Improved self-cascade refrigeration cycle system and control method thereof

Abstract

The invention discloses an improved self-cascading refrigeration cycle system and a control method thereof, which are applied to low-temperature systems such as low-temperature freezers, low-temperature refrigerators, medical low-temperature refrigeration instruments, etc. Compared with the traditional self-cascade system, the regenerator and throttle device are added between the condenser and thegas-liquid separator. The system can not only make the two fluids exchange heat more fully in the evaporative condenser, but also prevent the compressor from sucking in the liquid, raise the evaporative pressure of the whole system, reduce the pressure ratio of the compressor, and improve the efficiency of the compressor, so as to increase the refrigeration capacity of the system and improve theperformance of the circulating system. As such, that present invention has significant advantage over conventional self-cascade cycle using regenerator and throttle valves in front of the gas-liquid separator.

Description

technical field [0001] The invention belongs to the technical field of refrigeration and low temperature, and relates to a refrigeration cycle system and a control method thereof, in particular to a self-cascading refrigeration cycle system using a single compressor and a control method thereof. Background technique [0002] Self-cascading refrigeration systems are widely used in low-temperature freezers, low-temperature refrigerators, medical low-temperature freezing equipment and other fields. It has the characteristics of low cost, simple structure and rapid cooling; it uses mixed working fluid as the working fluid, and can realize low-temperature refrigeration in a wide temperature range. Especially in recent years, with the application of mixed refrigerants and the development of single-unit lubricating oil compression technology in the system, its characteristics have become more prominent. Therefore, the self-cascading cycle has relatively great practical value in th...

AI Technical Summary

Problems solved by technology

Therefore, the conventional self-cascading cycle still has a certain heat release capacity at the outlet of the condenser, and this part of the heat cannot be released to the environment due to the need to ensure a reasonable ratio of high boiling point working fluid to low boiling point working medium

On the other hand, the temperature glide problem in the self-cascading circulation system will lead to low evaporation pressure and high compressor pressure ratio

The way to increase the evaporating pressure is to properly reduce the dryness of the evaporator outlet, which will cause the compressor to suck liquid and affect the service life of the compressor

Images