基于正交试验的地道风系统换热性能优化研究

Optimization of heat transfer performance of earth-air heattransfer system based on orthogonal test

为了提高地道风系统的换热性能,建立了地道风系统换热理论模型并进行了验证。采用正交试验方法,以换热效率、换热量和性能系数为评价指标,研究了通风时间、空气流速、地道当量直径、地道长度、土壤类型和地道埋深对地道风系统换热性能的影响。结果表明:地道当量直径对不同指标均有显著影响,是影响换热性能的最关键因素;试验条件下系统换热性能的最优水平组合为空气流速3 m/s、地道当量直径0.3 m、地道长度90 m、土壤类型砂岩,该组合下系统换热效率为70%,换热量为2 550 W,性能系数为8.94。

In order to improve the heat transfer performance of the earth-air heat transfer system,a theoretical model of heat transfer of the earth-air heat transfer system is established and validated.Using the orthogonal test method,taking heat transfer efficiency,heat transfer quantity and coefficient of performance as evaluation indexes,the effects of ventilation time,air velocity,tunnel equivalent diameter,tunnel length,soil type and tunnel buried depth on the heat transfer performance of the earth-air heat transfer system are studied.The results show that the tunnel equivalent diameter has significant influence on different indexes and is the most key factor affecting the heat transfer performance.The optimal level combination of heat transfer performance of the system under the test conditions is air velocity 3 m/s,tunnel equivalent diameter 0.3 m,tunnel length 90 m,and soil type of sandstone.Under this combination,the heat transfer efficiency of the system is 70%,the heat transfer quantity is 2550 W,and the coefficient of performance is 8.94.