辐射供冷和置换通风系统地板防结露数值模拟

Numerical simulation of floor condensation prevention in radiant floor cooling and displacement ventilation

地板结露现象是制约地板辐射供冷性能的最重要因素之一,研究地板表面除湿和抑制结露可以为实际工程的应用提供理论支持。文章数值模拟了地板辐射供冷与置换通风复合空调系统,研究了送风速度和湿度对预除湿持续时间的影响,利用垂直温差、吹风感和操作温度评价了人员舒适性,确定了因室内人员突增引起湿负荷变化需提前改变送风参数的时间范围。结果表明:送风湿度为6.5 g/kg、送风速度为0.1 m/s时,预除湿阶段可缩短到65 s;当送风湿度为8 g/kg、送风速度为0.05 m/s时,开启地板辐射供冷系统,在12 h工作时间内,垂直温差、吹风感和操作温度均满足夏季人员热舒适的要求;当室内人员分别突然增至2、4人时,散湿量由218 g/h分别变化到654和1090 g/h时,均可在10 min内降低送风湿度,从而避免由于湿度增加引起地板结露的现象。

Floor condensation is one of the most important factors restricting the performance of radiant floor cooling.The study of floor surface dehumidification and condensation suppression can provide theoretical support for the application of practical engineering.The numerical simulation of radiant floor cooling and displacement ventilation system was carried out by software,the influence of air supply speed and air supply humidity on the duration of pre-dehumidification was studied,vertical temperature difference,air blowing sensation and operating temperature were used to evaluate the personal comfort and then the time range of air supply parameters which need to be changed in advance due to the change of wet load caused by the sudden increase of indoor personnel was determined.The results show that the humidity of air supply was 6.5 g/kg,the air supply speed was 0.1 m/s,and the pre-dehumidification stage can be shortened to 65 seconds.When the humidity of air supply is 8 g/kg and the speed of air supply is 0.05 m/s,the floor radiant cooling system is opened,and the vertical temperature difference,air blowing sense and operating temperature all meet the requirements of thermal comfort of summer personnel within 12 hours of working time.When the indoor personnel suddenly increase by 2 and 4 people and the moisture dispersion changes from 218 g/h to 654 and 1090 g/h,respectively,the humidity of the supply air can be reduced within 10 minutes,so as to avoid the phenomenon of floor condensation caused by the increase of humidity.