Design and operation of geothermal floor heating system in Tianjin, China

Abstract

Geothermal energy is increasingly used as a heat source for district heating systems in China. It is clean and has a lower operating cost. A geothermal floor heating system has an advantage over other heating systems because it lowers the discharge water temperature, so it can fully use the geothermal energy. Floor heating systems using geothermal energy have become very popular in Tianjin, China. This paper describes the geothermal resource and floor heating systems, specifically for buildings and conditions in Tianjin. Heat loss of a simple and typical building is calculated using Chinese codes. Using these values, the heat load of floor heating systems is determined. The paper also presents the design methods for pipe loops. Steady-state models are simulated for the different types of systems in China and Iceland, obtaining the operational parameters relative to outdoor temperatures. Applying these parameters, it is beneficial to optimize system controls in order to adjust the geothermal floor heating system effectively and conserve the geothermal resource, as also described in the paper.