Simulation of cryogenic thermocompressor performance with non-isothermal gas volumes

UDC 621.57

Simulation of cryogenic thermocompressor performance with non-isothermal gas volumes

Blagin E. V., Dovgyallo A.I., Uglanov D.A.

This article deals with thermocompressor performance calculation. This device is based on the thermomechanical energy conversation principle, which includes energy transformation from heat to pressure energy without intermediate transfer to mechanical energy. Authors suggest using a thermocompressor with cryogenic working fluid which allows using the heat of the environment as an upper heat source. In this case energy will be consumed only for displacer drive. The calculation algorithm is suggested taking temperature change in gas volumes into account. It was found that gas temperature changes significantly depending on working frequency. There is an optimal regime with maximal compressor output. The frequency of optimal regime is about 1 Hz for given conditions. The coefficient of the mechanical energy conversation was used as a criterion for energy efficiency estimation. The coefficient varies from 4.5 at frequency of 0.2 Hz to 1 at frequency of 4 Hz. Thermocompressor output drop is caused by its overheating and, consequently, choking. For neutralization of the choking effect it is suggested to intensify a heat exchange between the wall and the gas in the cold volume as well as to use a mesh with higher porosity.

Keywords: thermomechanical converters, thermocompressors, nonisothermality, delivery rate, mechanical energy conversion coefficient

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