A dual-temperature refrigeration system and its control method

Abstract

A dual-temperature refrigeration system and its control method, the refrigeration system includes two evaporators, two heat exchange fans, a compressor, a condenser, a gas-liquid separator, a cascade heat exchanger, a solenoid valve and three electronic Expansion valve; the refrigeration system uses binary non-azeotropic mixed working fluid, and uses internal self-cascade technology to ensure that the refrigerant with a large content of low-boiling point working fluid enters the low-temperature evaporator, thereby increasing the evaporation pressure and reducing the pressure ratio and work of the compressor. The energy consumption of the system is improved, and the control method of the refrigeration system is proposed, which can realize three working modes: high-temperature evaporator individual cooling, low-temperature evaporator individual cooling, and two evaporator simultaneous cooling, and the application scenarios are more flexible; traditional series dual-temperature refrigeration The system has disadvantages such as large compressor pressure ratio, high exhaust temperature, and low energy efficiency, and the invention can effectively solve these problems.

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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