Operation Strategy Analysis Of Chillers In Different Climate Zones

With the improvement of people’s living standards and the general urbanization,the demand for buildings in China is also increasing rapidly,and people’s demand for quality of life is also getting higher and higher.Therefore,the thermal comfort environment in buildings is getting more and more attention.In 2020,the scale of public buildings in China will reach 14 billion m~2,the annual power consumption will exceed 1 trillion k Wh,and the energy consumption will be about 346 million tce,of which the energy consumption of air-conditioning system will account for more than65%of the operating energy consumption of public buildings.Therefore,the analysis and research on the operation strategy of water chillers is a very potential direction in building energy conservation.In this paper the office building as the research object,and uses De ST software to simulate the annual dynamic building load of 8760 hours for five major climate zones in China:severe cold zone,moderate zone,hot summer and cold winter zone,cold zone,hot summer and warm winter zone.Through the load analysis of cooling season and heating season and the load analysis of typical days,the office building load characteristics of different climate zones are obtained.The office building load and outdoor dry bulb temperature were analyzed by linear regression.The load changes in different climate zones from large to small were 13.242k W in severe cold regions,3.143k W in hot summer and warm winter regions,3.131k W in hot summer and cold winter regions,3.061k W in cold regions,and 1.636k W in moderate regions when the temperature increased or decreased by 1℃.In order to achieve the goal of reducing energy consumption in building operation,office building loads in different climate zones are introduced into TRNSYS,and the numerical simulation of three chiller operation strategies,namely,average load distribution(strategy 1),sequential startup and shutdown(strategy 2),and average load after each startup(strategy 3),are carried out respectively.The average COP of chillers in the five climate zones is strategy 1>strategy 3>strategy 2.The total power of the air conditioning system in the five climate zones is the highest in Strategy 1,and slightly lower in Strategy 3 and Strategy 2.However,the power distribution of the two chillers in Strategy 3 is more balanced.The total energy consumption of severe cold area,cold area,hot summer and cold winter area,hot summer and warm winter area is the lowest under the operation of Strategy 3,which is 22.5%,20.9%,9.78%and 9.38%lower than Strategy 1 respectively;The moderate area has the lowest energy consumption under strategy 2,which can save 22.85%compared with strategy 1.Based on the carbon emission and economic analysis,the average load strategy of chillers after starting one by one is optimal in severe cold regions,cold regions,hot summer and cold winter regions,hot summer and warm winter regions,and the sequential starting strategy of chillers is optimal in moderate regions.