Economic And Environmental Value Analysis Of Replacing Coal By Gas In Buildings

Replacing coal by gas is one of the important ways to solve air pollution and climate change,but has not been rapidly and widely implemented in China,mainly because there still exist a bit doubt about the economic and environmental value of replacing coal by gas.About 20% of China’s energy consumption comes from buildings,which is dominated by scattered coal.So promoting the replacement of coal by gas in buildings is important for China’s energy structure adjustment.Therefore,this paper is aim to point out the implementation direction and recommendations of China’s replacing coal by gas by analyzing the economic and environmental value of replacing coal by gas in different buildings.Based on the analysis of the status quo and problems of replacing coal by gas in China,the paper analyzes the cold,thermal and electricity energy flow in the separate production system and the cogeneration system,simulates the hourly cold,thermal and electricity load in a year of the six types of buildings in five climatic zones in China by the DeST software and hourly energy load sharing method,designs eight kinds of energy supply schemes included coal-based separate production system,gas-based separate production system,"electricity demand management" and "thermal demand management" modes of three different gas-based cogeneration system,uses the objective optimization method to calculate the economic and environmental value of replacing coal by gas in different buildings in different climatic zones,and finally conducts the sensitivity analysis of energy prices.The results show that,9 out of 30 buildings are economically viable to replace coal by gas;Replacing coal by gas should be prioritized in hotel buildings,office buildings and commercial buildings in cold zones,hot summer and cold winter zones,and hot summer and warm winter zones;The most economical and economical considering environmental externality options of replacing coal by gas are concentrated on the gas-based cogeneration system with the gas turbine and the micro-gas engine as the prime mover under the design mode of "electric constant heat" and gas-based separate production system.The study also believes that: considering the environmental external cost into the economic cost calculation of replacing coal by gas and adjusting the electricity price or gas price can all affect the choice of building uses’ energy consumption,thereby promoting the implementation of replacing coal by gas.