Temperature chamber and method

Abstract

A temperature chamber for conditioning air includes a temperature-insulated space which receives test material, and a temperature control device for controlling the temperature of the test space. The temperature control device allows a temperature in a range of −50° C. to +180° C. to be established within the space, and has a cooling device including a cooling circuit with a refrigerant, a heat exchanger, a compressor, a condenser, and an expansion element. A jet device is connected to a low-pressure side of the cooling circuit downstream of the heat exchanger and upstream of the compressor, a first bypass is connected to a high-pressure side of the cooling circuit downstream of the compressor, and the refrigerant is suppliable to the jet device from the high-pressure side via the first bypass as a driving fluid.

Claims

1. A temperature chamber for conditioning air, in particular a test chamber or the like, comprising a temperature-insulated space which can be closed off from the surroundings and which serves to receive test material and a temperature control device for controlling the temperature of the space, the temperature control device allowing a temperature in a temperature range of −50° C. to +180° C. to be established within the space, the temperature control device having a cooling device comprising a cooling circuit with a refrigerant, a heat exchanger, a compressor, a condenser, and an expansion element, wherein a jet device is connected to a low-pressure side of the cooling circuit downstream of the heat exchanger and upstream of the compressor, a first bypass being connected to a high-pressure side of the cooling circuit downstream of the compressor, the refrigerant being suppliable to the jet device from the high-pressure side via the first bypass as a driving fluid, wherein the first bypass is connected to the high-pressure side of the cooling circuit upstream of the condenser.

2. The temperature chamber according to claim 1, wherein the jet device has a drive nozzle, which is connected to the first bypass, and a mixing chamber, the driving fluid being introduced into the mixing chamber in the flow direction of the cooling circuit via the drive nozzle, the mixing chamber forming a conduit section of the cooling circuit of the low-pressure side.

3. The temperature chamber according to claim 1, wherein the first bypass is provided with at least one first control element.

4. The temperature chamber according to claim 1, wherein the first bypass is connected to the high-pressure side of the cooling circuit downstream of the condenser.

5. The temperature chamber according to claim 1, wherein another bypass having at least one other control element is formed in the cooling circuit, the other bypass being connected to the cooling circuit upstream of the jet device and downstream of the heat exchanger and upstream of the compressor and downstream of the jet device and bypassing the jet device.

6. The temperature chamber according to claim 1, wherein the cooling circuit has an internal heat exchanger, the internal heat exchanger being connected to the high-pressure side of the cooling circuit upstream of the expansion element and downstream of the condenser and to the low-pressure side of the cooling circuit upstream of the compressor and downstream of the heat exchanger, the refrigerant of the high-pressure side being coolable by the refrigerant of the low-pressure side by means of the internal heat exchanger.

7. The temperature chamber according to claim 6, wherein the internal heat exchanger is connected to the low-pressure side upstream of the compressor and downstream of the jet device.

8. The temperature chamber according to claim 6, wherein the internal heat exchanger is connected to the low-pressure side upstream of the jet device and downstream of the heat exchanger.

9. The temperature chamber according to claim 1, wherein the heat exchanger is disposed in the space.

10. The temperature chamber according to claim 1, wherein the heat exchanger forms a cascade heat exchanger for another cooling circuit of the cooling device.

11. The temperature chamber according to claim 1, wherein the condenser is realized as a cascade heat exchanger of another cooling circuit of the cooling device.

12. The temperature chamber according to claim 1, wherein the expansion element and/or a control element has a throttle element and a magnetic valve, refrigerant being meterable via the throttle element and the magnetic valve.

13. A temperature chamber for conditioning air, in particular a test chamber or the like, comprising a temperature-insulated space which can be closed off from the surroundings and which serves to receive test material and a temperature control device for controlling the temperature of the space, the temperature control device allowing a temperature in a temperature range of −50° C. to +180° C. to be established within the space, the temperature control device having a cooling device comprising a cooling circuit with a refrigerant, a heat exchanger, a compressor, a condenser, and an expansion element, wherein a jet device is connected to a low-pressure side of the cooling circuit downstream of the heat exchanger and upstream of the compressor, a first bypass being connected to a high-pressure side of the cooling circuit downstream of the compressor, the refrigerant being suppliable to the jet device from the high-pressure side via the first bypass as a driving fluid, and wherein a second bypass having at least one second control element is formed in the cooling circuit, the second bypass being connected to the cooling circuit upstream of the expansion element and downstream of the condenser and bypassing the expansion element, refrigerant being meterable via the second control element in such a manner that a suction gas temperature and/or a suction gas pressure of the refrigerant on the low-pressure side of the cooling circuit is controllable upstream of the compressor.

14. The temperature chamber according claim 13, wherein the second bypass is connected to the cooling circuit downstream of the heat exchanger and upstream of the jet device.

15. The temperature chamber according to claim 13, wherein the second bypass is connected to the first bypass.

16. A method for conditioning air in a temperature-insulated space of a temperature chamber, in particular a test chamber or the like, which can be closed off from the surroundings and which serves to receive test material, a temperature in a temperature range of −50° C. to +180° C. being established within the space by means of a cooling device of a temperature control device of the temperature chamber, comprising a cooling circuit with a refrigerant, a heat exchanger, a compressor, a condenser and an expansion element, wherein a jet device is connected to a low-pressure side of the cooling circuit downstream of the heat exchanger and upstream of the compressor, the refrigerant being supplied to the jet device from the high-pressure side as a driving fluid via a first bypass connected to a high-pressure side of the cooling circuit downstream of the compressor, and wherein a second bypass having at least one second control element is formed in the cooling circuit, the second bypass being connected to the cooling circuit upstream of the expansion element and downstream of the condenser and bypassing the expansion element, refrigerant being meterable via the second control element in such a manner that a suction gas temperature and/or a suction gas pressure of the refrigerant on the low-pressure side of the cooling circuit is controllable upstream of the compressor.

17. The method according to claim 16, wherein the driving fluid is introduced into a mixing chamber of the jet device in the flow direction of the cooling circuit via a drive nozzle of the jet device, said drive nozzle being connected to the first bypass, the refrigerant being aspirated into the mixing chamber as a suction fluid upstream of the jet device and being ejected from the mixing chamber downstream of the jet device at a higher pressure than that of the suction fluid.

Description

(1) Hereinafter, preferred embodiments of the disclosure will be explained in more detail with reference to the accompanying drawings.

(2) FIG. 1 is a schematic illustration of a first embodiment of a cooling device;

(3) FIG. 2 is a schematic illustration of a second embodiment of a cooling device;

(4) FIG. 3 is a schematic illustration of a third embodiment of a cooling device.

(5) FIG. 4 is a schematic illustration of a fourth embodiment of a cooling device;

(6) FIG. 5 is a schematic illustration of a fifth embodiment of a cooling device;

(7) FIG. 6 is a schematic illustration of a sixth embodiment of a cooling device;

(8) FIG. 7 is a schematic illustration of a seventh embodiment of a cooling device;

(9) FIG. 8 is a schematic illustration of an eighth embodiment of a cooling device.

(10) FIG. 1 shows a first embodiment of a cooling device 10 of a temperature chamber or test chamber (not shown). Cooling device 10 comprises a cooling circuit 11 with a refrigerant, a heat exchanger 12, a compressor 13, a condenser 14 and an expansion element 15. Heat exchanger 12 is disposed in a space or test space (not shown) of the test chamber. In the space, a fan 16 for circulating air is provided at heat exchanger 12. Furthermore, cooling circuit 11 has a high-pressure side 17, a low-pressure side 18 and a compensation tank 19.

(11) The refrigerant is aspirated upstream of compressor 13 and compressed, thus increasing a pressure on high-pressure side 17 compared to low-pressure side 18. Downstream of compressor 13, the refrigerant is liquefied using condenser 14. The refrigerant is decompressed at expansion element 15 and at least partially or fully evaporated in heat exchanger 12. Thereafter, the wet steam of the refrigerant returns to compressor 13. Downstream of heat exchanger 12 and upstream of compressor 13 in the flow direction of the refrigerant, a jet device 20 is connected to a conduit section 21 upstream of compressor 13. Furthermore, a to first bypass 22, via which refrigerant from high-pressure side 17 is supplied to jet device 20 as a driving fluid, is connected downstream of compressor 13 and upstream of condenser 14. First bypass 22 is connected to a drive nozzle (not shown) of jet device 20, via which the refrigerant is introduced into a mixing chamber (not shown) of jet device 20 as a driving fluid in such a manner that refrigerant from a conduit section 23 is aspirated into cooling circuit 11 upstream of jet device 20 and accelerated. This causes an increase in pressure in conduit section 21 compared to the pressure in conduit section 23. Advantageously, this allows compressor 13, which may be a compressor device, to be operated in an energetically favorable output range.

(12) A second bypass 24 having at least one second control element 25 is integrated in cooling circuit 11, second bypass 24 being connected to cooling circuit 11 upstream of expansion element 15 and downstream of condenser 14 in the flow direction of the refrigerant. Furthermore, second bypass 24 is connected to cooling circuit 11 downstream of heat exchanger 12 and upstream of jet device 20 in the flow direction of the refrigerant, second bypass 24 thus bypassing expansion element 15. Via second control element 25, refrigerant can now be metered in such a manner that a suction gas temperature and/or a suction gas pressure of the refrigerant can be controlled on low-pressure side 18 of cooling circuit 11 upstream of compressor 13.

(13) FIG. 2 shows a second embodiment of a cooling device 26, which differs from the cooling device of FIG. 1 in that a first control element 27 is disposed or connected in first bypass 22. Via first control element 27, a drive of jet device 20 can be controlled. This also allows an evaporation pressure achievable in heat exchanger 12 to be influenced, for example.

(14) FIG. 3 shows an embodiment of a cooling device 28 which differs from the cooling device shown in FIG. 2 in that a second bypass 29 is not connected directly to low-pressure side 18 but to first bypass 22. Consequently, second bypass 29 is connected to first bypass 22 downstream of first control element 27 and upstream of jet device 20 in the flow direction of the refrigerant. The refrigerant flowing via second control element 25 of second bypass 29 in a controlled manner can also be used as a driving fluid for jet device 20 in that case. This increase of a driving mass flow of jet device 20 enables a further increase in pressure in conduit section 21.

(15) FIG. 4 shows an embodiment of a cooling device 30 which differs from the cooling device of FIG. 3 in that another bypass 31 is provided. Other bypass 31 is provided with another control element 32 and connected to thus-formed cooling circuit 33 upstream of jet device 20 and downstream of heat exchanger 12 in the flow direction of the refrigerant. Furthermore, other bypass 31 is connected to cooling circuit 33 upstream of compressor 13 and downstream of jet device 20. If second control element 25 and first control element 27 are closed, no driving mass flow for jet device 20 can be provided, which means that no increase in pressure can be generated upstream of compressor 13 using jet device 20. Jet device 20, which is not driven in that case, causes an undesirable pressure drop upstream of compressor 13. Third bypass 31 can now be used to bypass jet device 20 so as to enlarge a conduit cross-section and to prevent this pressure drop.

(16) FIG. 5 shows another embodiment of a cooling device 34, which differs from the cooling device of FIG. 2 in that an internal heat exchanger 36 is connected in thus-formed cooling circuit 35. In particular, internal heat exchanger 36 is connected to high-pressure side 17 upstream of expansion element 15 and downstream of condenser 14 and to low-pressure side 18 upstream of jet device 20 and downstream of heat exchanger 12 in the flow direction of the refrigerant. On high-pressure side 17, refrigerant flowing toward expansion element 15 can be cooled be means of internal heat exchanger 36. Cooling may take place by the refrigerant on low-pressure side 18 being re-evaporated in internal heat exchanger 36. In this case, in particular, a refrigerant having a particularly wide temperature glide can be used.

(17) FIG. 6 shows an alternative embodiment of a cooling device 37, which differs from the cooling device of FIG. 5 in that internal heat exchanger 36 is connected to low-pressure side 18 between jet device 20 and compressor 13.

(18) FIG. 7 shows an embodiment of a cooling device 38 which differs from the cooling device of FIG. 1 in that a first bypass 39 is connected downstream of condenser 14. Via first bypass 39, cold and liquid refrigerant can be supplied to jet device 20 as a driving fluid from high-pressure side 17.

(19) FIG. 8 shows an embodiment of a cooling device 40 which differs from the cooling device of FIG. 7 in that a first control element 41 is disposed or connected in first bypass 39.