09-03-12 Topic — Application of CAD Technology in Heat Exchanger Design

I’ve read a book written by Dong Qiwu and Liu Minshan on the development technology of CAD systems for heat exchange equipment; it seems they are quite good at this in China

Dong and Liu were among the first to develop shell-and-tube heat exchangers; the specific level of advancement achieved by them is not entirely clear.

CAD is an excellent development platform, which enables the creation of many specialized software applications tailored for specific industries. For heat exchanger design, CAD’s greatest advantage lies in its ability to generate a wide range of parametric graphic libraries that meet the requirements of various heat exchanger standards. Additionally, certain calculations can be integrated into CAD, including those related to piping layout, weight, volume, and strength. As for heat transfer calculations, these are rarely integrated into CAD due to the relatively weak 3D design capabilities of CAD; therefore, such calculations have to be carried out in MDT. Our company, in collaboration with universities, is working on developing this module, which would allow heat transfer calculations to directly drive MDT-based 3D modeling, resulting in engineering drawings. We expect to complete 90% of this work by the end of the year. Regarding CAD development, I believe PCCAD from Tianhe is undoubtedly the best option in China, although it isn’t specifically designed for the heat exchanger industry. However, additional plugins can be used to complement its functionality. Another option for the chemical industry is HGCAD, which is already available commercially, though it has fewer functions. Among the tools available for chemical engineering, PVCAD, PVDESKTOP, and PVDS from the National Chemical Design Center are considered the best options. It’s also worth mentioning EPDRAW2000, which still has many users to this day. I really want to develop something in this area as well; work on it is currently in progress. However, in terms of driving mechanisms, too few functions are available in 2D formats – basically, only component-based approaches are possible, or those with very simple structures. For more complex structures, 3D-driven approaches are necessary. I prefer PROE; at present, after parameterizing the CAD components, I use PROE to achieve overall parametric modeling

Research on a Component-Based CAD System for Heat Exchangers Liu Minshan, Liu Qiyu, Dong Qiwu, Wu Jinxing (Center for Thermal Engineering, Zhengzhou University, Zhengzhou 450002, Henan, China) Abstract: In view of the problems existing in the development of CAD software for heat exchangers, a CBSD method for developing CAD software systems based on component technology is proposed by combining the UML modeling language. The process and characteristics of developing a heat exchanger CAD system using the CBSD method are described, and an example of developing heat exchanger software components using the COM standard is given. Keywords: software components ； Heat exchanger ； CAD ； UML ； COM? 1 Introduction Heat exchangers are energy-saving process equipment widely used in industries such as chemical engineering, petroleum refining, and power generation. They have complex structures, numerous components, and a lengthy design process with many steps. The combination of CAD technology and heat exchanger design has significantly improved the quality and efficiency of equipment design, as well as shortened the development cycle for new products. However, due to the high level of specialization required for the development of heat exchanger CAD software, existing heat exchanger CAD software is significantly behind the current state of development in computer application technology ； Also, due to the crises faced by the software industry itself, there are a series of problems in the development, maintenance, expansion, and upgrading of CAD software, which significantly affects its development and application. Software component technology is a solution proposed to address the long-standing issue of software development lagging behind hardware development. It fundamentally changes traditional software development approaches by creating a system in which various parties provide software components that work together in coordination, thereby enabling software reuse and robust updates. It represents a major trend in the development of the software industry. Applying the component-based software development concept to the development of heat exchanger CAD software is an effective way to technically avoid redundant development and address issues such as software maintenance. http://cache.baidu.com/c?m=9f65cb4a8c8507ed4fece763105392230e54f733649dc7150885ce1784642c101b7bb7e079755119968f613f57fa1841eaf23472200356b786cb9f4aaae1d4773bcd7a742613d71244c418dfdc3654d650e14d98dc0e93bde733e3b9a4d5c82220dd52756df0809c2a7003bb65e7653bf4a7e95f645b07cee827648f4e062288544aa13788f7436a108086ca2d4fd45da1766796b841b02913c504d4180c5542b74dc11f272727934b3089452a7593&p=97769a418d934ea85ab7f8604600&user=baidu 2 Overall structural design of the computer-aided framework design (CAFD) system for chiller units. First, after entering the cooling capacity, type of working fluid, and operating conditions, the compressor selection process is carried out; multiple compressor combination options are generated based on the matching of these parameters. Among the obtained compressor combination options, the one most likely to be successful is selected. Based on this selected compressor combination, corresponding compressor graphic modules are retrieved from the compressor series graphic module library in a PD graphical environment to carry out the preliminary layout design of the chiller unit. This step determines the spatial relationships between multiple compressors (or just one, in which case the next step is taken directly). Initial values for the length of the heat exchangers (condenser and evaporator) are then selected to provide the necessary data for further calculations related to the heat exchangers. Subsequently, using data such as cooling capacity, type of working fluid, and initial lengths of the heat exchangers, designs and calculations can be performed to determine other structural parameters of the heat exchangers, such as diameter, pipe diameter, wall thickness, etc. These key parameters determine the structure of the heat exchanger. By transferring these data to the heat exchanger parametric modeling module library, a framework diagram of the heat exchanger can be generated. This framework diagram is then inserted into the preliminary layout diagram of the chiller unit (which contains only the compressors), resulting in an overall layout diagram. However, generally, the overall layout diagram obtained in this way is not very reasonable; issues such as inconsistent spatial arrangement between compressors and heat exchangers or awkward shapes of the heat exchangers may occur. Thus, further modifications are required, such as adjusting the positions of the compressors, removing unreasonable heat exchanger frameworks, selecting new initial values for the heat exchanger lengths, designing new heat exchanger frameworks, and proceeding with another round of overall layout design... Repeating this process several times can yield a more satisfactory overall layout diagram, which represents the product framework. After obtaining each product framework, its cost is estimated. In this way, overall layout designs for each of the selected compressor combination options are carried out, resulting in multiple product frameworks that can be used for selecting the best option. 3 Research on CAD systems for heating pipeline networks and hydraulic optimization calculations. Chinese abstract: To improve the efficiency and quality of heating pipeline network design in the field of survey and design, this paper discusses the development of a CAD system for heating pipeline networks along with related optimization calculation methods, by comprehensively applying CAD technology and modern design theories, using AutoCAD 2000 as the platform. .... 4 The use of CAD technology for drawing a wide variety of heat exchanger schematics and design and manufacturing drawings with complex structures **increased the design speed and yielded good results. 5 combines the design of heat exchangers with the concept of computer-aided design to propose a systematic model for heat exchanger design. Considering the diversity of heat exchanger structures and the complexity of factors affecting heat transfer performance, it effectively addresses the issue of human-computer collaboration as well as the integration with the drawing software AUTOCAD. A concrete implementation of the air-cooled heat exchanger was carried out. The entire system is divided into two parts: the auxiliary design calculation part and the auxiliary design drafting part. It has good adaptability and is user-friendly. Yang Liming (Institute of Refrigeration and Cryogenic Engineering, Shanghai Jiao Tong University, Shanghai 200030)

CAD is an excellent design software, and it can be used as a design platform for various applications; for example, PD Soft is a piping design software that is based on a CAD design platform.

The application of CAD technology in the design of heat exchange equipment is mainly reflected in the following aspects: 1. 2D drawing: 2D drawing is the most common and widespread use of CAD technology, serving as a replacement for traditional manual drawing. 2 Establish a library of graphics and symbols: Based on the distinct characteristics of the system’s graphics, the most commonly used standard components and frequent graphics in heat exchange equipment design are created using parametric drawing methods and stored in separate libraries – one for standard components and another for common graphics. This allows these elements to be retrieved as needed, thereby simplifying the design process. 3. Parametric design: It refers to a situation where the structural shape of the design object is relatively fixed; a set of parameters can be used to define the relationships between dimensions. These parameters are directly related to the critical dimensions of the design object, and any modifications to the structure are driven by these dimensional values. Therefore, it is also known as parametric dimension-driven design. 4 Three-dimensional modeling: This technology enables the storage of an object’s specific shape and properties in a computer, thereby creating a three-dimensional geometric model of that object. 5 Design documents or generate reports. 6 is used for finite element modeling and analysis: Finite element analysis is currently the most widely used and mature CAE method in the field of engineering technology. 7 Database Management System: The databases involved in the CAD system for heat exchange equipment are primarily engineering databases. 8 CNC programming: The CNC programming method currently in use is mainly automatic programming, that is, the designed parts are extracted from CAD systems to enable direct automatic programming, which is the CAD/NCP integrated programming approach. 9 Optimization design: It includes two aspects: first, abstracting practical engineering problems into mathematical optimization models; second, applying numerical optimization methods to solve these models. In China, representative examples include the CAD software package for chemical equipment developed by the National Chemical Equipment Technology Center, VCAD 3.0 developed by Sinopec Corporation, the CAD software for floating-head heat exchangers developed by the Machinery Factory of Maoming Petrochemical Company, and the research, development, and creation of CAD systems for pressure vessels by the Hefei General Machinery Research Institute under the Ministry of Machine Building.

We use Autodesk Inventor to create the solid models; (of course, UGNX, SolidWorks, or PROE can also be used.) Their parameters are linked to our design’s Excel sheet. Facilitates parametric design. 1. According to the schematic diagram in GB150, establish a basic solid library for major components such as the shell, tube bank, and rear tube bank. Standard components such as flanges already have a standard component database. Modify the size of the EXCEL sheet as required for parametric design, to automatically generate the shell, tube bank, and rear tube bank. 2. The constraints are quite complex. 1) Front view, also connected using an EXCEL table; parametric design. 2. Special piping modules are used for the tube sheet and baffle plates, and programming is required for this. 3. Combine several major components to form the overall layout. This is relatively simple. (Of course, the parts list is generated automatically, including the weights as well.) 4. Import the heat exchanger drawing template to create a 2D CAD diagram (DWG file); some commonly used elements are already available in a block library, and they can be inserted by simply selecting them. This post was last edited by zjbook on 2009-3-29 21:15]