Research on potential of development and utilization for shallow geothermal energy in Ordovician limestone of Jingxing County

Abstract:

In order to study the shallow geothermal energy contained in the Ordovician limestone of Jingxing County， a thermal response test well in the valley is drilled， where the physical mechanics， thermal properties and geothermal field characteristics of the rock and soil mass are tested. As a result， the average geothermal temperature below 10m reached 16.77℃， and the heat transfer per unit length in summer and winter under the test conditions were 68.38W/m and 65.78W/m， respectively. Eight indicators such as the burial depth of the groundwater level and the velocity of the groundwater were selected to evaluate the suitability of ground source heat pump with buried pipe in Jingxing County， and the evaluation area was divided into more suitable area， suitable area and unsuitable area. Among them， the more suitable area is 244.12km²， accounting for 16.82% of the total area. On this basis， the resource potential evaluation was carried out on the more suitable area， and the resource potential and energy saving and emission reduction capacity were calculated. In order to better verify the development and utilization value of the shallow geothermal energy contained in the Ordovician limestone of Jingxing County， the relevant supporting application engineering and monitoring equipment were installed to monitor the energy consumption under different test conditions. Compared with the energy consumption of the ordinary household air conditioners， the annual operating cost of ground-source heat pump with buried pipe is about 55% of the air conditioning， which possess the development and utilization value.

Key words:shallow geothermal energy;suitability evaluation;ground-source heat pump with buried pipe;Ordovician limestone;Jingxing County