22 results about "Inlet velocity" patented technology

The invention provides a diffuser inlet speed distribution simulation device and full-ring combustion chamber test equipment. The diffuser inlet speed distribution simulation device comprises a current limiting ring; the flow limiting ring is provided with a plurality of openings evenly distributed in the circumferential direction of the flow limiting ring. The opening is symmetrical relative to the radial direction of the flow limiting ring, and on the section perpendicular to the axial direction of the flow limiting ring, the opening is provided with an opening outer edge, an opening inner edge and two opening side edges connected with the opening outer edge and the opening inner edge; the outer edge of the opening is a straight line perpendicular to the radial direction of the flow limiting ring or an arc line with the center of the flow limiting ring as the center, and the distance between the two end points of the outer edge of the opening in the circumferential direction of the flow limiting ring is a first distance a. The inner edge of the opening is a straight line perpendicular to the radial direction of the flow limiting ring or an arc line with the center of the flow limiting ring as the center, and the distance between the two end points of the inner edge of the opening in the circumferential direction of the flow limiting ring is a second distance b. The maximum distance between the edges of the two opening sides in the direction perpendicular to the radial direction of the flow limiting ring is a third distance c; and cgt; a, and cgt; b.

The invention discloses a method for analyzing lubricating oil recovery efficiency in an aero-engine hot-end bearing cavity oil return process, and belongs to the field of aero-engine bearing cavity structure system design. The method comprises the steps that the rotating speed and the pressure change range of a bearing cavity are determined according to the flight envelope of an aircraft; and for each rotating speed and pressure state point, an oil return coefficient, an invalid oil return ratio, an oil return pipe inlet speed parameter and a stability characterization parameter thereof are obtained through simulation analysis. And through dimensionless processing and reasonable weighting, comprehensive efficiency parameters of the oil return efficiency of the bearing cavity under the rotating speed and the pressure are obtained, so that quantitative characterization of the oil return efficiency under a single working condition is realized. Furthermore, in the rotating speed and pressure change range of the bearing cavity, weighted average is carried out on the comprehensive efficiency parameters of the multiple key state points, and comprehensive parameters used for evaluating the oil return efficiency of the bearing cavity in the whole flight envelope are obtained. According to the invention, guidance can be provided for optimal design of a bearing cavity oil return structure, and a bearing system is supported to realize high reliability.

The invention provides a high-precision tandem cold mill second flow thickness control method which comprises the following steps: firstly, integrating an inlet / outlet second flow difference to correct a strip steel inlet speed, and pre-calculating a strip steel outlet thickness difference by using a second flow equation; compensating the speed difference between the inlet tension roller and the first rack, and correcting the second flow pre-calculation thickness difference by using the monitoring thickness difference; and finally, a self-adaptive PI controller is used for calculating the second flow thickness control quantity. According to the method, the error of the second flow of the inlet and the outlet and the speed difference between the inlet tension roller and the first rack are compensated, and the monitoring thickness difference correction is used, so that the high-precision outlet thickness difference value can be obtained. Proportions and integral parameters which change adaptively along with the speed and the response time of the adjusting mechanism are used to adapt to different working conditions, so that good control performance can be kept in the rolling process, and the overall precision of the second flow AGC is improved to a large extent.

The invention relates to the technical field of boiler energy conservation, in particular to a gas boiler flue gas fan intelligent regulation and control method which comprises the following steps: S1, collecting the temperature of gas and the wind speed parameter information of a fan inlet in real time, and smoothing the collected temperature parameter and wind speed parameter to obtain a temperature smooth value Tfilt and a wind speed smooth value vfilt; s2, calculating a total correction coefficient Ktotal according to a temperature smooth value and a wind speed smooth value by taking the temperature of the fuel gas and the inlet wind speed of the fan as influence items on the rotating speed of the fan; s3, correcting the reference rotating speed of the fan according to the total correction coefficient Ktotal to obtain a target rotating speed narget; and S4, smoothing the target rotating speed narget to obtain the output rotating speed of the fan. According to the method, through a multi-parameter cooperative regulation and control strategy, it can be ensured that the draught fan always operates near the optimal state under various working conditions, and the overall heat efficiency of the gas boiler and the operation efficiency of the draught fan are remarkably improved.

A kind of thickness control compensation method for ultra-high strength steel cold continuous rolling acceleration and deceleration process, by the evaluation model based on strip outlet thickness out-of-tolerance rate set, in combination with the actual value of each rack rolling force, each rack inlet speed, each rack outlet speed, each rack inlet thickness, each rack outlet thickness, the optimization evaluation of set front tension and set rear tension is completed, according to the evaluation result, the optimization of front tension and rear tension set value is completed, and the thickness control compensation of ultra-high strength steel cold continuous rolling acceleration and deceleration process is completed accordingly.A kind of thickness control compensation method for ultra-high strength steel cold continuous rolling acceleration and deceleration process according to actual multidimensional data and in combination with the evaluation model set, establishes the thickness control compensation optimization based on multiple factors.

The application provides a controllable external excitation generation device based on aerodynamic disturbance, and relates to the field of combustion stability test of an aero combustion chamber. The device generates vortex shedding through a spoiler target, and controls excitation frequency and excitation strength by adjusting the blockage ratio of the spoiler target and the flow velocity. At present, the excitation mode of the inlet velocity disturbance of the combustion chamber generally adopts a loudspeaker for excitation. However, under the high-temperature and high-pressure operating conditions of an aero-engine, the excitation capacity of the loudspeaker is greatly limited, and it is difficult to meet the test requirements in engineering. The controllable external excitation generation device based on aerodynamic disturbance has good applicability under high-temperature and high-pressure conditions, and has a relatively simple structure. In the use process, there is almost no loss, and no external energy needs to be added. The use stability is strong, the scientific research period can be reduced, and the scientific research fund can be saved to a certain extent.

The utility model discloses a double-shell multistage centrifugal pump, an inner shell is formed by enclosing a first shell and a second shell which are detachable and is arranged in an outer shell, a rotor part is arranged in the inner shell, and the first shell and the second shell are detached, so that the whole rotor part can be taken out and is convenient to disassemble, assemble and maintain; a first-stage impeller in the rotor component is composed of double-suction impellers, the inlet flow speed of fluid can be reduced so as to improve the cavitation resistance, then the first-stage impeller is matched with a first set of impellers and a second set of impellers which are composed of symmetrically-distributed single-suction impellers, the hydraulic loss in the pump can be reduced, and therefore the overall efficiency of the pump is improved, and the axial force is balanced; a transition flow channel formed in the inner shell is of a symmetrical double-volute structure, the structure is simple, the casting cost is low, fluid can be evenly distributed into the two volutes, radial force is effectively reduced and balanced, noise and vibration of the pump are reduced, non-uniformity of fluid flowing is reduced, and the efficiency of the pump and the operation stability and reliability of the pump are improved.

The invention provides an intelligent pneumoperitoneum system with dynamic smoke removal and constant pressure functions and a using method, the intelligent pneumoperitoneum system comprises a suction and pneumoperitoneum all-in-one machine and a double-cavity aspirator head, the suction and pneumoperitoneum all-in-one machine comprises a shell and a containing space located in the shell, and a control module, a gas supply channel and a gas recovery and purification channel are arranged in the shell; the double-cavity aspirator head is connected with the gas supply passage and the gas recovery and purification passage; the system collects smoke concentration and pressure signals in the abdominal cavity in real time through the smoke concentration detection module and the outlet pressure gauge which are integrated in the double-cavity aspirator head and feeds back the smoke concentration and pressure signals to the control module. The control module constructs a closed-loop control algorithm based on an ideal gas state equation, the suction power of the suction module and the gas inlet rate of the pressure regulating module are dynamically and cooperatively regulated, and rapid removal of smoke in an operation and dynamic stability of pneumoperitoneum pressure are achieved. Two-stage waste gas filtration is integrated, it is ensured that exhausted gas is harmless, and the integrated guarantee of clear surgical view, coherent operation and patient safety is achieved.

The application discloses a multi-component powder mixing uniformity evaluation method based on digital twinning, relates to the technical field of powder mixing evaluation, and establishes a virtual model coupled with computational fluid dynamics and discrete elements and synchronizes with monitoring data such as on-site flow, wind speed, particle count and speed, and temperature and humidity; the gas flow field and particle forced motion are iteratively solved in the virtual space to obtain the residence time, circulation trajectory and component concentration distribution of typical regions such as the injection zone, fountain zone and annular zone; the gas flow unevenness index, particle residence time error and aligned mass component are constructed, feedback control is used to correct parameters such as inlet speed, outlet pressure, gas flow direction and screw rotation speed, and the twin parameters are updated in stages according to the working condition; based on the Rasi uniformity index and variance decomposition, the evaluation result is formed, the uniformity grade, abnormal area positioning, key influence factor and traceable evaluation report are output, and a basis is provided for subsequent process parameter setting and online adjustment.

The invention relates to the field of tunnel dust removal, in particular to a parameter optimization setting method for combined tunnel pre-dust-removal equipment and the combined tunnel pre-dust-removal equipment. The parameter optimization setting method comprises the steps that S1, the inlet size and the barrel diameter are calculated based on the single-inlet air volume and the inlet air speed, and gas-phase and gas-solid two-phase flowing is simulated; parameters such as exhaust pipe insertion depth, cylinder height range and cone height are determined; s2-S3, by adjusting the ratio of the height of a cylinder cone to the diameter of a cylinder, the ratio of the diameter of an exhaust pipe to the diameter of the cylinder and the like, the optimal ratio with the least escape particles and the highest separation efficiency is selected; s4, comparing velocity fields, pressure fields and efficiencies of the cyclone dust collector and the combined equipment, and selecting optimal equipment; and S5, fixing size parameters, adjusting the connection angle of each stage, and selecting the optimal angle with the highest separation efficiency. On the basis of an equipment structure optimization principle, the high-efficiency combined tunnel pre-dedusting equipment suitable for tunnel dedusting is obtained through the parameter optimization setting method.

The invention relates to the technical field of gas-solid separation, in particular to a cyclone separator inlet flow on-line measuring method and device, and the cyclone separator inlet flow on-line measuring method is carried out according to the following steps: measuring pressure and gas temperature in a cyclone separator exhaust pipe through a dynamic pressure sensor and a temperature sensor which are arranged on the inner side of a flow channel of the cyclone separator exhaust pipe; determining the dominant frequency of the instantaneous pulsating pressure of the pipe wall of the exhaust pipe of the cyclone separator, and calculating the inlet speed of the cyclone separator; the outlet flow of the exhaust pipe of the cyclone separator is measured, the conversion coefficient of the outlet flow of the exhaust pipe is determined through the gas state equation, and the inlet flow of the cyclone separator is measured in real time in combination with the inlet speed of the cyclone separator. The dynamic pressure sensor and the temperature sensor are arranged on the exhaust pipe of the cyclone separator, the inlet flow of the cyclone separator is measured in real time, the measurement result is accurate, the device is simple in structure, and the device is particularly suitable for the high-temperature and high-pressure measurement environment.

This invention provides a method for arranging baffles in a high-pressure hydrogen storage tank based on the jet dissipation transition point, and a hydrogen storage tank in the field of hydrogen storage. The method includes: establishing a baseline flow field of the high-pressure hydrogen storage tank under conditions where no baffles are installed; obtaining the axial velocity distribution and turbulent kinetic energy distribution along the central axis of the high-pressure hydrogen storage tank in the baseline flow field; identifying the location where the turbulent kinetic energy of the fluid first reaches its peak value in the region where the ratio of axial velocity to fluid inlet velocity first decays below a preset ratio threshold, and determining this spatial location as the jet dissipation transition point; arranging baffles at the jet dissipation transition point, or arranging baffles within a preset axial range near the jet dissipation transition point. This method can determine a more optimal baffle position. By arranging the baffles at the jet dissipation transition point, the residual axial kinetic energy of the jet is efficiently converted into radial turbulent kinetic energy, inducing large-scale vortex structures, thereby significantly enhancing downstream wall heat transfer.

This invention provides a centrifugal impeller comprising: a hub; multiple blades disposed on the hub and distributed circumferentially along the hub; each blade having a root and a tip; from the inlet to the outlet direction of the flow channel, the mid-arc installation angle of the blade root first increases and then decreases; the mid-arc installation angle of the blade tip first increases and then decreases, and the mid-arc installation angle of the blade root at the flow channel inlet is greater than the mid-arc installation angle of the blade tip, while the mid-arc installation angle of the blade root at the flow channel outlet is equal to the mid-arc installation angle of the blade tip. Through the design of the blade root and tip profiles, the inlet velocity of the centrifugal impeller is maintained at a low level, and the outlet installation angle of the impeller is increased, thus maintaining a high isentropic efficiency at the operating point and reducing the power consumption of the centrifugal impeller.

The purpose of this invention is to provide a one-dimensional prediction method for the characteristics of a multi-stage axial-flow transonic turbine based on dimensionless numbers, comprising the following steps: turbine characteristic calculation; angle-of-attack loss calculation; total pressure loss calculation using a loss model; lag angle calculation using a lag angle model; transonic position determination; transonic cross-sectional characteristic parameter calculation; iterating the above process until the required accuracy is met, thus completing the characteristic prediction at the operating point. This invention's one-dimensional prediction method for the aerodynamic characteristics of a multi-stage axial-flow transonic turbine based on dimensionless numbers can plot turbine characteristic curves using turbine inlet velocity, inlet mass flow rate, and total expansion ratio as the abscissas; it can predict turbine design and non-design operating conditions; the method simultaneously considers the influence of angle of attack and lag angle, and incorporates a loss model; this method can simultaneously predict the characteristics of subsonic and transonic turbines; furthermore, this invention improves the accuracy of turbine characteristic prediction and shortens the design cycle of axial-flow turbines.

The invention discloses a plasma burner based on active decoking and air film protection, the plasma burner comprises a burner main body, a first-stage cylinder and an air powder pipeline, the inlet section of the first-stage cylinder is set to be of a horn-shaped flaring structure so as to reduce the flow speed of a pulverized coal airflow inlet and reduce the impact of molten ash particles on the cylinder wall; an annular wall-attached air cavity is formed in the horn-shaped flaring structure, and a slit type air outlet is formed in the inner wall of the horn-shaped flaring structure and used for forming a wall-attached cooling air film, so that cylinder wall cooling and molten ash isolation are achieved. A mechanical rotary propelling decoking device is integrated on the burner main body and comprises a driving motor, a trapezoidal screw rod, a screw rod nut and a rotary outer protective pipe, a decoking head is fixed at the front end of the rotary outer protective pipe, the screw rod nut is fixedly connected with the rotary outer protective pipe, and the trapezoidal screw rod drives the decoking head to rotate and axially feed when rotating and extends into the first-stage cylinder to execute decoking operation. Passive prevention and active removal are combined, the operation stability of the combustor is remarkably improved, and the service life of the combustor is remarkably prolonged.

The invention discloses a multi-component powder mixing uniformity evaluation method based on digital twinning, and relates to the technical field of powder mixing evaluation, and the method comprises the steps: building a virtual model for calculating fluid dynamics and discrete element coupling, and synchronizing the virtual model with monitoring data such as field flow, wind speed, particle counting and speed, temperature and humidity; iteratively solving the airflow field and particle stress motion in the virtual space to obtain the residence time, the circulation track and the component concentration distribution of typical areas such as an injection area, a fountain area and an annular space area; constructing an airflow non-uniformity index, a particle retention time error and an alignment mass component, correcting parameters such as an inlet speed, an outlet pressure, an airflow direction and a screw rotating speed by adopting feedback control, and updating twin parameters in stages according to working conditions; and an evaluation result is formed based on the Raschig uniformity index and variance decomposition thereof, and a uniformity level, abnormal region positioning, key influence factors and a traceable evaluation report are output, so that a basis is provided for subsequent process parameter setting and online adjustment.

The invention belongs to the field of iron and steel smelting, and particularly discloses a dust nodulation prevention device and method for a belt type roasting machine based on reduction magnetic attraction. The device comprises a roasting machine body, a flue, an air pipe, a combustion chamber, an air injection device used for injecting reducing gas into the flue and / or the air pipe, and a rolling magnetic suction device used for adsorbing fine particle dust. The air pipe is provided with the first pipe section which inclines upwards in the airflow flowing direction, a part of fine particle dust can be retained through the first pipe section and does not enter the combustion chamber, meanwhile, the reducing gas is sprayed through the gas spraying device, iron oxide accounting for most of the dust can be reduced into metal iron, and the metal iron is adsorbed by the rolling magnetic suction device and conveyed out of the air pipe; therefore, dust nodules in the combustion chamber are reduced. According to the method, dust can be blown out of the combustion chamber by controlling the air inlet speed of the combustion chamber, it can be guaranteed that a large amount of dust is conveyed out of the combustion chamber by controlling the spraying amount of reducing gas, and nodules in the combustion chamber can be reduced.

The utility model relates to the technical field of fluidized bed boilers, and discloses a circulating fluidized bed boiler with a high-temperature separation function, which comprises a hearth, a boiler barrel device, an air distribution device, a separator, a return feeder and a tail flue, the separator adopts a high-temperature cyclone separator design, an inlet of the separator is in an inclined and tapered form, a central barrel is arranged at the top of the separator, and the tail flue is arranged in the central barrel. An inlet is formed in the left side of the separator. According to the utility model, by optimizing the design of the high-temperature cyclone separator, the separation efficiency is improved to more than 99.5%, the fine ash share is increased, the flow rate of a flue gas inlet is effectively improved, the speed of external swirling air flow is increased, and the air flow field is optimized, so that the separation efficiency is obviously improved; according to the bell jar type coal-leakage-free air cap, through multi-dimensional innovation and optimization of the structure, the material, the air distribution performance, the maintainability and the like, the operation efficiency and stability of the boiler are remarkably improved, meanwhile, the maintenance requirement is reduced, and a guarantee is provided for safe and efficient operation of the circulating fluidized bed boiler.

The invention relates to a regulating valve prediction model construction method based on instantaneous multi-opening response. According to the method, a multi-opening-degree three-dimensional model is constructed based on actual structure parameters, and flow field data including outlet pressure, steam volume fraction and outlet speed are obtained through CFD transient simulation. The time, the opening degree and the inlet speed are used as input, the outlet parameters are used as output, a multi-layer feedforward neural network is adopted to establish an agent model, and a Levenberg-Marquardt algorithm is used for training and optimization. The established model can quickly predict the valve flow response under any opening degree and time conditions, has the characteristics of high efficiency, good precision, strong generalization and the like, and is suitable for real-time state prediction, intelligent control and optimization design of the regulating valve.

A device for exchanging thermal energy with ambient air including a heat exchanger, a fan arranged downstream for conveying air flow through the heat exchanger, and an air supply unit with at least one air inlet opening and an air discharge unit with an air outlet opening for discharging the air flow out of the fan into the environment. The air inlet opening and the air outlet opening are arranged on the same side of the device. The air supply unit has a supply air channel feeding into the heat exchanger, which extends along an inlet surface of the heat exchanger and continuously tapers along the inlet surface, and the outflow cross-section, defining the outlet speed of the air flow, of the air outlet opening is smaller than the inflow cross-section, defining the inlet speed of the air flow, of the at least one air inlet opening.

The application discloses a combustion chamber with a self-adaptive anti-speed distortion diffuser, which comprises a combustion chamber outer shell, a flame tube and a diffuser, the diffuser is arranged at the front end of the combustion chamber outer shell and is connected with the combustion chamber outer shell, the flow passage section of the diffuser gradually increases along the air inlet direction, the end of the diffuser is provided with a rotatable swirler, the swirler rotates under the air inlet blowing, and the projection of the swirler on the flow passage section of the diffuser occupies a part of the flow passage section. The swirler is arranged, the rotating speed can be self-adaptively changed according to the inlet airflow speed, the blocking ratio is changed, the gradually expanding diffuser is matched, the combustion chamber can adapt to different inlet speed conditions, the speed distortion is resisted, the pressure loss is reduced, the flow field is stabilized, and the combustion is stabilized.

The invention discloses a rotating wheel resonance risk assessment method based on blade Karman vortex three-dimensional calculation, and belongs to the technical field of hydraulic machinery, and the method comprises the steps: obtaining speed field and pressure field data based on hydraulic machinery main runner global flow simulation; establishing a runner inlet speed fitting function and a runner outlet pressure fitting function through layered sampling and polynomial fitting; performing runner blade single-runner flow simulation by taking the fitting function as a boundary condition, and monitoring pressure pulsation data caused by Karman vortex shedding; performing spectral analysis on the pressure pulsation data, and determining Karman vortex shedding frequencies at different spanwise positions of a blade outlet; and in combination with the inherent frequency obtained through leaf water wet modal analysis, the resonance risk is evaluated through frequency comparison, high, medium and low risk points are marked, and a risk report is generated. According to the method, the Karman vortex frequency is directly extracted through full-three-dimensional flow simulation, dependence on empirical parameters is eliminated, three-dimensional flow field characteristics and spanwise frequency distribution are accurately captured, and active pre-judgment of resonance risks in the design stage is achieved.