室内湿度控制模式对夜间通风效果评价的影响

Influence of dehumidification control type on night ventilation evaluation

以某高校图书馆为例,分析了EnergyPlus软件的两种室内湿度控制模式对室内湿度和空调负荷预测及夜间通风节能效果评价的影响。结果表明,定湿度模式预测得到的室内湿度与设定值一致,定显热比模式预测得到的室内湿度波动较大,且室内人员密度越大或室内设计温度越低,预测结果偏离设定值越多。两模式算得的空调显热负荷相同,潜热负荷不同,且室内人员密度越大或室内设计温度越低,定湿度模式预测得到的潜热负荷和全热负荷超过定湿度模式的预测结果越多。若该建筑位于上海或西安地区,则典型日的夜间通风节能率均约为9%,且定显热比模式的预测结果稍大。采用定显热比模式计算空调负荷、评价夜间通风节能效果时需同时考虑日间室内湿度是否满足要求,尤其是对湿热地区室内人员密度较大或设计温度较低的建筑。如果室内湿度不满足要求,应采用定湿度模式。

The influence of dehumidification control type in EnergyPlus software on the predictions of indoor air humidity, air-conditioning load and energy efficiency of night ventilation in a university library was analyzed. The results show that indoor air humidity predicted by Humidistat model agrees well with the set point of air humidity, but air humidity predicted by Constant Sensible Heat Ratio model varies with time and is obviously different from the set point for the cases of high population density and low design temperature indoors. Air-conditioning sensible load calculated by the two models are equal, but latent load calculated by the two models are unequal. The latent load and total load of air conditioning system predicted by Humidistat model are obviously greater than those predicted by Constant Sensible Heat Ratio model for the cases of high population density and low design temperature indoors. The energy-saving rate of night ventilation is about 9% if the library is located on Shanghai or Xi’an. The energy-saving rate of night ventilation predicted by Constant Sensible Heat Ratio model is slightly greater than that predicted by Humidistat model. If Constant Sensible Heat Ratio model is adopted to predict air-conditioning load and to evaluate the energy efficiency of night ventilation,indoor air humidity at daytime should also be considered, especially for buildings with high population density and low temperature in humid and hot areas. If indoor air humidity is not satisfied, Humidistat model is recommended in EnergyPlus software.