【摘要】 采用试验方法研究了风量变化对中大型风冷热泵机组结霜工况性能的影响。研究发现,迎面风量的变化对V型换热器最早结霜位置几乎没有影响,最早结霜位置总在换热器弯头连接段附近,风量的变化只是影响管壁温度的高低,与直管段相比,弯管段制冷剂压损较大,管壁温度较低,利于霜晶形成;迎面风量降低导致系统蒸发温度降低,致使结霜速度加快,直接造成机组稳定工作时间缩短;适当提高风机转速具有抑制结霜,减少除霜次数,有效提高机组运行性能的作用;消除V型换热器较高位置和较低位置支路出口带液是解决振荡的根本办法。更多还原

【Abstract】 The experiments for different airflow were conducted on an air-to-water heat pump unit and discussed.The results indicate that the airflow flux has little effect on the location of the earliest frosting.This position is always near the bend tube.Compared with the straight part,the bend tube has more refrigerant pressure losses,which leads to lower tube surface temperature.Therefore,frost crystals form earlier at the bend tube position.It was also found that the process of frosting is quickened with airflow decreasing.The unit stable work time becomes longer with increasing fan speed in some extent.Furthermore,the defrosting times can be reduced.It is an essential method to solve the hunting problem by eliminating the liquid state of refrigerant branches outlets at the upper position and the lower position of V type heat exchanger.更多还原