The Heat Analysis And Improving Measures Of A Over-long Gravity Heat Pipe’s Extracting Geothermal Technology

Related to use of geothermal energy heating technology is extracting underground hot water directly,which cause some issues land subsidence,underground hot water to recharge and secondary pollution.Over-long gravity heat pipe extract the deep geothermal technology has the characteristics of safe and reliable,groundwater protection,no pollution can avoid to produce problems,but the technology mostly in the form of patents, the basic theory to be in-depth study.In this paper, the over-long gravity heat pipe through theoretical analysis and extraction of deep geothermal technology application,effective use of this technology to provide a certain basis in the future.According to the technology patent built a heat pipe test by a energy company,the author aimed at the heat pipe test theory and experimental data analysis,find out the influence factors of the gravity heat pipe heat wells of transfer performance,then mainly through to the heat pipe wells structure improvements,improve the heat transfer performance.Finally,the heat pipe test wells make a further idea structure and the working medium.In this paper,combined with the conventional gravity heat pipe experiment experience and theoretical analysis,the heat pipe test wells is not affected by the conventional heat transfer limit,calculate the charging rate is 10%,when is suitable for heat pipe in site test wells;Through the analysis on liquid pool in evaporation part of the average heat transfer coefficient decreases with increasing diameter,the diameter is too big,the heat pipe test wells restricts its heat transfer performance.In the second,the flow resistance is calculated only 561.7Pa.It is concluded that the steam flow can flow to the ground top,but due to gravity heat pipe heat transfer in the test in the early period of no heat preservation measures,led to the steam is condensed into the heat exchanger has been all along the way.To improve the test three times:the first improvement experiment by setting the shunt pipe and additional wire core on both ends of the pipe section,observed that a small amount of water.The second improved test by settingthe casing,the measured and calculated pool side maximum capacity is 174 k W;Third to improve experiment by setting the casing,the measured and calculated the pool side maximum capacity is 190 k W.Finally,from the inside pipe wall surface and heat transfer process,absorption structure,choice of working medium for heat pipe test wells,further the application of this technology for the future.