1460 results about "Pressure difference" patented technology

The invention relates to the technical field of balance valves, and discloses a load compensation balance valve which comprises a balance valve body and an adjusting nut, a locking cap is in threaded connection with the outer arc surface of the adjusting nut, the right side of the locking cap is in contact with a main valve element spring, and the end, away from the locking cap, of the main valve element spring is in contact with a tip cone. The function of a one-way valve of one balance valve element assembly is canceled, so that oil inlet from a V port to a C port depends on the pressure of a control oil port and generates driving pressure through a throttling network composed of a specific throttling hole, the one-way valve and a bypass throttling hole, and the other balance valve element assembly obtains the driving pressure equal to the pressure of the control oil port through an independent throttling hole. A pressure difference is formed to realize sequential opening of the two assemblies; the linkage logic inhibits the jitter of the multiple feedback system under the negative load, stabilizes the falling speed of the arm support, and avoids the risk of overturning of the whole machine caused by the dynamic load.

The invention relates to the field of water quality monitoring, in particular to a water area environment water quality on-line intelligent monitoring device and method, and the water area environment water quality on-line intelligent monitoring device comprises a shell, a defoaming mechanism and a monitoring mechanism; a water inlet and a water outlet are formed in the shell, and a water flow channel is formed in the shell; a water inlet valve is mounted at the water inlet; the defoaming mechanism comprises a negative pressure cylinder arranged in the shell and a piston assembly arranged in the negative pressure cylinder; the piston assembly moves upwards to suck the water flow channel to negative pressure, bubbles in water flow are promoted to be separated out, the pressure difference between the two sides of the water inlet valve is increased, and the water flow is promoted to enter the water flow channel through the water inlet valve. The opening threshold value of the water inlet valve is adjusted according to the gas amount in the water flow, so that new water flow enters from the water inlet valve when the piston assembly sucks the water flow channel till the absolute value of the negative pressure is large enough, and the separation effect of bubbles in the original water flow and the new water flow in the water flow channel is guaranteed. And the water quality monitoring accuracy of the monitoring mechanism is improved.

The invention relates to the technical field of valves, in particular to a high-pressure-resistant quick opening and closing flat valve which comprises a valve body, a first valve seat, a second valve seat, a valve plate and a valve rod. The first valve seat and the second valve seat are arranged in a medium channel of the valve body, the valve plate is arranged between the first valve seat and the second valve seat in a sealing and sliding mode, and the valve rod is in driving connection with the valve plate. The middle of the valve rod is slidably connected to a valve deck in the middle of the top of the valve body, the hand wheel driving mechanism is connected to the upper portion of the valve deck, a pressure relief pipeline is arranged on the valve body, and the two ends of the pressure relief pipeline are communicated with a high-pressure side cavity, back to the valve plate, of the first valve seat and a low-pressure side cavity, back to the valve plate, of the second valve seat respectively. The pressure relief pipeline is provided with a pressure relief control valve used for controlling connection and disconnection of the pressure relief pipeline. The pressure difference generated by high-pressure fluid on the two sides of the valve plate can be balanced before the valve plate is opened, the main factor causing huge operation torque is fundamentally eliminated, opening and closing of the valve plate are extremely labor-saving and rapid, and rapid opening and closing under the high-pressure working condition are achieved.

The application relates to the technical field of well drilling, and is a motor control type variable-diameter stabilizer, which comprises a variable-diameter mechanism, a pressure driving mechanism, a non-magnetic drill collar, a control outer shell and a variable-diameter joint which are sequentially and threadedly connected together from top to bottom, the variable-diameter mechanism comprises a righting block which is slidingly installed in an installation sliding groove, the variable-diameter joint is provided with a limiting ring, a reset spring is arranged between the installation sliding block and the limiting ring, the variable-diameter joint is provided with a plurality of sinking grooves, a piston is arranged in each sinking groove, the variable-diameter joint is provided with a liquid storage channel, a communication hole which is in communication with the liquid storage channel is arranged on the inner side wall of each sinking groove, the control outer shell is internally provided with the pressure driving mechanism, the non-magnetic drill collar is internally provided with a control system, and the pressure driving mechanism is electrically connected with the control system. The application has the advantages of reasonable and compact structure, convenient use, safety, labor saving and high efficiency, and the righting block is controlled by forming a pressure difference at the variable-diameter joint and extending.

The invention discloses a design method of a pressure control throttle valve with the pressure drop linearly changing along with the stroke, and belongs to the technical field of automation of oil and gas exploitation equipment.The design method comprises the following steps that the linear relation between the pressure drop and the stroke of the throttle valve serves as a target; a mathematical model of a valve element contour is established by establishing a minimum throttling area equation of a cylindrical valve and a wedge-shaped valve, correcting a flow pressure drop characteristic equation and deducing a differential pressure linear adjustment equation, a valve element contour curve meeting the linear requirement is deduced through variable-diameter contour optimization design, and therefore the valve element structure of the throttling valve is obtained. By means of the design method, the valve element contour curve with the wider linearity range of pressure control adjustment and the better precision can be obtained, and the design method is more efficient and universal.

The invention provides a shale gas well inter-well pressure channeling identification method, system, device and medium, the shale gas well inter-well pressure channeling identification method comprises the following steps: carrying out well test analysis in a pump stop pressure drop stage after fracturing, and collecting data; the bottom hole pressure is calculated, and pressure data oscillation caused by the water hammer effect is eliminated; drawing a pressure difference and pressure difference derivative double logarithmic curve based on the bottom hole pressure data; establishing a shale gas well non-uniform fracture multi-zone coupling well test seepage model; the model parameters are adjusted, a pressure difference and pressure difference derivative double logarithmic curve is fitted, and when the model result is close to the drawn pressure difference and pressure difference derivative double logarithmic curve, the crack parameters of the model parameters are obtained through inversion; judging whether the crack parameter is too high or not; and determining the relationship between the child well group and the mother well group, analyzing the pressure difference and pressure difference derivative curve morphological characteristics of the fracture parameter high section, and judging whether pressure channeling occurs or not. The system can realize the method. According to the method, the inter-well pressure channeling identification efficiency in the well group synchronous fracturing period can be improved.

The invention relates to the technical field of air conditioners, in particular to an air conditioner control method and device, an air conditioner and a storage medium. According to the method, the communication state of the throttling element, the balance electromagnetic valve and the four-way valve in the air conditioner is adjusted by judging the operation mode before the air conditioner is shut down and the operation parameters before the compressor is shut down in combination with the outdoor environment temperature, so that the refrigerant pressure and the refrigerant flow direction in the refrigerant pipeline are controlled; the compressor is prevented from being pressed to rotate reversely due to the fact that the pressure difference value between the exhaust port and the air suction port of the compressor is too large, and the technical problem that in the prior art, an air conditioner stops under the condition that the pressure difference is large or the oil temperature is insufficient, and consequently the compressor rotates reversely is solved.

The invention relates to a hydraulic valve, particularly provides a hydraulic valve assembly, and aims to solve or relieve the problem of pressure difference between an oil inlet cavity and an oil outlet cavity of a hydraulic valve under a part of working conditions in the prior art. In order to achieve the purpose, the hydraulic valve assembly comprises a main valve body, a main valve element assembly, a control oil cylinder, a control piston and a guide assembly, and the main valve body comprises a main oil hole and a main valve element hole; the main valve element assembly is inserted into the main valve element hole, and the main valve element assembly and the main valve element hole form a valve line sealing structure. The control oil cylinder is positioned above the main valve body; the control piston is installed in the main valve element assembly and extends into the control oil cylinder together with the main valve element assembly. The guide assembly is arranged above the control oil cylinder and used for controlling the movement direction of the main valve element assembly to form different working states. All the parts are matched with one another so that external high-pressure oil can be used for pushing the control piston to open the main valve element assembly. Under the condition that the technical scheme is adopted, the residual pressure difference is eliminated through verification of a test bed.

The invention relates to the technical field of hydraulic control, and discloses a hydraulic motor constant torque self-adaptive PID (Proportion Integration Differentiation) control system which comprises a controller and a hydraulic driving unit, the controller performs frequency domain separation on the pressure signal by using a signal preprocessing module, and extracts an average pressure difference representing the driving force and a ripple amplitude representing the fluid rigidity; the state observation module estimates an instantaneous volume elastic modulus based on the ripple amplitude, corrects a compression item in a flow continuity model by using the elastic modulus, and calculates an instantaneous leakage coefficient of the motor in real time; the self-adaptive control module establishes dynamic mapping of PID gain and physical parameters, the proportional gain is adjusted by using a leakage coefficient to match system damping, the integral gain is adjusted by using a volume elastic modulus to adapt to inherent frequency, and a control instruction is synthesized by combining feedforward compensation. According to the method, the problem of model mismatch caused by oil characteristic change and motor abrasion is effectively solved, and the whole-life-cycle control precision of the system is improved.

The invention discloses a method and a device for controlling the flow rate of pressurized air flow of a bed layer of a pressure swing adsorption device, and relates to the technical field of adsorption control. The method and the device for controlling the flow rate of the pressurized air flow of the bed layer of the pressure swing adsorption device comprise the following steps: S1, acquiring pressure difference state data in real time, and preprocessing the pressure difference state data; s2, slip sheet displacement balance is carried out on the differential pressure state data; s3, throttling opening response is conducted on the pressure difference state data; s4, setting a movement boundary of the slip sheet; and S5, the pressure difference state data, the sliding vane displacement balance result and the throttling opening response result are synthesized to execute buffer energy consumption evaluation. The problems that the throttling opening is fixed, the gas flux cannot be dynamically adjusted according to the actual working condition and the adjusting rigidity and the energy efficiency are reduced due to the fact that the front and back pressure difference change of the adsorption tower cannot be sensed in real time in the throttling process and a pressure difference driven feedback adjusting mechanism is lacked are solved.

The invention discloses a numerical simulation method, system, equipment and medium for the complete closing process of a ball valve, and belongs to the technical field of valve control. The method comprises the steps that a geometric model of a ball valve pipeline is established, and pressure and speed monitoring points are arranged; carrying out particle discretization and relaxation on the valve pipeline geometric model through a meshless particle method discrete modeling technology; setting pressure inlet and outlet boundary conditions, and controlling a valve core to rotate so as to simulate the complete closing process of the valve from full opening to full closing; solving a transient closing process, and obtaining a pipeline velocity field and a pressure field under different opening degrees; the change rule of the inlet and outlet pressure difference, the flow coefficient and the flow resistance coefficient along with the opening degree is analyzed, and transient simulation of the ball valve closing process is achieved. According to the method, the problems of grid distortion and numerical instability are avoided through the meshless particle method, high-precision simulation of the complete closing process of the ball valve is achieved, the flow evolution mechanism in the closing process of the valve is revealed, and a theoretical basis is provided for analyzing the flow characteristics of the valve under the small opening degree.

The anti-collision adjustable buffering oil cylinder comprises a cylinder body, a piston rod is slidably connected into the cylinder body, a mounting base is fixedly mounted at the end of the cylinder body, a sealing sleeve is fixedly mounted on the side, away from the mounting base, of the cylinder body, and the end of the piston rod penetrates through the sealing sleeve; according to the technical scheme, through the inner buffering mechanisms at the two ends in the cylinder body, a buffering bearing ring, an inner buffering spring and an inner damper are used for cooperative buffering, rigid impact of the piston plate is avoided, the structure is protected, and the service life of the piston plate is prolonged. The problems of part damage, shortened service life and faults caused by too large pressure difference are solved, meanwhile, the outer buffering mechanism outside the cylinder body counteracts impact energy and blocks impurities through an outer anti-collision plate, an outer buffering spring and an outer damper, the position can be flexibly adjusted, the impact resistance and protection effect can be improved, and the problem that external protection is lacked is solved.

The invention provides a pneumatic driving part and a pneumatic valve, and relates to the technical field of valve control. The pneumatic driving piece comprises a front cover, a rear cover, a cavity and a piston piece; the first end of the cavity is connected with the front cover, the second end of the cavity is connected with the rear cover, the piston piece is arranged in the cavity, and the cavity is divided into a first inner cavity corresponding to the front cover and a second inner cavity corresponding to the rear cover based on a piston head of the piston piece; the piston piece is used for moving based on the pressure difference between the first inner cavity and the second inner cavity; the front cover is provided with a first one-way sealing piece, and the first one-way sealing piece is used for buffering the moving tail end, moving in the first direction, of the piston piece. The rear cover is provided with a second one-way sealing piece, and the second one-way sealing piece is used for buffering the moving tail end, moving in the second direction, of the piston piece. The first direction is the direction from the rear cover to the front cover, and the second direction is the direction from the front cover to the rear cover. And the movement tail ends of the piston piece in different directions can be buffered, and impact caused by inertia is effectively reduced.

The invention relates to the technical field of cone valve multi-mode air supply-energy dissipation cooperative cavitation reduction devices and control methods, and discloses a fluid control device named'cone valve multi-mode air supply-energy dissipation cooperative cavitation reduction devices and control methods'. The conical valve aims to solve the problems that an existing conical valve is serious in cavitation under the working condition of high pressure difference, air supply and energy dissipation functions are separated, and response lags. The device is characterized by comprising three stages of energy dissipation perforated pipes which are arranged at the outlet end of a valve body in a gradient mode, negative pressure injection air supply pipes which are symmetrically arranged outside a flow guide cover and flow guide fins which are welded to the inner wall of a cone, and the three stages of energy dissipation perforated pipes, the negative pressure injection air supply pipes and the flow guide fins cooperate to achieve pressure gradient pressure relief, self-adaptive air supply and flow state stability; the control method dynamically adjusts the air supply intensity based on the opening degree, the pressure difference and the vibration signal. According to the technical scheme, cavitation inception and collapse impact are remarkably restrained, vibration noise is reduced, the service life of the valve is prolonged, an external air source is not needed, the system pressure drop is controllable, and the system is suitable for ultrahigh pressure difference and large-flow hydroelectric working conditions.

The invention provides a valve device. The valve device comprises a main valve component, a bypass valve component and a communicating pipe. When the medium pressure difference of the inflow runner part and the outflow runner part of the main valve part reaches the preset value, the first valve port part of the bypass valve part can be opened for pressure relief, the bypass valve part and the main valve part are integrated, and the problem that the pressure relief function is lost due to reverse installation of the bypass valve part does not exist. The bypass valve component is provided with the pressure gauge connector part, the bypass valve component has a bypass function and a cut-off function, a channel between the pressure gauge connector part and the main valve component can be cut off, and the safety problem when the pressure gauge is connected is solved.

The invention belongs to the technical field of pipeline valves, and particularly relates to a resistance-free prevention valve. Comprising a discharge valve, a main valve and two check valves, and the two check valves are fixedly installed in an inner cavity of the main valve and divide the inner cavity of the main valve into an inlet cavity, a middle cavity and an outlet cavity. When the pressure difference between the inlet cavity and the middle cavity is larger than a set value, the discharge valve is closed, and when the pressure difference between the inlet cavity and the middle cavity is continuously smaller than the set value, the pressure difference discharge valve is opened, discharge and pressure reduction are conducted through the discharge channel, and the discharge valve is closed until the pressure difference between the inlet cavity and the middle cavity recovers to the set value; the anti-misoperation device is arranged in the discharge valve, so that misoperation discharge of the discharge valve caused by water pressure fluctuation in a pipeline can be effectively prevented, and water pressure loss is avoided; valve membrane abrasion is reduced, and the service life of the discharge valve is prolonged; and the pressure difference during drainage can be adjusted according to working conditions and requirements.

The utility model discloses an oil unloading tank for transferring crude oil, which comprises a tank body, two opposite ends of the tank body are respectively provided with an injection port and an output port, two layers of filter plates are fixedly connected inside the tank body, the inside of the tank body is divided into three parts by the filter plates, and the three parts are sequentially divided into a first cavity, a second cavity and a third cavity from the injection port to the output port. A sampling assembly is arranged on the outer wall, corresponding to the third cavity, of the box body, blow-down valves are arranged on the inner walls, corresponding to the first cavity and the second cavity, of the box body, and pressure assemblies are arranged on the outer walls of the first cavity and the third cavity. The pressure assembly is arranged in the oil unloading tank body, pressure distribution in the tank body can be changed, pressure difference is formed in the tank body, and crude oil is driven by pressure to penetrate through the filter screen, so that the filtering efficiency is improved.

The utility model provides a three-way valve which comprises a valve body provided with a valve cavity, a first connecting pipe and a second connecting pipe are arranged on the side wall of the valve body, and the first connecting pipe and the second connecting pipe are both communicated with the valve cavity; the valve element is movably arranged in the valve cavity and provided with a first sealing end and a second sealing end which are oppositely arranged, the first connecting pipe and the second connecting pipe are both located between the first sealing end and the second sealing end, the first sealing end is matched with the valve cavity to form a first cavity, the second sealing end is matched with the valve cavity to form a second cavity, and a plugging piece is arranged on the valve element. The plugging piece is used for plugging the first connecting pipe or the second connecting pipe; the pilot valve communicates with the valve cavity and is used for controlling the pressure difference between the first cavity and the second cavity so as to drive the valve element to move. According to the technical scheme, the problem that in the prior art, a three-way valve product is large in size and complex in structure, and consequently the manufacturing cost is increased can be solved.

A completion assembly includes a completion string and a valve assembly. The completion string is disposed within a wellbore. The valve assembly is coupled to a downhole end of the completion string and includes a housing, a sleeve, a compression spring, and a rotatable indexing assembly. The housing includes a first fluid port and a first shoulder. The housing defines, with a wall of the wellbore, an annulus. The sleeve is disposed within the housing and includes a second fluid port, an indexing slot, and a second shoulder. The valve assembly receives fluid from the completion string to increase a pressure of an inner volume of the valve assembly with respect to the annulus, generating a pressure differential causing the sleeve to axially move, moving the sleeve between an open position with the second fluid port open, and a closed position with the second fluid port closed.

The vibration absorption device comprises a shell and a buffer piston which are coaxially arranged, the buffer piston is sleeved with the shell, and the vibration absorption device further comprises at least two buffer cavities, an oil inlet way and a balance valve which are distributed on the periphery of the buffer piston at intervals in the axial direction; the oil inlet path is arranged on the shell and is communicated with at least one buffer cavity; the buffer cavities are communicated through the balance valves, the balance valves are used for changing the communication relation between the buffer cavities according to the pressure difference between the buffer cavities, the buffer cavities can be communicated in time, the buffer cavities needing oil supplementing are subjected to oil supplementing, sudden pressure drop of the cavities is avoided, and the phenomena of negative pressure and cavitation are avoided. Damage to parts in the rock drill is reduced, and the vibration absorption effect is improved. The second aspect provides a rock drill comprising the vibration absorption device in the first aspect, an impact piston coaxially arranged in the buffer piston in a sliding mode, a bit shank coaxially arranged on the front side of the impact piston, and a plug buffer spacer bush arranged on the impact piston in a sleeving mode and located between the buffer piston and the bit shank.

The invention relates to the technical field of steam feed pump monitoring, and discloses a steam feed pump running state monitoring method and system based on multi-parameter fusion. The method comprises the steps that multi-dimensional real-time parameters such as vibration amplitude, bearing temperature, inlet and outlet pressure difference, rotating speed fluctuation quantity and medium flow change rate in a continuous operation period are collected; according to the vibration amplitude time domain distribution and frequency domain energy ratio vibration anomaly grade, the temperature anomaly grade is determined by combining the bearing temperature rising slope, a pressure-rotating speed coupling coefficient is generated based on the coupling relation of the inlet and outlet pressure difference and the rotating speed fluctuation quantity, and the flow stability index is calculated through the deviation degree of the medium flow change rate and the historical reference flow. Integrating to generate a comprehensive degradation degree index; identifying steady state, transition state and critical state operation switching nodes according to the dynamic trend of the index; clustering grouping parameters, extracting state characterization parameters, and inputting a degradation prediction model to output a residual service life prediction value.

In order to solve the problem that the gravity of the existing moving automobile cannot be converted into the traction force of the automobile, the automobile gravity conversion device comprises hubs of symmetrical baffles which are connected on the circumferential cambered surface, and two semicircular inner tubes which are not communicated with each other in air pressure, and the two semicircular inner tubes are respectively communicated with an air cylinder; the two air cylinders are symmetrically and oppositely arranged and fixedly installed in the hub, pistons in the two air cylinders share a rack connecting rod and are meshed with a sector tooth swing rod with a rotating point fixedly installed on the hub, the sector tooth swing rod is hinged to a connecting rod, the connecting rod is hinged to an L-shaped rotating rod, the rotating point is assembled on the bottom face of the hub, the L-shaped rotating rod penetrates through the hub, and a gear is fixedly installed at the inner end of the L-shaped rotating rod. Therefore, the two half inner tubes alternately and indirectly touch the ground due to rotation to generate'air pressure difference ', and a piston in the cylinder reciprocates to be linked with a gear for transmission, so as to assist the running of an automobile in advance of the power of an engine.

The invention relates to the technical field of molten salt conveying, and discloses a molten salt spherical tank heat storage and heat exchange gas pressure conveying regulation and control system and method.The method comprises the following steps that multi-source parameters are read in real time, the current pressure difference is calculated to be combined with the temperature to fit the real-time viscosity value, the pressure difference, the viscosity and the valve opening degree are used for dynamically updating the theoretical calculation value of viscosity time lag, and the viscosity time lag is calculated. Historical data of time lag, pressure difference and valve opening are stored, a time window sample is formed, a time lag change rule is learned through an LSTM network, model weight parameters are updated online, a current working condition sequence is input, and a predicted value of future time lag is output. According to the method, the influence of fluid transmission time lag on pressure control is reduced, valve actions are synchronized with actual requirements through dynamic prediction and a fuzzy compensation mechanism, overshoot or undershoot of pressure is avoided, the anti-interference capability and robustness are enhanced by combining an online learning prediction model and a fuzzy inference rule base, and the pressure control precision is improved. And a scheme integrating dynamic response quality and long-term stable operation is realized.

The invention belongs to the technical field of refrigeration and heating equipment, and particularly relates to a reversing valve and an air conditioner heat pump system. Comprising a pressure driving assembly and a channel adjusting assembly. The channel adjusting assembly comprises a plurality of fluid channels, and each fluid channel comprises at least one fluid medium inlet and a fluid medium outlet; the fluid channels are separated by blocking elements; the pressure driving assembly comprises at least two cavities and a moving element used for blocking the two cavities, connectors serving as pressure driving channels are arranged in the two cavities respectively and used for generating pressure difference to drive the moving element to move, and the moving element is used for driving the blocking element to move so as to change the path of the fluid channel. According to the multi-way valve, the pressure difference serves as driving force, the valve element generates axial displacement or rotary motion, automatic switching of the working modes of the multi-way valve is achieved, and the working modes of a system are switched by switching the flow direction of fluid. And an automatic reversing function can be realized without extra electric energy or mechanical power input.

The invention relates to the technical field of petroleum and natural gas drilling engineering, and particularly discloses a multi-field coupled complex fractured formation fracture width distribution inversion method, which is characterized in that a drilling fluid leakage model considering a fluid-solid coupling effect is constructed based on a porous elastic mechanics theory, and a roughness correction factor is introduced to correct a traditional cubic law; the application of the Darcy law in the matrix is perfected, a matrix and crack coupled drilling fluid leakage mathematical model is established, the influence rule of key parameters such as fluid viscosity, pressure difference and crack width on the drilling fluid leakage amount is obtained through numerical simulation, and on the basis, the drilling fluid leakage amount is calculated. According to the method, the crack width multiple linear regression inversion equation with the fluid viscosity, the pressure difference and the accumulated leakage as independent variables is established, the inversion equation has high prediction precision and practicability and can be used for rapidly and accurately inversing the crack width on site, and theoretical and technical supports are provided for multi-scale fractured formation leakage mechanism understanding and leakage prevention and control optimization.

The invention relates to the technical field of fuel nozzle performance testing, in particular to an integrated high-precision fuel flow testing method and detection method.The testing method comprises the steps that a spraying test bed or a nozzle test bed is correspondingly selected based on whether a to-be-tested workpiece tests the spraying angle or not; after the integrated high-precision fuel oil flow testing device is in a reset state, a corresponding motor rotating speed is input to a digital control system based on the calibrated flow of the workpiece to be tested, a plunger pump of a high-pressure oil supply system is started, and oil liquid in an oil tank system is pumped to a corresponding spray test bed or nozzle test bed to run; the actual pressure difference of the workpiece to be measured is collected and transmitted to the digital control system, the actual pressure difference and the target pressure difference are compared, and the actual pressure difference is adjusted; when the preliminarily obtained actual oil flow is larger than a detection threshold value, the actual oil flow corresponding to the current flowmeter is defined as corresponding detection data; and when the preliminarily obtained actual oil flow is smaller than or equal to the detection threshold value, a weighing method is adopted for flow detection.

The invention provides a local resistance monitoring and valve opening control method for a heat accumulator, and belongs to the technical field of heat accumulating type combustion. The method comprises the following steps: operating a to-be-measured heat accumulator according to actual production and use time, and fitting the monthly average value of the pressure difference before and after the heat accumulator in each month with the use cumulative month under the condition of fixed air and gas flow to obtain a relation curve of the monthly average value of the pressure difference before and after the heat accumulator to be measured and the use cumulative month; obtaining a mapping relation between the local resistance coefficient increment of the to-be-measured heat accumulator and the monthly average value increment of the front and back pressure differences based on a fluid mechanics principle; calculating the monthly average value of the front and back pressure differences of the to-be-measured heat accumulator in the target month and the local resistance coefficient of the to-be-measured heat accumulator based on the relation curve; determining the monthly average value increment of the front and back pressure differences of the to-be-measured heat accumulator in the target month according to the mapping relation based on the local resistance coefficient of the to-be-measured heat accumulator; and determining a heat accumulator valve opening degree adjusting scheme according to the difference value between the monthly average value increment of the front and back pressure differences of the to-be-measured heat accumulator in the target month and the actual pressure difference.

The invention discloses an energy-saving coal-fired unit desulfurization slurry circulating pump control method and system.The desulfurization slurry circulating pump comprises a pump machine, a feeding pipe communicated with the feeding end of the pump machine and a filter pipe detachably connected to the feeding pipe, and the control method comprises the steps that the pressure difference between the inlet end and the outlet end of the filter pipe in the current control period is obtained, meanwhile, the outlet flow value of the pump machine is obtained; calculating a first pressure difference threshold value corresponding to the blockage degree of the filter pipe based on the outlet flow value; comparing the pressure difference with a first pressure difference threshold; and if the pressure difference is larger than a first pressure difference threshold value, it is judged that the filter pipe is blocked, a first early warning signal used for prompting maintenance is generated, the operation rotating speed of the pump machine in the next control period is increased, and the outlet flow value is adjusted to the preset flow interval in the next control period. By monitoring the pressure difference of the filter pipe and the flow of the pump in real time, the blockage state is dynamically judged, the rotating speed of the pump is automatically adjusted, the circulating flow of desulfurization slurry is guaranteed, and the maintainability and stability of a filter assembly are improved.

A pressure relief valve having an inlet port and an outlet port is disclosed for retaining pressure from an outlet until a set pressure is achieved at the inlet. The valve is disposed between the inlet and outlet ports and has a valve member movable between an open position that allows fluid flow between the ports and a closed position that prevents fluid flow. Inlet pressure acts on the valve member to increase its closing force. A movable sensing spindle is provided in fluid communication with the inlet pressure and a reference pressure, the sensing spindle having a first position and a second position. As the pressure difference between the inlet pressure and the reference pressure increases toward the set pressure, the sensing spindle moves, eventually acting on the valve member to move it away from its sealing position, thus providing an opening for fluid to flow from the inlet to the outlet.

The utility model relates to an EGR (Exhaust Gas Recirculation) valve body air tightness detection device which comprises a detection table, and a fixed seat, a driving assembly, a guide rail, an air inlet seat, a first air inlet pipe, a second air inlet pipe, a first flow meter, a second flow meter, a differential pressure gauge and a pressure gauge which are arranged on the detection table, the fixed seat is connected to the output end of the driving assembly, the fixed seat is arranged on the guide rail, and the driving assembly drives the fixed seat to move on the guide rail; the first air inlet pipe and the second air inlet pipe are respectively connected with the air inlet seat, the first flow meter is arranged on the first air inlet pipe, and the second flow meter is arranged on the second air inlet pipe; the fixing seat is further connected with an air outlet pipe, and the differential pressure gauge and the pressure gauge are arranged on the air outlet pipe. The EGR valve body air tightness detection device is simple in structure principle, and the EGR valve body air tightness detection is convenient.