Simulation Of Flow And Temperature Fields On Quenching Process Of Large Diameter Thick-wall Gas Cylinder

In China, the CNG filling station network is gradual formation. the demand for fillingstation equipment has increased dramatically. Large diameter and thick-walled gascylinder is important storage equipment of natural gas filling station. The gas cylinder wasmade of chrome-molybdenum steel. As the cylinder has greater thickness and thehardenability is poor, therefore how to ensure uniformity and hardenability, to ensure theorganization is tempered sorbitic after quenching and the overall performance of theproducts meets the design requirements is the key of cylinder manufacturing. In thequenching process, because of the influence of the cooling capacity of quenching mediumand shape of the workpiece, the temperature and organizationa transformation inside theworkpiece is not uniform. Finally the workpiece would have internal defects and distortion.Application of CFD software in quenching process, the media flow field and thetemperature field of the workpiece could be coupled simulation. we can know thedistribution of the flow field and temperature field and the influence of various parametersto quenching.we can also improve our quenching equipment and optimize quenchingprocess.With the help of computational fluid dynamics software Fluent, I simulated the flowfield and temperature field with coupled method in quenching process. This articleanalyzes the flow characteristics and boiling heat transfer in the quenching process oflarge diameter and thick-walled pressure cylinder when the cooling water sprayed on thecylinder wall. And derived a formula of heat and mass transfer in boiling in accordancewith existing theories. Then write the UDF program. In order to save computing resourcesand improve computing speed, I design a simulation scheme depand on orthogonalexperiment.This article analyzes the influence of the nozzle diameter, the axial spacing,circumferential configuration and entrance velocity on quenching uniformity and internalpressure. And judges the sequence of the influence on test indicators for these four factors.I find that the influence of circumferential configuration for quenching uniformity is mostnotable. And I find the optimal combination of four factors. I establish the optimal combination model, and analysis the cylinder surface heat transfer characteristics, flowcharacteristics and pressure characteristics in quenching process. Obtained that surfaceheat transfer coefficient’s peak is on the jet stagnation, and slowly descend around thestagnation point with a circle.Overall the inner surface of the cylinder, the surface heattransfer coefficient is decreased from the bottle to the interior.