组合变风量空调系统研究

Combined variable air volume system

对中国8个典型气候条件下大型商场空调负荷及室外空气焓值的分析表明,在过渡期相当长的一段时期内,室外空气焓值低于室内时,因无法加大新风量,只好使用制冷机冷却空气.采用加大不经热湿处理的新风并与回风分别设计成独立的子系统而构成组合式变风量空调系统CVAV,并以人体舒适指标PPD为依据,计算了8种气候条件下系统所需的最大和最小风量.按回风系统为CAV或VAV,新风系统为VAV+CAV或VAV+VAV等组合计算得出,与现有定风量系统相比,在这8种气候条件下的节能量可达10%～36 6%.

The analysis of air-conditioning load and outdoor enthalpy of large department stores under eight typical climates in China indicated that in transition time, there existed a fairly long period, in which outdoor enthalpy was lower than indoor enthalpy, but water chillers were still used to cool supply air because outdoor air volume had reached its highest limit. It was suggested to largely increase outdoor air volume, not conditioned and designed as an independent subsystem. It combined with conditioned all air subsystem and constitutes a Combined Variable Air Volume System (CVAV). According to the human comfort index PPD, maximum and minimum air volume the system needs were calculated for 8 different climates. When conditioned air subsystem was designed as CAV or VAV and outdoor air as combination of VAV + CAV or VAV + VAV, calculation showed that energy saving could be as high as from 10% to 36.6% in comparison with conventional CAV system.