Research On The Thermal And Intensity Calculation System Of Impulse Industrial Turbine

Industrial steam turbines are characterized by diversity of uses, so they need to be designed and manufactured by non-standard method in order to meet the special needs of users. Industrial steam turbines can be divided into two types according to their working principles: impulse industrial steam turbines and reaction industrial steam turbines. A design technology, which uses modularization technology and CAD for the design of static part and flow part of the turbine, had been adopted in the design of reaction industrial steam turbine, and its products' performance and quality had reached international advanced level. Impulse industrial turbines were designed by manufacturers themselves. The design specifications of impulse industrial turbines were not as rigorous modular and serialization as reaction industrial steam turbines. The integration degree of thermodynamic design procedure of impulse industrial turbines was lower than reaction industrial steam turbines. In the field of software used for computer-aided design, there were some difficulties, such as too many parameters need to be imported, the versatility of the software was not strong; the design of user interface was not humanity, and so on. To solve the above problem of thermodynamic calculation software of impulse industrial steam turbines, a calculation system that can accomplish thermodynamic and intensity calculation expediently and fleetly was developed in this paper, based on the analysis of thermodynamic and intensity principles .The research work of this paper include the following content:(1)Calculation arithmetic of thermodynamic and intensity of impulse industrial steam turbines were researched. The calculation methods of design flow at all stages for industrial extraction turbine were analyzed, and arithmetic models were presented. The principles and advantages of thermodynamic calculation that used in the varying operating condition were researched. Thermodynamic calculation arithmetic of off-design condition for supercritical velocity stages was analyzed, and the improved calculation method which is propitious to the calculation convergence was presented.(2)The thermodynamic and intensity calculation system of impulse industrial turbines was developed based on Modularize Modeling method of object-oriented. The thermodynamic and intensity calculation characteristics of different types of industrial steam turbines, such as condensing, backpressure, condensate-pumping and back-pumping steam turbine, were analyzed in this paper. Procedure modules were programmed with object-oriented programming language C++, and a system that can combine modules into system was established, so the calculation system can apply to thermodynamic and intensity calculation for different types of industrial steam turbines. (3)This system integrated thermodynamic and intensity calculation into one platform. Intensity calculation system provided a security test platform for the thermodynamic design and varying operating condition. Besides, the unit without thermodynamic calculation can also be calculated in the intensity calculation system.(4) Database was used for data management. Geometrical data of steam turbine flow part, material performance data, and data of calculation curve and graph were stored in Access Database that is conducive to the reunification of the data management.(5) The principles and model of object-oriented software testing method were introduced. The calculation system was tested by class testing, class group testing and system testing under the guidance of object-oriented software testing method. Finally, several application examples of system testing were presented. The results of software testing showed that thermodynamic and intensity calculation system of impulse industrial steam turbine had achieved the expected function requirements.