1818 results about "Bypass valve" patented technology

The invention relates to the technical field of fault diagnosis of industrial cooling equipment, and discloses a fault diagnosis early warning method and system for double bypass valves of an industrial cooler. According to the method, a state feature vector is constructed by obtaining real-time operation parameters, dynamic time sequence analysis is carried out on the state feature vector to calculate a sliding entropy value and a Lyapunov index, state evolution trend features are determined, a fault feature index is calculated in combination with the valve opening degree and a control signal deviation value, and an early warning threshold value is determined based on historical data distribution variance. And when the index exceeds a threshold value, determining a fault type and outputting early warning information. The potential fault of the bypass valve can be predicted in advance, the false alarm rate is reduced, and the diagnosis precision is improved.

The invention discloses a control method and device for a supercritical carbon dioxide recompression cycle power generation system, and the method comprises the steps: predicting the load change of the supercritical carbon dioxide Brayton cycle power generation system according to the historical operation data and current operation state of the supercritical carbon dioxide Brayton cycle power generation system; predicting the surge risk of the compressor according to the load change of the supercritical carbon dioxide Brayton cycle power generation system; according to the load change of the supercritical carbon dioxide Brayton cycle power generation system, the split ratio is adjusted, so that the recompression Brayton cycle power generation system operates at the optimal efficiency; and the flow, pressure and temperature of a compressor working medium in the supercritical carbon dioxide Brayton cycle power generation system are adjusted according to the surge risk, so that the compressor works in a non-surge area. When the supercritical carbon dioxide Brayton cycle power generation system approaches the surge boundary, the system adjusts the opening degree of the bypass valve in advance for flow release, so that active closed-loop control of surge prediction-response-relief is achieved, a compressor is effectively prevented from entering an unstable area under sudden load change, start and stop or extreme disturbance, and the service life of the compressor is prolonged. And the safety stability and the operation continuity of the system are obviously improved.

The invention relates to a paraffin type thermostat. The paraffin type thermostat comprises a main valve 1, a cover and seal gasket assembly 2, an upper support 3, a rubber pipe 4, a valve seat 5, a vent hole 6, a lower support 7, paraffin 8, an inductor 9, a bypass valve 10, a central rod 11 and a spring 12. The upper support, the lower support and the valve seat of the thermostat are riveted into a whole. The upper end of the central rod is fixed to the center of the upper support. The lower portion of the central rod is inserted into a central hole of the rubber pipe. The lower end of the central rod is conical. A cavity between the rubber pipe and a shell of the inductor contains the paraffin. The upper portion and the lower portion of the shell of the inductor are provided with the main valve and the bypass valve which are in linkage. The vent hole is formed in the main valve. The paraffin type thermostat is high in heat conductivity and guarantees that an engine cannot be excessively cold.

The invention provides a fuel cell vehicle heat management system and a control method thereof, and the system comprises a fuel cell circulating water path, a fuel cell cathode system and an air conditioner refrigerating and heating loop, an electric pile, an electronic temperature control valve, a first radiator fan assembly, a second electronic three-way valve, a first plate heat exchanger, a first electronic three-way valve and an electric pile water pump are sequentially arranged on the fuel cell circulating water path, and a deionizer and a first PTC heater are arranged on a pipeline between a water outlet of the electric pile water pump and a water outlet of the electric pile in series; a communicating pipeline is arranged between an upper water outlet of the electronic temperature control valve and a water outlet of the first electronic three-way valve; the fuel cell circulating water path exchanges heat with an air conditioner refrigerating and heating loop through a first plate heat exchanger; the fuel cell cathode system comprises an air compressor, an intercooler, a back pressure valve and a bypass valve. The waste heat of the air compressor can be fully utilized, the energy utilization rate is increased, the system structure is simplified, and the energy consumption of the vehicle is reduced.

Systems and generating power in an organic Rankine cycle (ORC) operation to supply electrical power. In embodiments, an inlet temperature of a flow of gas from a source to an ORC unit may be determined. The source may connect to a main pipeline. The main pipeline may connect to a supply pipeline. The supply pipeline may connect to the ORC unit thereby to allow gas to flow from the source to the ORC unit. Heat from the flow of gas may cause the ORC unit to generate electrical power. The outlet temperature of the flow of the gas from the ORC unit to a return pipe may be determined. A bypass valve, positioned on a bypass pipeline connecting the supply pipeline to the return pipeline, may be adjusted to a position sufficient to maintain temperature of the flow of gas above a threshold based on the inlet and outlet temperature.

The present invention discloses an improved structure of an oil channel of an oil filter base assembly in a vehicle, including an oil filter base, where a lower portion of the oil filter base is provided with an oil inlet, an oil outlet, and an oil return port, an end portion of the oil filter base is provided with an antifreeze solution water inlet, a bottom portion is provided with a first water outlet and a second water outlet that are communicated with the antifreeze solution water inlet, a filter cartridge and a bypass valve are mounted in one end of the oil filter base, a filter cover is connected to an end portion of one end, close to the bypass valve, of the oil filter base, an oil cooler is mounted on an upper portion of one end, away from the filter cartridge, of the oil filter base.

The invention provides a refrigeration house multi-fan intelligent cooperative defrosting control system and method. The refrigeration house multi-fan intelligent cooperative defrosting control system comprises an air-cooled condenser, a throttling valve, a compressor, a refrigerating chamber, a bypass valve, an air speed sensor, a temperature and humidity sensor, a temperature sensor, a pressure sensor, a flow meter, an air cooler tail end evaporator, data acquisition equipment, a central processing unit and a control output port. According to the cold storage scene that hot gas bypass defrosting is adopted, and one refrigerating unit is provided with a plurality of air coolers, the ratio (COP) of the accumulated refrigerating capacity to the total energy consumption in the operation period of each air cooler is calculated. And a comprehensive performance coefficient dynamic model of the air cooler is constructed by combining the temperature difference between the air supply and the air return, so that optimal energy efficiency of the air cooler and multi-fan defrosting control are realized. Compared with the prior art, the defrosting control logic is reconstructed from the perspective of the performance coefficient of the air cooler, the frosting condition of the surface of the evaporator at the tail end of the multiple fans of the refrigeration house can be accurately judged, it is ensured that the unit maintains high efficiency in the operation process, and development of the efficient and energy-saving control technology of a refrigeration house refrigerating system is facilitated.

The invention relates to the technical field of engine oil filters, in particular to a multistage filtering engine oil filter which comprises a shell, a filter paper frame is coaxially arranged in the shell, the surface of the filter paper frame is coaxially sleeved with a rough filtering inner sleeve, and the surface of the rough filtering inner sleeve is movably sleeved with a rough filtering outer sleeve capable of moving up and down. First filter holes for rough filtration are uniformly distributed in the surfaces of the rough filtration inner sleeve and the rough filtration outer sleeve, the rough filtration outer sleeve moves up and down to enable the first filter holes in the rough filtration outer sleeve and the first filter holes in the rough filtration inner sleeve to be in a staggered closed state, a lower opening is formed in the lower end of the shell, and a collecting cover is coaxially mounted at the lower end of the shell; the invention aims to solve the problem that after the bypass valve of the engine oil filter is opened, impurities attached to filter paper are easily separated from the filter paper and flow to the positions of all oil-consuming parts of an engine through the bypass valve along with engine oil.

The invention discloses a heat pump water heater low-temperature freezing oil return control method and system based on dynamic operation parameter adjustment, and the method comprises the following steps: monitoring the evaporator outlet refrigerant temperature, the compressor air return port temperature and the environment temperature in real time through a sensor, and calculating the temperature difference as a core control parameter; the opening degree of an electronic expansion valve and the rotating speed of a fan are dynamically adjusted through a fuzzy control algorithm in combination with the environment temperature and the compressor running frequency, and the low-temperature oil return stability of the system is maintained; when the core temperature difference exceeds a set threshold value, an oil return compensation mode is triggered, and the circulating fluidity of lubricating oil is enhanced by improving the frequency of a compressor and adjusting the opening degree of a bypass valve of a condenser; in the oil return compensation process, closed-loop adjustment is conducted on the exhaust temperature of the compressor through a PID control algorithm, and the operation safety of the system is ensured. The operating parameters are dynamically adjusted, the parameters such as the environment temperature and the system load are monitored in real time, and the control parameters are dynamically adjusted according to the parameters, so that the oil return requirements under different working conditions are met.

Embodiments of the invention provide a high density liquid cooling system including a rack, primary loop piping including a primary inlet, a primary outlet, a primary loop filter, and a primary bypass valve, and secondary loop piping including a secondary inlet, a secondary outlet, a first pump, a first filter downstream of the first pump, and a secondary bypass valve. The system includes a heat exchanger having a first side and a second side. When the primary bypass valve is open, at least a portion of the fluid in the primary loop piping flows through the primary inlet and the primary outlet without traversing the heat exchanger, and when the secondary bypass valve is open, at least a portion of the fluid in the secondary loop piping flows through the secondary inlet and the secondary outlet without traversing the heat exchanger.

The invention discloses a compressor unit of a compressor station, a control method of the compressor unit, a medium and a program product, relates to the technical field of compressors, and aims to solve the problem of resource waste during test dragging of the compressor unit of the compressor station. The compressor unit of the compressor station comprises a compressor; an inlet valve; an outlet valve; one end of the inlet bypass pipeline is connected to one side of the inlet valve, and the other end of the inlet bypass pipeline is connected to the other side of the inlet valve; an inlet bypass valve is arranged on the inlet bypass pipeline; after the purging operation included in the warm-up mode is executed, the inlet bypass valve is controlled to be opened, the inlet valve is controlled to be closed, and the outlet valve is controlled to be closed, so that the compression pipeline is inflated through the inlet bypass valve; the compression pipeline is a pipeline between the inlet valve and the outlet valve; under the condition that the pressure of the compression pipeline reaches a first set pressure value, the warm-up operation included in the warm-up mode is executed; the first set pressure value is lower than a second set pressure value corresponding to the compression pipeline in the starting mode.

The invention relates to a bypass flow control method and device, a fuel cell air system and a vehicle, and relates to the technical field of batteries, and the method comprises the following steps: under the condition that an air compressor of the fuel cell air system is in a surge working condition, determining a bypass flow request value based on the surge control flow and in-pile flow of the air compressor; the surge control flow is the minimum flow threshold value of safe operation of the air compressor; determining an opening degree feed-forward value of a bypass valve of the fuel cell air system based on the bypass flow rate request value; and the opening degree of the bypass valve is controlled based on the opening degree feed-forward value so as to control the bypass flow of the fuel cell air system, and therefore the opening degree feed-forward value is used for predicting the opening degree needed by the bypass valve according to the bypass flow request value, and opening degree adjustment of the bypass valve can quickly respond to changes of the surge working condition of the air compressor. And the bypass flow can be quickly adjusted through the opening feedforward value, so that the air compressor can quickly recover stable operation.

A turbo engine for an aircraft includes a gas turbine engine having a fuel system to provide fuel to a combustion section. The fuel system includes a variable displacement pump driven by an accessory gearbox that is powered by a shaft of the gas turbine engine. The variable displacement pump has an inlet side and an outlet side. The variable displacement pump includes an actuator configured to adjust a discharge flow rate of the variable displacement pump. The fuel system also includes a fuel metering valve configured to receive pressurized fuel from the variable displacement pump and control a flow rate of the pressurized fuel to the combustion section. The fuel system further includes a bypass valve fluidly coupling the outlet side and the inlet side of the variable displacement pump to direct an excess portion of the pressurized fuel at the outlet side back to the inlet side.

The invention relates to the technical field of denitration, and discloses a preheating and control method, device and equipment for activated carbon in an adsorption tower bin. The method comprises the following steps: calculating first heat of activated carbon in a stock bin, second heat brought by flue gas entering the stock bin, third heat released by denitration reaction in an adsorption tower, and fourth heat brought by original flue gas entering a denitration area of the adsorption tower; calculating a first temperature when the active carbon in the stock bin enters the adsorption tower and a second temperature of the active carbon in the denitration area according to the four heat quantities; and the first temperature and the second temperature are judged, and the flow of the smoke entering the stock bin is controlled according to the judgment result. The flue gas preheats the activated carbon in the stock bin through the bypass flue, the purified flue gas is reasonably utilized for preheating, the opening degree of the bypass valve is regulated and controlled according to the first temperature and the second temperature so as to regulate the flow of the flue gas entering the stock bin, the temperature of the activated carbon entering an adsorption area is stabilized in a proper temperature interval of denitration reaction, the denitration effect and efficiency are improved, and the energy consumption is reduced. Meanwhile, the safety of the denitration and desulfurization system is ensured.

The embodiment of the utility model discloses a circulating water variable-flow energy-saving system based on resistance coefficient optimization. The circulating water variable-flow energy-saving system comprises a variable-flow energy-saving control system, cold and heat source equipment, end equipment, a bypass regulating valve, a circulating water pump, a frequency converter connected with the circulating water pump, a differential pressure sensor, a flow meter, a water supply temperature sensor and a return water temperature sensor. The embodiment provided by the utility model has the beneficial effects that the resistance coefficient and the pressure difference set value are dynamically adjusted according to the flow and the temperature difference change in the operation process, the pressure difference of the system is optimized in real time, the supply and demand consistency of the operation of the system is ensured, and the energy consumption is reduced; the circulating water flow is controlled through variable flow regulation, the reaction is sensitive, and the adverse effect of hysteresis of conventional temperature difference regulation is eliminated; and the comfort of the user and the energy-saving performance of the system are both considered.

The present invention discloses a filter for dusty oil and gas, comprising a cylinder, the top of which is connected to a top cover, the bottom of which is connected to a cone, a first bypass port and a second bypass port are provided on the top cover and the cylinder, the two are connected through a pipeline to form an external passage, and a bypass valve is provided on the pipeline; a plurality of filter elements are provided in the cylinder; a first heating component and a second heating component are provided on the outer wall of the cylinder and the cone. The filter of the present invention, under the joint action of the heating component and the external passage, can not only ensure that the interior of the cylinder and the cone always maintains a relatively high temperature, but also can timely dredge the filter element during operation, thereby achieving effective separation of dust and oil and gas, and effectively avoiding abnormal phenomena such as negative pressure inside the filter, having the advantages of high processing efficiency, good filtering effect, low maintenance cost, high safety, long service life, etc., can effectively remove dust in the oil and gas when used for filtering dusty oil and gas, has high use value, and good application prospects.

A turbine engine for an aircraft includes a gas turbine engine having a fuel system that provides fuel to a combustion section. The fuel system includes a variable displacement pump driven by an accessory gearbox powered by a shaft of a gas turbine engine. The variable displacement pump has an inlet side and an outlet side. The variable displacement pump includes an actuator configured to adjust a discharge flow rate of the variable displacement pump. The fuel system also includes a fuel metering valve configured to receive the pressurized fuel from the variable displacement pump and control a flow rate of the pressurized fuel to the combustion section. The fuel system further includes a bypass valve fluidly coupling the outlet side and the inlet side of the variable displacement pump to direct excess of the pressurized fuel at the outlet side back to the inlet side.

The invention provides an in-cylinder braking power control method and device, a diesel engine and a diesel locomotive, and relates to the technical field of engines. The in-cylinder braking power control method comprises the steps that an activation result is obtained; when the activation result indicates that the in-cylinder braking function of the diesel engine is activated, the initial opening degrees of a supercharger bypass valve and an air inlet throttle valve and the initial inter-cooling post-pressure jointly corresponding to the initial opening degrees of the supercharger bypass valve and the air inlet throttle valve are obtained according to rack calibration data of the diesel engine; and when the initial post-intercooling pressure is not equal to the preset expected post-intercooling pressure, the initial opening degree of the supercharger bypass valve and / or the air inlet throttling valve is adjusted in a closed-loop mode, and the respective corrected opening degrees of the supercharger bypass valve and the air inlet throttling valve are obtained till first corrected post-intercooling pressure jointly corresponding to the respective corrected opening degrees is equal to the expected post-intercooling pressure. The problem that a diesel engine breaks down or is damaged or scrapped due to the fact that the braking power is not adjustable in the braking process in the existing in-cylinder braking technology can be solved.

A method for optimizing a flow of water of a swimming pool or spa includes monitoring a parameter associated with performance of a first piece of equipment of the swimming pool or spa, such as but not limited to a heat pump, and relative to a target for the parameter. The method includes activating a bypass valve such that water bypasses the first piece equipment based on the parameter reaching or exceeding the target. The method includes controlling operation of a second piece of equipment of a circulation system responsive to activation of the bypass valve.

A device for orienting core samples relative to their position in the subsoil before extraction, attaching to a core bit during drilling features a robust tubular body with a detector to identify core sample breakage and orientation using triaxial accelerometers and gyroscopes, measuring orientation by the gravity vector or true north. An electronic control unit stores, timestamps, and transmits data wirelessly via BLUETOOTH®, ensuring data reliability without removing the device. The device includes adapters for different pipe diameters, minimizing the need for disassembly and reducing user fatigue, while maintaining pump functionality with a bypass valve if needed

The invention relates to the field of fuel cell engines, in particular to a fuel cell bypass flow determining method and device, a storage medium and a vehicle, and the method comprises the steps that state data of a bypass valve of a fuel cell are collected, and the state data comprise the opening degree, the temperature and the pressure of the bypass valve; inputting the opening degree and the pressure of the bypass valve into the neural network prediction model to obtain the predicted standard condition flow of the bypass valve; the neural network prediction model is obtained based on historical sample data training of the bypass valve; calculating a correction factor according to the temperature and the pressure of the bypass valve; and according to the standard condition flow of the bypass valve and the correction factor, a fuel cell bypass flow predicted value is obtained through calculation. Through the combination of the neural network model and the correction factor, the precision, efficiency and cost are considered, and the limitations of the traditional MAP method in the aspects of precision, memory, data utilization and the like are solved.

A device for generating electricity in an irrigation system includes a water turbine, a generator, and a bypass valve. The water turbine converts the flow of water in the irrigation system into rotational energy. The generator is connected to the water turbine for converting the rotational energy into electrical energy. The bypass valve assembly is in fluid communication with the water turbine and the irrigation system and is configured to regulate the flow of water through the water turbine and to direct excess water around the water turbine and back into the irrigation system. The device is configured to generate electricity while maintaining a predetermined flow rate in the irrigation system and to direct excess water around the water turbine and back into the irrigation system when the flow of water through the water turbine exceeds the predetermined flow rate.

A refrigeration system includes a compressor, a condenser, a heat transfer component, and a refrigerant loop arranged to allow a flow of a refrigerant fluid. The compressor, the condenser, and the heat transfer component are connected in the refrigerant loop. The system further includes a bypass path extending between an output side of the compressor in the refrigerant loop and an input side of the heat transfer component in the refrigerant loop. A bypass valve is connected in the bypass path. A control circuit is in communication with the bypass valve. The control circuit is configured to open the bypass valve to allow the refrigerant fluid to pass to the heat transfer component thereby increasing the refrigerant fluid provided to the heat transfer component and artificially increasing a load on the refrigeration system. Other examples refrigeration system and examples methods are also disclosed.

The utility model belongs to the technical field of water heaters, and particularly discloses a gas water heater which comprises a water inlet pipe, a heat exchanger and a water outlet pipe which are sequentially communicated in the water flow direction, and further comprises a water mixing tank and a bypass pipe, the water mixing tank is arranged on the water outlet pipe, and a water inlet, a bypass water inlet and a water outlet are formed in the water mixing tank. The water inlet is used for being communicated with the water outlet end of the heat exchanger, the water outlet is communicated with the water using end through the water outlet pipe, the two ends of the bypass pipe are communicated with the bypass water inlet and the water inlet pipe respectively, a bypass valve used for adjusting the water flow is arranged on the bypass pipe, and the vertical distance H1 between the bypass water inlet and the water inlet is larger than the vertical distance H2 between the bypass water inlet and the water outlet. According to the gas water heater disclosed by the utility model, on the basis of solving the problem of water stop temperature rise during secondary starting, the outlet water temperature in the water stop temperature drop stage can be improved, and the structure of the water mixing tank is simplified while the water stop temperature drop is effectively improved.

The invention relates to an anti-surge control method for an energy storage heat management system of an air-floating centrifugal compressor. The anti-surge control method comprises the following steps: customizing surge state judgment conditions of the air-floating centrifugal compressor; determining the current surge state of the air flotation centrifugal compressor according to the surge state judgment condition, wherein the surge state comprises a normal working area, a surge protection area and a surge area; a corresponding control strategy is adopted according to the surge state of the air flotation centrifugal compressor, and if the air flotation centrifugal compressor is located in the surge area, the compressor is closed; if the air flotation centrifugal compressor is in the surge protection area, the grade of triggering surge is further determined, if the grade of triggering surge is the first grade, the rotating speed of the fan, the rotating speed of the air flotation centrifugal compressor and the opening degree of the auxiliary throttling element are adjusted, and if the grade of triggering surge is the second grade, the rotating speed of the fan is adjusted. If yes, the rotating speed of the fan and the rotating speed of the air flotation centrifugal compressor are increased to the maximum value, and if the surge triggering grade is the third grade, the bypass valve is opened.

The invention relates to the technical field of research of reactor material irradiation, and provides an irradiation and water chemical corrosion test system in a high-flux neutron environment, the irradiation and water chemical corrosion test system comprises a pressurizing unit, an in-reactor test device and a heat exchanger, the pressurizing unit comprises a first pressurizing pump, a second pressurizing pump and a first bypass valve which are arranged in parallel, a test sample is placed in the in-pile test device, the in-pile test device is placed in the neutron field, the heat exchanger is connected with a second bypass valve in parallel, the pipeline is hooped and sleeved with a heater, and through cooperation of the pressurization unit, the heater and the in-pile test device placed in the neutron field, a medium flowing in the pipeline is high-temperature and high-pressure water containing radioactivity; the in-reactor water environment can be simulated more accurately, material irradiation tests in high-temperature and high-pressure field, high-flux neutron field and radiation field environments are achieved, the reliability of test results is improved, and the temperature, flow and pressure of the system are flexibly adjusted by adjusting the opening degree of the first bypass valve and the opening degree of the second bypass valve.

The invention relates to a control method and equipment for an air system in the cold start process of a fuel cell, and relates to the field of fuel cells. In the cold start process of the fuel cell, the opening degree of the back pressure valve is set to be a fixed value, closed-loop control over the rotating speed of the air compressor and open-loop control over the opening degree of the bypass valve are conducted, and therefore the air flow control accuracy and stability of the fuel cell system are greatly improved. Besides, the starting temperature which is calculated only in the power-on initialization state and is not updated any more in the subsequent starting and running process is set, the target air pressure is corrected and calculated through the starting temperature to obtain a target air pressure correction value, and then the opening degree of the back pressure valve and the opening degree of the bypass valve are compensated and adjusted according to the correction value. Therefore, the system can reach the required optimal target air pressure during cold start in different low-temperature environments, so that the start adaptability and reliability of the fuel cell in different low-temperature environments are enhanced.

The invention discloses a transcritical carbon dioxide hot water system. The system comprises a first-stage compressor, a first heat exchanger used for exchanging heat with user side cooling water, a second-stage compressor, a second heat exchanger used for exchanging heat with user side cooling water, a third heat exchanger used for exchanging heat with a liquid-phase refrigerant and a gas-phase refrigerant, an expansion valve, a fourth heat exchanger used for exchanging heat with ambient air, a buffer water tank and a first proportional valve. A first proportional valve, a second proportional valve, a third proportional valve, a fourth proportional valve, a defrosting valve, a refrigerant path bypass valve and the like; according to the system, single-stage and double-stage compression switching in high-temperature weather and low-temperature weather can be achieved, it is guaranteed that the unit has good heating capacity and energy efficiency ratio when high-temperature water is discharged in the high-temperature weather and the low-temperature weather, and meanwhile the water outlet temperature control problem and the defrosting problem of the transcritical carbon dioxide single-double-unit compression system are solved.

The invention relates to the technical field of heat pump control, and discloses a defrosting method and device of a heat pump system and the heat pump system.The defrosting method comprises the steps that the temperature and humidity of gaps of a fin type heat exchanger are monitored in real time; and when the temperature is lower than or equal to the threshold value of the dynamic dew point temperature plus the safety margin and the humidity is higher than or equal to the threshold value, it is judged that the frosting prevention condition is met, the gap temperature is increased by adjusting the refrigerant bypass valve, the gap humidity is reduced by adjusting the airflow adjusting valve, and therefore frosting is actively prevented. And if the frost layer appears, short-time refrigeration interruption or low-power heating is started for defrosting according to the thickness of the frost layer or a pressure difference signal. And the formed ice layer is forcibly removed by switching the flow direction of the refrigerant and heating. By means of three-level linkage control, accurate defrosting in the whole process from prevention to removal is achieved, energy waste is effectively avoided, the defrosting efficiency and operation stability of the system are improved, and the user experience is improved.

The invention discloses a cooperative control method based on an air compressor and a bypass valve in a fuel cell load reduction process, and relates to the field of surge prevention of a fuel cell system, and the cooperative control method comprises the following steps: obtaining the air flow at an inlet of the air compressor, the rotating speed of the air compressor and the excess oxygen ratio; calculating the surge flow lower limit of the corresponding compressor based on the rotating speed of the air compressor; when the air flow of the inlet of the air compressor is lower than the multiple of the lower surge limit of the compressor, the bypass valve opening value a is increased to the initial bypass valve opening value to obtain an anti-surge opening value, and the rotating speed of the air compressor is synchronously increased to the first rotating speed; when the air flow at the inlet of the air compressor is higher than the surging lower limit of the compressor and the oxygen excess ratio is greater than or equal to the minimum peroxide ratio; the fuel cell stack inlet cathode pressure is obtained, and the bypass valve opening degree is controlled through PI based on the fuel cell stack inlet cathode pressure and the anti-surge opening degree value. According to the invention, combined anti-surge and anti-hypoxia control based on the air compressor and the bypass valve can be realized in the load reduction process of the fuel cell system.