温室地下蓄热系统换热特性研究

针对现行温室地下埋管式换热系统结构的缺点,为充分利用地下蓄热,提高地温和夜间环境温度,设计了一种新型温室地下蓄热系统。测定了系统蓄热与放热时进出口空气温度、湿度与换热管道出口处空气的流速。试验结果表明,温室地下蓄热系统蓄热和放热时进口空气与出口空气的温度差、焓差较大,其差值随系统运行时间降低,白天蓄热量与夜间释放热量大于系统消耗的电能,蓄热时运行时间不宜大于4.5 h。

Heat exchanging characteristics of underground heat storage system in greenhouses

A new underground heat storage system for greenhouses which overcomes the structural drawbacks of the heat exchanging system with buried pipes was designed in order to make full use of underground saving heat and increase soil temperature and environmental temperature at night. Some parameters, including air temperature, air humidity at the inlet and outlet, and air flow velocity of flow at the outlet of heat exchanging pipes, were measured during heat saving and heat releasing in this experiment. The results indicated that air temperature and enthalpy at the inlet are distinctly different from that of outlet during heat saving and heat releasing and the differences reduce with the running time. Both the heat saved in the daytime and the heat released at night are greater than the electric energy consumption of the system, and the proper heat saving time is not more than 4.5 h.