小型双蒸发温度冷/热水机组的运行调节特性实验

Experiment on Operation and Regulation Characteristics of a Small Dual Evaporation Temperatures Water Chiller/Heater

本文针对中小型住宅或办公建筑在温湿度独立控制方面存在的不足,建立了一套基于双蒸发温度的新型冷/热水机组。实验研究了在改变压缩机频率(30~80 Hz)及高温与低温侧电子膨胀阀(EEV1、EEV2)开度(80%~100%、10%~50%)工况下系统的运行情况,记录供回水温度以及冷冻水流量并对高低温侧冷量进行分析,从而研究该冷/热水机组的运行调节特性。结果表明:变频制冷和制热工况下,机组制冷(制热)量均与压缩机频率呈正比关系;制冷工况下,当EEV2开度小于30%时,随着EEV1开度的增大,机组高低温侧制冷量和总制冷量呈下降趋势;EEV1开度固定时,随着EEV2开度的增大,机组高温侧制冷量基本保持恒定,低温侧制冷量和总制冷量呈先上升后下降的趋势,在EEV2开度约为30%时出现最大值,此时机组的除湿能力也达到最大。

Considering the shortcomings of temperature and humidity-independent control in small and medium-scale residential and office buildings,a novel water chiller/heater based on dual evaporation temperatures was developed.The operating conditions of the unit were investigated through experiments in which the compressor speed and valve opening were varied.The compressor speed was varied from 30-80 Hz and the high and low-temperature sides of the electronic expansion valves(EEV1 and EEV2)were opened from 80%-100%and from 10%-50%,respectively.The experimental results were analyzed to reveal the operational and regulatory characteristics of the unit.The results showed that the cooling and heating capacities of the unit were proportional to the compressor speed in the cooling and heating modes.In the cooling mode,when the EEV2 opening was<30%,the cooling capacity at the high and low temperature sides and the total cooling capacity of the unit decreased as EEV1 opening increased.When the EEV1 opening was fixed and the EEV2 opening increased,the cooling capacity on the high-temperature side was largely constant.The cooling capacity on the low-temperature side and the total cooling capacity first increased and then decreased,reaching a maximum with EEV2 opening at 30%.The highest low-temperature cooling capacity suggests a better dehumidification capacity.