Simulation Study On The Structure And Principle Of Shunt Type Heat Meter

With the implementation and constant improvement of the central heating in China, the household metering way of heating charging will be more and more widespread, basically each heating user needs to install their own calorimeters. This will lead to the large demand for calorimeters in China, especially the heat meter with high measuring accuracy and low cost has a broader market. Objectively speaking, there are certain gaps about the technical level between the current heat meter in China and imported products, the techniques need to be improved, especially to improve the measurement precision of the heat meter and its universal applicability and reliability. At the same time, because the water quality in domestic heating system is worse, this can cause the damage of measuring instrument. This paper represents a new shunt type of heat meter structure model, using the related theory knowledge, through mathematical modeling, simulation analysis software of ANSYS, FLUENT, analyzing the fluid flow characteristics inside the shunt structure base table of the shunt type heat meter, and optimizing the structure of the related analysis about the temperature inductive elements. Concrete research contents and conclusions are as follows:(1)This paper aims at the internal flow field at the shunt type base table in this kind of split type heat meter, using the fluid of RNG k-e turbulent model, through establishing the mathematical model of different eccentric flow of the eccentric Angle and the opening size. After analysis and comparison the results of numerical simulation, it can be seen that opening size and the speed change curves of many groups of eccentric flow deflection Angle model are approximate linear curves, conforming to the designed working principle about the structure of the heat meter shunt, validating the feasibility of shunt structure design principle about the shunt type heat meter. Meanwhile, it optimizes the simulation analysis to the design of eccentric flow structure, at the final it will design the eccentric angle of the eccentric flow to 39 °.(2)Though analysis of simulation results about flow field, it obtains when the opening of eccentric flow is small, the speed of the flow field is almost zero, at this time it has nothing to do with the eccentric Angle of eccentric flow channel structure, so it is concluded that opening regulating range of the eccentric port has failure area. Through further analysis, it determines the effective range of the eccentric flow regulating opening changes of the shunt type heat meter(expressed as a central Angle eccentric sprue size): 4°-18°.(3)This paper also studies the thermal deformation structure performance parameters of the shunt type heat meter. Through theoretical analysis for the four factors that may affect the performance of heat distortion of temperature sensing elements the thermal deformation temperature difference between the sensing element(including structural stability of the thermal deformation of the metal spiral cross-sectional shape, metal spiral heated area, metal spiral thread angle and temperature of heating hot water), temperature sensing element(metal spiral thermal deformation structure) is conducted to a series of heat- structure coupled modeling and simulation, and the test results are valid. Through the study on thermal expansion deformation of different metal materials, we advised to choose metal platinum as the thermal deformation of materials. The optimized structure of bimetallic screw is designed to: the cross section of male thread is regular triangle, thread Angle of the upper threaded rod is 5°, thread Angle of the lower threaded rod is 2°.(4) Through further analysis to compare the thermal deformation simulation data, it is concluded that: when the runner entry angle and the difference in temperature of return water opening increase per 10 ℃, the spiral bar of thermal deformation by stressing distortion turns about 1°.Through the Variable speed regulation of gear mechanism, it drives rotating sleeve rolling, changes the impeller rotating speed, and then adjusts the port opening size to revise the caloric value caused by the inlet and return water temperature difference.The conclusions of this article have important guiding significance in the structural parameters of the shunt type heat meter for further optimized design, through comprehensive numerical simulation to the structure and principle of shunt type heat meter.