DEVELOPMENT OF LOW-TEMPERATURE REFRIGERATION UNIT OPERATING ON MIXTURE OF REFRIGERANTS
When designing refrigeration units with condensing pressure relative to the boiling pressure for more than eight, it is recommended to use a two-stage compression. This complicates the refrigeration unit circuit, increases capital and operating costs. The one-stage refrigeration unit circuit operating on a mixture of refrigerants allows obtaining low boiling point at high temperature condensation. For a more effective method of obtaining low temperatures, it is proposed to upgrade the one-stage refrigeration system. To ensure trouble-free operation hermetic reciprocating compressor of high reliability is chosen, mixture of refrigerants to be fueled, expansion tank and unit automation devices are changed. By means of low-temperature unit, operating on mixture of refrigerants it is possible to reach temperature in a chamber in the range of -40…-65°C. This unit has good performance: the lubricating oil is circulated in the system without accumulating in the cooling devices, and vapor sucked into the compressor has small overheat. The proposed one-stage compression refrigeration unit operating on mixture of refrigerants allows operating at high rates of condensing and evaporating pressure. The result is a lower boiling point in a one-stage compression, thereby reducing the capital and operating costs of the refrigeration unit as a whole.