Abstract : Three-dimensional power plant design is becoming a trend. Taking the Ling'ao Phase II nuclear power project as an example, this paper introduces the application of three-dimensional software, analyzes some problems encountered in the process of use, and puts forward some targeted suggestions. Keywords : three-dimensional design; nuclear power engineering; application and suggestions Application of three-dimensional design in nuclear power project ZHANG Xin (Guangdong Electric Power Design Institute, Guangzhou 510000, China) 0 Introduction With the development of computer technology, three-dimensional design is receiving more and more attention. Using new three-dimensional technologies for design can not only present intuitive data models to people, but also delegate complex tasks to computers through a series of automated means (such as extracting material lists, collision checks, etc.), greatly improving production efficiency. This paper takes the Ling'ao Phase II nuclear power project as an example to introduce the application of three-dimensional design in nuclear power engineering. 1 Overview of three-dimensional design of Ling'ao Phase II The Ling'ao Phase II project is a megawatt-class pressurized water reactor nuclear power unit. Guangdong Electric Power Design Institute undertook the design work of the conventional island. This is the first time that the institute has independently designed a nuclear power project. In order to improve the design quality, three-dimensional design methods were fully used in the project. The main features are analyzed below. (1) Wide range of use. The three-dimensional software used in this project was provided by Bentley. The software consists of a series of professional software based on the microstation platform. The personnel involved in the nuclear power design basically regard the three-dimensional software as the primary design tool. Table 1 shows the specific software used by each profession. Each profession has invested a lot of manpower in the three-dimensional design. At present, the three-dimensional design has been adopted in all volumes of the thermal engine and hydraulic engineering professions, and the pipelines have three-dimensional models. Other professions such as electrical, thermal control and civil engineering are equipped with dedicated modelers, and the scale of personnel is significantly increased compared with other projects. (2) The application depth of three-dimensional design has been further increased. The application of three-dimensional design in previous projects was mainly to build pipeline models and produce construction drawings. However, the application in the Ling'ao project has been further deepened. Designers, checkers and others can complete their respective work on this platform. By conducting collision checks, collisions can be effectively avoided, greatly reducing design changes caused by collisions on site. (3) Three-dimensional design was also used for communication with external units. Nuclear power engineering has many interfaces and involves many manufacturers. For example, the main manufacturer of this project is ALSTOM. The design cooperation with this manufacturer also adopted three-dimensional design: directly incorporate its three-dimensional model into the whole model, and cooperate through collision detection, which made the design more intuitive. Through the application of three-dimensional design software, the cooperation between design units and manufacturers has become more and more intuitive and easier. (4) The application of three-dimensional management software is more in-depth. In the Ling'ao Phase II nuclear power project, the in-depth application of three-dimensional design also benefited from Bentley's Project Wise file management system. Through this software, a unified working platform is integrated, and design resources of various professions are shared on this platform. Through permission management, different people can share different resources. On this open platform, resources are fully utilized. The software also achieves seamless connection with other software. Designers can open various programs on this platform and perform various operations related to work. 2 Problems of three-dimensional design Three-dimensional design can improve efficiency, but compared with two-dimensional design, it also has shortcomings. (1) Modeling is relatively simple, but it is not easy to modify. The time required to build a pipeline model using PlantSpace is almost the same as that required to draw a pipeline using a two-dimensional method, but the three-dimensional design method is far less convenient than the two-dimensional design method for pipeline modification. Pipeline design is often modified frequently, especially in nuclear power engineering, where modification work accounts for a considerable proportion, so the three-dimensional design method is not advantageous in terms of drawing speed. (2) Stability needs to be improved. The more complex something is, the more difficult it is to maintain, and the same is true for three-dimensional software. It is often composed of multiple professional software, with a complex structure and a large memory footprint during operation. Once a problem occurs, it is difficult to find the cause, and it is difficult for non-professionals to solve, which affects the enthusiasm of users. (3) High data maintenance cost. Most of the problems generated in three-dimensional design are caused by the database. In order to reduce the occurrence of problems, manpower must be invested to maintain the database carefully. The complexity of three-dimensional software design makes data maintenance a tedious and error-prone task that requires certain professional knowledge as guidance, which increases the cost of data maintenance. (4) Uneven depth of three-dimensional design among different professions. Currently, 3D design for thermal engines has not only reached the level of drawing output but can also perform a series of tasks such as collision checks. However, for other departments, 3D design is still at a relatively shallow stage, and some are purely for modeling. The main reason for this is that different disciplines have different purposes for using 3D software. Some disciplines cannot use 3D drawing output, so 3D design may be purely for collision checks for them. It may be useful for thermal engines but not for other disciplines. [b]3 Suggestions for 3D Design 3.1 Continuous Exploration of 3D Drawing Modes[/b] The advantages of 3D design are obvious. Under the existing drawing methods and modes, 2D design still has its own characteristics. During peak construction periods, people often abandon 3D design and switch to 2D design. The main reason for this phenomenon is that the current drawing methods and the copying function of 3D design software are weak and the portability is poor. When using 2D design software to create drawings, it is easy to apply previous projects for similar planar drawings, but for 3D models, due to the differences in attributes and drawing methods, it is not easy to apply projects. Secondly, while 3D design is intuitive, its drawing output methods still need improvement. For example, the drawing output for supports and hangers differs between 2D and 3D. 2D output is a list of supports and hangers, while 3D output is an installation drawing. 2D output is quick and easily replicable, but the efficiency of using Support Modeler for support and hanger design is not yet fully realized. The transition from 2D to 3D drawing is different from the transition from manual drawing to 2D computer-generated drawing. The transition from manual to 2D computer-generated drawing did not involve a change in the drawing output method. However, the transition from 2D to 3D drawing involves a change in the drawing output method, which many people find difficult to adapt to, creating a significant contradiction. The crux of this contradiction lies in the drawing output method and the workflow. If 3D design continues to follow the 2D drawing output method, various problems will inevitably arise. Therefore, 3D design must have its own workflow. Only by continuously exploring 3D drawing methods and workflows can work efficiency be improved. 3.2 Software maintenance should be centered on the database. The database is the core of 3D software. This is mainly because all pipe fittings and supports in 3D design software are stored in the database. Secondly, in each operation, whether generating pipes or placing valves, it is necessary to connect to the database and extract data from it. Therefore, maintaining the stability of the database is the foundation for the stable operation of the software. Once the database has problems, 3D design cannot proceed smoothly, let alone work mode and other issues. In practical applications, some problems are often caused by the database, so it is necessary to maintain the database well. The author believes that the following aspects should be addressed: (1) There should be clear control over the permissions of the database, and only the database administrator should have the right to modify it; (2) Modification of the database should be carried out in a standardized manner, and the addition or deletion of data should be reviewed by someone; (3) There should be a dedicated person to maintain the database and update it in a timely manner according to the requirements of the designers to avoid affecting the progress due to the lack of database elements. 3.3 Strengthen Software Customization and Secondary Development Software is often geared towards the general public, and different organizations have different needs for software. To meet these needs, it is necessary to strengthen software customization and secondary development. In this process, the description of requirements is a crucial part. Only when developers have an accurate and comprehensive understanding of user needs can they develop software that meets those needs. Therefore, involving personnel with engineering backgrounds and familiarity with engineering will reduce development difficulty and improve work efficiency. 3.4 Establish Unified Standards and Standardize 3D Design Since many people are accustomed to the workflow of 2D design, they often don't understand what they should do or how to do it when transitioning to 3D design. The goals, drawing steps, and drawing objectives of 3D design are unclear. Therefore, to better promote 3D design, it is necessary to establish unified 3D standards and emphasize the standardization of 3D design. 3.5 3D Design Should Emphasize the Process 3D design is a gradual process; achieving a certain result requires considerable effort. Taking clash detection as an example, the clash detection at the end of each month requires a series of preparatory work. For instance, firstly, it is necessary to urge each discipline to modify the model according to the modification opinions of the previous month. Only after the model modification is completed can the clash detection be carried out. The results of the clash detection need to be sorted out, invalid collisions need to be removed, and valid collisions need to be classified by discipline and the collision locations need to be found. Finally, a clash detection meeting can be held to coordinate the cooperation among disciplines. 3.6 Software Research Should Be Strengthened For managers, 3D design is a new type of design model compared to 2D design. Under this model, it is necessary to explore new management models and methods, and these management models and methods are not much different for different 3D software. That is to say, software is just a tool, and 3D software uses similar management ideas. However, for software users, the ease of use of the software directly affects their work efficiency and mood. Therefore, the application research of the software should be strengthened. 4 Conclusion 3D design is becoming a trend. In order to enhance the competitiveness of enterprises, more and more companies are starting to use 3D software for design. 3D design is intuitive and highly automated, and the correct use of 3D software can improve efficiency. However, compared with 2D drawing methods, 3D design also has some drawbacks, such as difficulty in modification and high maintenance costs. To effectively use 3D design software, it is necessary to continuously explore the patterns of 3D drawing and constantly address the shortcomings of the software. Only through continuous improvement in use can the advantages of 3D design be fully realized, enabling enterprises to remain competitive.