环保型CO_2跨临界制冷系统

Environmental Friendly Trans-Critical CO_2 Refrigerant System

自然工质CO2 是一种不对臭氧层产生破坏、具有很小的温室效应系数的制冷剂 .本文介绍了跨临界CO2 制冷系统的构成和控制特点 ,分析了影响其性能的主要因素 ,设计了CO2 制冷压缩机、换热器、节流机构的关键技术 .影响CO2 制冷压缩机性能的主要因素是泄漏 ,影响压缩机以及所有循环系统配件安全性的主要因素是其结构强度 .CO2 制冷系统换热器设计的趋势是采用高流量密度的小管径和微通道换热器 ,这有利于提高换热系数和承受高压 .节流阀把高压侧压力节流到蒸发压力 ,同时控制高压侧压力并使其随气体冷却器出口温度的变化而变化 ,CO2 制冷系统调节特性与传统制冷系统不同 .

The ecological refrigerant CO 2 is a working fluid that does not contribute to ozone depletion or global warming greenhouse.The trans critical CO 2 refrigerant system and the characteristics of control methods are introduced.The key technique for designing the main components,such as compressor,gas cooler,and throttling mechanism is analysed. The leakage of the cylinder is the major factor affecting the indicated process of CO 2 compressors. The structure strength of compressor and all the components are important to the security of the whole system. The heat exchangers are designed for high refrigerant mass flux and are made with small diameter tubes or extruded flat microchannel tubes,which can increase the heat transfer coefficient and endure higher pressure. By throttles,the high pressure is dropped down to evaporator pressure,and changed with the refrigerant temperature at the gas cooler, the regulation characteristics of the system are different from traditional system.