In this research,the thermal performance of a single U-tube vertical ground heat exchanger is evaluated numerically as a function of the most influential flow parameters,namely,the soil porosity,volumetric heat capaci...In this research,the thermal performance of a single U-tube vertical ground heat exchanger is evaluated numerically as a function of the most influential flow parameters,namely,the soil porosity,volumetric heat capacity,and thermal conductivity of the backfill material,inlet volume flow rate,and inlet fluid temperature.The results are discussed in terms of the variations of the heat exchange rate,the effective thermal resistance,and the effectiveness of the ground heat exchanger.They show that the inlet volume flow rate,inlet fluid temperature,and backfill material thermal conductivity have significant effects on the thermal performance of the ground heat exchanger,such that by decreasing the inlet volume flow rate and increasing the backfill material thermal conductivity and inlet fluid temperature,the outlet fluid temperature decreases considerably.On the contrary,the soil porosity and backfill material volumetric heat capacity have negligible effects on the studied ground heat exchanger’s thermal performance.The lowest inlet fluid temperature reaches a the maximum effective thermal resistance of borehole and soil,and consequently the minimum heat transfer rate and effectiveness.Also,multilinear regression analyses are performed to determine the most feasible models able to predict the thermal properties of the single U-tube ground heat exchanger.展开更多
Aiming at the ground-coupled source heat pump that possesses the shortcomings of occupying larger land,this article studies the heat exchanged of heat exchanger in piling,and compares it with common heat exchangers bu...Aiming at the ground-coupled source heat pump that possesses the shortcomings of occupying larger land,this article studies the heat exchanged of heat exchanger in piling,and compares it with common heat exchangers buried directly. The result indicates that the heat exchanger makes the best use of structure of building,saves land,reduces the construction cost,and the heat exchanged is obviously more than exchangers buried directly. In winter condition,when W-shape pipe heat exchanger in pile foundation is 50 m deep and diameter is 800 mm,it transfers 1.2-1.3 times as large as the one of single U-shape buried directly at the flow rate of 0.6 m/s,whose borehole diameter is 300 mm. And in summer condition it does about 2.0-2.3 times as that of U-shape one.展开更多
埋地换热器换热性能是地源热泵设计基础,针对不同埋管方式埋地换热器建立了砂石回填单 U 型、双 U 型井埋管和混凝土回填单 U 型井埋管的单井实验系统,开展埋地换热器单井的换热性能实验研究。研究了不同的土壤物性、回填材料、埋管数...埋地换热器换热性能是地源热泵设计基础,针对不同埋管方式埋地换热器建立了砂石回填单 U 型、双 U 型井埋管和混凝土回填单 U 型井埋管的单井实验系统,开展埋地换热器单井的换热性能实验研究。研究了不同的土壤物性、回填材料、埋管数量和运行工况下单井换热器换热性能。展开更多
为了研究分析单井循环地源热泵系统的换热性能情况,利用数据采集监测系统,对绵阳市某单井循环地源热泵系统进行换热性能测试研究。由数据采集监测系统进行数据采集,最终计算出单井循环系统的实际换热量,测试结果表明该地源热泵系统换热...为了研究分析单井循环地源热泵系统的换热性能情况,利用数据采集监测系统,对绵阳市某单井循环地源热泵系统进行换热性能测试研究。由数据采集监测系统进行数据采集,最终计算出单井循环系统的实际换热量,测试结果表明该地源热泵系统换热量平均只有25 k W,没有达到初期的设计要求。分析该系统存在的问题,提出优化方案及建议。展开更多
文摘In this research,the thermal performance of a single U-tube vertical ground heat exchanger is evaluated numerically as a function of the most influential flow parameters,namely,the soil porosity,volumetric heat capacity,and thermal conductivity of the backfill material,inlet volume flow rate,and inlet fluid temperature.The results are discussed in terms of the variations of the heat exchange rate,the effective thermal resistance,and the effectiveness of the ground heat exchanger.They show that the inlet volume flow rate,inlet fluid temperature,and backfill material thermal conductivity have significant effects on the thermal performance of the ground heat exchanger,such that by decreasing the inlet volume flow rate and increasing the backfill material thermal conductivity and inlet fluid temperature,the outlet fluid temperature decreases considerably.On the contrary,the soil porosity and backfill material volumetric heat capacity have negligible effects on the studied ground heat exchanger’s thermal performance.The lowest inlet fluid temperature reaches a the maximum effective thermal resistance of borehole and soil,and consequently the minimum heat transfer rate and effectiveness.Also,multilinear regression analyses are performed to determine the most feasible models able to predict the thermal properties of the single U-tube ground heat exchanger.
基金Project(2006BAJ03A10) supported by the National Key Technology R&D Program of China
文摘Aiming at the ground-coupled source heat pump that possesses the shortcomings of occupying larger land,this article studies the heat exchanged of heat exchanger in piling,and compares it with common heat exchangers buried directly. The result indicates that the heat exchanger makes the best use of structure of building,saves land,reduces the construction cost,and the heat exchanged is obviously more than exchangers buried directly. In winter condition,when W-shape pipe heat exchanger in pile foundation is 50 m deep and diameter is 800 mm,it transfers 1.2-1.3 times as large as the one of single U-shape buried directly at the flow rate of 0.6 m/s,whose borehole diameter is 300 mm. And in summer condition it does about 2.0-2.3 times as that of U-shape one.
文摘为了研究分析单井循环地源热泵系统的换热性能情况,利用数据采集监测系统,对绵阳市某单井循环地源热泵系统进行换热性能测试研究。由数据采集监测系统进行数据采集,最终计算出单井循环系统的实际换热量,测试结果表明该地源热泵系统换热量平均只有25 k W,没有达到初期的设计要求。分析该系统存在的问题,提出优化方案及建议。
