| This thesis is completed with the background of SUFA technology industry CO.,LTD.,CNNC's plan which opens the market of high-end control valve for thermal power plant.And it also based on the combination of the company and Lanzhou University of Technology jointly organized for the master of engineering training.Today's modern industrial society,large capacity,high parameter development of coal-fired thermal power plant,control valve as an important auxiliary of main systems of power plant,the normal operation of the main power system plays an important auxiliary function.The 361 valve studied in this article is an integral part of the start-up system of supercritical boiler.The start-up system of supercritical boiler is an important part of the super critical unit.And the 361 valve is responsible for the system of water storage tank regulation.The 361 valve according to the opening instructions,adjust its own opening,thus the water level of the storage tank in the safe range.So it can ensure the safety of boiler super heater.The boiler stable and safe startup and low load operation and maintenance of.In this article,the following studies are carried out:(1)The main characteristics and operation principle of the starting system of ultra supercritical once through boiler are introduced,and the structure and control characteristics of the 361 valves are also introduced in this article.(2)According to the basic principles of fluid mechanics,Bernoulli equation and continuous equation theory,we derive the theoretical formula of 361 valve of the valve core sleeve orifice flow.Based on the basic equation of the automatic control,the characteristics of the 361 valve control mechanism are analyzed.Draw a proportional control SAMA chart(control logic diagram).(3)With the aid of the commercial software works flow and its plug-in simulation Solid,as well as commercial software ANSYS,the three-dimensional model of the 361 valve finite element analysis.The internal flow of the valve core was analyzed,and the changing law of the flow under different conditions was studied.The rationality and correctness of the theoretical calculation are verified.(4)This thesis will design of a set of 361 valve drawings,and make a production of a prototype,the flow characteristics of the test,to further demonstrate the correctness of the theoretical analysis.If someone wants to develop such products,this article provides some reference.This article can also be reference of the power plant which to be responsible for the production and operation of the system and maintenance engineering and technical personnel. |
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