小型制冷系统制冷剂充注量的试验研究

摘要

Charge inventory is a very important aspect amongst all physical system performance impactions.In existing system modeling tools,charge inventory is difficult to calculateaccuratly due to complexities such as effective internal volume,void frac-tion model in two phase region.This work uses Quick Control Valve Technique (QCVT),testing a 2kW heat pump unit (inclu-ding round-tube fin condenser and evaporator)and a 25kW cooling only unit (including round-tube fin evaporator and microchan-nel condenser)to get refrigerant charge in evaporator and condenser at varies system running conditions.The test results show good reliability to further investigation.Refrigerant mass distribution in the system is highly related to the type of heat exchanger and its internal volume,and the reduction of condenser internal volume will introduce performance sensibility to condition change. The test results are qualified for evaluating of performance and void fraction models in system modeling.%制冷剂充注量是制冷系统中影响系统性能的关键物理因素之一。在目前的仿真模型中，由于两相区有效面积计算和空泡系数模型选择的复杂性，很难对换热器中的制冷剂充注量进行准确的计算。本文使用快速关断技术（QCVT）试验测试方法，选用一台2kW 小型热泵家用机（含有翅片管蒸发器和冷凝器）和一台25kW 单冷轻型商用机（含有微通道冷凝器和翅片管蒸发器），在不同的系统运行工况下，对换热器中的制冷剂质量进行测试。试验结果表明，数据可靠性较好。制冷剂质量在系统中的分布与换热器的类型及内容积大小有很大关系，冷凝器内容积小的系统对工况变化的敏感度更高。测试结果对仿真模型的性能和空泡系数模型验证有指导意义。