35 results about "Chemical reaction model" patented technology

The invention relates to the technical field of diesel engine aftertreatment system control, and particularly discloses a method for diagnosing abnormal concentration of a urea solution of an SCR system. The method comprises the steps that whether an enabling condition is met or not is detected; when the enabling condition is met, integral operation is carried out on upstream and downstream NOx sensor measurement values of the SCR system, and meanwhile integral operation is carried out on an NOx value calculated by an SCR chemical reaction model; according to the result of integral operation on the upstream NOx sensor measurement value of the SCR system, whether the accumulated value of the SCR upstream NOx mass flow exceeds a preset threshold value or not and whether the accumulated timeexceeds preset time or not are judged; if the accumulated value of the SCR upstream NOx mass flow exceeds the preset threshold value and the accumulated time exceeds the preset time, the difference value between the accumulated value of the SCR upstream NOx sensor mass flow and the accumulated value of the mass flow calculated by the SCR chemical reaction model is calculated; and according to whether the difference value exceeds a preset difference value or not, whether the concentration of the urea solution of the SCR system is abnormal or not is judged. According to the method for diagnosingabnormal concentration of the urea solution of the SCR system, diagnosis of abnormal concentration of the urea solution can be achieved.

The invention provides a method for estimating activity of a catalyst in a denitration device of a coal-fired boiler. The method is characterized in that in the activity estimation process, the online operation parameters and data of a data collecting system are utilized, the catalyst periodic test data and the denitration process and structure parameters are combined, a chemical reaction model in the denitration process is used for estimating the denitration efficiency, and the activity of the denitration catalyst is estimated according to the denitration efficiency; if the activity of the catalyst is in the activity deactivating area (about 50%), a catalyst replacement plan is considered; for the catalyst replacement plan, the local catalyst activity condition is obtained according to the nitrogen oxide concentration distribution estimation, ammonia spraying accumulation computing, design parameters of a denitration system, and equivalent methods, and a to-be-replaced area is determined. A local replacement plan for the catalyst activity estimation model is favorable for improving the utilization efficiency of the catalyst, the cost is reduced, and the service life of the denitration catalyst of a thermal power plant is prolonged.

The invention relates to a measuring method of kinetic parameter change rules of an after-service SCR (selective catalytic reduction) denitrification system catalyst, which comprises the following steps: establishing an SCR catalyst activity detection experiment table, cutting off a test sample block from the whole in-service catalyst block in site, putting the test sample block in a reactor, and setting experimental parameters for all experiments, including reactor internal temperature, experiment gas introduction amount and ammonia-nitrogen ratio; and simulating the chemical reaction process of the in-service SCR denitrification system catalyst, establishing a chemical reaction model of the catalyst in the reactor, calculating the kinetic parameters of the catalyst, and fitting to obtain a kinetic parameter change rule curve chart for predicting the kinetic parameter change rules of the catalyst. The technique provided by the invention can provide technical support for establishment of a power plant SCR denitrification system operation regulation scheme.

The invention relates to a modeling method for a dynamic mechanism model of alkyl aromatics liquid-phase oxidation. The invention is based on a free radical chain type reaction mechanism, simplifies the reaction path of alkyl aromatics liquid-phase oxidation, builds the dynamic mechanism model of alkyl aromatics liquid-phase oxidation, utilizes an internal mapping Newton method and iterates the adoption of conjugate gradient method for pretreatment every time to estimate parameters with which the dynamic model is involved, so as to realize the correct fitting and prediction of the model for actual data. The modeling method simplifies a chemical reaction model of alkyl aromatics liquid-phase oxidation, decreases model parameters, reduces the difficulty of estimating parameters, and provides convenience for industrial application. Moreover, the model has higher precision of fitting and predicting experimental data, thereby having good practicality. In addition, the modeling method is applicable to build the dynamic models of alkyl aromatics liquid-phase oxidation in different species, which has extensive applicability.

The invention relates to a simulation prediction method for PEMS emission of a whole vehicle based on universal characteristics of an engine. The method comprise: carrying out coupling control on a CRUISE whole vehicle model, a postprocessor BOOST chemical reaction model, a urea injection control model, an engine pedestal and a whole vehicle postprocessor temperature difference model; constructinga PEMS road spectrum; exporting rotating speed torque information and actual environment information of the engine; performing interpolation processing to obtain original exhaust gas components, exhaust gas flow and exhaust gas temperature initial values of the PEMS road spectrum engine; carrying out transfer function processing to obtain optimized values of original exhaust gas components and exhaust gas flow of the engine; correcting the processor temperature; and calculating exhaust gas components and exhaust gas flow data at the outlet of the SCR catalyst, and the ammonia storage capacityand the urea injection capacity of the SCR catalyst. According to the method, the engine emission development test cost can be reduced, the project development period can be shortened, and the simulation prediction speed and precision are improved.

The invention belongs to the technical field of oil and gas field development, and provides a method for evaluating the influence of carbon dioxide flooding salt deposit precipitation on recovery efficiency. On the basis of theoretical analysis and experimental research on salt deposit precipitation caused by CO2 flooding, a one-dimensional numerical model is established by using numerical simulation software, and a core CO2 flooding experiment is simulated. By using a chemical reaction model, the influence of salt deposit precipitation on the core in the CO2 flooding process is considered. Parameters are continuously adjusted in the numerical model, and correction is carried out by using a physical model experiment result. A one-dimensional model of salt deposit precipitation in the CO2 flooding process suitable for a research sample is established, and the influence of salt deposit precipitation on the final recovery efficiency is analyzed. Therefore, whether the influence of salt deposit precipitation needs to be considered in subsequent recovery efficiency prediction can be determined, recovery efficiency prediction is facilitated, and the accuracy of prediction is improved.

The invention discloses an interactive yield optimization method and system based on a recurrent neural network, belongs to the technical field of chemical reaction yield optimization, and aims to solve the technical problem of how to obtain a relatively high chemical reaction yield on the premise of reducing the experiment cost. Comprising the following steps: acquiring various experimental condition parameters; simulating a current chemical reaction through a mixed Gaussian density function to obtain a reaction yield; constructing a chemical reaction model based on the recurrent neural network model; and initializing a historical data set, training the chemical reaction model by taking the encoded experimental condition parameters and the corresponding chemical reaction yield as current experimental condition parameters and corresponding reaction yield, outputting experimental condition parameters of the next round as target experimental parameters, and performing a chemical experiment based on the target experimental condition parameters. The obtained reaction yield is used as a target reaction yield; and under the condition that the target reaction yield reaches a threshold value, carrying out multiple rounds of training on the chemical reaction model.

The invention relates to a thermochemical unbalanced flow field data calculation method and device utilizing GPU acceleration. The method comprises the following steps of: ; the method comprises the following steps: reading preset grid data, a chemical reaction model and an initial incoming flow condition through a CPU; storing in a global memory; the method comprises the following steps: readinggrid data and initial incoming flow conditions from a global memory through a GPU; grid point calculation in a preset flow field area is carried out; calculating a result and an initial incoming flowcondition according to the grid points; updating boundary conditions, reading a chemical reaction model from a global memory through a GPU (Graphics Processing Unit), calculating a chemical reaction source item according to the chemical reaction model and the initial incoming flow condition, iteratively calculating flow field data by the GPU according to the chemical reaction source item, a boundary condition and a preset flux calculation format, and storing the flow field data into the global memory by the GPU; and the CPU reads the flow field data from the global memory and outputs the flowfield data. By adopting the method, the flow field data calculation efficiency can be improved.

The invention discloses a method for constructing a microscopic reaction model in a polycrystalline silicon efficient deposition process, and the method comprises the following steps: a, constructing a microscopic distribution state of gas and a microscopic distribution state of atoms on the surface of a silicon rod; b, constructing a simulation box, and introducing gas into the simulation box to obtain a preliminary chemical reaction model; c, optimizing the chemical reaction model; d, fixing all atoms in a unit cell layer at the bottom end of the Si substrate in the chemical reaction model to complete the construction of the chemical reaction model. According to the invention, through a mode of fixing the Si unit cell layer, the problem that the Si substrate cannot keep a stable configuration at a high temperature and is easy to agglomerate is effectively solved; a Si substrate (Si supercell) is constructed in a mode of periodically repeating Si unit cells, and continuous and uninterrupted Si rod surface simulation is realized. The chemical reaction model construction method is suitable for the chemical vapor deposition process of polycrystalline silicon, and is also suitable for the gas-solid two-phase modeling process of other chemical vapor deposition processes.

The invention belongs to the field of numerical simulation of combustion disciplines, and relates to a method for simplifying a large-scale detailed chemical reaction model of high-carbon fuel. A large-scale detailed chemical reaction model of high-carbon fuel is simplified, and a simplified reaction kinetic model meeting multi-dimensional combustion simulation in terms of precision and scale at the same time is obtained. According to the method, a sub-model/reaction class is taken as an object to simplify the large-scale detailed chemical reaction model of high-carbon fuel, the number of input variables is greatly reduced, the calculation time of global sensitivity analysis is shortened, and application of the global sensitivity analysis to the large-scale detailed chemical reaction model becomes possible.