摘要
并联双U形换热器具有不同温度的两种或两种以上介质之间传递热量,尤其在流固热量交换过程受介质温度以及饱和度等因素的影响,换热器的换热特征和热阻计算难度较大。为此,提出一种基于热力计算的并联双U形换热器数值模拟方法。用积分思想将管内流体拆为微元容积,根据能量守恒定律,对各微元段体积建立微元方程。计算孔隙度、饱和度、渗透性以及过余温度场,采用热力计算方法土壤温度,获取土壤的吸附力与土壤饱和性,实现并联双U形换热器数值模拟。通过数值模拟回填材料导热系数、钻孔深度以及钻孔直径对换热器热阻的影响,基于此,设计仿真验证研究方法的有效性,结果表明,所提出的模拟方法能够准确模拟不同流速下换热器的换热特征、不同桩基长度下换热器排热情况,为换热器运行的稳定控制提供了可靠支持。
The parallel double U-shaped heat exchanger has the heat transfer between two or more media with different temperatures.Especially in the process of fluid solid heat exchange,it is difficult to calculate the heat transfer characteristics and thermal resistance of the heat exchanger due to the influence of media temperature and sat-uration.Therefore,a numerical simulation method of parallel double U-shaped heat exchanger based on thermody-namic calculation was proposed.Firstly,we used the idea of integration to divide the fluid in pipe into infinitesimal volume.According to the law of energy conservation,we created the infinitesimal equation for the volume of each in-finitesimal section and then calculated the porosity,saturation,permeability and excess temperature field.Meanwhile,we used the thermal algorithm to calculate the soil temperature,and obtain the adsorption force and saturation of soil,thus realizing the numerical simulation of the parallel double U-shaped heat exchanger.Finally,the influences of the thermal conductivity of backfill material,the drilling depth and the drilling diameter on the thermal resistance of heat exchanger were simulated.On this basis,a simulation was designed to verify the effectiveness of the proposed method.Simulation results show that the proposed method can accurately simulate the characteristics of heat exchanger under different flow rates and the heat extraction of heat exchanger under different pile length,which provides reliable sup-port for the stable control of heat exchanger.
作者
刘莉莎
王伟
房昕
LIU Li-sha;WANG Wei;FANG Xin(School of Prospecting&Surveying Engineering,Changchun Institute of Technology,Changchun Jilin 130021,China;School of Civil Engineering,Changchun Institute of Technology,Changchun Jilin 130026,China;College of Civil Engineering,Jilin Jianzhu University,Changchun Jilin 130118,China)
出处
《计算机仿真》
北大核心
2023年第6期388-392,共5页
Computer Simulation
基金
吉林省教育厅“十三五”科学技术项目(JJKH20200626KJ)。
关键词
热力计算
换热器
流量
孔隙度
Thermodynamic calculation
Parallel double U-shaped heat exchanger
Flow rate
Porosity
