Numerical Investigation Of A Novel Manifold Micro-pin-fin Heat Transfer Structure Combing Chessboard Nozzle-jet Concept For Ultra-high Heat Flux Removal

With the rapid development of science and technology,the problem of heat transfer has gradually become an important factor which restricts the further development of the science and technology and the economy.The micro heat transfer structure,as a highly potential and efficient cooling technology,is a major direction to solve the problem of high heat flux density of heat transfer.Based on the micro-channel heat sink structure,a novel heat sink combining the manifold flow distributor,impinging nozzle-jet,and micro-pin-fin concepts is proposed.The design is inspired by the structure of the chessboard and taking the distribution characteristics of manifold system into account to solve the problem of large pressure drop of micro pin-fin.The micro-pin-fin heat sink structure and effect of nozzle impingement jet flow could enhance the heat transfer,and the manifold system could help to promote the uniform of flow distribution.Therefore,the novel combined heat sink structure could retain the original high heat transfer efficiency and also effectively reduce the pressure drop of the heat sink.Since the basic heat transfer structure in the hybrid receiver is periodical and symmetrical,we extract a three-dimensional unit cell of heat transfer structure.The heat transfer fluid used in the simulation is deionized water.The influence of the three independent geometrical parameters,WPF,WN,and HPF and the multiple pin-fin structure on the hydrodynamic and thermal performance of the unit cell is studied by numerical simulation.Finite volume method is employed in ANSYS FLUENT to solve the governing equations and boundary conditions.The results show that,for an 1 × 1 cm2 chip(or PV cell),a total thermal resistance of 0.094 ×10-6 m2K/W is achieved at a flow rate of 0.2 L/min and a pressure drop of 4255 Pa.The maximum cooling capacity of 750 W/cm2 is available when the temperature difference between fluid inlet and chip is 24 K.In addition,we also studied the posibility of the novel heat transfer structure applied into solar receiver.A numerical model of the unit cell is established to simulated to the receiver performance.Results show that,when the air volumetric flow rate of the solar receiver is ranging from 10.8 to 32.4 L/min,and the solar energy flux is ranging from 200,000 to 600,000 W/m2,the pressure drop is ranging from 233.9 to 6289.0 Pa,the highest surface efficiency is evaluated to be 92.12%,and the highest global heat transfer efficient achieves 1180 W/(m2·K).