Test chamber and control method

Abstract

To provide a test chamber for conditioning air and a method for operating the test chamber, which enable inexpensive production and inexpensive operation.SOLUTION: The cooling system comprises a cooling device (42) and a heat exchanger (40) arranged in the test space, wherein the cooling device is realized having a cooling circuit with a refrigerant, a compressor, a condenser, and an expansion element, wherein the heat exchanger is connected to the cooling circuit, the refrigerant is carbon dioxide, the test chamber has a control device for adjusting a temperature in the test space, and the cooling system is realized with a second cooling device (43, 44, 45) having a second cooling circuit (48, 49, 50) with the refrigerant, a second compressor, a second condenser, and a second expansion element, wherein the heat exchanger is connected to the second cooling circuit, and wherein the cooling device is controllable by the control device as a function of the temperature in the test space.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a test chamber, in particular a climate chamber for conditioning air, in particular a temperature-controlled chamber, climate chamber, etc., and to a method for conditioning the air in a test space of the test chamber, the test chamber comprising a test space for receiving a test material, the test space being sealable and insulated against the environment, and a temperature control device for controlling the temperature of the test space, in which a temperature in the range of -20°C to +180°C can be established by the temperature control device, the temperature control device comprising a heating device and a cooling system, the cooling system comprising a heat exchanger arranged in the cooling device and in the test space, the cooling device being realised with a cooling circuit using a refrigerant, a compressor, a condenser and an expansion valve, the heat exchanger being connected to the cooling circuit, the refrigerant being carbon dioxide, and the test chamber having a control device for regulating the temperature in the test space. [Background technology]

[0002] This type of test chamber is regularly used to test the physical and / or chemical properties of objects, particularly devices. For example, test cabinets or climate test cabinets are known, the internal temperature of which can be set between -70°C and +180°C. In the case of climate test cabinets, desired climate conditions can additionally be set, to which devices or test materials are exposed for a predetermined time. The temperature of the test space containing the test material to be tested is regularly controlled in an air circulation duct within the test space. The air circulation duct forms an air handling space within the test space, in which a heat exchanger is arranged for heating and / or cooling the air flowing through the air circulation duct or test space. A fan or ventilator draws air into the test space and directs it to the heat exchanger within the air circulation duct. In this way, the test material can be temperature-controlled or exposed to desired temperature changes. In this case, the temperature can be varied, for example, between the maximum and minimum temperatures of the test chamber, during the test period. A test chamber of this type is known, for example, from Patent Document 1.

[0003] Refrigerants used in refrigeration circuits should have a fairly low CO2 equivalent value, i.e., the relative greenhouse potential or global warming potential (GWP) should be as low as possible to avoid indirect adverse effects on the environment if the refrigerant is released. Therefore, carbon dioxide (CO2) is also known to be used as a pure substance refrigerant. Carbon dioxide is available at low cost, is non-flammable, and has a GWP of 1, making it essentially environmentally neutral. The freezing point or triple point of carbon dioxide is -56.6°C, so temperatures lower than this cannot be achieved using carbon dioxide alone.

[0004] Carbon dioxide as a refrigerant has a very high volumetric cooling capacity, and even when using compressors with very low stroke volume flows, very high cooling capacities can be provided by the refrigeration circuit. In addition, the pressure range of a refrigeration circuit using carbon dioxide as a refrigerant is very high in transcritical operation (up to 120 bar (12 MPa)), which is why the components required to form the refrigeration circuit are quite expensive. Due to the associated high pressures in the internal volumes of large refrigeration circuits, special safety requirements must additionally be met.

[0005] Load fluctuations occur as a function of temperature changes in the test space, and the compressor is activated or deactivated as necessary by the control device. Compressor deactivation occurs whenever cooling of the test space is required or when very high temperatures, for example, up to +180°C, are established. Second, if the temperature in the test space is to be lowered to, for example, -20°C during the test cycle, a very large refrigeration capacity of the cooling system and / or cooling device is required, especially if the temperature is to be lowered within a short period of time. Furthermore, the temperature in the test space may be lowered slowly or kept constant at a low level during the test cycle. For this purpose, the compressor must also be operated continuously, which is difficult due to the sizing of the cooling system according to the maximum required refrigeration capacity and requires additional plant-specific efforts. In this case, storage vessels, internal heat exchangers, bypass sections, etc. may be integrated into the cooling circuit. Furthermore, in this case, the energy consumption of the cooling device and / or cooling system is always higher than in the case of a relatively low refrigeration capacity.

[0006] Since test chambers are used for different applications, they may be differently sized to receive specific products and thus may be realized with different refrigeration capacities. As a result, test chambers must be produced at least in part individually for each application, especially if energy-efficient operation of the test chamber is to be guaranteed. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] European Patent Application Publication No. 0344397 Summary of the Invention [Problem to be solved by the invention]

[0008] SUMMARY OF THE INVENTION It is therefore an object of the present invention to propose a test chamber for conditioning air and a method for operating the test chamber that allows for cheap production and cheap operation. [Means for solving the problem]

[0009] This object is achieved by a test chamber having the features of claim 1, by a use of a module set having the features of claim 13 and by a method having the features of claim 14.

[0010] The test chamber for conditioning air, in particular a temperature-controlled chamber, climate chamber, etc., according to the present invention comprises a test space for receiving a test material, the test space being sealable and insulated against the environment, and a temperature control device for controlling the temperature of the test material, in which a temperature in the range of -20°C to +180°C can be established by the temperature control device, the temperature control device comprising a heating device and a cooling system, the cooling system comprising a heat exchanger arranged in the cooling device and in the test space. The cooling device is realized to have a cooling circuit using a refrigerant, a compressor, a condenser, and an expansion valve, and the heat exchanger is connected to the cooling circuit, the refrigerant being carbon dioxide. The test chamber has a control device for regulating the temperature in the test space. The cooling system is realized to have a second cooling device, the second cooling device having a second cooling circuit using a refrigerant, a second compressor, a second condenser, and a second expansion valve, and the heat exchanger is connected to the second cooling circuit, and the cooling device is controllable by the control device as a function of the temperature in the test space.

[0011] According to the present invention, the intention is that the cooling system of the test chamber comprises at least two cooling devices. Both cooling devices are realized so as to each have a cooling circuit using a refrigerant, a compressor, a condenser, and an expansion valve. Carbon dioxide is used as the refrigerant in both cooling circuits. Both cooling circuits are connected to a heat exchanger located in the test space. In this example, the cooling circuits are not connected to each other. The control device is realized so that the cooling devices can be controlled by the control device as a function of the temperature in the test space. For example, if a high refrigeration capacity is required in the heat exchanger to establish a specific temperature in the test space, the control device can operate the cooling devices and / or their respective compressors in parallel and / or simultaneously. If only a low refrigeration capacity is required in the heat exchanger in the test space, the control device only needs to operate one of the cooling devices and / or their compressors and shut down the other cooling device and / or its compressor. The refrigeration or cooling capacity (W) is determined by the area (m ) of the heat exchanger. 2 ) and the heat transfer coefficient (W / m 2 × K) and the temperature difference (K).

[0012] Compared to a single cooling device in a test chamber, the internal volume of each cooling circuit in a test chamber according to the present invention is relatively small. Therefore, in this example, only a very low amount of refrigerant needs to circulate in each cooling circuit, and there is no longer any need to provide structural measures, such as storage containers, in the cooling circuit to reduce the refrigeration capacity of the heat exchanger in the test space. Therefore, each cooling circuit can be designed in an overall technically simpler manner. In contrast, in cooling circuits known in the art, the refrigerant must flow through the entire internal volume of the cooling circuit to ensure the transport of oil for lubricating the compressor, even when the load is partial and / or the required refrigeration capacity is low. Therefore, the refrigeration capacity of the cooling circuit cannot be easily reduced by reducing the volumetric flow rate of the refrigerant.

[0013] Although it is true that two cooling devices are installed when producing the test chamber, they are designed in a less complicated way. Because the internal volume per cooling device is proportionally smaller, the ratio of the refrigerant pressures in the cooling circuits and the internal volume change, resulting in fewer cooling circuit safety requirements that must be met. Furthermore, rather than a leak in the cooling circuit shutting down the entire cooling system, the cooling device can continue to operate with the cooling circuit still intact. Furthermore, in this example, only a significantly smaller, single compressor circulating a smaller amount of refrigerant needs to be operated, resulting in energy savings. Overall, energy and costs can be saved over a longer operating period of the test chamber.

[0014] The lines of the cooling circuits of each cooling device may run independently through the heat exchanger. In this case, the cooling circuits are not materially connected to each other and are realized separately from each other. In this case, the lines of the cooling circuits may all be connected to the heat exchanger, but run separately from each other within the heat exchanger. The lines may be arranged within the heat exchanger so that they run through different sections of the heat exchanger, realizing areas and / or partial surface areas of the heat exchanger that can be allocated to each cooling circuit. Alternatively, the lines may run in parallel through the entire heat exchanger, for example, so that the entire surface of the heat exchanger can be used by each cooling device.

[0015] The cooling system can be realized with other cooling devices, each with a different refrigerant circuit, a different compressor, a different condenser, and a different expansion valve, and the heat exchanger is connected to the other cooling circuits. Consequently, the cooling system can have three, four, five, six, or more cooling devices, all connected to the heat exchanger in their respective cooling circuits. This allows combining multiple cooling devices depending on the desired cooling capacity of the test chamber, so that the desired cooling capacity can be achieved. Furthermore, in this case, the control device can operate only one cooling device, two or more cooling devices, or all cooling devices as a function of temperature and / or capacity requirements, as needed.

[0016] The heat exchanger can be realized with a single exchanger body. In this case, each line of the cooling circuit can run through the exchanger body. In this case, depending on the arrangement of the lines within the exchanger body, the surface area of ​​the exchanger body can be used, which is effective for fully or partially controlling the temperature in each line of each cooling circuit, allowing dynamic changes in the temperature in the test space to occur even when the temperature difference between the exchanger body and the test space is quite small. It is essential that the exchanger body is connected to each cooling circuit immediately downstream of the respective expansion valve so that only the refrigerant flowing through the expansion valve travels through the exchanger body. In this context, the exchanger body can be understood as a body that can consist of one or more parts and through which the refrigerant flows. This also includes a line structure with fins for improved heat transfer. In this case, the fins, together with the line structure, form the exchanger body. In this case, the exchanger body has a surface area effective for heat transfer.

[0017] Each cooling device can be realized as an assembly having at least a support unit with a compressor, a condenser, and an expansion valve arranged thereon. The assembly can be configured to allow for modular design of the cooling system from the assembly. The support unit can be a frame, plate, housing, etc., configured so that the compressor, condenser, and expansion valve can simply be mounted on the support unit and connected via a cooling circuit. Furthermore, multiple valves, a condenser fan, a bypass section of the cooling circuit, an internal heat exchanger, electrical connections, sensors, and other electrical and / or electronic components can be arranged on the support unit. The modular assembly can be realized as a cooling device that functions independently, separate from the heat exchanger, without requiring any additional attachments. In this case, the cooling system can be particularly simple, consisting of at least two cooling devices and / or assemblies. In this case, it is only necessary to connect the assemblies and / or respective lines of the cooling circuit to the heat exchanger to produce the cooling system.

[0018] The test chamber can be realized with a machine room spatially separated from the test space, and the cooling devices can be arranged in the machine room. If each cooling device is realized as an assembly, the cooling devices can be arranged in the machine room particularly easily. In this case, the test chamber can accommodate the cooling devices in the housing of the test chamber. In this case, the machine room can already be designed in such a way that a certain number of cooling devices can be arranged in the machine room. Depending on the desired refrigeration capacity of the test chamber, the machine room can be equipped with cooling devices accordingly. In this case, it is also possible to leave some free space in the machine room, which can be filled by subsequent installation of cooling devices if a higher refrigeration capacity is desired at a later date.

[0019] The cooling devices can be of the same design or different designs. Depending on the desired refrigeration capacity or the use of the test chamber, cooling devices with the same refrigeration capacity, which may be the same or different, can be combined to form a cooling system. If at least three cooling devices are provided, two can be of the same design and one can be, for example, differently designed. The same design of cooling devices with different refrigeration capacities, or additionally, a modular design, means that it is no longer necessary to configure and produce cooling devices individually for each application of the test chamber. Advantageously, a large number of cooling devices can be prefabricated and stored in a warehouse, allowing them to be particularly easily installed and delivered when a customer orders a test chamber. For this purpose, it is only necessary to arrange existing cooling devices together to achieve the desired cooling system. Furthermore, these cooling devices can be produced in a standardized manner in series production, which is particularly cost-effective.

[0020] The cooling devices can be realized with refrigeration capacities ranging from 1 to 20 kW. For example, one cooling device can have a refrigeration capacity of 1 kW and a second cooling device can have a refrigeration capacity of 20 kW, and together they form a cooling system. Cooling devices with different refrigeration capacities within the above range can also be used. In this case, the cooling device with the lower refrigeration capacity can be operated when only very low refrigeration capacity is required, for example, to maintain a constant temperature in the test space. The cooling device with the higher refrigeration capacity and / or both cooling devices can be operated when rapid temperature changes from high to low temperatures are performed in the test space.

[0021] The cooling circuit can be realized to include at least a low-pressure compressor and a high-pressure compressor downstream of the low-pressure compressor in the refrigerant flow direction. In principle, all cooling devices of the cooling system can be realized in this manner. In this case, the cooling device can be configured as a so-called booster system. In this case, in the cooling circuit of the cooling device, the high-pressure compressor is connected in series downstream of the low-pressure compressor, so that the refrigerant is compressed in stages: first using the low-pressure compressor, and then using the high-pressure compressor. Alternatively, the compressor can be a single two-stage compressor. Temperature changes in the test space can cause fluctuations in load requirements during the test cycle. In this case, the low-pressure compressor can be operated together with the high-pressure compressor, or the high-pressure compressor can be operated alone. This is possible when the cooling circuit has a valve device that can direct the refrigerant to either the low-pressure compressor or the high-pressure compressor. The valve device can be realized, for example, by a three-way valve that can supply the refrigerant to either the low-pressure compressor or the high-pressure compressor. The valve device can be easily operated by a control device. This allows the individual cooling devices of the cooling system to be varied within the constraints of their respective refrigeration capacities. Overall, the cooling system can therefore be much better adjusted to the refrigeration capacity requirements.

[0022] The temperature control device may enable a temperature in the test space to be established in the temperature range of -40°C to +180°C, preferably -55°C to +180°C.

[0023] Pure carbon dioxide (CO2) can be used as the refrigerant. Pure carbon dioxide has a GWP of 1, is non-flammable, non-hazardous, and available at low cost. Furthermore, carbon dioxide is either a pure substance or azeotropic, which allows for advantageous operation of the test chamber. Advantageously, carbon dioxide is used as the refrigerant for each cooling circuit. In this case, each cooling circuit can be operated in a thermodynamically transcritical or subcritical state. Depending on the cooling load requirements within the test space, the operating state can be changed using a control device.

[0024] The temperature control device may include a heating device in the test space that includes a heater and a heating heat exchanger. For example, the heating device may be an electric resistance heater that heats the heating heat exchanger so that an increase in temperature in the test space is possible through the heating heat exchanger. If the heat exchanger and the heating heat exchanger can be controlled and / or adjusted in a targeted manner by the control device to cool or heat the air circulating in the test space, the temperature control device can establish a temperature in the test space within the temperature range specified above.

[0025] The present invention also contemplates a method for using a modular set having at least three cooling devices to produce a test chamber according to the invention, the modular set comprising at least two cooling devices of the same and / or identical design and at least one cooling device of a different design, the at least two cooling devices being selected from the modular set for producing the test chamber. The modular set may also include a plurality of additional cooling devices of the same or different design. The modular set allows for a selection from these cooling devices of the same and / or different design to realize the cooling system of the test chamber according to the invention. The selection can be performed to achieve a desired refrigeration capacity. Furthermore, the selection can take into account the extent to which a significantly larger refrigeration capacity is required for faster temperature changes and a significantly smaller refrigeration capacity is required to maintain a constant temperature in the test space during the test sequence. Further advantageous embodiments of the method are apparent from the characterizing remarks of the dependent claims which refer to claim 1 of the device.

[0026] The method for operating a test chamber, in particular a temperature-controlled chamber, a climate chamber, etc., for conditioning air according to the present invention comprises the steps of: the test chamber having a test space for receiving a test material, the test space being sealable and thermally insulated against the environment; the temperature of the test space being controlled by a temperature control device of the test chamber; the temperature control device establishing a temperature in the test space ranging from -20°C to +180°C; the temperature control device comprising a heating device and a cooling system; the cooling system comprising a heat exchanger arranged between the cooling device and the test space; and a heat exchanger, wherein the cooling device is realized to have a cooling circuit using a refrigerant, a compressor, a condenser, and an expansion valve, the heat exchanger is connected to the cooling circuit, the refrigerant is carbon dioxide, a control device of the test chamber regulates the temperature in the test space, the cooling system is realized to have a second cooling device, the second cooling device having a second cooling circuit using a refrigerant, a second compressor, a second condenser, and a second expansion valve, the heat exchanger is connected to the second cooling circuit, the cooling device being controlled by the control device as a function of the temperature in the test space. For advantages of the method according to the invention, please refer to the description of the advantages of the test chamber according to the invention.

[0027] The control device can operate each cooling device according to the refrigeration capacity required to achieve the temperature in the test space. For this purpose, the control device can operate the cooling devices together or on their own. In this case, at least one cooling device can be stopped by the control device. In this case, energy can be saved since less refrigerant has to be circulated overall.

[0028] Further embodiments of the method are evident from the characterizing recitations of the dependent claims which refer back to claim 1 of the device.

[0029] In the following, preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings. [Brief explanation of the drawings]

[0030] [Figure 1] FIG. 1 shows a schematic diagram of one embodiment of a cooling device. [Figure 2] FIG. 2 shows a perspective view of another embodiment of a cooling device. [Figure 3] FIG. 3 shows a schematic diagram of the test chamber with the cooling system. DETAILED DESCRIPTION OF THE INVENTION

[0031] FIG. 1 shows a possible embodiment of a cooling device 10 of a cooling system of a test chamber (not shown in this example). In this case, the cooling system has at least two cooling devices (not shown in this example). The cooling device 10 comprises a cooling circuit 11 using carbon dioxide (CO2) as a refrigerant, a heat exchanger 12, a low-pressure compressor 13, a high-pressure compressor 14, a condenser 15, and an expansion valve 16. In this example, the heat exchanger 12 is part of the cooling system (not shown) of the test chamber. In this example, the condenser 15 is configured in the form of a heat exchanger or gas cooler and is cooled by a heat transfer medium such as air or water. The heat exchanger 12 is arranged in an air handling duct (not shown in this example) of the test space of the test chamber so that the air in the test space circulated through the air handling duct can be cooled by the heat exchanger 12. Furthermore, the cooling circuit 11 has a low-pressure side portion 17, an intermediate-pressure side portion 18, and a high-pressure side portion 19. In the low-pressure side portion 17, the pressure of the refrigerant is relatively lower than that in the intermediate-pressure side portion 18. In the intermediate-pressure side portion 18, the pressure of the refrigerant is relatively lower than that in the high-pressure side portion 19.

[0032] The refrigeration circuit 11 further comprises an internal heat exchanger 20 downstream in the refrigerant flow direction and an intermediate-pressure bypass section 21 upstream of the expansion valve 16. The intermediate-pressure bypass section 21 terminates downstream of the low-pressure compressor 13 and upstream of the high-pressure compressor 14. An intermediate-pressure valve 22 is arranged in the intermediate-pressure bypass section 21. In this case, the intermediate-pressure valve 22 is connected upstream of the internal heat exchanger 20. Here, the essentially partially liquid refrigerant is conducted upstream of the condenser 15 through the high-pressure side section 19 of the internal heat exchanger 20 and, if necessary, metered into the intermediate-pressure side section 18 of the internal heat exchanger 20 via the intermediate-pressure valve 22. In this case, the refrigerant in the high-pressure side section 19 is subcooled to an extent that an even lower temperature can be established in the expansion valve 16 and / or the heat exchanger 12. At the same time, the refrigerant flowing through the intermediate-pressure bypass section 21 can be used to maintain a significantly lower intake gas temperature for the high-pressure compressor 14.

[0033] Furthermore, the cooling circuit 11 comprises a second bypass section 23 having a second bypass valve 24. The second bypass section 23 is connected to the cooling circuit 11 downstream of the internal heat exchanger 20 and upstream of the expansion valve 16 in the refrigerant flow direction, and downstream of the heat exchanger 12 and upstream of the low-pressure compressor 13. The second bypass valve 24 allows the liquid refrigerant to pass through the expansion valve 16 and the heat exchanger 12 to the low-pressure section 17. This makes it possible to adjust the intake gas temperature and / or intake gas pressure in the low-pressure section 17 upstream of the low-pressure compressor 13. The cooling device 10 can be regulated by control devices (not shown) and sensors of the test chamber, in particular by pressure and temperature sensors located in the cooling circuit 11.

[0034] FIG. 2 shows a perspective view of a cooling device 25, which is an embodiment of the cooling device of FIG. 1. In this example, the cooling device 25 also comprises a cooling circuit 26 using a refrigerant, in particular carbon dioxide, a compressor 27, a condenser 28 and / or a gas cooler, and an expansion valve 29. The cooling device 25 is part of a cooling system of a test chamber (not shown in this example). In this case, the cooling system also comprises at least one second cooling device (not shown in this example). The cooling device 25 comprises an internal heat exchanger 30. Lines 31 and 32 serve to connect to a heat exchanger (not shown in this example) located in the test space of the test chamber. In this example, the cooling device 25 is realized as a modular assembly 33 with a support unit 34, in which the compressor 27, the condenser 28, the expansion valve 29, and the internal heat exchanger 30 are rigidly mounted on the support unit 34. The compressor 27 can also be realized by a low-pressure compressor and a high-pressure compressor. Thus, the assembly 33 can be pre-assembled in the form of an intermediate product. In this case, for integration in the test chamber it is only necessary to connect the assembly 33 via lines 31 and 32 to a heat exchanger (not shown in this example) of a cooling system.

[0035] 3 shows a schematic diagram of a test chamber 35 having a test space 36 tightly sealed against the environment 37. An air circulation duct 38 is realized in the test space 36, through which the air located in the test space 36 can be circulated. This is performed by a fan 39 in the air circulation duct 38. A heat exchanger 40 of a cooling system 41 is arranged in the air circulation duct 38. The cooling system 41 consists of cooling devices 42, 43, 44, and 45. The cooling devices 42, 43, 44, and 45 are arranged in a machine room 46 of the test chamber 35. However, they may also be arranged outside the machine room 46. Cooling circuits 47, 48, 49, and 50 of the cooling devices 42, 43, 44, and 45, respectively, are connected to the heat exchanger 40 via lines 51.

[0036] The heat exchanger 40 is realized by an exchanger body 52. ​​Lines 51 or cooling circuits 47, 48, 49, 50 each run through the exchanger body 52 independently and materially separated from one another. Depending on which refrigeration capacity is required in the test space 36, the cooling devices 42, 43, 44, and / or 45 can then be operated or deactivated by a control device (not shown in this example) of the test chamber. The heat exchanger 40 is then partially or completely cooled. The cooling devices 42, 43, 44, and 45 can be designed identically and / or differently from one another and have the same or different refrigeration capacities. Depending on the refrigeration capacity requirement in the test space 36, the control device can operate or deactivate the appropriate cooling device 42, 43, 44, or 45, respectively.

Claims

1. A test chamber (35), in particular a temperature-controlled chamber, climate chamber, etc., for conditioning the atmosphere, said test chamber comprising a test space (36) for receiving a test material, said test space being sealable and thermally insulated against the environment (37), and a temperature control device for controlling the temperature of said test space, said temperature control device being capable of establishing a temperature in the test space in the range of -20°C to +180°C, said temperature control device The apparatus comprises a heating and cooling system (41), the cooling system comprising a cooling device (10, 25, 42, 43, 44, 45) and a heat exchanger (12, 40) arranged in the test space, the cooling device being realized to have a cooling circuit (11, 26, 47, 48, 49, 50) using a refrigerant, a compressor (13, 14, 27), a condenser (15, 28) and an expansion valve (16, 29), the heat exchanger being connected to the cooling circuit, the refrigerant being carbon dioxide (CO ２ ) wherein the test chamber has a controller for regulating the temperature within the test space, a second cooling device (10, 25, 42, 43, 44, 45) having a second cooling circuit (11, 26, 47, 48, 49, 50) using the refrigerant, a second compressor (13, 14, 27), a second condenser (15, 28), and a second expansion valve (16, 29), the heat exchanger being connected to the second cooling circuit, and the cooling device being controllable by the control device as a function of the temperature in the test space.

2. 2. A test chamber according to claim 1, characterized in that the lines (31, 32, 51) of the cooling circuits (11, 26, 47, 48, 49, 50) of each of the cooling devices (10, 25, 42, 43, 44, 45) run through the heat exchanger (12, 40) independently of one another.

3. 3. The test chamber according to claim 1 or 2, characterized in that the cooling system (41) is realized with another cooling device (10, 25, 42, 43, 44, 45) having another cooling circuit (11, 26, 47, 48, 49, 50) using the refrigerant, another compressor (13, 14, 27), another condenser (15, 28) and another expansion valve (16, 29), and the heat exchanger (12, 40) is connected to the other cooling circuit.

4. Test chamber according to any one of claims 1 to 3, characterized in that the heat exchanger (12, 40) is realized with a single exchanger body (52).

5. 5. A test chamber according to claim 1, wherein each cooling device (10, 25, 42, 43, 44, 45) is realized as an assembly (33) comprising at least a support unit (34) having a compressor (13, 14, 27) arranged thereon, a condenser (15, 28) and an expansion valve (16, 29).

6. 6. A test chamber according to claim 1, characterized in that the test chamber (35) is realized with a machine room (36) spatially separated from the test space (36), and the cooling device (10, 25, 42, 43, 44, 45) is arranged in the machine room.

7. 7. Test chamber according to any one of claims 1 to 6, characterized in that the cooling devices (10, 25, 42, 43, 44, 45) are of the same design or are designed differently from one another.

8. Test chamber according to any one of claims 1 to 7, characterized in that the cooling device (10, 25, 42, 43, 44, 45) is realized with a refrigeration capacity ranging from 1 to 20 kW.

9. 9. A test chamber according to any one of claims 1 to 8, characterized in that at least the cooling circuit (11, 26, 47, 48, 49, 50) is realised to have a low-pressure compressor (13) and a high-pressure compressor (14) downstream of the low-pressure compressor in the flow direction of the refrigerant.

10. 10. A test chamber according to any one of claims 1 to 9, characterized in that the temperature control device allows a temperature in the test space (36) to be established in the temperature range of -40°C to +180°C, preferably -55°C to +180°C.

11. Pure carbon dioxide (CO ２ 11. A test chamber according to claim 1, characterized in that a gas containing HCl is used as the coolant.

12. 12. A test chamber according to any one of the preceding claims, characterized in that the temperature control device comprises a heating device in the test space (36) which comprises a heater and a heating heat exchanger.

13. 13. A method of using a modular set having at least three cooling devices (10, 25, 42, 43, 44, 45) for producing a test chamber (35) according to any one of claims 1 to 12, wherein the modular set comprises at least two cooling devices of the same design and at least one cooling device of a different design, and wherein at least two cooling devices are selected from the modular set for producing the test chamber.

14. A method for operating a test chamber (35), in particular a temperature-controlled chamber, a climate chamber, etc., for conditioning the atmosphere, said test chamber having a test space (36) for receiving a test material, said test space being sealable and insulated against the environment (37), the temperature of said test space being controlled by a temperature control device of said test chamber, said temperature control device establishing a temperature in said test space in the range of -20°C to +180°C, said temperature control The device comprises a heating and cooling system (41), the cooling system comprising a cooling device (10, 25, 42, 43, 44, 45) and a heat exchanger (12, 40) arranged in the test space, the cooling device being realized to have a cooling circuit (11, 26, 47, 48, 49, 50) using a refrigerant, a compressor (13, 14, 27), a condenser (15, 28) and an expansion valve (16, 29), the heat exchanger being connected to the cooling circuit, the refrigerant being carbon dioxide (CO ２ ) wherein the test chamber controller regulates the temperature within the test space. the cooling system is realized to include a second cooling device (10, 25, 42, 43, 44, 45) having a second cooling circuit (11, 26, 47, 48, 49, 50) using the refrigerant, a second compressor (13, 14, 27), a second condenser (15, 28), and a second expansion valve (16, 29), the heat exchanger being connected to the second cooling circuit, and the cooling device being controlled by the control device as a function of the temperature in the test space.

15. 15. The method of claim 14, wherein the control device operates each of the cooling devices (10, 25, 42, 43, 44, 45) as a function of the refrigeration capacity required to achieve the temperature in the test space (36).

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