Research On Operation Evaluation System And Approach Of Central Air Conditioning System In Public Buildings

Recently,with the increase of scale of public buildings and the increase of average energy intensity,the energy consumption of public buildings has accounted for the largest proportion in Chinese building energy consumption.The energy consumption of central air-conditioning system is an integral part among the energy consumption of public buildings.It is found that the real performance of central air-conditioning system is not good by the investigation.Moreover,for its' proprietor,operation of central air-conditioning is uncertain.Therefore,it is very necessary to evaluate the operating state of the central air conditioning system,and then to diagnose the problems of the system operation based on this,and to realize the energy-saving and optimized operation of the central air conditioning.Based on the analysis of existing air-conditioning system evaluation and diagnosis methods,this thesis proposes that the characteristics of the system evaluation methods are less data,simple calculation and strong operability,etc.A well-operated air-conditioning system,its component equipment should be in good operating condition.Consequently,this thesis first evaluates the main facilities of the central air-conditioning system.The thesis compare different evaluation indicators of each air-conditioning equipment.According to the requirements of evaluation methods in this thesis,the indexes suitable for the evaluation of air-conditioning equipment are selected.Secondly,this thesis analyzes the energy efficiency from the perspective of cold source system,transmission and distribution system and terminal system,and establishes the evaluation criteria;then on this basis,AHP-entropy weight method was used to determine the index weight,and a comprehensive evaluation system for the operation of central air-conditioning systems in public buildings has been established.Then,the measuring parameters and methods of measurement used in evaluation system was analyzed,and determines the corresponding measurement methods based on the principle of simple operation and easy implementation.Finally,the central air-conditioning system in a university's medicine college in Zhengzhou was taken as an example,and makes an exploratory evaluation by using the constructed evaluation system.The assessment results indicated that the level of air-conditioning system energy efficiency was poor,and there are problems such as the small difference between the supply and return water temperature,low efficiency of circulating water pump,poor operation and maintenance of the system,etc.,which have great potential for energy-saving transformation.Further optimization was proposed in this thesis to solve these problems.