage heat exchangers in said housing adds to the independent modularity and scalability of the device.
In an embodiment, the climate unit comprises a control device, in particular in said rectangular box-shaped mobile housing, and a temperature sensor in both said ventilation air channel and said return air channel and operationally coupled to said control device. The control device can be operated at modi that are for instance described in the discussion of the drawings.
In an embodiment, said control device is can be operationally coupled to similar control devices of similar climate units, forming a control system.
In an embodiment, said rectangular box is a rectangular parallelepid or rectangular cuboid, allowing easy stacking.
In an embodiment, said housing comprises at least one wall dividing said housing into said ventilation channel and said return air channel.
In an embodiment, said walls have wall parts that can selectively be opened and closed for providing valves in said channels.
In an embodiment, said housing is at least 10 m3, in an embodiment it is an at least 20 Ft sea container.
The invention further pertains to climate unit for coupling to a building for climate control of air in said building, and comprising a rectangular box-shaped mobile housing having housing walls and which housing is stackable onto similar climate units, wherein said housing comprises:
a heat exchanger comprising PCM material inside said housing;
a ventilation air channel in said rectangular box-shaped mobile housing and including said heat exchanger, said ventilation air channel for passing ventilation air from a ventilation inlet of said rectangular box-shaped mobile housing via and through said heat exchanger out to a ventilation outlet of said rectangular box-shaped mobile housing;
a return air channel through said rectangular box-shaped mobile housing for transporting return air from a return air inlet of said rectangular box-shaped mobile housing to an exhaust air outlet of said rectangular box-shaped mobile housing;
a ventilation air channel coupling channel part in fluid communication with said ventilation air channel, connecting opposite housing walls, and having opposite coupling passages in said opposite housing walls for allowing coupling of ventilation air channels of further, similar climate units, and
a return air channel coupling channel part in fluid communication with said return channel, connecting opposite housing walls, and having opposite coupling passages in said opposite housing walls for allowing coupling to return air channels of other, similar climate units.
According to a further aspect of the invention, the above-referred object is achieved by a latent heat storage heat exchanger for use in a climate control system, the latent heat storage heat exchanger comprises a plurality of plate shaped elements (for instance PCM units), wherein the plate shaped elements are parallel positioned at a predetermined distance with respect to each other to form a fluid channel between adjacent plate shaped elements and each element comprises a cavity filled with a phase change material. In an embodiment, the latent heat storage heat exchanger comprises a coupling structure configured to coupled the cavities of the plurality of plate shaped elements to form one coupled cavity filled with phase change material.
In fact, in an embodiment of the invention, the latent heat storage heat units can comprise one or more of the latent heat storage heat exchangers.
According to an aspect of the invention, the latent heat storage heat exchanger comprises a coupling structure configured to couple the cavities of the plurality of plate shaped elements to form one coupled cavity filled with phase change material.
The manufacturing costs of a climate control unit provided with a latent heat storage heat exchanger comprising a plurality of plate shaped elements comprising a PCM-material may be linear to the number of elements. Each of the plate shaped elements is obtained by the following process steps: manufacturing the body; filling the body with a PCM-material via an opening in the body; sealing the body. Subsequently, each element has to be positioned in the climate control unit. By manufacturing a body which comprises the coupling structure according to the invention, one latent heat storage heat exchanger is obtained having the features of a plurality of plate shaped elements when positioned in a climate control unit, but which could be obtained be much less processing steps, namely manufacturing the body with the coupling structure; filling the body, i.e. all plate shaped elements, in one run, and sealing the body. Subsequently only one body instead of a plurality of plate shaped elements has to be positioned in the climate control unit. In this way, the manufacturing costs of a climate control unit may be reduced. Furthermore, the coupling structure enables us to provide a latent heat storage heat exchanger provided with a multitude of smaller plate shaped elements without increasing the amount of processing steps and thus the manufacturing costs of a latent heat storage heat exchanger. Further, the coupling structure functions as a spacer to position the plate shaped elements parallel and at a predetermined distance to each other.
Hence, it is a further aspect of the invention to provide an alternative PCM unit and use thereof in a climate system, which preferably further at least partly obviates one or more of above-described drawbacks.
The PCM unit comprises a container which in an embodiment is produced using blow-moulding. In an embodiment, the container has the shape of a rectangular panel with a longitudinal axis, a front and back facing wall, end walls and longitudinal walls enclosing a container cavity. Said blow-moulded container further comprises a filling opening. Said container cavity is in an embodiment divided into a series of elongated compartments and comprising partitioning walls extending between said front and back facing wall. Alternatively, the PCM unit can have an other shape that comprise a front and back facing wall that is substantially parallel and a circumferential wall connecting those facing walls.
The container allows a PCM unit that is dimensionally stable. Furthermore, such a PCM unit can be used for a long period of time without degradation, even in stationary situations. The container is further cheap to produce. A blow-moulded container, for instance, provides a sure and leak-tight container for holding the PCM material. In other words, the container of the current description in their different embodiments provides one or more of the following enhancements. The embodiments provide more sure and leak-free panels as the amount of welds to obtain a sealed container can be reduced significantly. The panels have improved dimensional stability, making it possible to decrease a space between panels in a stack of PCM-panels. Furthermore, the construction of the container reduces a decrease of latent heat storage capacity in time when the container is filled with inorganic PCM.
The PCM units of the invention usually have a capacity of at least 9 kilogram PCM per square meter surface area.
In general, PCM can be provided in micro encapsulation. In micro encapsulation, in general, the PCM is provided in smaller agglomerates, for instance. PCM can also be provided via macro encapsulation. Both micro and macro encapsulation of CM can be done on most known types of PCM. For all combinations of the specific way of providing PCM and the PCM used there are disadvantages. It was found that using the invention, it was possible to increase universal application of PCM. In particular, it was found that macro encapsulation of PCM can be used in climate conditioning.
In this description, the phase change material or PCM is a material that in the container can be in a liquid form or in a solid form. In use, it changes its phase between liquid and solid, and in that way either takes up heat (by melting) or releases heat (by solidifying. In the container of the invention, the PCM as such is poured in the container in its liquid form.
In an embodiment, the container is filled with PCM material via said filling opening.
A series of the PCM units can be combined into various different types of PCM modules for used in different types of climate systems.
One important aspect of the PCM units is that it was found that extreme undercooling of inorganic PCM can be reduced so that the regeneration of the PCM units is much easier if the PCM units melt for less than 80%, in particular less than 85%. It was (also) found that for different applications, different thicknesses of the PCM layer in a unit were optimal.
For use in convection systems, it was found that in an embodiment the PCM unit has a thickness resulting in a PCM layer of less than 3 cm thick. In this respect, in particular the convection is forced convection by means of an air displacement unit like a ventilator, or internal induction. In an embodiment, the PCM layer has a thickness of 0.5-2 cm. In particular, the PCM layer in the PCM unit has a thickness of between 0.8 and 1.5 cm. It was found that in particular in forced convection units, when using laminar flow of air and a slit width of between 1 and 6 mm, this provides an optimal PCM thickness. If the temperature difference between the PCM and air flowing around the PCM unit is low, for instance like the temperature differences occurring in the Netherlands, the slit width or distance between PCM units is about 3-5 mm. If the temperature difference is larger, for instance in more tropical regions, the slit width or distance between PCM units is larger that that, about 4-7 mm. The slit widths allow an energy-efficient flow of air around the PCM units. Modification of a slit width allows optimal use of the PCM unit, in particular in view of its width.
In another embodiment, in particular in cases where free convection takes place or heat exchange takes place through radiation, the PCM unit has a thickness resulting in a PCM layer of less than 2 cm. In particular, the PCM layer is less than 1.5 cm. In an embodiment, the PCM layer in the PCM unit is between 0.3 and 1.5 cm. In particular for use in PCM modules for use in floors, a thickness at the lower side of the range is preferred. Thus, a PCM layer of between 0.5 and 1.3 cm provides good results: the PCM in the PCM units remain stable in time, i.e. retain their latent heat storage capacity, and the heat storage capacity is still large enough.
Further aspects of the invention are amongst others provided in the dependent claims.
In an embodiment, the coupling structure divides the fluid channel between adjacent plate shaped elements in two channel parts.
In an embodiment, the coupling structure divides the fluid channel between adjacent plate shaped elements symmetrically in two equal channel parts.
In an embodiment, the coupling structure forms a plate shaped cavity which is perpendicular to the plurality of plate shaped elements.
In an embodiment, the coupling structure has a length axis which is larger than a length axis of the plate shaped elements.
In an embodiment, the latent heat storage heat exchanger comprises a housing of one material to form the one coupled cavity.
In an embodiment, the housing comprises a bin part and a cover part, wherein the bin part forms essentially the one coupled cavity.
In an embodiment, the bin part and the cover part are injection moulded parts.
In an embodiment, the cover part comprises at least one opening for filling the one coupled cavity with the PCM material.
In an embodiment, the openings are configured for receiving a sealing member.
In an embodiment, the opening and sealing member are coupled by means of a screwed connection.
In an embodiment, housing is made from an injection-mouldable polymer material, in an embodiment a thermoplastic polymer material, in an embodiment from HDPE.
In an embodiment, the bin part and the cover part are coupled by means of one continuous circular weld.
In an embodiment of the invention, the coupling structure divides the fluid channel between adjacent plate shaped elements in two channel parts. In an advantageous embodiment, the coupling structure divides the fluid channel between adjacent plate shaped elements symmetrically in two equal channel parts. These features provide a robust structure, wherein the coupling structure extends along the complete length of the fluid channel between two adjacent plate shaped elements.
In an embodiment of the invention, the coupling structure forms a plate shaped cavity which is perpendicular to the plurality of plate shaped elements. This feature provides a structure which makes it easy to fill each of the plate shaped elements of the latent heat storage heat exchanger with a PCM-material.
In an embodiment of the invention, the coupling structure has a length axis which is larger than a length axis of the plate shaped elements. This feature provides a latent heat storage heat exchanger with relative small plate shaped elements. This allows us the provide a latent heat storage heat exchanger with improved characteristics without increasing the flow rate through the latent heat storage heat exchanger. An improved characteristic could be an increased latent heat storage capacity, an increase in the total surface of the plate shaped elements along the air channels, a reduced air resistance as the air channels can be shorter, or any other combination of improved characteristics.
In an embodiment of the invention, the latent heat storage heat exchanger comprises a housing of one material to form the one coupled cavity. The housing comprises a bin part and a cover part, wherein the bin part forms essentially the one coupled cavity. This feature enables one to design a housing that could be manufactured by means of an injection moulding process. The housing could be made from HDPE (High Density Poly Ethylene).
In an embodiment of the invention, the cover part comprises at least one opening for filling the one coupled cavity with the PCM-material. In an embodiment of the invention, the openings are configured for receiving a sealing member. In an advantageous embodiment, the opening and the sealing member are coupled by means of a screwed connection. In another embodiment, the opening and sealing members are coupled by means of gluing or welding.
In a further embodiment, the bin part and the cover part are coupled by means of one continuous circular weld. After the bin part and the cover part are positioned on each other, a heating element having a shape complementary to the exterior shape of the body where the bin part and cover part touches is positioned along the exterior where the cover part and bin part touches. The touching ends of the bin part and cover part will fuse together to form the one continuous circular weld.
It is a further aspect of the invention to provide an improved method of manufacturing a latent heat storage heat exchanger. The method comprises the steps:
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- manufacturing a bin part for a latent heat storage unit according to the invention;
- manufacturing a cover part for a latent heat storage heat exchanger according to the invention;
- welding the bin part and the cover part together to form a body with one coupled cavity according to the invention; and,
- filling the one coupled cavity with a PCM-material.
It is a further aspect of the invention to use a latent heat storage heat exchanger in a climate control system. Furthermore, an aspect of the invention is a reduction in manufacturing costs of a climate control system by including at least one latent heat storage heat exchanger according to the invention in the system.
The invention further pertains to a latent heat storage heat exchanger for holding PCM-material having in at least two of its dimensions and a inside wall spacing of not more than 1 cm and comprising an insert.
The invention further pertains to a climate unit comprising a mobile housing with a ventilation air channel with a ventilation air inlet, a ventilation air outlet, and a heat exchanger comprising PCM between the ventilation air inlet and the ventilation air outlet, and a return air channel separate from said return air channel. The climate unit can form a climate system in combination with other, similar climate units.
It will be evident that the various aspects mentioned in this patent application may be combined and may each be considered separately for a divisional patent application, for instance relating to the latent heat storage heat exchanger, the latent heat storage heat exchanger assembly, or the latent heat storage heat exchanger assemblies stack.
Other features and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings which illustrate, by way of example, various features of preferred embodiments of the invention.
These and other aspects, properties and advantages of the invention will be explained hereinafter based on embodiments shown in the following description with reference to the drawings, wherein like reference numerals denote like or comparable parts, and illustrating in:
First, below and regarding
In the following description, the components will be described starting with the basic building block, the latent heat storage heat exchanger or alternatively the PCM units 51, and ending with the climate system 500 in use.
The housing formed by the bin part 4 and the cover part 2, comprises a plurality of plate shaped elements 6. Each plate shaped element 6 comprises a cavity for receiving PCM. The plate shaped elements 6 are positioned parallel to each other. A predefined spacing 7 is provided between the plate shaped elements 6 to form a fluid channel 7. It should be noted that the invention is not limited to plate shaped elements with a flat surface. For example, the surface could be enlarged, for instance by making the surface curved or corrugated. The plate shaped elements 6 are coupled together to form one housing by means of a coupling structure 8. In the embodiment shown in
The housing of the latent heat storage heat exchanger 1 could also be described in the following way. A plate shaped coupling structure 8 provided with a plurality of plate shaped elements 6 or ribs at both sides of the coupling structure 8. The plate shaped elements 6 extending essentially perpendicular from the plate shaped coupling structure 8. The plate shaped elements 7 are positioned parallel to each other at a predetermined distance. The space between the plate shaped elements 6 forming a fluid channel 7 configured for passing a flow of fluid along the surface of the plate shaped elements 6 to exchange heat between the PCM in the latent heat storage heat exchanger and the fluid passing along the fluid channel 7. A fluid could be a gas or a liquid. In an air ventilation system it is likely that the fluid is a cooled or heated air flow.
A cross section of two adjacent plate shaped elements 6 and the coupling structure 8 between said elements form the shape of a letter H. The two adjacent plate shaped elements 6 correspond to the legs of the letter H and the coupling structure corresponds to the cross of the letter H. The space between the legs of the letter H corresponds to the fluid channel. A latent heat storage as a whole comprises a plurality of H-shaped parts.
Assume that the latent heat storage heat exchanger has an outer profile with the geometry of a rectangular cube. The cube having a length L, a height H and a depth D, wherein L≧H≧D. It thus has a longitudinal axis running through the centre of the plates. To obtain an optimal ratio with respect to contact surface between PCM and fluid channel, cross section of the fluid channel and amount of PCM-material, the coupling structure 8 is parallel to the side having a length L and a width H of the cube. The plurality of plate shaped elements 6 are parallel to the side having a length H and a width D of the cube. Compared with known latent heat storage heat exchangers with a predefined size of for example L=570 mm, H=160 mm and D=148 mm and plate shaped elements parallel to the side having a length L and a width D a significant increase of contact surface and volume of PCM is possible. Furthermore, as the length of the air channel through the latent heat storage heat exchanger decreases and the cross section of the air channel through the unit increases, the air resistance of the latent heat storage heat exchanger when applied in a ventilation system decreases. In the invention, the latent heat storage heat exchangers have equal dimensions in order to make a modular system. As for the dimensions L, H, B, for instance L=500-600 mm, H=100-200 mm and D=100-200 mm can be used. In some embodiments, latent heat storage heat exchangers of halve seize can be used to provide even more flexibility. Usually, the length L is halve of the full seize latent heat storage heat exchanger. The dimensions above allow an optimal load for a throughput of air of 50 m3/h for the full seize latent heat storage heat exchangers and thus 25 m3/h for the halve-seize latent heat storage heat exchangers.
In an embodiment, the plate shaped elements have a thickness that is larger than two times the width of the air channel between two adjacent plate shaped elements, for example a thickness of between 8 and 13 mm, in particular 9-12 mm, for instance around 11 mm. The air channel thus has a width of 3-7 mm, in particular 3-5 mm, for instance around 4 mm. It should be noted that the dimensions of the plate shaped elements and the distance between the plate shaped elements depend on the application of the latent heat storage heat exchanger and relate to parameters such as flow, desired latent heat storage capacity, daily cycles, cooling/heating capacity, medium, etc.
The present invention enables one to manufacture a latent heat storage heat exchanger comprising a plurality of parallel positioned plate shaped elements by means of the following process steps:
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- 1) Produce a bin part with feature described above by means of an injection moulding process from a material such as HDPE;
- 2) Produce a cover part with features described above by means of an injection moulding process from the similar material as the bin part;
- 3) Position the cover part on the bin part;
- 4) Position a heating device along the contour defined by the outer profile of the surface where the cover part is positioned on the bin part;
- 5) Heat the material of the bin part and the cover part near the touching location;
- 6) Fuse the bin part and the cover part in one go to obtain one continuous circular weld (corresponds to the profile of the upper edge of the bin part and the lower part of the cover part) to obtain a housing with one coupled cavity including the cavity formed by the coupling structure and the cavities of the plurality of plate shaped elements;
- 7) Fill in one go the one coupled cavity with a PCM though one or more filling openings; and
- 8) Seal the one or more filling openings with a sealing member.
The method according to the invention enables one to manufacture a plurality of parallel positioned plate shaped elements for use in a climate control system by performing each of the steps 1-8 only once. This has been made possible by providing a coupling structure between the plate shaped elements and which structure comprises a cavity which provides a fluid passage between cavities of the plate shaped elements.
In
The insert in fact divides the larger volume of the storage unit into smaller sub spaces. In fact, in this embodiment it divides a larges space into sub spaces with each dimension smaller than 2.5 cm.
In the embodiment or
In this embodiment, the insert comprises strips that have a width corresponding to the width of the storage unit. Thus, it divides the storage unit in compartments. In this embodiment, strips 21 have a series of crosswise attaches strip parts 21 that are arranged to fit together to functionally form single cross strips 22, Thus, the insert can be formed as series of sub-inserts that are connected via transverse strips 23. In this embodiment for the heat exchanger of
The cross strips 22 are usually perpendicular with respect to the strips 21. The strips 21 in one level are connected via bridging parts 26. These bridging parts can be provided with slots for the transverse strips 23. In yet another embodiment, the entire insert can be formed as one single injection moulding part.
In another embodiment, a similar insert can also be used in order to divide another shaped heat exchanger into sub compartments. Thus, the storage unit can be used in any desired orientation.
In
In an embodiment, the latent heat storage heat exchange unit has another shape than the shown block shape. For instance, in some applications a trapezoid shape is preferred, in order to have heat transfer properties tailored to the need. In another application, when tubes are used, a cylinder shape is preferred. In such a shape, the plates are disks and are essentially parallel with respect to one another. It may even be possible to position the plates of the latent heat exchanger a little off parallel, in order to modify the flow channel.
PCM unit 51 further comprises indentations 57 in at least one facing wall 55, 55′. These indentations 57 are formed through folds in at least one of the facing walls 55, 55′. The indentations 57 provide obstacles inside the blow-moulded container, which increase the life span of the PCM material. In an embodiment, shown in
In order to facilitate filling of the blow-moulded container 52, the indentations 57 run up to a distance from the ends 63,64 of the blow-moulded container 52. In this way, the compartments that are created by the indentations forming partition walls are in fluid communication. Thus, all the created compartments, created though indentations 57, can be filled with PCM via one filling opening 56. In an embodiment, the indentations 57 end shortly before the end walls 63, 64. In an embodiment, the indentations 57 end between 0.3 and 1.5 cm before the ends 63, 64. In a specific embodiment, the indentations end between 0.2 and 1 cm before the ends 63, 64.
In an embodiment, the indentations 57 are made in each of the facing walls 55, 55′ and run up to the inner surface of its opposite facing wall, 55, 55′. In this way, additional to the partitioning function, the indentations 57 also have a function of providing additional strength to the container 52. In an embodiment, the indentations 57 are alternatingly provided in one facing wall 55 and in the opposite facing wall 55′. This further improves dimensional stability of the container 52 when the PCM in use for instance exchanges heat at one side.
In an embodiment, the indentations 57 run substantially parallel to the longitudinal axis of the container 52. In that way, when resting the PCM unit 51 on one of its longitudinal walls 53, 54, the indentations 57 stabilize the PCM material inside the container 52. In an embodiment, the width of the indentations 57 is small. In fact, in an embodiment the inner width A is smaller than 2 mm. In particular, the inner width A of the indentations 57 is below 1.5 mm.
In the embodiment of
The barriers may also extend in both directions. For instance, the indentation 57 may end in a triangular shape or in an indentation that runs almost perpendicular to the indentation 57 for providing a stop or barrier. The stop or barriers prevents the material of the PCM to segregate and flow down over the edge of the indentation wall 61.
As mentioned, the PCM units 51 have a container 52. It was found that using blow-moulding techniques, it is possible to produce containers for the PMC that are leak tight, cheap to produce, and that are dimensionally stable. Dimensional stability is desirable for some applications in which the PCM units 51 are used in a heat-exchanging setting. This is for instance the case in PCM modules that are use in convection units in climate systems. It was found that in such PCM modules, when providing a laminar flow of air along the facing walls (55, 55′), the width of air gaps between the PCM units 51 is to be about 3.7 mm. The rounded shape of the longitudinal walls (53, 54) reduced the air resistance of the PMC units 51 when used in a PCM module comprising a stack of PCM units 51. This shape further reduces the occurrence of turbulence along the facing walls 55, 55′.
The indentations in the facing walls 55, 55′ of the container walls are in an embodiment produced in the blow moulding process. In an embodiment, the indentations 57 are formed from wall material folded inward. This can be produces using thin, elongated elements in the walls of a blow moulding mould that push inward into a container pre-shape. While the container wall 55, 55′ is still hot and highly flowable, these elements push a part of the container wall inward, using that wall material as wall material for the walls 61 of the indentations 57. It may also be possible to use for instance the inner pressure of a blow-moulded container 52 to press the indentation walls 61 onto one another again.
Using the indentations 57, compartments 65 can be created in the blow-moulded container 52. In an embodiment, the distance between indentations 57, i.e., the space B between adjacent indentation walls is less than 2 cm. In particular, to provide a longer working life span of the PCM, the distance B between indentations 57 is less than 1.5 cm. In order not to lose too much volume, the distance B between indentations 57 is in an embodiment more than 0.8 cm.
The container 52 as mentioned is produced using blow moulding. As such, blow moulding is a polymer shaping technique known to a skilled person. In an embodiment, the container is made from HDPE (High Density PolyEthylene) or PP (PolyPropylene).
As mentioned above, a PCM unit 51 of the blow moulded container 52 filled with PCM can be combined with similar PCM units 51 to form a PCM module or PCM latent heat storage heat exchanger, in particular for use in a climate system for at least controlling the temperature in a space in a building. To that end, the PCM units 51 can for instance be combined by placing them with the facing wall of one PCM unit 51 facing an opposite facing wall of a next PCM unit 51.
In an embodiment, as mentioned above, a design limit the flow speed of air can be limited to 2 m/s. Then, a design is made regarding the amount of fresh air that is needed in for instance a building or a space. Furthermore, in the design the amount of heat storage is set. Thus, the required temperatures during for instance a 24-hour cycle us determined. Isolation conditions of a building can be taken into account, as well as the climate outdoors temperature during the year.
For instance, the heat storage capacity is selected to be able to heat or cool a building for 2 working days (for instance 9-11 hours) to a set temperature cycle. That set temperature can be for instance 18 degrees Celsius between 8:00 and 18:00. That set temperature should be maintained with respect to an outside temperature of for instance 2-10 degrees difference (higher and lower) with respect to that set temperature. Furthermore, the required fresh airflow is determined. From these values, a required volume of PCM can be calculated, and the amount of PCM units 51. With an airflow of below 2 m/s passing a PCM unit 51, the configuration of a climate system can be determined.
In order to provide an efficient energy transfer, when using a flow of air, the speed of the air and the dimensions of the channels and space between PCM units 51 is set to provide a laminar flow of air. This in general means setting all the sizes and speeds such that the Reynolds number is below 2000. Additionally flow-guiding plates can be provided in the inlet and exit channel and connecting to the PCM units 51. In an embodiment, these plates are parallel or substantially parallel to the longitudinal direction of the channel.
The indentations 57 of the PCM unit 51 provides grooves that allow insertion of spacers, additional heat conductors, or, like in this embodiment, fixing parts that allows connecting the PCM units to a further part, for instance combined into an alternative latent heat storage heat exchanger that can be used modularly like the latent heat storage heat exchanger of
The latent heat storage heat exchanger assembly 200 of
The latent heat storage heat exchangers 1 are usually free standing provided on the frame units 101.
The frame units 101 provide a support for the latent heat storage heat exchangers. Thus, the L profile ends provide an open frame allowing the air to flow to the latent heat storage heat exchangers. In
In
In order to fix the frame units 101 in their mutual position as for instance indicated in
As mentioned before, the flow channel 110 can be provided in a removeable unit, for instance a container that can be coupled to an inlet of an existing climate control system of a building.
The latent heat storage heat exchanger assembly is usually mounted in a rectangular channel in the following way. The frame with frame units 101, for instance four frame units 101, is provided with each for instance 14 latent heat storage heat exchangers, for instance of the type described in detail above, and that are filled with PCM material. The assembly is in a folded position provided in channel 110. There, the upper frame unit 101 is lifted at the end provided with the channel attachment part 105 and attached to the ceiling of the channel 110. Then, the next frame units are set to their angular positions and the hinges are fixed at their positions to result in the situation shown in
In
The assembly 200 of
In order to force a flow of air between the plate elements of the latent heat storage heat exchangers, a front plate 122 and a rear plate 126 are provided to the most upstream and the most downstream latent heat storage heat exchanger. Plate 122 blocks fluid flows between the plate elements coming from the upstream face of the most upstream latent heat storage heat exchanger. Plate 126 blocks fluid flows to flow out between the plate elements past the downstream face of the most downstream latent heat storage heat exchanger. The plates 122, 126 may have openings in order to further control the fluid flow.
These plates 122, 126 can be clipped on the latent heat storage heat exchangers, or alternatively be coupled to or attached to the outer frame or to the frame unit. Thus, when stacking assemblies of
In the embodiment of
Usually, as mentioned above, the flow speed of air is limited to 2 m/s. Then, a design is made regarding the amount of fresh air that is needed in for instance a building or a space. Furthermore, in the design the amount of heat storage is set. Thus, the required temperatures during for instance a 24 hour cycle is determined. Isolation conditions of a building can be taken into account, as well as the (statistical) climatological outdoors temperature during the year.
For instance, the heat storage capacity is selected to be able to heat or cool a building for 2 working days (or, for instance, 9-11 hours) to a set temperature cycle. That set temperature can be for instance 18 degrees Celsius between 8:00 and 18:00. That set temperature should be maintained with respect to an outside temperature of for instance 2-10 degrees difference (higher and lower) with respect to that set temperature. Furthermore, a required fresh air flow is determined. From these values, a required volume of PCM can be calculated, and the amount of latent heat storage hear exchangers. With an air flow of below 2 m/s passing a latent heat storage heat exchanger, the configuration of a climate system using for instance assemblies 200 of
The assembly 200 here has a channel part with side walls 120, bottom wall 123 and upper wall 124, for allowing an air flow 110. In this channel part, air is introduced with a flow speed such to provide a laminar flow. Usually, the flow speed is below 2.5 m/s. In fact, in most embodiments the flow speed will be as low as in the order of 1-2 m/s. Often, the cross sectional area of the flow channel will be up to 5 m2. Thus, about up to 36000 m3/h can be treated. Often, the channel has a cross sectional area of at least 1 m2. In some of the embodiments, some of the PCM units 1 in the PCM module 200 can be replaced with one or more closed plates in order to modify the capacity of the PCM module 200. Thus, usually at least 100 m3/h will be treated using the PCM module 200. In some specific designs, the module 200 is used for treating 500-5000 m3/h. The angle β (see
The PCM module of
In order to load or charge/discharge a PCM unit 51 uniformly, thus allowing the entire unit to be loaded (i.e., melted and solidifying) uniformly, the spacing along a PCM unit 1 varies less than 5%. Thus, the entire capacity of the PCM unit 51 can be used.
In order to (heat) load each PCM unit 1 to the same amount, the spacing is very accurately defined and varies very little. Thus, the PCM units 51 are positioned accurately in the PCM modules 200. In an embodiment, the difference between the interspacing of the PCM units 51 differs less than 5%. Thus, all PCM units 51 are loaded almost uniformly.
The frame unit 121 is set at an angle β (
In order to force a flow of air 110 between the PCM units 51, a front plate 122 and a rear plate 126 may be provided to the most upstream and the most downstream module. Plate 122 blocks fluid flows between the plate elements coming from the upstream face of the most upstream latent heat storage heat exchanger. Plate 126 blocks fluid flows to flow out between the plate elements past the downstream face of the most downstream latent heat storage heat exchanger. The plates 122, 126 may have openings in order to further control the fluid flow.
These plates 122, 126 can be clipped on the PCM units 51, or alternatively be coupled to or attached to the outer frame or to the frame unit. Thus, when stacking assemblies of
In the embodiment of
In the PCM module of
In
In
Ventilation air channel 407 is for (outside) ventilation air B.L, usually fresh air coming from outside. It has a ventilation air inlet 401. In this embodiment, halve of the front wall is indicated as ventilation air inlet 401. It may be shut off using for instance shutters. The return air channel 405 further comprises an exhaust air A.L exit for air leaving the climate system and the building. Again, this exit 402 can have shutters for closing off or (partially) opening the outlet.
In the embodiment of
In particular, R.L, return air from the building, can be split into flows. One of these split flows is A.L, the exit or exhaust air. Another of these split flows is Re.L, return loop air that will be redirected over the latent heat storage heat exchange assemblies stack 300. This air may be mixed with incoming outside air B.L. In this container, the exhaust air A.L has a passage in a wall of the housing, and a further outlet for coupling to a further similar housing in an adjoining wall.
Before the assemblies stack 300, an air filter 409 is positioned.
In the housing, using walls and closable passages 404, 410, 408 in the walls, air channels can be provided. The closable passage 404, 410, 408, for instance using operable shutters in the walls, provide valves and switches in the air channels 405 and 407, allowing for instance the creation of the return loop by (at least partially) closing passages 404 and 408, and (at least partially) opening passage 410.
Both the ventilation air channel 407 and the return air channel 405 in this embodiment have an air displacement device. Often, a ventilator is used for this purpose, although a skilled person may suggest other air displacement devices in this respect.
The climate unit 400 further has a temperature sensor 414 in the return air channel and a temperature sensor 413 in the ventilation air channel. The temperature sensors provide temperature information to a control device in the housing and to which they are operable coupled, often wired, but also possible via electromagnetic coupling via WIFI, Bluetooth, ZIGBY, or other known coupling means. The control device further provides control instructions to the air displacement devices. The control devices of separate climate units may be operationally coupled with one another, for instance in a wired or wireless network.
In an alternative setting, the coupling channel parts connect opposite side walls and air flows in horizontal direction through climate units.
The climate control system can have one of the following control setups.
Control Schedule 1In control schedule one, a maximum return air temperature control, the following control is used. It has a minimum limitation of the air inlet temperature.
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- a. If a measured temperature of return air for instance using temperature sensor 414 is higher then a measured outside temperature using for instance a temperature of the inflowing ventilation air for instance at inlet 401, then 100% ventilation air B.L, otherwise 100% R.L over the PCM stack;
- b. A maximum set point for the temperature of the return air is set, for instance at 28 degrees C., en a minimum set point for the ventilation air temperature is set to for instance 18 degrees Celsius;
- c. If a measured return air temperature is below the maximum set point and the ventilation air temperature is equal to or higher then the minimum set point, then the ventilation air channel and the exhaust channel are both closed, or ventilators are slowed down;
- d. If the ventilation air temperature is below the minimum set point, then the exhaust channel and the ventilation channel close, and the return valve opens. In this way, more and more warm return air will be added and re-circulated.
- Using this control, the ventilator will run between 0-100% for a temperature of up to 28 degrees C. The valves will allow at 26-100% of ventilation air with a temperature between −10 and 28 degrees C. No ventilation air if the temperature is above 20 degrees C.
In control schedule 2, a minimum ventilation inlet temperature control with a maximum limitation of the return air temperature is used.
-
- a. If a measured return air temperature 414 is higher then a measured ventilation air temperature 413, then 100% ventilation air, otherwise 100% return air;
- b. A minimum set point is set to the minimum ventilation air temperature, for instance at 25 degrees Celsius. A maximum set point is set to the maximum return air temperature, for instance at 35 degrees Celsius.
- c. If a measured return air temperature 414 gets below the max set point and the ventilation air temperature 413 is equal to or below the min set point, then the ventilation air ventilator and the return air ventilator are both slowed down.
- d. If the ventilation air temperature 413 gets below the minimum set point, then the recirculation valve is opened and the return exits and ventilation air valves are closed to provide more air in recirculation.
Using this control, a ventilator will run between 0-100% when the temperature load in a room of building is 0-100%. The valves will allow between 22-83% of ventilation air for a ventilation air temperature of between −10-35 degrees Celsius.
Control Schedule 3In control schedule 3,
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- a. If a measured return air temperature 414 is above a measured ventilation air temperature 413, then 100% ventilation air is used, otherwise 100% recirculation air;
- b. For the ventilator speed a set point of a temperature difference between the return air temperature and the ventilation air temperature (413-414) is set at for instance 10 degrees Celsius. If the temperature difference decreases, then the speed of the ventilation air and of the return air ventilators are both slowed down.
- c. A set point is set for the ventilation air temperature of for instance 20 degrees Celsius. Is the ventilation air temperature get below 20 degrees Celsius, then the return air and ventilation air valves close, and the recirculation valves open more and more to add more warm return air to the ventilation air.
- In this way, the ventilator speed will be between 0-100% to maintain the temperature difference between ventilation air and return air between set point difference.
Note that for each of the control schedules, the lower set point temperature usually is below the melting temperature of the PCM material. In a data hotel design, usually the electronics inside the data hotel or server centre will produce an excess heat. Thus, on average heat must be taken out of the building. The melting temperature is selected relatively high in these situations. In a design, this melting temperature is selected to be between 22 and 26 degrees Celsius, in particular between 23 and 25 degrees Celsius. In these cases, the lower temperature will be selected to be several degrees below the melting temperature. Thus, as long as the return air temperature as well as the ventilation air temperature are below the melting temperature of the PCM material, the flow of air through the PCM stack does not melt the PCM material.
Usually, the invention is used for air flows. However, it may also be used for flows of other fluids. For instance, other gases of mixtures of gases, but also for liquids, for instance water.
The measures described hereinbefore for embodying the invention can obviously be carried out separately or in parallel or in a different combination or, if appropriate, can be supplemented with further measures; it will in this case be desirable for the implementation to depend on the field of application of the device. The invention is not limited to the illustrated embodiments. Changes can be made without departing from the idea of the invention.
Claims
1-29. (canceled)
30. A climate system comprising:
- at least one latent heat storage heat exchanger assembly having: a channel part having an inlet end with a flow cross sectional, an outlet end a flow cross sectional area, and said inlet end defining an incoming air direction; at least one latent heat storage heat exchanger having a plurality of plate shaped PCM units that have a container holding PCM, said PCM units positioned parallel at a spacing d behind one another; and a frame unit providing a support plane for holding said at least one latent heat storage heat exchanger in said channel part, said frame unit mounted with said support plane at an angle between 5 and 45 degrees with respect to the incoming air direction.
31. The climate system of claim 30, wherein:
- said latent heat storage heat exchanger assembly has a support frame providing mutually parallel, opposite upper and lower support surfaces; and
- said frame unit holds the at least one latent heat storage heat exchanger between said upper and lower support surfaces and is mounted at an predetermined angle with respect to the lower support surface.
32. The climate system of claim 30, wherein said frame unit is provided for holding the plate shaped PCM units perpendicular to the support plane or upper and lower support surfaces.
33. The climate system of claim 30, wherein the frame unit provides a support plane for said latent heat storage heat exchanger at a support plane angle of between 5 to 45 degrees.
34. The climate system of claim 30, wherein said support frame comprises a block shaped part formed by plate and/or profile elements which house said frame unit.
35. The climate system of claim 30, wherein the support frame comprises plate walls forming a rectangular channel part, said frame unit being attached in and onto the support frame.
36. The climate system of claim 30, wherein plate shaped PCM units of the latent heat storage heat exchangers are provided mutually parallel and said latent heat storage heat exchanger has a longitudinal axis through said plate shaped PCM units, and which is parallel to said upper and lower support surfaces.
37. The climate system of claim 36, further comprising fluid openings for allowing a fluid flow into and out of said latent heat storage heat exchanger assembly and past said latent heat storage heat exchanger, and a latent heat storage heat exchanger assembly longitudinal axis between said upper and lower support plates and connecting said openings, said latent heat storage heat exchanger assembly longitudinal axis being perpendicular to said latent heat storage heat exchanger longitudinal axis.
38. The climate system of claim 30, further comprising at least two climate units coupled to a building for climate control of air in said building, said climate units comprising a rectangular, box-shaped mobile housing having housing walls and includes:
- the latent heat storage heat exchanger assembly inside said housing;
- a ventilation air channel in said rectangular, box-shaped mobile housing and including said heat exchanger, said ventilation air channel provided to pass ventilation air from a ventilation inlet of said rectangular, box-shaped mobile housing via and through said heat exchanger out to a ventilation outlet of said rectangular box-shaped mobile housing;
- a return air channel through said rectangular, box-shaped mobile housing for transporting return air from a return air inlet of said rectangular, box-shaped mobile housing to an exhaust air outlet of said rectangular, box-shaped mobile housing;
- a ventilation air channel coupling channel part in fluid communication with said ventilation air channel, connecting opposite housing walls, and having opposite coupling passages in said opposite housing walls for allowing coupling of ventilation air channels of further, similar climate units; and
- a return air channel coupling channel part in fluid communication with said return channel, connecting opposite housing walls, and having opposite coupling passages in said opposite housing walls for allowing coupling to return air channels of other, similar climate units, and wherein said climate units are positioned with said ventilation air channel coupling channels parts in fluid communication and with their return air channel coupling channel part in fluid communication, allowing said climate units to be coupled selectively in series and parallel.
39. The climate system of claim 38, wherein said return air channel coupling part and ventilation air coupling part positioned with a coupling passage in the same housing wall to allow coupling of said ventilation air channel and said return air channel to one and the same similar climate unit.
40. The climate system of claim 38, wherein part of said ventilation air channel is formed by opposite housing wall parts, at least part of that ventilation air channel part forming said coupling channel part.
41. The climate system of claim 38, wherein in operation said ventilation air channel has a flow direction from an upstream end of said ventilation air channel at said ventilation inlet to a downstream end of said ventilation air channel at said ventilation outlet, and said opposite housing wall parts are side walls of said ventilation air channel.
42. The climate system of claim 38, wherein upstream and downstream ends of one of said ventilation air channel and said return air channel are formed by opposite housing walls.
43. The climate system of claim 38, wherein said ventilation air channel coupling channel part is perpendicular with respect to said ventilation air channel.
44. The climate system of claim 38, wherein part of said return air channel is formed by opposite housing wall parts, at least part of that return air channel part forming said coupling channel part.
45. The climate system of claim 38, wherein in operation said return air channel has a flow direction from an upstream end of said return air channel at said return air inlet to a downstream end of said return air channel at said return air outlet, and said opposite housing wall parts are side walls of said return air channel.
46. The climate system of claim 38, wherein said return air channel coupling channel part is perpendicular with respect to said return air channel.
47. The climate system of claim 38, wherein said ventilation air channel coupling channel part is provided inside said housing at said return air channel end.
48. The climate system of claim 38, wherein part of at least one of said coupling channel parts is formed by part of a further wall connecting both opposite walls, said further wall having a selectively operable passage for providing one of said ventilation outlet and said exhaust air outlet.
49. The climate system of claim 38, wherein said return air channel coupling channel part is provided inside said housing at a return air channel downstream end.
Type: Application
Filed: Aug 1, 2012
Publication Date: Jan 29, 2015
Inventor: Antonius Henricus Hubertus Schmitz (Posterholt)
Application Number: 14/236,622
International Classification: F28F 9/007 (20060101);