Method Of Predicting Cooling And Heating Load Of Regional Buildings In Planning Stage

China is in the stage of rapid development of urbanization,and the regional energy supply is a way to undertake the demand of cooling and heating load in the area.Estimation of energy station capacity and evaluation of integrated energy applications are needed in a planning area,which based on load forecasting.Due to the planning stage,the specific architectural design has not yet been determined,the information about the load is limited.As a result,the incomplete construction information affects the accuracy of load forecasting,which is the biggest difficulty for regional building group load forecasting.In this situation,the area index method is widely used in the current load estimation.In order to ensure the safety of the operation process,designers usually overestimate the design load,resulting in the actual process operation load is always greater than the capacity of energy station installed capacity.In order to adapt to the characteristics and requirements of load forecasting in the planning stage,this paper has done the following research:Firstly,the typical buildings classification of the region in planning stage is put forward to determine the composition of the regional buildings.In order to avoid the choice of simultaneity usage coefficient,the load of the regional buildings is formed by the hourly superimposition of loads of different types of typical buildings.Bayesian theory is applied to revise the predicted load so that the hourly load values is more close to the actual situation.And the geometric parameters,thermal parameters and internal disturbance parameters of each type of typical building are determined by using both of the industry specification and Monte Carlo simulation.Secondly,the calculation method of each single load of typical building is determined.About the load for non transparent enclosure structure,‘the non steady state calculation and double layer equivalence principle' is used to calculate the hourly load in winter and summer.For other kinds of load,the load factor method is used for hourly calculation.Thirdly,the difference of heating load in intermittent running buildings,in winter,is studied and some suggestions are put forward for the calculation of intermittent heating load.Finally,because the input parameters of energy consumption simulation software are various and difficult to obtain accurately in the planning stage,a program which is based on the MATLAB software for predicting regional buildings load at the planning stage is compiled.Besides,the initial conditions needed for load forecasting are reduced through the establishment of database.Based on the above content,an example is used to show how the prediction program work.In addition,the Bayesian theory is used to revise the load predicted by the program.The results show that,compared with the measured load data,the error of the load forecasting method mentioned in this paper is 17.43%.In addition,after the correction of the Bayes theory,the error is reduced by 6.33%,and the error of area index method is 17.91%.It can be seen that the calculation method in this paper can predict the load of the planning stage more accurately,and provide more reliable basis for the later capacity sizing and energy planning.