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Enhanced heat transfer performance of a new horizontal buried tube heat exchanger

To reduce the land area of horizontal buried tube heat exchanger, a finned strengthened heat exchanger was designed, and shallow geothermal utilization system model was established. The effects of fin shape and arrangement, soil type, ambient temperature and intermittent operation on the system's heat transfer performance were investigated. The soil utilization area of the heat exchanger is increased, and the heat exchange performance of the system is enhanced by adding fins on the smooth tube,. The optimal shape of the fins is rectangular, and the optimal fin layout is horizontal. When the soil property is clay, the heat transfer is the smallest, and the heat transfer performance is improved the most compared with the smooth tube. Intermittent operation not only improves the heat exchange, but also enhances the effect of adding fins to improve the heat exchange performance of the system. Compared with the original smooth tube, the soil utilization range is increased by 20 %, and the heat exchange is increased by 42%.
PAPER REVISED: 2022-07-22
PAPER ACCEPTED: 2022-07-27
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