降低再热能耗的空调热回收系统分析

Analysis of air conditioning heat recovery system for reducing reheat energy

为降低一次回风全空气空调系统空气处理机组再热能耗,提出两种改进空调热回收系统,分别是混风热回收系统和新回风热回收系统。基于空调系统空气处理流程的分析,结合热力学第一定律、空气处理机热质传递方程,建立了这两种空调热回收系统能耗的计算模型。在此基础上,以昆明地区为例,考察了空调室外新风参数、空调区域热湿比、新风量及送风量等主要因素对热回收系统能耗与效率的影响,并与常用回风热回收系统和一次回风系统进行了比较。研究结果表明,在温和地区采用新提出的两种热回收系统均比一次回风系统节能60%左右,消除了一次回风全空气系统存在的"冷热抵消"现象;新提出的两种热回收全空气系统能有效减少换热器初投资,缩短热回收设备投资回收期。

In order to reduce the reheat energy consumption in air handling unit of the primary return air system,two novel improved heat recovery systems(mixed air heat recovery system and fresh-return air heat recovery system)were proposed in this paper.Based on the analysis of the air handing process of air conditioning system,combined with the first law of thermodynamics and the heat mass transfer equation of air handling unit,the energy consumption calculation model of these two heat recovery systems was set up.Taking Kunming area as an example,the energy consumption and the energy saving rate change of the heat recovery system were studied by the effects of outdoor enthalpy,indoor heat and moisture ratio,fresh air volume and supply air volume.Compared with common return air heat recovery system and the primary return air system,the results showed that these two novel heat recovery systems in the temperate region can both reduce about 60%energy consumption than the primary return air system.These two novel heat recovery can eliminate the phenomenon of“hot and cold offset”in primary return air system.These two novel heat recovery systems can effectively reduce the initial investment of heat exchanger,and shorten the payback period of heat recovery investment.