再热除湿单元式空调机的设计改进及实验研究

Improved Design and Experimental Investigation of a Unitary Dehumidification Unit with Hot Gas Reheat

为了满足在不同空调负荷下能够除湿的同时输送舒适的空气温度和相对湿度,设计并搭建了一种新型的可调节再热除湿系统,优化制冷模式和除湿再热两种模式的制冷剂管理以及改进再热运行开度区间,并对比分析了不同再热盘管方案。实验结果表明:新式微通道再热盘管应用于风冷单元式空调机组能够更好地平衡制冷与除湿再热模式对充注量的需求;在除湿再热模式额定工况下的能效EER提高了17%;除湿能力增加了6%;制冷剂通过三通阀流向再热盘管的可调节开度范围从20%~70%提升至15%~85%,增大了空气侧再热温升的调节范围,额定除湿再热工况再热温升从8.3~14.4℃的调节区间增至6.1~19.4℃。既能提升再热可调节运行范围,增大除湿能力又更加节能。

To deliver comfortable conditioned air by reducing humidity levels while enhancing comfort levels in an air space under varied load conditions,an improved design for fully modulating dehumidification with a hot gas reheat system was developed.By managing the charge balance between the cooling and reheat modes,the modulation operating map for the reheat opening was expanded.Different microchannel heat exchanger(MCHE)reheat coil patterns and solutions were analyzed.The test results showed that an air-resourced unitary unit equipped with this novel MCHE reheat system solution improved the balance between the refrigerant charge requirements and the cooling and reheat modes.Under rating conditions,the energy efficiency ratio(EER)in the reheat mode increased by 17%,and water condensate removal through dehumidification was enhanced by 6%.The modulating valve reheat port opening range could be increased from a baseline of 20%-70%to 15%-85%.For the rated reheat dehumidification condition,the reheat temperature rise modulating range increased from 8.3-14.4℃to 6.1-19.4℃.This innovative solution was proven to achieve a wider adjustable operating map that improved dehumidification capacity and power conservation.