关键词: 地采暖地板, 蓄热, FVM, FLUENT, 温度分布

Abstract: [Objective] In order to detect the thermal storage capacity of wood materials used for floor heating, a method based on an airtight and thermal-insulated testing device is firstly proposed.[Method] Firstly, the structure of airtight and thermal-insulated testing device was illustrated, and the testing method was introduced. Then, the physical model of testing device was built up, the mass conservation equation, momentum equation and energy conservation equation of three-dimensional unsteady heat transfer were established according to the three laws of fluid mechanics. The preheated wood samples from Betula platyphylla, Fraxinus mandshurica, Betula alnoides and Quercus mongolica, which could be used for floor heating, were set at the middle of the bottom of the testing device, as heat source. After setting up the initial values and boundary conditions of the model, the CFD software FLUENT was used with certain numerical simulation parameters to solve the unsteady heat transfer equations established before, and the temperature distributions in the testing device at different periods were analyzed and discussed. Furthermore, taking the 1 000 step result as an example, the temperature distribution result from the numerical model and the measured temperature data of the testing device were compared and evaluated based on the average relative error and correlation coefficient. And by doing these, the consistency of the established heat transfer model and the testing device was evaluated.[Result] The relative error is lower than 1.5%, and the correlation coefficient is higher than 0.98. In addition, the simulated time to reach temperature equilibrium of all different samples are less than the measured values, and the simulated equilibrium temperature distributions of different sample are lower than the measured values.[Conclusion] The model and testing device we developed can accurately demonstrate the temperature distribution and variation of different wood samples, and thus it can be used to evaluate the heat storage performance of different wood floor materials used for floor heating system.

Key words: wood floor for floor heating system, heat storage, FVM, FLUENT, temperature distributions