9 results about "Phase equilibrium" patented technology

The invention relates to the technical field of gas hydrate phase equilibrium tests, in particular to a gas hydrate phase equilibrium condition testing device and method under the normal pressure condition, and the testing device adopts a core framework integrating hydrate synthesis and phase equilibrium testing under the normal pressure into the same reaction kettle unit. And aiming at the functional difference of phase balance test under synthesis and normal pressure, independent high and low temperature control subsystems and pressure control modules are respectively arranged, so that the efficiency of a high-pressure synthesis stage is guaranteed, and the precision requirement of a low-pressure test stage is met. According to the testing method, a constant-volume gradual heating decomposition method is adopted, high-precision micro-pressure change monitoring is combined, and the phase equilibrium point of the hydrate under the low-pressure condition can be accurately captured. The problem that hydrate phase equilibrium experiment data in the area near the normal pressure is deficient is solved, and key data support can be provided for model verification and safety design.

The invention discloses a multi-component alloy solidification phase field simulation acceleration method based on a shallow neural network. The method comprises the following steps: constructing a parameter space according to characteristics of a target multi-component alloy system; solving a quasi-equilibrium thermodynamic nonlinear equation set based on the equal chemical potential condition and solute conservation to generate a quasi-equilibrium thermodynamic condition data set; constructing an artificial neural network model with a single hidden layer, and training the model by taking the parameter space and the quasi-equilibrium thermodynamic condition data set as input and output of the model respectively; solving an order parameter equation and a solute diffusion equation, inputting the phase components, solute component components and temperature of the current time step into a trained artificial neural network model, and outputting quasi-equilibrium thermodynamic conditions of the current time step; according to quasi-equilibrium thermodynamic conditions output by the model, chemical driving force of the current time step is calculated on the basis of the thermodynamic phase equilibrium principle and serves as initial driving force of the next time step, and loop iteration is conducted till simulation is finished.

The present application relates to gas hydrate phase equilibrium test technical field, especially to a kind of gas hydrate phase equilibrium condition testing device and method under normal pressure, testing device adopts the core architecture of hydrate synthesis and phase equilibrium test under normal pressure integration in same reaction kettle unit, and for the function difference of synthesis and phase equilibrium test under normal pressure, independently equipped with high-low temperature control subsystem and pressure control module, both guarantee the efficiency of high-pressure synthesis stage, meet the accuracy requirement of low-pressure test stage again.Testing method uses constant volume step-by-step warming decomposition method, combined with high-precision micro-pressure variation monitoring, can accurately capture hydrate phase equilibrium point under low-pressure condition.The present application solves the problem of lack of hydrate phase equilibrium experimental data in the vicinity of normal pressure, and can provide key data support for model verification and safety design.

This invention discloses a method for calculating the three-phase phase equilibrium of oil, gas, and water at the nanoscale, relating to the field of shale oil reservoir development technology. The method includes the following steps: receiving input parameters; constructing a total pressure model of the confined fluid at the nanoscale based on the input parameters; constructing a three-phase pressure equilibrium model among the oil, gas, and water phases at the nanoscale based on the total pressure model; constructing a phase stability test model, and determining whether phase separation occurs in the system under given temperature and pressure conditions based on the tangent plane distance function; when the phase stability test model determines that phase separation has occurred, calculating the phase fraction and composition of the oil-gas-water three phases by iteratively solving for the conditions satisfying the three-phase pressure equilibrium model and the equality of the fugacity of each phase component, and outputting the results. This invention can accurately and stably predict the fluid phase state in the nanopores of shale oil reservoirs, providing key technical support for its component simulation and efficient development.

The invention relates to the technical field of chemical process simulation, in particular to a gas-liquid flash calculation method and device, a medium and a product. The method comprises the following steps: acquiring initial parameters of a multi-component system, performing composition estimation on the multi-component system based on a preset thermodynamic equation, determining a liquid phase fugacity coefficient and a gas phase fugacity coefficient of each component, performing lower limit constraint on the fugacity coefficients, and determining a phase equilibrium constant of each component based on the constrained fugacity coefficients. The method comprises the following steps: constructing a gas phase fraction solving equation through a phase equilibrium constant and a feeding molar fraction, and determining a target expression corresponding to the gas phase fraction solving equation based on a relative size between a current gas phase fraction and a preset threshold value, so as to iteratively carry out mixed solving on the target expression to update the gas phase fraction until the gas phase fraction meets a preset convergence condition, the gas-liquid flash calculation result representing that the current phase composition of the multi-component system meets the gas-liquid two-phase equilibrium condition is obtained, so that the efficiency and the accuracy of gas-liquid flash calculation are improved.

The invention discloses a tailing filling body damage prediction method based on a phase change theory and acoustic emission parameters, and belongs to the field of structural health monitoring, and the method comprises the following steps: firstly, obtaining component and crystal structure data of a material, and constructing a self-consistent free energy function with a clear physical image; and then, inputting a free energy function into the phase change theoretical model, calculating and comparing free energy of different phases under different components and temperatures by solving equilibrium state conditions with the chemical potential phase as the core, thereby determining the thermodynamic stable phase and the coexistence relationship thereof, and finally outputting a predicted phase diagram. The method directly starts from the basic physical parameters of the material, the dependence on a large amount of empirical data and parameter fitting is remarkably reduced, the phase equilibrium relation between a new material system and a complex multi-element system can be efficiently and reliably predicted, and an efficient calculation tool is provided for material design and development.

The application is a liquid micro-leakage precision detection method based on liquid level pressure difference, and relates to the technical field of container leakage detection, comprising: removing outliers and smoothing filtering on the effective pressure difference time sequence to obtain an actual pressure difference sequence and a residual sequence, calculating an arithmetic mean and a standard deviation, and converting the standard deviation to obtain a pre-processed actual pressure difference sequence and a standardized theoretical pressure difference sequence.In the application, a thermodynamic quasi-steady state judgment mechanism can accurately identify the stable stage of the thermodynamic state of the container, avoid the influence of transient changes after pressurization on the detection result, and help shorten the detection period; through dynamic gas volume calculation and theoretical pressure difference decay sequence generation, the thermal expansion and cold contraction effect of the container and the liquid, the gas-liquid two-phase equilibrium, and the atmospheric pressure fluctuation and other factors are comprehensively considered, and the pressure difference change law under the condition of no leakage can be accurately simulated.

This invention discloses a method for predicting the phase equilibrium of gas hydrates based on the fusion of physical thermodynamic models and machine learning, comprising: S1: collecting mole fractions and temperature data of components in a gas mixture to generate an experimental dataset; S2: based on the experimental dataset, using a thermodynamic model to calculate the equilibrium pressure and determine the crystal structure type, generating a physical calculation result set; S3: based on the physical calculation result set, calculating the logarithmic difference between the experimental pressure and the predicted physical pressure, generating a logarithmic residual vector; S4: based on the physical calculation result set, constructing a feature matrix containing nonlinear and interactive features; S5: based on the logarithmic residual vector and the feature matrix, performing data partitioning and standardization to generate a training dataset; S6: based on the training dataset, training a gradient boosting model and an ensemble learning model and performing a weighted combination to generate a residual prediction model; S7: based on the residual prediction model and the predicted physical pressure, calculating the corrected equilibrium pressure.

The application belongs to the field of non-ferrous metallurgy equipment, and particularly discloses a design method of a graphite heating body of a bismuth refining vacuum furnace and the vacuum furnace. The design method comprises the following steps: S1, calculating a target temperature gradient required by each layer of evaporation tray in the vacuum furnace based on the thermodynamic phase equilibrium principle according to raw materials and target product purity; S2, deriving a functional relationship S=f(h) of the cross-sectional area S of the graphite heating body changing with the height h by combining the Joule's law, the resistance law and the radiation law; and S3, processing the variable cross-section graphite heating body according to the function. The vacuum furnace using the method has a variable cross-section structure. The application optimizes the shape of the heating body, accurately matches the heat supply with the component change requirement in the evaporation process of the material, ensures that the bismuth and silver content in the distillation meets the standard, significantly reduces the energy consumption, and improves the process adaptability.