Performance Analysis And Optimization Of The Regular Hexagonal Plate Heat Exchanger With Spherical Ribs

Plate heat exchangers(PHE) are more and more widely used in petroleum, chemical, light industry, metallurgy, power and other engineering fields with its advantages like compact structure, excellent performance, ease to clean, etc. It plays an important role in improving energy and economic efficiency of the whole national economy and industrial production. Therefore, it has important practical significance and applied value to design and optimize new PHE for improving the overall performance.In this paper, we investigate a novel PHE, Regular Hexagonal PHE with Spherical Ribs(RHPHE) by using numerical method, followed with the optimal parameter design through the analysis of its internal heat transfer and pressure drop characteristic, Which is specifically shown as follow:First, the physical meaning and the application in heat exchanger of three heat exchanger evaluation criteria, JF Factor, Entropy Minimization Method, and Entransy Dissipation Principle, are compared. JF Factor was found to be an appropriate criterion foras the First Law of Thermadynamics-based performance evaluation. In the context of the Second Law of Thermadynamics, Entransy Dissipation Principle avoided the contradictions and problems in practical application of Entropy Minimization Method. Then, we extend it to the actual PHE numerical calculation.Considering various influencing factors, we have established the PHE numerical model, and tested RHPHE in an experimental installation for experimenta verification. The experimental results fit well with the numerical results, which means the numerical model is reliable and can accurately predict the heat transfer and flow in RHPHE.Then, we use the verified model to study the heat transfer and pressure drop properties of RHPHE. Based on the obtained fluid flow and temperature, pressure, entransy distribution under different conditions, the effect of structure on entransy dissipation number is investigated. Results showed that the entransy dissipation number is not suitable as a separate heat exchanger evaluation criterion because of ignorance of the flow resistance. Compared with a traditional chevron PHE, RHPHE has a better overall performance.Finally, optimized design is carried on by chosing curvature and scale factor of spherical ribs as structural parameters. Effects of different structural parameters on heat tansfer performance, resistance performance, and entransy dissipation number distribution are studied. It is found that the optimal direction of the Entransy Dissipition Principle is to minimize the temperature gradient. So it's not suitable for designing new plate type. Therefore, using JF Factor as main optimization objective, and Entransy Dissipation Number as auxiliary optimization objective, the optimal structural design and operating parameter of RHPHE are obtained.