Numerical Investigation on the Performance of Horizontal Helical-Coil-Type Backfill Heat Exchangers with Different Configurations in Mine Stopes
Numerical Investigation on the Performance of Horizontal Helical-Coil-Type Backfill Heat Exchangers with Different Configurations in Mine Stopes
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DOI：
10.3390/math11194173
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发表时间：
2023-10
期刊：
影响因子：
2.4
通讯作者：
Bo Zhang;Long Shi;Wenxuan Zhang;Chao Huan;Yujiao Zhao;Jingyu Wang
中科院分区：
文献类型：
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作者：
Bo Zhang;Long Shi;Wenxuan Zhang;Chao Huan;Yujiao Zhao;Jingyu Wang
在充填矿井中应用地埋管换热器技术，可以实现地下蓄热，是解决太阳能不稳定、不稳定等问题的有效途径之一。利用COMSOL环境建立了某金属矿山采动层内5种结构的全尺寸水平回填式换热器的三维非稳态传热数值模型。为了保证对比分析的公正性，所研究的锅炉给水管具有相同的换热表面积。通过对连续运行3年的沸腾换热机组的储放热特性进行比较和评价，发现采用蛇形布置的螺旋管可以有效地提高沸腾换热机组的储放热性能。与传统的不锈钢沸腾换热式换热器相比，S-FH型的蓄热能力显著提高了21.7%，其次是SA-FH型，提高了11.1%，而U-DH型和SH型的性能则大大降低。此外，使用基于管内径的归一化参数C1和C2，进一步研究了关键结构因素（节距长度和节距直径）的影响。研究发现，BFHE应分布在C1较低的管道中，C2的增加有利于BFHE的储放热量的增加。通过对比分析导热系数的影响，发现导热系数对SH型、U-DH型、SA-FH型和S-FH型沸腾换热元件性能的积极影响依次减小。本文提出了一种优化管道布置的策略，以提高锅炉房的蓄热和放热潜力。
The application of ground heat exchanger technology in backfill mines can actualize subterranean heat storage, which is one of the most effective solutions for addressing solar energy faults such as intermittence and fluctuation. This paper provides a 3D unsteady heat transfer numerical model for full-size horizontal backfill heat exchangers (BFHEs) with five configurations in a mining layer of a metal mine by using a COMSOL environment. In order to ensure the fairness of the comparative analysis, the pipes of BFHEs studied have the same heat exchange surface area. By comparing and evaluating the heat storage/release characteristics of BFHEs in continuous operation for three years, it was discovered that the helical pipe with serpentine layout may effectively enhance the performance of BFHEs. Compared with the traditional SS BFHEs, the heat storage capacity of the S-FH type is significantly increased by 21.7%, followed by the SA-FH type, which is increased by 11.1%, while the performances of U-DH and SH type are considerably lowered. Also, the impact of the critical structural factors (pitch length and pitch diameter) was further studied using the normalized parameters C1 and C2 based on the inner diameter of the pipe. It is discovered that BFHEs should be distributed in a pipe with a lower C1, and increasing C2 encourages BFHEs to increase the storaged/released heat of BFHEs. By comparatively analysing the effect of thermal conductivity, it is found that the positive effects of thermal conductivity on the performance of SH, U-DH, SA-FH, and S-FH type BFHEs are found to decrease successively. This work proposes a strategy for improving the heat storage and release potential of BFHEs in terms of optimal pipe arrangement.