地埋管间断工作进出孔平均温度预测方法研究

RESEARCH ON PREDICTION OF AVERAGE INLET AND OUTLET TEMPERATURE OF GROUND HEAT EXCHANGERS IN INTERMITTENT OPERATION CONDITION

按不改变每天总换热量的原则,将单位长度地埋管换热孔在制冷季或制热季中每天的实际释热或取热过程简化为一个矩形释热或取热脉冲,脉冲大小为单位长度地埋管换热孔的设计释热量或设计取热量,时间为每天的等效满负荷释热或取热小时数。采用线热源理论和热流叠加原理,推导若干个矩形脉冲负荷作用后地埋管换热器进出口温度平均值的计算公式,并通过长期现场岩土热响应试验对该公式进行了验证。在已知制冷季或制热季天数和地埋管换热器每天等效满负荷工作小时的基础上,通过设定地埋管在制冷季和制热季传热流体的最高或最低温度,可用该公式计算单位长度地埋管换热孔的设计释热量或取热量。

According to the principle of not change the total amount of daily heat exchange,simplify the actual heat release or heat extraction to a rectangular heat transfer pulse for unit length heat exchange borehole,the amplitude of the pulse is the design heat transfer capacity and the duration is the equivalent full load(i.e.design heat transfer capacity)working hours of unit length heat exchange borehole in a day.Based on the linear heat source theory and the superposition principle,several formulas for calculating the average temperature of heat-transfer fluid in ground heat exchanger are deduced on above simplifications,and one of the formulas is verified by long-term field thermal respose tests,which provide theoretical basis for the design of ground borehole heat exchanger,and also provides an effective method to decide heat transfer capacity for unit length borehole heat exchanger based on the conventional thermal response test.