Study on performance of energy textile installed in tunnel by CFD analysis and field tests

Textile-type ground-coupled heat exchangers, so called “energy textile”, were installed in an abandoned railroad tunnel, South Korea. In order to monitor the thermal behavior of the energy textile, a constant-temperature water bath (CWB) was adopted as a heat source for both cooling and heating operation. In the course of the experimental measurement, the inlet and outlet fluid temperatures of the energy textile, pumping rate, temperature distribution in the ground, and air temperature inside the tunnel were continuously recorded.Then CFD (Computational Fluid Dynamics) numerical analysiswas performed to simulate results from field measurements for the selected energy textiles with consideration of air temperature inside the tunnel. The convection coefficient method was applied in a developed numerical model with UDF (User Define Function) to consider effect of the air temperature inside the tunnel. Finally, the thermal performance of the energy textile is discussed with various types of ground-coupled heat exchangers.