Test chamber and method

Abstract

A method for conditioning a fluid in a temperature-insulated test space and a test space of a test chamber for receiving test materials. A cascading cooling device creates a particular temperature range within the test space, and the cooling device has a first cooling circuit comprising a cascading heat exchanger, a first compressor, a condenser and a first expanding element, and a second cooling circuit comprising a heat exchanger, a second compressor, the cascading heat exchanger and a second expanding element. The cascading heat exchanger is cooled by the first cooling circuit, the heat exchanger is cooled by a bypass passing through the heat exchanger and bridging the cascading heat exchanger, the first compressor is turned off, and a first refrigerant is conducted and condensed in a gaseous state in the cascading heat exchanger on a low-pressure side of the bypass.

1 . A test chamber for conditioning a fluid, particularly air, comprising a temperature-insulated test space ( 14 ), which is sealable against an environment, for receiving test materials and a temperature control device for controlling the temperature of the test space, a temperature ranging from −60° C. to +180° C. in temperature being able to be realized within the test space by means of the temperature control device, said temperature control device having a cascading cooling device ( 10 ) having a first cooling circuit ( 11 ) having a first refrigerant, a cascading heat exchanger ( 15 ), a first compressor ( 16 ), a condenser ( 17 ) and a first expanding element ( 18 ), and having a second cooling circuit ( 12 ) having a second refrigerant, a heat exchanger ( 13 ) arranged in the test space, a second compressor ( 27 ), the cascading heat exchanger and a second expanding element ( 28 ), said cascading heat exchanger being able to be cooled by means of the first cooling circuit, characterized in that the first cooling circuit is realized having a bypass ( 35 ) passing through the heat exchanger and bridging the cascading heat exchanger, said heat exchanger being able to be cooled by means of the first cooling circuit, and said temperature control device comprising an adjusting device by means of which the first compressor can be turned off and the first refrigerant being able to be conducted and condensed in a gaseous state in the cascading heat exchanger on a low-pressure side ( 22 ) of the bypass. 
     
     
         2 . The test chamber according to  claim 1 , characterized in that the first cooling circuit ( 11 ) is thermally coupled to the second cooling circuit ( 12 ) by means of the cascading heat exchanger ( 15 ). 
     
     
         3 . The test chamber according to  claim 1 , characterized in that the cascading heat exchanger ( 15 ) is formed by a plate heat exchanger whose primary side is connected to the first cooling circuit ( 11 ) and whose secondary side is connected to the second cooling circuit ( 12 ). 
     
     
         4 . The test chamber according to  claim 1 , characterized in that the bypass ( 35 ) is connected to a high-pressure side ( 21 ) of the first cooling circuit ( 11 ) in a flow direction upstream of the first expanding element ( 18 ) and downstream of the condenser ( 17 ) and to the low-pressure side ( 22 ) of the first cooling circuit in a flow direction upstream of the first compressor ( 16 ) and downstream of the cascading heat exchanger ( 15 ). 
     
     
         5 . The test chamber according to  claim 1 , characterized in that the temperature control device comprises a heating device having a heater and a heating heat exchanger in the test space ( 14 ).