Factors Analysis Of Ground Source Heat Pump System Suitability And Applicability

In the consumption of the energy structure in China, building energy consumption accounts for about 40% of total energy consumption of social. In the process of energy consumption, environmental pollution problems have received more and more attention. It has profound significantly that ground source heat pump(GSHP), which is a kind of clean, energy-saving, high efficient and renewable new energy technology, in the field of urban construction carries on the positive development, research and application. In recent years, the GSHP has entered the stage of popularization and application in large scale in china. But our country has a vast territory with large different climate from the Source to the North, if the GSHP application in different regions is improper, its advantages may be not fully played and even cause the initial investment waste.This paper uses TRNSYS software to simulate the GSHP operating conditions of an office building in Tianjin, validating the model through the comparison of measured value and simulated value. The paper also simulates GSHP of a typical office building in different climate zone in long-term operation and to analyze its application. In Harbin, which is as the representative of the cold area A, the average soil temperature of buried pipe area soil decreased gradually after GSHP running period of time, which reduced the operation efficiency in winter, it is not suitable for the use of the system alone. In Shenyang which is the representative of the cold area B and represented Beijing in cold area, it can be highly efficient and stable operation in the life time of the GSHP; In the hot summer and cold winter area represented by Nanjing and the hot summer and warm winter area represented by Guangzhou, the system running efficiency decreased obviously after GSHP running in a few years, which is not conducive to the GSHP continued effective operation.According to the analysis of the applicability of the results in different regions of GSHP, this article analyzes factors which affected the long term operation performance of GSHP from the aspects of heating, cooling in summer and winter time construction accumulated load ratio, depth of buried pipe, pipe spacing, soil thermal conductivity and the thermal conductivity of the backfill material. Founding that when the hourly building cooling load and the total accumulated heat load ratio is in between 0.4~1.5:1, the unit gets the balance of heat exchange from underground and the GSHP can be sustained and efficient operation. The rise of soil average temperature is decreased with the increase in depth of buried pipe and pipe spacing. In limited increase range of soil thermal conductivity, it has little influence on the soil average temperature. It is also found that thermal conductivity of backfill material thermal conductivity need be higher than drilling soil to ensure the heat exchanger has performance heat transfer, but not the higher the better.