811 results about "Inlet pressure" patented technology

The invention relates to the field of hydroelectric generation automation control, discloses an intelligent flow-pressure double closed-loop control method and system for a water inlet ball valve of a water turbine, and aims to solve the technical problems that flow stability and pressure fluctuation suppression are difficult to consider, dynamic response is delayed and working condition adaptability is poor in existing single-loop control. The method comprises the steps that inlet pressure and flow data are collected in real time through a pressure sensor and an ultrasonic flowmeter, a cascade structure of outer ring flow control and inner ring pressure control is constructed in combination with working condition parameters such as the rotating speed of a unit and the opening degree of a guide vane, and a working condition self-adaptive weight distribution module is introduced to dynamically adjust the double-ring gain coefficient; meanwhile, a feed-forward compensation mechanism and an optimal efficiency curve database are fused, and dynamic matching of set values and advanced response of load instructions are achieved. The system comprises a data acquisition unit, a double-closed-loop control unit, a weight distribution unit, an electro-hydraulic servo execution mechanism and a safety interlocking module, and supports microsecond-level gain updating and high-precision valve position control. According to the technical scheme, the adjusting precision and the response speed of the water turbine under the complex working condition are remarkably improved, the actual measurement efficiency is improved by 2.5%-4.8%, the adjusting time is shortened to be within 3 seconds, the positioning precision reaches + / -0.5 degree, and safe and stable operation of the system is guaranteed.

The invention provides an analysis method and device for flow, efficiency and water consumption rate of a hydraulic power plant generator set. A distributed flow measurement unit based on a domestic PLC controller and a domestic operating system is constructed, and each unit is independently configured with the flow measurement unit to realize decentralization of data acquisition and processing; active power, guide vane opening, water head difference, instantaneous flow and volute inlet pressure data are collected in real time through a distributed flow measurement unit, and a unit efficiency and water consumption rate calculation model is dynamically fitted based on the data; sending an output result of the calculation model to a monitoring system through an anti-interference communication network, wherein the communication network adopts layered wiring and a double-shielded twisted pair to reduce the signal bit error rate; and the IMC integrated management and control platform is used for remote monitoring and diagnosis of the flow measurement unit, and seamless connection with a smart power plant data medium station is realized. The system reliability and the maintenance flexibility are improved, and the autonomous controllable requirements of domestic substitution and intelligent power plants are comprehensively met.

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.

A method for controlling a flow regulating valve (6) of a filling machine (1), controlling the flow of pourable food product, envisages: receiving an inlet pressure measurement (PIN) from a pressure sensor (14); receiving an inlet flow measurement (FIN) from a flow meter (16); determining a control signal (Sc) for controlling an operating position of the flow regulating valve (6) by combined contributions (C1, C2) of a flow feedback control module (22), receiving at its input a flow set point (FSP) and the inlet flow measurement (FIN) and generating a first control contribution (C1) indicative of a difference between the inlet flow measurement and the flow set point; and a flow feed-forward control module (20), receiving at its input the inlet pressure measurement (PIN) and the flow set point (FSP) and generating a second control contribution (C2) as a function of the flow set point and inlet pressure measurement, using pre-stored fluid-dynamic maps, which may be a result of a characterization of the flow regulating valve in a test condition. The flow feed-forward control module uses the fluid dynamics maps in a dynamically adaptive manner, depending on different operating conditions of the filling machine and / or the related pourable food product, thereby adapting to the same different operating conditions and / or the pourable food product.

The invention provides a well-station-oil depot coupling simulation-based crude oil coagulation risk optimization method, which comprises the following steps of: firstly, designing a well-station-oil depot pipe network system topological structure, analyzing a pipe network structure, and numbering wells, stations, oil depots and pipelines to obtain the numbers of an upstream pipeline and a downstream pipeline of each pipeline; then, a well-station-oil depot pipe network system is disassembled into a node + pipeline form, each pipeline is dispersed into a plurality of calculation units, and the pipe section length, diameter and dip angle of each calculation unit are obtained; according to the fluid temperature of each wellhead, the fluid entering pressure of each station and a PVT physical property table, assuming the temperature and pressure of all nodes to obtain the average temperature and pressure of each pipe section; and calculating crude oil physical property parameters, crude oil flow parameters, pressure drop and temperature drop parameters of each pipe section by adopting an iterative method to obtain pressure and temperature of all nodes, and finally judging the pipe condensation risk according to the physical property parameters and the pipeline pressure and temperature. The pipe condensation risk can be automatically judged, and the production efficiency and safety are improved.

The invention discloses a water pump control method, device and equipment for production, a medium and a product, and relates to the technical field of pump station control. The method is executed by a central control host of a water pump control system for production, and comprises the following steps of: sorting according to water pump operation parameters, a water pump water inlet pressure value and a water pump water outlet pressure value which are received in real time in a current latest time period to obtain multi-dimensional time sequence data of a current online water pump; secondly, the time sequence data are imported into a water pump fault probability prediction model which completes pre-training based on a time sequence model, and the probability that the current online water pump breaks down in the current next time period is output and obtained; and generating a water pump switching control instruction used for indicating to stop the current online water pump and start the current offline water pump, and finally transmitting the control instruction to the pump station control cabinet for execution, thereby reducing the fault probability of the whole pump station in a multi-water-pump parallel use scene of the pump station.

The invention discloses a safety valve service life evaluation method based on pressure history statistics and dynamic damage accumulation. According to the method, only safety valve inlet pressure time sequence data is needed, a load cycle is extracted through an improved rain flow counting method, and the nonlinear damage increment is calculated according to an S-N curve model dynamically degraded along with the accumulated damage degree. According to the method, a self-adaptive failure probability threshold is established based on historical failure data, and probabilistic prediction of the residual life is realized. The model is clear in physical significance, only needs a single data source, significantly reduces the implementation complexity and cost, greatly improves the precision of life prediction by considering the degradation of material performance, and is especially suitable for predicting the accelerated failure risk of the safety valve in the later period of long-term service.

The invention belongs to the field of plant extracting solution concentration, and discloses a low-pressure high-power concentration device for a plant extracting solution and a concentration method using the low-pressure high-power concentration device. The device is based on a series reverse osmosis membrane stack and a feeding pump, a fresh water collecting tank, a booster pump, three types of pressure sensors, two types of osmometers, a water inlet pressure control system and a one-way valve are additionally arranged, the three types of pressure sensors are used for detecting the pressure of a feeding header pipe, the pressure of concentrated water and the pressure of a fresh water header pipe respectively, and the two types of osmometers are used for detecting the osmotic pressure of the feeding header pipe and the osmotic pressure of the concentrated water respectively. The water inlet pressure control system adjusts the design pressure of the device and the osmotic pressure of the plant extracting solution by adjusting the frequencies of the booster pump and the feeding pump, so that accurate monitoring of parameters is realized, efficient concentration of the plant extracting solution under low pressure is guaranteed, scaling on the surface of a reverse osmosis membrane is delayed, the service life of a membrane stack is prolonged, and continuous production of membrane concentration and filtration is realized.

The invention provides a cooling device and a control method thereof, a storage medium and a program product, and relates to the technical field of cooling. The cooling device comprises a filtering system; the filtering system comprises a filter, an inlet pressure sensor, an outlet pressure sensor, a pump front switching valve, a one-way valve, a flushing pump, a sewage draining switching valve and an outlet switching valve; the filter comprises a barrel and a filter element located in the barrel, and the barrel comprises an inlet, an outlet and a drain outlet located between the inlet and the outlet; the one-way valve is arranged at the inlet, is sequentially connected with the filters and then is connected in parallel with the pre-pump switch valve and the flushing pump which are sequentially connected; the before-pumping switch valve is close to the one-way valve; the inlet pressure sensor is arranged at one end of the filtering system close to the refrigerating system; the outlet switch valve and the outlet pressure sensor are arranged at the end, close to the cooling system, of the filtering system. Automatic cleaning is achieved, manual intervention is not needed, time and labor are saved, and the service life of the filter element can be greatly prolonged.

The invention relates to the technical field of pumps, and discloses a reliable double-shell self-balancing multi-stage centrifugal pump, a low-pressure section is provided with a medium inlet and an inducer chamber, the two ends of the inducer chamber communicate with the medium inlet and a fluid cavity correspondingly, and an inducer connected to a pump shaft is arranged in the inducer chamber; the pump shaft sleeve is provided with a throttling ring, the throttling ring is located at the end, away from the low-pressure section, of the high-pressure section, drainage threads are arranged on the periphery of the throttling ring, a throttling channel is defined between the drainage threads and the high-pressure section, the mechanical seal base is provided with a pressure relief channel, one end of the throttling channel is communicated with the fluid cavity, and the other end of the throttling channel is communicated with the pressure relief channel. And the pressure relief channel is communicated with the inducer chamber through a pressure relief pipe. According to the reliable double-shell self-balancing multi-stage centrifugal pump, the throttling ring is driven by the pump shaft to rotate, the inlet pressure is effectively increased, cavitation is prevented, the throttling channel has the pressure relief effect on the high-pressure section, the impact load of a high-pressure medium on the pump shaft, the bearing and the bearing box is relieved, the operation stability of the pump is improved, and the service life of the pump is prolonged.

The invention provides a volumetric supercritical carbon dioxide Brayton cycle variable load system, belongs to the technical field of supercritical carbon dioxide Brayton cycle power generation, and can at least partially solve the problems that an existing steam Rankine cycle unit does not utilize the supercritical carbon dioxide Brayton cycle to integrally operate on a supercritical point and has no project. The Brayton cycle system comprises a compressor, a main loop and an adjusting branch, the adjusting branch comprises a pressure adjusting assembly, the amount of circulating carbon dioxide working media in the system is adjusted, the inlet pressure of the compressor is adjusted, and the working point of the compressor is changed; the temperature and pressure of the carbon dioxide working medium at the turbine inlet are changed by adjusting the heat exchange amount of the heat source heat exchanger, and rapid load changing is achieved.

The invention relates to the technical field of electromagnetic valves, in particular to an air pump electromagnetic valve capable of adaptively adjusting displacement, which comprises a valve seat, an electromagnet, an adjusting rod, a valve core and a movable piece, the interior of the valve seat is divided into an outer cavity and an inner cavity, a first communication port is arranged between the outer cavity and the inner cavity, and the movable piece in transmission connection with the valve core is arranged in the inner cavity; the valve element is connected with an adjusting rod in the electromagnet valve element through an elastic assembly, and by adjusting the installation height of the adjusting rod in the armature, it can be ensured that when the valve element is located at the preset position, the second communication opening and the first communication opening in the movable part are mutually staggered, and a throttling opening with the normal opening degree is formed; the valve element drives the movable part to move up and down, and the opening degree of the throttling opening is dynamically adjusted, so that the air outlet pressure is adaptively controlled according to the air inlet pressure, the air outlet pressure is stabilized within the set range, the problem that a traditional electromagnetic valve is difficult to respond to dynamic pressure changes is effectively solved, and constant adjustment of the outlet pressure is achieved.

The embodiment of the invention provides a calculation method and device for boundary parameters of a supercritical fluid heat exchanger, computer equipment and a medium, and relates to the technical field of fluid mechanics and heat transfer science calculation.The method comprises the following steps that design parameters and target working conditions of the heat exchanger are obtained; calculating to obtain the single section length of each infinitesimal section; based on the initial inlet pressure guess value, according to the length of the single section and the pressure and the temperature of the infinitesimal section i, the pressure and the temperature of the infinitesimal section i + 1 are obtained through calculation, the difference value between the outlet calculation pressure and the target outlet pressure is calculated, and the difference value serves as a pressure error; if the pressure error is greater than the convergence tolerance, updating the inlet pressure guess value by adopting a numerical iteration method, and performing iteration again based on the inlet pressure guess value after iteration; otherwise, iteration is terminated, and the final inlet pressure value and the final outlet temperature value are output. According to the scheme, the calculation efficiency and accuracy of solving the inlet pressure and the outlet temperature of the supercritical fluid heat exchanger under the given target outlet pressure are improved.

The invention relates to the technical field of waste gas treatment, and provides an oil tank waste gas adsorption treatment system and a control method. The anti-explosion variable-frequency induced draft fan is arranged on the main oil and gas pipeline; the flame arrester is arranged on the main oil and gas pipeline and located on the upstream of the air inlet direction of the anti-explosion variable-frequency induced draft fan; a gas inlet of the first activated carbon adsorption box is communicated with the main oil-gas pipeline, and a gas outlet of the first activated carbon adsorption box is communicated with a gas inlet of the second activated carbon adsorption box in series; the inlet pressure sensor is arranged at the air inlet end of the first activated carbon adsorption box; the outlet pressure sensor is arranged at the air outlet end of the second activated carbon adsorption box; the inlet valve is arranged at the air inlet end of the first activated carbon adsorption box, and the outlet valve is arranged at the air outlet end of the second activated carbon adsorption box. Through cooperation of series adsorption, active air induction and intelligent monitoring, multiple functions of efficient purification, safe operation and state early warning of the oil tank waste gas adsorption treatment system are achieved.

The embodiment of the invention provides an engine supercharging system and a vehicle, and relates to the technical field of vehicle manufacturing. The electronic supercharger is constructed into a two-stage supercharger, the electronic supercharger is provided with a first-stage compressed air flow channel and a second-stage compressed air flow channel, a turbine compressed air flow channel is formed in the turbocharger, and the first-stage compressed air flow channel, the second-stage compressed air flow channel and the turbine compressed air flow channel are distributed in series. And the three-stage compressed air inlets are communicated with the air inlet to form three-stage compressed air inlet to the air inlet. According to the engine supercharging system provided by the embodiment of the invention, gas can be supercharged for three times through the first-stage compressed air flow channel, the second-stage compressed air flow channel and the turbine compressed air flow channel, so that the air compression ratio can be increased, the turbine hysteresis phenomenon is avoided, the air inlet pressure response speed is increased, and transient air supply to an engine is ensured; the operation stability and combustion efficiency of the engine are guaranteed, the fuel economy of the engine is improved, and the driving experience is improved.

The application discloses a kind of anti-surge control methods for compressor unit, specifically relates to the field of compressor unit operation control, the application is deployed pressure, flow, temperature and other various sensor terminals in the installation and commissioning phase of compressor unit, real-time acquisition inlet pressure, flow, exhaust pressure and other working parameters, after acquisition, data is preprocessed, smooth data using moving average filtering method, according to 3σ principle washes abnormal value, according to missing proportion processing missing value and normalization, based on preprocessed data, build operating condition model, combined with inlet flow and exhaust pressure and other parameters, calculate anti-surge threshold in low, medium and high load area, at the same time, use historical data to build exhaust pressure and inlet flow prediction model, predict future state. By comparing predicted value and threshold value to judge surge state, and then adjust inlet and outlet adjusting valve opening, ensure the stable operation of compressor unit, effectively prevent surge phenomenon from occurring, improve the safety and reliability of compressor unit operation.

The invention discloses an anti-airlock method and equipment for an electric submersible screw pump based on working condition recognition and a medium, and relates to the technical field of oil exploitation equipment. The method comprises the steps that based on an underground detection device and a ground control cabinet sensor of the electric submersible screw pump unit, operation parameters of the electric submersible screw pump unit are collected in real time, and the operation parameters are preprocessed to obtain standard operation parameters; wherein the operation parameters comprise pump inlet pressure and motor output current; extracting pressure-current correlation characteristics under the airlock working condition to construct an airlock working condition identification model, and inputting the standard operation parameters into the airlock working condition identification model to obtain an airlock state grade; and based on the airlock state grade, the operation regulation and control strategy of the electric submersible screw pump unit is adjusted so as to eliminate the airlock phenomenon. Real-time data of underground and ground sensors are collected, the airlock grade is judged in advance through the airlock working condition recognition model, the operation state is automatically adjusted, and early warning of the airlock is achieved.

The invention provides a steam turbine generator unit feed pump net positive suction head detection system and method, relates to the technical field of net positive suction detection, and solves the technical problem that net positive suction is difficult to recognize in advance in the prior art. The system specifically comprises a temperature acquisition module used for acquiring the temperature of the deaerator; the judgment and early warning module is used for receiving the flow change rate of the feed pump and triggering alarm when the flow change rate exceeds a flow threshold value; the effective net positive suction head calculation module is used for converting the inlet pressure of the water feeding pump into absolute pressure; temperature correction is conducted on the temperature of the deaerator to obtain the saturation temperature of an inlet of the water feeding pump, the saturation temperature is converted into saturated vapor pressure, and the effective net positive suction head is calculated based on the absolute pressure and the saturated vapor pressure; the necessary net positive suction head obtaining module is used for calling the necessary net positive suction head table and calculating and obtaining the necessary net positive suction head; and the net positive suction head calculation module is used for receiving the effective net positive suction head and the necessary net positive suction head and calculating the net positive suction head. The device is used for detecting the net positive suction head.

The invention relates to a centrifugal compressor high-altitude environment dynamic simulation test system. The system comprises a compressor test module; the high-altitude environment simulation module comprises an air inlet surge tank, an air inlet assembly and a first air exhaust assembly which are arranged at the upstream of the air inlet pipeline, and an air exhaust surge tank and a second air exhaust assembly which are arranged at the downstream of the air exhaust pipeline; a measurement module; the control module is used for comparing the first actually-measured pressure value with a target altitude pressure value of the air inlet end and controlling the air inlet amount of the air inlet assembly and the air suction amount of the first air suction assembly according to a comparison result, so that the pressure of the air inlet pressure stabilizing tank is stabilized at the target altitude pressure of the air inlet end; and the control module compares the second actually measured pressure value with the target altitude pressure value of the exhaust end, and controls the air suction amount of the second air suction assembly according to the comparison result, so that the pressure of the exhaust surge tank is stabilized at the target altitude pressure value of the exhaust end. It is ensured that test data can truly reflect the actual plateau working condition performance of the gas compressor.

The refrigerating system comprises a compressor, an evaporative condenser, a gas-liquid separator, a heat regenerator, an evaporator, a heat recoverer, an energy storage device, a terrace heat exchanger, an oil separator, an oil cooler, a water pump, a temperature control valve, an electronic expansion valve, a three-way valve, a control device, a temperature sensor and a pressure sensor. The control device collects signals of compressor outlet and inlet pressure sensors and temperature sensors, evaporator outlet pressure sensors and temperature sensors, an oil return temperature sensor and a floor heat exchanger temperature sensor. Condensing pressure is adjusted by controlling starting and stopping of a condenser side fan and a water pump, and the opening degree of the three-way valve is controlled to enable the oil return temperature to be within a safe range. The evaporation temperature is maintained by adjusting the opening degree of an evaporator inlet electronic expansion valve. By monitoring the terrace temperature in the refrigeration house, the electromagnetic valve is controlled to adjust the refrigerant flow in the terrace heat exchanger to maintain the outlet temperature, and the energy storage device is intermittently put into the refrigeration house to improve the system energy efficiency.

The invention relates to the technical field of gas cylinder valves, and discloses a pulse type oxygen valve regulation and control device which comprises a shell, the shell is provided with at least one sunken gas inlet bin which is annularly distributed at equal angles, a rotating bin is arranged in the center of the shell, a sliding sleeve is arranged on the side face of the gas inlet bin, and the rotating bin is provided with a rotating shaft. The center of the rotating bin is rotationally connected with a rotating discharging pipe, the side wall of the rotating discharging pipe communicates with a side inlet pressure pipe, the side inlet pressure pipe is slidably connected to the interior of the sliding sleeve, and an air inlet groove is formed in the inner side wall of the sliding sleeve; the elastic coefficient of the torsion spring of the discharge pipe can be increased, under the effect of the lever principle, the acting force of gas driving the rotary discharge pipe to rotate is reduced, when the rotary discharge pipe has elastic fatigue, only the torsion spring needs to be slightly twisted, and the problem of partial elasticity loss caused by the elastic fatigue can be counteracted; the problem that the stable pressure stability is reduced due to elastic fatigue caused by long-term spring application is solved.

The invention relates to the technical field of hydraulic servo control, in particular to an integrated hydraulic execution device and method based on self-correcting force-displacement coupling, and the device comprises a hydraulic cylinder, a servo valve, a one-dimensional force sensor, a displacement sensor, an oil inlet pressure sensor, an oil outlet pressure sensor and an edge calculation unit; wherein the servo valve is mounted at an oil inlet of the hydraulic cylinder; the one-dimensional force sensor is mounted at the end of a hydraulic cylinder piston rod; the displacement sensor is arranged in the hydraulic cylinder barrel; the oil inlet pressure sensor and the oil outlet pressure sensor are respectively mounted at an oil inlet and an oil outlet of the hydraulic cylinder; the edge calculation unit is integrated on the outer wall of the hydraulic cylinder and is connected with all the sensors and the servo valve through signal lines; wherein the edge calculation unit operates a self-correcting force-displacement coupling control algorithm, residual error characteristics of all sensors are used as input, the corrected opening degree of a servo valve is output in real time, and closed-loop accurate control over the hydraulic cylinder is achieved.

The invention relates to the technical field of automatic control, and discloses a multi-storage-tank hydrogen storage and delivery system and a control method thereof, and the multi-storage-tank hydrogen storage and delivery system comprises a control module; the hydrogen conveying module comprises a hydrogen conveying pipe, a hydrogen production device flow meter and a compression assembly, the hydrogen conveying pipe is connected with the compression assembly, the hydrogen production device flow meter is arranged on the hydrogen conveying pipe, and the hydrogen conveying pipe is provided with an inlet pressure sensor and an outlet pressure sensor; the hydrogen storage module comprises a hydrogen input pipe, a storage tank main pipe and a plurality of hydrogen storage tanks, the hydrogen input pipe is connected with the hydrogen conveying pipe, the hydrogen input pipe is provided with an inlet adjusting valve, the storage tank main pipe is connected with the hydrogen conveying pipe, the hydrogen storage tanks are connected with the storage tank main pipe through storage tank sub-pipes, and the storage tank main pipe is provided with an outlet adjusting valve and a hydrogen storage output pressure sensor. The buffer capacity, the operation efficiency and the safety of the multi-storage-tank system are improved, full-automatic balance control between hydrogen production and hydrogen utilization is achieved, pressure fluctuation and energy consumption are effectively reduced, and stable hydrogen supply of the system is guaranteed.

The invention discloses an MO source system for chemical vapor deposition equipment, the MO source system comprises a pressure reducing valve, a Sorce-MFC, a Push-MFC, a pressure controller, a Line valve, an RUN valve, an extraction valve and a manual valve, the pressure reducing valve is used for controlling the gas inlet pressure of a single-path MO source system, the Sorce-MFC is used for controlling carrier gas flowing into a source bottle, the Push-MFC is used for further adding the carrier gas to dilute the carrier gas flowing out of the source bottle, and the pressure controller is used for controlling the gas inlet pressure of the single-path MO source system. And the pressure controller is used for controlling the pressure of the flowing-out gas. The MO source in the MOCVD system is independent and connected into the corresponding CVD equipment process environment, the use process of the MO source is greatly simplified, continuous supply, temperature control and precise regulation and control of the MO source are achieved, precise control over the flow and pressure of the MO source and carrier gas is achieved through the pressure reducing valve, the Sorce-MFC and the Push-MFC, and the service life of the MO source is prolonged. Therefore, stable supply and uniform distribution of the MO source in the CVD equipment are ensured, and the production efficiency and the product quality of the CVD equipment are improved.

The embodiment of the invention provides a refrigerant supplement control method and device, refrigeration equipment and a computer readable storage medium. The refrigeration equipment comprises a refrigeration circulation system and a refrigerant supplement device. The refrigerant supplement control method comprises the steps that the outdoor environment temperature and the compressor frequency, the condenser outlet pressure and the evaporator inlet pressure of the refrigeration cycle system are obtained; according to the outdoor environment temperature, the compressor frequency, the condenser outlet pressure and the evaporator inlet pressure, the pressure deviation between the actual pressure and the target pressure of the refrigeration cycle system is calculated; and when the duration time when the absolute value of the pressure deviation between the actual pressure and the target pressure is larger than a pressure deviation threshold value reaches first preset time, the refrigerant supplementing device is controlled to supplement refrigerants to the refrigeration circulation system.

The invention discloses a centrifugal CO2 compressor unit frequency conversion-surge prevention cooperative control system and method based on fuzzy PID. The centrifugal CO2 compressor unit frequency conversion-surge prevention cooperative control system comprises an inlet mother pipe, an outlet mother pipe, a compressor C, a frequency converter VFD, a measuring unit, a frequency conversion control unit SICU, an anti-surge valve control unit ASVCU, an anti-surge protection control unit ASCU, an anti-surge bypass and an anti-surge valve ASV. The action weights of the frequency conversion valve and the anti-surge valve are dynamically distributed through the fuzzy rule, surge can be avoided, backflow loss can be reduced, the problem of mutual coupling of the two control systems can be solved, and the inlet pressure of the compressor unit is stabilized near a set value on the premise that the safety of the unit is guaranteed.

The invention discloses a gas compressor test device and method, and belongs to the field of gas compressor tests.The gas compressor test device comprises a driver, and a driving shaft of the driver is used for being connected with a main shaft of a gas compressor; the unloading assembly comprises a balance drum, a high-pressure gas supply unit, an exhaust unit and an adjusting valve, the balance drum is used for being connected with a main shaft of the gas compressor and used for being connected with an impeller on the main shaft of the gas compressor, the high-pressure gas supply unit is used for being communicated between the balance drum and the impeller, and the exhaust unit is used for being communicated with the side, away from the impeller, of the balance drum; an inlet temperature sensor, an inlet pressure sensor and a flow sensor are arranged in the double-twisted-wire air inlet channel; an outlet temperature sensor and an outlet pressure sensor are arranged in the annular outlet throttler; and a controller. The technical effects of the invention lie in that the device not only facilitates the independent test of the related gas compressor, but also facilitates the small axial force of the impeller of the gas compressor borne by the thrust bearing.

The invention discloses an automobile engine multi-mode electronic control system and a control method thereof, and particularly relates to the technical field of automobile engine multi-mode electronic control, the system comprises a sensor module, a mode switching module, an execution control module and a diagnosis module, the sensor module collects parameters such as rotating speed and air inlet pressure in real time; the mode switching module judges four working conditions of idling, cruising, accelerating and pressurizing based on threshold logic; the execution control module calls strategies such as PID (Proportion Integration Differentiation) control and EGR (Exhaust Gas Recirculation) rate calculation aiming at different modes to realize accurate adjustment of parameters such as throttle opening and boost pressure; the diagnosis module monitors faults of the sensor and the actuator in real time through voltage out-of-limit detection, position deviation comparison and temperature correlation analysis.

The invention discloses an adjustable buffer type inclined check valve, and relates to the technical field of check valves, when a medium flows in from an inlet end, close to one side of a protective appliance, of a valve body, pressure can jack up a connecting frame body to mount a valve pin shaft, the valve pin shaft drives a valve clack and the valve pin shaft to rotate upwards to open, a flow channel is completely smooth, and the medium passes through smoothly; when the inlet pressure is reduced or the outlet pressure is higher than the inlet pressure and has a backflow trend, the reverse pressure and the dead weight of the valve clack enable the valve clack to rapidly rotate downwards and be tightly attached to the valve seat block, sealing is formed, backflow is thoroughly blocked, a medium is prevented from being poured back to the upstream, and one-way flowing is stably kept. The fixing frame is matched with the valve seat block for inclined installation, the sealing effect between the valve seat block and the inner wall of the valve body is kept, an inclined installation structure is adopted, the opening and closing angle of the valve clack is small, the closing stroke is short, valve closing is faster, the sealing face is arranged in an inclined mode, the medium flow state is smoother, scouring is small, and sealing stress is even.

Mass flow control (MFC) devices capable of reporting inlet pressure and methods of reporting inlet pressure are provided. A mass flow controller (MFC) includes a chamber configured to receive a fluid, an upstream valve disposed upstream of the chamber, and a downstream control valve disposed downstream of the chamber. The MFC further includes a pressure sensor that detects fluid pressure in the chamber. The MFC further includes a controller configured to control actuation of the upstream valve. The controller is configured to toggle between two modes of reporting a measured inlet pressure. In a first mode, the controller reports a measured inlet pressure based on a reading from the pressure sensor and storing the reading to a buffer when the upstream valve is open. In a second mode, the controller reports the measured inlet pressure based on the reading stored to the buffer when the upstream valve is closed.