Finite Element Analysis And Experimental Investigation About The Structure And Heat Transfer Of Detachable Spiral Heat Exchanger

As a typical compact heat exchanger, although detachable spiral heat exchanger (hereinafter referred to as DSHE) has many advantages: simple structure, convenient manufacturing, high thermal efficiency, low drag ,easy cleaning, etc, its application and dissemination is not satifactory because of the lack of systematic design theory. In this paper, some key problems arising during the design process of DSHE was researched and the special method for calculating important design parameters was also given. In addition, the theoretic model , finite element analysis and experiment test was done to the circular-shaped cover with a concentric ring and topsy-turvy cone, the distribution of flow, pressure and temperature of fluid without phase transition in spiral duct was simulated , and a set of CAD software system for the design and check of DSHE was developed.In accordance with the basic structure, features and applications of DSHE, several general geometric calculation equations for the DSHE with uneven spiral ducts is deduced and the some parameters about structure and flow of DSHE were also optimized in this paper.The theoretical mechanical modol of circular-shaped cover with a concentric ring and topsy-turvy cone was built on the basis of classical theory of plates and shells and its distributions of deformation and stress were also analyzed with the help of finite element method. At the same time, the influence from the location, height and thinckness of topsy-turvy cone and concentric ring on the maximum deformation of circular-shaped cover were researched. The results computed by theoretical mechanical modol and finite element method conformed well to practical datas and can satisfy accuracy request of engineering calculation,which proved the correctness of theoretical mechanical model.Based on the mathematical model about flow and heat transfer of DSHE, the distribution of flow, pressure and temperature of fluid without phase transition in spiral duct was simulated. In addition, the influences of flow rate, flow direction, flowage and structural parameters such as the height of heat exchanger and the spacing of flow duct on the heat transfer performance were discussed in this paper, which have good theory guidance and reference value to the optimum design and parameter testing.Furthermore, with the Object-Oriented programming theory, the computer aided design (CAD) software of DSHE was developed in Visual C++ 6.0 environment, which consists of three function parts of design, testing and plotting and can complete basic heating calculation, the simuluation of temperature distribution and the testing of strength, stiffness and stability. The actual service proves that this CAD software about DSHE is convenient, effective and reliable.