Control cabinet arrangement with heat recovery, a corresponding process and an infrastructure for the heat energy supply

Abstract

Control cabinet arrangement (1) with at least one control cabinet and at least one cooling unit (2) comprising a refrigeration unit (3), an inner air circuit (4) for air to be cooled from the control cabinet, and an outer air circuit (5) for ambient air, wherein a first air-liquid heat exchanger (6.1) of an evaporator of the refrigeration unit (3) is arranged in the inner air circuit (4), and a second air-liquid heat exchanger (6.2) of the condenser of the refrigeration unit (3) is arranged in the outer air circuit (5), wherein the condenser comprises a liquid-liquid heat exchanger (7) with which heat is transferred to a process fluid of a heat network (100) of a heat supply (101), wherein both the second air-liquid heat exchanger (6.2) and the liquid-liquid heat exchanger (7) are part of a first refrigerant circuit (8.1) of the refrigeration unit. (3) are characterized in that the first air-liquid heat exchanger (6.1) and the second air-liquid heat exchanger (6.2) are part of a second refrigerant circuit (8.2) which is fluidically separated from the first refrigerant circuit (8.1).

Description

[0001] The invention is based on a switch cabinet assembly comprising at least one switch cabinet and at least one cooling device, which comprises a refrigeration machine, an internal air circuit for air to be cooled from the switch cabinet, and an external air circuit for ambient air. A first air-liquid heat exchanger of an evaporator of the refrigeration machine is arranged in the internal air circuit, and a second air-liquid heat exchanger of the condenser of the refrigeration machine is arranged in the external air circuit. Such a switch cabinet assembly is known from DE 10 2020 105 359 A1.

[0002] Switch cabinet arrangements of the type described above are used, for example, to dissipate heat from an electrical switchgear system housed in at least one switch cabinet, which is used, for example, in industrial production, or from an IT infrastructure, such as a data center. The electrical switchgear systems or IT infrastructures have components with power losses, such as transformers, server racks, and the like, which are heat-sensitive and therefore require cooling. As the energy supply is converted to renewable energy sources, there is an increased need to optimize energy use in industry. The primary objective is to use the most energy-efficient production and manufacturing processes possible. Once the realizable potential in this regard has been largely exhausted, a further approach is to sensibly reuse the energy available as waste heat.

[0003] For example, DE 10 2009 021 294 A1 proposes a heat pump system comprising a liquid-to-liquid heat exchanger for a building, allowing waste heat to be used to heat domestic water. Furthermore, DE 10 2008 028 178 A1 and DE 10 2018 116 609 A1 disclose refrigeration devices with a liquid-to-liquid heat exchanger.

[0004] To date, the energy recovery from waste heat from control cabinets has mostly been achieved by heating production halls with the warm exhaust air from the external air circuit of the control cabinet cooling units. However, this use is only desirable when outside temperatures are cold. In summer, the warm exhaust air must be removed from the production buildings using additional measures, which often require additional energy.

[0005] It is therefore the object of the invention to utilize the heat released into the ambient air by the cooling device in a switch cabinet arrangement as mentioned above.

[0006] This object is achieved by a switch cabinet arrangement having the features of claim 1. The subordinate claim 10 relates to a corresponding method. Claim 12 describes an infrastructure for the supply of thermal energy. Advantageous embodiments are the subject of the dependent claims.

[0007] In a control cabinet arrangement, it is therefore provided that the condenser has a liquid-to-liquid heat exchanger, which transfers heat to a process fluid of a heat network of a heat supply system. Both the second air-to-liquid heat exchanger and the liquid-to-liquid heat exchanger are components of a first refrigerant circuit, in particular of the same refrigerant circuit, of the refrigeration machine.

[0008] The first air-liquid heat exchanger and the second air-liquid heat exchanger are part of a second refrigerant circuit, which is fluidically separated from the first refrigerant circuit. The second refrigerant circuit can, for example, be a natural circulation system, such as a thermosiphon or a heat pipe.

[0009] The heating network can, for example, be an existing district heating network of a municipal infrastructure. The liquid-to-liquid heat exchanger can, for example, be a plate heat exchanger, such as a counterflow plate heat exchanger. The process fluid can be water. The cooling device can be a cooling device suspended from a switch cabinet side wall, rear wall, or front door, for example, a cooling device that protrudes through a cutout in the side wall, rear wall, or door of the switch cabinet. The air taken up in the switch cabinet flows through the inner air circuit. The ambient air flows through the outer air circuit. The inner air circuit and the outer air circuit can each have a fan, with which the respective air is passed through the first air-to-liquid heat exchanger of the evaporator or the second air-to-liquid heat exchanger of the condenser for heat transfer.The cooling unit can also have a different design. For example, it can be a roof-mounted unit. The cooling unit can be attached to the control cabinet. The cooling unit can be a rack-mounted cooling unit for an IT cabinet, mounted in a 19-inch mounting plane of the IT cabinet. The cooling unit can be an inline cooling unit for a control cabinet row. The above list is also not exhaustive.

[0010] The liquid-liquid heat exchanger can be a component of the cooling device, for example, within a cooling device housing, for example, in the external air circuit. However, the liquid-liquid heat exchanger can also be located outside the housing. The liquid-liquid heat exchanger can be a plate heat exchanger, for example, a counterflow plate heat exchanger, or a liquid-liquid heat pump, but is not limited to these embodiments.

[0011] If the control cabinet cooling is implemented with at least one air-water heat exchanger, the thermal energy can be supplied to a further use in a building by means of the process fluid, for example water, for example via a domestic water network, such as a central hot water supply or a central hot water heating system.

[0012] The first refrigerant circuit can have a device for prioritizing one of the two heat exchangers mentioned. For example, it can be realized that depending on a process parameter, for example the temperature of the ambient air, either the second air-liquid heat exchanger or the liquid-liquid heat exchanger is prioritized. The prioritization can include, depending on the operating mode, only one of the two heat exchangers mentioned being supplied with a refrigerant from the first refrigerant circuit. The prioritization can also include both heat exchangers being supplied with a refrigerant from the first refrigerant circuit, wherein the volume flows of the refrigerant through a first of the heat exchangers mentioned can be varied in relation to a second of the heat exchangers mentioned depending on a process parameter, for example the temperature of the ambient air.For example, in hot summer months, the liquid-to-liquid heat exchanger can be prioritized over the air-to-liquid heat exchanger. The entire volume flow of the first refrigerant circuit can be routed exclusively or almost exclusively through the liquid-to-liquid heat exchanger. In cold winter months, the prioritization can be reversed, favoring the air-to-liquid heat exchanger, so that more heat is available for heating the area surrounding the control cabinet.

[0013] In the first refrigerant circuit, the second air-liquid heat exchanger of the condenser can be connected in parallel with the liquid-liquid heat exchanger of the condenser. For example, the liquid-liquid heat exchanger can be arranged in a bypass line that bridges the second air-liquid heat exchanger.

[0014] The first refrigerant circuit may include a switching valve, with which refrigerant is selectively supplied to the second air-liquid heat exchanger and / or the liquid-liquid heat exchanger. The switching valve may, for example, be a 3-way valve, preferably a modulating 3-way valve.

[0015] The switching valve, for example a modulating 3-way valve, can be arranged downstream between a compressor of the chiller and the second air-liquid heat exchanger and the liquid-liquid heat exchanger.

[0016] The control cabinet assembly can have a temperature sensor for determining an air temperature in the area surrounding the control cabinet assembly. The temperature sensor can be located outside the cooling device or inside the cooling device. The temperature sensor can be located, for example, in the external air circuit. A control unit of the control cabinet assembly can be configured to control the switching valve depending on an air temperature detected by the temperature sensor. For example, the control unit can be configured to prioritize the second air-liquid heat exchanger over the liquid-liquid heat exchanger during the winter months, so that the waste heat generated by the condenser is dissipated into the ambient air of the control cabinet assembly.Particularly in the summer months, when heating of the environment of the switch cabinet arrangement is not required or desired, the control unit can prioritize the liquid-liquid heat exchanger on the basis of the ambient temperature detected by the temperature sensor and control the switching valve to direct the refrigerant absorbed in the first refrigerant circuit at least partially or completely through the liquid-liquid heat exchanger.

[0017] The return of the second air-liquid heat exchanger and / or the return of the liquid-liquid heat exchanger in the first refrigerant circuit may have a one-way valve.

[0018] The described control cabinet arrangement can be implemented as a retrofit solution for existing control cabinet arrangements, keeping the retrofitting effort to a minimum. In one embodiment, the retrofit can be achieved, for example, by retrofitting a bypass line that is connected to the first refrigerant circuit via a switching valve, such as a 3-way valve, and bypasses the second air-liquid heat exchanger. For this purpose, the 3-way valve can be integrated into the first refrigerant circuit at the inlet of the air-liquid heat exchanger.

[0019] A method for operating a switch cabinet arrangement of the type described above can comprise operating the at least one cooling device, wherein thermal energy is extracted from the at least one switch cabinet, in particular from the air contained in the switch cabinet. For this purpose, the thermal energy can be transferred to a refrigerant of the first refrigerant circuit by means of the first air-to-refrigerant heat exchanger, which is supplied with air, for example, by means of a fan. The method can further comprise transferring the thermal energy to a process fluid of a heating network of a heat supply system by means of the liquid-to-liquid heat exchanger. For this purpose, the thermal energy extracted from the switch cabinet air by the first air-to-liquid heat exchanger and transferred to the refrigerant of the first refrigerant circuit can be transferred to the process fluid of the heating network by means of the liquid-to-liquid heat exchanger.

[0020] The method may further comprise transferring the thermal energy from the process fluid to a central heating system of a thermal energy consumer, for example, a building. Transferring the thermal energy using the liquid-liquid heat exchanger may comprise transferring the thermal energy to a district heating network of a municipal infrastructure. The thermal energy may be transferred directly or indirectly to a central hot water supply or to a central heating system of a building.

[0021] According to another aspect of the invention, an infrastructure for thermal energy supply is described, which comprises at least one switch cabinet arrangement of the type described above, a heat network of a heat supply, for example, a district heating network of a municipal infrastructure, and a plurality of thermal energy consumers, for example, buildings, in particular a respective central heating system of the buildings. The thermal energy consumers can be connected via the heat network to the at least one switch cabinet arrangement for heat transfer.

[0022] At least one of the heat energy consumers can have another liquid-to-liquid heat exchanger, for example, a liquid-to-liquid heat pump. The other liquid-to-liquid heat exchanger, for example, the liquid-to-liquid heat pump, can be supplied with the process fluid from the heating network for heat transfer from the process fluid, for example, to a central heating system or a central hot water supply of a building.

[0023] The liquid-liquid heat pump may be a combined liquid-liquid heat pump and air-liquid heat pump, in which in a first operating mode the liquid-liquid heat pump is activated and the air-liquid heat pump is deactivated, and in which in a second operating mode the liquid-liquid heat pump is deactivated and the air-liquid heat pump is activated, and in which in a third operating mode both the liquid-liquid heat pump and the air-liquid heat pump are activated.

[0024] Heating networks can connect central heating systems to connected buildings via pipelines and transfer stations. They enable heat sources such as control cabinets, which are less efficient or impossible to use in decentralized systems, to be used for heating. Seasonal storage systems can decouple heat generation and consumption; for example, heat energy transferred from the control cabinet to the heating network during the summer months can be stored for the heating season.

[0025] Further details of the invention are explained with reference to the following figures. Fig. 1 is a circuit diagram of an exemplary embodiment of a cooling device for a switch cabinet arrangement according to the invention; Fig. 2 a front view of an exemplary embodiment of a cooling device for a switch cabinet arrangement according to the invention with the front cover removed; and Fig. 3 a schematic representation of an exemplary infrastructure for heat energy supply.

[0026] The Fig. The circuit diagram of a cooling device 2 shown in Figure 1 illustrates an embodiment of the cooling device 2, which, in addition to the refrigeration machine 3 with its first refrigerant circuit 8.1, further comprises a second refrigerant circuit 8.2 separated from the first refrigerant circuit 8.1 and configured for natural circulation, for example, as a so-called heat pipe. The second refrigerant circuit 8.2 is thus a passive refrigerant circuit and can provide cooling of the control cabinet air without consuming energy, particularly when the required cooling capacity is low or the ΔT between the ambient air and the air inside the control cabinet is high.

[0027] The refrigeration machine 3 comprises a compressor 14, a condenser with parallel air-liquid heat exchangers 6.2 and liquid-liquid heat exchanger 7, an expansion valve 15, and a further air-liquid heat exchanger 6.1 in the internal air circuit, which are fluidly connected to each other via a first refrigerant circuit 8.1. The second air-liquid heat exchanger 6.2 and the liquid-liquid heat exchanger 7 are connected in parallel. In particular, a switching valve, for example a 3-way valve 10, is arranged upstream of the heat exchangers 6.2, 7, so that refrigerant provided downstream of the compressor 14 and further heated by the compression can be selectively supplied to the second air-liquid heat exchanger 6.2 and / or the liquid-liquid heat exchanger 7.The 3-way valve 10 can, in particular, be a modulatable 3-way valve, which allows the refrigerant volume flow provided downstream by the compressor 14 to be fed in any desired proportions to the second air-liquid heat exchanger 6.2 or the liquid-liquid heat exchanger 7. Both parallel-connected heat exchangers 6.2, 7 have a one-way valve 13 on the return side to prevent refrigerant from flowing back into the respective heat exchanger 6.2, 7, for example, when the other heat exchanger 6.2, 7 is subjected to a comparatively higher refrigerant pressure, corresponding to the previously described modulation, which is possible with the modulatable 3-way valve 10.

[0028] The chiller 3 is thermally coupled to a heat network 100 for heat supply via a liquid-to-liquid heat exchanger. If the 3-way valve 10 is set so that the liquid-to-liquid heat exchanger 7 is supplied with refrigerant compressed and heated by the compressor 14, the heat absorbed in the refrigerant can be transferred to a process fluid of the heat network 100, for example, water.

[0029] The Fig. Figure 2 shows an embodiment of a cooling device according to the invention, which is designed as a wall-mounted device, for example for suspended installation in or on a switch cabinet wall or switch cabinet door, for example in an opening in a flat part of a switch cabinet housing. It can also be seen that the liquid-liquid heat exchanger 7, which is essential to the invention, is accommodated within a housing of the cooling device 2 in the present embodiment. The additional liquid-liquid heat exchanger does not change the external design of the cooling device 2. The cooling device 2 only has a supply line 7.1 and a return line 7.2 for the liquid-liquid heat exchanger 7, which protrude from the housing of the cooling device 2 and via which the liquid-liquid heat exchanger 7 is connected to a heating network 100 of a heat supply 101 (cf. Fig. 3) can be connected.

[0030] The cooling device 2 has a temperature sensor 11, which is connected to a control unit 12 of the cooling device 2. Deviating from the embodiment according to Fig. 2, the control unit 12 can also be designed and arranged independently of the cooling device, for example, within the control cabinet housing of the control cabinet arrangement. The temperature sensor 11 can also be part of the cooling device 2 and, for example, be arranged within the external air circuit 5. However, the temperature sensor 11 can also be arranged outside the cooling device 2, for example, on an outer side of the housing of the cooling device, or on another component of the control cabinet arrangement that is exposed to the ambient air and is preferably not exposed to any thermal stress from the control cabinet arrangement.

[0031] In the Fig. Figure 3 shows an exemplary infrastructure comprising various heat sources, particularly in the form of switch cabinet rows, in a schematically depicted factory hall. The switch cabinet rows can be arranged in a cold-aisle / warm-aisle configuration or have inline cooling units. The cooling units can also be provided as roof-mounted units or as wall-mounted units (see Figure 3). Fig. 2). The waste heat produced by the switch cabinet arrangements 1 can be disposed of in the manner described in Fig. 1 via a liquid-liquid heat exchanger 7 to a heat network 100 of a heat supply 101. The heat supply can, for example, have a plurality of heat energy consumers 200, for example, buildings. A further liquid-liquid heat exchanger 203, for example, a heat pump, can be arranged within the building 200.

[0032] Although only a heat transfer from the process fluid of the heating network 100 to another fluid of the central heating system 201 is required for the transfer of heat from the heating network 100 to the central heating system 201, the heat exchanger 203 can be designed as a combined liquid-liquid heat pump and air-liquid heat pump in order to enable the operator of the building, for example for cost reasons, to switch between the heat supply from the heating network 100 or the ambient air, or to set a mixed operation with any weighting of the two heat sources.For example, if the building 200 has a photovoltaic system for operating the air-liquid heat pump, the air-liquid heat pump can be preferred and only the heat output that cannot be obtained with the air-liquid heat pump using the energy generated by the photovoltaic system can be obtained from the heating network 100.

[0033] The features of the invention disclosed in the above description, in the drawings and in the claims may be essential for the realization of the invention both individually and in any combination. List of reference symbols 1 Control cabinet arrangement 2 cooling device 3 Refrigeration machine 4 inner air circuit 5 External air circuit 6.1 first air-liquid heat exchanger 6.2 second air-liquid heat exchanger 7 Liquid-liquid heat exchangers 8.1 first refrigerant circuit 8.2 second refrigerant circuit 9 Bypass line 10 changeover valve 11 Temperature sensor 12 Control unit 13 One-way valve 14 compressors 15 Expansion valve 100 heating network 101 Heat supply 200 buildings 201 central heating system 203 Heat exchanger / heat pump

Claims

[1] Switch cabinet arrangement (1) with at least one switch cabinet and at least one cooling device (2), which has a refrigeration machine (3), an internal air circuit (4) for air to be cooled from the switch cabinet and an external air circuit (5) for ambient air, wherein a first air-liquid heat exchanger (6.1) of an evaporator of the refrigeration machine (3) is arranged in the internal air circuit (4) and a second air-liquid heat exchanger (6.2) of the condenser of the refrigeration machine (3) is arranged in the external air circuit (5), wherein the condenser has a liquid-liquid heat exchanger (7) with which heat is transferred to a process fluid of a heat network (100) of a heat supply (101), wherein both the second air-liquid heat exchanger (6.2) and the liquid-liquid heat exchanger (7) are components of a first refrigerant circuit (8.1) of the refrigeration machine (3), characterized bythat the first air-liquid heat exchanger (6.1) and the second air-liquid heat exchanger (6.2) are part of a second refrigerant circuit (8.2) which is fluidically separated from the first refrigerant circuit (8.1). [2] Switch cabinet arrangement (1) according to claim 1, wherein in the first refrigerant circuit (8.1) the second air-liquid heat exchanger (6.2) of the condenser is connected in parallel to the liquid-liquid heat exchanger (7) of the condenser. [3] Switch cabinet arrangement (1) according to claim 1 or 2, wherein the liquid-liquid heat exchanger (7) is arranged in a bypass line (9) which bridges the second air-liquid heat exchanger (6.2). [4] Switch cabinet arrangement (1) according to one of the preceding claims, in which the first refrigerant circuit (8.1) has a changeover valve (10) with which the refrigerant is selectively supplied to the second air-liquid heat exchanger (6.2) and / or the liquid-liquid heat exchanger (7), wherein the changeover valve (10) is preferably a modulating 3-way valve. [5] Switch cabinet arrangement (1) according to claim 4, wherein the changeover valve (10), preferably the modulating 3-way valve, is arranged downstream between a compressor (14) of the refrigeration machine (3) and the second air-liquid heat exchanger (6.2) and the liquid-liquid heat exchanger (7). [6] Switch cabinet arrangement (1) according to claim 4 or 5, which has a temperature sensor (11) for determining an air temperature in the environment of the switch cabinet arrangement (1), wherein a control unit (12) of the switch cabinet arrangement (1) is designed to control the changeover valve (10) depending on an air temperature detected by the temperature sensor (11). [7] Switch cabinet arrangement (1) according to one of the preceding claims, in which a return of the second air-liquid heat exchanger (6.2) and / or the liquid-liquid heat exchanger (7) in the first refrigerant circuit (8.1) has a one-way valve (13). [8] Switch cabinet arrangement (1) according to one of the preceding claims, in which the second refrigerant circuit (8.2) is a natural circulation, particularly preferably a heat pipe. [9] Switch cabinet arrangement (1) according to one of the preceding claims, in which the liquid-liquid heat exchanger (7) is a plate heat exchanger, preferably a counterflow heat exchanger. [10] Method for operating a switch cabinet arrangement (1) according to one of the preceding claims, the method comprising the steps: - operating the at least one cooling device (2), wherein thermal energy is extracted from the at least one control cabinet via the first refrigerant circuit (8.1) and / or the second refrigerant circuit (8.2); and - Transferring the thermal energy extracted via the first refrigerant circuit (8.1) to a process fluid of a heat network (100) of a heat supply (101) using the liquid-liquid heat exchanger (7). [11] Method according to claim 10, which comprises transferring the thermal energy from the process fluid to a central heating system (201) of a thermal energy consumer (200), for example a building. [12] Infrastructure for the heat energy supply, the at least one switch cabinet arrangement (1) according to one of claims 1 to 9, a heat network (100) of a heat supply (101) and a plurality of heat energy consumers (200), for example buildings, which are connected via the heat network (100) to the at least one switch cabinet arrangement (1) for heat transfer. [13] Infrastructure according to claim 12, wherein at least one of the heat energy consumers (200) comprises a liquid-liquid heat pump (203) supplied with the process fluid from the heat network (100). [14] Infrastructure according to claim 13, wherein the liquid-liquid heat pump (203) is a combined liquid-liquid heat pump and air-liquid heat pump, wherein in a first operating mode the liquid-liquid heat pump is activated and the air-liquid heat pump is deactivated, and wherein in a second operating mode the liquid-liquid heat pump is deactivated and the air-liquid heat pump is activated, and wherein in a third operating mode both the liquid-liquid heat pump and the air-liquid heat pump are activated.

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