116 results about "Energy balance equation" patented technology

The invention discloses a method and a system for partitioning total output of a single shaft gas-steam combined cycle generating set. The method comprises the following steps: (a) establishing a mathematical model of a gas compressor, a combustion chamber and a gas turbine; (b) acquiring a real-time production parameter of the generating set; (c) calculating the power of the gas turbine and the consumed power of the gas compressor according to the results of the steps (a) and (b); (d) deducting the consumed power of the gas compressor from the generated power of the gas turbine to obtain the output of the gas turbine; (e) listing a material balance equation and an energy balance equation for a waste heat boiler; and (f) establishing a mathematical model of a steam turbine, listing a heat balance equation for the waste heat boiler, and calculating the output of the steam turbine through the mathematical model of the steam turbine. The method and the system can master the contributions of the gas turbine and the steam turbine to the total output of the set and the performance of each key part in real time so as to perform effective adjustment and control according to the actual conditions of the set.

The invention relates to a leaching rate prediction and optimization operation method in the wet metallurgical leaching process. The method comprises the following steps: predicting a leaching rate by an established mixing model and giving optimization operation instructions, wherein an integrative dynamic mechanism model of the leaching process is established, and a material balance equation and an energy balance equation are gradually established in the leaching process on the basis of the ore-leaching dynamic principle of the integrative dynamic mechanism model. The device comprises a leaching rate prediction and optimization operation system in the leaching process, a host computer, a PLC and a field sensing transmitting part which comprises a pH value detecting instrument, a temperature detecting instrument, a flow detecting instrument, and the like. With the technical scheme, the leaching process can be greatly improved, the production can be constantly kept in an optimal state, the consumption of raw materials and energy sources is reduced, the operation period of equipment is prolonged and the relation change between supply and demand on markets can be reflected in time.

A numerical procedure is disclosed to improve the prediction of heat fronts when simulating hot fluid injection in viscous hydrocarbon reservoirs. The mathematical model is composed of the conventional governing equations that describe multiphase fluid flow and energy balance. The reservoir geometry can be partitioned into a regular Cartesian grid or an irregular corner-point geometry grid. The numerical procedure uses the finite different (FD) method to solve the flow equations and the discontinuous Galerkin (DG) method to solve the energy balance equation. The proposed FD-DG method is an alternative to the traditional solution procedure that uses the FD method to solve both the flow and the energy equations. The traditional method has the deficiency that it may require excessive number of grid cells to achieve acceptable resolution of the heat fronts. The proposed FD-DG method significantly reduces numerical dispersion near discontinuities in the solution of the energy equation and therefore provides a better capture of the heat fronts. To obtain a desired accuracy in the energy equation solution, the FD-DG method can be orders of magnitude faster than the traditional method. The superiority of the FD-DG method is that it converges on coarser grids while the traditional method requires much finer grids.

The invention discloses a self-adaptive double-layer sliding mode-based teleoperation system fast force estimation method. One or two three-degree-of-freedom robots are adopted to form a teleoperation robot system. In the load-free condition, the quality and length information of the connecting rod of a robot is measured. According to an energy balance equation, a second-order Lagrange system model is established in the task space of the teleoperation system. By utilizing the position encoder of the robot itself, the position signal of the robot is measured. According to the position information of the robot, a self-adaptive double-layer super-spiral sliding mode full-dimensional observer is designed. Meanwhile, the evaluation method of the estimated force is obtained through the observed information. According to the sizes of different external forces in different working environments and the changing conditions of the external forces, a large enough observer parameter is selected so as to ensure the stability of the observer system. The method is low in cost and insensitive to interference. The robustness of a closed-loop system is enhanced.

Embodiments for an engine exhaust are provided. In one example, a method comprises adjusting a fuel injection amount based on a fractional oxidation state of a catalyst, the fractional oxidation state based on reaction rates of a plurality of exhaust gas species throughout a catalyst longitudinal axis and a set of axially-averaged mass balance and energy balance equations for a fluid phase and a washcoat of the catalyst. In this way, a simplified catalyst model may be used to control air-fuel ratio.

The invention discloses a remote sensing retrieval method for moisture of farmland soil. The method is based on an energy-balance equation and TVDI, and provides a quantitative dry and wet edges determination method and an improved TVQI model-temperature vegetation quantitative index (TVQI). The method is characterized in that A) forming a vegetation index-ground temperature characteristic space based on a remote sensing image observation value, according to the surface energy-balance equation, obtaining a quantitative dry edge, wherein the quantitative dry edge is determined by two points of Tds and Tdv; B) obtaining the quantitative wet edge, wherein the quantitative wet edge is determined by two points of Tws and Twv; and C) according to the TVQ1 model, calculating a soil moisture estimate value. The method overcomes restriction of vegetation cover types in calculation of VI-Ts characteristic space, and remote sensing retrieval precision of soil moisture can be increased.

Embodiments for an engine exhaust are provided. In one example, a method comprises adjusting a fuel injection amount based on a fractional oxidation state of a catalyst, the fractional oxidation state based on reaction rates of a plurality of exhaust gas species throughout a catalyst longitudinal axis and a set of axially-averaged mass balance and energy balance equations for a fluid phase and a washcoat of the catalyst. In this way, a simplified catalyst model may be used to control air-fuel ratio.

The invention relates to a soft sensing method for true temperature of pyrolysis mixed products at the outlet of an ethylene cracking furnace, comprising the following steps: firstly obtaining the furnace tube parameters of the cracking furnace; then obtaining the information of cracking raw material; then calculating the composition of pyrolysis products at the outlet of the cracking furnace; according to a cracking process model, including mass balance equation, momentum balance equation and energy balance equation, calculating the composition profiles of the pyrolysis products at the outlet of a radiant section; then calculating coking thickness in a cracking furnace tube; calculating coking thickness in a adiabatic segment furnace tube according to the contents of small molecule unsaturated hydrocarbon and aromatic hydrocarbon in the pyrolysis products and running time; and finally calculating the difference value of the temperature of a measurement and control point and the true temperature of pyrolysis mixed products so as to calculate the true temperature of pyrolysis mixed products at the outlet of the ethylene cracking furnace. Through the method, the true temperature of gas mixture of pyrolysis products at a particular moment of time can be dynamically calculated, and accurate model of the ethylene cracking furnace can be established, so that the method provides the basis for the simulation, optimization and control of cracking process.

The invention discloses an energy theory-based prediction method for stress of a TMB (tunnel boring machine) disk hob. The prediction method comprises the following steps: (1) determining the normal pushing vertical force FV, the tangential rolling force FR and the lateral force FS of the hob in a rock breaking process; (2) establishing a hob stress model in the rock breaking process; (3) establishing a rock strain model during the rock breaking process of the hob; (4) establishing an energy-balance equation for the hob and rock; (5) according to the established rock strain model, by setting the principal stress direction of the rock and the principal stress direction of the hob under a cylindrical coordinate to be corresponding, obtaining surface forces on a wedge-shaped surface when the hob breaks the rock, and predicting the stress of the TMB disk hob. Aiming at analysis and research status of all influence factors in the mechanical property of the existing TMB disk hob, the invention discloses the microcosmic energy theory-based novel prediction method for the stress of the hob; through the influence of the added rotation speed of the hob on the stress characteristics of the hob to in previous studies, a basis is provided for the design theory of a cutter with TBM boreability.

The invention discloses a complex structure radiant heat exchange calculation method, and provides an improved Monte Carlo zone ray tracing method combining a Monte Carlo method, a zone method and a ray tracing method. The improved Monte Carlo zone ray tracing method solves the problem of possible self-zone radiation of a gas zone and is suitable for complex structure radiant heat exchange angle coefficient calculation. Besides, probability simulation statistics and temperature field iterative solution are separated, so that probability simulation of energy beams is omitted and only energy-balance equations need to be solved again when temperature fields change, and calculation amount is decreased.

The invention relates to modeling and optimization methods for the wax-oil hydrogen cracking process. The modeling method includes the steps that according to an industrial hydrogen cracking device, design parameters and operating data which are required by modeling are determined, and a hydrogen cracking lumped partition method is determined, wherein the design parameters comprise lengths and diameters of all beds, and the operating data comprises the feeding flow, inlet-and-outlet temperatures of all the beds, the relative density and distillation range data of feeding and a product and theproduct yield; a hydrogen cracking reaction network, a reaction kinetic equation, a material balance equation and an energy balance equation are determined; a hydrogen cracking mechanism model is solved; based on actual industrial operating data, the hydrogen cracking lumped kinetic parameters are corrected. The modeling and optimization methods for the wax-oil hydrogen cracking process are wide in adaptation and can be used for simulating and optimizing hydrogen cracking industrial reactors with different reaction-bed number times and different product yield requirements.

The invention relates to a method for calculating a nuclear island variable working condition heat storage increment of a pressurized water reactor nuclear power station. The method is characterized by comprising the following steps: (1) establishing an overall energy balance equation of a pressurized water reactor nuclear power unit primary coolant loop, a steam generator secondary side loop anda nuclear reactor by utilizing an energy conservation principle, and analyzing the energy balance equation to obtain a key variable influencing the nuclear island variable working condition heat storage increment of the pressurized water reactor nuclear power unit; (2) mathematical modeling is carried out on the obtained key variables, and the influence quantity of the key variables on the heat storage capacity under the variable working conditions is calculated through the obtained mathematical model; and (3) summing the calculated values of all the key variable mathematical models to obtainthe increment of the heat storage capacity of the nuclear power unit under the variable working condition of the nuclear island, thereby completing the calculation. By means of the calculation method,the problem that the nuclear power unit does not have a real machine test is effectively solved, and the calculation method capable of obtaining the nuclear island variable working condition heat storage increment of the nuclear power unit is provided.

The invention discloses a method for predicating the temperature of a photovoltaic cell through photo-thermal property coupling. The method includes the following steps that in combination with actual time and irradiance information provided by TMY data obtained through standard measurement, vertical equivalence is performed on incident light of the photovoltaic cell module, and based on an atmospheric dispersion longitudinal transmission model method, a vertical equivalence incident spectrum of a disperse wavelength is obtained; in combination with a crystal silicon layer texture structure and photo-thermal coupling properties of the anti-reflection process of an ARC layer, the wavelength dispersion absorption coefficient of each layer of the layered structure of the photovoltaic cell is calculated to obtained the flux of radiation absorbed by each layer of the structure; a layered structure energy balance equation of the photovoltaic cell is established, and a photovoltaic cell layered structure working temperature sequence corresponding to a time sequence is obtained through iterative calculation. On the basis of the existing function of predicating the output power of the photovoltaic cell, the function of predicating the working temperature of the photovoltaic cell module is further achieved, so that the precision of predicating the output power of the photovoltaic cell module is easily improved, and accordingly the output power of the photovoltaic cell module is accurately predicated.

The invention relates to a high-frequency response double-wire thermocouple, in particular to the double-wire thermocouple capable of accurately measuring fluctuating temperature. Two temperature voltage signals can be output simultaneously by two parallel butt-welded thermocouple wire structures made of different materials. Time constants of temperature measurement points of the two thermocouple wires can be accurately obtained by the maximum correlation analysis on the two signals or the minimization analysis on a difference value between the two signals. Then, an energy balance equation of the temperature measurement points is directly solved by the time constants, thus obtaining the real dynamic temperature of a measured media.

The invention discloses a method for measuring and calculating dynamic heat capacity of adiabatic reaction calorimetry samples. The method is provided with an adiabatic reaction calorimetry device with two-channel asymmetric sample pool structures, data of adiabatic condition reaction process and path offset reaction process can be measured by the adiabatic reaction calorimetry device and are processed by the aid of an energy-balance equation, and a specific heat capacity-temperature variation function of the samples close to real rules is acquired by the aid of constant approximation of an interpolation function and a dynamic estimation method of reactant concentration. According to the method, approximate heat capacity-temperature variation rules of the samples of the adiabatic reaction process can be acquired, key index-reaction heat calculated according to the heat capacity-temperature variation rules is closer to real conditions, and more accurate reference is provided for heat hazard evaluation of reactants.

The invention discloses a fast prediction method of expansion forms of multi-stage fracturing fractures of a horizontal well. The method comprises the following steps of building a global energy balance multi-fracture synchronous expansion model; solving the model; and obtaining the width, radius, inlet pressure and inlet flow rate of each fracture at each moment so as to obtain the expansion forms of the multi-stage fracturing fractures of the horizontal well. Through a global energy balance equation, the stress shallow influence is coupled with the fracture increase, so that the fluid distribution among various fractures is calculated; the stress mutual interaction is obtained by inducing a stress field model so as to build a complete multi-fracture synchronous expansion model; the optimization selection on construction parameters in the field construction process is facilitated; the hydraulic fracturing production increase effect can be effectively improved; and important significance is realized on the development of shale reservoirs and other unconventional reservoirs.

The invention discloses a method and a device for reconstructing a space temperature field based on target surface temperature distribution. A space unit radiation and convection energy balance equation set is built according to a local energy flow balance principle, a space thermal radiation energy absorption distribution random number is determined through a Monte-Carlo simulation method, and key parameters of space unit radiation absorption; space velocity field distribution is simulated through a computational fluid dynamics method, and space unit convection distribution parameters are provided; the target surface temperature is measured through an infrared temperature measurement device, and boundary conditions for equation solving are provided; and the radiation and convection energy balance equation set is solved so as to build a space temperature field. The method and the device provided by the invention can solve a technical problem of real-time reconstruction of the space temperature field, and engineering applications of the space temperature field are realized.

The invention relates to a multi-parameter energy-saving control method for a watering pipe network of an oil field, which mainly solves the problem that the existing crude oil watering transportation method is difficult to meet the on-site production requirement. The method is characterized in that a PLC control system acquires data sent from an instrument arranged on the on-site pipe network; the data is substituted to a physical equation to calculate a specific heat capacity C of the oil water mixture before the watering point and a specific heat capacity C of the hot water in a water inlet pipeline; the obtained known parameters into an energy balance equation set to calculate a flow rate q2 of the hot water in a required watering pipeline; and the PLC control system outputs a control signal according to the obtained flow rate q2 of the hot water to control an electric control valve to be adjusted to the corresponding opening.

The invention relates to a dynamic Gibbs reactor modeling method. According to the dynamic Gibbs reactor modeling method, firstly, a total enthalpy value of materials in a reactor is calculated according to a material equation and an energy conservation equation before a reaction and after the reaction; secondly, a post-reaction temperature T is assumed, material composition inside the reactor at the temperature T is calculated through the Lagrange Newton method according to the principle that Gibbs free energy tends to be minimum at the time of reaction equilibrium, and then the post-reaction total enthalpy value of the materials in the Gibbs reactor is calculated; thirdly, whether the assumed temperature T is reasonable is judged according to the energy conservation principle, a calculated result is output if the assumed temperature T is reasonable, and the cycle is executed again otherwise. According to the dynamic Gibbs reactor modeling method, an energy-balance equation is introduced innovatively to obtain the actual temperature of the reactor in an iteration mode; meanwhile, the material composition inside the reactor at the temperature is obtained according to the principle that the Gibbs free energy is minimum; the dynamic Gibbs reactor modeling method is more approximate to actual production.

The invention discloses a method for measuring hemispherical total emissivity and heat conductivity of a large temperature difference sample. The method comprises the following steps of: heating a belt-shaped conductor sample by electrifying under a vacuum environment, and arranging a plurality of thermocouple measuring points along the axial direction of the sample; forming a sample analysis region, and measuring to get the current value and the voltage value of the analysis region; dividing the sample into a plurality of infinitesimal control bodies along the axial direction, building a steady-state energy balance equation of the infinitesimal control bodies, and respectively expressing the hemispherical total emissivity and the heat conductivity as mathematical functions about temperature; performing multiple groups of steady-state measurement experiments under different steady-state temperature conditions to form a plurality of steady-state energy balance equations; calculating the temperature distribution of each infinitesimal control body under different steady states, and the total emissivity and the heat conductivity of each infinitesimal control body under different steady-state temperature conditions. According to the method disclosed by the invention, the problem that the hemispherical total emissivity of the large temperature difference conductor material sample of which the heat conductivity is unknown cannot be measured in the prior art.

The invention relates to a heat flow meter and a measuring method thereof. An incoming flow thermometer (2), an electric heater (4) and an inflow thermometer (5) are sequentially arranged on an inflow tube which enters heat-exchange equipment; a fluid is heated by the electric heater to differentiate the temperatures respectively measured by the incoming flow thermometer (2) and the inflow thermometer (5); and an integrator (8) is used for collecting the temperatures (T1, T2 and T3) of the fluid and electric power (W) to obtain heat energy released by the fluid in the heat-exchange equipment: (shown in the above formula), wherein C1-2 is average specific heat when the fluid is between T1 and T2, and C2-3 is average specific heat when the fluid is between T2 and T3. In the method, flow meters are replaced by thermometers, and the integrator is used for collecting the parameters of the incoming flow thermometer, the inflow thermometer and an outflow thermometer, so that the heat energy released by the fluid in the heat-exchange equipment can be obtained according to the energy-balance equations of the electric heater and the heat-exchange equipment. Furthermore the heat flow meter has the advantages of high measurement accuracy, simple structure and low cost.

Embodiments for an engine exhaust are provided. In one example, a method comprises adjusting a fuel injection amount based on a fractional oxidation state of a catalyst, the fractional oxidation state based on reaction rates of a plurality of exhaust gas species throughout a catalyst longitudinal axis and a set of axially-averaged mass balance and energy balance equations for a fluid phase and a washcoat of the catalyst, and further based on feedback from a downstream air-fuel ratio sensor. In this way, a simplified catalyst model may be used to control air-fuel ratio.

The invention relates to a catalytic cracking reaction system process simulation optimization model and a solution method thereof. A novel model is a model based on Gupta and the like; in order to contribute to solving the model in process simulation software such as AspenPlusTM, a new form is provided for part of expressions in a material balance equation, an energy balance equation and a fluidized state computation model; and components or stream physical property calculation subprograms provided by the process simulation software are called in the model solution process, so that the simulation optimization work of the model is finished by the process simulation software, the model is convenient to apply to engineering and the calculation result is accurate.

The invention discloses a method for thermoelectric coupling analysis of a double-glass photovoltaic module. Firstly, a simplified engineering mathematic model of the photovoltaic module is obtained according to physical models such as a single diode of a photovoltaic battery, and a simulation model of the photovoltaic module is established. Secondly, a heat exchange manner of the double-glass photovoltaic module is analyzed according to structure characteristics, physical characteristics and optical characteristics of the double-glass photovoltaic module; according to an energy balance equation, a relation equation of temperature, power, convection and thermal radiation of the module is established; and a temperature physical equation of the module is obtained. Finally, a thermoelectric coupling simulation model is established in combination with the engineering mathematic model and the temperature physical equation of the module, so that the thermoelectric coupling analysis of performance of the double-glass photovoltaic module can be achieved. The method disclosed by the invention makes up deficiency of existing models in consideration of temperature influences generated during performance research of the double-glass module, effectively makes up vacancy in the field, facilitates the performance research of the double-glass photovoltaic assembly and also facilitates further marketization of the double-glass photovoltaic module.

The invention relates to a hollow photovoltaic glass curtain wall heat performance calculation method, which comprises the following steps of S1, building an unsteady state heat transfer model of a hollow photovoltaic glass curtain wall; S2, obtaining environment data, performing cubic spline interpolation on the environment data, substituting the value into the model obtained in the step S1, and solving the photovoltaic assembly temperature, the substrate glass temperature and the photovoltaic assembly output power, wherein the environment temperature data includes solar radiation degree, environment temperature and air speed, and the unknown quantities in the model are photovoltaic assembly temperature, the substrate glass temperature and the photovoltaic assembly output power. Compared with the prior art, the method has the advantages that a heat transfer theory model of a hollow photovoltaic glass curtain wall system is built through a non-steady state energy balance equation; the influence of external environment on the system heat performance, and the influence of the substrate glass and indoor environment on the photovoltaic system heat performance are considered; the heat performance of the photovoltaic assembly is more accurately obtained, so that the photovoltaic assembly is favorably improved; the cold and heat load of a building is reduced.

The present invention discloses a dual-active bridge DC converter direct power control method based on energy closed loop, and is suitable for the field of large-power bidirectional direct current conversion. Aiming at the dynamic response problem of a bidirectional full-bridge direct current converter, on the basis of single phase-shifting control, according to an output energy balance equation,an output voltage Uout is sampled and then squared to construct an output capacitance energy closed loop, the size of a phase-shifting angle is obtained through the direct power based on the dual-active bridge direct current converter power transmission model to generate switching control signals so as to achieve rapid regulation of the output voltage of the dual-active bridge DC converter. The method provided by the invention can effectively improve the dynamic response speed of the output voltage when a load is suddenly changed, only needs to sample the output voltage, and is low in cost, not sensitive to model parameters and easy for design and engineering implementation.

The invention relates to a dynamic modeling method for syngas one-step dimethyl ether preparation. The method is a novel method for dynamical modeling for the syngas one-step dimethyl ether preparation and firstly shows that including heat loss into the energy conservation equation for performing iterative computation to judge whether the temperature in a reactor is reasonable so as to calculate the ingredients in the reaction according to atomic material conservation, reaction kinetics equation and energy conservation equation; when calculating, the temperature and the content of each ingredient in the syngas one-step dimethyl ether preparation reactor are assumed; the contents of the ingredients in the reactor are calculated through the material conservation equation and reaction kinetics equation, and then whether the assumed temperature is reasonable is determined through the energy conservation equation. According to the reactor-based dynamic modeling method for syngas one-step dimethyl ether preparation, a novel path is provided for the calculation of dynamic modeling for the dynamic modeling method for syngas one-step dimethyl ether preparation.

The invention discloses a coal-fired power station boiler reheater working medium flow online correction method. The method comprises the following steps: acquiring related boiler running data in realtime from an engineer station in a boiler distributed control system (DCS) after selecting fixed sampling time; establishing a working medium physical property parameter library for online computation of water and vapor enthalpy values; setting a design parameter of a boiler related superheater system according to boiler design drawing; performing dead pixel processing and data smoothing processing on the collected running parameter of the boiler; establishing a boiler reheating system working medium mass and energy balancing equation based on mass and energy balancing; modifying an energy balancing equation in the step 4 according to heat storage change of a working medium and a metal heat-absorbing surface under the temperature pressure change; obtaining temperature, pressure and flow at each measurement point of the reheater system from the measurement point, and obtaining the temperature, pressure and flow related data of the working medium; simultaneously acquiring exhaust volumes of the primary exhaust and the secondary exhaust by combining the corrected mass and energy balancing equation; and finally obtaining the corrected reheater working medium flow.

The invention particularly discloses a steady-state analysis-based method for measuring a hemispherical total emissivity and a heat conduction coefficient. The steady-state analysis-based method comprises the following steps of: obtaining a long and thin belt-shaped conductor material sample, electrifying in a vacuum environment for heating, selecting one section of region at the middle as a test region, establishing a steady-state energy-balance equation according to a steady state calorimetric method; respectively indicating the hemispherical total emissivity and the heat conduction coefficient as mathematical functions about temperatures; carrying out multiple groups of steady-state measurement experiments under different steady-state temperature conditions so as to construct a steady-state energy-balance equation under different steady-state temperature conditions; and solving a to-be-confirmed parameter in the equation, and determining the hemispherical total emissivity and the heat conduction coefficient of the sample under different steady-state temperature conditions. The steady-state analysis-based method is suitable for measuring the hemispherical total emissivity of various conductor materials in the case that the heat conduction coefficient is unknown, and is also capable of obtaining the heat conduction coefficient of the conductor material so as to avoid the uncertainty influence caused by the unknown heat conduction coefficient to the measurement of the hemispherical total emissivity.

The invention provides a transient energy response high-precision prediction method for a complex construction. The method comprises the steps of taking time-varying items of energy transfer among subsystems into account, establishing a transient power balance equation of all the subsystems of the structure by combining a loss factor matrix eta of a complex structure, giving an initial boundary parameter, and adopting a fourth-order-fifth-order Runge-Kutta algorithm to calculate to obtain transient energy response of all the subsystems of the structure. Compared with a traditional method whichonly takes time-varying items of energy into account, according to the transient energy response high-precision prediction method for the complex construction, the more complete transient energy balance equation of all the subsystems of the complex structure by taking the time-varying items of the energy transfer among all the subsystems of the complex structure into account, the prediction precision in transient energy response prediction of a current transient statistics energy analysis method is obviously improved, the research range of the current transient statistics energy analysis method is expanded, transient energy response analysis of structures of different coupling strengths can be solved, commercial statistics energy analysis software is combined at the same time, and the transient energy response prediction problem of the complex structure can be solved.