PRESSURE RELIEF ARRANGEMENT IN REFRIGERANT CIRCUITS

Abstract

A pressure relief arrangement in refrigerant circuits with one high-pressure side and one low-pressure side, which is characterized in that the high-pressure side is fluidically connected with the low-pressure side of the refrigerant circuit via an overpressure relief device, wherein the overpressure relief device causes pressure reduction of the overpressure in the case of overpressure on the high-pressure side and fluid flows from the high-pressure side to the low-pressure side of the refrigerant circuit.

Claims

1-16. (canceled)

17. A pressure relief arrangement in a refrigerant circuit comprising: a high-pressure side; and a low-pressure side, wherein the high-pressure side is fluidically connected with the low-pressure side of the refrigerant circuit via an overpressure relief device, wherein the overpressure relief device provides for pressure reduction of overpressure in case of an overpressure on the high-pressure side, and fluid flows from the high-pressure side to the low-pressure side of the refrigerant circuit.

18. The pressure relief arrangement according to claim 17, wherein the overpressure relief device connects one component of the refrigerant circuit with high pressure with another component of the refrigerant circuit with low pressure.

19. The pressure relief arrangement according to claim 17, wherein the overpressure relief device is arranged in a component of the refrigerant circuit, wherein fluid-carrying areas inside the component of the refrigerant circuit with fluid under high pressure are produced as the high-pressure side and fluid-carrying areas with fluid under low pressure as the low-pressure side, which are fluidically connected to one another via the overpressure relief device.

20. The pressure relief arrangement according to claim 17, wherein the overpressure relief device is arranged in a pressure relief channel between the high-pressure side and the low-pressure side of a compressor.

21. The pressure relief arrangement according to claim 20, wherein the pressure relief channel is produced inside a housing of the compressor or arranged in the housing of the compressor as a separate fluid line.

22. The pressure relief arrangement according to claim 21, wherein the overpressure relief device is integrated into the housing of the compressor from the inside, without passage to the outside.

23. The pressure relief arrangement according to claim 22, wherein the overpressure relief device is screwed into the housing from inside.

24. The pressure relief arrangement according to claim 21, wherein the overpressure relief device is integrated into the housing of the compressor from outside.

25. The pressure relief arrangement according to claim 24, wherein the overpressure relief device is screwed into the housing from outside.

26. The pressure relief arrangement according to claim 25, wherein the overpressure relief device exhibits two gaskets, wherein a metallic gasket seals externally towards the environment and an 0-ring internally.

27. The pressure relief arrangement according to claim 17, wherein the overpressure relief device is produced as a pressure relief valve, as a safety valve, or as a rupture disc.

28. The pressure relief arrangement according to claim 27, wherein the overpressure relief device is the pressure relief valve and exhibits a valve body, wherein an overflow channel runs axially in the valve body.

29. The pressure relief arrangement according to claim 17, wherein the overpressure relief device is produced in two stages, wherein a pressure equalization between the high-pressure side and the low-pressure side is performed internally in a first stage and a pressure equalization towards the environment is performed externally in a second stage.

30. The pressure relief arrangement according to claim 17, wherein the overpressure relief device is arranged in a heat exchanger with adjacent heat transfer modules for high pressure as a condenser and for low pressure as an evaporator at a separation wall between high pressure and low pressure in such a way that a fluidic connection is established between the high-pressure side and the low-pressure side when triggering pressure relief and the fluid flows under high pressure into the low-pressure side.

31. The pressure relief arrangement according to claim 30, wherein the overpressure relief device is arranged in a manifold/collector of the heat exchanger.

32. A method for superheat control of refrigerant circuits with flammable refrigerants, wherein the superheat AtE in case of high pressure at a compressor outlet is controlled in a range between 15 K and 20 K.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0034] Further details, features and advantages of embodiments of the invention result from the following description of examples of embodiment with reference to the corresponding drawings. The illustrations show the following:

[0035] FIG. 1: Partial cross-sectional view of the refrigerant compressor with pressure relief arrangement

[0036] FIG. 2: Cross-sectional view of the heat exchanger with pressure relief arrangement, and

[0037] FIG. 3: Log Ph diagram of the superheat.

DESCRIPTION OF AN EMBODIMENT

[0038] FIG. 1 shows a partial cross-sectional view of a refrigerant compressor with a pressure relief arrangement according to the invention. It was foregone to represent the complete refrigerant compressor, and only the part that comprises the pressure relief arrangement is shown. A compressor 5 according to the principle of spiral compressors is represented as the refrigerant compressor. Compressors of this type are also called scroll compressors or spiral compressors. According to its functionality, a compressor 5 exhibits a high-pressure side 1 of the refrigerant, and a low-pressure side 2. The task of a compressor 5 is to compress the refrigerant vapor to high pressure by using the low pressure from the low-pressure side 2 in accordance with the mechanical principle of operation and then to convey it from the compressor 5 into the refrigerant circuit on the high-pressure side 1. Thus, ultimately, the pressure relief arrangement consists of the combination of an overpressure relief device 3 that is produced in the represented example of embodiment as the pressure relief valve 7, and a pressure relief channel 4 within which the overpressure relief device 3 is arranged. The pressure relief channel 4 effectively establishes a short-circuit connection from the high-pressure side 1 to the low-pressure side 2 in case of overpressure and in case of triggering of the overpressure relief device 3. Then, to avoid problems and destruction with resulting escape of the refrigerant from the circuit, the refrigerant flows at high pressure in a controlled manner via the pressure relief channel 4 to the low-pressure side 2 after triggering of the pressure relief valve 7, and the high-pressure side 1 of the refrigerant circuit is protected from mechanical destruction due to overpressure thanks to the performed pressure equalization. In the embodiment shown here, the pressure relief valve is screwed into the housing 6 of the compressor 5 from the outside. To this end, the valve body 9 exhibits an external thread on the cylindrical perimeter, which is indicated in the figure and corresponds with an internal thread in the housing 6 of the compressor 5. The pressure relief valve 7 is screwed into the housing 6 from the outside and is sealed externally by way of a gasket that is not specified in detail here and produced as an 0-ring in the example of embodiment. The valve body 9 exhibits an axial through-hole that releases a flow path for the fluid from the pressure relief channel 4 via the valve body 9 of the pressure relief valve 7 towards the low-pressure side 2 in the compressor 5 in case of pressure relief. The flow path for the refrigerant inside the valve body 9 is also called overflow channel 10. When the pressure relief valve 7 is triggered, the flow path is switched from the high-pressure side 1 via the pressure relief channel 4 to the pressure relief valve 7 and through its valve body 9 in the overflow channel 10 to continue the pressure relief channel 4 towards the low-pressure side 2.

[0039] Alternatively to the represented embodiment of embedding the pressure relief valve 7 in the design inside the compressor 5, the most varied designs and implementations of this safety principle can be realized. For example, to prevent risks arising from leaks, the overpressure relief device 3 can be integrated into the housing 6 of the compressor 5 from the inside so that no external sealing is required due to the externally closed housing 6.

[0040] FIG. 2 shows a cross-sectional view of a heat exchanger with pressure relief arrangement, wherein the heat exchanger 11 comprises heat transfer modules that are produced as the condenser 12 and evaporator 13 inside an integrated heat exchanger 11. The condenser 12 is arranged on the high-pressure side 1 of the refrigerant circuit and is physically separated from the evaporator 13 by an adjacent separation wall 14 that is installed on the low-pressure side 2 of the refrigerant circuit. In the separation wall 14, an overpressure relief device 3 is produced as a so-called rupture disc 8 that at a specified overpressure releases a flow path in the separation wall 14 from the condenser 12 to the evaporator 13 so that refrigerant can escape with high pressure through the overpressure relief device 3 at a specified place and at a specified pressure and thus protect the heat exchanger 11 from destruction. According to the shown preferred embodiment, the overpressure relief device 3 is arranged in the separation wall 14 in the area of the manifold/collector 15, resulting in a very efficient and concentrated flow and thus a very fast pressure equalization between high-pressure side 1 and low-pressure side 2. Thanks to the positioning in the manifold/collector 15, a special contribution is made to risk mitigation.

[0041] FIG. 3 shows a log Ph diagram of a refrigerant circuit as an example. In the case of low pressure, the superheat as the temperature difference AtSdT is as measured according to the state of the art for the superheat control at the evaporator outlet. In the case of high pressure, the superheat is represented as the temperature difference in the range between 15 and 25 K with AtE according to the invention. The superheat is preferably controlled in the range between 15 and 20 K A with tE according to the invention. The superheat control allows much more stable control at high pressure.

[0042] The invention relates to a pressure relief arrangement in refrigerant circuits, in particular in mobile refrigerant systems and heat pumps.