Study Of Shallow Ground Source Heat Pump For North Of China

The system of Ground-source heat pump is a sort of high effect and economy new technology, and it is able to realize sustainable development. It is deemed to be one of the heat pump air condition technology of this century, which possess most develop future. However, the application of shallow undersurface ground source heat pump faces many problems, such as the lower technology level, the not good region adaptability, the lag of theory study, the difficulty of maintenance and so on. Moreover, the key technology thereinto that the calculate theory of soil burying pipe heat exchanger is juvenility. Its abroad application falls under restrict. Therefore, the series of Ground-source heat pump productions that suit the characteristic of our country and satisfy vary requires still not form, and it awaits exploitation actively. The task of this paper is working out a sort of shallow undersurface ground source heat exchanger, which makes the best of shallow undersurface ground source and has strong adaptability, and promoting the abroad expand of Ground-source heat pump in the south of our country.The design idea of a new-style ground-source heat exchanger is introduced. This kind of heat exchanger consists of two buffers or boxes which can make static pressure and liquid distribution homogeneous and the heat-exchange pipes between them.After being distributed, the flow in all heat-exchange pipes has the same direction, so the heat loses among the pipes are eliminated. Therefore, the heat exchanger can make good use of shallow undersurface ground source. Besides, its structure is simple and feasible and it is easy to be laid and maintained. It is especially fit for country and towns. Based on the basic heat transfer theories and energy balance equations, heat convection and conduction theories, develops a concise arithmetic model for the design of buried heat exchangers. This model presents the related equation between the length of the heat exchange pipe and the liquid temperature at the inlet and the outlet of the pipe.Take the heat exchanger of shallow undersurface soil source heat pump as research object, the corresponding experiment stage has been established in Hunan university campus. We confirmed the burying deepness of shallow undersurface ground-source heat exchanger with two meters viaing testing and analysing soil parameter of burying pipe location. By experiment in summer and winter, we find this kind of heat exchanger is better than upright burying pipe in exchange quantity of heat in unit length, and the exchange quantity of heat can achieve to be double of common plane burying pipe. This kind of heat exchanger can make full use of shallow undersurface ground-source. The result of comparing matrix count value and fact test value indicates the fact, that the count value and fact test value of water temperature at the outlet of heat exchanger can be well inosculated in summer, and the error within 2%. At the same time, we have analysed the change and resume instance of initialize temperature field of soil.