The Energy-saving Transformation And Energy Consumption Analysis Of A Central Air-conditioning System

Building energy consumption has become one of the three "major energy consumers" in our country's energy consumption. Currently , building energy consumption accounts for about 30% of the total social energy consumption. There are the existing buildings of nearly 400 million square meters,of which 99% are high-energy consumption buildings,and more than 95% of the new buildings are in the same column as well. The areas of state organs of office buildings and large public constructions accounts for the town total construction area less than 4%,but the power consumption quantity is 22% of the total of urban consumption each year, and the power consumption per unit area is as high as 10 to 20 times of ordinary residential level. On the other hand, building energy consumption accounts for about 27.4% of total energy consumption in our society, while the air conditioning and heating energy consumption of buildings can always be about 50% to 70% of total energy consumption. Large public buildings have become increasingly prominent high-energy consumption, energy-saving type of construction work as the focus of the current building energy efficiency. As the prominent problems of high energy consumption of the large-scale public buildings,for this kind of buildings, the energy saving renovation work becomes the focus of the current building energy efficiency.In this paper,the main teaching building of Chongqing University was taken as the research object,first of all,According to the problem of "big flow, small temperature difference" appeared in the process of operation, the original air conditioning system was energy-efficiency tested,and the diagnosis analysis and transformation measures related were raised, which lay the foundation for the energy saving transformation of air conditioning system in the next. In allusion to the energy saving transformation of the main teaching building, the technologies of electric quantity breakdown and cold quantity measurements are introduced to key research the construction of the energy-consumption monitoring system. Further, based on the project pricing requirements, the cold quantity pricing scheme of the main teaching building is designed and verified.Based on the overall energy consumption analysis model and of method, total building energy consumption is analyzed year after year and month after month. The energy consumption characteristics are put forward and the causes are analyzed. Then, on the research and analysis of respective energy consumption of refrigeration season and typical air conditioning month and the respective energy consumption of air conditioning system day by day, the energy consumption indicators and characteristics are concluded.Building up energy-saving diagnosis analysis method which based on the partial measurement of air conditioning, based on the central air conditioning system operation and energy consumption monitoring data of the main teaching building, system operation condition quantitative diagnosis indexes are analyzed. Chilled water and cooling water temperature differences, water chillers load rate, operation performance coefficient COP and water system transmission coefficient are Researched and analyzed to evaluate of the air conditioning system operating conditions. The influence of different load rate to COP is researched. Typical day of air conditioning water chillers under a high load rate is chosen for hourly monitoring analysis on the central air conditioning system operation condition.Finally, through the contrast and analysis of the testing for the air conditioning system of energy efficiency before and after the reconstruction, the proportion changes of respective operation equipment of the total energy consumption are being compared to evaluate the energy-saving transformation effects.