Study on Energy Storage Coupling System of Low-cost Geothermal Heating

With the increasingly serious environmental pollution, the utilization of clean resources such as geothermal energy is gradually increasing. Building heating is the main application mode of geothermal energy, but the existing geothermal energy heating system is mainly based on a single mode. Its heating mode is of the low-temperature difference and low efficiency. After the use of high-temperature water, that is directly discharged into the environment and the physical characteristics of high-temperature tailwater are seriously affecting the environment. At the same time, there are still problems of energy waste and high system operation. Therefore, to improve the utilization rate of geothermal energy, reduce the energy consumption of the system and reduce the operation cost is the key to promote the high efficiency and energy saving of the system. Based on the current situation of geothermal energy cascade utilization, this paper makes full use of the advantages of a TOU price of 1.0436 yuan/(kW ▪h) and 0.3923 yuan/(kW ▪h) in peak hour and valley hour in Tianjin, China. Taking 51000 square meters area of the office of Tianjin as the hypothetical scenario, a low-cost heating system with a coupled energy storage device is proposed. Using DEST software to calculate the hourly thermal load of buildings, and selecting the system operation cost as the economic evaluation index to compare with the conventional heating system, then analyzing the operation benefit of the system. The results show that the operation cost of the heating system in which coupled energy storage device is lower than the conventional system in general, and the operation cost of the coupling energy storage system is reduced by 21.8%, so the operation benefit is improved obviously.