蒸发器出口两相时制冷系统动态特性模拟

Dynamic Simulation of Refrigeration System with Flooded Evaporator

建立了以集总参数法为基础,以换热器为主要研究对象的制冷系统动态仿真模型。模型中,制冷系统中的蒸发器、冷凝器、电子膨胀阀、压缩机等核心部件都利用能量、质量、动量等基本方程耦合建立了理论模型,并通过使用Mat-lab的Simulink模块完成整个循环的动态仿真。该模型可完成蒸发器两相出口等特殊工况的模拟,并解决了以往仿真中易出现的模型和算法振荡问题,在模拟两相出口时能够实现模型的平滑过渡。当该模型用于空调系统时,在系统参数突然变化的情况下,能够模拟系统相应的动态变化过程。经过试验验证,该模型在模拟蒸发器出口两相的特殊工况时也具备相当的准确性。

A dynamic simulation model for refrigeration system was proposed with lumped parameter method. The heat exchangers in the system is the primary objects of research in the model. The model consisted of four main component model of evaporator, condenser, electronical expansion valve and compressor which all models were modelled with lumped parameter method and the cycle simulation is assembled through Simulink in the software Matlab. The dynamic performance of refriferation system in abnormal condition can be carried out with the system model, such as the two-phase states at heat exchanger outlet. The switch oscillations with calculational methods and mathematical models occurred in preceding simulations do not come out in this model. The switching between models is an smooth progress without any singular point and breakpoint. When the model is applied in the sudden parameter change of air-conditioning system, the corresponding dynamic characteristics can be presented in the model. With the experiment validation, the simulation of two-phase outlet have veracity of a certain extent compared to the experimental data.