Study On The Calculation Of All-year Colligate Energy Effici-ency Ratio For Central Air-conditioning System

The typical air conditioning system includes chiller, chilled water pump, condenser water pump, open tower and terminal system. Optimizing chiller to improve their energy efficiency is only for the energy-efficiency labeling of apart of integrated energy efficiency level of the building air conditioning system, is the necessary conditions not a sufficient condition. As the article mentioned, chiller with high efficiency, which rated EER is large than 5 generally. But if air conditioning system operates in the partial load, small temperature difference with large water flow exists and it will lead to lower energy efficiency rate of the whole air conditioning system. Even the COP will be less than 3. So just emphasizing on the some parts of the system does not always means the improvement of the overall energy efficiency.From the entire air conditioning system, This departure includes the establishment of the various components of the energy system model, and then makes comprehensive analysis of the proposed operation ,which can improve the energy efficiency of the system of technical measures, the specific measures are as follow. First, establish three different functional types of building energy consumption model. It includes office buildings, shopping malls, hotels, establish energy consumption model of three different functions of these types of buildings throughout the year hourly load simulation by using DEST software. Different functions have different types of building load characteristics, analysis provide a basis for the selection of the unit. Second, establish the energy consumption of the chiller model. a different configuration of the entire chiller annual electricity consumption is got by setting different operating under typical load demand model calculations, basing on a typical chiller features variable conditions, and construction of dynamic load distribution , which can make a basis for the optimization of the system design calculation by comparing the relative selection of optimal solutions. Third , energy analysis of the pump frequency. The chilled water system and cooling water system energy efficiency is discussed by comparing the constant flow and variable flow chilled water system operation and the cooling water system's annual power consumption. Fourth, establish the calculation model of air-conditioning energy consumption of the end . The saving features of the exhaust heat recovery power . Discusse the energy efficiency of the exhaust heat recovery unit by calculated cooling load and the maximum annual total load reduction rates after using the exhaust heat recovery unit.This departure is major in the calculating the EER of the whole air conditioning system and making a software basing on the Microsoft Excel. This software can be used to compare the system scheme, and calculate the energy saving rate cooperating with the promotion of the Green Building design standards, then using the energy saving rate to just if it can meet the requirement of Green Building, the 60% energy saving rate.