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

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.