| Today, the abnormal changes of global climate is becoming more and more frequent, in the construction industry and in the field of HVAC, people become more and more aware of the significance of outdoor air parameters on the building load computation. With the continuous deepening of the construction of the load calculation, it is found that the results of building load is too large to cause the selection of HVAC system equipment and the main reason of the building energy consumption is too large. Therefore, in the promotion of building energy saving today, development of a set of dynamic load calculation to guide the equipment selection of meteorological data is very necessary.At present, the load calculation method has changed from the original static calculation to dynamic calculation, and the design code of our country also explicitly requires that the dynamic load calculation must be carried out. The common types of meteorological data are also carried out a detailed comparison, in the design and application of actual engineering in our country, "typical meteorological years" which is widely used in is a combination of 12 monthly meteorological data from different years and be neither hot nor cold, only representative meteorological data, but the air conditioning equipment selection need not guaranteed rate data. If "typical weather year" is used to select equipment, there will be a long time cannot meet the design temperature and humidity. There are even some design personnel in the calculation of hourly load with the design day 24 h of the meteorological parameters. Therefore, it is not appropriate to use the existing "typical meteorological year" data to calculate the dynamic load of building and to guide the selection of equipment.On the basis of the previous studies on the "extreme weather years", the optimization of the minimum structure of the "extreme weather years" is studied. It generated a "ten day", "day", "time" as the smallest unit of the "Extreme weather years". By analyzing the "time" as the smallest unit of the "extreme weather years" data is the most extreme. The outdoor air computation parameters does not guarantee rate are analyzed, China's outdoor air computation parameters does not guarantee rate was expressed in hours or days. In order to allow designers to choose the appropriate parameters according to the actual situation, this paper identifies three levels of non-guaranteed rates: 1%, 0.5%, 2%, and the generation method of the "design meteorological year" for equipment selection.In Harbin, Beijing, Chongqing, and Guangzhou from 1986 to 2015 years of a total of 30 years of hourly weather data for the foundation, using MATLAB software programming, three levels of non-guaranteed rate of "design meteorological year" for the four levels of energy consumption simulation and equipment selection are generated respectively and compared with the "typical meteorological year". Found in the lower latitudes of the city, the greater the difference between the design weather and the CSWD winter weather data. The average monthly mean temperature difference between the two kinds of meteorological data in Harbin is 6.1; the average monthly temperature difference between the two kinds of meteorological data in Guangzhou is 9.2, and the mean temperature difference is about 8 degrees in summer months.In this paper, a dynamic energy consumption simulation software e QUEST is used to simulate the energy consumption and load analysis of an office building in Chongqing area, with "typical meteorological year" and "design of meteorological year" data into the simulation of building all year hourly dynamic loads, by comparing the findings:(1)In the "design of meteorological year" under the construction of the high load time increased significantly, the unit 74.7% running time is between the load in the 600~1800kW; and under the "typical weather year", the unit 80.6% running time is in the load between 200~1200kW;(2)Compared with the typical meteorological year, the design of the winter heat load of the building under construction in winter increased by 606.4kW, the peak growth rate was 62.4%; the peak summer cold load increased by 496.9kW, the peak growth rate was 30%.In addition, in the actual engineering design, most of the HVAC designers usually use the cold load coefficient method to calculate the cooling load of the air conditioner, According to the cold load coefficient method, the maximum value of the cold load is 2492 kW, and the heat load is 1620 kW.The use of "design meteorological year" under the construction of the annual dynamic load can be effective equipment selection and reasonable match. Taking a project as an example, according to the load size and the distribution of the law, select a large one small two units, when the building is in a low load gradient, open the small unit; in the middle of the load gradient, open large units; in a high load gradient, while the two units open. This can make the unit has been operating under the high efficiency of 80% ~ 40% load, can be achieved in 84.7% of the units in the summer for cooling time is in efficient operation. It both improve the energy utilization, and save the initial investment of 280 thousand Yuan. For winter unit operation analysis can get: unit in winter 82.4% of the cooling time is in efficient operation.In the summer, when the centrifugal chillers do as the cold source in winter the use of boiler make source, using "design weather was under construction throughout the year hourly dynamic load data, a reasonable choice of units, according to the distribution of the size of the building load, timely open suitable air-conditioning host, the unit in the summer for 80.7% of the total cooling time in efficient operation. Compared with the cold load coefficient method of equipment selection, part of the unit can save the initial investment of 50 million yuan or so. |
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