10 results about "Heat transfer problem" patented technology

The simulation method for wall-adhering flow heat transfer of the model in the flow channel based on the STL format is provided, the method is suitable for simulation of a core disturbance structure of a light efficient heat exchanger in the aviation field, and the flow heat exchange performance of the wall-adhering insertion disturbance structure in the flow channel under the turbulence working condition can be accurately predicted. The method comprises the steps of establishing a three-dimensional model in an STL format, performing grid division on the model serving as a disturbance structure in a flow channel, and performing computational fluid mechanics simulation. According to the method, by developing a whole set of method from three-dimensional model establishment to CFD simulation, wall attachment processing of the STL format model is achieved, and the problems of flowing and heat transfer at the junction of the wall face and the disturbance structure are effectively solved. A set of method is provided for directly performing grid division on the model in the STL format, and compared with traditional operation of converting the three-dimensional model in the STL format into an entity format and performing wall surface seam reserving, the method is closer to application under the real working condition. And an effective method is provided for promoting wide-range application of the three-dimensional model in the STL format in the CFD field.

The present application relates to the technical field of nuclear reactor thermal hydraulic, in particular, to a rectangular fuel assembly coupling heat transfer coupling method and system, medium. The method or system provided by the present application mainly includes obtaining the surface heat flux density distribution of the fuel plate; performing the iteration calculation of the coolant flow distribution characteristics and the fuel plate heat conduction characteristics; judging whether the iteration calculation of the fuel plate heat conduction characteristics is completed. Through the above method, for the refined analysis and calculation requirement of the rectangular fuel assembly flow heat transfer, a detailed coupling heat transfer calculation method and process are proposed, which can be used for accurate solution of the above coupling heat transfer problem. The present application can be used as the algorithm basis for the development of the core thermal hydraulic program of the advanced research reactor (such as CARR). The calculation accuracy of the fuel assembly can be provided, so as to release the thermal design margin. It plays an important role in improving the overall performance of the research reactor.

The application discloses a double-fluid topology optimization construction method and system of a printed circuit board heat exchanger, and is characterized in that the printed circuit board heat exchanger has periodicity and symmetry in the height direction and the vertical flow direction, the full-scale model of the printed circuit board heat exchanger is known, the periodic boundary condition and the symmetric boundary condition of the printed circuit board heat exchanger are established, and a typical flow channel unit of the three-dimensional printed circuit board heat exchanger is selected to construct a three-dimensional single-flow channel model; then, according to the three-dimensional single-flow channel model, a topology optimization material representation method of a variable density method and a three-dimensional flow heat transfer control equation are coupled, a three-dimensional flow heat transfer problem is reduced to a two-dimensional design domain, and a double-fluid flow heat transfer dimension reduction model is formed; finally, according to the double-fluid flow heat transfer dimension reduction model, a variable density method topology optimization objective function and a filtering projection post-processing method are coupled to obtain the distribution of solid fins and fluid flow channels in the cold-side fluid flow channel and the hot-side fluid flow channel, that is, a double-fluid topology optimization model; the method is based on the above method to realize topology optimization with the aim of strengthening heat exchange and reducing flow resistance, to obtain the distribution of fluid fins in the design domain, to construct a new topology channel structure, and to improve the performance of the printed circuit board heat exchanger; compared with a traditional structure, the application can realize the improvement of 13.1% of the total heat exchange capacity under the condition of reducing the pump work of the heat exchanger by 38%.

The application discloses a kind of MEMS infrared light source based on heat insulation vacuum cavity and preparation method thereof, and infrared light source includes infrared light source main body and silicon cap bonded above it, and infrared light source main body includes silicon substrate, mask layer, resistance layer and insulating dielectric layer sequentially arranged from bottom to top;Resistance layer is formed by metal stripping process Graphical resistance structure;Insulating dielectric layer is annular;Resistance layer pad area is deposited with electrode layer;The upper surface of silicon substrate is etched out heat insulation groove;Silicon cap is bonded above insulating dielectric layer, and vacuum cavity is formed between silicon cap and infrared light source main body, and the inner surface of silicon cap is deposited with anti-reflection film.The infrared light source and preparation method disclosed in the application can solve the heat transfer problem of MEMS infrared light source, can effectively reduce the heat loss caused by heat convection between light source and air, improve the electro-optical conversion efficiency and thermal radiation of light source, reduce the power consumption of light source, and improve the stability in actual working environment.

The utility model relates to the field of fasteners, in particular to a connecting structure and a pot. The connecting structure comprises a plug pin assembly, a shaft sleeve assembly, a snap spring mechanism and a pot lug, the shaft sleeve assembly is provided with an axial through hole, the plug pin assembly is inserted into the axial through hole, the snap spring mechanism is arranged on the plug pin assembly in a sleeving mode, the outer wall of the snap spring mechanism abuts against the inner wall of the axial through hole, and the pot lug is arranged on the shaft sleeve assembly. The clamping spring mechanism is arranged on the shaft sleeve assembly so that the plug pin assembly and the shaft sleeve assembly can be fixed, reinforcing ribs extending in the circumferential direction are arranged on the outer wall of the clamping spring mechanism, and the pot lugs are fixedly connected with the plug pin assembly. The circumferential reinforcing ribs on the outer wall of the snap spring mechanism improve the deformation resistance and ensure that the elastic performance of the snap spring is stable in a high-temperature environment; the reinforcing ribs increase the friction force between the clamping spring and the shaft sleeve assembly, and it is ensured that the clamping spring cannot rotate accidentally in the using process; by providing stable connection and allowing the bolt assembly to be fixed at a specific angle, the heat transfer problem caused by unstable connection or random rotation is reduced.

The application provides an oil-cooled magnetic flux switching permanent magnet traction motor thermal analysis method and device, relates to the motor design technical field, and includes the following steps: determining the geometric parameters and material parameters of each component in the motor to be analyzed; abstracting and dividing each component in physics into at least one lumped thermodynamic node; determining the connection mode of each lumped thermodynamic node based on the heat transfer characteristics of each component, and establishing a parameter matrix; determining the key heat transfer parameters of the motor to be analyzed; and constructing a lumped parameter thermal network model based on the lumped thermodynamic nodes and the parameter matrix and the key heat transfer parameters. The method and device provided by the application convert the complex continuous heat transfer problem into a discrete problem for solving, have fast calculation, greatly improve the calculation efficiency, can be reanalyzed only by modifying the corresponding parameters, provide convenience for fast thermal analysis and optimization of the motor in the early design stage, and improve the thermal analysis efficiency and accuracy.

This invention designs a finite volume method for calculating the solidification heat transfer of irregular cross-section continuously cast billets. First, a 1 / 2 continuous casting billet simulation domain is constructed based on the cross-sectional dimensions of the irregular cross-section billet. An unstructured mesh is then created within this domain, and the mesh information is saved. Next, an unstructured finite volume heat transfer model is established to address the solidification heat transfer problem during continuous casting. Finally, this model is used to simulate the solidification heat transfer phenomenon of irregular continuously cast billets during the continuous casting process. The volume method is used for calculation, which improves the calculation speed compared to the finite element method. Appropriate boundary conditions are selected based on different cold zones to more accurately simulate the solidification heat transfer throughout the entire continuous casting process of irregular continuously cast billets. The method fully considers the actual situation of continuous casting of irregular billets, describes the temperature field changes during the continuous casting process, and thus provides support for the uniform cooling of irregular continuously cast billets and the improvement of their quality.

The invention discloses a compact radio frequency front end expansion layer liquid cooling heat dissipation system and a thermal control evaluation method thereof, an expansion layer of the system is arranged on an array plane frame, and an antenna and a radio frequency transmit-receive assembly are respectively connected with the expansion layer. And an array plane frame liquid cooling flow channel for cooling liquid circulation and a mounting back plate attached to the expansion layer are arranged in the array plane frame. According to the scheme, heat flow paths of the assembly end and the antenna end are creatively distinguished, heat is efficiently conducted out of the high-density winding layer and sent to the liquid cooling system to be dissipated, meanwhile, an original frame of the system is fully utilized as a main heat dissipation channel, the antenna area is subjected to heat dissipation through the integrated heat pipe, the size and weight of the system do not need to be greatly increased, and cost is reduced. The characteristics of compactness and high density of a radio frequency front end are perfectly matched; in addition, the complex three-dimensional fluid-solid coupling heat transfer problem can be simplified into a lumped parameter model easy to calculate, multi-round iteration and scheme comparison can be rapidly carried out in the design stage, the research and development period is greatly shortened, and the design success rate is guaranteed.

The application discloses an IGBT and board-level electro-thermal coupling method based on field-circuit coupling joint simulation, which comprises the following steps: establishing an IGBT joint simulation circuit model based on an IGBT circuit model, a motor model and a vector control algorithm, calculating IGBT power consumption through joint simulation of the circuit model; establishing an IGBT temperature field finite element model based on the geometric size and internal characteristics of the IGBT, calculating IGBT junction temperature through finite element simulation; using a field-circuit coupling method, realizing electro-thermal coupling of the IGBT, and solving the IGBT junction temperature; based on an IGBT main control circuit and a power circuit model, establishing an IGBT main control circuit and power circuit board-level temperature field finite element model; using a field-circuit coupling method, realizing electro-thermal coupling of the IGBT main control circuit and the power circuit board-level, and solving the board-level temperature distribution. The heat transfer problem and the electrical problem of the IGBT module and the board-level can be solved jointly, compared with the prior art, the power consumption of the IGBT module can be accurately characterized, and the junction temperature and the board-level temperature of the IGBT module can be accurately calculated, thereby improving the reliability.

The invention discloses a carbon nanotube supported catalyst and application thereof in liquid crystal polyester preparation, the catalyst comprises a carrier carbon nanotube and a carrier catalyst, the carrier is a multi-walled carbon nanotube subjected to acid treatment surface carboxylation, and the carrier is a metal salt or organic small molecule catalyst. The preparation method comprises two steps of carbon nanotube surface modification and small molecule catalyst vacuum impregnation loading. In the preparation of liquid crystal polyester, the supported catalyst is used for catalyzing acetylation reaction and subsequent melt polycondensation reaction of aromatic hydroxyl monomers; the heat stability and activity of the catalyst in a high-temperature environment are remarkably improved by anchoring the catalyst on the high-heat-conduction carbon nanotubes, the heat transfer problem of a liquid crystal state high-viscosity system is effectively solved by utilizing a heat conduction network constructed by the carbon nanotubes, the condensation polymerization reaction time is shortened, and by means of the nanometer enhancement effect of the carbon nanotubes, the high-temperature-resistant performance of the liquid crystal state high-viscosity system is improved. The tensile strength of the obtained liquid crystal polyester is synchronously improved, and the comprehensive technical effects of high efficiency, energy conservation and high quality are achieved.