8 results about "Transient heat transfer" patented technology

The application relates to the technical field of 3D printing process simulation, in particular to a 3D printing process numerical simulation method based on a near-field dynamic method, which comprises the following steps: step one, establishing a near-field dynamic transient heat transfer model; step two, establishing a near-field dynamic living and dead material point model; step three, introducing a near-field dynamic key breaking mechanism; step four, establishing a 3D printing process simulation model based on the near-field dynamic method; step five, defining basic parameters, boundary conditions and initial conditions according to 3D printing process conditions; and step six, simulating calculation and exporting results. In the application, the accumulation of materials in the 3D printing process is regarded as a change process of a scalar field, and 0-1 is used to describe the life and death states of material points in the scalar field, so that the 3D printing process can be described physically in a quite intuitive way; in combination with an explicit calculation method, the calculation amount of each time step in the numerical simulation process is greatly simplified.

The invention discloses a buried pipe group heat transfer simulation method considering hydraulic-geological boundary geometric mismatch, and belongs to the technical field of geotechnical engineering and underground energy storage. The method comprises the following steps: identifying a spatial relationship between an underground water level interface and a geological layering interface based on a geometric algorithm, executing in-layer sub-layer discretization processing, and generating a calculation sub-layer sequence with a hydraulic attribute mark; whether geometric mismatch exists or not is judged by comparing the depth of the top and bottom plates of each geological layer with the buried depth of the underground water level; constructing a composite analytic calculation model, and performing full space-time coupling solution on the transient thermal network in the borehole and the external heterogeneous moving finite line source field; and outputting a long-term thermal response prediction result, and performing optimization evaluation on the buried pipe system layout based on prediction data. According to the method, the complex boundary condition that the underground water level line does not coincide with the geological stratified interface is accurately described, and full coupling calculation of transient heat transfer in the pipe and stratified non-uniform convection-diffusion heat transfer outside the pipe is achieved.

This invention relates to the field of heat flux technology and provides a novel wall heat flux partitioning model based on bubble merging behavior and the evaporation region. Spatially, the model divides the wall into a non-bubble-affected region, a nucleation point region, a bubble sliding region, and an evaporation region. Temporally, it divides the bubble nucleation cycle into bubble waiting time and bubble generation time, and the bubble sliding cycle into transient heat transfer-dominated time and one-way convective heat transfer-dominated time. Based on this spatiotemporal partitioning, the total wall heat flux is composed of quenching heat transfer caused by bubbles leaving the nucleation point, transient heat transfer caused by sliding bubbles, evaporation heat transfer during bubble growth, one-way convective heat transfer in the non-bubble-affected region, and steam heat transfer in the evaporation region. The total wall heat flux is expressed as: [Formula omitted for brevity]. This model can accurately predict the wall heat flux during the nucleation boiling stage and successfully predict the occurrence of the critical heat flux density.

The application relates to a method and device for intelligent hole-forming design of a medium-deep buried pipe and electronic equipment, wherein the method comprises the following steps: collecting a measured mud inflow temperature and a measured return mud temperature of a target medium-deep buried pipe in a construction drilling process; determining a hypothetical drilling depth according to an actual engineering progress, and generating underground soil temperature distribution information; obtaining a predicted return mud temperature based on a pre-constructed two-dimensional transient heat transfer numerical model of a drilling process column coordinate, calculating an absolute deviation value, correcting the underground soil temperature distribution, and reconstructing a geothermal field until the absolute deviation value is smaller than a preset deviation threshold; calculating a heat extraction amount of the buried pipe based on a pre-constructed buried pipe heat transfer numerical model and the geothermal field, adjusting the hypothetical drilling depth, and determining the depth and quantity of the buried pipe until the heat extraction amount exceeds a preset design value. Thus, the problems of drilling depth redundancy or deficiency, high construction cost, significant geothermal field prediction deviation and the like caused by systematic errors in depth setting in the related art are solved.

This application provides a 3D modeling method and system for manufacturing liquefied natural gas (LNG) ship pipe fittings. The method assigns material properties to each component of the 3D geometric model of a double-walled LNG ship pipe. Then, in the 3D modeling environment, a transient heat transfer-thermoelasticity bidirectional coupling analysis is performed to obtain time-series data of the normal relative displacement of the inner and outer pipes. Based on this time-series data, an effective gap dynamic distribution field is determined. The gap value at each moment in the effective gap dynamic distribution field is compared with a preset allowable compression margin threshold for the insulation layer to form a set of potential insulation failure risk points. Using this set of potential insulation failure risk points as constraints, the geometric dimensions or axial spacing of the support blocks in the region containing the potential insulation failure risk points are automatically adjusted to generate an optimized 3D model of the double-walled pipe. Using this solution, the transient insulation failure risk of the double-walled pipe during the entire cooling process can be eliminated during the 3D modeling stage.

The method for predicting the temperature field of a fire-corroded beam based on a physical information neural network belongs to the field of post-fire structural temperature field analysis technology. It includes the following steps: (1) constructing a heat transfer model; (2) constructing a simplified rust expansion cracking model; (3) constructing a physical information neural network model; (4) training and evaluating the network; and (5) detecting the temperature field of the fire-corroded beam section using the physical information neural network model. This invention improves local prediction accuracy by introducing an adaptive importance sampling and interface focusing training strategy to dynamically densify sampling points in rust expansion cracks and high-temperature gradient regions. Simultaneously, it embeds control equations, latent heat of phase change, and complex boundary conditions into the model to achieve transient heat transfer modeling under the coupled effects of fire and water spray cooling. By enhancing the physical consistency of different material interfaces through heat flow continuity constraints, it significantly improves the accuracy and stability of temperature field prediction under complex working conditions while ensuring computational efficiency.

This invention relates to the field of performance simulation and evaluation technology, specifically to a comprehensive performance evaluation method for cryogenic liquid hydrogen ball valves based on an adaptive working condition algorithm. The method includes the following steps: constructing a simulation model, calculating the mesh wetting fraction to generate the fluid-solid wetting state, and outputting the weighted heat flux; inputting the heat flux into heat transfer calculations and fusing hardening parameters to calculate the microscopic peak-valley transient stiffness; combining contact pressure to generate distorted coordinates and constructing nodal plastic deformation; analyzing deformation parameters to extract extreme values, calculating damage contributions, performing fatigue deduction, and constructing a comprehensive evaluation. In this invention, by combining nucleus and film heat transfer mechanisms to deduce energy distribution and restore transient heat transfer boundaries, fusing normal temperature difference to correct the initial modulus, characterizing the cold brittle degradation law of cryogenic materials, relying on microscopic stiffness to analyze pressure mapping distortion to obtain nodal plastic deformation, calculating single-step damage contributions, and performing fatigue evolution analysis to effectively eliminate static mechanical model errors, thus achieving accurate prediction of ball valve performance.

The application discloses a cleaning degree detection method and device suitable for long-distance refrigeration pipelines, relates to the related technical field of cleaning degree detection, and comprises the following steps: determining the injection gas type and injection pulse signal of the long-distance pipeline to be detected; connecting a liquid nitrogen vaporization device, controlling a pulse injection valve to inject gas into an inlet through the injection pulse signal, collecting the temperature of the outer surface by using an infrared thermal imaging array, and outputting real-time response data of the outer surface temperature; constructing a heat transfer abnormal area identification model through a three-dimensional transient heat transfer equation of the pipeline and marking the abnormal area to obtain the heat transfer abnormal area; and analyzing the heat transfer abnormal response data of the heat transfer abnormal area to generate a cleaning degree detection result. The technical problems that the long-distance refrigeration pipeline cleaning degree detection efficiency is low, real-time dynamic monitoring cannot be realized, and local pollution areas are difficult to accurately identify in the prior art are solved, and the technical effects of accurately positioning the heat transfer abnormal area and efficiently and accurately detecting the cleaning degree of the pipeline are achieved.