RU2079112C1 - Process of determination of volume of substance in closed vessel and device for its implementation - Google Patents

Abstract

FIELD: food processing, pharmaceutical and other industries. SUBSTANCE: invention is intended for those branches of industry where it is necessary to determine amount of liquid, loose and solid substances stored in closed vessels. In process of determination of volume of substance vessel is pressurized up to subcritical ratio of pressures, pressure in vessel, of ambient atmosphere and temperature in vessel are measured end flow of air through nozzle with inconstant rate into atmosphere is checked by timer and positive pressure transducer. Volume of substance in vessel is found by gas and dynamic relationships. EFFECT: increased authenticity of process and device. 5 cl, 3 dwg

Description

 The invention relates to measuring equipment and can be used in food, pharmaceutical, processing and other industries where it is necessary to determine the amount of liquid, bulk and solid substances in a closed container.

 A known method and device for determining the volume of a substance in a closed tank, based on the creation of a dynamically changing overpressure in the reference and measuring tanks, separated from each other by an elastic impermeable membrane, an oscillating electromechanical drive with known parameters, recording the characteristics of the dynamic change of overpressure by two pressure sensors, one of which is installed in the reference, the other in the measuring capacities, and comparing the characteristics of the dynamic change d Aviation in the reference and measured capacities in a special comparison unit. The measurement accuracy in this case depends on the influence on the measurement results of the instability and non-linearity of the characteristics of the membrane, exciting dynamic pressure changes, as well as the non-linearity of the structural elements.

 There is a method of determining the volume of a substance in a tank and a device for its implementation, carried out by pressurizing the reference and measured containers with air with overpressure and its subsequent expiration from each container with supercritical expiration from the nozzle with a constant air flow rate and measuring the pressure drop time in containers with a fixed value . The disadvantage of this method and device is the need for two reference and measured capacities, the geometric dimensions of which must be equal or comparable. The ratio of the volume of capacities has a decisive effect on the accuracy of measurement. In addition, it is necessary to ensure a supercritical regime of outflow from the nozzle, which requires the creation of a high level of pressurization of containers, thereby creating great difficulties for the safe operation of the plants. The high required level of overpressure also introduces an additional measurement error associated with elastic deformations of the tank structure.

 The closest in technical essence and the problem to be solved is a method and apparatus for measuring the amount of a substance in a closed container. The method includes pressurizing the tank and measuring the parameters of the outflow of air from the tank at a constant flow rate.

 The device comprises means for supplying air with excessive pressure to the container, means for expelling air from the container with constant flow rate, a flow meter, a timer, and an overpressure sensor in the container. The need to ensure and maintain a constant air flow rate when it flows out of the tank requires a sufficiently high level of excess air pressure in the tank, which should provide a subcritical flow regime, in addition, a sufficiently large free volume of the measured quantity of substance is required to maintain a constant air flow rate from it to for some time.

 The technical problem solved by the invention is to increase the accuracy of determining the amount of a substance in a closed container, while ensuring operational safety by reducing the amount of excess air pressure.

 The stated technical problem is solved in that the main pressurization of the vessel is carried out to an overpressure at which the ratio of atmospheric pressure to the excess in the vessel is more than critical, then the main pressurization is stopped, while measuring the excess pressure and temperature in the vessel and the pressure in the atmosphere, and subcritical is carried out through the nozzle the outflow of air with a variable flow rate into the atmosphere, after which, over a fixed period of time, the excess pressure drops again measure the excess pressure in it bones and judge the volume of the substance by the ratio.

где
W_В объем вещества в замкнутой емкости, (м³);
W_Е объем замкнутой емкости без вещества, (м³);
τ_i интервал времени падения при открытом сопле избыточного давления в емкости от давления наддува P₁ до значения P_i, (с);
n показатель политроны процесса расширения воздуха в емкости:
f эффективная площадь сечения сопла, (м²);
R газовая постоянная воздуха, (R 29,27 кгм/кг•град);
T₁ температура воздуха при давлении наддува P₁ (K);
z_i-Z₁ изменение интегральной функции дозвукового истечения воздуха из емкости;
P₁ давление наддува емкости воздухом, (бар);
P_i давление воздуха в емкости по истечении интервала времени τ_i, (бар);
P_a атмосферное давление (бар);
ψ_i функции расхода воздуха из емкости;
K показатель адиабаты для воздуха (k 1,25);
В частных случаях, когда емкость, в которой находится вещество, негерметична, перед основным наддувом осуществляется тарировочный наддув избыточным давлением, величина которого равна давлению основного наддува, изменяя при этом избыточное давление и температуру в емкости и атмосфере, после чего через фиксируемый промежуток времени при падении избыточного давления в емкости за счет ее негерметичности, повторно измеряют избыточное давление в ней и судят о объеме вещества в негерметичной емкости по соотношениям.

Where
W _{In the} volume of the substance in a closed container, (m ³ );
W _{E is the} volume of a closed container without substance, (m ³ );
τ _i the time interval of the fall with an open nozzle of excess pressure in the tank from the boost pressure P ₁ to the value of P _i , (s);
n indicator of the polytron process of expansion of air in the tank:
f effective nozzle cross-sectional area, (m ² );
R gas constant of air, (R 29.27 kgm / kg • hail);
T ₁ air temperature at boost pressure P ₁ (K);
z _i -Z ₁ change in the integral function of the subsonic air flow from the tank;
P _{1 the} pressure of the pressurization of the tank with air, (bar);
P _i the air pressure in the tank after a time interval τ _i , (bar);
P _a atmospheric pressure (bar);
ψ _i functions of the air flow from the tank;
K is the adiabatic exponent for air (k 1.25);
In special cases, when the container in which the substance is located is leaky, a gauge pressurization is carried out before the main pressurization, the magnitude of which is equal to the pressure of the main pressurization, while changing the excess pressure and temperature in the container and the atmosphere, and then after a fixed period of time when falling excess pressure in the tank due to its leakage, re-measure the excess pressure in it and judge the volume of the substance in the leaky tank according to the ratios.

где
W_В объем вещества в замкнутой емкости, (м³;
W_Е объем замкнутой емкости без вещества, (м³);
τ_i интервал времени падения избыточного давления в емкости от давления наддува P₁ до значения P_i при открытом сопле (с);
τ_iт интервал времени падения избыточного давления в емкости от давления наддува P₁ до значения P_i при закрытом сопле (с);
n показатель политропы процесса расширения воздуха в емкости;
f эффективная площадь сопла (м²);
R газовая постоянная воздуха (R 29,27 кгм/кг•град);
T₁ температура воздуха в емкости при давлении наддува P₁ (K);
Z_i-Z₁ изменение интегральной функции дозвукового истечения воздуха из емкости;
P₁ давление наддува емкости воздухом, (бар);
P_i давление воздуха в емкости по истечении интервалов времени тау_i при открытом сопле, τ_iт при закрытом сопле, бар;
P_a атмосферное давление, (бар);
ψ_i Функция расхода воздуха из емкости;
K показатель адиабаты для воздуха, (k=1,25).

Where
W _{In the} volume of the substance in a closed container, (m ³ ;
W _{E is the} volume of a closed container without substance, (m ³ );
τ _i the time interval of the fall of excess pressure in the tank from the boost pressure P ₁ to the value of P _i when the nozzle is open (s);
τ _is the time interval for the fall of the overpressure in the tank from the boost pressure P ₁ to the value of P _i with a closed nozzle (s);
n polytropic indicator of the process of expansion of air in the tank;
f effective nozzle area (m ² );
R gas constant of air (R 29.27 kgm / kg • hail);
T _{1 the} temperature of the air in the tank at a boost pressure P ₁ (K);
Z _i -Z ₁ change in the integral function of subsonic air flow from the tank;
P _{1 the} pressure of the pressurization of the tank with air, (bar);
P _i the air pressure in the tank after the time intervals tau _i with the nozzle open, τ _it with the nozzle closed, bar;
P _a atmospheric pressure, (bar);
ψ _i Function of air flow from the tank;
K is the adiabatic exponent for air, (k = 1.25).

 In particular cases, in order to further increase the accuracy of changes in a single pressurization, the volume of the substance for various pressure drop values is repeatedly determined and the volume of the substance is judged as the average value of the calculated volumes for different values of the pressure drop.

 A device for determining the volume of a substance in a closed container contains elements for loading and unloading the substance from the container, means for supplying air with excess pressure to the container, means for flowing out of the container of air with excess pressure into the atmosphere in the form of a nozzle closing with a lid, a timer for the expiration of air with excess pressure from the tank, an overpressure sensor in the tank, an atmospheric pressure sensor outside the tank, an air temperature sensor in the tank and a calculator including the first connected in series a multiplier, the first input of which is connected to the temperature sensor in the tank, and the second to the constant signal adjuster proportional to the gas constant of air, the first exponential function calculation unit, the second multiplier, the second input of which is connected to the constant signal adjuster, proportional to the value of the polytropic coefficient of air expansion in capacitance, and the third input with a timer for the time of the expiration of air from the container, the first divider, a memory unit, the second divider, the first adder, the second input of which is connected to a constant sensor, a third divider, a second adder, the second input of which is connected to a signal generator proportional to the volume of a closed container without substance, and an output with a volume indicator of a substance in a closed container, as well as a third adder connected in series, to the first input of which a signal proportional to a constant and to the second input a signal proportional to the value of the polytropic exponent of air expansion in the tank, the fourth divider, the second input of which is connected to the output of the third multiplier, to the first One of which receives a signal proportional to the value of the polytropic exponent of air expansion in the tank, and to the second signal proportional to the constant, as well as a fifth divider connected in series, the first input of which with an overpressure sensor in the tank, and the second with an atmospheric pressure sensor, the second exponential calculation unit functions, the second input of which is connected to the output of the fourth divider, the fourth multiplier, the output of which is connected to the second input of the first divider, as well as a constant memory block, the first a branching input which is connected to an overpressure sensor in the vessel, a second control input with an atmospheric pressure sensor, a third control input with a constant signal adjuster proportional to the polytropic expansion coefficient of the air in the vessel, the output of the constant memory unit is connected to the second input of the fourth multiplier, and the fifth multiplier , the first input of which is connected to the memory unit, and the second input with a constant signal generator proportional to the effective area of the nozzle, and the output to the second input of the third elitelya.

 The solution to the constant problem is ensured by the fact that it is necessary to create a slight, practically safe overpressure in the tank, and widely used pressure sensors and serially produced elements are used.

 The invention provides automation of the measurement and calculation process to determine the amount of a substance in a closed tank or their systems.

 In FIG. 1 shows a device for determining the amount of a substance in a closed container; figure 2 its electronic circuit; figure 3 diagrams of various modes and possible options for operation.

A device for determining the amount of substance in a closed container includes (Fig. 1A) a container in the form of a housing of the hopper 1 with a known volume W _e ; in which an unknown amount of W _{B of the} measured substance is located 2. The part of the container that is not occupied by the substance is the free volume W _c 3, and the surface of the substance in the container has a complex spatial shape with arbitrary depressions and protrusions. A line 4 is mounted on the tank, overlapping by a valve 5 with an electro-pneumatic valve, for loading a measured amount of a substance; a nozzle with a subcritical expiration mode with a variable flow rate 6, which closes with a cover 7 for the time of capacity charging; means for supplying excess pressure air to the tank in the form of a pipe 8 with a valve 9; an element for unloading the substance from the tank in the form of a hatch 10. Inside the free volume of the tank, an overpressure sensor 11, an air temperature sensor are mounted 12. Outside the tank, there is an atmospheric pressure sensor 13 and a timer 14 for the outflow of air with excess pressure from the tank to the atmosphere.

 The calculator (Fig. 2) includes a series-connected first multiplier 15, the first input of which is connected to the temperature sensor 12, and the second to the sensor 16 of a constant signal proportional to the gas constant of air, the first exponential function calculation unit 17, the second multiplier 18, the second the input of which is connected to a constant signal master 19 proportional to the value of the polytropic expansion of air, and the third input with a timer 14, the first divider 20, the memory unit 21, the second divider 22, the first adder 23, the second input of which is connected to the constant generator 24, the third divider 25, the second adder 26, the second input of which is connected to the signal generator 27, which is proportional to the volume of the empty tank, and the output with the indicator 28 of the volume of the substance in the tank, as well as the third adder 29 connected in series, the first input of which is supplied by a signal from the constant generator 24, and the second input from the setter 19, and the fourth divider 30, the second input of which is connected to the output of the third multiplier 31, the first input of which is supplied by the signal from the setter 19, and to the second the th signal from the constant adjuster 32, as well as the fifth divider 33 connected in series, the first input of which is connected to the overpressure sensor 11, and the second to the atmospheric pressure sensor 13, the second exponential function calculation unit 34, the second input of which is connected to the output of the fourth divider 30 and the fourth multiplier 35, the output of which is connected to the second input of the first divider 20, as well as the memory unit 36, the first control input of which is connected to the gauge 11 of the overpressure, the second control input to the sensor 13 is atmospheric about pressure, and the third control input with a constant signal master 19, the output of the memory unit 36 is connected to the second input of the fourth multiplier 35, as well as the fifth multiplier 37, the first input of which is connected to the memory block 21, and the second input with the constant signal master 38, proportional to the effective area of the nozzle, and the output of the multiplier 37 is connected to the second input of the third divider 25.

где W_B объем вещества в замкнутой емкости, м³;
W_E объем замкнутой емкости без вещества, м³;
τ_i интервал времени падения избыточного давления в емкости от давления наддува P₁ до значения P_i при открытом сопле, с;
n показатель политропы процесса расширения воздуха в емкости;
f эффективная площадь сечения сопла, м²;
R газовая постоянная воздуха (R 29, 27 кгм/кг•град);
T₁ температура воздуха в емкости при давлении наддува, К;
Z_i-Z₁ изменение интегральной функции дозвукового истечения из замкнутой емкости;
P₁ давление наддува емкости воздухом, бар;
P_i давление воздуха в емкости по истечении интервала времени тау_i, бар;
P_a атмосферное давление (бар);
ψ_i функция расхода воздуха из емкости;
K показатель адиабаты для воздуха, (k=1,25);
В частном случае при наличии негерметичности в емкости способ предусматривает проведение перед основным наддувом тарировочного до давления, равного давлению основного наддува P₁. После прекращения тарировочного наддува измеряются избыточное давление и температуру воздуха в емкости T₁ и давление в атмосфере P_a, зачем через фиксируемый интервал времени падения избыточного давления τ_iт при закрытой крышке сопла за счет негерметичности емкости при докритическом истечении воздуха с непостоянным расходом повторно измеряют избыточное давление в ней P_i и после проведений всех операций основного наддува судят об объеме вещества в негерметичной емкости по соотношениям.The method of determining the volume of a substance in a closed container is as follows. Free from substances volume container with the lid closed nozzle nadduvayut excess air pressure P ₁ at which the atmospheric pressure ratio P _a to excess in the tank exceeds the critical, then stopped supercharging measured excess pressure in the container, the temperature therein T _1, the atmospheric pressure P and _a is carried out by opening the lid of the nozzle subcritical air outflow through a nozzle with a variable flow rate to the atmosphere, and then after a time fixed by timer τ _i repeatedly measured excess pressure P _i in the container and calculate the volume of material in the vessel by the relations:

where W _{B is the} volume of the substance in a closed container, m ³ ;
W _{E the} volume of a closed container without substance, m ³ ;
τ _i the time interval of the fall of excess pressure in the tank from the boost pressure P ₁ to the value of P _i when the nozzle is open, s;
n polytropic indicator of the process of expansion of air in the tank;
f effective nozzle cross-sectional area, m ² ;
R gas constant of air (R 29, 27 kgm / kg • hail);
T _{1 the} temperature of the air in the tank at a boost pressure, K;
Z _i -Z ₁ change in the integral function of subsonic outflow from a closed tank;
P _{1 the} pressure of the pressurization of the tank with air, bar;
P _i the air pressure in the tank after a time interval tau _i , bar;
P _a atmospheric pressure (bar);
ψ _{i is the} function of air flow from the tank;
K is the adiabatic exponent for air, (k = 1.25);
In the particular case of the presence of leaks in the tank, the method provides for carrying out calibration before the main boost to a pressure equal to the pressure of the main boost P ₁ . After stopping the calibration pressurization, overpressure and air temperature in the tank T ₁ and atmospheric pressure P _a are measured, why, over a fixed interval of time the drop in overpressure τ _it with the nozzle cover closed, due to leakage in the container at subcritical outflow with variable flow rate, overpressure is measured again in it P _i and after carrying out all the operations of the main pressurization, the volume of the substance in the leaky container is judged by the ratios.

где
W_b объем вещества в замкнутой емкости (м³);
W_e объем замкнутой емкости без вещества (м³);
τ_iт интервал времени падения избыточного давления в емкости от давления наддува до значения P_i при открытом сопле (с);
τ_i интервал времени падения избыточного давления в емкости от давления наддува до значения P_i при закрытом сопле (с);
n показатель политропы процесса расширения воздуха в емкости;
f эффективная площадь сечения сопла (м²).

Where
W _{b the} volume of the substance in a closed container (m ³ );
W _{e the} volume of the closed container without substance (m ³ );
τ _is the time interval for the fall of excess pressure in the tank from the boost pressure to the value of P _i with an open nozzle (s);
τ _i the time interval of the fall of excess pressure in the tank from the boost pressure to the value of P _i with a closed nozzle (s);
n polytropic indicator of the process of expansion of air in the tank;
f effective nozzle cross-sectional area (m ² ).

R gas constant of air (R 29.27 kgm / kg • hail);
T _{1 the} temperature of the air in the tank at a boost pressure P ₁ (K); Z _i Z ₁ change in the integral function of subsonic outflow from a closed tank;
P _{1 the} pressure of the pressurization of the tank with air, (bar); P _i - air pressure in the tank after the time intervals tau _i with the nozzle open, τ _it with the nozzle closed, (bar);
ψ _{i is the} function of air flow from the tank;
K is the adiabatic exponent for air (k 1.25);
The choice of the values of the time intervals of the pressure drop when the air _flows from the tank to the atmosphere (τ _i and τ _it ) must satisfy the requirement for the vessel to have excess pressure above atmospheric pressure, for example, by pre-setting specific values for the pressure P ₁ and P _i . For an additional increase in measurements with a single boost, the volume of the substance is repeatedly determined for different values of the pressure drop and the volume of the substance is judged as the average value calculated for different values of the pressure drop.

где
W_b среднее значение величины объема вещества в емкости (м³);
W_Bi, W_Bj, W_Bk величины объемов вещества в емкости, определенные по приведенным выше соотношениям в процессе однократного наддува ее до давления P₁ и истечении из нее воздуха до значений избыточных давлений P_i > P_j > P_k, (м³);
m число измерений объема вещества в емкости при ее однократном наддуве.

Where
W _{b the} average value of the volume of the substance in the tank (m ³ );
W _Bi , W _Bj , W _{Bk the} volume of the substance in the tank, determined by the above ratios in the process of a single pressurization of it to a pressure P ₁ and the outflow of air from it to the values of excess pressures P _i > P _j > P _k , (m ³ ) ;
m the number of measurements of the volume of the substance in the tank with its single boost.

A device for determining the amount of substance in a container works as follows. An unknown amount of substance 2 is loaded into the known free volume W _{E of the} container 1 through the line 4 with the valve 5 open. At the same time, the valve 9 of the overpressure air supply pipe 8, the substance discharge door 10 and the nozzle cover 7 are closed.

In the particular case when the tank may be leaky, a calibration tank is charged before the main boost. At the same time, the valve 9 of the pipeline 8 for supplying air with excess pressure to the tank 1 is opened. The sensor 11 controls the boost pressure in the tank, upon reaching a certain value of the overpressure P ₁ at which the ratio of the atmospheric pressure P _a to the excess P _{1 is} more than critical (P ₁ ≈ 1.2 1.4 kg / cm ² ) a signal is sent to close the valve 9 of the pipeline 8. At the same time as the boost is stopped, the overpressure P _{1 is} measured by the sensor 11, the air temperature in the tank T _{1 by the} sensor 12, the atmospheric pressure P _{a by the} sensor 13, s timer 1 4, readings corresponding to a zero countdown are taken.

Subsequently, in the process of pressure drop in the tank due to its leakage when the nozzle 6 is closed by the cover 7, the timer 14 fixes the time of the overpressure drop in the tank from the value of P ₁ to a certain value of P _i . As a result, when carrying out calibration pressurization, electric signals are supplied to the input of the calculator corresponding to the values of overpressure in the tank P ₁ and P _i , the time of the overpressure drop in the tank from P ₁ and P _i due to its leakage τ _it , and the temperature in the tank T ₁ , atmospheric pressure P _a .

When conducting the main boost also opens the valve 9 of the pipe 8 for supplying compressed air to the tank. The sensor 11 controls the pressure value of the main boost, upon reaching a certain excess pressure equal to P ₁ , a signal is sent to close the valve 9 of the pipe 8. Simultaneously with the termination of the main boost, the excess pressure P _{1 is} measured by the sensor 11, the air temperature T _{1 by the} sensor 12, atmospheric pressure P _{a by} sensor 13, a timer corresponding to a zero countdown is taken from timer 14. After that, the cover 7 of the nozzle 6 is opened and a subcritical air supply is carried out through the nozzle with a variable flow rate into the atmosphere. The timer 14 fixes the time τ _{i the} pressure drop in the tank from the value of P ₁ to P _i . As a result, when a major boost input calculator supplied electrical signals proportional to the boost pressure vessel P _1, overpressure P _i, the time of incidence of overpressure in the container from P ₁ to P _i due to leak and flow through the nozzle τ _i temperature tanks T ₁ , atmospheric pressure P _a .

 The work of the components of the calculator during calibration and main boosts largely coincides and occurs as follows.

 Serially connected adder 29, to the first input of which a signal is proportional to the constant (+1), and the second input is a signal proportional to the degree of polytropic n, a divider 30, the second input of which is connected to the output of the multiplier 31, to the first input of which a signal is proportional the degree of polytropic n, the second input - a signal proportional to the constant (+2), provide the output of the degree value for the calculation unit of the exponential function 34. The procedure for calculating the degree values for the block 34 when conducting t rirovochnogo and basic turbocharging identical.

A memory block of constants 36 for controlling signals from gauges of excess 11 and atmospheric 31 pressures and a signal setter 19 proportional to the degree of polytropic n. The output of the memory block connected to the second input of the multiplier 35, according to the values of P ₁ , P _i , n, produces a signal proportional to the magnitude of the change in the integral function of the subsonic outflow from the tank through the nozzle (Z _i Z ₁ ). The operation of the constant memory unit during calibration and main boost pressures does not differ.

Порядок вычисления комплекса

при проведении тарировочного и основного наддувов совпадает.Serially connected divider 33, to the first input of which a signal is supplied from the overpressure sensor 11, and to the second input from the atmospheric pressure sensor 13, the exponential function calculation unit 34, the second input of which is connected to the output of the divider 30 and the multiplier 35, the output of which is connected to the second the input of the divider 20, provide the calculation of the complex

Complex calculation procedure

during calibration and main boost pressures.

поступающий на первый вход умножителя 18. На два остальных входа умножителя 18 поступают сигналы, пропорциональные показателю степени политропы n от задатчика 19 и времени падения избыточного давления в емкости за счет ее негерметичности τ_iт На выходе умножителя 18 имеет место сигнал, пропорциональный произведению

который поступает на первый вход делителя 20. На второй вход делителя 20 поступает сигнал от умножителя 35, пропорциональный комплексу

Аналогичный порядок вычислений реализуется после завершения процедуры основного наддува. В итоге на выходе делителя 20 в зависимости от вала наддува формируются сигналы, пропорциональные комплексам

которые поступают в блок памяти 21, последовательно соединенный с делителем 20.Upon completion of calibration pressurization, an electric signal corresponding to the temperature in the tank T ₁ is supplied to the first input of the multiplier 15, and the gas constant of air R is sent to the second from the setter 16. After the multiplier 15, a signal equal to the product RT ₁ is fed to the input of the exponential function calculation unit 17, at the output of which there is a signal proportional to

arriving at the first input of the multiplier 18. The other two inputs of the multiplier 18 receive signals proportional to the degree of polytropic n from the setter 19 and the time of the overpressure drop in the tank due to its leakage τ _it At the output of the multiplier 18 there is a signal proportional to the product

which goes to the first input of the divider 20. The second input of the divider 20 receives a signal from the multiplier 35, proportional to the complex

A similar calculation procedure is implemented after the completion of the main boost procedure. As a result, at the output of the divider 20, depending on the boost shaft, signals are proportional to the complexes

which enter the memory unit 21, connected in series with the divider 20.

. Этот сигнал поступает на первый вход последовательно подсоединенного сумматора 26, на второй вход которого поступает сигнал от задатчика 27 сигнала, пропорционального объему свободной от вещества емкости W_Е. Суммарный сигнал, соответствующий величине объема вещества в замкнутой емкости, поступает на индикатор 28.Next, the signals from the memory unit 21 are fed into a series-connected divider 22, generating a signal proportional to the ratio K _i / K _it , an adder 23, the second input of which is connected to the constant setter 24 (+1), generating a signal proportional to the value (1 K _i / K _it ), a divider 25, which, when interacting with a multiplier 37, has a first input connected to the memory unit 21 and a second input with a constant signal master 38 corresponding to the effective area of the nozzle f. As a result, at the output of the divider 25, a signal is generated proportional to the value of the complex

. This signal is fed to the first input of the series-connected adder 26, to the second input of which a signal is received from the signal setter 27, which is proportional to the volume of the substance-free tank W _E. The total signal corresponding to the value of the volume of the substance in a closed tank, is fed to the indicator 28.

Claims (4)

1. The method of determining the volume of a substance in a closed tank, based on the boost of the tank and measuring the parameters of the air outflow from it, characterized in that the main pressurization of the tank is carried out to an overpressure, at which the ratio of atmospheric pressure to the excess in the tank is more critical, then stopping the main pressurization, at the same time measure the excess pressure and temperature in the tank and the pressure in the atmosphere, after which subcritical air flow is carried out with a variable flow rate into the atmosphere through the nozzle and through after a time interval, the excess pressure in the container is re-measured and the volume of the substance in the container is determined by the ratios

where W _{In the} volume of the substance in a closed container;
W _{E is the} volume of a closed container without substance;
τ _i the fall time interval with an open nozzle of excess pressure in the tank from the boost pressure P ₁ to the value of P _i ;
n polytropic indicator of the process of expansion of air in the tank;
f effective nozzle cross-sectional area;
R gas constant of air;
T _{1 the} temperature of the air in the tank at a boost pressure P ₁ ;
Z _i Z ₁ change in the integral function of subsonic air flow from the tank;
P _{1 the} pressure of the pressurization of the tank with air;
P _i the air pressure in the tank after a time interval τ _i ;
P _a atmospheric pressure;
ψ _{i is the} function of air flow from the tank;
k is the adiabatic exponent for air. 2. The method according to p. 1, characterized in that when the process is carried out in an unpressurized container before the main pressurization, its calibration pressurization is carried out, the excess pressure and temperature in the container and the pressure in the atmosphere are measured, and then after a time interval when the overpressure in the container drops due to its leakage with a closed nozzle, the overpressure in it is re-measured and the volume of the substance in the leaky container is determined by the ratios

where W _{In the} volume of the substance in a closed container;
W _{E is the} volume of a closed container without substance;
τ _i the time interval of the fall of excess pressure in the tank from the boost pressure P ₁ to the value of P _i when the nozzle is open;
τ _is the time interval for the fall of excess pressure in the tank from the boost pressure P ₁ to the value of P _i with the nozzle closed;
n polytropic indicator of the process of expansion of air in the tank;
f effective nozzle cross-sectional area;
R gas constant of air;
T _{1 the} temperature of the air in the tank at a boost pressure P ₁ ;
Z _i Z ₁ change in the integral function of subsonic air flow from the tank;
P _{1 the} pressure of the pressurization of the tank with air;
P _i the air pressure in the tank after the time intervals τ _i when the nozzle is open, τ _it when the nozzle is closed;
ψ _{i is the} function of air flow from the tank;
k is the adiabatic exponent for air.  3. The method according to claims 1 and 2, characterized in that the volume of the substance is determined as the average value of the calculated volumes for different values of the drop in excess pressure with a one-time boost.  4. A device for determining the volume of a substance in a closed container, containing elements for loading and unloading the substance from the container, means for supplying air with excess pressure to the container, means for flowing out of the container of air with excess pressure, an overpressure sensor, and a timer for the time of expiration of air from the container characterized in that the means for the outflow of air with excess pressure from the tank is made in the form of a nozzle with a sealed cap with subcritical expiration at a constant flow rate, while the device is additional o contains an atmospheric pressure sensor, an air temperature sensor in the vessel and a calculator including a first multiplier connected in series, the first input of which is connected to the air temperature sensor in the vessel, and the second with a constant signal generator proportional to the gas constant of the air, the first exponential function calculation unit, the second input of which is connected to a constant signal generator proportional to the value of the polytropic exponent of air expansion in the tank, and the third input with a timer the volume of air outflow from the tank, the first divider, the memory block, the second divider, the first adder, the second input of which is connected to the constant generator, the third divider, the second adder, the second input of which is connected to the signal generator proportional to the volume of the closed tank without substance, and the output is an indicator of the volume of the substance in a closed container, as well as a third adder connected in series, to the first input of which a signal is proportional to the constant, and to the second input is a signal proportional to the value of the indicator olitropes of expansion of air in the tank, and a fourth divider, the second input of which is connected to the output of the third multiplier, to the first input of which a signal is proportional to the value of the polytropic exponent of air expansion in the tank, and to the second is a signal proportional to the constant, as well as a fifth divider connected in series the first input of which is connected to an overpressure sensor in the tank, and the second to the atmospheric pressure sensor, the second exponential function calculation unit, the second input of which is connected to the output the house of the fourth divider, and the fourth multiplier, the output of which is connected to the second input of the first divider, as well as a constant memory block, the first control input of which is connected to an overpressure sensor in the tank, the second control input with an atmospheric pressure sensor, and the third control input with a constant adjuster a signal proportional to the polytropic expansion coefficient of air in the tank, the output of the constant memory block is connected to the second input of the fourth multiplier, as well as the fifth multiplier, the first input of which is connected a memory unit, a second input with setpoint DC signal proportional to the effective area of the nozzle, and an output to a second input of the third divider.

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