Domestic Development Of High Pressure Bypass - Valve Body For 600MW Supercritical Units

High-pressure bypass-valve is an important working fluid governor valve of thermal generator set, Because of its specialty; high-pressure bypass-valve can not be replaced by general-valve special valves. At present, as the adjustment of national industrial policy, large thermal power units with high-performance and low-pollution are widely adopted. 600MW supercritical units have gradually become the main force units. At the same time, there are higher requirements for the safety of power plant units. Increasingly attention is paid to the function of mating high-pressure bypass-valve. With the development of 600MW supercritical unit high-pressure bypass-valve in this paper, we can not only improve the technical and scientific level of the high-parameter valve field in China but also end the phase that our country couldn't product this valve and should depend on importation. At the same time, there is a certain reference value for other work on the development of high parameters valve.This paper mainly discusses the structure design and optimize. At the beginning of the design, in order to cut the cost, we use functional cost analytical theory to analyze cost and identify cost control and performance optimization. Research and development is based on collecting a lot of information about the high-pressure bypass-valve includes the international and the native product and reading many article of high-pressure bypass-valve. When establishing the valve three-dimensional parametric design model, I make sure that the whole structure and the function module should services the function which this value will achieve. Give full consideration to the safety, structural simplicity and economy of valve.Valve is core components of the entire high-pressure bypass valve. Its strength directly affects the safety performance of the valve. The valve body bears thermal stress and pressure stress. In order to determine the region of stress concentration of the valve body, thermo-mechanical coupling analysis in ANSYS is adopted. Analysis shows that stress concentration phenomenon of valve design is significant and the maximum stress exceeds material strength requirements. In order to reduce body stress and make distribution of stresses tend to be more evenly, body structure must be improved.Optimize the valve body structure, basing on the conclusion, which is from finite element analysis. The parameter sensitivity analysis has been done in ANSYS-Workbench. Chose 7 parameters as design variables to optimize and analyze, with the greatest effect stress as the objective function. Use first-order optimization method to improve the initial design. Composing the parameters of the seven dimensions, whose sensitivity is larger, the number of tests is reduced and costs is saved. Finally, by optimizing the structure has been improved. Modified structure significantly reduces the max stresses in the three critical zones as to meet the security requirements. Then I could raise the performance of valve, save the material and cut down the cost.After determining the final design of the valve structure and manufacture physical prototype. Hydraulic test has been used to test the body strength and validate the rationality of design structure.