地埋管换热器G函数插值法及应用

APPLICATION OF G-FUNCTIONS INTERPOLATION APPROACH FOR GEOTHERMAL HEAT EXCHANGERS

利用地埋管换热器线性叠加传热特征,提出一种地埋管换热器的逆向建模方法——G函数插值法。采用约束非线性单纯形法求解反卷积计算,拟合模型参数。G函数插值法不涉及具体的地埋管换热器结构,无需换热器的内部参数,适用于多种地埋管换热器。根据某地源热泵空调系统的实测记录数据,应用G函数插值法和传统的DST调试法分别进行地埋管换热器的逆向建模及预测。结果表明:在实例中两种方法拟合预测结果较好,G函数插值法拟合误差和预测误差均小于DST调试法,日记录数据误差是产生逆向建模拟合预测误差的主要原因。

An inverse model for geothermal heat exchangers （GHE） in ground source heat pump, G-functions interpolation approach was proposed based on superposition theorem of GHE, while model parameters were fitting by a simplex method. Being not related to special GHE structure, G-functions interpolation approach does not require any parameters of GHE and can be used for various type of GHE. A vertical ground source heat pump system had been monitored and recorded for two years. The monitored data were performed to validate the results from the G-functions interpolation approach. A detailed duet storage system （DST） model of a GHE was calibrated to monitored data. The results show the appropriateness of the G-functions interpolation approach and the DST calibrated approach for the quantitative modeling of GHE. The error of GHE water temperature calculated by the G-functions interpolation approach is less than the DST calibrated approaches. The errors of daily recording data are the main cause of the error of predicted data.