768 results about "Differential pressure" patented technology

The invention discloses a pressure-controlled drainage gas production method and system for a coal-bed gas well. The pressure-controlled drainage gas production method comprises the steps that drainage is conducted through the first daily drainage amount, wherein the first daily drainage amount meets the eliminating demand for production interference objects in a coal bed; and a pressure-supplementing medium is injected while drainage is conducted, and the downhole flow pressure daily drop amount is maintained as a first differential pressure value so as to avoid retracting and closing of pores and cracks in the coal bed. According to the pressure-controlled drainage gas production method for the coal-bed gas well, the drainage speed at the drainage state can be conveniently determined, the eliminating demands for drilling and completion fluids, pulverized coal and slack coal in the coal bed can be met, and meanwhile, retracting and closing of the pores and the cracks in the coal bed can also be avoided; and compared with the prior art, the pressure-controlled drainage gas production method is simple in process, the production efficiency of the coal-bed gas well can be greatly improved, and quite high practical value and popularization value are achieved.

The invention discloses an intelligent gas micro-differential pressure monitoring system based on multi-sensor fusion, and relates to the technical field of gas micro-differential pressure monitoring, a sensor network arranged at a pipeline collects and verifies process state data, a component fluctuation index is established to quantify the fluctuation degree of gas components, and if the component fluctuation index is abnormal, the component fluctuation index is determined to be abnormal. Calling a dynamic physical property compensation function to output a correction coefficient and a differential pressure reference value; if the accumulative deviation between the actually measured differential pressure and the theoretical differential pressure reference value exceeds a set threshold value, locally adjusting and optimizing or globally re-calibrating and updating the model; outputting a real-time correction value and deviation measurement through a fusion algorithm, and when an error continuously exceeds the standard, dynamically adjusting a fusion weight or triggering model calibration; if the obtained value exceeds the preset threshold value, early warning or alarming is sent out and fed back to the previous step.

The invention discloses a flowmeter-oriented embedded multi-parameter fusion calibration control method and system, relates to the technical field of industrial measurement and embedded control, and is used for solving the problem of unstable calibration caused by misalignment of multi-link flow signals, compensation lag and fusion oscillation. The method relates to synchronous acquisition, pretreatment and calibration of differential pressure type, ultrasonic wave and thermal type mass measurement links and environment parameters such as temperature, pressure and density. All-channel unified time scales are established through ternary binding, filtering and denoising, zero snapshot and alignment rules, a stability scoring mechanism is constructed in combination with offset behavior recognition, event classification and feature aggregation, and dynamic switching of a compensation path and a fusion strategy is driven. In a double-path fusion structure, table look-up compensation, model estimation, multi-algorithm parallelism and fusion track recording are adopted, version traceability and calibration result closed-loop control are achieved, and the stability and rechecking performance of mass flow output under complex disturbance are effectively improved.

The invention belongs to the technical field of flowmeter verification, and discloses a two-phase flow analysis system and method based on a differential pressure flowmeter and an electromagnetic flowmeter. The method comprises the steps that a differential pressure flow meter and an electromagnetic flow meter are arranged on adjacent sections of a pipeline, the electromagnetic flow meter collects voltage signals and analyzes the voltage signals to obtain liquid phase volume flow, and liquid phase mass flow is obtained by combining temperature correction; the differential pressure flowmeter calculates the gas density by using an ideal gas law according to the temperature and the pressure; inputting multi-sensor time sequence data into the weight optimization model, and optimizing the volume gas content and the total mass flow rate; baseline parameters are calibrated during full-pipe single-phase flow to obtain zero drift, and real-time temperature and pressure dynamic correction are combined, so that the metering precision and the working condition adaptability are improved; the problem of verification deviation of a traditional flowmeter is solved, high precision and high reliability of complex gas-liquid two-phase flow metering are achieved, and efficient and reliable technical support is provided for two-phase flow precise metering and process control in the fields of chemical engineering, energy and the like.

The invention discloses a shell-and-tube heat exchanger abnormity diagnosis method based on multi-parameter monitoring. The method specifically comprises the following steps that 1, temperature values and pressure values of a shell-and-tube heat exchanger tube pass inlet, all-pass connecting positions and a tube pass outlet are collected; step 2, carrying out segmented pressure difference calculation based on the collected pressure values, verifying the total pressure difference, if a verification result exceeds an error range, carrying out pressure value collection and calculation again, and if the verification result is within the error range, carrying out step 3; 3, calculating the proportion of the differential pressure of each process in the total differential pressure, then carrying out dynamic threshold judgment, and carrying out flow fluctuation alarm or carrying out the step 4 according to a judgment result; and 4, performing temperature gradient calculation based on the acquired temperature value, and diagnosing the abnormal pressure difference position as blockage or leakage based on the temperature gradient. The problem that in the prior art, due to the fact that the detection parameter is single, the accuracy of the detection result is poor is solved.

The invention relates to the technical field of engineering machinery, and particularly discloses an electrically-driven metering pump load-sensitive system, a control method and engineering machinery, the electrically-driven metering pump load-sensitive system comprises a control unit, a driving motor assembly, a metering pump, a pilot hydraulic control unit, a pilot handle assembly, a load-sensitive valve assembly, an actuator assembly, a sensor assembly and a pressure difference control module; the driving motor drives the metering pump to supply oil to the load-sensitive valve assembly so as to drive the actuator assembly to operate; the control unit receives the maximum outlet pressure and the maximum load pressure of the pump collected by the pressure sensor, receives a system target pressure difference signal of the pressure difference control module at the same time, and synchronously controls the rotating speed of the motor and the valve target pressure difference output by the proportional pressure reducing valve. The system aims to solve the problems that a traditional upstream compensation load sensitive system lacks a flow saturation resisting function, and a downstream compensation load sensitive system has extra reversing energy consumption and fixed system pressure difference setting.

The invention discloses a fixed-point calibration and precision compensation method of a differential pressure type flowmeter and related equipment, and relates to the field of fluid measurement, and the method comprises the following steps: connecting the differential pressure type flowmeter to be calibrated and a standard flowmeter in series in the same gas path, and respectively collecting front-end pressure, front-back pressure difference of a laminar flow element and gas temperature; and a volume flow calculation model is established based on the structure parameters of the laminar flow element. Under the condition that a standard flowmeter outputs constant flow, fixed-point calibration is conducted on the flowmeter at a plurality of discrete temperature nodes and a plurality of discrete pressure nodes, a temperature compensation factor and a pressure compensation factor are determined respectively, and a continuous temperature compensation function and a continuous pressure compensation function are constructed through B-spline curve fitting. And substituting the compensation function into a volume flow calculation model to form a compensation volume flow model, and correcting the output of the differential pressure type flowmeter. And the influence of temperature change and pressure change on the flow characteristics and geometric characteristics of the laminar flow element can be effectively eliminated.

The invention provides a pressure difference bypass device for a water distributing and collecting device of a variable-flow liquid cooling system, and relates to the field of variable-flow liquid cooling systems, the pressure difference bypass device comprises a main water inlet collecting pipe, a water distributing device main body, a main input pipe and a connecting pipe, the main water inlet collecting pipe is communicated with the water segregator main body through the connecting pipe, and the main input pipe is connected with the main water inlet collecting pipe. On the basis of real-time data of the pressure difference detector and the backflow flow speed detector, the central control unit dynamically adjusts the opening degree of the intelligent flow speed adjusting valve through a PID algorithm, so that the flow of a main loop is accurately matched with the requirements of branches, and redundant energy consumption of a traditional constant flow system is eliminated. And a system health degree evaluation model is constructed, when the branch flow is lower than a preset safety threshold value, the stabilized pressure pump is triggered to be shut down for protection, and the cavitation risk is avoided.

The invention relates to the technical field of equipment compensation control, and discloses a medical suction device with an altitude compensation function and a control method thereof. The method comprises the following steps: reading ambient air pressure data of a first pressure sensor, reading molecular sieve tank differential pressure data of a second pressure sensor, collecting pressure data of an output end of a third pressure sensor, and determining a real-time altitude according to the ambient air pressure data; a breathing pressure fluctuation value is calculated based on the molecular sieve tank differential pressure data, when the breathing pressure fluctuation value is lower than a preset negative pressure threshold value, the current breathing frequency is recorded, and nitrogen removal time, pressure equalizing time and flushing time are determined to control an electromagnetic valve to work; and when the oxygen concentration is lower than a first concentration threshold value and the real-time altitude height is lower than a preset height, increasing the nitrogen removal time by a first preset proportion and increasing the target rotating speed by a second preset proportion, and when the oxygen concentration is lower than a second concentration threshold value, stopping the operation of the compressor and closing all the electromagnetic valves. According to the invention, the false alarm rate is effectively reduced, and the equipment safety is improved.

The invention relates to the technical field of sensor testing, in particular to monocrystalline silicon differential pressure sensor function verification testing equipment which comprises a communication switching mechanism, a low-pressure pipe and a high-pressure pipe, high-pressure input and low-pressure input can be accurately controlled by connecting the low-pressure pipe and the high-pressure pipe to different pressure sources respectively, the full-range testing requirement of a differential pressure sensor is met, and the testing efficiency is improved. Common pressure combinations such as high pressure and low pressure, low pressure and high pressure, double high pressure and double low pressure in an industrial field can be simulated through the communication switching mechanism, performance verification of the sensor in a real environment is ensured, and the problem that an existing testing device cannot simulate a real testing environment and a multi-working-condition testing scene is solved.

The invention relates to the technical field of sonar buoy detection, in particular to a multi-channel positive and negative pressure airtightness detection system which comprises an equipment cabinet, a high-pressure pump, a vacuum pump, a computer and a detected cabin. The equipment cabinet is provided with two ventilation air paths which are respectively connected with the high-pressure pump and the vacuum pump, the balance tank and the detected cabins are inflated or deflated by controlling valves in the air paths, and a differential pressure sensor is used for detecting the pressure difference value of the balance tank and the detected cabins to judge whether the balance tank and the detected cabins leak air or not. According to the invention, by outputting multiple detection channels, multiple detected cabins can be detected at the same time and independent detection results can be given, so that the detection efficiency is improved; the airtightness detection system is simple in composition structure, does not need additional high-pressure-resistant sealing tanks and tools, adopts the differential pressure type sensor to improve the test precision and accuracy, and is convenient to operate, safe and reliable.

The invention relates to the technical field of petroleum engineering, in particular to a device and method for testing migration of a proppant in a shale reservoir, and the device comprises a model system, an injection system, a vacuumizing system, a pressure field measurement system, a differential pressure measurement system, a back pressure system and a data acquisition and processing system. The model system comprises a model box, a test bin is arranged in the model box, and the test bin penetrates through the side wall of one side in the width extension direction of the model box; the pressing plate can completely cover the test bin and is detachably connected with the model box; the two fluid conveying assemblies are arranged at the two ends of the model box in the length extension direction respectively, the structures are in mirror symmetry, each fluid conveying assembly comprises a first connecting pipe, and the first connecting pipes are communicated with the testing bin. According to the device and the method, different-width fracture and netlike fracture forms of the shale reservoir can be simulated, and the migration rule of shale reservoir fracturing fluid carrying sand in the fractures can be analyzed.

The invention relates to the technical field of flow measurement, in particular to an integrated differential pressure type orifice plate flowmeter which comprises a differential pressure transmitter, a filtering structure, a driving structure, a mounting structure, a fixing structure, a dismounting structure, a three-valve set, a pressure guide pipe and a mounting pipe. The arrangement of the filtering structure is convenient for intercepting and filtering a medium in the fluid channel, impurities can be prevented from entering a subsequent detection assembly to influence the detection effect, interference on flow detection is prevented, the driving structure is convenient for driving the guide block to drive the filter screen to reciprocate, and the relative position of the filter screen and the impurities is continuously changed. A first screw rod in the mounting structure drives a connecting ring to drive a plurality of abutting blocks to abut against a pipeline flange plate at the same time, so that particle impurities are not prone to adhering to the surface of a filter screen, the blocking risk is reduced, it is ensured that fluid smoothly passes through the filter screen, and a hole plate can be rapidly replaced without disassembling a plurality of components through drawing and inserting type mounting in the mounting structure, and the replacement efficiency is improved. And the installation efficiency of the flowmeter installation pipe is improved.

The invention discloses a high-gas-liquid-ratio gas-liquid two-phase flow and liquid holdup measurement method and device based on three-dimensional differential pressure, and the method comprises the steps: applying a centrifugal force to a gas-liquid two-phase flow through a centrifuge, and generating a stable gas nucleus-liquid ring separation structure; measuring radial differential pressure, axial differential pressure, temperature and pressure values of the centrifuge in real time; establishing a liquid holdup calculation model based on the differential pressure ratio of the radial differential pressure and the axial differential pressure, and obtaining the liquid holdup according to the liquid holdup calculation model; calculating a friction coefficient and corrected gas phase density according to the temperature and pressure values; and based on the mapping relation between the axial differential pressure and the gas phase apparent velocity and the gas state equation, the gas-liquid two-phase flow is calculated according to the liquid holdup, the friction coefficient and the corrected gas phase density. According to the invention, a high-precision, separation-free and fast-response industrial-grade solution is realized, and a new-generation measuring tool is provided for the key fields of shale gas exploitation, submarine oil and gas pipeline transportation and the like.

The invention discloses a differential pressure sensor precision calibration method for high-temperature environment monitoring, and relates to the technical field of sensor calibration, and the method comprises the steps: carrying out the high-temperature factor extraction and simulation parameter design of the application scene information of a differential pressure sensor, and obtaining a high-temperature test parameter table of the sensor; a standard differential pressure source is arranged in the high-temperature environment controllable simulation chamber; acquiring a multi-high-temperature parameter differential pressure test data set of the standard differential pressure source; establishing a multi-high-temperature parameter differential pressure compensation model set; obtaining a high-temperature calibration coefficient differential pressure compensation model set; and performing calibration matching calibration on the application scene information of the differential pressure sensor to be calibrated to obtain a differential pressure sensor precision calibration result. The technical problem that the measurement precision and stability of the sensor are poor due to the fact that the measurement precision of the differential pressure sensor is difficult to effectively calibrate in the high-temperature environment in the existing differential pressure sensor precision calibration is solved, and the technical effects of improving the measurement precision of the differential pressure sensor and improving the measurement stability and reliability are achieved.

The invention relates to an inner cone type differential pressure flowmeter based on multi-parameter compensation. The flow meter aims to solve the technical problem that an existing flow meter is greatly influenced by fluid parameters. According to the technical scheme, the device comprises a constant flow unit, a testing module, a transmitter module and a data processing module, a temperature measuring element and an inner cone throttler are arranged on the upstream inner wall and the downstream inner wall of a measuring pipeline in the fluid direction, the transmitter module comprises a temperature transmitter, a pressure transmitter and a differential pressure transmitter, the temperature transmitter is electrically connected with the temperature measuring element, and the pressure transmitter is electrically connected with the differential pressure transmitter. The pressure transmitter is electrically connected with a pipeline, the differential pressure transmitter is electrically connected with the head end and the tail end of the inner cone throttler, the data processing module comprises an adder, a multiplier and a squarer, the temperature transmitter, the constant current unit and the pressure transmitter are connected with the adder, the adder and the differential pressure transmitter are connected with the multiplier, the multiplier is connected with the squarer, and the squarer is connected with the output unit. Errors caused by fluid physical property parameter changes can be eliminated to the maximum extent through measured values, and the measurement precision is greatly improved.

The utility model relates to the technical field of fluid measurement, in particular to a multi-stage adjustable throttling assembly and a flow measuring device. Comprising a measuring pipe, a piece, a rotating shaft and a rectifying piece, the surface of the measuring pipe is provided with at least two groups of high-pressure pressure taps and low-pressure pressure taps, throttling elements are rotatably arranged in the measuring pipe, the throttling amounts of the throttling elements are different, the throttling elements are arranged between the high-pressure pressure taps and the low-pressure pressure taps, and the rectifying piece is arranged between the high-pressure pressure taps and the low-pressure pressure taps. The rotating shaft is rotatably arranged in the measuring tube, the end part of the rotating shaft is connected to the throttling elements, and the rectifying part is arranged in the measuring tube and is positioned between the two groups of throttling elements. The two throttling elements with the continuous throttling ratio are arranged at intervals, the flow in a pipeline is obtained through conversion according to the differential pressure generated when fluid flows through the corresponding throttling elements, and the measuring range of a differential pressure sensor can be increased when the two throttling elements are used in cooperation with the differential pressure sensor.

The loop type natural gas secondary calibration system comprises a loop unit, a flow and pressure control unit, a temperature control unit, a leak detection unit and a control unit, and natural gas circulates in the loop unit; the flow and pressure control unit, the temperature control unit and the leak detection unit are electrically connected with the control unit; the flow and pressure control unit is used for stabilizing the flow and pressure of the natural gas in the loop unit; the temperature control unit is used for stabilizing the temperature of natural gas in the loop unit; the leak detection unit is used for detecting whether two ends of the detected flowmeter leak or not; the loop unit is further provided with a first electric ball valve, a differential pressure transmitter, a second temperature transmitter and a sonic nozzle standard meter. The calibration method comprises the steps of calibration operation preparation, calibration operation and leak detection operation. The system can simplify the natural gas verification and adjustment process, reduces the dependence on a natural gas transmission station, has the leakage detection capability, and is worthy of popularization and application.

The invention relates to a DDPF regeneration control method, system and program product based on a differential pressure transducer, when a vehicle is in a parking regeneration control state, an engine is controlled to increase the idle speed, and when the upstream temperature of the DDPF exceeds an ignition temperature limit value, the vehicle enters the parking regeneration state; during regeneration, the amount of fuel injected into the engine is determined according to the DDPF upstream temperature, the set temperature target value and the waste gas amount, and engine rear injection is controlled for DDPF regeneration; according to the method, the pressure difference between an inlet and an outlet of the DDPF is obtained, the peak pressure difference P of the DDPF is determined when the regeneration state continues till the pressure difference begins to drop, and the fuel injection quantity is corrected or a prompt signal is sent out according to the size relation between the P and a set limiting value. A temperature sensor at the rear end of the DDPF is omitted, the characteristic that the pressure difference is increased and then reduced due to oxidation heat release of carbon particles and hydrocarbon during regeneration is utilized, regeneration control is achieved based on a pressure difference sensor, and the risk of local overheating damage is dealt with by comparing a pressure difference peak value with a set limiting value.

The invention provides a mixed flow velocity and flow measuring device and method, and particularly relates to the technical field of measuring instruments, and the device comprises a gas mixing assembly, a flow field optimization assembly, a flow velocity sensing assembly and a signal processing assembly. The gas mixing assembly comprises a differential channel mixer and a mixing cavity, and gas premixing is achieved. The flow field optimization assembly comprises a plurality of air duct partition plates and straight pipe sections, and the mixed gas conveying pipeline is divided into a plurality of independent divided air ducts; the flow velocity sensing assembly comprises a rectification assembly and a pressure sensing assembly, the rectification assembly comprises a pore plate and / or a grid, and the pressure sensing assembly comprises a plurality of uniformly distributed pressure sensing elements; the signal processing assembly comprises a differential pressure sensing transmitter, a static pressure sensing transmitter, a temperature sensing transmitter, an atmospheric pressure sensing transmitter and a data processing module. The pressure sensing element detects differential pressure signals, the differential pressure sensing transmitter converts the signals, the data processing module calculates the average flow velocity and flow of the mixed gas based on the signals and measurement data, and the measurement precision and accuracy are improved.

This application relates to an isolated detection system and detection method for the liquid nitrogen liquid level height based on differential pressure calculation. By simulating and calculating the air pressure height difference between the liquid bottom and the liquid surface of the liquid nitrogen tank, a differential pressure signal between the return air pipe 3 and the gas measuring pipe is obtained, and the air pressure height difference between the liquid bottom and the liquid surface of the liquid nitrogen tank is calculated based on the pressure formula, so as to obtain the height position of the liquid nitrogen in the liquid nitrogen tank and perform liquid replenishment control. The differential pressure measurement system is completely isolated from the outside of the liquid nitrogen tank, eliminating the extremely harsh environment inside the tank and ensuring the long-term stable operation of the measurement equipment; the high-precision differential pressure measurement unit can accurately measure the liquid nitrogen height within the range of 1 millimeter, with high precision; only by inserting the gas measuring pipe to the lowest position of the liquid level, the detection of the corresponding range can be automatically matched without adding any circuit, and the measuring range is adjustable; it is suitable for the liquid level measurement of any sealed or unsealed tank or even a tankless situation, avoiding the short circuit of internal electronic equipment and being struck by lightning.

The invention relates to a method and a system for calculating air leakage of a three-section rotary air pre-heater. The method comprises the following steps: acquiring related data of primary air, secondary air and a flue gas bin; the air leakage amount of primary air and secondary air is calculated on line; wherein the air leakage amount of the primary air comprises the air leakage amount of the primary air leaking into the flue gas bin and the air leakage amount of the primary air leaking into the secondary air; the air leakage amount of the secondary air comprises the air leakage amount of the secondary air leaking into the flue gas bin; the average differential pressure among the primary air, the secondary air and the flue gas bin is calculated through a variable flow method; the average differential pressure corresponding to the primary air or the secondary air is changed, and the air leakage coefficient of the primary air leaking into the smoke bin, the air leakage coefficient of the primary air leaking into the secondary air and the air leakage coefficient of the secondary air leaking into the smoke bin are obtained; the temperature correction coefficients of the primary air and the secondary air are calculated through the temperature correction coefficients; the air leakage coefficient and the temperature correction coefficient are combined, and the corrected air leakage amount of the primary air leaking into the flue gas bin, the corrected air leakage amount of the primary air leaking into the secondary air and the corrected air leakage amount of the secondary air leaking into the flue gas bin are calculated.

The present application belongs to the field of smelting coal gas recovery, and particularly relates to an optimized control method and system for combustible gas recovery. The method divides the smelting process into N measurement time periods, and calculates the average secondary combustion coefficient of each time period in real time. Meanwhile, M target smelting time zones and their weights are set, and a dynamic target value sequence is established. Based on the initial fan speed, the measured coefficient is adjusted through multiple iterations of the furnace, and when the measured coefficient is greater than the target value, the speed is reduced in steps, and a thermal imager and a differential pressure instrument are introduced to monitor the smoke emission. A smoke emission rate statistics and tolerance threshold judgment mechanism is established to trigger speed backtracking adjustment, and finally the average secondary combustion coefficient of each time period is minimized to generate an optimal fan speed model. The present application maximizes the improvement of the calorific value of coal gas and the recovery of carbon monoxide under the premise of preventing smoke from the furnace mouth.

The invention relates to the technical field of weighing equipment, in particular to a control system for a mining intrinsic safety type belt weigher. The system comprises a conveying device used for conveying materials, an energy supply device used for supplying energy to the conveying device and a belt weigher used for measuring the materials, gravity information and speed information are obtained through a weighing unit and a testing unit in the belt weigher respectively, and then a conversion unit processes the gravity information and the speed information to obtain a pressure difference signal and a pulse signal; then the extraction unit obtains an instantaneous quantity and a cumulant based on the processing of the differential pressure signal and the pulse signal, the analysis unit judges whether the operation of the belt weigher in the current measurement period is qualified or not based on the calculated cumulant, if yes, the cumulant is output, and if not, the reason is determined and a corresponding correction instruction is generated; operating parameters of the corresponding devices or units are adjusted through the control unit based on the instructions; the self-adjustment of the system is realized by adjusting operation parameters, so that the material measurement precision of the belt weigher in the system is improved.

The invention discloses a lunar dust interference effect test platform suitable for a vacuum environment and a use method of the lunar dust interference effect test platform, and relates to the technical field of aerospace engineering ground simulation tests.The platform comprises a vacuum container system, a measuring system and a dustproof system; maintaining the normal-pressure and normal-temperature working state of the camera; the measurement system integrates a P IV camera, three high-speed cameras and a heat flow sensor, and realizes the multi-dimensional measurement of the moony dust excitation height / speed / impact range, the erosion pit three-dimensional reconstruction and the engine aerodynamic heat effect. The dustproof system adopts a high-transmittance acrylic dustproof cover and a vacuum gauge for differential pressure monitoring, so that lunar dust is prevented from polluting the heat sink, and the safety of the cover body is protected. The problems of pollution and single measurement of a vacuum system in the prior art are solved, multi-physical-quantity collaborative testing is achieved, key test data are provided for design of the lunar lander, and the method has engineering application value.

The utility model provides a differential pressure type liquid level transmitter, which relates to the technical field of liquid level transmitters and comprises a take-up box and a transmitter body. In use, through cooperative use of the take-up box, the top plate, the transmitter body and the take-up assembly, after the transmitter is fixed on equipment or an installation site, the transmitter body is pulled, the surface of a wire tiger rotating block rotates, a guide block is pulled, and when two sliding sleeves and two sliding blocks move backwards on the surfaces of two first fixing rods, the two sliding sleeves and the two sliding blocks move backwards. The two sliding blocks extrude the two springs, so that the two springs are deformed, shrunk, bent and folded to be drawn out in the take-up box, meanwhile, under the elastic reset action of the two springs, redundant wires on the outer side can be pulled into the take-up box, and the situation that when the wires are too long, the too long wires are prone to being wound and knotted, and attractiveness is affected is avoided; and the internal wire harness of the wire which is knotted for multiple times can be bent and damaged, so that the use effect of the differential pressure type liquid level transmitter is improved.

The invention relates to the technical field of fire monitoring, in particular to an intelligent fire monitoring and early warning method. A Gaussian distribution model is introduced to simulate the diffusion effect of a heat source, the adaptability of smoke flowing to airflow in a building is enhanced, limitation of a traditional smoke diffusion model is corrected and optimized according to local turbulence driven by differential pressure, especially the non-uniform airflow effect in areas such as narrow galleries and courtyards, and accurate monitoring and early warning of fire disasters are achieved. The expected speed and comfortable distance of the crowd are dynamically adjusted by combining light flow sensing with environment sensing (such as smoke concentration and temperature), and the problems of people flow and evacuation path optimization in a high-density scene can be effectively solved. Especially in a narrow space, interaction between crowds and obstacles can be fed back in real time, and secondary accidents caused by crowd density or high temperature and smoke influence are prevented.

The utility model discloses a heat exchanger capable of preventing pressure difference deformation, and particularly relates to the technical field of plate heat exchangers, which comprises a supporting frame, a plurality of guide rods are arranged on one side of the supporting frame through bolts, a movable clamping plate is arranged at one end of each guide rod, and a plurality of heat exchanger plates are arranged between the movable clamping plates and the supporting frame. A plurality of buffer partition plates are arranged among the heat exchanger plates. Due to the fact that the buffering partition plates are additionally arranged between the plates of the heat exchanger, fluctuation displacement of the plates can be reduced, the effect of a rigid baffle is achieved, deformation is not prone to occurring, and the service life of equipment is prolonged.

The invention relates to the technical field of sealing performance detection, and discloses a detection system and a detection method for detecting the two-way leakage rate of a spherical sealing valve of an aircraft bleed air system. The system comprises an air inlet device, a sealing device and a detection device, the gas inlet device provides clean test gas with controllable pressure; the sealing device is used for fixing the spherical sealing valve and simulating two sealing states of the spherical sealing valve in the high-pressure stage regulator to form two independent test gas paths; the detection device is connected with an outlet of the sealing device, is used for quantitatively or qualitatively detecting leaked gas and comprises a flow monitoring unit and a pressure difference monitoring unit; the sealing device can respectively test the sealing performance of the ceramic ball and the lift valve seat and the sealing performance of the ceramic ball and the valve mounting seat by replacing or adjusting the limiting structure; according to the invention, component-level bidirectional sealing performance detection is realized, the test precision and the maintenance efficiency are improved, defects can be identified before assembly, and the rework rate is reduced.

The present invention discloses a high-sensitivity micro-mechanical system (MEMS) differential pressure sensor and a preparation method thereof, wherein the differential pressure sensor comprises a silicon nitride (SiN) with an etched window. x ) thin films, silicon (Si) substrates, SiN x Suspended structure self-supporting film, PdSe2 polycrystalline ultra-thin film, metal electrode and surface passivation layer. Ultra-thin PdSe2 has significant piezoresistive effect and ultra-thin suspended SiN x The device has a high pressure differential stress sensing characteristic, and the high Young's modulus SiN x The device ensures the reliability of differential pressure sensing. The Wheatstone bridge formed by the optimized metal electrode structure suppresses temperature drift, ensuring the accuracy of differential pressure measurement. Advantages of this invention include compatibility with silicon-based semiconductor processes, high yield, strong repeatability, good stability, and high device sensitivity.