Research On Heat Transfer Enhancement Mechanism And Heat Transfer Characteristic Of Compound Corrugation Plate Heat Exchanger

As a thermal power mechanical apparatus, plate heat exchangers have been widely used in the fields of energy transport processes for its perfect performance. The deeper researches on plate heat exchanger are necessary for enlarging its range of application. On the base of analyzing physical mechanism of convection heat transfer, a novel net-stream plate heat exchanger with compound corrugation was proposed, and heat transfer and flow resistance characteristics of which were investigated through numerical and experimental methods in this thesis. The conclusions of investigations can be as governing principles for plate heat exchanger's optimum design and thory basis of thermal and hydraulic calculating.The phsical mechanism of convection heat transfer between single phase fluid and rigid wall were analyzed. A viewpoint that the component normal to wall of fluid velocity is the key factor influencing on convection heat transfer was proposed, and according to which a method of heat transfer enhancement was proposed that enlarge the region of flow velocity lies at a larger angle with wall in flow field. Heat exchange between single phase fluid and rigid wall might be regarded as the result of mass exchange of fluid with different temperature between near wall and mainstream, and the fluid motion normal to wall acts a major part in enhancing the exchange. When fluid's velocity lies at a larger angle with wall, the component normal to wall of fluid velocity is greater certainly, so enlarging the region of flow velocity lies at a larger angle with wall in flow field, the heat transfer between wall and fluid will be enhanced.Based on relevant researches reported by literature and numerical simulation results carried out in this thesis, a conclusion was drawn: the flow channel formed by 'non-Parallel curved surface' can induce fluid flowing at a larger angle with wall. The flow channels of plate heat exchanger are all formed by 'non-Parallel curved surface', so it has better perfect performance than other type of heat exchangers.By numerical simulation to flow field in traditional cross-corrugated plate heat exchangers, firt from view of the inclination angle β would influence the component of momentum in direction of corrugation, the prime reason that affects flow pattern between two corrugated plates and heat was enhanced has been interpreted.Through numerical studys in this thesis, a fact that the corrugation's geometry parameters can markedly influence the performance of traditional cross-corrugated plate heat exchangers has been found, and the law of geometry parameters influence the...