Method of determining flow rates in the channels npu
The invention relates to measuring technique and can be used to determine flow rates in the channels of nuclear power plants in the measurement of flow through the turbine flow meters of various types. In the method of flow measurement converts rotary motion of the turbine flow meter in the system of electrical impulses. Create an output signal through a survey of the formed system of electrical impulses with a frequency above the limit f>fCRdetermine the number of pulses during the exposure, determine the coolant flow on the basis of previously obtained according to G (n), where fCR- limit frequency; n is the number of pulses measured during exposure, with frequency fAveThe technical result is an increase in the accuracy of determination of the flow. 2 Il., 1 PL.The invention relates to measuring technique and can be used to determine flow rates in the channels of nuclear power plants in the measurement of flow through the turbine flow meters of various types.There is a method of flow measurement consists in measuring the confused who entrusted the dependences G = f(P), where G is the measured flow,P - pressure drop across the constriction device (B. N. Preobrazhenskaya. Thermal measurements and instruments. M: Energy, 1978, S. 434).The main disadvantage of this method is that when measured by this method is difficult to place a narrowing device in large diameter pipes (channels NPU) and output the pulse tube to the datalogger. When installing an orifice in the channel are large pressure loss.The closest in technical essence and the achieved result is a way of measuring the flow, namely, that converts rotary motion of the turbine flow meter in the system of electrical impulses that create an output signal by generating a pulse of constant duration, convert it into a current signal, integrating the current signal during the exposure time and determine flow based on pre-obtained according to flow from the output signal G = f(I) (H. A. Dollezhal, I. Y. Emelianov. Channel nuclear power reactor. M: Atomizdat, 1980, S. 140). This method of flow measurement is currently used for measuring the flow in the channels of RBMK. In car-32M and SHADR-8A known and described in (A. H. Dollezhal, I. Y. Emelianov. Channel nuclear power reactor. M: Atomizdat, 1980, S. 140). Let us dwell on the disadvantages of the method relating to the removal of the signal and the actual definition of consumption. In Fig.1 shows a diagram that implements the method.The main disadvantage of this method is that the accuracy of the flow rate is small. The main error of each measurement channel error due to an error of Shadr and the Tiber. If the first one has a narrow dynamic range and S-shaped nonlinearity of the transformation, the second is the error associated with the nonlinearity of 1/S. Increase measurement error and subsequent units of the national Park and the ISU. In addition, there is also a dynamic component of error determined by the smoothing function of the Tiber and converting the analog signal into a digital code. In addition, over time the output signal of the MIP decreases in amplitude, which is associated with degradation parameters working together Ivan Shadr and MIP. Wear and deformation of the ball lead to fluctuations in the rotational speed at a constant flow. All this leads to a change in the originally received calibration characteristics of the form G=f(I), and change harale be different from the actual.The technical result, which is aimed invention is to improve the accuracy of determining the flow rate of the coolant that is provided by the fact that create an output signal through a survey of the formed system of electrical impulses with a frequency above the limit f > fCRdetermine the number of pulses during the exposure, determine the coolant flow on the basis of previously obtained according to G (n), where fCR- limit frequency; n is the number of pulses measured during exposure with frequency fCR.Direct use of a single value of n allows to exclude additional links, chains and conversion algorithms in the measuring channel and associated errors.Limit frequency fCRis determined on the basis of the analysis of the electrical pulses at the output of magnetic induction converters.In Fig.2 shows the structural scheme of the measuring system to control the flow of water, which implements the proposed method.Structurally measuring system that implements the proposed method, Fig.2, consists of two identical independent subsystems, each serving half of the reactor. Each subsystem, Merov also evenly divided into three groups and treated in three independent devices.The method for determining the flow is as follows.The rotational movement of the turbine flow meter (SHADR-8A and (or) SHADR-32M) is converted into electrical pulses by using magnetic induction transducer MIP, create an output signal through a survey of the formed system of electrical impulses with a frequency above the limit f > fCR. The latter is achieved by using a comparator that converts the frequency signals into digital signals, which form the signal of the logical units in the register, if the time interval measurements were frequency signal of the MIP. If the signal from the MIP was absent, it generates a signal of logical zero. When generating the output signal is the only condition is that the number of measurement intervals per unit time exceed the maximum pulse repetition rate of the MIP at the maximum flow rate. In our case this condition is met if 50 time intervals per second. Counting pulses in a time interval is carried out by software in the computer, where is a matrix of control of water consumption, presented in a frequency format.As an example, consider the measurement of rashtrakuta with different values (different frequency pulses MIP) depending on the time of the survey. As can be seen from the table, the improved accuracy is achieved by increasing the measurement time, when taken several times and the values averaged. The averaging procedure is based on the assumption that the error due to random factors and tends to zero when averaged over a large ensemble of samples.The main error transducers is ±1,5%. Taking into account errors generate an output signal (table), the total error of the flow measurement will not exceed 2%. When using the known method of measuring the flow rate, which is currently used in nuclear power plants with RBMK, the error in the determination of the flow rate can reach up to 10%.Thus, the proposed technical solution by eliminating additional channels of the transducer and associated errors allows to improve the accuracy of flow in channels NPU.
ClaimsMethod of determining flow rates in the channels of the NPP, namely, that converts rotary motion of the turbine flow meter in the system of electrical impulses, wherein creating the output siprelay the number of pulses during the exposure, determine the flow rate of the coolant based on the previously obtained relation is G(n), where fCR- limit frequency, n is the number of pulses measured during exposure with frequency fCR.
FIELD: nuclear power engineering; shipboard nuclear power plants.
SUBSTANCE: proposed method for checking core of shipboard water-cooled nuclear power plant for condition includes measurement of reference-radionuclide specific beta-activity in primary coolant samples taken from running reactor followed by evaluation of core condition. Sample for evaluating core condition is taken downstream of ion-exchange filter under any operating conditions of reactor. Used as reference radionuclide is tritium. Such method makes it possible to check reactor core for condition under any of its operating conditions, including shutdown condition.
EFFECT: reduced dose rate suffered by attending personnel under poor tightness condition of cans.
FIELD: technological processes.
SUBSTANCE: invention is related to highly efficient liquid medium with distributed nanoparticles for cooling of nuclear reactor as main material, with which the nanoparticles are mixed, to method and device for preparation of liquid medium and to method of liquid medium leak detection. Highly efficient liquid medium is a liquid natrium as the main material, in which the previously treated nanoparticles are evenly distributed for removal of oxide film on surfaces of nanoparticles. As nanoparticles, at least superfine nickel particles are used in the quantity of at least 10 million-1. The methods of condition creation were developed, in which the nanoparticles do not have the oxide film on their surface. First, by removal of oxide film prior to mixing of nanoparticles with liquid natrium in atmosphere of hydrogen gas. Second, by removal of oxide film by means of addition and shaking of oxygen absorber before or after nanoparticles addition to liquid natrium. Third, by coating of nanoparticles surface with natrim atoms prior to creation of oxide film on their surface with the help of device, which consists of evaporating chamber, chamber of molecular beam and collector chamber, which are successively connected with each other. The prepared alternative liquid medium possesses high working characteristics at low cost.
EFFECT: addition of nanoparticles to mentioned liquid medium leads to sharp increase of light brightness.
20 cl, 9 dwg
FIELD: measuring devices, metallurgy.
SUBSTANCE: ultrasonic measuring converter contains a unit which consists of an ultrasonic generator and an oscillations transmitting block; it is designed to direct ultrasonic waves into a liquid metal through the oscillations transmitting block and to receive ultrasonic waves passing through a liquid metal. The oscillations transmitting block can include a wave guide component located near the ultrasonic generator and a moistened component contacting with a liquid metal. The moistened component or the whole oscillations transmitting block are made out of ferrite stainless steel, of aluminium alloy, with contents of aluminum of 70% or more, or out of copper alloy with contents of copper 50% or more.
EFFECT: upgraded accuracy of measurements due to increased ratio of acoustic pressure transmission owing to optimisation of acoustic relation in a moistened border of a division.
6 cl, 12 dwg
FIELD: physics; nuclear power.
SUBSTANCE: invention is intended for the control of tightness of steam and gas generators of ship nuclear engine installation on the stopped reactor, both at stationary pressure, and at carrying out of hydraulic trials. The method of tightness control of steam and gas generators of the ship nuclear engine installation with the water heat transfer medium under pressure includes sampling from each prestressly drained steam and gas generator on the stopped reactor and measuring of the content of tritium with the subsequent calculation of leaking quantity. Samplings of air moisture are performed from the pipe system of each steam and gas generator. Then tritium content in air of the pipe system of each steam and gas generator is determined. Before sampling, additional removal of water from pipelines of a contour of circulation of the drained steam and gas generators is performed. Sampling of moisture of air and determination of tritium content in air is performed with an interval of 24-48 hours.
EFFECT: increase of sensitivity of control method, possibility of earlier detection of steam and gas generator leakiness and possibility of determination quantity of leaking of the heat transfer medium of the first contour in specific steam and gas generator.
FIELD: physics; measurement.
SUBSTANCE: present invention relates to a system of taking samples from the atmosphere of a reactor containment of a nuclear process installation and a method of obtaining such a sample. The system of taking samples contains a pipe for taking samples, which enters the reactor containment and is connected to a low pressure system and an analysis system. There is a throttling device in front of the pipe for taking samples on the side of the gas, where it connects to the atmosphere in the reactor containment. The pipe for taking samples is a small pipe with nominal inner diametre of up to 15 mm, and is preferably in form of a capillary pipe with nominal inner diametre between 1 mm and 5 mm. When implementing the method of taking samples, low pressure is created in the pipe for taking samples, compared to pressure in the reactor containment. After the sample enters the pipe for taking samples, pressure in the pipe is limited.
EFFECT: possibility of taking a sample, suitable for taking exceptionally reliable and accurate measurement values.
22 cl, 3 dwg
SUBSTANCE: invention relates to methods of controlling coolant of a nuclear reactor and can be used for approximating temperature field of working medium in heat exchangers and reactors. In the proposed method required local mass flow of a tracer in the working medium is determined after each elementary area at the inlet of the working section. The tracer is successively let into each elementary area at the inlet of the working section. An air sample is taken at the outlet of the working section and local concentrations of the tracer at the outlet of the working section are measured, corresponding to inlet of the tracer into different elementary areas at its inlet. Standardised local concentrations of the tracer at the outlet of the working section are added and the resultant local concentrations are obtained. The unknown local temperature of the working medium at the outlet of a full-sized installation is determined from an approximate relationship, which takes into account the ratio of the linear scale of the working section with respect to the full-sized installation, complete heat flow at the inlet of the full-sized installation, flow of the tracer at the inlet and concentration of the tracer at the outlet of the working section, specific heat capacity of the working medium at the outlet of the full-sized installation, density and average speed of the working medium at the outlet of the full-sized installation and working section.
EFFECT: wider functional capabilities, increased accuracy, reduced labour input for determining temperature field at the outlet of a full-sized installation.
9 cl, 4 dwg
FIELD: nuclear engineering.
SUBSTANCE: invention relates to devices designed to cut cores from well walls or channels and can be used in nuclear engineering to cutting graphite cores from channel-type uranium-graphite reactor lining. Proposed device comprises bearing rod with rotary drive, tubular cutter, and tubular cutter rotation-and-feed mechanism. The latter consists of drive bevel gear interacting with hollow gear shaft and fixed sleeve with outer thread arranged inside said hollow gear shaft. Note here that tubular cutter represents a sleeve with inner thread screwed on aforesaid fixed sleeve.
EFFECT: ease of cutting complete cores over entire width of graphite block at 90° to block location without using whatever means capable of destructing or fouling cores.
FIELD: power industry.
SUBSTANCE: invention is intended for determining thermal hydraulic characteristics (THC) along section of assembly and can be used for determining parametres of single-, double-phase flows in heat-producing assemblies of various purpose. A cell is taken in the check section of the assembly; difference of static pressures is measured till sample cell is formed on the wall of channel and on simulator of fuel elements on the side of cell under investigation. Sample cell is formed in check section by installing a sampler into the cell under investigation, which is identical as to the shape to the cell under investigation; difference of static pressures is measured after sample cell is formed. Sampling tube is connected to sample cell; pressure drop is measured between sample cell in check section and sampling section. Heat carrier is taken through the sampling tube, and THC are measured in the taken sample. At that, check section of assembly is chosen outside its active part, sample cell is pre-formed by installing a grid, and as the parametre characterising the cell state before and after sample cell is formed and sampling tube is connected, there used is total pressure in the cell centre.
EFFECT: improving measurement accuracy of thermal hydraulic characteristics along section of heat-producing assembly.
SUBSTANCE: proposed device comprises one vacuum chamber separated from controlled medium by hydrogen-permeable membrane and communicated with vacuum magneto-charged pump, as well as extra vacuum chamber separated from medium by hydrogen-permeable membrane and communicated with vacuum metre. Vacuum gate is connected between main and extra vacuum chambers. Controlled medium is fed to vacuum chambers by incoming flow head. Recuperator is used for heating purposes. Hydrogen concentration in circuit is controlled is performed by intermittent comparison of magneto-charged pump current readings with those of vacuum metre.
EFFECT: uptightness control in initial period.
2 cl, 2 dwg