Monitoring And Simulation Of Operating Characteristics For A Ground Source Heat Pump System In Chongqing

Ground Source Heat Pump(GSHP) technology, a kind of energy conservation and environmental protection technology, has been widely applied in the practical engineering, but is greatly influenced by environmental factors in actual use. Chongqing belongs to the hot summer and cold winter region, which has some constrictions for the application of GSHP technology, so this thesis mainly studies of GSHP technology in Chongqing area, and does the research of operating characteristics and plan optimization for GSHP system based on a building in Chongqing through the way of measurement and simulation.Firstly, the data of energy consumption monitoring system for two summer and one winter and the data of ground temperature monitoring system for three years are respectively processed, and the variation of the parameters are analyzed, including the water temperature of inlet and outlet of the unit, energy consumption, COP of the heat pump unit and system, energy efficiency ratio of cooling water system, energy-saving rate and the temperature of the ground. It is concluded that GSHP system is affected by environmental factors such as air temperature, soil temperature and so on, and in the summer the operation effect of the system is good, and buried tube heat exchange capacity is stable, but in the winter the operation effect of the system is bad due to with low load rate and high outlet temperature of source side.Secondly, based on the actual office buildings, the building energy consumption model is established with DeST to simulate the hourly load changes of the construction. GSHP system model is established with TRNSYS, which is verified by comparison between the measured value of outlet temperature of source side and ground temperature and their corresponding simulation value. After 20 years of long-term simulation prediction, system efficiency is reduced from 3.12 to 2.72, and ground temperature is risen from 20? to 30.5?. the problem of heat accumulation under the ground during long-term performance is found.Finally, two measures for relieving soil heat accumulation are respectively taken from the perspective of increasing soil heat dissipating capacity and reducing soil heat gain capacity, which are operating hot water system and cooling tower auxiliary cooling system. The models are also respectively established to analyze system and compare the control strategy with each other, and the more efficient solution is found in the end. The optimal control strategy for hot water system is that the hot water system operates in the 3rd year, and hot water unit operates in the case that the inlet temperature of water tank from hot side is below 45?, while closed in the case that the outlet temperature of water tank from hot side is higher than 55?. The optimal control strategy for cooling tower auxiliary cooling system is that cooling tower operates in the 3rd year, which supplemental cooling rate is 50%, and the cooling tower operates when temperature difference between the inlet water temperature of the cooling tower and the environment wet bulb temperature is higher than 4?, and vice shuts down. The system with two kinds of control strategies is more efficient.This thesis mainly does the research of operating characteristics and simulation for GSHP system in Chongqing. On the one hand, the operating characteristics for a GSHP system can be analyzed with long-term monitoring data in practical engineering, which provides reference for the design and operation of GSHP in Chongqing area, and is rich in research for GSHP system in hot summer and cold winter region. On the other hand, the problem of soil heat accumulation in the practical engineering can be better solved through the simulation to GSHP system so that the energy consumption of system also can be reduced.