Method for improving heat exchange performance and longitudinal local heat accumulation of buried pipes of ground-source heat pump

Abstract

The invention provides a method for improving heat exchange performance and longitudinal local heat accumulation of buried pipes of a ground-source heat pump. Heat conductivity of a plastic pipe can be improved by winding a common plastic pipe with metal wire that is low in cost and high in heat conductivity coefficient. By analyzing the thermophysical parameter of soil in a pipe burying zone, thesoil in the pipe burying zone is reasonably layered, and analytic models for the soil layers are established on ANSYS software; optimum equivalent heat conductivity coefficient of the composite plastic pipe in each layer of the soil model then is determined, and the required length of the metal wire, the distance between metal wires, and the winding number of the metal wires on the buried pipes in each layer of the soil model are then calculated; and according to the calculated distance between metal wires, the plastic pipe is winded with the metal wires to obtain the composite buried pipe having optimum heat conductivity. The method can simply and effectively improve the heat exchange performance of the buried pipes and also can solve the problem of local heat accumulation since the thermophysical parameters of soil in the layers are different due to soil layering. The method is low in manufacturing cost, has extensive application range and can be extensively promoted.

Description

technical field [0001] The invention relates to the field of ground source heat pumps, in particular to a method for improving the heat transfer performance and longitudinal local heat accumulation of buried pipes of the ground source heat pump. Background technique [0002] Ground source heat pump is an efficient, energy-saving and environmentally friendly air-conditioning system that uses underground shallow geothermal resources to provide both heating and cooling. However, due to the high initial investment of the ground source heat pump system, the utilization rate of the ground source heat pump is low. , There are many reasons that restrict and affect the promotion and development of ground source heat pump technology, among which the poor heat transfer performance of buried pipes is the main reason that affects the entire system. The heat transfer performance of the buried tube heat exchanger is affected by many factors, mainly including the thermophysical properties o...

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Problems solved by technology

In fact, due to different soil depths, different soil structures and types, the thermophysical properties of the soil in the longitudinal direction have certain differences. The difference is very far, and even lead to partial failure of the buried pipe heat exchanger

[0004] At present, plastic pipes are often used for buried pipes. The advantages of this type of pipe are low price, easy access, and strong corrosion resistance. However, due to their small thermal conductivity, the heat transfer efficiency of buried pipes is limited to a certain extent. The whole ground source heat pump system does not work well

In view of the existing problems of ground source heat pump pipes, the commonly used method is to mix a certain proportion of materials with better thermal conductivity in the manufacture of the plastic pipes. The cost of such composite pipes is relatively high, which is not conducive to the promotion of ground source heat pumps. use

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