Application of the hottest ugnx2 in the design of

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The application of UG NX2 in the design of main steam valve of steam turbine

I. Introduction

the long-term sustainable development of the national economy will definitely have greater demand for the power industry. After entering the 20th century, China's power equipment manufacturing industry has ushered in another spring. As a large enterprise of China's power equipment manufacturing, it must adapt to the new demand, open up an innovative situation, and drive industrialization with informatization, So that enterprises can make timely feedback according to the instantaneous changes of market demand, adjust product performance, meet customer needs to the greatest extent in the shortest time, and enhance product competitiveness. Based on the introduction of Westinghouse design and development technology in 1995, Shanghai steam turbine Co., Ltd. (STC) has started the project of establishing a large-scale steam turbine design and development platform since 2001, The combination of advanced design methods and manufacturing level with advanced computer cad/cae/cam runs through all links of steam turbine design and manufacturing, which greatly shortens the cycle of product development, design and manufacturing, continuously improves the performance and quality of products, changes the situation of developing a new product in the past 3 to 4 years, and creates considerable economic and social benefits for enterprises

unigraphics (UG for short) is a three-dimensional parametric software integrating cad/cae/cam. It is the most advanced computer-aided design, analysis and manufacturing software in the world. It is widely used in aerospace, automotive, shipbuilding, general machinery, electronics and other industrial fields. It mainly provides multilevel, integrated and enterprise level complete MCAD solutions including software products and services for automotive and transportation, aerospace, consumer goods, general machinery, electronic industry and other fields through its concept of virtual product development (VPD). Since our company introduced UG NX, it has been deeply loved by engineers and professional technicians with its advanced theory, strong engineering background, perfect functions and professional technical services, and has been applied to the actual development, research, production and manufacturing to the greatest extent, so that our company's technical means are in line with international standards, and continue to improve the design cycle and design quality of new products, And make our company produce high-quality and low-cost steam turbines a reality, and effectively participate in the international market competition

II. Overview of main steam valve assembly of steam turbine

main steam valve assembly is one of the most critical and important components in modern steam turbine. It is the gate of steam turbine inlet and plays the role of the last line of defense for the safe operation of steam turbine, that is, it plays the role of emergency blocking of steam inlet when necessary, and controls the speed of steam turbine when the steam turbine is started

Figure 1 actual product after workshop assembly

a steam turbine is equipped with two main steam valves - regulating steam valve components, which are installed on both sides of the high-pressure cylinder. Each component has a main steam valve and two regulating steam valves, which are combined in an integral casting. The opening and closing of these valves are controlled by hydraulic opening, spring closing and DEH, that is, they are controlled by their respective actuators installed on the valves

the main steam valve is of horizontal structure, and there is an internal bypass valve inside the main valve, all of which are single seat unbalanced butterfly valves. When the valve is in the closed position, the inlet steam pressure and the load of the compression spring will press the two valve discs on their seats at the same time. At the steam inlet of the main steam valve, there are two layers of filters - permanent filter and temporary filter, to prevent foreign matters from entering the flow passage part. After the turbine is initially started and operated for a certain period of time, the temporary filter installed on the outer layer can be removed

Figure 2 the workshop is hoisting the valve cover

the control valve is a vertical structure, which is controlled by an hydraulic servo motor. The hydraulic servo motor is directly installed on the upper end of the regulating valve. When the piston of hydraulic servo motor moves upward, open the regulating steam valve, and when it moves downward, close it. There are two steam leakage interfaces on the regulating valve stem sleeve, the high-pressure interface is connected to the steam exhaust of the high-pressure cylinder, and the low-pressure interface is connected to the steam seal cooler

the main steam valve - regulating valve assembly is fixed on the foundation with foundation screws through the support as the fixed dead point. This support can bear the force of the user's pipeline, maintain the position of the steam chamber and adapt to the thermal expansion of the component itself

III. application of UG NX in the design of main steam valve of steam turbine

the modern design method of steam turbine has changed from the design of single power unit to the design method of building blocks within a certain power range. As one of the important building blocks in the design of steam turbine, the main steam valve assembly with high technical content is composed of hundreds of parts with different shapes. The number of parts is huge, the structural form is complex, and the processing technology is high, The traditional two-dimensional CAD design technology, which uses computers to draw graphics instead of drawing boards, obviously cannot meet this new design method well. Instead, the powerful functions and excellent performance of advanced UG NX are used to realize the automation of design, ensure the rationality and accuracy of design, greatly reduce the design work and shorten the production cycle of products

Figure 3 Flow chart of three-dimensional model design of main steam valve assembly

the following discusses the unique characteristics of UG NX and its perfect embodiment in practical application through the design of three-dimensional model of main steam valve assembly

1. Excellent modeling ability

ug NX adopts hybrid modeling method to integrate solid modeling, surface modeling, wireframe modeling, display geometry modeling and parametric modeling. It can accurately define design products and support parametric feature design. Visual feature Navigator (MNT) reflects various dimensional and mathematical correlations formed between product model features, so as to effectively express the design intent of engineers and the basic characteristics of products. Through the advanced model, feature reordering and size driven functions, engineers add more flexibility in the design process, and effectively retain the product model data to meet the needs of product modification at any time

Figure 4 The three-dimensional model of the main steam valve designed by using the excellent modeling ability of the national or industrial standard UG NX, which also has no general basic raw materials

2 Excellent large-scale assembly performance (advance assembly)

UG NX assembly module provides top-down and down-top assembly methods, ensuring that the assembly model and part design are completely bidirectional related, simplifying the operation steps, reducing the demand for storage space, and enabling thousands of parts to be loaded and displayed in a few seconds, Lightweight small plane representation and wrap assembly can only load product parts that users need to modify and evaluate. Nx's component filter can establish some criteria, such as location function and similar attributes, to identify and load components in products to meet the needs of specific tasks, so that engineers can reduce loading time and screen confusion as much as possible while focusing on product level needs. Using the rich functions of assembly Navigator (ANT), load option, reference set, standard part library call and weight control, it is convenient for users to understand and manipulate the assembly structure, and also convenient for users to generate part lists (BOM) and previous use reports (where use)

Figure 5 Use the assembly Navigator (ANT) to completely express the assembly structure of the main steam valve assembly

Figure 6. Explosion view of the main steam valve after assembly

Figure 7. Semi sectional view of the main steam valve after assembly

3 Parametric, variable and serial design

the manufacturing of mechanical products is characterized by batch and serialization. The design needs to meet standards and specifications, so as to reduce costs. Using the powerful technology of UG NX wave, we can quickly develop new products from a common product structure. Wave technology automatically transmits design changes by updating related components and tools, which reduces the cost of design changes, greatly improves the repetition rate of design, and realizes rapid iterative tests and feasibility studies

variable design is aimed at serialized products, which can greatly improve design efficiency, reduce work intensity, difficulty and cycle, save cost, improve the accuracy of design drawings, and enhance the controllability of management. The work that can only be undertaken by professional designers can be replaced by general auxiliary staff, so that more designers can never accurately track the gauge change of the sample by manually moving the gauge rod; The three of them were liberated from the repetitive labor force and invested in the development of new products, which made our CAD design to a new level

figure 8 Use part family to establish factory standard parts, which greatly improves the design efficiency

4 The drawing module provides a complete automated tool set for the generation and management of engineering and technical drawings. The intuitive and friendly graphical interface of UGNX allows engineers to easily and effectively establish and manage high-quality, fully standard compatible part details and assembly drawings. Because the drafting function of UG NX is based on the two-dimensional engineering drawing obtained by creating the two-dimensional projection of the three-dimensional solid model, the engineering drawing is completely related to the three-dimensional solid model. Any change in the size, shape and position of the solid model will cause the two-dimensional engineering drawing to be updated, reducing the cost and time of drawing

Figure 9 Use the drafting module of NX to generate the two-dimensional engineering drawing of the main steam valve assembly

5 Innovative visualization tool

ug NX provides a wide range of rendering tools, adding surface color, material, texture and transparency to help users evaluate product principles and make design decisions. Through various types of lighting configurations, choose strong or soft shadows, set the foreground and background, create a real scene, simulate the environmental conditions of the product, more truly express the design concept, reduce the cost of the prototype, and bring the product to the market faster. This module has become an effective communication tool for product design between our engineers and technicians, colleagues, customers and suppliers

Figure 10 Visualization module simulates the real effect of main steam valve components

6 The independent cam solution

ug cam system provides a variety of professional solutions for the general machinery industry, such as high-efficiency plane milling, fine machining for castings and weldments, turning and drilling of large quantities of parts, etc. the processing of product features can achieve efficient automation to solve the problems of NC tool path generation, processing and processing verification

by using the efficient programming software UG Ca, the technical characteristics of the hydraulic universal testing machine produced by StarTech m make the product processing directly generate the processing program from the three-dimensional model, use the network database to select the appropriate processing parameters and tool parameters, reduce the intermediate links, and improve the work efficiency, while the machine tool connection and remote communication, the preparation and Simulation of NC program, and the database management of NC program are an organic whole, Jointly complete the functions of program communication, equipment management, programming, simulation, program database management and personnel authority setting, so as to make the equipment networking and program management scientific, so as to achieve safe and efficient production

Figure 11 Use UG cam to simulate drilling processing of main steam valve bonnet

7 Digital simulation technology (CAE)

UG NX CAE provides a comprehensive world-class digital simulation solution, which can help users avoid troubles in the process of product development. At the same time, it also supports conceptual design

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