Test chamber

Abstract

The invention relates to a test chamber (10) for conditioning air, comprising a test space (12) for holding test material, which test space, with respect to surroundings, can be closed off and is temperature-isolated, and comprising a temperature-control device (11) for the temperature control of the test space. A temperature in a temperature range of -80 DEG C to +180 DEG C, preferably -100 DEG Cto +200 DEG C, can be formed within the test space by means of the temperature-control device. The temperature-control device has a cooling device (16). Said cooling device has a cooling circuit (17)having a refrigerant, a heat exchanger (18), which is arranged in the test space, a compressor (19), a condenser (20), and an expansion element (21). The refrigerant is a nearly azeotropic and / or zeotropic refrigerant mixture of a mass fraction of carbon dioxide and a mass fraction of at least one of the components ethane, ethylene, hexafluoroethane, pentafluoroethane, monofluoroethane, 1,1-difluoroethylene, fluoromethane, and / or propane and / or xenon, wherein the refrigerant has a global warming potential<sb / >, with respect to 20 years, of < 3000, preferably < 500, especially preferably < 10.

Description

technical field [0001] The present invention relates to a test chamber for conditioning air, comprising a test space for receiving test material and which can be isolated from the surrounding environment and is temperature insulated, and a temperature control device for controlling the temperature of the test space, the temperature control device allowing Establish a temperature in the test space within the temperature range of -80°C to +180°C, preferably -100°C to +200°C, the temperature control device has a cooling device, the cooling device includes a cooling circuit with refrigerant, set in the test space heat exchangers, compressors, condensers, and expansion elements. Background technique [0002] Such test chambers are generally used for testing physical and / or chemical properties of objects, in particular devices. For example, temperature test cabinets or climate test cabinets are known in which a temperature range of -50° C. to +180° C. can be established. In a cl...

AI Technical Summary

Problems solved by technology

[0005] However, carbon dioxide is not a very suitable refrigerant for the temperature range used in the test chamber, as carbon dioxide having a triple point at -56.6°C makes it impossible to use pure carbon dioxide at temperatures below -55°C

For example, a mixture of carbon dioxide and nitrous oxide can be used as a refrigerant at temperatures as low as -70°C, but nitrous oxide destroys the ozone layer

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