Double-temperature refrigerating system and control method thereof

Abstract

The invention provides a double-temperature refrigerating system and a control method thereof. The refrigerating system comprises two evaporators, two heat exchange fans, a compressor, a condenser, agas-liquid separator, a cascade heat exchanger, a solenoid valve and three electronic expansion valves. The refrigerating system adopts a binary non-azeotropic mixing working medium and ensures that arefrigerating agent with the high low-boiling-point working medium flows into the low-temperature evaporator through the internal auto-cascade technology, so that the evaporation pressure is increased, the pressure ratio and power consumption of the compressor are reduced, and the energy efficiency of the system is improved. The invention further provides the control method of the refrigerating system. Through the control method, the three working modes of independent refrigerating of the high-temperature evaporator, independent refrigerating of the low-temperature evaporator and simultaneousrefrigerating of the two evaporators can be realized, and the application scene is more flexible. A traditional series double-temperature refrigerating system has the disadvantages of large compressor pressure ratio, high exhaust temperature, low energy efficiency and the like. Through the double-temperature refrigerating system and the control method thereof, the problems can be effectively solved.

Description

technical field [0001] The invention relates to the technical field of refrigeration of refrigerators and freezers, in particular to a dual-temperature refrigeration system and a control method thereof. Background technique [0002] Dual-temperature refrigeration equipment is widely used in household and commercial fields, such as refrigerators, dual-temperature freezers, etc. As a widely used general-purpose device, the optimization of its structure and performance has always been a research hotspot. Due to the development of refrigerant replacement technology and the trend of applying environmentally friendly refrigerants, the use of mixture refrigerants in single-stage vapor compression refrigeration cycle systems has become one of the research topics and technology development approaches that have attracted widespread attention at home and abroad. [0003] However, when zeotropic refrigerants such as R600a / R290, R290 / R170 and R290 / CO are directly used in a conventional ...

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Problems solved by technology

[0003] However, when zeotropic refrigerants such as R600a / R290, R290 / R170 and R290 / CO are directly used in a conventional single-stage vapor compression refrigeration cycle system 2 etc. Due to the phase change temperature glide characteristics of zeotropic mixture refrigerants, the refrigeration efficiency of the cycle system (that is, the cycle coefficient of performance COP) is often low, which restricts its practical application.

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