Radyant ısıtma sistemlerinin termal konfor performansının incelenmesi: Farklı ısıtma yüzey konfigürasyonlarının karşılaştırılması

This thesis is an experimental-numerical study for the thermal comfort assessment of radiant heating system for different heating configuration such as from a wall, ceiling and combination of both that is installed in a test room with dimensions of 4m x 4m x 3m. Comfort evaluation was done by using the PMV (The Predicted Mean Vote) - PPD (Predicted Percentage of Dissatisfaction) index developed by Fanger [1]. In addition, for each heating scenario, human body exergy balance was calculated and the effect of exergy consumption rate on thermal comfort was evaluated. The data generated during the tests are used in numerical model for the validation of it. Numerical model is used to investigate the air temperature distribution, velocity fields for different cases. Three different heating configurations were evaluated in numerical model as same as experimental study. Wall heating, ceiling heating wall and ceiling heating scenarios were explored in terms of PMV thermal comfort index and human body exergy balance approach. All the numerical analysis studies were conducted using the Academic version of ANSYS 17.1, which is a commercial package program for numerical modelling. It contains special modules for different stages of the modelling process. After the three-dimensional room geometry was created in the Design Modeler module, the meshing module was subjected to decomposition using the finite volume method. Numerical solutions were made in Fluent, a widely used computational fluid dynamics module. The temperature and velocity fields were visually inspected using CFD-Post software as the final processor program. The natural convection was modelled using the Boussinesq approach, and the standard k-ε model which is a common numerical solution was picked to model turbulence. A Discrete Ordinates model with no scattering was used for radiative heat transfer. Numerical solution results were compared with different mesh numbers and mesh independence was observed. Radiant panels have been investigated to provide and maintain thermal comfort at different surface set temperatures. In the given set values, temperature distribution in the vertical and horizontal direction, mean radiant temperature and air velocity values in the room were examined. It has been observed that the exergy consumption values in the radiant heating system are close to the lowest values stated in the literature. Also, the temperature distribution in the room is considerably lower than all conventional systems. This demonstrates that radiant systems using low quality energy sources provide efficient, environmentally-friendly comfort solutions. It should be stated that it is a preliminary study for the location-based heating technologies and this method can be an innovative solution for heating / cooling industry. Therefore, it can be further evaluated in future research studies.