地源热泵系统逆向建模度日数G函数法

Degree-day G-functions approach of inverse model for ground source heat pump

提出了1种地源热泵系统逆向建模方法———度日数G函数法,利用地埋管换热器的温度响应与负荷的线性叠加关系,结合度日数法估算负荷,采用约束非线性单纯形法拟合模型参数.分别应用数值试验和2年的现场实测,通过与传统的管道蓄热系统(DST)模型调试法对比,对新模型进行了验证.与基于实测负荷的DST调试法相比,基于气温的度日数G函数法拟合误差的标准差约大30%,主要是由度日法预测负荷的误差引起.但当拟合计算中地埋管换热器参数的估值与实际值差距较大时,DST调试法的误差大于度日数G函数法.度日数G函数法只需要最少量的实测参数,适用于对住宅建筑的地源热泵空调系统的逆向分析.

An inverse model for ground source heat pump（GSHP）,degree-day G-functions approach was proposed.The model was based on superposition theorem of geothermal heat exchangers（GHE） and degree-day model for estimating load,while model parameters were fitting by a simplex method.A residential vertical GSHP was monitored for two years.The simulated data and the monitored data were performed to validate the results from the degree-day G-functions approach and traditional duct storage systems（DST） calibrated approaches as comparison.The standard deviation of the predicted data of the degree-day G-functions approach was higher 30% than that of the DST calibrated approaches,mainly because of the predicted error of the GHE load by the degree-day model.When an inaccurate estimation of GHE parameter was used in the DST calibrated approaches,the error of the DST calibrated approaches was higher than that of the degree-day G-functions approach.It is shown that the degree-day G-functions approach is appropriate for the quantitative inverse modeling for residential GSHP.