Heat transfer analysis model for medium-deep layer buried pipe heat exchanger

Abstract

The invention discloses a heat transfer analysis model based on a ground heat exchanger. The heat transfer analysis model comprises the following steps: S1, acquiring analysis parameters; s2, determining operation conditions according to the analysis parameters; and S3, heat transfer analysis is conducted on the middle-deep layer buried pipe heat exchanger based on the determined working conditions, specifically, under the heat taking working condition and the heat storage working condition, the heat transfer process outside the drilled hole of the middle-deep layer buried pipe heat exchanger is analyzed based on the heat front surface propagation rule, and heat transfer in the drilled hole is analyzed based on a one-dimensional quasi-steady-state heat transfer model. And coupling with the heat transfer process outside the drill hole through the temperature of the drill hole wall and the heat flow boundary condition. According to the model, various parameters adopted in actual engineering are used as input numbers based on an underground rock heat transfer rule, so that the problem of huge calculation scale or incapability of effectively implementing actual engineering problems caused by an overlarge pipe length-pipe diameter ratio of a middle-deep layer heat exchanger in a traditional grid division numerical method is solved; rapid analysis of the heat transfer process of the medium-deep layer buried heat exchanger with the ultra-large pipe length-pipe diameter ratio under any working conditions (including heat removal, heat storage and intermittent working conditions) is achieved.

Description

technical field

[0001] The invention belongs to the technical field of ground source heat pump and building energy saving, and particularly relates to a heat transfer analysis model of a middle-deep buried pipe heat exchanger. Background technique

[0002] Compared with the traditional shallow buried tube heat exchanger, the rock temperature change caused by the geothermal gradient and the non-uniform distribution of heat flux along the depth cannot be ignored for the heat transfer analysis of the middle and deep buried tube heat exchanger. Therefore analytical solutions based on simplified heat transfer analysis, such as the classical line heat source or column heat source models are no longer applicable. In addition, the medium-deep buried tube heat exchanger is characterized by a large tube length-to-tube diameter ratio as a typical structural feature, and the buried depth can reach 2~3km, resulting in its dynamic heat transfer process spanning multiple time and space sca...

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