145 results about "Ideal gas" patented technology

The invention discloses a compressed air energy storage optimization operation method based on multi-parameter cooperative control, and the method comprises the steps: multi-source data collection and preprocessing, thermodynamic state multi-dimensional parameter dynamic estimation, three-dimensional reconstruction and evolution prediction of a temperature field in a gas storage, and system loss analysis and efficiency evaluation based on an entropy generation theory. And multi-time scale energy flow dynamic tracking and state evaluation, and operation parameter optimization suggestion generation based on state evaluation. According to the method, accurate estimation of non-ideal gas parameters is realized through particle swarm-Bayesian hybrid inference, a temperature field in a gas storage is reconstructed, interlayer available energy transfer items are introduced to quantify temperature stratification influence, the operation efficiency and reliability of the system are improved, the service life of equipment is prolonged, and the operation cost is reduced.

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 provides a carbon dioxide phase change blasting numerical simulation method based on an FDEM. The carbon dioxide phase change blasting numerical simulation method comprises the following steps that a carbon dioxide adiabatic expansion p-V relation is determined according to a Span-Wagner fluid model; establishing a finite-discrete element (FDEM) numerical model, and setting a non-reflection boundary; determining mesoscopic parameters in the FDEM model according to the physical and mechanical parameters of the rock mass; and applying a carbon dioxide phase change blasting load, and solving a finite-discrete element (FDEM) model. According to the method, the Span-Wagner fluid model recommended by the American national standard is adopted to replace a traditional ideal gas model to calculate the adiabatic p-V relation of the carbon dioxide, the description of the carbon dioxide pressure is closer to the reality, the value of the FDEM mesoscopic parameter is associated with the physical and mechanical indexes of the rock mass, a theoretical basis is provided, the reasonability of the parameter value is ensured, and the method has the advantages of high reliability and high reliability. Therefore, a carbon dioxide blasting numerical simulation result is close to an actual application result, and the accuracy of the numerical simulation result is improved.

The invention belongs to the field of target detection, particularly relates to a bubble detection method based on multi-modal input and an improved target detection network, and aims to solve the problems that an existing bubble detection model is sensitive to environmental parameter changes, depends on a large amount of annotated data, is poor in migration adaptability, lacks multi-modal information fusion and physical law constraints, and is poor in migration efficiency. The precision is low and the cost is high. According to the method, gas-liquid two-phase flow images and temperature, pressure and flow velocity parameters are collected, a target detection network is constructed, and multi-scale visual features are extracted. After physical parameters are coded into high-dimensional features, a comprehensive feature map is generated through dynamic weighted fusion, and a detection head is input to output a bounding box and convert the bounding box into an actual size. An ideal gas equation and fluid mechanics are adopted to construct a physical constraint loss function correction size, environment self-adaption is achieved in combination with a dynamic weight adjustment and fine adjustment mechanism, and the detection precision and physical consistency are improved. According to the method, the bubble detection precision and the environmental adaptability are improved, and the labeling cost is reduced.

The invention relates to the technical field of safety monitoring, and discloses a linkage monitoring method and system for a gas leakage alarm and a gas meter, and the method comprises the steps: periodically regulating and controlling the temperature of a gas sensor, obtaining monitoring values at different temperatures, calculating a specific value, and recognizing gas leakage and non-leakage gas sources; when leakage is judged, activating a camera to shoot an image of a gas meter counter, synchronously acquiring temperature and pressure data, and uploading the temperature and pressure data to a data processing center; a gas consumption value is extracted based on an image recognition algorithm, environmental interference is corrected in combination with an ideal gas state equation and a dynamic compensation model, and high-precision gas consumption is generated; and by analyzing the time sequence relevance between the corrected consumption and the leakage signal, if an abnormal condition is met, the valve is automatically closed, and an alarm is given. According to the invention, high precision, low false alarm and quick response of gas leakage detection can be realized.

The invention relates to a flow battery gassing side reaction real-time monitoring method and a flow battery gassing side reaction real-time monitoring system, and the flow battery gassing side reaction real-time monitoring method comprises the following steps: collecting the concentration of each side reaction gas, and obtaining the gas phase volume, the current test moment, the gas phase pressure and the gas phase temperature in a liquid storage tank; calculating the increment of each side reaction gas generated by the flow battery in a preset time period according to the sealing condition of the liquid storage tank; calculating a side reaction gas generation rate in a preset time period according to each side reaction gas increment; and calculating the side reaction proportion of the flow battery in the preset time period according to the side reaction gas generation rate and the average current in the preset time period. According to the invention, the ideal gas state equation and different constant physical quantities during opening and closing of the liquid storage tank are utilized, and the working current is combined, so that the obtained gas side reaction proportion during each sampling is more accurate.

The invention belongs to the technical field of engine nozzles, and relates to a design method, device and equipment of an ultra-high-speed non-ideal gas nozzle and a medium. The method comprises the steps that design parameters are obtained, a non-sticky molded surface and a contraction section of the ultra-high-speed non-ideal gas spraying pipe are designed, and a flow field of the ultra-high-speed non-ideal gas spraying pipe is obtained; carrying out computational fluid mechanics simulation on the flow field by adopting a computational fluid mechanics method, and calculating the boundary layer thickness of the ultra-high-speed non-ideal gas nozzle; according to the thickness of the boundary layer, a non-sticky molded surface and a contraction section of the ultra-high-speed non-ideal gas spraying pipe are redesigned, the thickness of the boundary layer is corrected, and an updated flow field is obtained; performing computational fluid mechanics simulation on the updated flow field by adopting a computational fluid mechanics method to obtain an updated flow field simulation result; and when it is judged that the updated flow field simulation result meets the preset requirement, the current ultra-high-speed non-ideal gas spraying pipe is output. The ultra-high-speed non-ideal gas spray pipe can be accurately designed.

The invention discloses a safety early warning system, which relates to the technical field of early warning regulation and control, and comprises an acquisition and processing module, an analysis and prediction module and an early warning regulation and control module, the acquisition processing module measures the temperature and the pressure in the current period, and processes the temperature and the pressure in the historical period into a standard data tensor; the analysis and prediction module establishes a matching degree matrix through dynamic time warping, introduces physical regular constraint into principal component analysis based on an ideal gas equation, extracts and generates a coupling feature sequence, splices the coupling feature sequence with a standard data tensor, inputs the coupling feature sequence into a prediction model, outputs a prediction data tensor, and performs fitting to generate a trend function of temperature and pressure; and the early warning regulation and control module dynamically judges a dangerous moment and dynamically determines a regulation and control time length, performs model prediction control based on an equipment regulation and control model, defines a regulation and control objective function, solves an optimal regulation and control problem in a limited time length, obtains an optimal parameter adjustment quantity vector, and executes regulation and control. And accurate prediction and regulation and control considering the temperature and pressure coupling relationship and the adjustable and controllable time length are realized.

The invention discloses a continuous equipment temperature distribution optimization control method and system, and belongs to the technical field of temperature control, and the method specifically comprises the steps: monitoring equipment production process parameters in real time, and transmitting the parameters to a control center; the control center corrects the parameters by using a compensation algorithm constructed based on an ideal gas state equation, extracts furnace temperature data from the corrected parameters, calculates a control signal according to the deviation between the furnace temperature data and a preset furnace temperature target value by adopting PID (Proportion Integration Differentiation) operation, and adjusts the opening degree of a gas actuator to obtain a corrected gas flow value; calculating required combustion-supporting air flow according to the value and a preset air-fuel ratio, and adjusting a combustion-supporting air actuator to stabilize heat supply in the furnace; when the furnace temperature is stable, an online temperature measurement thermal imager is used for collecting the temperatures of five point positions of the pipe body, the average value is calculated and compared with the temperature required by the process, and then the left and right temperature adjustment areas are adjusted; the method can effectively improve the stability of equipment production and the product quality.

The invention provides a vacuum pressure system, a parameter identification method and a parameter identification modeling method, which are applied to the technical field of semiconductor manufacturing, a mathematical model for describing the change of the pressure in a chamber along with time is constructed by applying the law of conservation of mass and an ideal gas state equation, the change of the pressure in the chamber can be accurately predicted, and the accuracy of the parameter identification is improved. And key system parameters can be determined in real time through a parameter identification process, so that the precision and the response speed of pressure control are remarkably improved, meanwhile, the adaptability and the stability of the system are enhanced, the thin film deposition process can be optimized, the quality and the uniformity of products are improved, and the production efficiency is improved.

The invention discloses a method for collecting and verifying gas generated by thermal runaway of a battery in a closed pressure container, which comprises the following steps of: 1, starting a power supply of an experimental device, debugging each component and trying to act, putting the battery with a clamp into the closed pressure container 1, and closing a cabin door of the container; step 2, vacuumizing the transformed large-volume closed pressure container 1 until the transformed large-volume closed pressure container 1 reaches a vacuum environment, then filling nitrogen, monitoring and recording the nitrogen concentration through a nitrogen concentration sensor 1-2, and inputting data into a control system 6; a plurality of nitrogen concentration sensors are arranged at a plurality of gas sampling ports of a closed pressure container, a nitrogen concentration sensor is arranged in a premixing cabin, and an ideal gas state equation, a gas homogenization calculation method and an automatic adjustment algorithm are integrated in a control system. By utilizing the flow rate adjusting function of the sampling pipeline and actually measured concentration data, the automatic detection, adjustment and verification of the uniformity degree of the thermal runaway mixed gas sample are realized.

The invention discloses a natural gas-diesel oil injection switching control system of a dual-fuel diesel engine, which relates to the technical field of automatic control and comprises a data acquisition monitoring module, a fuel analysis module, a prediction control module, a control optimization module and a switching protection module. Engine operation parameter data are collected in real time through an engine sensor interface and preprocessed, and fuel dynamic proportion analysis is carried out according to different rotating speeds and load intervals of an engine by taking a preset proportion as an initial reference datum and applying an intelligent algorithm; the engine can obtain the most appropriate natural gas and diesel oil mixing proportion under various working conditions, according to an ideal gas state equation, based on pressure and temperature data, monitored in real time, in a gas supply pipeline, dynamic compensation is conducted on the gas volume flow, real-time gas supply energy is calculated, the gas supply amount can be accurately controlled in the mode, and the gas supply efficiency is improved. It is guaranteed that the engine obtains stable and accurate energy supply, and therefore stable operation of the engine is maintained.

According to the bimodal oxygen control continuous cooling closed-loop fluid system and the precise control method, precise control over the oxygen content in closed-loop fluid equipment is guaranteed; the continuous cooling closed-loop fluid system comprises a compressor section, a liquid nitrogen injection section, a heat exchange section, a stable section, a test cabin section, a diffusion unit, an oxygen injection section and a steering unit which are sequentially connected and form a circulation shaped like a Chinese character'hui ', an oxygen content detection assembly is assembled between the stable section and the test cabin section, and an oxygen injection assembly is assembled on the oxygen injection section. The oxygen injection assembly comprises a feed-forward control pipeline and a feedback control pipeline, receives a feed-forward control instruction of the PLC, and automatically injects along with liquid nitrogen according to liquid nitrogen injection data by combining an ideal gas equation with a correction equation or an oxygen molecule demand calculated by a simulation mode value; the feedback control pipeline receives a PID feedback control instruction, and the feedback control instruction calculates the demanded quantity of oxygen supplementation molecules through real-time oxygen content data obtained by the oxygen content measuring assembly and liquid nitrogen injection data.

The invention provides a method for simulating the influence of montmorillonite clay mineral water on organic matter pyrolysis hydrocarbon generation, and belongs to the technical field of organic matter pyrolysis. The method comprises the following steps: heating montmorillonite to obtain dehydrated montmorillonite, mixing organic matters and the dehydrated montmorillonite in an argon atmosphere and a dry environment, transferring a mixed sample into a gold tube, and loading the sample; putting the gold tube into an iron reaction kettle, filling the reaction kettle with water, and cooling after heating reaction; putting the cooled gold tube into a gas collecting device, and calculating the amount of substance of gas according to an ideal gas state equation; the collected gas is subjected to GC analysis to obtain the percentage of each gas, the yield of each gas is calculated by combining the amount of substance of the gas, and the influence of the montmorillonite clay endogenous water on hydrocarbon generation by thermal decomposition of organic matters is evaluated. Under the condition that only the unified boundary condition of clay mineral water is changed, a verifiable judgment system of'endogenous water type-product spectrum characteristic-reaction channel 'is established for the first time.

The application discloses an air dynamic test platform vacuum equipment leakage fault diagnosis method and system, aiming at solving the problems that the existing method is difficult to adapt to the complex time-varying characteristics of mixed gas, data is sparse, and lack of interpretability. The method first collects time series pressure data through a conventional pressure sensor, uses the ideal gas state equation as a physical mechanism model, deduces a leakage rate calculation equation, and extracts key characteristics of instantaneous leakage rate and cumulative leakage rate; then a BP neural network is constructed as a data-driven model, taking the leakage rate as input, and outputting normal and abnormal judgments after training with historical data. The application innovatively integrates physical mechanism and machine learning, without the need for special detection equipment, ensuring the interpretability of the diagnosis results, improving the diagnosis accuracy and reliability under small sample and variable working conditions, and realizing high-precision, low-cost air tightness online monitoring and early warning.

The invention discloses a method and device for estimating residual waste gas in a cylinder of a hydrogen combustion range extender, a vehicle and a medium, and relates to the technical field of vehicle engines, and the method comprises the steps: building a waste gas flow model at an exhaust valve based on engine structure parameters, a pressure signal and a temperature signal of an exhaust manifold, and exhaust efficiency; on the basis of the inlet waste gas flow of the exhaust manifold and the outlet waste gas flow of the exhaust manifold, according to the mass conservation relation and the ideal gas state equation, an exhaust pressure average value discrete dynamic model of the exhaust manifold is built; constructing a self-adaptive observer based on an exhaust pressure average discrete dynamic model, and estimating the exhaust efficiency; according to the online estimation result of the exhaust efficiency, the mass of exhaust gas exhausted in each cycle is obtained, and the amount of residual exhaust gas in the cylinder is calculated. By adopting the method, the mass of exhaust gas in each cycle and the amount of residual exhaust gas in the cylinder can be accurately estimated in real time in the actual vehicle running process, so that reliable reference is provided for combustion control and emission optimization.

The invention provides an escaping carbon source emission monitoring method and system and a medium, and belongs to the technical field of carbon emission monitoring. The method comprises the steps that a pressure sensor is installed on the side, close to an indoor unit, in a refrigerant pipe connecting the indoor unit and an outdoor unit of refrigeration equipment, and a temperature sensor is installed in the refrigerant pipe of the indoor unit; when the refrigeration equipment is in a stable operation working condition and the external environment condition is constant, temperature regulation and control are started, the temperature of a refrigerant in a refrigerant pipe of an indoor unit is regulated and controlled and stabilized at a preset temperature, real-time pressure data collected by a pressure sensor are obtained, smooth filtering processing is carried out, and an average pressure value is obtained; and a pressure and medium quantity relation model is established based on the ideal gas state equation, the refrigerant dissipation amount is calculated by combining the initial pressure value and the initial refrigerant mass in the refrigerant pipe obtained during initial filling and the calculated average pressure value, and then the refrigerant dissipation amount is pushed to an enterprise carbon management platform. According to the invention, the sensor layout and algorithm are optimized, refrigerant dissipation is accurately monitored, and carbon emission accounting is realized.

The invention belongs to the field of marine seismic exploration, and particularly relates to a non-ideal gas gun wavelet simulation method based on a unified bubble theory, which comprises the following steps: acquiring sea environment parameters; designing air gun working parameters and an air gun array; calculating the bubble radius, the bubble volume, the bubble pressure, the bubble heat loss rate, the gas release rate, the bubble volume change rate and the bubble temperature change rate at each moment according to the sea area environment parameters, the air gun working parameters and the air gun array; and calculating a pressure signal generated at any point in the seawater by bubble oscillation at each moment. According to the method, a non-ideal gas thermodynamic state equation is introduced on the basis of a traditional bubble dynamic model, and an evolution mechanism of the whole process of generation, expansion, contraction and the like of bubbles is considered in a unified manner on the basis of a unified bubble theory, so that sound wave wavelet signals generated by an air gun in an actual working environment are simulated more accurately; and the accuracy and adaptability of neutron wave modeling and inversion in seismic exploration are improved.

The utility model discloses an aero-engine ignition device air leakage quantitative detection device which comprises a working mechanism, adjusting mechanisms and a lifting mechanism, the adjusting mechanisms are arranged on the two sides of the working mechanism, and the lifting mechanism is arranged at the bottoms of the working mechanism and the adjusting mechanisms; the working mechanism comprises a first sealing tank, one side of the first sealing tank is fixedly connected with an ignition device, one side of the first sealing tank is fixedly connected with a first barometer, and one side of the ignition device is fixedly connected with a second sealing tank. In the utility model, the internal volumes of the first sealing tank and the second sealing tank are known, the air pressure of the first sealing tank and the second sealing tank can be measured according to the first barometer and the second barometer, the theoretical value of the second sealing tank at the moment can be calculated according to an ideal gas state equation, and then the theoretical value is compared with the actual value measured by the second barometer; therefore, the current air leakage can be accurately calculated, and the problem that the air leakage cannot be measured and calculated is avoided.

The invention provides an energy storage container pressure building and energy storage stage volume linear variable process modeling and simulation method. The method comprises the steps that a pressure-time mathematical model in a container in the energy storage process of a hydraulic compressed air system is established; initial pressure building and energy storage are divided into four sub-steps, liquid is alternately pumped into two acting containers, pressurized gas is pushed to enter an energy storage container, and multiple times of inflation are completed in a circulating mode; based on 12 thermodynamic assumptions (such as temperature uniformity, ideal gas state, quasi-steady state process and the like), deriving functions of pressure and gas volume changing along with time; and a pressure change curve is obtained through simulation calculation. According to the method, the dynamic characteristics of the energy storage process can be accurately described, the change relation between physical quantities is reflected, a theoretical basis is provided for system working condition analysis, parameter matching and optimization design, meanwhile, an ideal mathematical model is established by simplifying coupling factors, and a target is provided for calculation of the maximum energy storage capacity of the system.

The invention discloses a method for improving engine gas pressure stability, which comprises the following steps: calculating energy change and friction loss in a combustion process according to a first law of thermodynamics and an ideal gas state equation, and establishing a combustion thermodynamic model and a differential equation of gas pressure changing along with a crank angle; basic parameters of an engine are set, an improved Euler formula is used for solving the differential equation, and a fuel gas pressure curve generated when a crank rotates within one period is obtained; and the change range of the target parameters is set, and the influence of different parameter values on the gas pressure curve is analyzed, so that key parameters are optimized, the engine performance is improved, and the gas pressure stability is improved.

The invention is suitable for the field of petrochemical engineering, and provides a gas station breathing process VOCs emission amount correction method based on the type of an oil gas recovery vacuum pump. Calculating the pressure increment caused by excessive oil gas recovery (the gas-liquid ratio is 1.1) and reverse air leakage of a vacuum pump in the oil tank in the secondary oil gas recovery process, and deducing a correction formula of VOCs emission factors; secondly, a discharge amount correction model is established by combining the use proportion and the leakage proportion of a gas station fixed-frequency pump, the installation proportion of a three-time oil gas recovery device and the annual gasoline sales volume; the accuracy of discharge amount calculation is verified by actually measuring the single discharge amount of VOCs at the P / V valve of the gas station and monitoring the opening and closing frequency of the P / V valve. According to the method, the problem that the influence of an existing method on reverse leakage of the fixed-frequency pump is ignored is solved, the precision of checking the VOCs emission amount of the gas station is remarkably improved, and a reliable basis is provided for precise pollution control and gas station VOCs emission supervision.

The application provides a dynamic measurement method and system based on parallel differential pressure analysis, and relates to the technical field of gas-liquid mass transfer measurement. The method adopts a measurement unit and a control unit in parallel, a first closed container of the measurement unit containing liquid and gas, and the initial volume of the gas phase in a second closed container of the control unit being the same as the volume of the gas in the first closed container. After the pressure of the two containers is synchronously and suddenly increased to the initial pressure P0 by synchronous pressure excitation, the system is closed, and the pressure decay curves P1(t) and P2(t) in the two containers are synchronously collected. After differential processing, the influence of system leakage is eliminated, and the net pressure decay curve ΔP(t) is obtained. Based on the ideal gas state equation, the change amount of the dissolved gas mass with time is inversed, and the dissolution kinetics data are obtained. The application can dynamically and accurately measure the gas dissolution process, effectively eliminates the leakage interference, and provides key dissolution kinetics data for gas-liquid mass transfer engineering.

A vegetation concrete porosity measuring device comprises a sample chamber, a reference chamber, an inert gas filling tank, a recovery tank, a vacuumizing pump, a barometer, a communicating pipe, a valve and a gas pipeline. Wherein the sample chamber and the reference chamber are sealed and independent glass containers, are connected through a communicating pipe and are controlled to be opened and closed by a valve I; a barometer I is installed on the reference chamber, and a barometer II is installed on the sample chamber. One side of the reference chamber is respectively connected with a first vacuumizing pipeline and an inflating pipeline; and one side of the sample chamber is respectively connected with a second vacuumizing pipeline and a gas recovery pipeline. According to the determination method, an ideal gas equation is taken as a principle, and the porosity of the vegetation concrete is obtained by determining the pressure change of the two chambers. The vegetation concrete porosity measuring device provided by the invention can improve the accuracy and efficiency of vegetation concrete porosity measurement.

The invention provides an energy storage container pressure building and energy storage stage constant power isothermal process modeling and simulation method, which comprises the following steps of: firstly, building a dynamic mathematical model of an energy storage process of a hydraulic compressed air system, and circularly executing an initial pressure building and energy storage stage by dividing the initial pressure building and energy storage stage into four sub-steps; the compressed gas enters the energy storage container, and meanwhile liquid backflow is completed. Modeling is based on six assumed conditions including an isothermal process, an ideal gas state equation and the like, and a function relation between pressure and gas volume changing along with time is deduced. A dynamic curve of the pressure changing along with time can be obtained through simulation calculation. The method can accurately describe the dynamic characteristics of each physical quantity in the energy storage process, provides a theoretical basis for system working condition analysis, parameter matching and optimization design, simplifies complex coupling factors, and establishes a maximum energy storage capacity mathematical model under ideal conditions.

The present invention discloses a method for simulating a fast-filling vertical pipeline considering the energy dissipation of trapped air, including: establishing a continuity equation and a pressure balance equation of a moving air-water interface; building a heat transfer model based on the water hammer theory and combining the heat transfer principle of a closed airbag and the equation of an ideal gas; using a first-order local MOC interpolation interface tracking method to solve the filling water column control equation and the air heat transfer equation considering unsteady friction, and calculating and obtaining the air pressure, velocity and position of the moving air-water interface; using the Runge-Kutta fourth-order numerical integration method to solve; simulating according to the solution result to obtain the simulation result. The present invention studies a heat transfer model considering the energy dissipation of trapped air, which can explain the white fog and hot pipe wall phenomena in related experiments and solve the accuracy problem of traditional models. It is of great significance for the heat transfer of trapped air pockets in actual fast-filling vertical pipelines and the energy consumption simulation of violent air-water interactions.

The invention discloses a method for measuring the gas content in a die casting, and belongs to the technical field of material detection. The method comprises the following steps: loading a sample into the closed desorption cavity; vacuumizing and pre-degassing the cavity by using an oil-free high-vacuum acquisition module formed by connecting a molecular pump and a dry-type screw pump in series; stepwise heating is carried out on the sample through program temperature control; the released gas is guided into a differential pressure sensing metering unit through a low-thermal-conductivity aluminum oxide ceramic isolation tube; the unit comprises a reference cavity and a measuring cavity which are arranged in the same constant temperature device, and the gas inflow rate is dynamically represented by measuring the pressure difference between the two cavities; and based on the ideal gas state equation and a calculation model containing cavity thermal expansion compensation, calculating the amount of the gas substance in unit time in real time. The problems of poor precision and repeatability caused by oil pollution, thermal interference and discontinuous metering are solved, and continuous, dynamic and high-repeatability automatic measurement of the gas content in the die casting is realized.

The invention relates to the technical field of coal mine safety, and provides a protected layer goaf residual coal gas desorption method and system. The method comprises the following steps: calculating an ideal gas desorption rate of residual coal at a working face open-off cut distance # imgabs 1 # at a desorption time # imgabs 2 # according to a goaf theoretical temperature at a working face open-off cut distance # imgabs 0 # in a protected layer goaf residual coal gas desorption process; meanwhile, according to a goaf residual coal lumpiness actual measurement value, a residual coal thickness actual measurement value and an actual measurement gas desorption rate at different distances from the working face open-off cut, a desorption correction coefficient # imgabs5 # of residual coal at the distance # imgabs3 # from the working face open-off cut at desorption time # imgabs4 # is calculated; and the ideal gas desorption rate and the desorption correction coefficient are input into the constructed gas desorption correction model, and the corrected gas desorption rate of the residual coal at the desorption time # imgabs7 # at the working face open-off cut distance # imgabs6 # is determined, so that the accuracy and the reliability of the gas desorption analysis of the residual coal in the goaf are effectively improved.

The invention provides a modeling and simulation method for a pressure linear isothermal process in a pressure building and energy storage stage of an energy storage container. The modeling and simulation method comprises the following steps: establishing a pressure-time mathematical model in the container in an energy storage process of a hydraulic compressed air system; an initial pressure building and energy storage stage is divided into four sub-steps, and multi-cycle compression and transfer of gas are achieved by alternately using two acting containers; based on six idealized assumptions (including an isothermal process, an ideal gas state equation and the like), a thermodynamic law is combined to derive functions of pressure and gas volume changing along with time; and finally, a pressure-time change curve is obtained through simulation calculation. According to the method, the dynamic characteristics of the energy storage process can be accurately described, the dynamic relation between physical quantities can be revealed, a theoretical basis is provided for system working condition analysis, parameter matching and optimization design, meanwhile, a maximum energy storage capacity mathematical model under ideal conditions is established by simplifying coupling factors, and the method has important engineering application value.

The invention relates to the technical field of hub casting molds, and discloses a split type top mold structure which comprises a top mold, a negative pressure cavity, a heating ejection assembly and an air exhaust self-compensation assembly. Through an automatic compensation mechanism of mechanical linkage, accurate filling can be achieved according to actual gaps after bubbles overflow, casting closed-loop control is achieved, it is effectively guaranteed that the density of castings is uniform, and the dimensional precision and the internal quality stability of products are guaranteed; distilled water is heated by means of waste heat of molten aluminum to generate steam to push a component to discharge redundant molten aluminum, extra energy is not needed, negative pressure self-circulation is achieved, external air exhaust equipment is not needed, the equipment purchase, operation and maintenance cost is remarkably reduced, and the green manufacturing concept is met. Through cooperative operation of the cooling pipe and the negative pressure cavity based on an ideal gas state equation, stable negative pressure circulation is achieved, it is guaranteed that the negative pressure cavity is in an ideal negative pressure state before casting every time, and the stability of the casting technology is improved.