Thermal Dynamic Analysis of Buried Hent Exchanger in Ground-source Heat Pump System in Cold Region
ZHENG Ping,WU Ming and ZHAO Ling
DOI:10.11835/j.issn.1674-4764.2011.03.018
Received December 18, 2010,Revised , Accepted , Available online July 01, 2015
Volume ,2011,Pages 100-106
- Abstract
In order to solve the frost-heaving safety problems of buried heat exchanger hydronic in ground-source heat pump, a mathematics mode1 and its contro1 equation were put forward according to heat transfer, filtration theory and mechanics of frozen soil, which is the couplings problem of temperature field, hydronic field and stress field. The temperature field, frost heaving displacement and stress distribution of ground-source heat pump in Daqing oilfield were simulated with finite elements method. The contrast and analyses are carried out according to the different soil depth, the different soil thermal conductivity in backfilled areas, the different spacing of tube foot. The results showed that the least temperature and heat affected zone in soil increases gradually with operating time. At the beginning of operation, the displacement of buried heat exchanger is small because the soil is not frozen. When the soil temperature reaches the phase temperature, soil volume increases in size, and then buried tube deforms. When soil temperature exceeds between -0.75℃ and -0.30℃, buried tube doesnt deform.