2102 results about "Back pressure" patented technology

The invention belongs to the technical field of radial forging machine control, and particularly relates to a high-precision radial forging machine control system and a control method thereof.The method comprises the steps that a technological parameter database is established, dynamic parameters in the forging process are synchronously collected through a multi-source heterogeneous sensor, and workpiece surface temperature field distribution is obtained through an infrared thermal imager; measuring radial deformation through a laser displacement sensor group, and capturing internal defect characteristics of the material by using an acoustic emission sensor; the optimal forging frequency is calculated according to real-time material rheological characteristics, and a model predictive control algorithm is adopted to generate hammerhead motion trail correction; dynamic compensation control is implemented, and the back pressure of the hydraulic system is adjusted through strain rate feedback; and closed-loop quality evaluation is executed, online metallographic analysis is carried out in the forging intermittent period, process parameters are reversely corrected according to the grain size detection result, the fatigue life of the workpiece is predicted based on a digital twin model, and the effects that the whole forging process is dynamically controlled in real time, errors and deviation are effectively eliminated, and the forging precision is improved are achieved.

Embodiments include a choke system that passes enlarged debris despite having a relatively small diameter for an input port of the choke system. Embodiments also include systems to prevent dislodging of a choke seat when backpressure is supplied to the choke system. Embodiments also include sealing systems to prevent fluid leaks around the choke seat of the choke system.

The invention discloses a hydraulic loading system for a semi-physical simulation platform of an excavator. The hydraulic loading system comprises a loading pump set, a confluence switching valve set, a movable arm linkage loading valve set, a bucket rod linkage loading valve set, a bucket linkage loading valve set, a rotation linkage loading valve set, a flow detection assembly, a pressure detection assembly, a multi-way valve and an excavator power unit. Oil inlet ports of all the multi-way valves provide oil inlet through an excavator power unit, flow of oil return ports of a movable arm link, a bucket rod link and a bucket link provides an oil source through a loading pump set, loading valve sets simulate loading load pressure, and the oil return amount and the oil return back pressure are controlled through speed regulating valves of all the loading valve sets. And the rotary unit controls the oil return quantity and simulates the rotary load through a rotary loading valve group. Multi-pump-set loading is adopted, the loading flow range is large, universality is high, an execution oil cylinder and an execution motor do not need to be installed and replaced, and operability is high; the oil inlet and return flow and pressure of the movable arm unit, the bucket rod unit and the bucket unit are independently loaded and are not limited by the area ratio of two cavities of an oil cylinder.

The intelligent control method comprises the steps that a plurality of sensors and frequency converters are installed and used for monitoring the air temperature and humidity, the moisture content and the front-back pressure difference of a fresh air filter in real time; regulating and controlling the rotating speed of an air feeder, the rotating speed of a regeneration fan and the rotating speed of a rotating wheel through a frequency converter, obtaining sensor data under corresponding rotating speeds, and establishing an air supply quantity model, a fresh air quantity model and a rotating wheel dehumidification quantity model; the power of an air feeder, the front-back pressure difference of a fresh air filter and air parameter data are collected in real time, and the current dehumidification load is calculated according to a fan air supply amount model, a fresh air amount model and a preset formula; and selecting a preset control strategy to dynamically adjust the rotating speed of the rotating wheel, the rotating speed of the regeneration fan and the regeneration temperature according to the current dehumidification load and / or the rotating wheel dehumidification amount model so as to realize indoor humidity control. Start and stop can be automatically controlled and the dehumidification amount can be matched according to the actual wet load, excessive dehumidification or idle work is avoided, and the dehumidification efficiency is improved through multi-parameter cooperative control.

The utility model relates to an anti-backpressure high-precision spring safety valve which comprises a valve body, a valve seat, a valve clack, a valve rod, a guide sleeve and a spring pressure setting device, the lower end of the guide sleeve is pressed at an inlet of the valve body through a radial outer step of the valve seat, and a protruding cylinder arranged on the upper portion of the valve seat is concentrically sleeved in a guide cavity of the guide sleeve. The valve clack is sleeved in the guide cavity of the guide sleeve to form a piston type dynamic sealing structure, so that the concentricity of the valve clack and the sealing surface of the valve seat can be kept, and the sealing matching performance of a sealing pair is improved; the upper end of the guide sleeve is in sealing connection with the inner wall of the spring cavity on the upper portion of the valve body, the valve clack and the spring cavity are sealed and isolated from an outlet cavity of the valve body, back pressure of outlet cavity medium pressure on the valve clack is eliminated, and influence of corrosion of media on the spring on setting pressure is avoided. The device has the advantages of high pressure setting precision, reliable sealing performance of a sealing pair and the like.

The invention discloses an oil return buffer device and an impact test system with the same. The oil return buffer device comprises a cylinder barrel assembly, a buffer piston, an impact piston, an overflow detection loop, an oil charge detection loop and an air charge detection loop. A first inner barrel cavity, a damping hole and a buffering cavity are formed in the cylinder barrel assembly, and the buffering cavity is connected with an oil filling detection loop. The buffer piston is arranged in the first inner cylinder cavity so as to divide the first inner cylinder cavity into a first side cavity and a second side cavity. The buffer piston is provided with a second inner cylinder cavity, the impact piston is arranged in the second inner cylinder cavity to divide the second inner cylinder cavity into an oil return cavity and an air cavity, the oil return cavity communicates with the first side cavity, and the air cavity communicates with the inflation detection loop. The device has the obvious impact stage and the buffering stage, the instant impact pressure is rapidly reduced in the impact stage, the deceleration back pressure is obtained through oil pressure loss in the buffering stage, the buffering effect is obvious and easy to control, and the device is suitable for the field of high-speed large-flow oil return buffering of an impact hydraulic system.

The invention provides a backpressure adjusting method and device for a natural ventilation direct air cooling system, and the method comprises the steps: obtaining the current backpressure of a steam turbine, and executing an up-cut step sequence when the current backpressure is greater than a set backpressure first preset difference value, and the up-cut step sequence comprises the steps: setting a first target sector as a new commissioning sector, and setting a second target sector as a second commissioning sector; the control mode of the shutter opening degree of the new commissioning sector is set to be automatic adjustment within the first preset opening degree range; when the current back pressure is smaller than a second preset difference value of the set back pressure, a down-cut step sequence is executed, and the down-cut step sequence comprises the step that the control mode of the shutter of the second target sector is automatically adjusted in the first preset opening degree range from the second preset opening degree range to the second preset opening degree range till the second target sector quits operation. By controlling the automatic switching of the sectors and the automatic adjustment of the opening degree of the shutter, the automatic adjustment of the back pressure is realized, the automation degree of the back pressure adjustment is improved, the precision and efficiency of the back pressure adjustment are further improved, and the efficiency of the generator set is improved.

The invention discloses a polishing device and a polishing method for an inner curved surface of a steel casting, and relates to the technical field of cast steel production. The device comprises a main body frame and a polishing device, wherein the main body frame comprises a mounting table arranged on the main body frame; the stirring mechanism comprises a plurality of profiling plates which are mounted on the mounting table and used for stirring abrasive particle flow in the casting blank, and a plurality of rotating wheels are rotationally mounted on the inner wall of each profiling plate; the back pressure mechanism is used for driving the profiling plate to enter the casting blank; the rotating wheel is driven to rotate through resistance of abrasive particle flow, so that the abrasive particle flow completes switching between the distance from the abrasive particle flow to the central axis of the casting blank, and meanwhile, in the revolution process of the profiling plate, the abrasive particle flow in the casting blank is extruded up and down in a reciprocating mode through the action of a reciprocating mechanism; and the abrasive particle flow circularly polishes the inner wall of the casting blank up and down, so that the purposes of fully switching and contacting the abrasive particle flow and the inner wall of the casting blank, ensuring the polishing quality and improving the polishing efficiency are achieved.

The invention discloses a pump body structure, a compressor and an air conditioner, the pump body structure comprises a fixed scroll plate, a movable scroll plate, a support assembly and a supporting assembly, the fixed scroll plate, the movable scroll plate and the support assembly define a back pressure cavity, and the supporting assembly is inserted into the support assembly and can move up and down under the action of the movable scroll plate; a first gas channel is formed in the support assembly, a second gas channel is formed in the supporting assembly, the communicating area of the first gas channel and the second gas channel can be adjusted by moving the supporting assembly up and down, and then the amount of gas flowing into the backpressure cavity through the first gas channel or the second gas channel is adjusted. The current working condition of the compressor is associated with the communication area of the first gas channel and the second gas channel, and the gas inflow of the back pressure cavity is adjusted according to the operation condition of the movable scroll plate, so that the pressure of the back pressure cavity is balanced with the gas force borne by the movable scroll plate, radial leakage or overlarge friction work is avoided, noise and compressor power consumption are reduced, and the service life of the compressor is prolonged. The energy efficiency ratio is improved.

The invention discloses a high-temperature supercritical carbon dioxide steady-state jet flow experiment device and method, and the device comprises a liquid storage tank, a liquid booster pump, a plunger pump, a first mass flow meter, a second mass flow meter, a heating section, a first electric control valve, a first-stage cooler, a second-stage condenser, a back pressure valve, and a main loop system composed of related pipe fittings and equipment. The gas supply system consists of a carbon dioxide gas cylinder group, a gas storage tank, a gas booster pump and related pipe fittings and equipment; and the jet experiment section consists of a spray pipe, a second electric control valve, an electric stop valve and related pipe fittings and equipment. The invention further provides an experimental method of the device. According to the invention, the steady-state jet flow experiment research of supercritical carbon dioxide under the high-temperature condition can be realized.

The invention provides an abrasive flow polishing device and method for gear tooth surface homogenization. According to the method, tooth-shaped drainage pieces with the same shape as the gear are installed at the two ends of the upper portion and the lower portion of the gear, drainage section design is introduced, an abrasive flow medium path runner model is constructed, main parameters influencing an experiment are sampled and grouped through a Latin hypercube sampling method, abrasive flow polishing simulation is conducted in a grouped mode, and a Gaussian regression process is utilized to obtain an abrasive flow polishing simulation result. Selecting the minimum root-mean-square error of each group of PiVi data, determining the group of experimental parameters, obtaining a group of abrasive flow machining process parameters of optimal inlet pressure, back pressure and drainage section length, and finally guiding the experiment; according to the method, the influence of the inlet effect is relieved, the abrasive flow medium path runner model is constructed, a set of optimal abrasive flow machining process parameter combination is obtained, and the method is suitable for spur gears and bevel gears and high in universality.

The invention discloses a system and method for testing flow, displacement and hydraulic power of a main valve element. The system comprises two displacement sensors, a tested balance valve and a hydraulic testing assembly. A main valve core and a pilot valve core of the tested balance valve are coaxially and oppositely arranged; the two displacement sensors are coaxially fixed with the main valve core and the control piston respectively; the hydraulic test assembly detects the pressure of an oil return port A, a load oil port B, a feedback spring cavity pressure measuring port Pc and a pilot oil inlet X through pressure sensors; the load pressure, the pilot pressure and the oil return back pressure are controlled through a main load oil way, a pilot control oil way and an oil return back pressure oil way respectively, and meanwhile the flow of the oil return is measured through a flow meter. According to the invention, the flow, displacement and hydraulic force of the main valve core under different working conditions can be synchronously and dynamically measured.

The invention belongs to the technical field of back pressure valves, and particularly relates to an ultrahigh-pressure automatic control damping valve and a pressure control method thereof.The damping valve comprises a valve body, a screw and an adjusting nut which are sequentially communicated, a cavity channel is formed in the valve body, the screw and the adjusting nut, and a sealing head and a linear motion mechanism which are connected are sequentially contained in the cavity channel; a driving mechanism is connected outside the adjusting nut; a cavity is formed in the valve body, a fluid inlet is formed in the valve body, the sealing head is arranged in the cavity, and the fluid inlet is tightly attached to the front end of the sealing head. And a pressure sensor is arranged on a pipeline communicated with the fluid inlet. The method comprises the steps that the pressure value in a valve body is detected, and the detected pressure value is fed back to a control panel; the control panel controls the motor to change the size of a gap between the sealing head and the fluid inlet so as to change the pressure value. The pressure in the valve body is automatically and accurately adjusted, the stability of the pressure is guaranteed, and the abnormal condition caused by unstable pressure is eliminated.

The invention discloses a method for evaluating forced vibration stress of a blisk, which relates to the technical field of aero-engines and comprises the following steps: constructing a single-sector finite element model of the blisk and a multi-stage single-channel model of a gas compressor, and carrying out modal analysis containing prestress to obtain a Campbell graph of the blisk, a dangerous mode and a dangerous rotating speed; the method comprises the following steps: calculating steady flow fields of different back pressures at dangerous rotating speeds to obtain working points, respectively carrying out nonlinear harmonic method oscillation flow field calculation and nonlinear harmonic method static interference unsteady flow field calculation at the working points to respectively obtain aerodynamic damping and wake excitation, carrying out dot product on the wake excitation and a dangerous mode to obtain modal force, and carrying out nonlinear harmonic method oscillation flow field calculation and nonlinear harmonic method static interference unsteady flow field calculation on the modal force. And calculating forced vibration complex stress response by adopting a modal force method based on the aerodynamic damping and the modal force so as to obtain real stress response and maximum vibration stress thereof. The blisk forced vibration stress assessment method provided by the invention has important engineering significance for improving the design level and test guidance capability of the blisk.

The invention discloses an electro-hydraulic proportional lifting control device for a mining dump truck. The electro-hydraulic proportional lifting control device comprises a hydraulic oil tank, a first oil suction filter screen, a lifting oil pump, a lifting valve group, a left lifting oil cylinder, a right lifting oil cylinder, a second oil suction filter screen and a control oil pump. The invention discloses a using method of an electric-hydraulic proportional lifting control device of a mining dump truck. The operation mode of the main lifting valve is controlled by the pilot proportional valve, the impact force of the lifting action on the lifting oil cylinder and the frame is effectively reduced, meanwhile, the pressure set value of an outlet of the lifting oil pump is changed along with the load pressure, the front-back pressure difference of the main lifting valve is kept at a constant value, the stability of the carriage lifting speed is improved, and the safety of the carriage is guaranteed. The energy loss of the lifting system is effectively reduced, and the operation economy of the vehicle is improved.

The invention provides a backpressure adjusting structure and a compressor. The backpressure adjusting structure comprises a support, a movable scroll plate and a static scroll plate, the support is provided with a sealing groove extending to the bottom of the movable scroll plate, and a sealing piece is arranged in the sealing groove; the bottom of the movable scroll plate is divided into an exhaust cavity and a middle cavity by the sealing piece; the static scroll plate is provided with an adjusting assembly. The sealing piece is controlled to float up and down through the adjusting assembly, different requirements of heavy-load working conditions and light-load working conditions for the exhaust area of the movable scroll plate are met, under the heavy-load working conditions, the sealing piece blocks the exhaust cavity and the middle cavity, so that the exhaust area of the back of the movable scroll plate is the exhaust cavity area, high exhaust can be ensured, and the exhaust efficiency is improved. Under the working condition of light load, the sealing piece is communicated with the exhaust cavity and the middle cavity, the exhaust area of the back of the movable scroll plate is increased, overturning of the movable scroll plate is effectively avoided, and then the sealing performance of the pump body is improved.

The invention provides a compressor pressure relief structure, a compressor and an air conditioner. The compressor pressure relief structure comprises a first-stage compression assembly and a second-stage compression assembly. A first pressure relief channel is formed in the partition plate assembly, an assembly avoiding groove and a second pressure relief channel are formed in the second-stage air cylinder, at least part of structure of an opening and closing element is arranged in the assembly avoiding groove, and the opening and closing element can move in the assembly avoiding groove and the second pressure relief channel so that the second pressure relief channel can be communicated with or disconnected from the first pressure relief channel; the opening and closing element comprises a first end and a second end which are opposite to each other, the first end is opposite to the first pressure relief channel so as to bear the gas pressure of the first pressure relief channel, the second-stage air cylinder is further provided with a first back pressure channel, and the first back pressure channel can introduce exhaust gas of the compressor into the assembly avoiding groove; and the pressure acts on the second end so as to apply pressure to the second end. According to the compressor, the technical problem that in the prior art, a rivet pressure relief valve plate structure is adopted for a compressor, and flutter occurs can be solved.

The invention discloses an operation optimization method for a circulating water pump of a hybrid-driven coal-fired unit. The operation optimization method comprises the following steps: S1, determining an optimization target of the circulating water pump; s2, establishing a condenser mechanism model to obtain a condenser pressure theoretical value; s3, establishing a condenser error correction model, correcting an error generated by the condenser mechanism model by using a hybrid modeling method of residual error modeling to obtain a condenser backpressure hybrid model, and calculating an accurate backpressure value; s4, establishing a micro-increasing power general calculation model, calculating values of exhaust steam flow, exhaust steam enthalpy and remaining velocity loss in combination with the condenser backpressure mixing model, and calculating a micro-increasing output value of the unit by using the micro-increasing power general calculation model; and S5, operation optimization of the circulating water pump: dynamically optimizing the operation mode of the circulating water pump in combination with the condenser backpressure mixing model and the micro-increasing power calculation model. The running mode of the circulating water pump is dynamically optimized by combining the condenser backpressure model and the micro-increasing power calculation model.

The invention discloses a self-adaptive test system and method for a hydraulic power unit, and the system comprises a test bench which is provided with a fixing tool for fixing the tested hydraulic power unit; the oil tank unit is arranged in the test bed and is used for supplying oil to and pumping oil from the tested hydraulic power unit; and the counterweight test unit is arranged in the test bench, the counterweight test unit comprises a counterweight module, and the counterweight module is connected with a working oil port of a tested hydraulic power unit through a first oil path. The device is simple in structure, directly simulates the real gravity load borne by the hydraulic execution mechanism through the counterweight module, and can accurately test the lifting and descending dynamic performance and the pressure maintaining internal leakage characteristic of the power unit under the load condition. The problems that a traditional back pressure method cannot truly simulate the gravity load, and descending speed control and energy recovery performance are difficult to evaluate are effectively solved.

A rock housing for horizontal directional drilling machine includes a cylindrical housing body with walls defining a longitudinal cavity. A bearing assembly is provided as a part of the housing and is located above a bit box region of the housing. The bearing assembly is lubricated by drilling mud which flows through the drill string of the drilling machine, which mud flow is normally used for cooling the drill bit and removing cuttings. A portion of the drilling mud is diverted and passes through a gap formed between the bearing races of the bearing assembly, the gap being sized so as to create the necessary back pressure to divert the needed flow of drilling mud to the assembly.

The utility model relates to the technical field of steam turbines, and discloses a thermodynamic system of a coupling back pressure turbine for wide-load peak regulation, which is provided with a boiler, a back pressure turbine, a high-pressure cylinder, an intermediate-pressure cylinder, a low-pressure cylinder, a generator and a recovery mechanism, the boiler is respectively connected with the back pressure machine, the high-pressure cylinder and the intermediate-pressure cylinder; the back pressure machine is connected with the high-pressure cylinder; the medium-pressure cylinder is connected with the low-pressure cylinder; the low-pressure cylinder is connected with the generator; the recycling mechanism is connected with the low-pressure cylinder and the boiler and used for condensing steam discharged by the low-pressure cylinder and recycling and conveying the steam to the boiler. In a high-load operation state, the thermodynamic system, the back pressure turbine and the high-pressure cylinder operate in parallel, and the boiler conveys steam to the back pressure turbine and the high-pressure cylinder. In the thermodynamic system in a low-load operation state, the back pressure machine and the high-pressure cylinder are connected in series for operation, the boiler conveys steam to the back pressure machine, and the back pressure machine conveys steam to the high-pressure cylinder. According to the utility model, the pressure of steam entering the steam turbine during low-load operation can be improved, and the feed water temperature and the operation economy can be improved.

The utility model relates to the technical field of liquid treatment devices, in particular to a flow stability control device. A flow stable control device comprises a metering pump, a damper, a back pressure valve and a pipeline, the metering pump, the damper and the back pressure valve are all installed on the pipeline in series, the metering pump is placed in the fluid direction, the damper is located at the front end of the metering pump, the back pressure valve is located at the front end of the damper, and the metering pump, the damper and the back pressure valve are sequentially connected in series to form a continuous channel. The metering pump controls the medicament flow, the damper stabilizes the flow, reduces the influence of pressure change and pump wear, and the back pressure valve adjusts the pressure, so that stable flowing of the medicament is guaranteed, the purposes of flow control and pressure adjustment are achieved, the series design improves the dosing accuracy and stability, and efficient operation of the treatment process is guaranteed.

The invention relates to an intelligent detection method and system for the compactness of a railroad bed, and belongs to the technical field of railroad bed construction.The intelligent detection method for the compactness of the railroad bed comprises the steps that meshing processing is conducted on a target compaction area; when the road roller carries out compaction, the compaction performance index of the current compaction grid is obtained; judging whether the compaction performance index is smaller than a target compaction performance index or not; if yes, triggering back pressure processing; if not, obtaining a uniformity index of the current compaction grid; judging whether the uniformity index is smaller than a target uniformity index or not; if yes, triggering an abnormal mark; in the compaction process, whether the abnormal mark continuously appears L times or not is judged; and if yes, triggering local replacement filling early warning. The method has the beneficial effects that the compaction detection efficiency is improved, and the safety of railway operation is improved.

The invention relates to a low-temperature propellant filling system for a rocket core-level power system test. The low-temperature propellant filling system comprises a propellant supply subsystem, a ground pipeline precooling and discharging subsystem, a filling port discharging subsystem and a filling port deflating subsystem. The propellant supply subsystem is connected with the rocket body storage tank through a propellant supply pipeline of the propellant supply subsystem, and low-temperature propellant filling can be achieved; the ground pipeline pre-cooling discharge subsystem, the filling port discharge subsystem and the filling port deflation subsystem are respectively and independently connected with a propellant supply pipeline; and the connecting points of the filling port discharge subsystem and the filling port deflation subsystem on the propellant supply pipeline are respectively positioned on the propellant supply pipeline between the ground pipeline pre-cooling discharge subsystem and the rocket body storage tank. The device can prevent a large amount of low-temperature steam from entering the storage box to cause back pressure in the ground filling process, can adapt to impact vibration in the rocket body filling deformation and test ignition stage, and completes remote control to safely discharge the residual propellant of the rocket body, so that the filling index is met.

The present invention provides a scroll compressor floating back pressure structure, a scroll compressor, and an air conditioner, wherein the scroll compressor floating back pressure structure comprises a crankshaft, a movable scroll plate, and an upper bracket, wherein the movable scroll plate has a movable plate bearing seat, the crankshaft has a crankshaft eccentric portion which can be rotatably inserted into the movable plate bearing seat, the upper bracket is configured with a sleeve matching hole, and further comprises a balancing sleeve, the balancing sleeve has an inner hole and an outer circle, wherein the movable plate bearing seat can be rotatably inserted into the inner hole, the balancing sleeve can be rotatably inserted into the sleeve matching hole, the center of the outer circle coincides with the rotation center of the crankshaft, and the center of the inner hole does not coincide with the center of the outer circle, and a sealing ring is provided on the axial end face of the balancing sleeve, the radial inner region of the sealing ring has a refrigerant of a first pressure, and the radial outer region has a refrigerant of a second pressure, and the first pressure is greater than the second pressure. According to the present invention, the stability of the movable plate movement is improved, end face leakage is avoided, and the performance of the compressor is improved.

The invention discloses a comprehensive test bed and method for detecting the performance of a hydraulic element, and relates to the technical field of hydraulic element detection, and the comprehensive test bed comprises a hydraulic station, a test operation table and a PC terminal; detection units of all hydraulic elements are integrated on one device, the occupied area is reduced, the universality of the test bench is improved, performance testing of all the elements can be achieved according to the national standard, PLC control is used for replacing manual control and traditional relay control, and the testing efficiency and safety are improved. The hydraulic station is provided with the oil cooler, so that the oil temperature is not too high. In the hydraulic valve test unit, the designed oil way can use one flow sensor to meet the flow test requirements of different oil ways. The hydraulic cylinder testing unit can test the internal leakage amount of the hydraulic cylinder at the two stroke end points. The loading mode that the overflow valve provides back pressure for the hydraulic cylinders is safer and higher in reliability compared with a traditional two-hydraulic-cylinder opposite-jacking loading mode, and a hydraulic system is simplified.

The invention provides a bidirectional internal gear pump with a clearance compensation function, the bidirectional internal gear pump comprises a gear pump body, a gear pair, a radial clearance compensation assembly and an axial clearance compensation assembly, the gear pair comprises an internal gear and an external gear, and the radial clearance compensation assembly comprises a main crescent plate and two auxiliary crescent plates; the outer arc section of the main crescent-shaped plate is convexly provided with a protrusion, the inner arc section of each auxiliary crescent-shaped plate is concavely provided with a groove, the protrusion is connected into the groove, and the axial clearance compensation assembly comprises two floating side plates which are oppositely arranged on the two sides of the gear pair in the axial direction. In this way, when oil enters, stress high-pressure areas of the main crescent plate and the auxiliary crescent plate are opened to be tightly attached to tooth crests of the inner gear and tooth crests of the outer gear respectively, the low-pressure side of the auxiliary crescent plate gets close and is tightly attached to the protrusion of the main crescent plate for extrusion, and therefore the radial clearance compensation effect is achieved, and the floating side plate is tightly attached to the end face of the gear pair under back pressure to form axial clearance compensation so as to reduce the axial clearance. Therefore, the bidirectional clearance compensation effect is achieved, and the service life of the gear pump is prolonged.

According to the method and system for calculating the efficiency of the low-pressure cylinder of the steam turbine on line, under the reference working condition and multiple working conditions, parameters such as steam pressure, temperature and back pressure of an inlet and an outlet of a first stage, a second stage and a third stage of the low-pressure cylinder are collected, the efficiency of each stage and the efficiency of the low-pressure cylinder are calculated, dimensionless processing is carried out, and the efficiency of the low-pressure cylinder is calculated; and establishing a multiple regression model which takes the superheated steam stage efficiency as an independent variable and takes the low-pressure cylinder efficiency as a dependent variable. And considering the influence of the back pressure on the efficiency of the low-pressure cylinder, establishing a compensation model, and correcting the predicted efficiency of the low-pressure cylinder. In actual operation, the parameters are collected in real time, the efficiency of the current stage is calculated and substituted into the regression model and the compensation model, and the real-time efficiency of the low-pressure cylinder is obtained. According to the method, direct measurement of wet steam parameters is avoided by utilizing superheated steam stage data which are easy to obtain, real-time and accurate calculation of the efficiency of the low-pressure cylinder under different working conditions is realized, and the method can be widely applied to performance monitoring, operation optimization and fault diagnosis of a turboset.

The invention discloses a method for repairing overtemperature damage of a flame tube, which comprises the following steps of: detecting the thickness of an outlet ring and a conical part by using an ultrasonic detection device, recording a size numerical value and marking a height needing to be replaced; cutting and blanking, rounding, resistance spot welding, brazing, discharge hole machining and necessary shape correction are carried out by adopting the same material of a flame tube body or a substitute material with equivalent performance, and the outlet ring assembly is prepared; according to the thickness condition of the body, a welding gap is reserved, pre-welding cleaning is carried out, spot welding positioning and fixing are carried out on an outlet ring welding tool, and a checking fixture is adopted to confirm that the overall height meets the requirement; carrying out continuous cladding welding under argon back pressure; stress relief heat treatment is carried out; and the repaired part is subjected to sanding cleaning and penetrant testing, and the normal repairing technological process is returned after the repaired part is qualified. According to the method, the composite cooling structure flame tube seriously damaged by overtemperature can be repaired, the repaired flame tube has the re-operation condition, the service life of parts is prolonged, and the operation and maintenance cost of a unit is reduced.

The utility model relates to a dynamic and static pressure mixed thrust bearing structure which comprises a back plate, the back plate is of a hollow cylinder structure, a plurality of fan-shaped bosses are evenly distributed on the front face of the back plate at intervals in the circumferential direction, a gasket and a bottom foil are arranged between every two adjacent fan-shaped bosses, fan-shaped flat foils are arranged on the gaskets and the bottom foils, and pressure equalizing grooves are formed in the fan-shaped bosses. The pressure equalizing groove is an arc-shaped groove, air outlet holes are formed in the pressure equalizing groove, the air outlet holes are connected with air inlet holes through air supply flow channels, the air supply flow channels are located in the back plate, and the air inlet holes are located in the outer wall of the back plate. The dynamic and static pressure hybrid bearing provided by the utility model is of a multi-tile structure, and the flexible foils and the steps with the air inlet holes are distributed in a staggered manner. The working back pressure of the bearing can be improved through external high-pressure air supply of the air inlet holes, the dynamic pressure effect is improved, abrasion of the bearing during starting and stopping is avoided, and therefore the bearing capacity and rigidity of the bearing are improved.