The Optimization Of Operation Strategy Of District Energy Supply System During Cooling Season In Hot Summer And Cold Winter Zone

With the gradual consumption of traditional fossil energy, the growing tension of energy supply, and the growth of energy demand and the concern over air pollution, improving energy efficiency, making rational use of resources, saving energy and reducing emission have already been global concerned problems. Under this background, due to its great promising benefits in energy, environmental and operational aspects, high efficiency and energy conservation technologies such as district cooling and distributed energy system have attracted worldwide attention and application.Distributed energy system can realize district cooling, combining distributed energy system and district cooling can reduce the operational cost of district cooling and make district cooling hold an important position in the energy saving field. The high energy efficiency, economical and low environmental impact characteristics of district cooling and distributed energy system can be brought to full play only with reasonable configuration and operation. Therefore, it is essential to conduct optimization research on these two systems.This paper establishes a mixed-integer non-linear programming model of which the multistage objective function is maximizing cost saving ratio first and then maximizing energy saving ratio to optimize the operation of a district energy supply system, comprised of gas-fired distributed energy system and ground source heat pump during cooling season, and applies e QUEST software to simulate the annual hourly energy consumption of a typical public building community in hot summer and cold winter zone.Moreover, this paper optimizes the temperature difference between the chilled water supply and return of district cooling pipe network of this typical community from economic aspect. And the result of the analysis shows that the optimal temperature difference is 6.3°C. Furthermore, the influences of electricity price and natural gas price on the operation of this district energy supply system, and the result shows that when the electricity price is relative low and the gas price is relative high, gas-fired combined cooling, heating and power system does not operate, The regional loads are met by ground source heat pump and the grid; when the electricity price is relative high and the gas price is relative low, gas-fired combined cooling, heating and power system runs, The regional loads are met by gas-fired combined cooling, heating and power system first. If the energy is supplied not enough, ground source heat pump and the grid can provide the insufficient.Gas-fired distributed energy system integrated with ground source heat pump is the combination of natural gas and renewable energy sources, its effective operation can make up the shortcomings of each subsystem running individually and raising the energy saving and economical characteristics. Optimizing the configuration and operation of the Gas-fired distributed energy system integrated with ground source heat pump system can make the hybrid system more economical, environmental and energy-efficient and provide reference for the integration of distributed energy system and other renewable energy sources.