| The averaging-velocity tube flow meter is widely used in the large diameter flowmeasurement in petrochemical, power, metallurgy, coal mine industries due to its simplestructure, easy installation, removal, low loss of unrecoverable pressure and the long-term use ofhigh precision characteristics. In this paper, the150mm-caliber averaging-velocity tube flowmeter for mine gas is taken as the study object. Based on numerical simulation and experiment,the main effect factors of the averaging-velocity tube flow meter flow coefficient are analyzedusing orthogonal test and overall balance method. By Further analysis of flow coefficient and itslinearity, a new structural parameter for averaging-velocity tube flow meter is obtained, whichhas steadier and lower flow coefficient. The main contents of this paper are described as follows:1. First, The real-flow test for the model flow meter is carried out to investigate thedifferential pressure and flow coefficient at different flow rate, and the experimental results is thebasis for verification the correctness of numerical simulation.2. In order to save computing resource and time, the three-dimensional model is simplifiedto two-dimensional cross section for the simulation for the symmetry of model. Based on theresults of numerical simulation and experiment, the numerical flow coefficient and pressuredifference for four two-dimensional cross sections of averaging-velocity tube flow meter arecontrastively analyzed. The two-dimensional cross section is determined which can be used tosimulate the performance of flow meter instead of the three-dimensional model.3. Based on orthogonal test method, the parameters of the averaging-velocity tube flowmeter are synthetically considered, which are front radius, the length, width and angel having theinfluence on its performance. Three levels of each parameter are chosen, and multi-group modelsare numerically simulated and analyzed. Two geometric models are obtained respectivelycorresponding to optimal flow coefficient and linearity. And new structural model having theoptimal comprehensive performance is obtained using overall balance method, when flowcoefficient and its linearity are both considered. At last, the internal flow field and performanceof original and optimal models are comparatively analyzed.4. The influence of different installation angle on the performance is analyzed for the optimal averaging-velocity tube flow meter at three conditions, when the total pressure holesaxis to the flow direction is0degrees,3degrees and6degrees. The influence law of installationangle on its performance is obtained based on the results of numerical simulation at everycondition. |
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