Coupled Thermal Analysis And Research Of High Temperature And Pressure Ball Valve

Most of thermal power system equipment in high temperature and high pressure in the harsh conditions for a long time, the valve as one of the auxiliary equipment of power system, not only in the process of workin g under high pressure and temperature, but also by the high-speed flow scouring and corrosion medium, so the power station valve performance requirements are very high. Th e paper discusses the ball valve under the coupling action of temperature and pressur e load stress distribution and strain of the situation. Design can be obtained through the scale conversion temperature pressure ball valve under the actual working condition of the corresponding temperature and pressure, based on Fourier heat conduction d ifferential equation of heat transfer process was calculated under actual working condition, the working condition of high temperature and high pressure ball valve on the standby and operating conditions of temperature fi eld is solved,with the aid of finite element analysis software of ball valve assembly body under the action of medium pressure generated by the equivalent stress under the effect of thermal coupling field with the analysis of the equivalent stress of the concrete, and the abrasion of valve core under different opening of do the discussion analysis, the conclusion has certain guiding significance to the design of power station valve.(1) It make a detailed force analysis for ball valve, calculation of valve sealing surface forces and valve sealing pressure ratio, and to check the strength of the main bearing parts.(2) The ball valve under the standby condition and operation conditions of temperature field, temperature field will get as load applied to the structure of ball valve, the coupled thermo-mechanical analysis, get the ball valve under the effect of thermal coupling of equivalent stress; Under the action of the ball valve in only by medium pressure, static structure analysis to get under the coupled action of stress field and thermal stress field, thermal stress and compressive stress has a certain offset function between; Iterative solution of temperature and the maximum equivalent stress of fourth order spline interpolation function, the temperature field and stress field of the critical condition of mutual influence.(3) In the thermodynamic coupling field while under the function of equivalent stress reduced, but the structure of the strain rather than what it once was, in order to ensure that the valve has good sealing, goal-driven on strain of the largest sphere structure size optimization design, the optimized structure under the effect of thermal coupling field of small strain quantitative change a lot, to improve the sealing performance of the valve.(4) The ball in vitro coating can not only improve the ball hardness, improve the effect of surface roughness, coating and the sphere model, respectively, in this paper, the analysis of assembly, the thickness of the coating can be obtained on its structural strength curve, found in the actual working conditions for the best thickness of the coating in vitro.(5) The ball valve in the process of operation, the opening of the valve core of different affects the flow velocity of medium, in turn, affect the surface wear rate. Under different opening of valve core wall wear rate and internal medium flow numerical simulation, it is concluded that with the increase of test of the opening of the valve core, surface wear rate and medium velocity decreases, and surface abrasion area position will change, wear surface shape by the beginning of the strip into the final point and block.