Stochastic Heat Transfer Analysis on Buried Pipe of Ground Source Heat Pump with Monte-Carlo Method
|School||Wuhan University of Technology|
|Keywords||buried pipe Monte-Carlo method stochastic finite element sensitivity|
With the development of society and gradually forward of the urbanization process, there is more and more building energy consumption. However, due to the energy shortage, energy conservation and emission reduction in buildings has become the focus of attention. Because of the energy conservation and environmental protection, the technology of ground source heat pump(GSHP) has been rapidly applicated and promote in building.In this paper, after reading a large number of the papers about ground source heat pump, many random factors has been found in heat transfer process of ground source heat pump. In order to reflect the randomicity of these parameters and research the heat transfer characteristics of buried pipe more accurately, a stochastic model was applied for heat transfer of buried pipe, some stochastic parameters (such as inlet temperature, soil temperature, soil density, etc) were chosen and assumed that its satisfy uniform distributions. The outlet temperature, the quantity of heat exchange and theirs sensitivity with these parameters were analyzed with Monte-Carlo stochastic finite element method. The main work are as follows:Established the mathematical model of buried pipe. The model was divided into two parts. One part was fluid flowing model in U-tube, the other was the soil heat transfer model of pipe radius around the temperature distribution;Analyzed the statistical characteristic of random factors in the heat transfer process of ground source heat pump, such as thermal properties of soil, soil temperature, inlet temperature, velocity of fluid, depth and effective radius of U-tube, et al;Simulated the operating conditions of buried pipe of ground source heat pump in summer, established the fluid—solid coupling model by FLOTRAN CFD and obtained the distribution of temperature field. Then, It was established the stochastic model by Latin Hypercube Sampling method, used probability method to analysis the outlet temperature and quantity of heat exchange which reflect characteristics of heat transfer, and analyzed the sensitivity of their with the each random parameters;Analyzed the change rule of outlet temperature and quantity of heat exchange with inlet temperature, soil temperature, internal velocity, thermal properties of soil, depth and effective radius of U-tube and the other parameters which influence the performance of heat exchanger. Analyzed the reasons for the change rule, consider both the outlet temperature and quantity of heat exchange, were given the parameters of the optimal design advice.