22 results about "Specific speed" patented technology

The invention provides a cold machining manufacturing method of an ultra-fine grain seamless steel pipe. The method comprises the following steps: firstly, selecting a low-alloy structural steel billet with specific components, which comprises C, Si, Mn and microalloy elements of Nb, V and Ti, and heating, perforating and hot-rolling to prepare a pierced billet; and then multi-pass cold deformation treatment is carried out, 5-8 times of cold drawing or cold rolling is carried out on the pierced billet, the deformation of each pass is not lower than 30%, the cold drawing or cold rolling is carried out at the room temperature at the specific speed, and natural cooling is carried out between the passes. Recrystallization annealing is carried out after each pass of cold deformation, heat preservation is carried out for 1-2 hours at the temperature of 650-750 DEG C, and then controlled cooling is carried out. And finally, a finished product is obtained through straightening, head and tail cutting and nondestructive testing. According to the method, through cyclic cooperation of multi-pass cold deformation and recrystallization annealing and the effect of synergistically inhibiting grain growth of microalloy elements, the internal structure of the steel pipe is fully refined and homogenized, and then the comprehensive mechanical properties of the strength and toughness of the finished seamless steel pipe are remarkably improved; and meanwhile, the technological process is stable and controllable, and the product surface quality is excellent.

The utility model relates to the technical field of horizontal mixers, in particular to a horizontal reverse double-helix mixer device which comprises a mixer body, a double-helix mixing mechanism is arranged on the mixer body, the double-helix mixing mechanism comprises fixing plates symmetrically arranged on two sides of the mixer body, a first motor is fixedly mounted on each fixing plate, and a second motor is fixedly mounted on each fixing plate. A spiral shaft extending into the mixer body is mounted at the output end of the first motor; through the arrangement of the double-spiral mixing mechanism, the two oppositely arranged spiral shafts are used for mixing materials in the mixer body to form a movement overlapping area, the movement speed of the materials is higher than that of the materials at other parts, and after the materials are lifted up at a specific speed, the materials can be fully diffused and mixed in the movement process, so that the mixing efficiency is improved. Meanwhile, when the materials are discharged, the materials can be driven by the spiral shaft to be pushed to the discharging opening in the middle from the two sides at the same time, the discharging speed of the materials is increased, and residues of the materials are remarkably reduced.

The invention relates to the technical field of centrifugal pumps, in particular to an ultra-low specific speed unit transient pressure fluctuation suppression system and method.The method comprises the steps that a segmented broken line type guide vane closing rule is optimized, and decision variables are determined; determining a unit rotating speed water head ratio item in the target function of the multi-target optimization of the guide vane closing rule; according to the method, the'segmented broken line law 'of closing of guide vanes is optimized through a multi-target genetic algorithm, the'rotating speed water head ratio' is taken as a key regulation and control index, transient pressure fluctuation and runner hydraulic thrust are balanced, and the transient pressure fluctuation and the runner hydraulic thrust are controlled. The method is suitable for controlling transition processes such as starting, stopping or sudden load change of an ultralow-specific-speed unit, vibration and noise in the operation process of equipment can be reduced, the service life of the equipment is prolonged, the production efficiency is improved, equipment failures and safety accidents caused by pressure fluctuation are avoided, the production risk is reduced, meanwhile, energy waste is reduced, and the production cost is reduced.

The utility model relates to a kind of monotonic power type centrifugal impeller of medium-high specific speed and centrifugal pump applying it, solve the problems, such as the characteristic that power cannot present monotone increasing when high specific speed or need additional structure or component to generate high cost of prior art, the technical scheme used includes front cover, back cover, the equal angle distribution of several blades along circumferential direction being set between the front cover and back cover, it is characterized in that the blade is backward-inclined twisted blade, the convex surface of the blade is pressure surface, the concave surface of the blade is non-pressure surface, the water outlet end of the blade is axially inclined arrangement, parallel line parallel to impeller axis is made through the water outlet end surface of the blade, the water outlet end surface of the blade and the parallel line between there is included angle α, 0°≤α≤30°.Its effect: change the shape of blade, so that the impeller of medium-high specific speed presents monotone increasing characteristic, and does not additionally increase external structure or component, can effectively control reasonable cost.

The application belongs to the technical field of ventilator impellers, and discloses a high specific speed centrifugal ventilator impeller, which comprises a mounting disc, one end outer surface of the mounting disc is fixedly provided with an air inlet cylinder, and the other end of the mounting disc is fixedly provided with a center wheel disc, the outer surface of the mounting disc is provided with an air inlet channel, the outer surface of the center wheel disc is fixedly provided with blades, and the blades are integrally made of nanometer composite materials. The high specific speed centrifugal ventilator impeller is characterized in that the blades are designed in an arc shape, the inner concave side is provided with a flow guide groove and an arc concave angle, and the blades are designed in a variable cross-section, and the cross-section area decreases according to a specific exponential function law, which makes the airflow flow more smoothly on the surface of the blades, effectively reduces the thickness of the airflow boundary layer, reduces the flow resistance, reduces the airflow impact loss, optimizes the airflow flow state, and further significantly improves the energy conversion efficiency. Compared with the traditional impeller, the ventilator can realize greater air volume output under the same power consumption.

The present application relates to the technical field of fluid machinery, and provides a method and apparatus for hydraulic design of a volute of a feed pump of a mineral slurry preheater, and an electronic device. The method comprises: determining a base circle diameter on the basis of an impeller diameter and a pump specific speed; determining the width of a volute on the basis of an impeller flow passage width, an impeller shroud thickness, and an impeller back vane height; determining the heights of different cross sections on the basis of the area of a cross section VIII and a flow volume of a feed pump, an average flow rate of a medium passing through the cross section VIII, a volute cross‑section top arc radius, and the width of the volute; determining the area of a throat cross section of the volute on the basis of the area of the cross section VIII and the pump specific speed; determining a throat width at a volute tongue cross section on the basis of the area of the throat cross section and the volute cross-section top arc radius; and determining a hydraulic design result of the volute on the basis of the base circle diameter, the heights of different cross sections, and the throat width at the volute tongue cross section. The present application can achieve the purpose of designing parameters of a volute of a feed pump of a mineral slurry preheater, thereby improving the pass rate of one-time volute casting.

The invention belongs to the field of fluid machinery design, and particularly relates to a design method for widening an efficient area of a small-flow low-specific-speed multistage pump, which comprises the following steps of: S1, determining a flow amplification coefficient Kq, a specific-speed amplification coefficient Kns and a reference lift ratio Rb; s2, calculating a lift correction factor Fs based on the specific speed amplification coefficient Kns; s3, calculating a dynamic lift ratio R based on the lift correction factor Fs; s4, calculating a volute section design lift Hvo and a guide vane section design lift Hva based on the dynamic lift ratio R; s5, the design flow Qv of the guide vane section is calculated based on the rated flow Qr; and S6, designing a guide vane and a guide vane section impeller by taking the guide vane section design flow Qv and the guide vane section design lift Hva as basic parameters. The core contradiction of the design of the low-specific-speed multistage pump is solved, the efficiency of a rated point is guaranteed, meanwhile, the efficient area of the low-specific-speed multistage pump is widened, the working range of the multistage pump is widened, and the working stability of the multistage pump in a small-flow area is guaranteed.

The application provides a water turbine operation characteristic acquisition method, relates to the technical field of hydropower station design, and determines a quadratic function of a water turbine to be predicted by performing quadratic function fitting on the efficiency and specific speed of the water turbine and constructing a corresponding relationship database of the rated specific speed and the quadratic function, gives different operation water heads and outputs, obtains corresponding efficiency through the expression of the quadratic function of the water turbine to be tested when the operation water head is not less than the rated water head, obtains corresponding flow through a first flow calculation formula, and actual output is equal to the output; when the operation water head is less than the rated water head, the output is updated through an output updating formula, the updated output is obtained, and iteration is stopped until the updated output and the output of the previous time are within a set range; and the water turbine operation characteristic is obtained, the problem that accurate water turbine operation characteristics cannot be obtained in the existing design stage is solved, and the application is suitable for water turbine characteristic acquisition.

This invention relates to a self-balancing multistage pump with axial force, solving the problems of high energy consumption, short lifespan, and poor operational stability caused by the large axial force generated by the equal outer diameter of the front and rear cover plates and a specific speed (ns>300) in existing technologies. The technical solution includes a pump body, an impeller string housed within the pump body, and several sets of impeller units within the impeller string. The key feature is that each impeller unit includes a guide shroud, an impeller housed in the guide cavity of the guide shroud, and the impeller comprising a front cover plate, a rear cover plate, and blades disposed between the front and rear cover plates. The outer diameter of the front cover plate is larger than that of the rear cover plate. The front cover plate mates with the bottom of the guide cavity and with the open portion of the guide cavity. Its effects are: by using an impeller with a front cover plate area larger than the rear cover plate area, and in conjunction with the guide shroud, self-balancing of the impeller axial force is achieved, making the pump operation more stable and reliable, significantly reducing power consumption, greatly improving social and economic benefits, and achieving the goal of energy conservation and emission reduction.

The invention provides a plug-in hybrid-driven gasoline engine starter, which relates to the technical field of gasoline engine starting systems and comprises an outer shell, a one-way speed reducer, a motor, an energy storage device, a release device, a protection device, a starting gear and a connecting sleeve. The device has the advantages of being reasonable and simple in structure, low in production cost, convenient to install and complete in function, the overall design gives consideration to practicability and economical efficiency, and large-scale production and assembly and use in actual application scenes are facilitated; stable speed reduction transmission of power is achieved through a specific speed reduction transmission structure, the one-way transmission matching design is matched, it can be ensured that the power is only transmitted in the preset direction, interference and damage of reverse force to internal transmission parts are effectively avoided, and the reliability of power transmission is improved; the energy storage mechanism is adopted to store elastic potential energy, quick release of power is achieved through triggering of the release mechanism, sufficient and stable power can be provided for starting of the gasoline engine, and it is guaranteed that the starting process is smooth and efficient.

This invention relates to a method for analyzing the resistance components of a waterjet-propelled ship model. First, a resistance test is conducted on the bare hull. Next, a self-propelled test is performed to determine the rotational speed of the waterjet propulsion device at a given self-propelled point. Then, an L-shaped nozzle is installed, and the waterjet propulsion device operates at the self-propelled point rotational speed at a specific speed, measuring the total hull resistance. Simultaneously, the flow field in the flow region is measured using PIV technology, and the inlet longitudinal momentum is calculated. Finally, the total resistance is subtracted from the bare hull resistance and the inlet longitudinal momentum to obtain the impact of the propeller operation on the hull resistance at the corresponding self-propelled point. This invention employs conventional resistance tests, L-shaped nozzle resistance tests, self-propelled tests, and flow field measurements in the flow region to decompose the resistance into the hull's own resistance components and the hull resistance increment caused by the suction effect of the waterjet propulsion device. This allows for the identification of the propeller's impact on the hull, reducing hull shape optimization to a single objective function optimization problem and improving hull shape optimization efficiency.

This invention discloses a dynamic calibration method for the NVH performance of an automotive air conditioning compressor, comprising the following steps: S1, compressor selection and bracket design; S2, setting compressor NVH analysis targets; S4, NVH test simulation benchmarking of the compressor bracket assembly; S5, compressor unit NVH noise test control; S6, setting compressor-wide vehicle noise and vibration targets; S7, compressor-wide vehicle noise and vibration test; S8, compressor-wide vehicle noise and vibration frequency avoidance design; S9, compressor start-stop calibration; S10, optimization of vehicle calibration strategy for environmental chamber simulation test; S11, locking of vehicle calibration strategy for environmental chamber simulation test; S12, determination of compressor verification conditions for high-altitude, high-temperature, and high-humidity tests; S13, optimization of dynamic NVH calibration of compressor for high-altitude, high-humidity, and high-humidity tests; S14, acceptance of dynamic NVH calibration strategy for compressor for high-altitude, high-humidity, and high-humidity tests. The present invention provides a dynamic calibration method for the NVH performance of automotive air conditioning compressors. By combining high-altitude, high-temperature, and high-humidity test data, and by optimizing and adjusting the compressor operating speed at specific speeds and adjusting the compressor transition speed state time control, the method improves the NVH performance of the vehicle air conditioning system without increasing hardware or costs. This achieves a globally optimal balance between air conditioning performance and ride comfort, meeting the development requirements for NVH ride comfort.

The utility model discloses a spiral grading conveying device, the utility model relates to the technical field of conveyer industry technology. This spiral grading conveying device, including power mechanism, gear transmission mechanism, conveying crushing mechanism, grading screening mechanism, unloading mechanism and outside shell mechanism, conveying crushing mechanism and grading screening mechanism all are located inside outside shell mechanism, the unloading mechanism is located outside shell mechanism outside, the unloading mechanism is fixed through the connection technology effect with the lateral surface of grading screening mechanism on the one side of grading screening mechanism outer wall, and the technical effect is through power mechanism, drives gear transmission mechanism, realizes the different specific speed of grading screening device through the adjustment of gear transmission system gear number ratio, and the greater difference of two rotational speeds, the better conveying crushing effect, and the higher smaller particle ratio obtained, the spiral blade can adjust according to the material property, and more material characteristics are adapted, and the function is more, and the cost is lower compared with the same performance.

The application discloses a multi-curvature optimized drag-reducing lateral thruster flow guide groove, and the opening (5) of the lateral thruster (1) is designed in the form of a horn-shaped flow guide groove (6). The application is based on the large-curvature characteristics of a ship line, and according to the water flow direction and the transverse gradient of the opening end, different chamfer angles are designed at different positions, multi-curvature transition and optimization are applied, and a multi-curvature optimized drag-reducing lateral thruster flow guide groove is designed. The application has the advantages that the cutting amount of the structure is reduced, the strength of the structure is retained, and the safety of the structure is ensured. According to the comparison of CFD software, under the specific speed working condition of the actual ship, the flow guide groove of the application reduces the pressure near the side thruster opening, and the overall ship resistance is reduced by 3.2%.

This invention discloses a hydraulic design method and system for impeller-guide vane coupling matching of high specific speed submersible axial flow pumps, belonging to the field of fluid machinery technology. The method includes the following steps: S1, accurate calculation of impeller diameter; S2, hub ratio graded optimization; S3, blade cascade density collaborative design; S4, blade comprehensive parameter design; S5, guide vane hydraulic quantitative design; S6, dynamic coupling matching of impeller and guide vane. It aims to overcome the inherent defects of existing high specific speed submersible axial flow pump hydraulic design technology, and fundamentally solves the problems of large deviations in actual pump performance and poor adaptability across wide specific speed ranges caused by reliance on model pump similarity conversion in existing technologies. Simultaneously, it addresses the problems of excessive pressure pulsation and insufficient operational stability caused by the lack of impeller-guide vane coupling matching in existing designs, as well as the industry pain points of parameter values ​​lacking systematic theoretical support and the inability to simultaneously achieve high efficiency and cavitation resistance due to empirical design.

The invention provides a dual-channel impeller-double volute structure suitable for an extremely low specific speed centrifugal hydrogen compressor, which comprises a vaneless diffuser, a dual-channel impeller and a double volute, the vaneless diffuser comprises a hub side part and a rim side part, the rim side part comprises an equal thickness section and an expansion section, and the expansion section is connected with the hub side part. The rim side part and the hub side part jointly form a diffuser outlet; the equal-thickness section is closely connected with an outlet of the double-channel impeller, and the outer diameter of the expansion section is gradually expanded in the airflow direction; the double-channel impeller is a closed impeller formed by connecting a hub and a wheel cover through bolts, and airflow flows out through an impeller channel and then enters the vaneless diffuser. The double volutes comprise two centrosymmetric guide assemblies, and each guide assembly comprises a guide section and an air outlet pipe which communicate with each other; and the two guide sections cover the outer edge side of the outlet of the vaneless diffuser. In the implementation mode, the vaneless diffuser achieves adaptation and guiding of complex flow at an outlet of the double-channel centrifugal impeller, the double-channel impeller ensures that effective pneumatic loading capacity is kept under the condition of extremely small flow, and decoupling and efficient guiding of an asymmetric double-channel impeller flow field are achieved through the double volutes.

The invention belongs to the field of low specific speed mixed flow water turbine, and discloses a kind of low specific speed mixed flow water turbine runner blade split manufacturing method. The runner is divided into four parts of upper crown blade disc, lower ring inner blade disc, lower ring outer blade disc and short blade casting and processing. Long blade is divided into upper and lower two parts along the rotation cutting surface of the fitting center line of upper crown and lower ring flow channel, and the middle short blade is the remaining part of the short blade after removing the upper crown side short blade root transition step, the lower ring inner ring side short blade root transition step and the lower ring outer ring side short blade root transition step. First, the long blade is welded with radial split welding seam without short blade, then the short blade related welding seam is welded without lower ring outer blade disc, and finally the lower ring outer blade disc is assembled and welded at the runner water inlet edge. The invention can greatly improve the process accessibility of low specific speed mixed flow water turbine runner with small opening, long flow channel and multiple blades, and the design length of short blade flow channel is not limited by the runner manufacturing process, and the blade connection welding seam avoids the high stress area, improving the runner manufacturing quality and operation safety margin.

This invention provides a method for predicting the full characteristic curve of a centrifugal pump, relating to the field of centrifugal pump performance prediction technology. First, based on the Euler equation and similarity law of centrifugal pumps, a theoretical energy transfer relationship is constructed, and undetermined coefficients characterizing the theoretical operating conditions are obtained, giving the full characteristic curve prediction a physical basis and avoiding the limitations of purely empirical fitting. Next, measured full characteristic curves of centrifugal pumps with known specific speeds are introduced as samples. Through coordinate transformation and feature point identification, feature parameters are extracted, and a mapping relationship between these parameters and the specific speed is established, accurately depicting the curve morphology changes under different specific speeds. Finally, the theoretical undetermined coefficients and empirical undetermined coefficients corrected for specific speed are integrated, and the head and torque data of the target pump are continuously calculated for the entire flow rate, making the predicted curve both theoretically consistent and engineeringly applicable.

The utility model relates to the technical field of building construction, and discloses a mixing device for building construction, which comprises a first U-shaped frame, a base, a second U-shaped frame, a first rotating shaft, a second rotating shaft, a third rotating shaft, a mixing tank, a driven bevel gear and a driving bevel gear. During use, after the first rotating shaft is driven by external force to rotate, the mixing tank can continuously rotate along the axis of the first rotating shaft. And when the second rotating shaft is driven by external force to keep static, the mixing tank can continuously rotate around the third rotating shaft according to a specific speed ratio. Therefore, the mixing tank can continuously rotate along the two mutually perpendicular axes. Therefore, the materials are turned over and mixed in two directions, and the mixing effect is ensured. In addition, when the second rotating shaft is driven by external force to continuously rotate, the mixing tank can be driven to rotate around the axis of the third rotating shaft. Therefore, the rotating speeds of the mixing tank along the two mutually perpendicular axes can be adjusted respectively so as to be suitable for different mixing works, and the mixing effect is improved.

The utility model discloses a low-specific-speed vertical mixed-flow pump, which relates to the technical field of fluid machinery and is additionally provided with a sealing ring, a radial floating connecting mechanism, a filling block and an elastic sealing ring on the basis of comprising a suction horn mouth, an impeller and an impeller chamber. The sealing ring is in radial floating connection with the suction horn mouth through a mechanism formed by the cylindrical pin and the pin hole, so that the sealing ring can adapt to micro eccentricity of the impeller, the sealing radial gap between the sealing ring and the suction horn mouth is allowed to be reduced to 0.15-0.2 mm, and the volume loss is remarkably reduced. The filling block is fixed to the suction horn mouth and fills an annular space between the impeller front cover plate and the impeller chamber, and vortex generation and vibration are effectively restrained. The elastic sealing ring is contained in an axial gap between the filling block and the end face of the sealing ring and provides axial sealing and floating buffering. According to the utility model, the efficiency and the stability of the pump are greatly improved while the operation reliability is ensured, and the problems of low efficiency, easy vibration and easy sealing damage of the pump in the prior art are solved.

This invention discloses a reaction turbine aerodynamic design method for a full-flow staged combustion liquid rocket engine, relating to the field of liquid rocket engine technology, including the following steps: (1) obtaining aerodynamic design input parameters; (2) calculating the total isentropic expansion specific work and estimating aerodynamic efficiency; (3) selecting the number of turbine stages and determining the isentropic enthalpy drop ratio and thermodynamic reaction degree of each stage; (4) selecting the speed ratio of each stage and calculating the turbine mean diameter and specific speed; (5) calculating the aerodynamic and geometric parameters of the blade cascade; (6) drawing the cross-sectional profiles of the moving and stationary blade cascades of each stage and stacking them to form a three-dimensional blade cascade profile; (7) three-dimensional modeling of the flow path model; (8) three-dimensional aerodynamic simulation and performance analysis; (9) determining whether the aerodynamic performance meets the requirements. The reaction turbine aerodynamic design method for a full-flow staged combustion liquid rocket engine of this invention can reduce the development risk of a full-flow staged combustion liquid rocket engine and has a wide range of applications in the field of rocket engines.