SU1649278A1 - Method of defining gas consumption and device thereof - Google Patents

Abstract

The invention relates to a measurement technique and makes it possible to improve the accuracy of determining the amount of gas passed or charged into a container. Prior to the occurrence of consumption, the regulating element of the stabilizer 3 of the pressure differential takes the position that ensures the maximum possible gas flow rate for this device. When a gas flow occurs, the regulating element of the stabilizer 3 maintains the pressure differential across the pressure differential converter 2, not exceeding a predetermined value. Signals proportional to the differential pressure and volume flow are received at the inputs of the computational converter 4 — the mass flow is calculated. 2 sec. f-ly, 1 ill.

Description

The invention relates to measuring equipment, in particular to flow measurement, and can be used to create instruments for measuring the flow rate and amount of gaseous media in units of mass, including when filling gas into a container.

The purpose of the invention is to improve the accuracy of measurement.

The drawing shows a block diagram of a device for determining the amount of gas passing through the device, in units of mass.

The device comprises a volume flow converter 1, a differential pressure converter 2, a differential pressure stabilizer 3, a computing converter 4 with a constant value input unit 5, and an indicator in the form of a video terminal 6.

The implementation of the method is as follows.

Before the flow appears, the regulating element of the differential pressure stabilizer 3 automatically takes a position that ensures the maximum gas flow for this device. Further, when a flow occurs through the device, the differential pressure stabilizer 3 regulating element 3 controls the gas flow rate so that the differential pressure measured by the differential pressure transducer 2 between the input and the first output of the volumetric flow transducer 1 is maintained within a predetermined value.

The volumetric flow converter 1 converts the gas flow passing through it into an electrical output (e.g., pulse frequency) signal fQ proportional to the volumetric flow rate. The differential pressure transducer 2 converts the differential pressure that it perceives into a unified output current signal bp. The signals Γ · ψ and fa are fed to the inputs of the computing transducer 4. Before the device starts to work, the values of the calibration coefficient B, gas density under normal conditions p0, the settings for the start of refueling I ARy “and / or f Qy _H , as well as a number of other settings and parameters including zero offset values a, b of differential pressure and volume flow transducers. The calculation of the current value of the mass flow rate of gas is performed by the computing Converter 4 according to the formula _ B <Ar-s

Po fQ-b '

The calculation results are displayed on the screen of the video terminal 6. To eliminate the random component of the measured value of the current signal Up, the computing converter 4 performs mathematical filtering of the signal, and it is possible to increase the measurement accuracy by selecting the optimal value of the mathematical filter time constant for a particular device, including it after the end of the transition process, due to starting gas.

Using the invention allows to determine the flow rate and the amount of gas passed in units of mass with high accuracy, which is achieved by high accuracy of measuring the pressure drop and volumetric flow rate, as well as by reducing the influence of transients and random factors. The high accuracy of the differential pressure measurement is ensured by maintaining it close to a constant value near the upper measurement limit of the differential pressure transmitter 2. The flow rate limiting by the stabilizer 3 of the differential pressure, as well as the timely issuance of a command to close the shut-off valve 4, also favors the operation of the volume flow converter 1, since the range changes in volumetric flow through it is significantly limited.

Claims (2)

Claim 1. The method of determining the gas flow rate, including measuring the pressure drop across the hydraulic resistance and the volumetric flow rate, and calculating the ratio of these values, the value of which is used to judge the flow rate, characterized in that, in order to improve the measurement accuracy, the reference point of the transducers is adjusted before measurement differential pressure and volumetric flow rate, carry out the measurement, and after the end of the transition process due to the start of gas, average the output signal of the differential pressure transducer, while repad pressure on the meter volumetric flow rate is kept constant. 2. A device for determining a gas flow rate, comprising a volumetric flow rate transducer located in a measuring pipeline, the input and output of which is connected to the inputs of a differential pressure transducer, a computational transducer whose inputs are connected to the outputs of the volumetric flow and pressure transducer, and the output is connected to an indicator, characterized by the fact that a stabilizer is introduced into it and are switched respectively to the inlet and outlet of the differential pressure, the inputs of which are a measuring pipeline. Compiled by V. Yarych Editor E. Kopcha Tehred M. Morgenthal Corrector M. Demchik Order 1512 Circulation 434 Subscription VNIIIPI of the State Committee for Inventions and Discoveries under the State Committee for Science and Technology of the USSR 113035, Moscow, Zh-35, Raushskaya nab., 4/5 Production and Publishing Plant Patent ”, Uzhgorod, 101 Gagarina St.