HVAC SYSTEM FOR BUILDINGS
A ventilation system comprises a plurality of axial fan units, each having at least one axial fan having a rotational axis generally parallel to a downstream flow caused by the axial fan, and at least one grill positioned adjacent to the at least one axial fan in a downstream flow path of the axial fan unit, the at least one grill directing an air flow of the axial fan. At least a first series of the plurality of axial fan units is adapted to be positioned at a top of a plenum arrangement extending from a bottom front of a refrigerated enclosure, to a rear back of the refrigerated enclosure, said top being at a top of the rear back. At least a second series of the plurality of axial fan units is adapted to be positioned above an area to cool and oriented to project its downstream flow in a downward direction to direct its downstream flow to said area to cool. The first series of the plurality of axial fan units is oriented to project its downstream flow in an upward direction toward the second series of the plurality of axial fan units such that the first series is adapted to direct air from the plenum arrangement to the second series.
The present application relates to ventilation systems for buildings and refrigeration systems found in medium scale and large scale surfaces, such as those found in supermarkets for refrigerated counters and enclosures, in relation to HVAC needs (heating, ventilation and air conditioning).
BACKGROUND OF THE ARTSupermarkets of medium scale and large scale surfaces conventionally have many alleys equipped with rows of refrigerated counters and enclosures. The refrigerated counters and enclosures come in various forms, and are commonly found in open configuration. In the open configuration, there is no door to maintain the cold inside the counters. Islands, semi-vertical enclosures, multi-deck vertical enclosures may have an open configuration.
As a result of the open configuration, the ambient temperature in the vicinity of refrigerated counters may be uncomfortably low. For example, in the warmer months of a year, or in warmer climates, shoppers may be dressed lightly based on the outdoor temperature, and may consequently find unpleasant the shopping experience when walking through alleys of refrigerated enclosures. Supermarkets are thus equipped with HVAC systems to climate different sections of supermarkets. This may include generating heat for cooler sections of the supermarket in spite of the warm outdoor temperature, and operating an air-conditioning cycle to cool other sections of the supermarket. Such use may be inefficient in terms of energy costs, with the usual drawbacks also present: carbon footprint of energy consumption, global warming, etc.
SUMMARYIn one aspect, a ventilation system comprising: a plurality of axial fan units, each having at least one axial fan having a rotational axis generally parallel to a downstream flow caused by the axial fan, and at least one grill positioned adjacent to the at least one axial fan in a downstream flow path of the axial fan unit, the at least one grill directing an air flow of the axial fan; wherein at least a first series of the plurality of axial fan units is adapted to be positioned at a top of a plenum arrangement extending from a bottom front of a refrigerated enclosure, to a rear back of the refrigerated enclosure, said top being at a top of the rear back; wherein at least a second series of the plurality of axial fan units is adapted to be positioned above an area to cool and oriented to project its downstream flow in a downward direction to direct its downstream flow to said area to cool; and wherein the first series of the plurality of axial fan units is oriented to project its downstream flow in an upward direction toward the second series of the plurality of axial fan units such that the first series is adapted to direct air from the plenum arrangement to the second series.
In another aspect, a refrigeration controller system for operating a refrigeration, a ventilation system and a HVAC system comprising: a processing unit, and a non-transitory computer-readable memory communicatively coupled to the processing unit and comprising computer-readable program instructions executable by the processing unit for operating the refrigeration system to cool refrigerated enclosures; operating the ventilation system as described above to provide cold heat to a facility recuperated from said refrigerated enclosures; reclaiming heat from the refrigeration system; and operating the HVAC system with the heat reclaimed from the refrigeration system to provide heated air; wherein the refrigeration controller system operates when an outdoor temperature is greater than 20 C.
In another aspect, there is provided a heating, ventilating and air conditioning (HVAC) system, comprising: a central unit, comprising: a compressor operable to provide compressed refrigerant, a condenser at a refrigerant inlet fluidly connected to a refrigerant outlet of the compressor via a compressed refrigerant line to receive the compressed refrigerant from the compressor, and a first fan operatively connected to the condenser to move air through the condenser; a plurality of terminal units, each terminal unit of the plurality of terminal units comprising, in serial air flow communication: a cooling coil fluidly connected: at a refrigerant inlet thereof, to a refrigerant outlet of the condenser to receive refrigerant from the condenser, and at a refrigerant outlet thereof, to a refrigerant inlet of the compressor to supply evaporated refrigerant to the refrigerant inlet of the compressor; a heating coil fluidly connected: at a refrigerant inlet thereof, to the compressed refrigerant line at a first location that is fluidly between the refrigerant outlet of the compressor and the refrigerant inlet of the condenser, and at a refrigerant outlet thereof, to the compressed refrigerant line at a second location that is fluidly between the first location and the refrigerant inlet of the condenser; and a second fan operable to move air through the cooling coil and the heating coil.
Referring to
The refrigerated enclosures A are typically add-on equipment. As such, there may be plenums E1 and E2 defined respectively at a bottom and at a back of the refrigerated enclosures A. The plenum E1 is between the bottom of the refrigerated enclosures A and the ground, whereas the plenum E2 is between the back of the refrigerated enclosure A and a wall or structure against which the refrigerated enclosures A have their back, such as another row of refrigerated enclosures A, a row of shelves, etc.
The ventilation system 10 has axial fan units 20 (
The axial fan unit 20/20′ is said to be axial in that an axis of rotation of the fan(s) 21 is generally parallel to a flow direction out of the fan unit 20. The axis of rotation of the axial fan unit 20 would project out of the page for
Referring to
As shown below, in the ventilation system 10, the axial fan units 20/20′ are oriented and configured with the grills 24 to direct the air in a given cycle. More specifically, the axial fan units 20′ are mounted to a top of refrigerated enclosures A, such that the axial fans 21 are aligned with the plenum E2. Therefore, air from the plenums E1 and E2 is drawn by the axial fan units 20′, in such a way that a vacuum or like pressure differential is created at an end of the plenum E1 facing the alley B. Cold air of the alley B consequently flows into the plenum E1, as a result of the action of the axial fan units 20′.
The ventilation system 10 also features the axial fan units 20 mounted above the alley B in the air space C, and oriented to blow air downwardly. The axial fan units 20 may be suspended from the ceiling D, by any appropriate attachment, such as rods, chains, etc. The axial fan units 20 are spaced apart from the ceiling D, to form a gap F. The gap F may for instance have a height ranging from 6 inches to 24 inches, though it may be more or less.
Therefore, the cold air blown upwardly by the axial fan units 20′ is redirected toward the alley B by the axial fan units 20. However, the air drawn by the axial fan units 20 to the gap F includes ambient air of the air space C, which air is warmer than the air in the alley B. Therefore, the air blown downwardly is a mixture of cold air from the refrigerated enclosures A and warm air of the air space C, resulting in an increase in the temperature average of the air in alley B.
According to an embodiment, a normal to the plane of the front face 22A of the axial fan units 20′ is aligned with the gap F. Stated differently, the normal crosses the gap F. Such an embodiment ensures that a fair amount of cold air is drawn by the axial fan units 20. In an embodiment, the angle θ is determined as a function of the ceiling height to achieve a generally direct air path from the axial fan units 20′ to the gap F. An installer may also orient the axial fan units 20′ to achieve such a generally direct air path.
Referring to
Referring to
The refrigeration system 50 may have one or more of a compression stage 51, a condensation/heat reclaim stage 52 (shown as having a condensing stage 52A and a reclaim stage 52B, concurrently 52), an expansion stage 53, and an evaporation stage 54, feeding the refrigerated enclosures A, to then cycle back to the compression stage 51. For example, the refrigeration system 50 may be without an expansion stage. In the refrigeration cycle, the compression stage 51 performs a compression of a refrigerant to a high-pressure gas state. The compression stage 51 is in fluid communication with the condensation/heat reclaim stage 52.
The condensation/heat reclaim stage 52 releases heat from the high-pressure gas refrigerant received from the compression stage 51. In the condensing stage 52A, the heat is released to the atmosphere, for instance using roof-top condensers. Alternatively, heat may be recuperated using heat reclaim systems of a heat reclaim stage 52B in series or in parallel with condensers. According to an embodiment, as described below, the heat reclaim stage 52B provides heat to a HVAC system 70. The condensation/heat reclaim stage 52 may have refrigerant tanks to accumulate refrigerant having released heat and ready to be fed to the evaporation stage 54.
The condensed refrigerant is directed to the evaporation stage 54. The evaporation stage 54 typically has numerous evaporators in the refrigeration enclosures A, as well as the necessary expansion valves in the expansion stage 53 if required to set the refrigerant to a suitable condition to absorb heat. In some instances, the evaporators of the evaporation stage 54 may be flooded with liquid refrigerant such that expansion valves are optional.
In
The available cold heat may exceed the air-conditioning demand, to the extent that HVAC 70 may be required to provide heat to its ventilated air. As shown in
Consequently, the refrigeration controller 60 may be triggered to provide heat when the floor temperature is below a given threshold. The refrigeration controller 60 may actuate appropriate valves for the refrigeration system 50 to direct its refrigerant to the heat reclaim stage 52B. In parallel, the refrigeration controller 60 may actuate the fans of the HVAC system 70 for air to be convected through the HVAC system 70, and in the process be warmed up by the heat reclaim relation with the heat reclaim stage 52B. The warm air may then be supplied to the facility via the ventilation ducts of the HVAC system 70. The refrigeration controller 60 directs such operation, while in parallel the ventilation system 10 operates to meet the air-conditioning demand of the facility.
An advantage of using the heat reclaim stage 52B resides in the reduced load on the condensing stage 52A. As heat is reclaimed by the HVAC system 70, the condensing units of the condensing stage 52A have a lesser amount of heat to release. It has been known that a liquid may be used to assist the heat release of the condensing stage 52 (e.g., water sprayed on the coils of the condensing units). The use of a cooling liquid may not be required when the HVAC system 70 reclaims the heat, whereby the refrigeration controller 60 may block the operation of water sprays. There results a dehumidification of the facility.
In all, the refrigeration controller 60 operates the systems 10, 50 and 70, in such a way that the air-conditioning/refrigeration cycle of the HVAC system 70 may need not be operated, or may only be minimally operated, in spite of an outdoor temperature above 20 C, or above 25 C, or above 30 C, depending on the floor size.
Now referring to
Only some of the refrigerant lines (R) are labeled in
Referring to
Only two of the terminal units 88, a horizontal terminal unit 88, and a vertical terminal unit 88′, are shown in
The supply of refrigerant from the refrigerant outlet 86B of the condenser 86 may be used to enable the one or more terminal units 88 to cool one or more of the spaces (SP1, SP2, . . . SPn) in the building (BLDG). In turn, for cooling the refrigerant passing through the condenser 86 to make the supply of refrigerant from the refrigerant outlet 86B available, the central unit 82 further includes a fan 90. The fan 90 is operatively connected to the condenser 86 to move air through the condenser 86 and thereby carry away heat from the refrigerant passing through the condenser 86. The fan 90 may be any suitable fan and/or may be multiple fans 96. The central unit 82 may have other elements that may be selected to enable operation of the central unit 82 as described herein in each particular embodiment and application thereof. Such additional elements, such as one or more air filters, refrigerant filters, controller(s), valve(s), sensor(s), and the like, may be conventional and are therefore not described in detail herein.
As an example, the central unit 82 may include and/or may be connected to one or more controllers 91, such as conventional controller(s) for example, selected to provide the functionality described herein. In some embodiments, the controller(s) 91 may be the controller 60 described above. As shown, the one or more controllers 91 may be operatively connected to the respective components of the HVAC system 80, including the compressor 84, the fan 90, control valves, sensors and the like, to operate the central unit 82 and the rest of the HVAC system 80 according to a suitable control sequence. The respective electronic connections and control sequences may be conventional and are therefore not described herein in detail.
The present embodiment of the refrigerant line (R) arrangement and two of the terminal units 88 shown in
Still referring to
As shown in
In this embodiment, to help prevent backflow of the refrigerant from the second location (L2) toward the first location (L1), the HVAC system 80 further includes a check valve 98 in the compressed refrigerant line (R) fluidly connecting the first and second locations (L1), (L2). The check valve 98 is oriented to allow refrigerant flow from the first location (L1) toward the second location (L2) and to prevent refrigerant flow from the second location (L2) toward the first location (L1). In other embodiments, a different flow arrangement may be used. The check valve 98 is one of numerous valves that may be present, and that include pressure-regulating valves, e.g., for transcritical operation (which may be at 92), manual, valves, etc.
In this embodiment, refrigerant flow to respective ones of the cooling 93 and the heating coil 94 are controlled via respective dedicated refrigerant flow control valves 98, 100. As shown, in this embodiment, the refrigerant flow control valve 98 controlling refrigerant flow through the cooling 93 is fluidly upstream of the refrigerant inlet 93A of the cooling 93. Similarly, the refrigerant flow control valve 100 controlling refrigerant flow through the heating coil 94 is fluidly upstream of the refrigerant inlet 94A of the heating coil 94. The valves 98, 100 in this embodiment are operatively connected to the controller 91 to be operable by the controller 91 according to a control sequence that may be selected to be suit each particular embodiment and application of the HVAC system 80.
As shown in
Also as shown in
In operation, the controller(s) 91 of the HVAC system 80 may monitor one or more control sequences and variables in one or more of the spaces (SP1, SP2, SPn), such as temperatures, relative humidity, and occupancy for example, with the particular set of variables being selected to suit each particular embodiment and application of the HVAC system 80. As an example, as mentioned above, in the embodiment shown in
In this embodiment of the building (BLDG), the horizontal terminal unit 88 is installed to move air from the top portion (TP) of the occupied space (SP1) toward the top portion (TP) of the occupied space (SP2). The occupied space (SP1) includes a refrigerated enclosure (A), such as a food refrigerator, disposed proximate a wall (W) of the occupied space (SP1) at a rear (AR) of the refrigerated enclosure (A) and proximate a floor (FL) of the occupied space (SP1) at a bottom (AB) of the refrigerated enclosure (A). Further, an axial fan unit 20′, as described above with respect to other embodiments, is disposed proximate a top (AT) of the refrigerated enclosure (A). The axial fan unit 20′ is oriented relative to the space (SP1) to direct air from a space/plenum (E2) defined between: the rear (AR) of the refrigerated enclosure (A) and the part of the wall (W) facing the rear (AR) of the refrigerated enclosure (A). As shown with airflow arrows (unlabeled) in
Still referring to
The air may then be entrained, by negative pressure generated by the axial fan unit 20′ in the space/plenum E2, first into the space/plenum E1 below the bottom (AB) of the refrigerated enclosure (A), then into the space/plenum E2, and may then propel the air to the inlet 88A of the horizontal terminal unit 88. The horizontal terminal unit 88 may then move the air to an air inlet 20A of the axial fan unit 20′. Finally, the axial fan unit 20′ may move the air down into the bottom portion (BP) of the occupied space (SP2). These airflows are shown with unlabeled airflow arrows in
In some embodiments, the bottom portion (BP) of the occupied space (SP2) may be the portion of the occupied space (SP2) that is occupied by visitors to the building (BLDG). In some embodiments, this arrangement of units and resulting airflows may help reduce or eliminate overcooling of the bottom portion (BP) of the space (SP1), which may be the portion that is occupied by visitors to the building (BLDG). In some embodiments, this may allow to reduce or eliminate heating that may otherwise be required to counteract overcooling of the bottom portion (BP) of the space (SP1). Accordingly, in some embodiments, the arrangement of units and resulting airflows described above may help reduce energy consumption of the building (BLDG).
To help further improve efficiency of the HVAC system 80, in this embodiment the horizontal terminal unit 88 is spaced from the ceiling (CLG) to define an air plenum (PL) between the horizontal terminal unit 88 and the ceiling (CLG). Similarly, the axial fan unit 20′ is spaced from the ceiling (CLG) to define an air plenum (PL) between its air inlet 20A and the ceiling (CLG). In some operating conditions of the building (BLDG), hot air from one or more of the spaces (SP1), (SP2) (SPn) may rise and collect in these plenums (PL), and may be mixed with the cooler air coming from one or more axial units 20′ that may be disposed at the top-rear of one or more refrigerated enclosures (A) in one or more of the spaces (SP1), (SP2) (SPn), as described above with regard to the refrigerated enclosure (A) in space (SP1).
In some cases and operating conditions, such mixing of warmer air with colder air in the plenums (PL) and subsequent delivery to one or more occupied portions of the one or more of the spaces (SP1), (SP2) (SPn) may help improve occupant comfort in the one or more of the spaces (SP1), (SP2) (SPn). This mixing may also help reduce energy consumption of the HVAC system 80 by “passively” reheating the cold(er) air entering the plenums (PL) with the warm or hot air in the plenums (PL). Here, the term “passively” is used to mean “without having to generate additional heat via a source such as electricity or combustion of a fuel”.
For cases where the passive reheat may be insufficient, the controller(s) 91 may be programmed to open the control valve(s) 100 associated with the heating coils 94 of the corresponding one or more of the terminal units 88 and may thereby actively reheat air before it is supplied to the occupied portions of the spaces (SP1), (SP2) (SPn). To this end, and as shown in
Yet further as shown in
More particularly, the refrigerant inlet 104A is fluidly connected to a compressed refrigerant line (R) at the first location (L1) described above. In this embodiment, at a refrigerant outlet 104B thereof, the heat exchanger 104 is fluidly connected to a compressed refrigerant line (R) at the second location (L2) described above. Although not shown herein, similar to the heating coils 94, refrigerant flow through the heat exchanger 104 may be controlled via one or more suitable control valves that may be fluidly upstream or downstream of the heat exchanger 104, relative to refrigerant flow therethrough. In use, refrigerant from the outlet 84B of the compressor 84 may be directed through the heat exchanger 104 and may heat water in the domestic hot water tank 102, making it available for various uses in the building (BLDG) via a conventional domestic hot water supply (DHWS).
In at least some applications and operating conditions such as for example times when the building (BLDG) experiences predominantly or solely cooling loads, using heat removed from the spaces (SP1), (SP2) . . . (SPn) in a water unit such as the domestic hot water tank 102 may help cool refrigerant before it reaches the inlet 86 of the condenser 86. This may help reduce an energy consumption of the HVAC system 80.
The above description is meant to be exemplary only. The components and parts described herein above may be constructed from existing components and parts to provide for the particular arrangements of systems and functionality described herein above. One skilled in the art will recognize that changes may be made to the embodiments described without departing from the scope of the technology disclosed herein. Certain aspects of the above systems, such as temperature and/or humidity and/or occupancy sensors one or more of which may be used in some embodiments for example, have not been shown and/or described in detail herein. Where this is the case, the aspects may be implemented using conventional technology.
Claims
1. A ventilation system comprising:
- a plurality of axial fan units, each having at least one axial fan having a rotational axis generally parallel to a downstream flow caused by the axial fan, and at least one grill positioned adjacent to the at least one axial fan in a downstream flow path of the axial fan unit, the at least one grill directing an air flow of the axial fan;
- wherein at least a first series of the plurality of axial fan units is adapted to be positioned at a top of a plenum arrangement extending from a bottom front of a refrigerated enclosure, to a rear back of the refrigerated enclosure, said top being at a top of the rear back;
- wherein at least a second series of the plurality of axial fan units is adapted to be positioned above an area to cool and oriented to project its downstream flow in a downward direction to direct its downstream flow to said area to cool; and
- wherein the first series of the plurality of axial fan units is oriented to project its downstream flow in an upward direction toward the second series of the plurality of axial fan units such that the first series is adapted to direct air from the plenum arrangement to the second series.
2. The ventilation system according to claim 1, wherein the at least one grill is at least one double louver grill.
3. The ventilation system according to claim 2, wherein a plurality of vents defined by the double louver grill each have a rectangular shape having a length ranging between 0.375″ and 1.125″.
4. The ventilation system according to claim 3, wherein the plurality of vents defined by the double louver grill each have a width ranging between 0.375″ and 1.125″.
5. The ventilation system according to claim 3, wherein the plurality of vents defined by the double louver grill each have a depth of at least 0.25″.
6. The ventilation system according to claim 1, comprising one of the at least one grill for each said axial fan unit.
7. A refrigeration controller system for operating a refrigeration, a ventilation system and a HVAC system comprising: a non-transitory computer-readable memory communicatively coupled to the processing unit and comprising computer-readable program instructions executable by the processing unit for
- a processing unit, and
- operating the refrigeration system to cool refrigerated enclosures;
- operating the ventilation system according to claim 1 to provide cold heat to a facility recuperated from said refrigerated enclosures;
- reclaiming heat from the refrigeration system; and
- operating the HVAC system with the heat reclaimed from the refrigeration system to provide heated air;
- wherein the refrigeration controller system operates when an outdoor temperature is greater than 20 C.
8. A heating, ventilating and air conditioning (HVAC) system, comprising:
- a central unit, comprising: a compressor operable to provide compressed refrigerant, a condenser at a refrigerant inlet fluidly connected to a refrigerant outlet of the compressor via a compressed refrigerant line to receive the compressed refrigerant from the compressor, and a first fan operatively connected to the condenser to move air through the condenser;
- a plurality of terminal units, each terminal unit of the plurality of terminal units comprising, in serial air flow communication: a cooling coil fluidly connected: at a refrigerant inlet thereof, to a refrigerant outlet of the condenser to receive refrigerant from the condenser, and at a refrigerant outlet thereof, to a refrigerant inlet of the compressor to supply evaporated refrigerant to the refrigerant inlet of the compressor; a heating coil fluidly connected: at a refrigerant inlet thereof, to the compressed refrigerant line at a first location that is fluidly between the refrigerant outlet of the compressor and the refrigerant inlet of the condenser, and at a refrigerant outlet thereof, to the compressed refrigerant line at a second location that is fluidly between the first location and the refrigerant inlet of the condenser; and a second fan operable to move air through the cooling coil and the heating coil.
9. The HVAC system of claim 8, wherein the plurality of terminal units includes a horizontal terminal unit configured such that the second fan of the horizontal terminal unit ejects air out of the horizontal terminal unit in a horizontal direction when the horizontal terminal unit is installed.
10. The HVAC system of claim 9, wherein the second fan of the horizontal terminal unit is a plurality of axial fans.
11. The HVAC system of claim 8, wherein the plurality of terminal units includes a vertical terminal unit configured to supply air in a vertical direction when the vertical terminal unit is installed.
12. The HVAC system of claim 11, wherein the second fan of the vertical terminal unit is a single axial fan.
13. The HVAC system of claim 8, further comprising a check valve in the compressed refrigerant line fluidly between the first and second locations, the check valve oriented to allow refrigerant flow from the first location toward the second location and to prevent refrigerant flow from the second location toward the first location.
14. The HVAC system of claim 8, further comprising a water unit a volume for storing water and a heat exchanger disposed in the volume, the heat exchanger fluidly connected:
- at a refrigerant inlet thereof, to the compressed refrigerant line at the first location, and
- at a refrigerant outlet thereof, to the compressed refrigerant line at the second location.
15. The HVAC system of claim 14, wherein the water unit is a domestic hot water tank.
16. The HVAC system of claim 8, further comprising a refrigerant expansion valve fluidly between the refrigerant outlet of the condenser and the refrigerant inlets of the cooling coils of the plurality of terminal units.
17. The HVAC system of claim 8, further comprising a refrigerant flow control valve fluidly upstream of the refrigerant inlet of the heating coil of each of the plurality of terminal units.
18. The HVAC system of claim 8, wherein the refrigerant flow control valve is a first refrigerant flow control valve and further comprising a second refrigerant flow control valve fluidly upstream of the refrigerant inlet of the cooling coil of each of the plurality of terminal units.
Type: Application
Filed: Nov 29, 2019
Publication Date: Jun 25, 2020
Inventor: SERGE DUBE (ST-ZOTIQUE)
Application Number: 16/699,380