Research On Characteristics Of Vortex And V-cone Flowmeter In The Steam Measurement

Vapour is an important clean secondary energy, which own the larger proportionin energy consumption. But compared with water, electricity, gas and other energymedium, vapour is difficult to measure due to its unique and complex physicalproperties. Accurate measurement of the steam has been a difficult measuringproblem in the world. The measurement widely uses air or water instead of steammedium for traceability. Although this method has obtained good results, but don’treflect the real condition of steam flowmeter, because different medium will causemeasurement error. Steam flowmeter has low accuracy, on account of steamflowmeter tracing method is not perfect, and lack of the steam flow experiments ondetection, which is the important factor of restricting steam metering management andinstrument development.A set of standard steam flow installation has been developed by usingcondensation weighing method to deeply analyze the measurement characteristics ofthe steam flowmeter in steam medium. The device improves the origin of steam flowvalue transfer system, which is helpful to improve the accuracy of steam flowmeasurement. On this basis, vortex flowmeter and V cone flowmeter measurementcharacteristics have been researched on the base of the real steam test flow method.Combined with computational fluid dynamics and thermodynamics, the differences ofthe measurement characteristics of vortex flowmeter are obtained under differentmedium; the mechanism of the difference has been analyzed; which will bring in acertain error on measurement results has been found that the steam flow meter iscalibrated with water or air as the test media. Therefore, meter factor correctionmethod has been put forward by using water or air substitute the steam. The flow fieldof vortex flowmeter and V-cone flowmeter in different media has been simulated byusing CFD simulation.The main research work is as follows:Comparison experiment of vortex flowmeter in air, water, steam has been done byusing the measuring standard device. The results showed that the different mediumhas affected on the measurement performance of vortex flowmeter. According to thebasic principle of fluid mechanics and the Carmen vortex, the mathematical model ofsteam vortex flow meter has been created, and the correction method of instrument coefficient of different media conditions is put forward so as to build a theoreticalbasis for experimental study. The vortex flowmeter is analyzed in different mediumby using CFD simulation software.There is less research on expansion coefficient of V cone flowmeter in the air andsteam medium conditions, especially lack of experiment and theory analysis.Researches on coefficient of expansion have been carried out under different diameter,different βprototype in different media, temperature, and pressure by using water,negative pressure air, positive pressure air and steam device respectively. The V coneflowmeter empirical correlation coefficient in air and steam medium is analyzed. TheV cone flowmeter coefficient of expansion has been analyzed by using the CFDsimulation software simulation, the mechanism of the differences in different mediahas been analyzed and explained from the simulation flow field explains and theexperimental results are verified. The V cone flow expandable coefficient in air andsteam medium is prediction by simulation.The condensation weighing standard method of steam flow instrument has beendeveloped to analyze the pressure vessel, the condenser system and the commutator.And the design has been optimized by using the CFD simulation software.Technology index of the apparatus is tested and analyzed.