21 results about "Heat transfer problem" patented technology

A multi-fidelity topological optimization method, system, device and medium for a microchannel flow boiling process, and the method comprises the steps: firstly carrying out low-fidelity topological optimization on a single-phase laminar flow convective heat transfer process to generate a group of candidate topological optimization structures; then calculating the speed, temperature and two-phase distribution in a single-phase heat transfer process and a flow boiling heat transfer process on the basis of a high-fidelity flow boiling numerical model, and constructing a novel objective function capable of reflecting flow boiling heat transfer characteristics on the basis of leading factors of the flow boiling heat transfer problem in the microchannel; and finally, directly generating a topological optimization structure under a low-fidelity condition based on the new objective function. Aiming at the defect that an existing topological optimization algorithm cannot directly optimize the flow boiling heat transfer problem, rapid and accurate multi-fidelity topological optimization is realized by constructing a novel objective function capable of reflecting the flow boiling heat transfer characteristics; according to the designed topological optimization structure, local hot spots are eliminated, thermal resistance is reduced, and temperature uniformity is improved.

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 invention discloses a fluid-solid coupling heat transfer simulation method and device based on a compressible ghost point immersion boundary method and a medium. The method comprises the following steps: acquiring a flow field and a solid temperature field in the (st-1) th step; obtaining the position and the speed of the mass center of the solid and the angular speed of the solid in the (st-1) th step; determining the attributes of grid nodes; if a new fluid node exists, calculating a fluid variable value at the new fluid node; calculating a solid centroid acceleration, a solid angular acceleration and a solid speed at a grid node in the solid; calculating a flow field ghost point variable value; if a new solid node appears, calculating the temperature value of the solid at the new solid node; calculating a solid temperature ghost point value; updating a solid temperature field and a flow field; and when the simulation step number is reached, ending the whole simulation process. The fluid-solid coupling heat transfer simulation method based on the compressible ghost point immersion boundary method is suitable for solving the problem of coupling heat transfer between a static or moving object and a compressible flow.

The invention discloses a high-order model control method based on a linearization model and GA-ADRC, and relates to the field of heat exchanger control simulation, and the method comprises the steps: constructing a single-shell-pass single-tube-pass heat exchanger model which comprises a shell and a heat exchange space, the heat exchange space is divided into a shell pass region and a tube pass region, and the shell pass region is internally provided with a plurality of baffle plates; carrying out heat balance analysis to obtain a dynamic equation of each heat exchange link of the heat exchanger, carrying out discretization processing, and carrying out linearization processing on the mass flow rate and the temperature of the shell pass hot fluid to realize decoupling; and an ESO state observer is arranged to estimate the state variable of the heat exchanger in real time, and the single-shell-side and single-tube-side heat exchanger model is controlled through a GA-ADRC-based nonlinear model control method. According to the method, the complex heat transfer problem can be linearized, a GA-ADRC controller independent of an accurate model is designed, the actual nonlinear model can be successfully adapted, the adjustment time is shortened, and the control precision and the anti-interference capability are effectively improved.

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 invention belongs to the technical field of energy conservation in the iron and steel industry, and particularly relates to a system and method for improving heat exchange of an internal combustion hot blast stove through flue gas reuse. Comprising hot-blast stoves, smoke exhaust branch pipes, a smoke exhaust header pipe and a chimney, hot air pipelines of the hot-blast stoves are connected with blast furnaces, each hot-blast stove is connected with the smoke exhaust header pipe through the corresponding smoke exhaust branch pipe, and the smoke exhaust header pipe is connected with the chimney; a regulating valve and a check valve are arranged on the smoke exhaust branch pipe, a smoke recycling pipeline is led out between the regulating valve and the check valve, the smoke recycling pipeline is connected into the hot-blast stove, the connecting position is above the gas pipeline and the combustion-supporting air pipeline, and the smoke recycling pipeline is bent upwards to be the same as the flame direction after being connected into the hot-blast stove. The check valve is close to one side of the smoke exhaust header pipe. The problem that convective heat transfer of checker bricks of the hot blast stove is weakened due to reduction of the smoke amount in the arch crown heat preservation and heating stage of the internal combustion type hot blast stove is solved through smoke recycling, and the hot air temperature can be effectively increased by 5 DEG C or above.

The present invention relates to a method for topological optimization design of a dual-fluid heat exchanger structure based on a multi-material model, comprising: defining a topological optimization design domain and design variables of the heat exchanger including the flow areas of the hot and cold fluids; establishing an objective function and setting constraints, with the optimization objectives of maximizing the heat transfer within the design domain and minimizing the inlet and outlet pressure drops, and constructing a topological optimization model; solving the governing equations for the flow problems of the cold and hot fluids respectively, solving the corresponding topological optimization models, and obtaining the corresponding velocity fields; solving the heat transfer problem using the heat conduction equation based on the combined velocity field obtained by superimposing the two velocity fields; performing a sensitivity analysis based on the solution to the heat transfer problem, and updating the design variables using a topological optimization algorithm based on the results of the sensitivity analysis; and iterating and updating the design variables multiple times until the objective function converges and meets the predetermined design requirements. The present invention efficiently solves the problem of heat exchanger structure optimization in different scenarios.

The application discloses an SCR system conjugate heat transfer calculation method based on OpenFOAM secondary development, and the secondary development is carried out based on an open source CFD library OpenFOAM; a temperature solving method of a solid field is implanted on the basis of an original fluid field solving method, so as to solve the problem that a solver for the flow field conjugate heat transfer characteristics of a diesel engine aftertreatment system has not been developed maturely in the prior art. On the basis of the gas field solver of the computational fluid dynamics open source library OpenFOAM, the heat conduction calculation method of the solid field is implanted, the numerical calculation of the diesel engine exhaust aftertreatment SCR system conjugate heat transfer problem is realized, and the application range is effectively widened.

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 invention discloses a simulation method and system for wind flow heat transfer of a high-ground-temperature tunnel. The method comprises the following steps: constructing a tunnel geometric model containing different heat insulation structures by utilizing drawing software; importing the tunnel geometric model into numerical simulation software, constructing entity units in the numerical simulation software, and dividing grids; initial conditions and boundary conditions are set, numerical simulation is conducted through a finite difference method, and the air flow heat transfer processes in different construction stages and under the heat insulation structure are simulated; and analyzing a numerical simulation result, generating a distribution cloud picture of a temperature field, comparing heat transfer effects of different construction stages and the heat insulation structure, and determining an optimal design scheme. According to the method, the wind flow heat transfer problem in the high-ground-temperature tunnel is systematically solved through tunnel geometric model building, parameter setting, numerical simulation and result analysis, scientific basis and actual guidance are provided for tunnel engineering by simulating different heat insulation structures and the heat transfer process of the construction stage, and the safety and efficiency of the engineering are improved.

The invention relates to the technical field of battery monomer shells, in particular to a heat insulation shell of an energy storage battery monomer and a preparation method of the heat insulation shell. The method comprises the steps that a shell of an energy storage battery monomer is subjected to surface cleaning treatment, the treated shell serves as an anode workpiece to be placed in electrolyte of an electrolysis device, voltage is applied between the anode workpiece and a cathode, and the applied voltage is constant voltage or stepping voltage; the surface of the thermal insulation shell is provided with a porous membrane structure, the out-of-plane heat conductivity coefficient of the thermal insulation shell is lower than 125 W / (m.K), and the thermal insulation shell has thermal insulation performance and can solve the problem of heat transfer between monomers caused by battery thermal runaway.

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 invention belongs to the technical field of energy conservation in the iron and steel industry, and particularly relates to a system and method for improving heat exchange of a hot-blast stove by adjusting smoke distribution. Comprising hot blast stoves, smoke exhaust branch pipes, a smoke exhaust header pipe and a chimney, hot air pipelines of the hot blast stoves are connected with blast furnaces, each hot blast stove is connected with the smoke exhaust header pipe through the corresponding smoke exhaust branch pipe, the smoke exhaust header pipe is further connected with the chimney, and the smoke exhaust branch pipes are provided with adjusting valves and check valves. A smoke recycling pipeline is led out between the adjusting valve and the check valve to be connected to the vault of the hot blast stove and inclines downwards at the angle of 20-30 degrees with the horizontal plane, and the check valve is close to one side of the smoke exhaust header pipe. The problem of weakening of convective heat transfer of checker bricks of the hot blast stove caused by reduction of the flue gas amount in the vault heat preservation and heating stage of the internal combustion type hot blast stove is solved by adjusting the flue gas distribution state through flue gas recycling, and the hot air temperature can be effectively increased by 5 DEG C or above.

The invention provides a bridge main cable equivalent temperature calculation method and system based on a simplified heat conduction model, and the method comprises the steps: inputting the midpoint temperature of each side of a regular polygon cross section of a main cable before cable tightening in a construction period as a simplified boundary condition, directly taking the midpoint temperature as a boundary, simplifying a heat transfer problem, and building a one-dimensional straight rod heat transfer model; a corresponding heat conduction partial differential equation is further established and solved, an analytical calculation formula between the weighted average temperature and the equivalent temperature of the cross section of the main cable is derived, and the function of solving the equivalent temperature of the main cable of the suspension bridge is achieved. According to the method, the boundary temperature, the material parameters and the geometric dimension are incorporated into a unified calculation framework, the calculation complexity is reduced, the calculation efficiency is greatly improved, and the formula is not only suitable for the main cable before cable tightening, but also suitable for the main cable with the circular cross section after cable tightening through finite element analysis verification. And an efficient and reliable technical support is provided for real-time analysis of the temperature effect of the main cable in bridge construction monitoring and a health monitoring system.

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.

The utility model belongs to chemical machinery technical field discloses an epoxy resin waterproof composite material reactor, including base and fixedly connected on the base reactor body, the top and bottom of reactor body are opened with feed inlet and discharge gate respectively, the top of reactor body is provided with the cover plate of lift movement, is connected with the rotary rod that rotates on the cover plate, a plurality of stirring rods are fixedly connected on the rotary rod, the top of rotary rod is fixedly connected with first electric push rod, the stretch -out end of first electric push rod is fixedly connected with the scraper ring, the utility model discloses the setting of the scraper ring that first electric push rod drive moves along the reactor inner wall axial, realizes dynamic removal inner wall adhering material while stirring operation, eliminates the volume loss and the uneven heat transfer problem of traditional equipment because raw material hangs wall, makes the cleaning operation of subsequent reactor more convenient.