This project belongs to the field of energy and environmental technology.
With the requirements of sustainable development and the construction of a conservation-oriented society, giving priority to the use of renewable energy and rational use of resources have become the basic principles of energy utilization. Ground source heat pump is a heat pump technology that utilizes low-grade renewable energy. However, due to the lack of maturity of relevant domestic technologies, problems such as the adaptability of shallow geothermal energy utilization have arisen in practical promotion and application. It is reflected in: problems such as imperfect early design links, unbalanced heat and cold, and unsatisfactory comprehensive energy efficiency, which make the energy-saving benefits of ground-source heat pump systems not obvious; surface water heat pumps are used less, design basis and system integration technology are lacking, and construction technology is imperfect. etc. problem. In addition, the heat pump also has problems such as a sharp drop in efficiency when the outlet water temperature is too high.
In view of the lack of basis for application design of domestic ground source heat pump projects, the urgent need to supplement basic work, and the backward heat pump technology and equipment, under the National Natural Science Foundation of China and its international cooperation projects, the Doctoral Program Fund for Colleges and Universities, the Shanghai City and Technology Commission's major technological research projects, and the Shanghai City Science and Technology Commission Expo Science and Technology Special Fund, theoretical and key technology research on ground source heat pump application environment survey, equipment research and development, engineering design and system evaluation have been systematically carried out: ① Through theoretical analysis and experimental research, new working fluids for ground source heat pumps were explored, and programs for physical property analysis and critical heat pump thermodynamic calculation were developed. For the first time, a critical heat pump with HFC125 working fluid that can be used for "one machine" was proposed, and the performance characteristics of HFC125 and HFC125/HCs mixed working fluid heat pump systems were analyzed;② Optimize the original oversimplified soil thermophysical model and calculation method, and develop a new convenient, stable and high-precision soil thermophysical property tester; ③ Aiming at the problems existing in the discrete numerical calculation model and combining the advantages of the finite long-line heat source model, a numerical line-source comprehensive model for underground pipes of ground source heat pumps is proposed to simulate the thermal response of underground pipes of ground source heat pumps more quickly and accurately; ④ By studying the heat transfer laws of stagnant surface water bodies, and coupling indoor load and outdoor meteorological parameters, a three-dimensional dynamic water temperature model of surface water source heat pump was established, and the maximum carrying load index limits for water bodies at different depths in Shanghai were proposed; 5 Three-dimensional models of different heat exchange coil types were established, a dynamic method for economic evaluation of ground source heat pumps was proposed, and a ground source heat pump system design software was developed by coordinating the surface water body model, coil heat exchange model and water body carrying capacity model.
The project results took 15 years to be completed and formed key technologies with independent intellectual property rights: 2 invention patents were obtained, 34 papers were publicly published, and 12 doctoral and master's students were trained. The key technological breakthroughs and integrated innovations achieved by this project have not only been applied to large-scale public buildings with important influence, such as the Shanghai World Expo Cultural Center, the Expo Axis, the Dianshan Lake Oriental Green Boat Demonstration Project, etc., but also applied to ultra-large residential projects. Community projects, such as the 220,000 m2 Chinese enterprise Yude Jiangyin Residence, Landsea Green Street and other representative projects, provide key technical support and demonstration for the application of ground source heat pumps in Shanghai and even the country, and scientifically guide the application of engineering. The application of the project has achieved great social influence. For example, Xinhuanet conducted a special report on buildings such as the Expo Axis and the Cultural Center, saying that they are "praised as buildings that lead the technological trend and are full of 'wisdom' in China's construction industry." According to incomplete statistics, the construction area applied by the project exceeds 1.22 million square meters, creating an output value of 508 million yuan, directly saving more than 5142 tce of standard coal every year, and reducing carbon dioxide emissions by more than 12858 tons.