Refrigerated cabinet with integrated hydraulic control and cooling system Description A refrigerated cabinet with built-in hydraulic regulation and a refrigerating system are described, wherein the refrigerated cabinet comprises an internal refrigerant circuit and connections for connection to a central refrigerant conduction system.
The refrigeration system comprises at least one refrigerated cabinet, which is connected to a cold generator by means of a refrigerant conduction system.
A refrigerated cabinet of this type is cooled by means of a refrigerant which is made available by an external cold generator.
As refrigerants, for example, water- based media such as, for example, brine, can be admitted.
Refrigerated cabinets of this type are particularly employed in the retail food trade, wherein said refrigerated cabinets are configured in the form of refrigerated shelves, cold stores, chiller cabinets or freezer cabinets.
Various devices can be employed as cold generators, such as, for example, a heat pump or a central cooling installation having heat exchangers and ventilators.
Prior art In the prior art, refrigerated cabinets of this type are connected to the cold generator via the pipe systems of a refrigerant conduction system which, in some cases, are extensively branched.
On the grounds of, in some cases, long line — sections, and depending upon the location of the respective refrigerated cabinet in the pipe system, a rise in the temperature of the refrigerant occurs, together with a drop in pressure.
Cooling systems from the prior art therefore feature disadvantages with respect to hydraulic equalization.
These disadvantages are overcome, wherein the refrigerant is delivered by the cold generator at a lower temperature than that which is actually required, such that even remote refrigerated cabinets can be operated at a corresponding temperature.
Moreover, in the pipe system of the refrigerant delivery system, it is necessary to provide conveyor devices, such as pumps, which deliver the refrigerant even to remote refrigerated cabinets.
Consequently, the delivery head for pumps of this — type can be very high.
Pumps must be dimensioned and designed accordingly.
A further disadvantage of such cooling systems is that the cold generator cannot be operated in a constant manner, but is subject to frequent fluctuations in its delivery capacity.
A refrigerated cabinet, which can be connected to a branched cooling system, is known from EP 3 076 106 A2. DE 102015 014378 Al relates to a method for controlling a circulation pump of acooling installation.
Taheri: “Revista de ciencias agronomicas.
Serie 8”, 31 October 2014 (2014-10- 31), XP055531963 discloses hydraulic switches, which can be incorporated in a conduction system.
DE 101 02 022 A1 discloses a water heating installation having a fire and a fuel cell system as well as a service water storage tank and a radiator arrangement which are connected via a hydraulic switch, to which the common consumer feed and return lines and the common feed and return lines of the heaters are — connected, to these feed and return lines.
In order to reduce the risk of installation faults, provision is made for a hydraulic switch to be provided with a shut-off valve, by way of which the connection between the feed and the return lines can be closed off. — Object
The object is therefore the disclosure of a refrigerated cabinet and a refrigerating system which eliminate the problems of the prior art, and which provide simpler and more reliable operation of a refrigerated cabinet. — Solution The object is fulfilled by a refrigerated cabinet with built-in hydraulic regulation, comprising an internal refrigerant circuit and connections for connection to a central refrigerant conduction system, wherein the internal refrigerant circuit comprises at least one conveyor device and a refrigerating device, wherein the conveyor device is a speed-controlled pump, and wherein a hydraulic switch is arranged between the internal refrigerant circuit and the connections to the central refrigerant conduction system, wherein, in a line which connects a connection of the refrigerated cabinet on the feed of a central refrigerant conduction system to a connection of the hydraulic switch, a shut-off device is arranged, and in a line which connects a connection of the refrigerated cabinet on the return of a central refrigerant conduction system to a connection of the hydraulic switch, a shut-off device is arranged.
The refrigerated cabinet permits the operation thereof with built-in hydraulic regulation, wherein pressure and temperature fluctuations, which are present on the refrigerant connections as a result of the refrigerant delivered by the central refrigerant conduction system, are compensated.
By means of the hydraulic switch, it is ensured that the requisite cooling demand for the refrigerating device
— can be delivered.
In particular, the conveyor device of the refrigerated cabinet can be optimally adapted to the demand of the refrigerating device.
The volumetric flow of refrigerant conveyed in the internal refrigerant circuit is regulated by means of the conveyor device.
The conveyor device thus executes the take-up of refrigerant via the hydraulic switch.
By the separation of the internal refrigerant circuit from the external refrigerant circuit of the central refrigerant conduction system, no residual delivery head needs to be incorporated for the conveyor device of the refrigerated cabinet, in order to accommodate a potentially highly branched pipe network of the central refrigerant conduction system.
The conveyor device of the refrigerated cabinet can therefore be configured with a reduced rating.
Moreover, the refrigerated cabinet is operable independently of the central refrigerant conduction system and the capacity of the cold generator.
A refrigerated cabinet of this type can also be connected by retrofitting to an existing central refrigerant conduction system, provided that the requisite reserve capacity is then still available to the central refrigerant conduction system and the cold generator.
The refrigerated cabinet permits a decoupling of the generator side, the consumer side and a highly extensive pipe network of a central refrigerant conduction system, for example in the retail food trade.
The refrigerating device of the refrigerated cabinet can comprise, for example, a ventilator and a heat exchanger wherein, by means of the ventilator, air is conveyed over the heat exchanger.
By means of the refrigerant, the heat exchanger is correspondingly brought to temperature, and the air which is conveyed by means of the ventilator surrenders its heat to the heat exchanger,
— such that the air circulating in a refrigerated cabinet can be cooled.
The refrigerated cabinet can be configured, for example, as a refrigerated shelf, an ice compartment or freezer cabinet, or as a cold store, and incorporates a merchandise space, in which the goods to be chilled are accommodated.
Refrigerated cabinets of this type, in various embodiments, are known from the prior art.
The internal refrigerant circuit comprises a feed and a return, wherein the hydraulic switch is integrated in the refrigerant circuit such that the admission and discharge of refrigerant is possible via the central refrigerant conduction
— system.
A connection of the refrigerated cabinet, which is connected to a feed of the central refrigerant conduction system, is coupled to the hydraulic switch such that the opposing connection terminates in the feed of the internal refrigerant circuit.
Correspondingly, the connection of the refrigerated cabinet which is connected to the return of the central refrigerant conduction system is connected to the hydraulic switch such that, on the hydraulic switch, a connection to the return of the internal refrigerant circuit is arranged in opposition to said 5 connection.
The hydraulic switch can be arranged horizontally, wherein the admission of refrigerant at a lower temperature level is executed via the feed of the central refrigerant conduction system, such that the refrigerant at said lower temperature level is fed to a lower region of the hydraulic switch.
The connection to the feed of the internal refrigerant circuit is then also located in the lower region of the hydraulic switch.
The opposing connections to the return of the internal refrigerant circuit, and a line which is connected to the connection on the return of the central refrigerant conduction system, are located in the upper region of the hydraulic switch.
However, the hydraulic switch can also be arranged vertically.
As the hydraulic switch which is arranged in a refrigerated cabinet is generally configured with a more compact construction than hydraulic switches in heating and/or cooling systems, no stratification occurs therein, in the majority of cases.
Moreover, the occasionally very high flow velocities of the refrigerant prevent any stratification in the hydraulic switch.
Only in embodiments with a structurally larger hydraulic switch and lower flow velocities of the refrigerant can stratification become established.
The refrigerant admitted to the hydraulic switch in the upper region can thus assume a higher temperature level than in the lower region.
In the event of a greater influx of refrigerant than that required by the refrigerated cabinet, this results in a
— reduction of the temperature of the refrigerant which is stored in the hydraulic switch, or in an increase in the quantity of refrigerant at a lower temperature.
Stratification in the hydraulic switch is altered correspondingly, wherein the temperature limits are displaced upwards.
If the central refrigerant conduction system supplies a smaller quantity of refrigerant than that required by the refrigerant, the conveyor device draws refrigerant from the reserve in the hydraulic switch.
Stratification in the hydraulic switch is thus altered such that the temperature level in the hydraulic switch or the quantity of refrigerant at a higher temperature level rises.
The shut-off devices can be configured, for example, as shut-off ball valves and, — either manually and/or remotely, by means of a corresponding device, permit the internal refrigerant circuit and the hydraulic switch of the refrigerated cabinet to be isolated from the central refrigerant conduction system.
In the feed of the internal refrigerant circuit, a valve can be arranged upstream of the conveyor device in the direction of flow which, by means of a bypass, connects the return of the internal refrigerant circuit to the feed of the internal refrigerant circuit.
The valve can be configured, for example, as a three-way valve, wherein only a throughflow of refrigerant from the connection of the hydraulic switch in the feed of the internal refrigerant circuit and via the bypass — in the direction of flow of the refrigerant to the refrigerating device is permitted.
Any backflow of refrigerant from the feed of the internal refrigerant circuit to the hydraulic switch is not possible via the valve.
The valve, for example, can be motor-actuated, and permits the execution of temperature regulation, in order to ensure the maintenance of a narrow temperature band.
In the event of low cooling — demand from the refrigerating device, refrigerant from the return of the internal refrigerant circuit can be fed back via the bypass to the feed of the internal refrigerant circuit.
This can be executed, for example, if the temperature in the return of the internal refrigerant circuit does not deviate, or only deviates by a small margin, from the temperature of the refrigerant in the feed of the internal refrigerant circuit.
The temperature differences required for this purpose can be predefined and adjusted on the control side and adapted to the cooling demand of further refrigerated cabinets in a cooling system or to the cooling capacity of the cold generator.
Capacity regulation in accordance with the cooling demand of refrigerating devices is executed by means of the at least one conveyor device of the refrigerated cabinet.
For the control of the valve and of the at least one conveyor device, the refrigerated cabinet can comprise an internal control unit.
In the event of only a limited cooling demand, or no cooling demand, for the refrigerating device of the refrigerated cabinet, the valve, for example, can regulate the conveyance of refrigerant such that refrigerant is fed back to the refrigerating — device via the bypass.
In embodiments with structurally large hydraulic switches and low flow velocities of the refrigerant, a feedback of refrigerant via the bypass may then be selected, for example, if the refrigerant which is present in the hydraulic switch is to undergo additional cooling, or if stratification in the refrigerant admitted thereto exceeds a threshold value.
The threshold value, for example, can be representative of a temperature at a specific location in the hydraulic switch.
As no cooling demand, or only a limited cooling demand, prevails on the refrigerating device of the refrigerated cabinet, the refrigerant which is admitted — via the central refrigerant conduction system can be employed for the further supply of the hydraulic switch with refrigerant at a specific temperature, such that a definable state is achieved.
However, the separation of the internal refrigerant circuit from the hydraulic switch can also be executed, for example, if only a limited cooling demand, or no cooling demand for the refrigerating device is — present, and the temperature of refrigerant conveyed in the central refrigerant conduction system exceeds a specific temperature threshold.
In such embodiments, the cold stored in the hydraulic switch can then be employed for reducing the refrigerant in the central refrigerant conduction system.
Consequently, the hydraulic switch can also be employed as a cold store.
The conveyor device of the refrigerated cabinet is a speed-controlled pump which permits the stepless operation of the refrigerated cabinet, in accordance with the requisite cooling capacity.
In particular, the capacity of the pump can be lower than in refrigerated cabinets from the prior art with no hydraulic switch, as no residual delivery head is required for the central refrigerant conduction system and the refrigerant conveyed therein.
The speed-controlled pump is therefore operated in accordance with the actual capacity requirement of the refrigerated cabinet.
A non-return valve can be arranged in the return of the internal refrigerant circuit.
The non-return valve prevents any backflow of refrigerant from the hydraulic switch into the return.
The above-mentioned object is also fulfilled by a refrigerating system comprising at least one refrigerated cabinet according to one of the above-described variants,
a central cold generator and a central refrigerant conduction system having a central conveyor device, wherein the at least one refrigerated cabinet is connected by means of connections to the central refrigerant conduction system, which is connected to the cold generator.
The central refrigerant conduction system can further comprise a hydraulic switch.
A hydraulic switch in the central refrigerant conduction system permits a further decoupling of the cold generator from that part of the central refrigerant conduction system which is connected to the at least one refrigerated cabinet.
A first central conveyor device can be arranged between the hydraulic switch and the cold generator in the return of the central refrigerant conduction system, and a second central conveyor device can be arranged between the hydraulic switch and the at least one refrigerated cabinet in the feed of the central refrigerant conduction system.
In embodiments with no hydraulic switch in the central refrigerant conduction system, a central conveyor device can be arranged in the return of the central refrigerant conduction system.
In particular, the central conveyor devices can also be speed-controlled pumps.
The central conveyor devices can further be rated and dimensioned to a smaller capacity, on the grounds that, for the latter, only the pressure drop up to the point of hydraulic decoupling is of relevance.
The central conveyor devices or speed- controlled pumps are not required to convey the refrigerant through an additional pipe system of the refrigerated cabinet itself.
Moreover, the speed-controlled pump of an intermediate circuit can be individually rated for each application.
The refrigerating system thus permits the employment of a plurality of refrigerated cabinets, which are configured independently of the site of installation and the configuration of the central refrigerant conduction system.
Depending upon the configuration of the central refrigerant conduction system with or without an independent hydraulic switch, the central conveyor devices are subject to different requirements.
In all embodiments, however, the central conveyor devices can be dimensioned to a lower rating than in known embodiments from the prior art, as the conveyor devices are not required to conduct the refrigerant through the refrigerated cabinet itself.
In particular, in refrigerating systems of this type, it is possible for only one of the conveyor devices to be adjusted in accordance with the configuration of the central refrigerant conduction system, in order to fulfill the corresponding requirements.
It is not necessary for the conveyor devices of the refrigerated cabinets to be adjusted.
Moreover, hydraulic equalization is
— provided, without the necessity for the execution of separate measures for a central refrigerant conduction system.
Refrigerating systems of this type essentially permit a decoupling of the generator side, the consumer side, and a, in some cases, highly extensive pipe
— network of a central refrigerant conduction system, particularly in the retail food trade.
As essential advantage of the refrigerated cabinet described herein is the separation of the internal refrigerant circuit from the central refrigerant conduction system, independently of the distance from the refrigerated cabinet to a cold generator.
The overall capacity demand for a refrigerating system of this type having such refrigerated cabinets can be reduced, and is not subject to wide fluctuations, as the individual refrigerated cabinets regulate their own demand for refrigerant. Further advantages, characteristics and potential configurations proceed from the following figurative description of exemplary embodiments, which are not to be considered by way of limitation. Brief description of the figures In the drawings:
Fig. 1 shows a schematic representation of a refrigerated cabinet having a hydraulic switch in a first form of embodiment; Fig 2 shows a schematic representation of a refrigerated cabinet having a hydraulic switch in a second form of embodiment;
Fig. 3 shows a schematic representation of a refrigerating system with a cold generator and a plurality of refrigerated cabinets having a hydraulic switch; and
Fig. 4 shows a schematic representation of a refrigerating system with a cold generator, a central hydraulic switch and a plurality of refrigerated cabinets having a hydraulic switch. In the drawings, components identified by the same reference numbers are essentially mutually equivalent, unless indicated otherwise. Moreover, any illustration and description of constituent elements which are not essential to the understanding of the technical instruction disclosed herein have been omitted. Detailed description of exemplary embodiments
Fig. 1 shows a schematic representation of a refrigerated cabinet 10 having a hydraulic switch 22 in a first form of embodiment.
The refrigerated cabinet 10, for example, can form part of a refrigerating system 100, having a plurality of such refrigerated cabinets 10, which is arranged in a supermarket.
The refrigerated cabinet 10 can be configured, for example, as a refrigerated shelf or an ice compartment, and can be intended for the accommodation of goods.
Goods are brought to temperature by means of a refrigerating device 30, by means of which cooled air is circulated and cooled.
The refrigerated cabinet 10 comprises a housing 12 and connections 14 and 16. The connections 14 and 16 are connected to a feed and a return of an internal refrigerant circuit.
Via the connections 14 and 16, the refrigerated cabinet 10 is connected to the feed 122 and the return 124 of a central refrigerant conduction system.
By means of the refrigerant conduction system 120, a refrigerant is admitted and evacuated.
A valve 18 is arranged in a line 20 in the feed of the refrigerant circuit.
The valve 18, in common with the valve 42, can be configured as a shut-off ball valve, and its function is the isolation of the refrigerant circuit of the refrigerated cabinet 10
— from the central refrigerant conduction system 120. To this end, the valves 18 and 42 can be manually actuated and/or motor-actuated.
The line 20 incorporates a connection to a hydraulic switch 22. The hydraulic switch 22, other than as represented in Fig. 1, can also be arranged with a horizontal orientation, such that a corresponding stratification with refrigerant in the interior of the hydraulic
— switch 22 can be established.
In opposition to a connection to the line 20, the hydraulic switch 22 incorporates a connection to a line 28 of the feed.
A speed- controlled pump 26 is moreover arranged in the line 28. By means of the pump 26, in accordance with cooling demand, the guantity of refrigerant reguired is regulated.
The size of the hydraulic switch 22 and the flow velocities of the refrigerant dictate whether stratification can be established in the hydraulic switch 22. In general, on the grounds of the small dimensions of the hydraulic switch 22 and the high flow velocities, no stratification can be established.
The refrigerating device 30 comprises a heat exchanger 34 and a ventilator 32. The ventilator 32 conducts air over the heat exchanger 34. The heat exchanger 34 absorbs heat from the air which is conducted thereover, and thus executes the cooling of said air.
By means of the ventilator 32, air is additionally circulated in a merchandise space, in which goods to be chilled are accommodated.
From the refrigerating device 30, a line 36 of the refrigerant circuit return runs to a further — connection of the hydraulic switch 22. A further connection is provided in opposition to said connection, which is connected to a line 40. The line 40 incorporates the valve 42, and terminates at a connection 16. Via the connection 16, the refrigerated cabinet 10 is connected to the return 124 of the — central refrigerant conduction system 120. In the operation of the refrigerated cabinet 10, a refrigerant is admitted via the refrigerant conduction system 120. The refrigerant is admitted via the feed 122 and the connection 14 to the feed, and the line 20 of the refrigerated cabinet 10. From thence, the refrigerant enters the hydraulic switch 22 and, depending upon the cooling demand of the refrigerated cabinet 10, can essentially follow three different paths.
The refrigerant either flows essentially through the hydraulic switch 22 and, essentially in its entirety, enters the line 28 and is employed for cooling via the refrigerating device 30. Correspondingly, the refrigerant from the — return can also flow through the hydraulic switch 22 and, essentially via the line section 40, is fed back to the return 124. In a further operating mode, the refrigerant flows into the hydraulic switch 22, wherein essentially no refrigerant is conveyed by means of the pump 26. This — then results in a throughflow in the hydraulic switch 22 between the connections to the lines 20 and 40, or in a charging of the hydraulic switch 22, wherein the refrigerant accommodated therein is correspondingly cooled such that, for example, the quantity of refrigerant at a higher temperature decreases until, for example, the entirety of the refrigerant accommodated therein assumes the same temperature.
In both cases, there is a backflow of refrigerant from the hydraulic switch 22 into the line 40.
In a further operating mode, a proportion of the refrigerant which is introduced into the hydraulic switch 22 via the feed 122 and the line 20 can be admitted to the refrigerating device 30 for the purposes of cooling the refrigerant which is accommodated in the hydraulic switch 22 and for the purposes of cooling.
Thus, depending upon the cooling demand of the refrigerated cabinet 10, there is resulting throughflow of the admitted refrigerant through the hydraulic switch 22 from the line 20 to the line 28, or from the line 36 to the line 40, a division of the incoming refrigerant streams, or essentially only a single influx of refrigerant into — the hydraulic switch 22 and a corresponding throughflow via the connections to the lines 20 and 40. In the refrigerated cabinet 10, a decoupling of the internal refrigerant circuit of the refrigerated cabinet 10 from the central refrigerant conduction system 120 is — achieved.
Correspondingly, it is only necessary for the pump 26 of the refrigerated cabinet 10 to be dimensioned and selected in accordance with the maximum delivery capacity to be provided for the refrigerated cabinet 10. It is not necessary for the pump 26 to deliver any residual delivery head for the central refrigerant conduction system 120. Moreover, the refrigerated cabinet 10 is — configured independently of the configuration and the length of the refrigerant conduction system 120. The refrigerated cabinet 10, for example, can be integrated in a refrigerating system 100, without any necessity for complex mutual tailoring of the refrigerating system 100 or the refrigerated cabinet 10. For a refrigerating system 100 of this type, it is only necessary for the overall cooling — capacity delivered by a cold generator 110 to be defined.
Correspondingly, the delivery capacity for a cold generator 110 can increase if, for example, a further refrigerated cabinet 10 is added to a central refrigerant conduction system 120.
A central refrigerant conduction system 120 can also incorporate pumps 130, 150
(c.f Figs. 3 and 4), which can influence cooling capacity with respect to the quantity of refrigerant delivered. The refrigerated cabinet 10 permits hydraulic regulation, without the necessity for any equalization with the central refrigerant conduction system 120. Moreover, the refrigerated cabinet 10 can compensate temperature fluctuations in the refrigerant admitted via the refrigerant conduction system 120, and can compensate pressure differences, with no resulting impairment of the cooling capacity of the refrigerated cabinet 10.
Fig. 2 shows a schematic representation of a refrigerated cabinet 10 having a hydraulic switch 22 in a second form of embodiment. The refrigerated cabinet 10 — in the second form of embodiment is distinguished from the refrigerated cabinet 10 in the first form of embodiment by the valve 44. The valve 44 is arranged upstream in the feed of the refrigerant circuit of the refrigerated cabinet 10, in the line 28 of the pump 26, in the direction of flow of refrigerant. The valve 44 is configured as a three-way valve and, by means of a line 24 which is configured as a bypass, connects the return of the refrigerant circuit of the refrigerated cabinet 10 to the feed. The valve 44 thus connects the section of the line 36, which is arranged downstream of the non-return valve 38 in the refrigerant streams, to the section of the line 28 which is arranged upstream of the pump 26. The valve 44 is motor-actuated, in order to deliver a refrigerant flux via the pump — 26, the refrigerating device 30 and the non-return valve 38, without the extraction of refrigerant from the hydraulic switch 22. The valve 44 can also be switched such that no refrigerant is admitted via the line 24. In further operating modes, intermediate settings of the valve 44 are also possible. — By means of the valve 44, refrigerant can be routed from the return of the internal refrigerant circuit of the refrigerated cabinet 10 to the feed of the internal refrigerant circuit. This state can then be in force, for example, if the backflow of refrigerant in the line 36 assumes a temperature which is only slightly higher than the temperature of the refrigerant in the feed, in the line 28. In the absence of any further cooling demand, the speed-controlled pump 26 can be switched off. The non-return valve 38 prevents any backflow of refrigerant.
Fig. 3 shows a schematic representation of a refrigerating system 100 with a cold generator 110 and a plurality of refrigerated cabinets 10 having a hydraulic switch 22. The refrigerated cabinets 10 correspond to the refrigerated cabinets 10 in the first form of embodiment. In place of refrigerated cabinets 10 according to the first form of embodiment, refrigerated cabinets 10 according to the second form of embodiment can also be provided. A refrigerating system 100 can also comprise refrigerated cabinets 10 according to the first and second form of embodiment. The refrigerating system 100 comprises a cold generator 110 with a central refrigerating device, by means of which a refrigerant or refrigerating agent is cooled and, by means of heat exchangers, a reduction in a refrigerant conveyed in the refrigerant conduction system 120 is achieved. The refrigerant conduction — system 120 is connected via the feed 122 and the return 124 to the individual refrigerated cabinets 10. The refrigerated cabinets 10 are connected via the connections 14 to the feed 122 and via the connections 16 to the return 124 of the refrigerant conduction system 120. A speed-controlled pump 130 is arranged in the return of the refrigerant conduction system 120. In comparison with the — pumps of conduction systems from the prior art, the pump 130 can be of reduced capacity and of smaller construction, as only the conveyance of refrigerant within the refrigerant conduction system 120 is reguired. The pump 130 is not reguired to pump refrigerant through the refrigerated cabinets 10. As a result of the separation of the refrigerant circuit in the refrigerated cabinets 10 from the refrigerant conduction system 120, the pumps 26 are configured independently of the configuration and the length of the refrigerant conduction system 120, and it is only necessary for the pump 130 to be rated in accordance with the overall length of the refrigerant conduction system and the quantity of refrigerant to be conveyed therein.
In comparison with known refrigerating systems from the prior art, the pumps 26 and 130 can therefore be configured with a lower capacity rating, thereby additionally resulting in a substantial reduction in the energy demand, and thus the operating costs thereof.
The refrigerated cabinets 10 moreover provide hydraulic equalization vis-a-vis the refrigerant conduction system 120. The position of refrigerated cabinets 10 in the refrigerant conduction system 120, i.e. the distance thereof from the cold
— generator 110 and the resulting delivery head, does not compromise the cooling capacity of the refrigerated cabinets 10, and also does not result in a requirement for the delivery of a very substantial temperature reduction in the refrigerant by the cold generator 110.
In particular, the pumps 26 of the refrigerated cabinets 10 can be optimally adapted to the demand of the refrigerating device 100, as it is not necessary to incorporate any residual delivery head for the refrigerant conduction system 120. Consequently, the capacity of the pumps 26 invariably corresponds to the actual cooling demand required.
The pump 130 is configured in accordance with the configuration of the refrigerant conduction system 120, and is adapted to demand for cooling capacity in the refrigerant conduction system 120. At all times, the pump 130 is operated such that a given temperature prevails at specific positions in the refrigerant
— conduction system 120. The refrigerating system 100, and the refrigerated cabinets 10 of the refrigerating system 100, comprise sensor devices for the detection of temperatures.
Additionally, the latter can comprise detection devices for the detection of delivery volumes of refrigerant.
The refrigerating system 100 comprises a central control unit which regulates the operation of the cold
— generator 110 and the operation of the pump 130. The refrigerated cabinets 10 comprise a dedicated controller which, depending upon cooling demand established, regulates the pump 26 and, optionally, a valve 44. The refrigerating system 100 thus provides a decoupling of the internal refrigerant circuits of the refrigerated cabinets 10 from the refrigerant circuit in the refrigerant conduction system 120 and the cold generator 110.
Fig. 4 shows a schematic representation of a refrigerating system 100 with a cold generator 110, a central hydraulic switch 140 and a plurality of refrigerated cabinets 10 having a hydraulic switch 22. The refrigerant conduction system 120 is configured in a branched arrangement, and comprises a plurality of parallel-oriented feeds 122 and returns 124. These terminate in a common feed 122 and in a common return 124, which are connected to a central hydraulic switch 140. The hydraulic switch 140 comprises further connections, from which a return 124? and a feed 122? extend, which are coupled to the cold generator 110. The connections of the hydraulic switch 140 — are provided such that the feed 122 is arranged opposite the feed 122°, and the return 124 is arranged opposite the return 124”. In the feed 122 of the refrigerant conduction system 120, a further speed- controlled pump 150 is arranged, which regulates the admission of refrigerant to — the refrigerated cabinets 10. Depending upon the measured temperatures, the speeds of the pumps 26 of the refrigerated cabinets 10, the pump 130 and the pump 150 can be adjusted. By the decoupling of individual sections or refrigerated cabinets 10 from the pipe system 120 by means of the hydraulic switches 22, and the separation of the refrigerant conduction system 120 from the — generator 110 by means of the hydraulic switch 140, the pumps can be operated in a manner which is individually adapted to their respective sections. Analogously, higher cooling demand in the refrigerated cabinets 10 can be compensated by the hydraulic switches 22 within the refrigerated cabinets 10. In particular, the refrigerating system 100 is characterized in that even refrigerated cabinets 10 which are arranged remotely can be configured identically to other refrigerated cabinets 10. The pumps 26 of remotely positioned refrigerated cabinets 10 are not required to assume a higher delivery capacity for the fulfilment of a comparable cooling demand, as the pumps 26 are only rated and required for the delivery of the cooling capacity which is actually required in the refrigerated cabinet 10. Hydraulic equalization by means of the switches 22 permits a built-in regulation of the refrigerated cabinets 10, with no resulting disadvantages for the refrigerant conduction system 120.
List of reference numbers 10 Refrigerated cabinet 12 Housing 14 Connection 16 Connection 18 Valve 20 Line 22 Switch 24 Line 26 Pump 28 Line 30 Refrigerating device 32 Ventilator 34 Heat exchanger 36 Line 38 Non-return valve 40 Line 42 Valve 44 Valve 100 Refrigerating system 110 Cold generator 120 Refrigerant conduction system 122 Feed 122° Feed 124 Return 124¢ Return 130 Pump 140 Switch 150 Pump