Study On Impact Of Climate Change On Heating/Cooling Energy Consumption And Outdoor Design Conditions Of HVAC Based On Climate

The relation between climate and energy is one of the hot issues which government and scholar all around the current world pay close attention to.On one hand the development and utilization of energy influences climate,on the other hand climate change influences the consumption of energy too.Undoubtedly,it is the most urgent environmental problem that we face that the global climate becomes warm.Therefore, it is necessary to study on the influence of climate change on heating and cooling energy consumption.This dissertation has obtained the original meteorological data in the past 40 years (1961-2000) that stand of 194 weather stations from the National Meteorological Center.According to the district of "thermal design specification of civil building", use the techniques of degree-day method to analyze the China's climate change of recent decades and impact of climate change on winter heating and summer cooling energy consumption.On the basis of analyzing the general rules the climate change, based on the theory of probability and mathematical statistical methods,established a statistical model of extreme temperature with Gumbel distribution.Carried out the study on heating,air-conditioning outdoor design parameters under different guaranteed rates,calculated energy consumption under the extreme temperature.The innovative work and main conclusions are listed as follows:(1) Through the statistical analysis of temperature changes of the major cities in 1961-2000,obtained the tendency law of average temperature,heating degree days HDD,air conditioning degree days CDD and the relevant correlation between the average temperature change and HDD and CDD change.According to the statistics trend equation obtained,the number of degree days in future can be predicted.(2) Adopting the techniques of degree-day method,studied the impact of temperature change of typical cities and each zone on winter heating energy consumption.The main coverage and conclusions are as follows.1) There are closely correlations between heating degree-day and winter average temperature.The change rate of heating degree-day and each month of winter(December,January,February) were shown a good linear correlation.2) Through analyzing the established heating energy assessment model of each thermal zone,found that the impact of temperature change on the heating demand of each thermal zone are different.When the temperature change 1℃,the change rate of energy consumption of hot summer and warm winter zone and mild zone are larger than that of cold zones and hot summer and cold winter zone.3) Take Beijing as an example,carried on research of relation of unit area heating sales volume and that heating degree-day.Found that the linear correlation of the two is prominent.4) Warm winter had significant impact on heating energy consumption.(3) Adopting the techniques of degree-day method,studied the impact of temperature change of typical cities and each zone on summer cooling energy consumption.The main coverage and conclusions are as follows.1) There are closely correlations between cooling degree-day and summer average temperature.The change rate of cooling degree-day and summer average temperature were shown a significant linear relationship.2) Through analyzing the established cooling energy assessment model of each thermal zone,found that the impact of temperature change on the cooling demand of each thermal zone are different.When the temperature anomaly changes 0.1℃,the increasing degree of cooling energy consumption of each thermal zone is different.3) Take the electricity consumption in Shanghai for example.The relation between outdoor average temperature and the electricity consumption was studied.The results showed that the average outdoor temperature and power consumption has a good linear correlation and the linear regression is highly significant.4) Taking a certain construction of Xi'an as an example,analyzed the relation between the air conditioning energy consumption and outdoor temperature. The results showed that the heat loss of the build envelop was increased by an average of about 22%when the outdoor average temperature of air-conditioning raise 1℃.(4)Using climatology,probability theory and mathematical statistical methods, on the basis of the original meteorological data of China typical cities,introducing the frequency analysis method,establish the extreme temperature statistical model by using Gumbel distribution.Achieved the calculating formula of the frequency of extreme temperature and the probability distribution curve.The curve was in good agreement with the measured data and passed through the testing,of a significant level of 0.05.The testing result showed that adopting the Gumbel distribution to match the extreme temperature is reasonable.(5)Basing on statistical models of extreme temperature,built the simplified normal distribution model of outdoor temperature for each thermal zone.Obtained the relevance of the equation of the ensure ratio and the return period of outdoor temperature.The main work and conclusions are as follows.1)Through calculating the temperature value of summer daily average extreme temperature,winter daily average extreme daily,summer extreme temperature and winter extreme temperature, obtained the statistical value of extreme temperature of different return period.2) According to the extreme temperature statistical model,established normal simplified model of heating,air-conditioning outside temperature.The results showed that the simplified model for calculating normal value has a good match with the existing norms of HVAC statistical method.3) Analyzed the trends and changes in the law of guarantee rate of heating and air-conditioning outdoor temperature at different return period.Given the quantitative formula of experience.4) Took a building in Beijing for example.Wrote program to calculate the building energy consumption changes at the temperature of different return periods.The results showed that,with the temperature increase from the normal value to once in hundred years,the heat loss of building envelop also increased rapidly.Therefore,during the design of air-conditioning the extreme weather conditions should be considered.Through the work of this dissertation,reveals the climate change laws and the impact of climate change on heating and cooling energy changes.The study of this problem is helpful to determine the concrete condition of the impact of climate change on energy consumption.Not only can master the energy demand change law under normal climate condition,but also can forecast the energy demand under abnormal climate condition.It can offer the reference to the administrator and offer the theory basis of optical and energy efficiency design of heating and air conditioning design.Besides,it will be a guide for the relevant research.