Research And Development On CAD Of The Heat Exchangers

Heat exchangers are the important apparatus for chemical industry. Floating-end heat exchanger is the widly used type of the heat exchangers. The characteristics for this type of heat exchanger are various standards, different shapes, multi-usefulness, completed specifications and same structure but large changing range of sizes for same series. By means of developing the database and drawing libraries, parameterized designing of pipe group units, the CAD system for floating-end heat exchanger was developed base on the theory of fixed patterns with flexible sizes.At the beginning of the paper, the characteristics of the heat exchangers and the current situation of their CAD are analyzed. The design procedures are summarized and the total structure for floating-end heat exchanger CAD is presented. This system consists of three modules such as the calculations for type selecting, pipe setting, and automatically generating for parts and assembly drawings. In the selective calculation module, the calculations of heat exchanger design, the analysis of pipe setting patterns are combined with the database so that the selective calculation sub-system is developed. Considering the factors such as uniform flowing of the fluid, smaller inner radius of the shell, the well heat exchanging effect and saving materials, the pipe setting module is developed based on the designing data. In the module for automatically generating parts and assembly drawings, the database of pattern sizes and the drawing libraries are established according to the classifications and series. The theory of fixed patterns with flexible sizes is used and the sub-systems of automaticall generating for drawings andpipe group parameterizing design are integerated. In the end of the paper, the development of the software is introduced and an example for floating-end heat exchanger design is given to show the usefulness of the system and the effect.The method presented in this paper makes use of database to save and manage the standard sizes data and makes use of drawing libraries to save and manager the parts and assembly drawings. The theory of fixed patterns with flexible sizes is used to generate the parts and assembly drawings. In this way the CAD for floating-end heat exchanger is realized. The software described in this paper is able to solve many problems in the floating-end heat exchanger CAD. The development method is universal in this field. It has important reference value to CAD development of other similar heat exchangers and will have a good prospect in this field.