8 results about "Line heat source" patented technology

The invention discloses a multi-heat-source digital twin model automatic optimization and decoupling control method and system, and the method comprises the steps: constructing a local two-dimensional plane coordinate system, obtaining the end point coordinates of heat sources, and calculating the heat radiation intensity of the heat sources to a target point; establishing a geometric parameter model of the additive manufacturing multi-heat-source system, and establishing a radiation field response model of the multi-heat-source system based on a linear superposition principle; according to the heating requirement of additive manufacturing, a target heat radiation field is designed, optimal power distribution of the target heat radiation field is calculated, and optimal heat source structure parameters are determined based on geometric constraints of a physical basis; and according to the optimal heat source structure parameters, a decoupling control rule is designed, and heat source power is adjusted according to feedback data to compensate deviation. According to the method, the point heat source, the line heat source and the plane heat source are abstracted into the line heat source in a unified mode, a universal frame is provided for digital modeling of a complex multi-heat-source system, and the complexity of modeling for different heat source types is avoided.

The invention discloses an internal meshing powerful gear honing tooth surface temperature field calculation method based on a superposition point heat source, and belongs to the technical field of gear machining and manufacturing. Comprising the steps of constructing a tooth surface equation and a honing machining coordinate system, calculating a relative speed vector between a gear and a honing wheel in the honing machining process, determining a tooth surface contact point based on the meshing principle according to the relative speed vector between the gear and the honing wheel, calculating the heat flux density at the tooth surface contact point, and obtaining a continuous tooth surface contact line heat source based on the heat flux density. On the basis of the point heat source superposition principle, contact point heat sources of the whole tooth surface are superposed, and the temperature rise generated by the whole tooth surface to a target point in the honing machining process is calculated. According to the method, the dynamic gear honing machining process is accurately simulated, the problem that a traditional temperature field method is not applicable is solved, through high-precision calculation, gear surface burning can be effectively prevented, the technology is optimized, residual stress is predicted, a key tool is provided for improving gear quality, and the method is efficient in calculation and convenient for engineering application.

This invention discloses a four-step inversion method for thermal properties based on analytical models and unsteady-state numerical models, comprising the following steps: 1) Using water temperature observation data after the 10th hour of the thermal response test, the thermal conductivity of the soil and rock is calculated using the linear slope method based on a linear heat source analytical model; 2) Using water temperature observation data after the 10th hour of the thermal response test and the obtained thermal conductivity of the soil and rock, assuming the thermal conductivity and volumetric specific heat of the backfill material in the borehole, the volumetric specific heat of the soil and rock is inverted based on a one-dimensional unsteady-state numerical model in the entire space; 3) Using water temperature observation data from the first two hours of the thermal response test, the obtained thermal conductivity and volumetric specific heat of the soil and rock, the thermal conductivity and volumetric specific heat of the backfill material in the borehole are simultaneously inverted based on a one-dimensional unsteady-state numerical model in the entire space; 4) Using water temperature observation data after the 10th hour of the thermal response test, the thermal conductivity of the soil and rock, the thermal conductivity and volumetric specific heat of the backfill material are obtained, and the volumetric specific heat of the soil and rock is inverted based on a one-dimensional unsteady-state numerical model in the entire space.

The present application relates to the technical field of rail transit contact rail state monitoring and fault early warning, and particularly relates to a contact rail temperature rise infrared online monitoring method and system, which comprises the following steps: firstly, mapping pixels to mileage and collecting multi-band long-wave infrared data, synchronously obtaining traction working conditions and applying phase-locked thermal excitation to generate infrared observation data in the mileage domain; then, correcting system response, calibrating radiation, and implementing phase-sensitive demodulation, and inversely obtaining an absolute temperature field according to a multi-band radiation transmission model; further inversely obtaining an equivalent line heat source according to a heat conduction equation, constructing an expected temperature rise baseline, and generating an alarm object containing a position interval and intensity by combining a generalized likelihood ratio with spatial continuity; finally, returning phase-locked and imaging parameters according to sensitivity and Fisher information. The present application realizes quantitative, locatable, low false alarm temperature rise early warning and adaptive observation.

The application provides a control method of a medium-deep geothermal well heat extraction system and related equipment, space temperature distribution data of a target geothermal well from a well mouth to a well bottom, actual circulation flow data and electric meter energy consumption data are acquired; the space temperature distribution data, the actual circulation flow data and the electric meter energy consumption data are solved based on an extended finite-length line heat source digital twin model and a self-adaptive fuzzy PID control algorithm, control instructions of a circulating water pump and a heat pump unit in the medium-deep geothermal well heat extraction system are obtained, and the problems that a current geothermal well control system cannot perceive a real heat state underground, control is lagged and a heat fault underground cannot be accurately positioned are solved.

The invention belongs to the field of measurement and control, and provides a stress-controllable near-phase-change-region frozen soil heat conductivity coefficient measuring device and method.The stress-controllable near-phase-change-region frozen soil heat conductivity coefficient measuring device comprises a closed pressure chamber, a stress loading unit, a deformation real-time monitoring unit, an unfrozen water content monitoring unit and a heat conduction measuring unit; a stress loading unit is arranged outside the closed pressure chamber, a deformation real-time monitoring unit, a heat conduction measuring unit and an unfrozen water content monitoring unit are arranged on the closed pressure chamber, and the deformation real-time monitoring unit, the unfrozen water content monitoring unit and the heat conduction measuring unit are all connected with a data processing system. Calculating void ratio change and phase change latent heat respectively according to axial deformation and unfrozen water content change of the to-be-tested sample, and correcting and calculating the heat conductivity coefficient based on a linear heat source model by combining temperature change. The stress is controllable, melting latent heat caused by heating of the thermal probe is accurately considered, and the method has scientific and practical significance in testing of the frozen soil in the near-phase-change region in a real stress state.

The invention discloses a large-scale long-period cross-seasonal buried pipe heat accumulator temperature distribution and heat accumulation amount calculation method. The model is based on a quasi-three-dimensional and finite long-line heat source model, and the outlet temperature of a buried pipe, the average temperature of a heat accumulator, the heat accumulation amount of the heat accumulator and temperature distribution are calculated according to the material physical property, the inlet temperature of the buried pipe and the flow velocity. According to the model, firstly, the outlet temperature is calculated through a quasi-three-dimensional model in a drill hole according to the initial temperature and the inlet temperature of a heat accumulator, so that the heat flow of each buried pipe is calculated, and the average temperature and the heat storage capacity of the heat accumulator are calculated through an equivalent single-pipe method according to the obtained heat flow; and the obtained heat flow is transmitted to a finite long-line heat source model outside the drill hole to solve temperature distribution, and then is transmitted to the next cycle for calculation according to the obtained temperature distribution. According to the method, based on the quasi-three-dimensional model and the finite long-line heat source model, the engineering algorithm, the fast Fourier algorithm and the two-dimensional discrete convolution acceleration are used for solving the temperature of the heat accumulator, and the problem that the calculation amount of a traditional model is large is solved.

The invention relates to the technical field of track traffic contact rail state monitoring and fault early warning, in particular to a contact rail temperature rise infrared online monitoring method and system.The method comprises the steps that firstly, pixel-to-mileage mapping is established, multi-band long-wave infrared data are collected, a traction working condition is synchronously obtained, phase-locked thermal excitation is applied, and the traction working condition is determined; generating mileage domain infrared observation data; then system response correction and radiation calibration are carried out, phase-sensitive demodulation is carried out, and an absolute temperature field is obtained through joint inversion according to a multi-band radiation transmission model; further inverting an equivalent line heat source according to a heat conduction equation, constructing an expected temperature rise base line, and generating an alarm object containing a position interval and intensity by combining a generalized likelihood ratio with spatial continuity; and finally, phase locking and imaging parameters are transmitted back according to the sensitivity and Fisher information. According to the invention, quantitative, localizable and low-false-alarm temperature rise early warning and adaptive observation are realized.