| In recent years, the energy consumption of building is higher, the proportion in total energy consumption in the possession of society is becoming more and more. Along with our country have issued various policy in the direction of building energy efficiency, energy saving renovation work of the existing buildings started in a wide range of the country. Energy-saving renovation measures for different energy system, also emerge in endlessly. The centralized air conditioning system as the main energy dissipation system in the whole building,have became the focus in the energy conservation transformation object,and the chilled water pump energy consumption occupy larger proportion in the air conditioning system,so energy-saving reform focus on the chilled water pump became one of the main means.As the application of frequency conversion technology, chilled water pump with frequency conversion system have became a hot choice for many energy conservation service company,but in the current reform process, many buildings in the late transformation did not get the expected effect of energy saving, and even some buildings equipped with frequency conversion system came out some problems, such as air conditioning refrigeration effect is not good.Therefore, how to apply frequency conversion to chilled water pump for reasonable, how to consider performance parameters in the application of variable frequency changes, and how to calculate the energy consumption before and after the transformation is the urgent problem to be solved.The thesis puts forward the study based on those ideas.The first part is the analysis of the present situation of the chilled water system, the research content including water chiller efficiency, temperature difference of chilled water system.The second part takes the pump running pipeline characteristic curve and the water pump performance curve as the research object, to get the determination of variable frequency pump operation point; Analysis the energy consumption calculation method of variable frequency pump, to get the main influencing factors of the energy consumption and the influence degree.The third part is the analysis through the actual test parameters, to get some conclusions about frequency conversion control mode, the pump speed limit and so on.Therefore, around the three parts above, the main tasks as follows:Choose three different types of building with chilled water system in chongqing for data analysis, contrast some parameters such as the COP,temperature difference with the standard, to get the common problems of chilled water system during the operation.For temperature difference control and pressure difference control of variable frequency operation, set the actual pump running parameters to illustrate the two flow control mode of pump calculation method of the energy saving and energy saving effect analysis.Set up a pump performance test platform, use the pressure difference as the control set, test the pump performance parameters, such as the input power and comprehensive efficiency, concluded that the change trend of performance parameters under different pressure difference control values, and also concluded that the selecting principle of differential pressure control values.Choose a typical mall building to analysis, compare the power consumption of chilled water pump, indoor temperature and humidity of operating fixed frequency and variable frequency condition, it is concluded that the problems and solutions in temperature difference control of the chilled water pump frequency conversion.Through the above research,the thesis provide a support of theory and the measured data for the application of pump frequency conversion, and make a detailed analysis focused on the calculation method for energy consumption of variable frequency transformation, energy consumption influence factors and influence level, the selection of control mode and so on. |
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