TEST CHAMBER AND METHOD FOR ITS OPERATION

Abstract

A test chamber and a method for conditioning air in which the test chamber comprises a temperature-insulated test space, which is closable to an environment and serves to receive test material, and a temperature control device for controlling the test space in temperature, a temperature ranging from 40 C. to +180 C. being generable within the test space by the temperature control device. The temperature control device comprises a cooling apparatus having a first and second cooling cycle, the first cooling cycle having a first refrigerant, a first heat exchanger, a first compressor, a first condenser and a first expansion element, the first refrigerant being a hydrocarbon or a refrigerant mixture made of hydrocarbons. The second cooling cycle has a heat transfer medium, a second heat exchanger in the test space and a pump, the second cooling cycle being coupled to the first cooling cycle by the first heat exchanger.

Claims

1. A test chamber for conditioning air, in particular a climate chamber or the like, the test chamber comprising a temperature-insulated test space, which is closable to an environment and serves for receiving test material, and a temperature control device for controlling the test space in temperature, a temperature ranging from 40 C. to +180 C. being generable within the test space by the temperature control device, the temperature control device comprising a cooling apparatus having a first cooling cycle and a second cooling cycle, the first cooling cycle having a first refrigerant, a first heat exchanger, a first compressor, a first condenser and a first expansion element, the first refrigerant being a hydrocarbon or a refrigerant mixture made of hydrocarbons, wherein the second cooling cycle is made of a heat transfer medium, a second heat exchanger in the test space and a pump, the second cooling cycle being coupled to the first cooling cycle by the first heat exchanger.

2. The test chamber according to claim 1, wherein the first refrigerant is inflammable and the heat transfer medium is nonflammable.

3. The test chamber according to claim 1, wherein the first refrigerant is free of fluorinated hydrocarbons.

4. The test chamber according to claim 1, a storage apparatus for the heat transfer medium is disposed in the second cooling cycle.

5. The test chamber according to claim 1, wherein the cooling apparatus has another cooling cycle having another refrigerant, another compressor , another condenser and another expansion element, the other cooling cycle being coupled to the first condenser of the first cooling cycle by another heat exchanger.

6. The test chamber according to claim 5, wherein the other cooling cycle has another bypass having a third heat exchanger and a third expansion element, the other bypass being connected downstream of the other condenser and upstream of the other expansion element as well as downstream of the other heat exchanger and upstream of the other compressor, more refrigerant being able to be dosed in the other heat exchanger via the third expansion element, the second cooling cycle being coupled to the third heat exchanger of the other cooling cycle.

7. The test chamber according to claim 6, wherein the third heat exchanger is connected in the second cooling cycle downstream of the first heat exchanger and upstream of the second heat exchanger.

8. The test chamber according to claim 1. wherein a first bypass is designed having at least one first magnet valve in the first cooling cycle, the first bypass being connected downstream of the first compressor and upstream of the first condenser as well as downstream of the first expansion element and upstream of the first heat exchanger, first refrigerant being able to be dosed such via the first magnet valve that a temperature of the first refrigerant is able to be increased at the first heat exchanger.

9. The test chamber according to claim 1, wherein the temperature control device has a heating apparatus having a heater and a thermal heat exchanger.

10. The test chamber according to claim 1, wherein the temperature control device comprises a regulator having at least one temperature sensor in the second cooling cycle, at least one valve apparatus being able to be actuated in the second cooling cycle by the regulator as a function of a measured temperature.

11. The test chamber according to claim 10, wherein the second cooling cycle has a second bypass having the valve apparatus, the second bypass being connected downstream of the first heat exchanger and upstream of the second heat exchanger as well as downstream of the second heat exchanger and upstream of the pump, the heat transfer medium being able to be dosed in such a manner via the valve apparatus that the second heat exchanger is able to be bridged by the second bypass.

12. The test chamber according to claim 10, wherein the valve apparatus has a second magnet valve downstream of the first heat exchanger and upstream of the second heat exchanger and another magnet valve or a differential pressure regulator in the second bypass.

13. The test chamber according to claim 10, wherein the valve apparatus is formed having a three-way valve, which is disposed downstream of the second heat exchanger and upstream of the pump in the second cooling cycle, the second bypass being connected to the three-way valve.

14. The test chamber according to claim 1, wherein the test chamber comprises a detector having at least one gas sensor and a ventilation installation in an engine room of the test chamber separated from the test space in an airtight manner, the first cooling cycle being disposed entirely in the engine room.

15. A method for conditioning air in a temperature-insulated test space of a test chamber, in particular a climate chamber or the like, the test space being closable with respect to an environment and serving to receive test material, a temperature ranging from 40 C. to +180 C. being generated within the test space by a temperature control device of the test chamber, a temperature being generated within the test space by a cooling apparatus of the temperature control device having a first cooling cycle and a second cooling cycle, the first cooling cycle having a first refrigerant, a first heat exchanger, a first compressor, a first condenser and a first expansion element, the first refrigerant being a hydrocarbon or a refrigerant mixture made of hydrocarbons, wherein the second cooling cycle is made of a heat transfer medium, a second heat exchanger in the test space and a pump, the second cooling cycle being coupled to the first cooling cycle by the first heat exchanger, the heat transfer medium being circulated in the second cooling cycle by the pump.

16. The method according to claim 15, wherein the heat transfer medium is circulated in the second cooling cycle without phase changes.

17. The method according to claim 15, wherein a valve apparatus is actuated in the second cooling cycle as a function of a measured temperature by regulator of the temperature control device having at least one temperature sensor in the second cooling cycle, the heat transfer medium being circulated in the second cooling cycle via the second heat exchanger and/or a second bypass by the valve device.

18. The method according to claim 17, wherein the heat transfer medium is circulated via the second bypass until a target temperature of the heat transfer medium has been reached, the heat transfer medium being circulated via the second heat exchanger when the target temperature has been reached.

19. The method according to claim 17, wherein a revolution speed of the pump is regulated by the regulator.

20. The method according to claim 17, wherein upon reaching a target temperature of the heat transfer medium, the first compressor is switched off by the regulator, the heat transfer medium being circulated in the second cooling cycle and the second heat exchanger via a storage apparatus for the heat transfer medium, and/or the second cooling cycle being coupled to a third heat exchanger of another cooling cycle, to another refrigerant, to another compressor, to another condenser and to a third expansion element, the heat transfer medium being cooled by the third heat exchanger.

21. The method according to claim 15, wherein first refrigerant is dosed in such a manner via a first magnet valve by a first bypass in the first cooling cycle having at least one first magnet valve, which is connected downstream of the first compressor and upstream of the first condenser as well as downstream of the first expansion element and upstream of the first heat exchanger that a temperature of the first refrigerant is increased at the first heat exchanger.

Description

[0031] In the following, preferred embodiments of the invention are described in further detail with reference to the attached drawings.

[0032] FIG. 1 shows a circuit diagram of a first embodiment of a cooling apparatus;

[0033] FIG. 2 shows a circuit diagram of a second embodiment of a cooling apparatus;

[0034] FIG. 3 shows a circuit diagram of a third embodiment of a cooling apparatus;

[0035] FIG. 4 shows a circuit diagram of a fourth embodiment of a cooling apparatus;

[0036] FIG. 5 shows a circuit diagram of a fifth embodiment of a cooling apparatus;

[0037] FIG. 6 shows a circuit diagram of a sixth embodiment of a cooling apparatus;

[0038] FIG. 7 shows a circuit diagram of a seventh embodiment of a cooling apparatus;

[0039] FIG. 8 shows a circuit diagram of an eighth embodiment of a cooling apparatus;

[0040] FIG. 9 shows a circuit diagram of a ninth embodiment of a cooling apparatus;

[0041] FIG. 10 shows a circuit diagram of a tenth embodiment of a cooling apparatus;

[0042] FIG. 11 shows a schematic cut view of a test chamber;

[0043] FIG. 12 shows a perspective partial view of the test chamber from FIG. 11.

[0044] FIG. 1 shows a test chamber (not shown) by means of a schematic circuit diagram. Cooling apparatus 10 comprises a first cooling cycle 11 and a second cooling cycle 12. The first cooling cycle has a first refrigerant, a first heat exchanger 13, a first compressor 14, a first condenser 15 and a first expansion element 16. The first refrigerant is a hydrocarbon and/or a refrigerant mixture made of hydrocarbons. Second cooling cycle 12 comprises a heat transfer medium, a second heat exchanger 17, which is disposed in a test space (not shown), and a pump 18. Furthermore, second cooling cycle 12 comprises a storage apparatus 19 and a valve apparatus 20. Valve apparatus 20 is formed having a second bypass 21 in this instance. Second bypass 21 is connected to second cooling cycle 12 downstream of first heat exchanger 13 and upstream of second heat exchanger 17 as well as downstream of second heat exchanger 17 and upstream of pump 18. Valve apparatus 20 comprises a second magnet valve 22 downstream of first heat exchanger 13 and of the connection of second bypass 21 and another magnet valve 23 in second bypass 21. By means of first cooling cycle 11, the first refrigerant can now be conveyed, cooled and compressed via first compressor 14 and first condenser 15. The first refrigerant can then be expanded in first heat exchanger 13 via first expansion element 16 so that the heat transfer medium is cooled in first heat exchanger 13. In this context, the heat transfer medium is conveyed and/or circulated by pump 18 in second cooling cycle 12, the heat transfer medium, depending on the temperature requirement of a regulator (not shown) of the test chamber, can flow via second heat exchanger 17 and a temperature in the test space can be influenced and/or lowered via second magnet valve 22 and further magnet valve 23.

[0045] FIG. 2 shows a cooling apparatus 24, in which, in contrast to the cooling apparatus of FIG. 1, a valve apparatus 25 having a differential pressure regulator 26 is formed in second bypass 21. Depending on the open state of second magnet valve 22, the heat transfer medium can flow via differential pressure regulator 26 and/or via second bypass 21. Valve apparatus 26 can thus be produced particularly inexpensively.

[0046] FIG. 3 shows a cooling apparatus 27, which, in contrast to the cooling apparatus of FIG. 1, is designed having a valve apparatus 28. Valve apparatus 28 is designed having a three-way valve 29, which is connected to second bypass 21 downstream of second heat exchanger 17 and upstream of pump 18 and/or storage apparatus 19. Via three-way valve 29, second heat exchanger 17 can be optimally supplied with the heat transfer medium.

[0047] FIG. 4 shows a cooling apparatus 30, in which, in contrast to the cooling apparatus of FIG. 1, a first bypass 31 having a first magnet valve 32 is formed in first cooling cycle 11. First bypass 31 is connected downstream of compressor 14 and upstream of condenser 15 as well as downstream of first expansion element 16 and upstream of first heat exchanger 13. Via first magnet valve 32, first refrigerant can be dosed such that a temperature of the first refrigerant at first heat exchanger 13 is increased. For this purpose, first expansion element 16 is closed. Thus it becomes possible for the hot gas and/or first refrigerant to enter first heat exchanger 13 from first compressor 14 via first bypass 31 and to reach first compressor 14 again from there. This allows reaching a temperature of up to 90 C. at first heat exchanger 13, for example. This allows heating the heat transfer medium at first heat exchanger 14, when it is advantageous.

[0048] FIG. 5 shows a cooling apparatus 33, which, in contrast to the cooling apparatus of FIG. 1, has another cooling cycle 34. Further cooling cycle 34 is designed having another refrigerant, another compressor 35, another compressor 36 and another expansion element 37. In this context, further cooling cycle 34 is coupled to first cooling cycle 11 via another heat exchanger 38. Further heat exchanger 34 thus corresponds to the first condenser of first cooling cycle 11 and/or fulfills its function. By coupling cooling cycles 11 and 34, an even lower temperature can be generated at first heat exchanger 13.

[0049] FIG. 6 shows a cooling apparatus 33, which, in contrast to the cooling apparatus of FIG. 5, has the valve apparatus of the cooling apparatus of FIG. 2.

[0050] FIG. 7 shows a cooling apparatus 40, which, in contrast to the cooling apparatus of FIG. 5, has the valve apparatus of the cooling apparatus of FIG. 3.

[0051] FIG. 8 shows a cooling apparatus 41, which, in contrast to the cooling apparatus of FIG. 5, has another bypass 42. Further bypass 42 is formed having a third heat exchanger 43 and a third expansion element 44. Furthermore, a non-return valve 42 is disposed in further bypass 42. Further bypass 42 is connected to further cooling cycle 34 downstream of further condenser 36 and upstream of further expansion element 37 as well as to further cooling cycle 34 downstream of further heat exchanger 38 and upstream of further compressor 35. Via third expansion element 44, further refrigerant can be dosed in further heat exchanger 43 when further expansion element 37 is closed. A reflux of further refrigerants in third heat exchanger 43 can be prevented by non-return valve 45 when third expansion element 44 is closed and further expansion element 37 is open. Further, second cooling cycle 12 is coupled to further cooling cycle 34 via third heat exchanger 43. Third heat exchanger 43 is connected downstream of first heat exchanger 13 and upstream of second heat exchanger 17 in second cooling cycle 12. Provided very low temperatures are not required at second heat exchanger 17, first cooling cycle 11 can be circumvented by means of further bypass 42 and the heat transfer medium can be cooled solely via further cooling cycle 34 and/or further bypass 42.

[0052] FIG. 9 shows a cooling apparatus 46, which, in contrast to the cooling apparatus of FIG. 8, has the valve apparatus shown in FIG. 2.

[0053] FIG. 10 shows a cooling apparatus 47, which, in contrast to the cooling apparatus of FIG. 8, has the valve apparatus shown in FIG. 3.

[0054] FIGS. 11 and 12 show a schematic drawing of a test chamber 48 having a casing 49, within which a test space 50 and an engine room 51 are formed. A second heat exchanger 52 of a cooling cycle (not shown) is disposed in test space 50. Openings 53 and 54 are formed in engine room 51 for venting engine room 51. Furthermore, a first compressor 55 and a first condenser 56 of a first cooling cycle (not shown) are disposed in engine room 51 (shown schematically). A gas sensor 58 of a detector (not shown) is disposed at a bottom 57 of engine room 51. In addition, a ventilation installation 59 is provided in engine room 51. Ventilation installation 59 comprises a fan motor 60, a fan 61 and an exhaust tube 62. For this purpose, exhaust tube 62 extends outside of casing 49. In the event that gas sensor 58 should detect leaking hydrocarbon in engine room 51, ventilation installation 59 is activated, by means of which engine room 51 is vented.