The Performance Study Of The Basic Meter On The DN25 Indoor Using Heat Meter

At present,the global trend of energy saving and charged by heat metering is imperative,thus we require a large number of household heat meters with excellent performance. But the technological level of the domestic heat meter is still quite lower than the foreign products, so it is necessary to research the characteristics of heat meter. In this paper, the study is focused on the structure of the basic meter, which based on a mechanical heat meter of DN25 and an ultrasonic heat meter of DN25 that have emerged on the market. Refer to the results of the research, this paper gives two optimizing project of basal meter and design a new hatch structure of the mechanical heat meter.The methods of the study in this paper include theory analysis and numerical simulation which is tested and verified by the experiment research. For the mechanical heat meter,the models of standardκ-ε, RNGκ-εand SSTκ-ωare used to calculate the inner flow field of basic meter, and the results are compared with the experimental. It is found that the model of SSTκ-ωis more adapt to the calculation of inner flow in the basic meter. This paper studies the influences of the size of hatch, the tip clearance, the entrance angle, the thickness of splitter on the chamber, the shape of splitter on the chamber and the number of splitter on the chamber on the meter's performance, which evaluate based on the factor K,the pressure losing and the flow patterns within the basal meter. It is found that the smaller hatch,the smaller tip clearance,the smaller entrance angle,the thicker splitter on the chamber,the airfoil profile of splitter on the chamber and the more splitter on the chamber can all lead to increase of the coefficient K and improvement of the heat meter resolution. Refer to the results of the research, this paper obtains an optimizing project of basal meter and a new hatch structure of the mechanical heat meter.To the ultrasonic heat meter,the model of LES which is widely used in industry is used to calculate the inner flow field of basic meter and it is also tested and verified by the experiment research. This paper studies the influences of the flow area,the size of the reflectors and the length of the reflection path on the meter's performance, which evaluate based on the factor K and the flow patterns within the basal meter. It is found that the smaller flow area and the reflectors and the longer reflection path are all lead to the excellent flow characteristics. Refer to the results of the research, this paper obtains an optimizing project of basal meter of ultrasonic heat meter.The methods of this paper are right and vivid which assisted by a lot of figures about inner flow. The research of this paper for the fluid characteristics on the mechanical heat meter and the ultrasonic heat meter provides the related base and direction for the design of the basic meter. It has made up for the vacancy of domestic field and it has some innovation in the inner flow field.