Provided is a method of the simulation construction for measurement of the control rod insertion time including a three-dimensional modeling operation of an inside wall of the nuclear reactor, a control rod, etc; a flow field configuration operation wherein the flow field is differentially configured by a variable grid system comprising variable cells which change the configuration and by an aligned grid system comprising fixed cells which maintains the configuration; a calculation operation of simulation estimated value for the insertion time by analyzing the thermal-hydraulic phenomenon using the three-dimensional CFD; and a cell change operation, wherein an error between the estimated value and the actual value is verified whether the error lies within the reference range, and, when the error exceeds the reference range, the size of the variable cell and/or of the size of the fixed cell is changed.

An actuator is provided that includes a housing, a linear actuating shaft disposed within the housing, a piston coupled with the shaft, and a fluid barrier disposed on an end of the shaft and encircled by the piston. The piston is movable longitudinally between an extended configuration and a retracted configuration upon rotation of the shaft. The fluid barrier engages an inner surface of the piston preventing fluid communication across the fluid barrier. The fluid barrier has a shaft engaging side which receives the shaft and a fluid facing side. A cavity is formed between the piston and the fluid facing side and expands when the piston moves to the extended configuration and contracts when the piston moves to the retracted configuration. A port is disposed in the piston and extends from the cavity to external the piston thereby permitting fluid communication between the cavity and external the piston.

The present disclosure relates generally to methods and systems for achieving enhanced catalytic performance via the strategic arrangement of multiple catalyst beds in series, where each catalyst bed comprises a compositionally-distinct catalyst, and each catalyst facilitates the conversion of the same structural moieties on the reactant to form the same product. Arranging multiple catalyst beds according to the methods and systems disclosed herein allows a predictable enhancement of conversion of the reactant to product without the need for time-consuming experimentation to test all possible catalysts configurations.

Granular polysilicon is produced in a fluidized-bed reactor by fluidizing silicon particles by means of a gas flow in a fluidized bed heated to a temperature of 850-1100 C., adding a silicon-containing reaction gas by means of a nozzle and depositing of silicon on the silicon particles, wherein, in at least 56% of an axially symmetric region around a nozzle opening of the nozzle, the reaction gas concentration is greater than 75% of the maximum concentration of the reaction gas (10 to 50 mol %), the fluidized-bed temperature is greater than 95% of the fluidized-bed temperature outside the axially symmetric region (850-1100 C.) and the solids concentration is greater than 85% of the solids concentration at the edge of the fluidized bed (55 to 90% by volume).

A fluid dynamic model having at least 5,000,000 cells of the portion of a gas phase reactor from the exit of the condenser to a half a reactor diameter above the bed plate is useful in determining the design of the bottom surface or support structure for a bed plate to minimize liquid pooling below and above the bed plate when operating in condensing mode.

A method of determining a local temperature anomaly in a fluidized bed combustion boiler system that includes at least three temperature sensors together defining a measurement grid, each sensor representing a measurement point, includes monitoring current operation data of the boiler, including measured bed temperature and at least primary air flow, fuel moisture, main steam flow, flue gas oxygen, and bed pressure, preparing a numerical model among operation data, such as primary air flow, fuel moisture, main steam flow, flue gas oxygen, and bed pressure. The measured bed temperatures measurement points are prepared and calibrated. Bed temperatures for the measurement points are monitored using the numerical model. This obtains computed bed temperatures under normal operation conditions, and the measured bed temperatures are compared with the computed bed temperatures for at least some of the measurement points. If an anomaly threshold is exceeded, determining that a local temperature anomaly is present.

A method of determining a local temperature anomaly in a fluidized bed combustion boiler system that includes at least three temperature sensors together defining a measurement grid, each sensor representing a measurement point, includes monitoring current operation data of the boiler, including measured bed temperature and at least primary air flow, fuel moisture, main steam flow, flue gas oxygen, and bed pressure, preparing a numerical model among operation data, such as primary air flow, fuel moisture, main steam flow, flue gas oxygen, and bed pressure. The measured bed temperatures measurement points are prepared and calibrated. Bed temperatures for the measurement points are monitored using the numerical model. This obtains computed bed temperatures under normal operation conditions, and the measured bed temperatures are compared with the computed bed temperatures for at least some of the measurement points. If an anomaly threshold is exceeded, determining that a local temperature anomaly is present.

A process for operating a chemical process includes deriving coefficients for a process performance model from historical feed data and historical production data; formulating the process performance model using the coefficients; determining a predicted change in production of a product of the chemical process using the process performance model; and changing a processing parameter of the chemical process based on economic data and the predicted change in production of the product of the chemical process.

A method for the reduction of a metal oxide-containing material in which a reducing gas that is obtained using ammonia (NH.sub.3) is used. The reducing gas is supplied to a reduction reactor containing the metal oxide-containing material, and a top gas is discharged from the reduction reactor. At least one sub-quantity of the top gas is used as components in the preparation of the reducing gas, optionally after the top gas is prepared. A device for the reduction of the metal oxide-containing material that includes a reduction reactor, a top gas discharge line for discharging top gas, a supply line for an ammonia contribution, a preparation system for preparing the reducing gas, a supply line for the ammonia contribution leading into the preparation system, and a feed line for feeding the reducing gas and/or a precursor of the reducing gas to the reduction reactor.

Provided is a fuel-reforming device comprising: an ammonia tank (4); a reformer (5) for reforming ammonia and generating high-concentration hydrogen gas having a hydrogen content of at least 99%; a mixing tank (7) for mixing ammonia and hydrogen for temporary storage; and a control means (10) for controlling the respective supply amounts of ammonia and high-concentration hydrogen gas that are supplied to the mixing tank (7). The control means (10) calculates the combustion rate coefficient C of mixed gas with respect to a reference fuel on the basis of equation (1). Equation (1): S.sub.0=S.sub.HC+S.sub.A(1C). In equation (1), S.sub.0 is the combustion rate of the reference fuel, S.sub.H is the combustion rate of hydrogen, S.sub.A is the combustion rate of ammonia, and C is the combustion rate coefficient of mixed gas. In addition, on the basis of equation (2), the control means (10) determines the volume fractions of ammonia and hydrogen that are supplied to the mixing tank. Equation (2): C=1exp(AM.sub.B). In equation (2), M is the volume fraction of hydrogen in mixed gas, and A and B are constants.