Air-conditioning System Energy Efficiency Analysis And Renovation Research Of An Office Building In Guangzhou

With the development of China’s economy and the continuous construction of urbanization,the total area of public buildings and energy consumption are growing rapidly.Studies have shown that,most of the old buildings are high energy consumption buildings.Therefore,the buildings’ energy consumption problem has aroused more and more attention.In building energy consumption,the energy consumption of airconditioning system is accounting for a large share.With the improvement of indoor environment comfort requirements,the energy consumption of air-conditioning system is also rising year by year.Studies have shown that,according to the differences of building type,the energy consumption of air-conditioning system is accounting for 10% to 60% of total energy consumption.Therefore,to maintain the premise of thermal comfort,reduce the energy consumption of building’s air-conditioning system is an effective measure to ease China’s energy shortage and achieve the building energy efficiency.At present,due to the unreasonable design or operation situation,there are many problems in most of the public buildings’ air-conditioning system.such as,the design selection of chiller and pump is too large,the equipment cannot reach the rated efficiency,low water system delivery efficiency,the system appears "run leaking" and so on.Which makes the energy consumption of air-conditioning system is high,so this part of the building’s air-conditioning system is needed to energy-saving transformation,its energysaving potential is also very large.This article will take an office building in Guangzhou as an example,to make energy efficiency renovation for its air-conditioning system.At the same time,present the entire transformation process in a standardized and detailed way.Through analysis the various of existing evaluation indicators,to choose the optimal evaluation indicators for the system which is air conditioning system efficiency EERs,then,use it to assess the entire system.The EERs of the building is 1.85,the maximal value is 2.61,therefore,need to be modified.Then,through test and analysis the air conditioning system found that,the chiller is in a low load state for most of the time,the annual average COP is 4.5,the COP in transition season is only about 4.0;pump energy consumption is high,the pump annual power consumption accounting for 59% of the annual electricity consumption of chillers,and there is a serious phenomenon of large flow and small temperature difference in water system;air conditioning system lack of automatic control system,resulting in large system energy consumption and other issues.According to the existing problems of the system,the article put forward some renovation measures which meet the characteristics of the system,such as replacing the ordinary chillers to centrifugal magnetic suspension water chiller,installing some frequency equipment to pumps,deep cleaning the water system,installing service type energy management system,to renovation the system.And forecast the energy-saving effect after the transformation,through calculation,the cold station’s annual power consumption is 415000 kWh,annual operating power consumption will be reduced by 235000 kWh,energy saving rate is up to 36%,energy-saving potential is great.