Refrigeration unit having an accumulator, refrigeration system and method for controlling a refrigeration unit having an accumulator

Abstract

Disclosed is a refrigeration unit having an accumulator, a refrigeration system and a method for controlling a refrigeration unit having an accumulator, wherein the refrigeration unit has a refrigeration chamber for receiving and storing goods to be refrigerated, an accumulator having an accumulator holder in which a storage medium is accommodated, a heat exchanger, a controller and a coolant line arrangement which can be connected to a coolant supply network via connections. The coolant line arrangement is guided through the accumulator holder, and the heat exchanger is thermally coupled to the storage medium accommodated in the accumulator holder. A coolant control device is arranged in the flow pipe of the coolant arrangement, wherein the storage medium accommodated in the accumulator holder is cooled via a coolant in the coolant line arrangement, and the heat exchanger is cooled via the storage medium.

Claims

1. A refrigeration unit comprising a refrigerating space for reception and storage of items to be refrigerated, a storage device for storing a storage medium with a storage device container in which a storage medium is received, a heat exchanger, a controller and a coolant line arrangement connectible by connections with a coolant supply network, wherein the coolant line arrangement is led through the storage device container, the heat exchanger is arranged at an outside of the storage device and is thermally coupled with the storage medium received in the storage device container, a coolant regulating device, which regulates a feed of a coolant from the coolant supply network to the storage device, is arranged in a forward run of the coolant line arrangement, the coolant regulating device is a speed-regulated pump, the storage device container at least in a section comprises a thermally conductive material and has an insulation, the insulation completely surrounds the storage device apart from a section by which the storage device is connected with the heat exchanger, and the heat exchanger has cooling ribs, wherein the heat exchanger is coupled by at least one thermally conductive section of the storage device container with the storage medium received in the storage device container, and wherein a second coolant line arrangement is led through the storage device container and connected with the heat exchanger.

2. The refrigeration unit according to claim 1, wherein a speed-regulated pump is arranged in a forward run of the second coolant line arrangement.

3. The refrigeration unit according to claim 2, further comprising at least one speed-regulated fan.

4. The refrigeration unit according to claim 2, wherein the refrigeration unit has refrigerated shelving.

5. The refrigeration unit according to claim 1, further comprising at least one speed-regulated fan.

6. The refrigeration unit according to claim 2, wherein the refrigeration unit has refrigerated shelving.

7. The refrigeration unit according to claim 1, wherein the refrigeration unit has refrigerated shelving.

8. A refrigeration system comprising at least one refrigeration unit as claimed in claim 1 and a cold generator, wherein a coolant is fed by a central coolant line arrangement to the at least one refrigeration unit via a forward run and is conducted away via a return run and the cold generator brings the coolant to a settable temperature, wherein the feed of coolant for discharge of the storage device is regulated by the controller of the refrigeration unit via the coolant regulating device in the forward run of the coolant line arrangement and/or the circulation of air over at least one heat exchanger for cooling the refrigerating space is regulated by the controller of the refrigeration unit via an at least one fan and/or the feed of coolant to at least one heat exchanger is regulated by the controller of the refrigeration unit in dependence on a charge state of the storage device and/or an operating state of the cold generator via the speed-regulated pump in a forward run of a second coolant line arrangement.

9. A method of controlling a refrigeration unit as claimed in claim 1, said refrigeration unit comprising a refrigerating space for reception and storage of items to be refrigerated, a storage device for storing a storage medium with a storage device container in which a storage medium is received, a heat exchanger, a controller and a first coolant line arrangement which is connectible with a coolant supply network by connections, wherein the first coolant line arrangement is led through the storage device container, the heat exchanger is thermally coupled with the storage medium received in the storage device container and a coolant regulating device which regulates a feed of a coolant from the coolant supply network to the storage device, is arranged in a forward run of the first coolant line arrangement and wherein the storage medium received in the storage device container is cooled by a coolant in the first coolant line arrangement and the heat exchanger is cooled by the storage medium.

10. The method according to claim 9, wherein a second coolant line arrangement is led through the storage device container and connected with the heat exchanger and a speed-regulated pump is arranged in a forward run of the second coolant line arrangement, wherein discharge of the storage device is carried out by the coolant regulating device in the forward run of the first coolant line arrangement and/or thawing of the storage device and feed of coolant to at least one heat exchanger are carried out by the speed-regulated pump in the forward run of the second coolant line arrangement and/or circulation of air for cooling the refrigerating space is carried out by at least one speed-regulated fan.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the drawings:

(2) FIG. 1 snows a schematic illustration of a refrigeration unit;

(3) FIG. 2 shows a further schematic illustration of a refrigeration unit;

(4) FIG. 3 snows yet a further schematic illustration of a refrigeration unit;

(5) FIG. 4 shows a still further schematic illustration of a refrigeration unit; and

(6) FIG. 5 shows a schematic illustration of a storage device with a directly coupled heat exchanger.

(7) In the drawings, parts provided with the same reference numerals substantially correspond with one another insofar as nothing to the contrary is indicated. In addition, description of components not essential to understanding the technical teaching disclosed herein has been dispensed with.

DETAILED DESCRIPTION OF THE INVENTION

(8) FIG. 1 shows a schematic illustration of a refrigeration unit 10. The refrigeration unit 10 can be constructed as, for example, refrigerated shelving 60 and be part of a refrigerating system with a plurality of refrigeration units 10. A cold generating device, for example a heat pump, is provided in the refrigerating system and cools a coolant conducted in a coolant supply network. The coolant supply network has a forward run 50 and a return run 52. Cooled coolant is fed to the refrigeration units 10 by way of the forward run 50. The coolant heated and returned by the refrigeration units 10 is fed back by way of the return run 52 to the cold generator, which brings the coolant to a specific temperature.

(9) The refrigeration unit 10 comprises a housing 12. The housing 12 encloses the equipment items of the refrigeration unit 10 and a refrigerating space 14. A closure device which can free and close the schematically indicated refrigerating space 14 can be arranged in the housing 12. Such a device is, for example, known as a roller blind in the case of refrigerated shelves.

(10) The refrigeration unit 10 comprises a storage device 15 into which a first line arrangement is led. The first line arrangement is connected by way of the forward run 28 thereof with the forward run 50 of the coolant supply network. The coolant line arrangement is led out of the storage device 15 and the refrigeration unit 10 by way of the return run 30 and is connected with the return run 52 of the coolant supply network. A coolant regulating device 22 is arranged in the forward run 28. The coolant regulating device 22 can be configured as, for example, a valve or as a speed-regulated pump 38 (see FIG. 2). The coolant regulating device 22 and the speed-regulated pump 38 therefore regulate the feed of coolant from the coolant supply network to the storage device 15.

(11) The storage device 15 comprises a housing 16. The housing 16 is surrounded by an insulation 18 which substantially thermally insulates the storage device 15 from the space surrounding it within the refrigeration unit 10. A cooling medium is received in the storage device 15. The cooling medium can be provided by, for example, water. When coolant is fed by way of the coolant supply network via the forward run 28 the cooling medium in the storage device 15 is cooled. A phase conversion, for example, takes place, so that the storage medium transfers from a liquid phase to a solid phase.

(12) In addition, a part of a second coolant line arrangement is led into the storage device 15. The second coolant line arrangement is additionally coupled with a heat exchanger 24, a speed regulated pump 32 being provided in the forward run 34 of the second coolant line arrangement. A coolant is circulated in the separate coolant circuit of the second coolant line arrangement by way of the pump 32. The coolant in the second coolant circuit is cooled by way of the storage device 15 and fed by way of the pump 32 to the heat exchanger 24. Air is fed across the heat exchanger 24 by way of a fan 26, which is similarly speed-regulated, so that cooling of the air takes place. The cooled air is conducted in the product compartment or refrigerating space 14 and/or circulated in the product compartment or refrigerating space 14.

(13) A controller 20 regulates the coolant regulating device 22, the pump 32 and the fan 36. In addition, the controller 20 can take over still further tasks. For example, the controller 20 is coupled with the temperature detection devices which detect the temperature in the refrigerating space 14, in the forward run 34 and return run 36 of the second coolant line arrangement and in the forward run 28 and return run 30 of the first coolant line arrangement. Further, the temperature in the storage device 15 can be detected at various places by way of temperature detection devices. A refrigeration requirement for products in the refrigerating space 14 can be determined by the controller 20 through the temperature detection devices. The controller 20 regulates the pump 32 as a function of the determined refrigeration requirement, so that a greater quantity of coolant can be fed to the heat exchanger 24. In the case of an additional increase in the rotational speed of the fan 26 a greater air flow is circulated, in which case the circulated air is not heated so strongly, which additionally serves for rapid cooling. The cooling of the coolant in the second coolant circuit takes place by way of the storage medium received in the storage device 15. When coolant is fed from the coolant supply network, cooling of the storage medium in the storage device 15 takes place substantially from the inside to the outside. In that case, a phase conversion of the storage medium may occur. For that purpose, the line sections of the first coolant line arrangement or the forward run 26 and return run 30 are laid appropriately in the storage device 15 or in the housing 16. The line sections of the second coolant line arrangement, particularly the line sections of the forward run 34 and the return run 36, extending within the housing 16 of the storage device 16 are so arranged that coding of the coolant conducted therein takes place in such a way that thawing of the storage device 15 or a phase conversion of the storage medium from solid to liquid takes place from the outside to the inside. In addition, the latent heat of the storage medium can be used for discharging and charging the storage device 15 even without a phase conversion.

(14) In operation of the refrigeration unit 10 discharge of the storage device 15 takes place in dependence on the feed of coolant by way of the coolant supply line in the forward run 50 via the coolant regulating device 22 or the pump 38. If the storage device is completely discharged, the feed of coolant by way of the forward run 50 into the storage device 15 can be prevented by way of the coolant regulating device 22 or the pump 38. Cooling of the refrigerating space 14 is regulated by way of the pump 32, for which purpose the amount of coolant in the second coolant circuit with the second coolant line arrangement to the heat exchanger 24 is regulated. If the refrigerating space 14 or the products stored therein has or have an increased need for refrigeration and the controller ascertains rapid thawing of the storage device 15 then the coolant regulating device 22 can provide the feed of coolant from the forward run 50 and regulate the quantity of coolant.

(15) A pump 38, in particular, enables stepless setting of the conveyed quantity of coolant. In addition, the fan 26 determines the amount of circulated air, in which case at higher flow rates of the air this is less strongly heated than in the case of smaller air flows.

(16) If the storage device 15 is discharged to a certain extent and/or the coolant feed via the forward run 50 of the coolant supply network is no longer provided an autonomous operation of the refrigeration unit 10 can also take place. The storage device 15 in that case serves as a cold generator and provides cooling of the coolant conducted in the second coolant circuit. The design of the storage device 15 with respect to the dimensioning of the refrigerating space 14 and the maximum items able to be accepted in the refrigerating space 14 can be as desired. The larger the storage device 15 in relation to the refrigerating space 14 and the products stored therein the faster and/or longer can cooling of the items or the refrigerating space 14 take place. A refrigeration unit 10, which is configured as refrigerated shelving 60, with a roller blind can, preferably be operated at night solely by the ‘coldness’ provided by way of the storage device 15, in which case the coolant supply network does not have to be placed in operation for that purpose. In the case of heat pumps as cold generator, this has the advantage that the cycles of the heat pumps, i.e. the intervals between switching on and switching off, are extended,

(17) In addition, in the case of a refrigerating system with a plurality of refrigeration units 10 an emergency cooling can be provided in the event of failure of the cold generator. The refrigeration units 10 of the refrigerating system, the storage devices 15 of which have a minimum discharge state, can bring the temperature of the coolant in the supply network substantially to a defined temperature so that at least one further refrigeration unit 10 of the refrigerating system is appropriately cooled and/or the storage device 15 thereof discharged.

(18) FIG. 2 shows a further, schematic illustration of the refrigeration unit 10, in which case the coolant regulating device 22 is constructed as a speed-regulated pump 38 and arranged in the forward run 28, instead of a pump 38, it is also possible in other embodiments (not illustrated) for valves to be provided.

(19) Moreover, the refrigeration units 10 shown in FIGS. 1 to 4 comprise further components such as valves, insulations, assembly and connecting elements and control components, which are not illustrated.

(20) FIG. 3 shows yet a further, schematic illustration of refrigeration unit 10 with a heat exchanger 24 connected directly with the storage device 15. The housing 16 of the storage device 15 consists of a thermally conductive material and comprises an insulation 18 which insulates the storage device 15 apart from a section 40 by way of which the storage device 15 is connected with the heat exchanger 24. In addition, it is also possible for only the section 40 to consist of a thermally conductive material. The rest of the housing 16 can consist of different materials which have, for example, thermally insulating characteristics. In the case of the refrigeration unit 10 of FIG. 3, cooling or discharging of the storage device 15 equally takes place by way of a coolant fed by way of the forward run 50 of a coolant supply network.

(21) The feed of coolant by way of the supply network is carried out via the pump 32. The controller 20 of the refrigeration unit 10 regulates the amount of coolant, which is conducted from the coolant supply network into the storage device 15 in order to discharge the storage device 15, by way of the rotational speed of the pump 32. In particular, in the case of a relatively low coolant temperature a rapid discharge of the storage device 15 can be achieved by a high rotational speed. Moreover, it is also possible to throttle the rotational speed of the pump 32 in order to provide a lower rate of coolant feed, which leads to slower discharging. Equally, a lower rotational speed of the pump 32 can be set by way of the controller 20 when the coolant has a temperature which is too low. It is thereby ensured that defined discharging of the storage device 15 takes place. It is to be noted, in particular, that in the storage device 15 a discharge, for example a phase conversion of the storage medium from liquid to solid, takes place from the inside to the outside. In order to prevent direct coupling of the heat exchanger 24 with the coolant conducted in the first coolant line arrangement the forward run 28 and return run 30 are, in particular, arranged at a spacing from the heat exchanger 24.

(22) In the case of a conventional cooling system for refrigerated shelves of the prior art with a product room temperature of 4° C. then, for example, a coolant is provided from a central supply line. This coolant has a temperature of −2° C. Due to the low temperature of the coolant relatively strong icing of the heat exchanger can therefore occur in a short time. In the case of the refrigerating systems described herein there is no feed of coolant from a central supply line to the heat exchangers 24. Coolant of a second coolant circuit in the refrigeration unit, which is coupled with a storage device 15, is fed to the heat exchangers 24, or the heat exchangers 24 are cooled directly by way of a storage device 15. The heat exchangers 24 in the case of refrigerated shelving 60 with a product room temperature of 4° C. thus have no regions which are cooled to an excessive extent. For that purpose, the coolant of a second coolant circuit can have a temperature of, tier example, 2° C. in the forward run.

(23) In the case of refrigerating systems of the prior art very low forward run temperatures of the coolant are accordingly set, since the coolant has to be supplied over, in part, lengthy routes to remote refrigerated shelves as well and the coolant temperature increases along the route. In order to ensure, for example, a coolant temperature of 0° C. at a remote refrigerated shelf of a refrigerating system of the prior art the coolant temperature at a first refrigerated shelf had to be −4° C. These relatively large temperature differences have led to remote refrigeration units being less strongly cooled. This can also have the consequence that heat exchangers of refrigerated shelves which do not have a large spacing from a cold generator strongly ice up in a relatively short time. The variants described herein do not have these problems, since the heat exchangers 24 are not directly coupled with the coolant of the supply network. In addition, in the case of very low coolant temperatures in the coolant supply network, cooling of several refrigeration units 10 with the same temperature can take place. Moreover, icing, for example of the storage medium in the storage device container, offers the possibility of cooling the refrigerating space 14 over a lengthy period time without coolant having to be supplied from outside.

(24) In addition, in the case of the embodiment according to FIG. 3 a homogenous cooling of the heat exchanger 24 over the entire length thereof and, in particular, over the entire contact area thereof is achieved by the thermally conductive housing 16 of the storage device 15.

(25) FIG. 4 shows yet a further schematic illustration of a refrigeration unit 10, wherein the embodiment of FIG. 4 differs from the embodiment of FIG. 3 in that in general a coolant regulating device 22 is arranged in the forward run 28 instead of a speed-regulated pump 32. The coolant regulating device 22 can be, for example, a valve.

(26) FIG. 5 shows a schematic illustration of a storage device 15 with a heat exchanger 24 coupled therewith. The housing 16 has a form which is wider in upward direction. The receiving space for the storage medium 44 is not completely filled with a storage medium 44, 45, but has a compensating region 46. The compensating region 46 serves for reception of the storage medium 44, 45 after expansion due to a phase change. The trapezium-shaped form of the storage device 15 in cross-section equally serves for defined expansion of the storage medium 44, 45 after a phase conversion.

(27) FIG. 5 shows a schematic sectional view of the storage device 15 and the heat exchanger 24. The storage device 15 can similarly have trapezium-shaped side walls in longitudinal direction.

(28) The heat exchanger 24 is arranged at the lefthand side of the housing 16 over a section 40. The heat exchanger 24 consists of a thermally conductive material, preferably the same thermally conductive material as the housing 16 of the storage device 15 or the section 40 of the housing 16. In further forms of embodiment, the heat exchanger 24 can also be constructed directly at the housing 16 of the storage device 15 and produced integrally therewith. In still further forms of embodiment a surface of the heat exchanger 24 forms a side wall of the housing 16 of the storage device 15. The remaining parts of the housing 16 can then be made of other materials and connected with the section 40. In addition, the storage device 15 comprises an insulation 18. The insulation 18 completely surrounds the storage device 15 apart from the section 40, so that there is substantially no heat transfer between the storage device 15 and the space surrounding it. The insulation 18 can be formed by, for example, foam materials.

(29) Moreover, the insulation 18 can consist of a layer composite of several layers of different materials.

(30) Coolant lines 48 of the forward run 28 and return run 30 of the first coolant line arrangement and/or coolant lines 48 of the forward run 34 and return run 36 of the second coolant line arrangement are accommodated in the interior of the storage device 15. Flowing through the coolant lines 48 is, for example, the coolant provided by way of a coolant supply network.

(31) The illustration of FIG. 5 is schematic. The coolant lines 48 can therefore also be lines of the forward run 34 and return run 36 of the second coolant line arrangement. Equally, the number of coolant lines 48 is merely exemplifying. The coolant lines 48 are preferably laid in the housing 16 in such a way that they are not in direct contact with the side walls of the storage device 15. The arrangement of the coolant lines 48 is, in particular, selected so that a defined discharge of the storage device 15 by coolant feed from the coolant supply network takes place from the inside to the outside and thawing takes place through supply of heat via a further coolant or via the heat exchanger 24 directly from the outside to the inside.

(32) The discharge from the inside to the outside is illustrated schematically in FIG. 4 by the frozen sections of the storage medium 45. In that case, the storage medium 45 freezes firstly at the coolant lines 48, which have a homogenous thermal conductivity at least in the sections in which they are guided within the storage device 15.

(33) The housing 16 of the storage device 15 has additional connections for the coolant lines 48. In further forms of embodiment, the storage device container or a storage device container together with a heat exchanger 24 is a subassembly able to be subsequently installed in a refrigeration unit 10. This means that coolant lines 48 are already arranged within the storage device 15 and a storage medium 44 is provided in the storage device 15. Coupling to a forward run 28 and a return run 30 of a first coolant line arrangement can then be undertaken by way of appropriately defined connections. In addition, coupling with a second coolant line arrangement can be effected by way of further, optionally provided connections for a forward run 34 and return run 36.

(34) It is thereby possible, in particular, to interrupt a coolant circuit of an existing refrigeration unit and arrange the storage device 15. The storage device 15 then provides a separation for an internal circuit of the refrigeration unit from an external circuit of a coolant supply network. However, there is additionally a thermal coupling of the two coolant circuits and a storage of ‘coldness’ is provided. Filling of the coolant circuits, particularly of a thus-formed internal coolant circuit for the refrigeration unit, can be undertaken subsequently.

REFERENCE NUMERAL LIST

(35) 10 refrigeration unit

(36) 12 housing

(37) 14 refrigerating space

(38) 15 storage device

(39) 16 housing

(40) 18 insulation

(41) 20 controller

(42) 22 coolant regulating device

(43) 24 heat exchanger

(44) 26 fan

(45) 28 forward run

(46) 30 return run

(47) 32 pump

(48) 34 forward run

(49) 36 return run

(50) 38 pump

(51) 40 section

(52) 42 cooling rib

(53) 44 storage medium

(54) 45 storage medium

(55) 46 compensating region

(56) 48 coolant line

(57) 50 forward run

(58) 52 return run

(59) 60 refrigerated shelving