水化热对地源热泵地埋管夏季换热效果的影响

Influence of Hydration Heat on Heat Transfer Effect of Ground Heat Exchanger of Ground Source Heat Pump in Summer

摘要:

通过数值模拟与现场实测地温的变化，研究了水泥水化热对地埋管周围地温的影响；通过理论分析、现场实测地埋管换热能力以及数值模拟研究了地埋管周围地温变化对地埋管夏季工况换热效果的影响。对上海自然博物馆地埋管系统的研究表明：（1）在地源热泵投入使用时，地下室底板以下约10m处的地温受水泥水化热影响最大，距离地下连续墙2.85m处地温的平均升高为2.2℃；（2）地埋管夏季工况的换热量随初始地温的升高而线性减小，地埋管周围地温每升高1℃，将使地埋管夏季工况的换热量减小5%以上。（3）地源热泵系统由夏季工况作为首次投入使用时应对距离地下连续墙13m以内地埋管采取相应措施，以保证换热系统高效运行。

Abstract:

Influence of the hydration heat by cement on the ground temperature around the ground heat exchanger was investigated by numerical simulation and field measurement for ground temperature. Influence of the ground temperature around the ground heat exchanger on the heat transfer effect in ground heat exchanger was investigated by theoretical analysis, heat transfer experiments of ground heat exchanger, and numerical simulation. Researches on the ground heat exchanger in Shanghai Museum of Natural History shows that the ground temperature approximately 10 m below the basement floor is most affected by the hydration heat of cement, and the average ground temperature 2.85 m away from the underground diaphragm wall increases by 2.2℃, when the ground source heat pump system is initiated. The heat transfer rate in ground heat exchanger decreases linearly with the increase in initial ground temperature in summer; Moreover, the heat transfer rate in the ground heat exchanger decreases by more than 5% in summer when the ground temperature around the ground heat exchanger is 1℃ higher. Measures should be taken to the ground heat exchangers whose distances between the underground diaphragm wall are no more than 13 m to ensure an efficiently operational heat transfer system, when the system is initiated in summer.