Design And Development Of Exhaust With Vapor Condensation Heat Recovery Unit CAD System

Vapor condensation is an important topic in chemical,energy and power fields.Many experts have done much research in it, however many work is limited to pureworking fluid problem, and waste heat recovery of exhaust with vapor condensation isnumerous in industrial fields. As far as existing literatures and design handbooks areconcerned, the design method and standard of heat exchanger have been relativelyperfect, but not for this special exhaust with vapor condensation heat recovery unit, itsheat transfer process supported by various content such as two-phase flow,heat andmass transfer,latent and apparent heat exchange, so design calculation process ofheat recovery unit is complex and tedious, together with the condition and structure isvarious different, bringing more heavier design workload. The traditional manualcomputation and drawing could hardly meet the user need and market developmentbecause of its long design period and poor reliability. Therefore, the heat recovery unitCAD system which can realize the functions of technological design calculation andCAD parametric drawing has important engineering application value basing on aalgorithm which is suitable for exhaust with vapor condensation heat recovery unit.In this paper, By analysing the condensation heat transfer mechanism of vapormixture with non-condensable gas and device structure and using the object-oriented,modular and structured concepts, the design software system which can realize theautomatic calculation,parametric drawing,modification and output was developed forexhaust with vapor condensation heat recovery unit. Major research results are asfollows：(1) Based on comprehensive consideration of the condensation heat transfermechanism of vapor mixture with non-condensable gas and engineering practice, anew algorithm was established. For details, please refer to chapter4of this paper.(2) Based on the object-oriented,modular and structured concepts, the overalldesign scheme of CAD system for heat recovery unit including process designcalculation subsystem,parametric drawing subsystem and results export subsystemwas brought forward.(3) Based on heat and mass transfer mechanism of exhaust with vaporcondensation heat recovery unit,the process design calculation subsystem wasdeveloped, which could realize the automatic calculation of thermal parameters andresistance parameters of six different structure heat exchangers in combination with production practice. In view of the heat transfer process with vapor condensation,infinitesimal method (segmentation method)for calculation process of heat recoveryunit was used.(4) Using modular method and taking AutoCAD as Second-development Platformbased on VB6.0, the parametric drawing subsystem was achieved, which could carryout the drawing of tube sheet and heat exchange section automatically.(5) Taking single tube and double shell heat recovery unit as an example, thefunctional characteristics and using process of software were introduced at the end ofthis paper. With friendly interface, easy operation and strong practicability, thissystem has been used in Zheng Da Qing Ke Hi-Tech Machinery Co., Ltd. By testing,this system run well and results is accurate and reasonable. The running resultsindicate that the system could improve the design efficiency and quality of heatrecovery unit and help company make fast response to the customer requirement inorder to obtain an early start in the market, there are lots of practicality value.