基于模型的二氧化碳微通道气体冷却器性能分析

MODELING AND PERFORMANCE ANALYSIS OF CARBONDIOXIDE MICROCHANNEL GAS COOLER

建立了跨临界二氧化碳制冷装置中对整个系统性能有很大影响的重要部件微通道气体冷却器的分布参数模型 ,用于指导优化设计 ,模型中考虑了二氧化碳和空气的分布特性 .通过比较仿真结果和试验数据验证了模型的正确性 .基于该模型对气体冷却器结构参数进行了敏感性分析 ,指出了气体冷却器结构参数的合理变化范围 .

Microchannel gas cooler is an important component of transcritical carbon dioxide refrigerating equipment, and of great significance to system performance. However, few investigations have been made on this new type of heat exchanger. A steady-state distributed-parameter model is established, in which distributed properties of both carbon dioxide and air are considered. Through comparing simulation results with experimental results from literatures of American Air Conditioning and Refrigerating Center, the model is accepted with an error within 13%. Then this model is used for sensitivity analysis of gas cooler performance to its configuration parameters, such as microchannel diameter, number of microchannels, number of tubes, number of processes. According the simulation results, it is suggested that the microchannel diameter should be within 0.7 to 1 mm, and there should be 2 to 4 processes.