Device and method for storing and regenerating a two-phase coolant fluid

Abstract

The invention concerns a device for storing a two-phase coolant fluid (4) designed to circulate in a heat transfer circuit (10), comprising: a compartment (2) for storing and regenerating the two-phase coolant fluid; at least an indirect heat exchange means (6) between a refrigerant and the coolant fluid (4); a circulating means (8) to circulate the coolant fluid (4) in the heat transfer circuit (10); a two-phase recycling and cooling circuit for the coolant fluid (4). Said device comprises: another compartment for ice slurry conditioning (20), connected to the heat transfer circuit (10); means for introducing part of the coolant fluid (4), enriched in solid phase, into said other compartment; a drawpoint (24) on the storage and regeneration compartment (2), and means for injecting (26, 28) the coolant fluid in liquid phase, into said other compartment; and a mixing member, co-operating with said other compartment.

Description

[0001] The present invention relates to the storage and regeneration of a cooling fluid.

[0002] The term “ice slurry” is to be understood as meaning a cooling fluid comprising two phases of the same body in melting/crystallization equilibrium, for example water to which an antifreeze agent such as salt, alcohol, monoethylene glycol or monopropylene glycol has been added. This body in melting equilibrium may also be a eutectic. The solid phase in divided form, for example ice microcrystals, is distributed uniformly through the liquid phase, to the extent of obtaining a pasty or viscous consistency of the cooling fluid that is, for example, fluid enough that the said fluid can be pumped. The cooling fluids considered according to the invention are therefore obtained, stored, transported and used in mixed and homogenous two-phase form, particularly in a consistency similar to that of a sorbet or ice slurry.

[0003] Cooling fluids comprise a liquid phase and a solid phase in homogeneous mixture. These are themselves generally mixtures of water and alcohol, water and ethylene glycol, water and propylene glycol, water and glycerol, water and ammonia, water and potassium carbonate, water and calcium chloride, water and magnesium chloride, water and potassium acetate, etc; other types of mixture, not containing water, may also be suitable.

[0004] Such cooling fluids perform very well; they absorb heat by the melting of their solid phase, as opposed to conventional liquid cooling fluids which absorb heat only by heating up (appreciable heat).

[0005] To simplify the explanation of the invention, mention will be made hereinafter of a cooling fluid of the ice slurry type, which must be understood to be a fluid as previously defined.

[0006] Cooling fluid in the liquid phase must be understood as meaning, on the other hand, fluid essentially in the liquid phase, that is to say with a low, if not zero, concentration of microcrystals.

[0007] Document U.S. Pat. No. 2,902,839 discloses a device for storing and regenerating a cooling fluid, in two-phase form, but not in the form of ice slurry, intended to circulate solely in liquid form through a heat transfer circuit. The latter comprises one or more heat exchangers for the exchange of heat between the cold and liquid-form cooling fluid and the outside.

[0008] Said device comprises:

[0009] a storage compartment for storing the cooling fluid in the two-phase state, in melting equilibrium;

[0010] at least one indirect heat-exchange means for the exchange of heat between a refrigerant fluid and the cooling fluid, in liquid phase, associated with said compartment and more specifically arranged inside said compartment;

[0011] a circulation means of the pump type, for circulating the cooling fluid, drawn from said compartment in the liquid state in the cold state, in the heat-exchange circuit and for reinjecting it into said compartment;

[0012] a two-phase recycling and cooling circuit for recycling and cooling the cooling fluid, within said compartment, comprising a tapping point at the lower part of said compartment, said recycling circuit incorporating the indirect heat-exchange means and comprising a means for withdrawing/discharging the cooling fluid.

[0013] The indirect heat-exchange means is an exchanger with a scraped surface, generating a mass setting of the cooling fluid over a scraping surface. Separation of the cooling fluid in solid form from the scraping surface requires significant force, thus going against the idea of reducing the operating energy consumption of the device.

[0014] EP 0 629 826 discloses a cold transfer device comprising a vertical compartment intended to store and to supply a heat-transfer circuit with a cooling fluid of the ice slurry type. The device comprises an indirect heat-exchange means for the exchange of heat between a refrigerant fluid and the cooling fluid, this device being placed outside the storage chamber. It is pumped in liquid phase from a lower level of the storage compartment to be reinjected at a higher level once it has been enriched with microcrystals of the solid phase.

[0015] An extraction means is also provided for supplying the heat-transfer circuit with cooling fluid of the ice slurry type. This extraction means comprises a cone opening onto a duct in the storage compartment. The opening of the cone is at a higher level and where the cooling fluid is rich in solid phase (ice microcrystals). An agitating means is arranged in the cone, so as to create turbulence in the extracted cooling fluid, regenerating the ice slurry.

[0016] Such a device does not allow precise control over the concentration of microcrystals in the cooling fluid of ice slurry type extracted to feed the heat transfer circuit. Furthermore, the supply to the indirect heat-exchange means is under the hydraulic pressure for the cooling fluid contained in the storage compartment. This may prove to be troublesome during maintenance operations especially, when the storage compartment is very large. A significant storage head of ice slurry may, with certain mixtures, lead to a stratification which may appreciably damage the quality of the ice slurry injected into the installation. Drying-out of the top layer may occur, leading to non-optimum temperature. This disadvantage is all the more pronounced if the ice slurry is not in constant use.

[0017] Also known is a method for storing and regenerating cooling fluid in two-phase form, intended to supply in liquid form one or more heat exchangers belonging to a heat-transfer circuit, consisting in:

[0018] (a) having a cooling fluid comprising a solid phase in melting equilibrium with a liquid phase;

[0019] (b) circulating the cooling fluid in liquid form through a circuit comprising the heat exchanger or exchangers and through a storage and regeneration compartment associated with an indirect heat-exchange means;

[0020] (c) storing the cooling fluid in the compartment to allow the liquid phase and solid phase of said fluid to separate;

[0021] (d) tapping from said compartment the cooling fluid essentially in the liquid phase and circulating it through the indirect heat-exchange means so as to convert it to a solid phase, which is broken down into microcrystals;

[0022] (e) reinjecting the cooling fluid rich in microcrystals leaving the indirect heat-exchange means into said compartment.

[0023] The object of the present invention is to store and to regenerate, constantly, a cooling fluid, of the ice slurry type, so that it is permanently operational, even after long periods of shut down.

[0024] Another object of the present invention is to optimize the consistency of a cooling fluid of the ice slurry type, that is to say to optimize the concentration of microcrystals in the cooling fluid and, in particular, to control this concentration, in order to obtain the maximum storage.

[0025] Another objective of the present invention is to control and to alter, as appropriate, this concentration of microcrystals with a view to improving or adapting the refrigerating properties of the cooling fluid of the ice slurry type, in use.

[0026] An additional object of the present invention is to simplify the installations employing such a cooling fluid, on the one hand, and to facilitate the maintenance operations, on the other.

[0027] According to the invention, the device comprises:

[0028] another compartment for conditioning in the form of ice slurry, connected to the heat-transfer circuit, itself supplied with cooling fluid of the ice slurry type;

[0029] means for introducing some of the cooling fluid enriched in solid phase, outside of the indirect heat-exchange means, into said other compartment, at a higher level;

[0030] a complementary tapping point on the storage and regeneration compartment, in the lower part, and injection means for injecting cooling fluid, in liquid phase, into said other compartment;

[0031] and a mixing member, collaborating with said other compartment, for mixing the liquid and solid phases of the cooling fluid.

[0032] Furthermore, the method according to the invention differs from the method identified hereinabove with reference to the steps named (a) to (e) in that:

[0033] (f) some of the solid-phase-rich cooling fluid is separated and stored in another conditioning compartment in the form of ice slurry;

[0034] (g) some of the solid-phase-lean cooling fluid tapped from the storage and regeneration compartment is injected into said other compartment;

[0035] (h) the solid and liquid phases of the cooling fluid are mixed in said other compartment;

[0036] (i) the cooling fluid obtained in (h) is used to carry out step (a) by tapping cooling fluid conditioned in the from of ice slurry from said other compartment and it is reinjected, downstream of the heat exchanger or exchangers of the heat-transfer circuit into the storage and regeneration compartment, and/or for example at the inlet to the indirect heat-exchange means.

[0037] According to one embodiment of the device according to the invention, the indirect heat-exchange means comprises:

[0038] a crystallization chamber provided, on the one hand, with at least one tapping orifice for solid-phase-lean cooling fluid, communicating with the storage and regeneration compartment in the lower part and, on the other hand, an expulsion opening for expelling solid-phase-rich cooling fluid (4);

[0039] at least one hollow disk mounted fixedly in the crystallization chamber in contact with the circulating stream of cooling fluid from the tapping orifice to the expulsion opening, said disk having, passing through it internally, a refrigerant fluid in the course of evaporating or some other cooling fluid at a lower temperature;

[0040] a set of sweeping arms which are mounted on a spindle which is driven in rotation by a geared motor unit, and which arms are arranged with respect to the disk(s) in such a way as to sweep its surface in contact with the cooling fluid and to expel the solid-phase-rich cooling fluid toward the expulsion opening.

[0041] According to an embodiment of the device according to the invention, the indirect heat-exchange means comprises a set of hollow disks which are arranged parallel to one another and spaced apart, and in that at least some of the sweeping arms, mounted fixedly on the spindle of the geared motor unit are angularly offset from one another and, from one disk to the next or from one side of a disk to its adjacent side, to force the cooling fluid to circulate within the crystallization chamber, the sweeping arms together thus constituting the withdrawing/discharging means for recycling the cooling fluid within the storage and regeneration compartment.

[0042] According to one embodiment, the device according to the invention comprises a number of indirect heat-exchange means associated with one and the same storage and regeneration compartment and distributed about said compartment, which runs concentrically around the sole other conditioning compartment.

[0043] The device according to the invention has the advantage of keeping the cooling fluid in motion throughout its circulation through the two compartments, storage and regeneration, and conditioning, respectively, particularly in the indirect heat-exchange means, thus avoiding any setting that carries the risk that the circulation will become blocked by the frozen fluid.

[0044] Another advantage is associated with the large amount of cooling fluid that can be stored in two-phase form in the melting equilibrium, with a view to supplying any cold-transfer circuit.

[0045] Other features and advantages of the invention also from the detailed description hereinafter, with reference to the drawings, are given by way of nonlimiting examples, in which:

[0046] FIG. 1 depicts a view in section of a storage, regeneration and conditioning device according to the invention;

[0047] FIG. 2 is a schematic and part view of the device, from above, of FIG. 1;

[0048] FIGS. 3 and 4 are views in section of the indirect heat-exchange means incorporated into the device according to the invention, in section perpendicular to the axis and along the axis of said means, respectively;

[0049] FIGS. 5 to 9 are details of FIGS. 3 and 4;

[0050] FIG. 10 is a view in section of another exemplary embodiment of a device according to the invention;

[0051] FIG. 11 is a view on AA of FIG. 10;

[0052] FIG. 12 depicts a detail of the indirect heat-exchange means of the device according to the invention;

[0053] FIG. 13 is an exploded section on XIII-XIII of FIG. 12.

[0054] FIG. 1 is a view in section of a storage, regeneration and conditioning device according to the invention. This device comprises a storage and regeneration compartment 2 containing a cooling fluid 4 in the two-phase state in melting/crystallization equilibrium. The device according to the invention also comprises an indirect heat-exchange means 6 for the exchange of heat between a refrigerant fluid and the cooling fluid 4 essentially in the liquid phase. This indirect heat-exchange means 6 is associated with the storage and regeneration compartment 2.

[0055] A circulation means 8 of the pump type depicted for example in FIG. 2 is provided to circulate the cooling fluid 4 tapped from the storage and regeneration compartment 2 in a heat-transfer circuit 10 comprising one or more heat exchangers 12. The heat-transfer circuit 10 opens downstream of the heat-exchange means 12 into the storage and regeneration compartment 12.

[0056] By way of an alternative not depicted in the figures, it is also possible to reinject the cooling fluid 4 downstream of the heat-exchange means 12 directly into the indirect heat-exchange means 6 if the return of the cooling fluid 4 is at a temperature higher than the crystallization temperature.

[0057] The heat transfer circuit 10 thus opens for example into the storage and regeneration compartment 2, via an opening 2a.

[0058] The volume into which the heat-transfer circuit 10 opens is preferably partially separated or demarcated from the remainder of the storage and regeneration compartment 2 and may in its lower part comprise gratings 14 able to contain the cooling fluid 4 in solid phase in said storage and regeneration compartment 2. The gratings 14, thus constituting a filter, may be omitted when the storage and regeneration compartment 2 is large enough to obtain good separation of the cooling fluid 4 in the liquid phase towards the bottom.

[0059] The storage and regeneration compartment 2 delimits a central separation region 2b including the lower part arranged, on the one hand, between the gratings 14 and, on the other hand, between two boundary walls 16 and 18. The first boundary wall 16 provides partial delineation between the storage and regeneration region 2b and the region comprising the indirect heat-exchange means 6. The second boundary wall 18 provides partial delineation between the storage and regeneration region 2b and another conditioning compartment 20 in the form of an ice slurry, of said cooling fluid 4. This second compartment 20 is connected to the heat-transfer circuit 10 via an opening 22 associated with the circulation means 8. The other conditioning compartment 20 is also supplied with cooling fluid 4 of the ice slurry type.

[0060] The device according to the invention also comprises a two-phase recycling and cooling circuit for recycling and cooling the cooling fluid 4 within the storage and regeneration compartment 2. This two-phase recycling and cooling circuit comprises at least one tapping point 24 at the lower part of said storage and regeneration compartment 2. The gratings 14 are spaced away from the corresponding side walls 2e to constitute flow corridors opening onto the tapping point or points 24, supplying the indirect heat-exchange means 6. The recycling and cooling circuit also incorporates the indirect heat-exchange means 6 and further comprises a means for withdrawing and discharging the cooling fluid 4. The cooling fluid 4 is thus drawn into the indirect heat-exchange means 6, as depicted for example in FIG. 4 by the arrows “A”.

[0061] The other conditioning compartment 20 and the indirect exchange means 6 are, for example, arranged one on each side of the central storage and regeneration region 2b, mainly constituting the storage and regeneration compartment 2 for the cooling fluid 4.

[0062] The other conditioning compartment 20 is supplied at an upper level with at least some of the solid-phase-rich cooling fluid 4 outside of the indirect heat-exchange means itself, and this is done using introduction means 72.

[0063] A complementary tapping point on the storage and regeneration compartment 2, this being at the lower part, associated with means 26 for injecting cooling fluid 4 in liquid phase into said other conditioning compartment 20 is also provided.

[0064] The cooling fluid 4 in liquid phase is thus conveyed to the other conditioning compartment 20 for example with the aid of a distribution tube 28 arranged more or less in its central part.

[0065] A mixing member 30 is also provided to collaborate with the other conditioning compartment 20 so as to mix the liquid and solid phases of the cooling fluid 4 which are contained in said other compartment 20. The device according to the invention also comprises a level detector 32 for determining the fill level of the other conditioning compartment 20 with the cooling fluid 4 in the form of ice slurry.

[0066] According to one exemplary embodiment, the device also comprises a measuring member 34 for determining the solid phase concentration of the cooling fluid 4 in the form of ice slurry in the other conditioning compartment 20. The measuring member 34 is for example produced with a temperature sensor, or an electrical conductivity or capacitive sensor or with means for measuring opacity, which is associated with appropriate analysis means, of the electronic or microprocessor type.

[0067] The circulation means 8 allows the cooling fluid 4 to be reinjected downstream of the heat exchanger or exchangers 12 of the heat-transfer circuit 10, for example into the storage and regeneration compartment 2, via an orifice 2a formed therein at a lower level.

[0068] According to an alternative form of embodiment of the device according to the invention, the circulation means 8 and the heat-transfer circuit 10 are also or solely connected to the indirect heat-exchange means 6 so that the cooling fluid 4 can be reinjected directly thereinto downstream of the heat exchanger or exchangers 12.

[0069] The indirect heat-exchange means 6 is depicted schematically more specifically in FIGS. 2, 3 and 4.

[0070] The indirect heat-exchange means 6 comprises a crystallization chamber 6a provided, on the one hand with at least one tapping orifice 6b for tapping of solid-phase-lean cooling fluid 4, communicating via the tapping orifices 24 with the storage and regeneration compartment 2 of the lower part and, on the other hand, with an expulsion opening 6c for expelling solid-phase-rich cooling fluid 4.

[0071] The indirect heat-exchange means 6 also comprises at least one hollow disk 40 mounted fixedly in the chamber 6a, in contact with the stream of cooling fluid 4 circulating from the tapping orifice 6b to the expulsion opening 6c. The hollow disk 40 has passing across it internally a refrigerant fluid in the course of evaporating, for example NH3. The hollow disk or disks 40 are supplied with this refrigerant fluid via a refrigeration unit 50 arranged for example beside the heat-exchange means 6. By way of an alternative according to the invention, the refrigerant fluid may be replaced by another cooling fluid, different from the one circulating in the heat-transfer circuit 10, but colder.

[0072] The indirect heat-exchange means 6 also comprises a set of sweeping arms 60 mounted on a spindle 62, which is driven in rotation by a geared motor unit 64. The sweeping arms 60 are arranged with respect to the hollow disk(s) 40 in such a way as to sweep their surface in contact with the cooling fluid 4 and to expel the enriched cooling fluid 4 in the process of being supercooled toward the expulsion opening 6c of the chamber 6a. Crystallization of the cooling fluid 4 thus occurs directly in the discharged and expelled stream. The expulsion of the cooling fluid 4 and more precisely the discharge of this cooling fluid 4 is depicted schematically by the arrows “R” as shown in FIGS. 4 and 3. The return of the cooling fluid 4 or of the ice slurry is downstream of the heat exchangers 12. The or each hollow disk 40 has a central passage 41 through which the spindle 62 passes. The cooling fluid 4 is thus drawn through the tapping openings 6b to then circulate from the passage or passages 41 to the periphery of each hollow disk 40, by a centrifugal effect.

[0073] One exemplary embodiment of a hollow disk 40 is depicted in FIGS. 12 and 13. The hollow disk 40 comprises, for example, two lateral plates 42 and an intermediate plate 43, each one provided with a central passage 41.

[0074] The intermediate plate 43, cut into serpentines 43a, is sandwiched and trapped closely and with sealing between the lateral plates 42. The serpentines 43a thus produce the circulation path for a refrigerant fluid, the circulation of which is depicted schematically for example by the arrows Fe and Fs in FIGS. 3 and 12. The arrows FE and FS correspond respectively to the inlet and outlet directions of the refrigerant fluid circulating in the hollow disk 40.

[0075] The indirect heat-exchange means 6 comprises, for example, a set of hollow disks 40 which are arranged parallel to one another and spaced apart. At least some of the sweeping arms 60 mounted fixedly on the spindle 62 of the geared motor unit 64 are offset angularly from one another, from one disk to the next, or from one side of a disk to its adjacent side, to force the cooling fluid 4 to circulate within the crystallization chamber 6a. The set of sweeping arms 60 as a whole thus constitutes intake and discharge means for recycling the cooling fluid 4 within the storage and regeneration compartment 2. The rotation of the sweeping arms 60 is depicted schematically by the arrow “V” in FIGS. 3 and 4.

[0076] Advantageously, the expulsion opening 6c is shaped, positioned and orientated in such a way as to expel the solid-phase-rich cooling fluid 4 to the other conditioning compartment 20, thus constituting means of introduction thereinto. The sweeping arms 60 may adopt different shapes depicted by way of example in FIGS. 5 to 9. The sweeping arms 60 may thus be curved as depicted in FIGS. 6 and 8, or elbowed as depicted in FIGS. 5 and 7. The number of sweeping arms 60 for sweeping the surface of a hollow disk may also vary. Specifically, it is possible, as depicted in FIGS. 5 and 6, to sweep the surface of a hollow disk 40 using two sweeping arms 60 or, for example, using four sweeping arms 60, as is depicted in FIGS. 7 and 8. This list is not in any way limiting. It is also possible to add more sweeping arms 60, to sweep the same surface. The term “sweeping” is to be understood in the broadest sense, that is to say also as encompassing arms 60 encouraging disruption of the supercooled boundary layer near the hollow disk 40. A supercooled boundary layer is to be understood as meaning the film which cools upon contact with the hollow disk 40. The term “sweeping” does not necessarily means to say that there is mechanical contact between the arms and the surface of the hollow disk 40, for example via brushes 41. The term “supercooling” is to be understood as meaning cooling to a temperature lower than the usual freezing temperature.

[0077] FIG. 9 shows an exemplary embodiment in which the adjacent sweeping arms 60 are angularly offset from one another.

[0078] According to the embodiment (cf. FIG. 1), the expulsion opening 6c is positioned and orientated in such a way as to expel the solid-phase-rich cooling fluid 4 into the storage and regeneration compartment 2, and more specifically into the central region 2b at an upper level. The introduction means 72 then extend at an upper level into said storage and regeneration compartment 2. They comprise moving blades 70 designed to push the cooling fluid 4 toward and into the conditioning compartment 20. The moving blades 70 are advantageously mounted on a chain or a belt driven by a geared motor unit 74.

[0079] According to another exemplary embodiment of the device according to the invention, depicted in FIGS. 10 and 11, the moving blades 170 are mounted on horizontal arms 172, themselves fixed on a vertical spindle 174 driven by a geared motor unit 176. The moving blades 170 are, for example, orientable with respect to their horizontal mounting arms 172, as depicted schematically in FIG. 11 by the arrows “W”.

[0080] In this exemplary embodiment, the device according to the invention comprises a plurality of indirect heat-exchange means 6 (just one of which is depicted in FIG. 11), which are associated with one and the same storage and regeneration compartment 2. The indirect heat-exchange means 6 are distributed about the storage and regeneration compartment, which itself runs concentrically around the sole other conditioning compartment 20.

[0081] The wall 20a delimiting the other conditioning compartment 20 has a preferred height that does not substantially alter the solid-phase cooling fluid 4 supply from the blades 170. A mixing member 30 immersed in the other conditioning compartment 20 is, for example, mounted on the spindle 174 and rotates therewith. For installations with high refrigerating capacity, that is to say devices of significant size, it is possible to provide, at the end of each horizontal arm 172, a support wheel 200 running along a rim 201 formed in the upper part on the wall 2c demarcating the storage and generation compartment 2.

[0082] The operation of the device depicted in FIGS. 10 and 11 is, for the remainder, identical to that of the device depicted in FIG. 1. The refrigeration source 50 may be placed beside, underneath, or completely independently of the indirect exchange means 6. The admission of cooling fluid 4 in liquid phase into the indirect heat-exchange means 6 or, more specifically, into the chamber 6a is via ducts 6d opening into the storage and regeneration compartment 2.

[0083] The device according to the invention makes it possible to employ a method for storing and regenerating a cooling fluid in two-phase form and intended to supply one or more heat exchangers 12. This method makes it possible to illustrate the operation of such a device according to the invention. We therefore have a cooling fluid 4 comprising a solid phase in melting/crystallization equilibrium with a liquid phase, and said cooling fluid 4 is circulated through the circuit comprising the heat exchangers 12 and into a storage and regeneration compartment 2 associated with an indirect heat-exchange means 6. The cooling fluid 4 is constantly stored in the storage and regeneration compartment, thus allowing the liquid phase and the solid phase of said fluid to separate. Tapping the cooling fluid 4 from said storage and regeneration compartment 2, essentially in the liquid phase, and circulating it through the indirect heat-exchange means 6 allow said fluid to be converted to a solid phase, which is broken down into microcrystals. The latter, rich in microcrystals, is then reinjected into the storage and regeneration compartment 2.

[0084] In accordance with the invention, some of the cooling fluid 4 rich in microcrystals or solid phase is separated off and stored in the other conditioning compartment 20 in the form of ice slurry. Some of the cooling fluid 4 in liquid phase, or lean in solid phase, taken from the storage and regeneration compartment 2 is then injected into said other conditioning compartment 20 so as to mix the solid and liquid phases of the cooling fluid 4 in said other conditioning compartment 20. The ice slurry mixed in the other conditioning compartment 20 is thus ready to be drawn or pumped into the heat-transfer circuit 10. The cooling fluid 4 or ice slurry is returned downstream of the heat exchangers 12 either directly into the crystallization chamber 6a or into the storage and regeneration compartment 2 at a lower level.

[0085] According to the invention, the method also consists in altering the amount of solid-phase-lean cooling fluid 4 injected into the other conditioning compartment 20. The method according to the invention also consists in determining, in the conditioning compartment 20, the solid-phase concentration and in altering this concentration as necessary by acting on the amount of solid-phase-lean cooling fluid 4 injected into the other conditioning compartment 20.

[0086] According to the method according to the invention, it is also possible to determine the fill level of the other conditioning compartment 20 with cooling fluid of the ice slurry type, and to use the result of this determination to act on the angle of incidence of the blades 170 or the speed at which the blades 70, 170 move. It is also possible to accelerate, slow down or if necessary interrupt the various operations of said method and, in particular, operations (f), (g) and (h). It is thus possible to influence the orientation of the blades 170 in order to alter the amount of solid phase cooling fluid 4 reinjected into the other conditioning compartment 20.

[0087] The amount of cooling fluid 4 in the liquid phase reinjected into the other conditioning compartment 20 is governed by the measurement member 34 determining the microcrystals concentration.

[0088] According to this method, and by virtue of the device employing this method, it is thus possible to produce refrigeration sources able to supply large entities or large units, or even whole districts, for air conditioning purposes.

[0089] The movement of the microcrystal-enriched cooling fluid 4 encouraged as appropriate by the introduction means of the blades 70, 170 type, generates a movement in the reverse direction of the liquid-phase cooling fluid 4 in the bottom of the storage and regeneration compartment 2. This movement is advantageously toward the crystallization chamber 6a. The movement of the liquid-phase cooling fluid 4 toward the crystallization chamber 6a is thus encouraged at the same time as the movement of the microcrystal-rich cooling fluid toward the other conditioning compartment 20. The blades 70 and 170 constantly keep the crystal-rich or solid-phase upper part in the pasty state, and prevent the crystals from setting en masse. This device is necessary in large-capacity units, for example those used discontinuously.

Claims

1. A device for storing and regenerating a cooling fluid (4) in two-phase form, intended to circulate through a heat-transfer circuit (10) comprising one or several heat exchangers (12), said device comprising:

a storage and regeneration compartment (2) for storing and regenerating the cooling fluid (4) in the two-phase state, in melting equilibrium;

at least one indirect heat-exchange means (6) for the exchange of heat between a refrigerant fluid or another cooling fluid and the cooling fluid (4), in liquid phase, associated with said compartments (2);

a circulation means (8) of the pump type, for circulating the cooling fluid (4), drawn from said compartment (2), in the heat-exchange circuit (10) and for reinjecting it into said compartment;

a two-phase recycling and cooling circuit for recycling and cooling the cooling fluid (4), within said compartment, comprising a tapping point (24) at the lower part of said compartment, said recycling circuit incorporating the indirect heat-exchange means and comprising a means for withdrawing/discharging the cooling fluid (4); characterized in that it comprises:

another compartment for conditioning in the form of ice slurry, connected to the heat-transfer circuit (10), itself supplied with cooling fluid (4) of the ice slurry type;

means for introducing some of the cooling fluid (4) enriched in solid phase, outside of the indirect heat-exchange means, itself into said other compartment, at a higher level;

a complementary tapping point (24) on the storage and regeneration compartment (2), in the lower part, and injection means (26, 28) for injecting cooling fluid (4), in liquid phase, into said other compartment;

and a mixing member, collaborating with said other compartment, for mixing the liquid and solid phases of the cooling fluid (4).

2. The device as claimed in claim 1, characterized in that it comprises a level detector (32) making it possible to determine the fill level of the conditioning compartment (20) by the cooling fluid (4) in the form of ice slurry.

3. The device as claimed in claim 1 or 2, characterized in that it comprises a measuring member (34) for determining the solid-phase concentration of the cooling fluid (4), in the form of ice slurry, in the conditioning compartment (20).

4. The device as claimed in claim 1 any one of claims 1 to 3, characterized in that the circulation means (8) is designed to reinject, downstream of the heat exchanger or exchangers (12) of the heat and transfer circuit (10), the cooling fluid (4) into the storage and regeneration compartment (2), using an orifice (2a) formed in the latter at a lower level.

5. The device as claimed in claim 1 any one of claims 1 to 3, characterized in that the circulation means (8) is connected to the indirect heat-exchange means (6) so that the cooling fluid (4) can be reinjected directly thereinto downstream of the heat exchanger or exchangers (12) of the heat transfer circuit (10).

6. (Currently Amended) The device as claimed in claim 1 any one of claims 1 to 5, characterized in that the indirect heat-exchange means (6) comprises:

a crystallization chamber (6a) provided, on the one hand, with at least one tapping orifice (6b) for solid-phase-lean cooling fluid (4), communicating with the storage and regeneration compartment (2) in the lower part and, on the other hand, an expulsion opening (6c) for expelling solid-phase-rich cooling fluid (4);

at least one hollow disk (40) mounted fixedly in the crystallization chamber (6a) in contact with the circulating stream of cooling fluid (4) from the tapping orifice (6b) to the expulsion opening (6c), said disc having, passing through it internally, a refrigerant fluid in the course of evaporating or some other cooling fluid at a lower temperature;

a set of seeping arms (60) which are mounted on a spindle (62) which is driven in rotation by a geared motor unit (64), and which arms are arranged with respect to the disk(s) (40) in such a way as to sweep its surface in contact with the cooling fluid (4) and to expel the solid-phase-rich cooling fluid (4) toward the expulsion opening (6c).

7. The device as claimed in claim 6, characterized in that the indirect heat-exchange means (6) comprises a set of hollow disks (40) which are arranged parallel to one another and spaced apart, and in that at least some of the sweeping arms (60), mounting fixedly on the spindle (62) of the geared motor unit (64) are angularly offset from one another and, from one disc (40) to the next or from one side of the disk (40) to its adjacent side, to force the cooling fluid (4) to circulate within the crystallization chamber (6a), the sweeping arms (60) together thus constituting the withdrawing/discharging means for recycling the cooling fluid (4) within the storage and regeneration compartment (2).

8. The device as claimed in claim 7, characterized in that the expulsion opening (6c) is shaped, positioned and orientated in such a way as to expel the solid-phase-rich cooling fluid (4) toward the other conditioning compartment (20), thus constituting the means of introduction thereinto.

9. The device as claimed in claim 7, characterized in that the expulsion opening (6c) is positioned and orientated in such a way as to expel the solid-phase-rich cooling fluid (4) into the storage and regeneration compartment (2) at a higher level, and in that the introduction means extend at a higher level into said storage and regeneration compartment (2) and compose moving blades (70, 170) designed to push the cooling fluid (4) toward and into the other conditioning compartment (20).

10. The device as claimed in claim 9, characterized in that the blades (170) are mounted on a chain or a belt (72) driven by a geared motor unit (74).

11. The device as claimed in claim 9, characterized in that the blades (170) are mounted on horizontal arms (172) themselves fixed to a vertical spindle (174) driven by a geared motor unit (176).

12. The device as claimed in claim 11, characterized in that the blades (170) can be orientated with respect to the horizontal arms (172) supporting them.

13. The device as claimed in claim 1 any one of claims 1 to 12, characterized in that it comprises a number of indirect heat-exchange means (6) associated with one and the same storage and regeneration compartment (2) and distributed about the said compartment, which runs concentrically around the sole other conditioning compartment (20).

14. A method for storing and regenerating cooling fluid (4) in two-phase form, intended to supply one or more heat exchangers (12), consisting in:

(a) having a cooling fluid (4) comprising a solid phase in melting equilibrium with a liquid phase;

(b) circulating the cooling fluid (4) through a circuit comprising the heat exchanger or exchangers (12) and through a storage and regeneration compartment (2) associated with an indirect heat-exchange means (6);

(c) storing the cooling fluid (4) in the compartment (2) to allow the liquid phase and solid phase of said fluid to separate;

(d) tapping from said compartment (2) the cooling fluid (4) essentially in the liquid phase and circulating it through the indirect heat-exchange means (6) so as to convert it to a solid phase, which is broken down into microcrystals;

(e) reinjecting the cooling fluid (4) rich in microcrystals leaving the indirect heat-exchange means (6) into said compartment (2); characterized in that it consists in:

(f) separating and storing some of the solid-phase-rich cooling fluid (4) in another conditioning compartment (20) in the form of ice slurry;

(g) injecting into said other compartment some of the liquid-phase or solid-phase-lean cooling fluid (4) tapped from the storage and regeneration compartment (2);

(h) mixing the solid and liquid phases of the cooling fluid (4) in said other compartment (20);

(i) using the cooling fluid (4) obtained in (h) to carry out step (a) by tapping cooling fluid (4) conditioned in the form of ice slurry from said other compartment (20) and reinjecting it, downstream of the heat exchanger or exchangers (12) of the heat-transfer circuit (10) into the storage and regeneration compartment (2), and or/for example at the inlet to the indirect heat-exchange means.

15. The method as claimed in claim 14, characterized in that it consists in altering the amount of solid phase-lean cooling fluid (4) injected into the other conditioning compartment (20).

16. The method as claimed in claim 14, characterized in that it consists in determining, in the other conditioning compartment (20), the solid phase concentration and in altering this concentration as appropriate by altering the amount of solid-phase-lean cooling fluid injected into the other conditioning compartment acting in accordance with claim 15.

17. The method as claimed in claim 14 any one of claims 14 to 16, characterized in that it consists in:

determining the fill level of the conditioning compartment (20) with cooling fluid (4) of the ice slurry type;

and using the result of this determination to accelerate, direct, slow down or, as appropriate, interrupt the operations in accordance with (f), (g) and (h);

or alter the inclination of the blades (70, 170).