Design Of Building Energy Efficiency Evaluation System

"Twelfth Five-Year Plan" put forward by our country includes24main indicators, Most of the implementation schedule is better than expected, but the four indicators, including nitrogen oxide emissions reductions, the proportion of fossil fuels in primary energy consumption, the amount of energy consumption reduction per unit of GDP, the amount of carbon dioxide emissions reduction per unit of GDP, their completion schedules is behind than expected. To calculate the energy consumption based on the per unit of GDP, China’s energy consumption per million dollars is,2.2times higher than the world average at present,2.3times higher than the U.S.,4.5times higher than the EU,8times higher than Japanese. That is in terms of energy conservation, our country still lags behind the developed countries in the world, and we should further strengthen the implementation of the energy conservation and emission reduction.Large construction is large in energy consumption, with the large buildings constantly emerging, building energy consumption increased significantly, while more than half of the energy consumption of buildings accounts is central air-conditioning energy consumption. Currently, large buildings are equipped with building automation systems (BAS), but most BAS systems prefer to monitor the equipments in the system independently, rather than monitor overall. Few BAS systems monitor the system as a whole, but the algorithm of monitoring are varied and uneven, whether the monitoring methods is reasonable or not needs to be evaluated."Building energy efficiency evaluation system" described in the text not only can analyze whether the existing control measures are reasonable or not, but also calculate the specific value of energy efficiency and provide the basis for subsequent energy saving transformation, so the buildings energy efficiency assessment has great significance.In modern building automatic control systems, power electronics technology, automatic control technology, network communication and computer technology has been developed rapidly, the products which use the technologies to produce continue to meet the growing environmental comfort degree needs and energy efficient needs. However, the concepts of environmental comfort degree and energy efficient are relatively vague, that means which environment comfort degree is optimal, and how much energy consumption per hour belongs to energy saving does not have a uniform standard. Building energy efficiency evaluation system can optimized the environmental comfort gradually, building energy efficiency evaluation system can assess the energy efficiency of each system for architecture which is installed BAS, and also it can access the overall energy efficiency of the system that under control, then, it can access the grade of buildings energy efficiency.The main innovations:1. The evaluation of central air-conditioning energy efficiency in buildings energy saving is premised on of people’s comfort degree, so the principals of the evaluation strategy is the people, we evaluate the energy efficiency according to the people’s feedback and feedback of the environment temperature, and if we control gradually according to the evaluation results, it will meet people’s comfort requirements eventually.2. The period of the conventional building energy efficiency assessment is about one to three years, analyze the evaluation results, and improve equipments correspondingly, to achieve the purpose of energy saving, but what time did the energy efficiency assessment start lowering cannot be determined. In this paper, a different approach to variable period as the time unit, when finding the energy efficiency lowering, you can observe and improve immediately, and the excessive waste of energy consumption avoid in result.3. In evaluation of the central air-conditioning energy efficiency analysis, the calculation of the past are specific to these three devices, including chilled water pumps, chillers, cooling water pump. in the paper, evaluation system target of building energy efficiency not only includes these three devices, but also includes cooling tower fan, fan coil units, lighting equipments, water heating equipments and so forth.