KR101316332B1 - An energy measuring device using matrix typed database and the energy measuring method - Google Patents

Abstract

PURPOSE: A gas energy measurement apparatus and method using a matrix structure are provided to calculate enthalpy through a thermodynamic method with respect to gas mixture defined by users as well as all the gas existing on the Earth and to convert the calculated enthalpy into a database of a matrix structure, thereby calculating energy easily. CONSTITUTION: A gas energy measurement method comprises the steps of: building a database of a matrix structure for input constants depending on a type, pressure, and temperature of gas; building enthalpy depending on the type, pressure, and temperature of the gas into an enthalpy database of a matrix structure; inputting the type, temperature, pressure of the gas to measure, a pressure difference, the inlet diameter of a fastener energy measurement device, and the diameter of a throttle; selecting and inputting input constants depending on the type, temperature, pressure of the gas from the database of the matrix structure for the input constant depending on the inputted type of the gas; computing the coefficient of expansion by using an inputted adiabatic index, diameter ratio, and pressure ratio; and compensating a run-off coefficient. [Reference numerals] (AA) Start; (BB) Measuring target gas, T.P, dp, d, D; (CC) Select a proximity input constant of the range containing T.P in a input constant database and input a input coefficient through interpolation calculation process; (DD) Is there an input constant matching for the input constant database?; (EE) Is there enthalpy matching for T.P inputted in an enthalpy database of Measuring target gas?; (FF) Select an input constant in the input constant (x,μ,ρ) database and input; (GG) Coefficient of expansion ε calculating process; (HH) Run-off coefficient C revising process; (II) Measure gas flux through calculation process according to a gas flux measurement formula; (JJ) Select enthalpy in the enthalpy database and input; (KK) Measure energy by calculating measured gas flux and enthalpy; (LL) Output measured energy on the screen; (MM) End

Description

An energy measuring device using matrix typed database and the energy measuring method}

The present invention is to calculate the thermal insulation index, steam density, and viscosity coefficient in the gas flow meter using a tightening mechanism using the thermodynamic relationship equation to obtain the thermal insulation index, gas density, gas viscosity coefficient for each temperature and pressure condition Measure the flow rate of the gas using the method of simply correcting the gas expansion coefficient and the outflow coefficient, and also calculate the enthalpy using the enthalpy matrix structure according to the pressure and temperature of the gas to be measured, and then apply it. The present invention relates to a method for measuring energy and an energy measuring device for a gas using the same.

The conventional calorie (or energy, Q) calculation is calculated using the temperature difference in the constant pressure specific heat state constant for mass flow rate, such as Q = mCp ΔT. This method was mainly applied to incompressible fluids with a gas expansion coefficient of 1. However, the conventional method is a compressible fluid as in the case of a real gas or a mixed gas, and the static pressure specific heat is not constant when the temperature and pressure of the gas change, so enthalpy (h) including internal energy should be applied.

In Q = mh, the enthalpy's internal energy has to calculate the equilibrium constant value such as the compression coefficient, but the calculation requires a large amount of computational memory and speed, and since the deviation factor must be applied, it is practical to calculate the enthalpy and calories. Very difficult. In addition, the conventional technique is impossible to measure the heat of gas when the mass ratio of each physical property of the mixed gas is changed. Therefore, conventional energy meters are used in extremely limited areas where physical properties such as incompressible fluids or steam or air are possible. In addition, since the gas energy cannot be measured, the amount of energy is calculated by exchanging heat with an incompressible fluid. Since the measurement error increases as the temperature difference between the inlet and the outlet of the heat exchanger decreases, there are many difficulties in performing the role with reliability as an energy meter.

The existing calorimeter that measures energy shows the calorie value by multiplying the flow rate in the pipe by the state quantity caused by the temperature change in the constant pressure specific heat, but this is limited to the incompressible liquid, and in the case of the actual gas, the physical property value depends on the temperature and pressure. It is difficult to apply the enthalpy value because the temperature difference does not apply, but it is very difficult to apply except general purpose gas.

Therefore, by combining the enthalpy value using the matrix structure and the flow rate measurement method of the gas using the matrix structure to calculate the exact energy to contribute to the energy saving of the industrial site.

In addition, the existing calorimeter is mainly limited to incompressible fluids, but the energy meter applied with this technology calculates enthalpy and converts it into a matrix structure not only for all gases present on earth but also for user-defined mixed gases. An energy measuring device and an energy measuring method for easily calculating energy are provided.

In order to solve the above problems and needs,

A process of inputting the type of gas to be measured, temperature (T), pressure (P), pressure difference (dP), inlet diameter (D) and diameter of throat (d) of the tightening device flow measurement device,

The input constant (the heat insulation index k, the viscosity μ of the gas, the density of the gas ρ Value) a process of selecting and inputting an input constant according to the type, temperature, and pressure of the gas in the database,

A process in which the expansion coefficient? Is calculated using the input adiabatic index k, the diameter ratio? And the pressure ratio?

The process of correcting the runoff coefficient (C),

A gas flow rate measurement process including a process of calculating the expansion coefficient, the corrected outflow coefficient and the pressure difference, the throat diameter, the diameter ratio, and the density of the gas by substituting the gas flow rate formula;

A process in which an enthalpy according to the type, pressure and temperature of the input gas is selected and input from an enthalpy database,

It provides a method for measuring the energy of the gas by calculating the measured gas flow rate and the measured enthalpy.

In addition, the process of correcting the leak coefficient is,

A process in which a specific effluent coefficient is input,

A process in which a gas flow rate is set by an operation process according to a gas flow rate measurement formula,

The process of setting Re as an operation process according to the formula for calculating Re,

The process of correcting the runoff coefficients by calculation according to the runoff coefficient calculation formula,

It provides a method for measuring the energy of the gas, characterized in that the correction process consists of a process of repeating 2 to 10 times.

In addition, the interpolation or extrapolation method is used in the database for input constants (thermal insulation index k, gas viscosity μ, gas density ρ value) according to the type of gas, and the input constant according to the gas type, temperature and pressure is calculated. The input process;

An interpolation or extrapolation method is used in an enthalpy database according to the type of gas, thereby providing a method for measuring energy of a gas, wherein the enthalpy is calculated and input according to the type, temperature, and pressure of the gas.

In addition, a process of measuring and inputting a content ratio of the gas to be measured flow rate mixed in various types,

A process of deriving a single input constant through calculation using the input content ratio and the input constant of the gas to be measured, and

A method for measuring the energy of a gas, comprising calculating a enthalpy of an individual gas of a gas to be mixed with the content ratio of the input gas to derive a single enthalpy of the gas to be mixed. to provide.

The present invention also includes a gas flow measuring body 10 and a pressure sensor 20, a temperature sensor 30, a pressure difference sensor 40 and a display unit 50 mounted on the body,

An information processing apparatus (60) equipped with a program implementing the method of measuring the energy of the gas according to claims 1 to 5, and a predetermined input constant database (70) and an enthalpy database (80) that can be used in the energy measurement program. Provided is provided with an energy measurement device provided.

In addition, there is provided an energy measuring device characterized in that the gas selection unit and / and the function selection unit is further added.

Conventional calorimeters are mainly limited to incompressible fluids, but the energy measuring device using this technology calculates the enthalpy through the thermodynamic method for not only all the gases present on the earth but also the mixed gases defined by the user. The effect is that you can easily calculate the energy by converting it into a database.

In addition, the present invention has the effect that can be applied to any kind of gas, temperature, pressure.

Further, since the input constant (heat insulation index k, viscosity μ of gas, density ρ of gas) of the specific gas is measured and set for a specific gas, it can be used as an input constant by converting it into a database, It is possible to measure the flow rate of the gas quickly and accurately.

In addition, the present invention has an advantage that the present invention can be applied to both cases in which the gas is single, mixed, or mixed and the components are changed.

In addition, the present invention has the effect of providing an energy measuring method that can be applied very well to any type of energy measuring device using a tightening mechanism.

In addition, the energy measuring device according to the present invention has a simple structure and low manufacturing cost, thereby having a high economic effect.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a database (matrix) of the heat insulation index k of methane according to one embodiment of the present invention with respect to temperature and pressure. Fig.
Figure 2 is a database (matrix) of the density p of the gas of methane with temperature and pressure according to one embodiment of the present invention.
Figure 3 is a graph of the viscosity of a gas of methane according to one embodiment of the present invention, temperature and pressure, μ database (matrix).
4 is a flowchart of a gas flow measurement method using a predetermined input constant database according to the present invention.
5 is a flowchart illustrating a process of correcting the flow coefficient C in a gas flow measurement method using a predetermined input constant database according to the present invention.
FIG. 6 is a flowchart illustrating a method of deriving an input constant when a component of a gas mixture changes in a gas flow measurement method using a predetermined input constant database according to the present invention. FIG.
Figure 7 is a three-dimensional perspective view of the energy measuring device of the present invention.
8 is an enthalpy database (matrix) of a gas composed of methane (90%) and nitrogen (10%) according to temperature and pressure according to one embodiment of the present invention.
9 is a flowchart illustrating a process for obtaining an enthalpy of a measuring object consisting of a mixed gas of a single gas and several gases according to the present invention.
10 is a flowchart illustrating a method of measuring energy by measuring flow rate and enthalpy according to the present invention.
11 is a structural diagram of an information processing apparatus according to the present invention;

Hereinafter, the present invention will be described in detail.

The present invention is an energy measuring method for easily performing the correction in measuring the energy of the flow rate for the gas in which the compression occurs by the temperature and pressure as well as the liquid without compression using a commonly used fastener flow meter and Provide an energy measuring device.

That is, the present invention relates to an apparatus and method for measuring a precise energy by applying a flow rate measuring method for accurately measuring the flow rate of a gas to be measured as described below, and also measuring the enthalpy of the gas to be measured.

In the present invention, the tightening device energy measuring device means that a tightening device (called an orifice plate or a nozzle plate) with a small hole is installed in the pipe to tighten the flow, and the flow rate can be measured by using the pressure difference before and after. Means a device or device that measures energy using enthalpy.

In general, the accuracy is high when measuring the flow rate by applying a fastener flow meter to the liquid. However, it is difficult to apply it if the volume changes according to the temperature and the pressure like gas and the compression ratio according to the gas is different.

Conventional gas flowmeters measure the flow rate using a correction factor according to the gas, but the correction coefficient is not only accurate, but also has a disadvantage in that the flow rate for the gas without the correction factor cannot be measured.

In the isentropic system, the flow rate measurement formula of the flow meter using the tightening mechanism is as follows.

(Equation 1)

q _m is the mass flow rate [kg / s], which means the flow rate of the fluid passing through it,

β is the diameter ratio, which means the ratio (diameter ratio) between the inlet diameter and the throat diameter of the tightening mechanism flowmeter.

C means discharge coefficient as discharge coefficient,

ε is the gas expansion coefficient,

d means the diameter of the throat of the tightening device flow meter,

dp is differeitial pressure [Pa], which means the pressure difference between the inlet and the throat of the clamping device flow meter,

ρ is density [kg / m ³ ], which means the density of the specific gas to be measured.

In order to measure the flow rate of the gas in this way, a process of calculating the gas expansion coefficient epsilon, the gas density p _{, and the} correction constant C described above and substituting it into the flow rate measurement formula should be performed.

However, due to the fact that the gas expansion coefficient ε, the gas density ρ _{, and the} discharge coefficient C are determined by the temperature and the pressure of the flowing gas, the temperature and pressure are measured to measure the flow rate of the specific gas, The gas expansion coefficient epsilon, the gas density rho, Computing the runoff coefficient C is complicated and has drawbacks in that it can not be solved without using a large-capacity computer with many memories and central processing units.

In addition, even if a conventional computer is used, there is a problem that it takes a lot of time, and the flow rate of the gas can not be measured immediately.

However, the present invention provides a method for immediately deriving the above-described gas expansion coefficient ε, gas density ρ, and outflow coefficient C even by using an electronic calculation device having a very small capacity, and accordingly, the flow rate can be quickly measured. It provides a method and also provides a method for obtaining energy simply by inputting an enthalpy for it and an energy measuring device.

1. Input constant (insulation index k, gas viscosity μ, gas density ρ)

A technical feature of the present invention is to provide a matrix-type database in which the values for the heat insulation index k, the viscosity μ of the gas, and the density ρ of the gas, which are coefficients necessary for measuring the flow rate of the gas obtained experimentally for a specific gas, And the adiabatic index k for a specific temperature and pressure for the specific gas to be measured, the viscosity μ of the gas, the density ρ of the gas (Computationally) input from this database or by using this database, thereby providing a flow measurement method that does not require complicated computation.

Therefore, the present invention utilizes a matrix structure (database) among the flow measurement methods, and it is applied to the differential pressure type flow meter to measure the flow amount, and it is possible to directly measure the physical measurement values of the tightening mechanism instead of the conventional linear correction flow measurement method. And it is calculated by the mathematical operation that has been input, so it can be said that it is a direct calculation type flow measurement method which does not require linear correction.

In addition, there is no need for complicated calculations, which can significantly reduce computation time, significantly reduce computer capacity, and provide a method for measuring very accurate gas flow.

The present invention relates to a method and apparatus for measuring the heat insulation index k, the viscosity of a gas, and the density ρ of a gas, which have been experimentally determined in advance according to respective temperatures and pressures of a specific gas (or a mixture of two or more kinds of gases) It is used to measure the flow rate, which will be explained next, by building the database in advance.

As described above, the adiabatic index k, the gas viscosity μ, and the gas density ρ can be obtained experimentally of a specific gas (or a mixture of two or more kinds), and the thermal conductivity coefficients already secured by a lot of data for various gases. , Experimental data on the thermal diffusion coefficient, core pressure, etc., and data obtained by thermodynamic equations.

Where k is the isentropic exponent and is called the adiabatic index.

The viscosity μ of the gas, the density ρ of the gas Values correspond to constants that change with specific temperatures and pressures.

Thus, for a given gas, the adiabatic index k, the viscosity μ of the gas, the density of the gas ρ The value of the adiabatic index k, the viscosity μ of the gas, the density of the gas ρ Each database of values is built in advance through experiments.

The prefabricated adiabatic index k, the viscosity μ of the gas, the density of the gas ρ Value is defined as "input constant" in the present invention.

An example of constructing the input constant is shown in Figures 1, 2, and 3 as a database for methane.

Fig. 1 is a table showing values of the heat insulation index k according to respective temperatures and pressures for methane.

Fig. 2 is a table showing viscosity values of gas according to respective temperatures and pressures for methane.

Fig. 3 shows the relationship between the density of gas < RTI ID = 0.0 > p < / RTI > A table showing values.

When the gas to be measured as described above is composed of a single component, or when several gases are mixed at a constant composition ratio, for example, 50% of X gas and 50% of Y gas are constantly introduced into the energy measuring device. If the adiabatic index k for the gas mixed with X and Y, the viscosity μ of the gas, the density of the gas ρ Get the value and make it into a database.

2. Gas flow measurement method using the input constant database

The present invention provides a method for measuring the flow rate of a gas using the above-described database-based input constant.

The present invention performs the process of inputting the type of gas and the inlet diameter (D) and throat diameter (d) of the energy measuring device as shown in FIG.

The inlet diameter D and the neck diameter d are predetermined or can be corrected or set later by the user.

The inlet diameter (D) and the neck diameter (d) are used to obtain the above-mentioned diameter ratio (beta).

Also, such a diameter ratio is used as a value used to obtain a gas expansion coefficient?.

And the input process is performed by performing the process of obtaining the temperature (T), the pressure (P) and the differential pressure (dP) of the measuring object in the tightening mechanism energy measuring device.

The tightening device energy measuring device is equipped with a sensor for measuring the temperature of the flowing gas.

The temperature measuring sensor means an apparatus or a device for measuring a normal temperature.

It also has a sensor to measure the pressure.

The pressure measuring sensor means a device or apparatus for measuring the pressure inside the pipe of the tightening device energy measuring device and the pressure after passing through the throat.

The differential pressure dP means the difference between the pressure inside the pipe of the tightening device energy measuring device and the pressure after passing through the throat.

The differential pressure is simply obtained by the pressure measuring sensor described above.

The pressure measurement sensor and the temperature measurement sensor may be input by digitally transmitting the obtained values for pressure, differential pressure, and temperature.

As described above, the digitalization of the values measured by the sensor can be performed by attaching an ordinary electronic circuit or an MCU or the like with a semiconductor circuit attached thereto.

Therefore, the temperature (T), the pressure (P) and the differential pressure (dP) through the above process is obtained and input as data to be performed in the next process.

(1) In the present invention, the temperature (T) and the pressure (P) obtained through the above process are used for a specific gas or a mixed gas having a constant composition ratio, and the adiabatic index k, the gas viscosity, ρ In the database for values, the adiabatic index k corresponding to a certain temperature and pressure, the viscosity μ of the gas, the density of the gas ρ (The present invention defines such an input process as "the entrance condition composition ratio is fixed type").

In this process, the adiabatic index k corresponding to a specific temperature and pressure of a specific gas (or two or more mixed gases) input, the viscosity μ of the gas, the density ρ of the gas The value is automatically selected.

As described above, in the present invention, the process of selecting a value corresponding to a specific value can be implemented through a general electronic calculator or an arithmetic unit, which typically includes a memory and a central processing unit and is equipped with an application program, to be.

If there is no input constant corresponding to a specific temperature and pressure in the input constant database, the temperature and pressure approaches the specific temperature and pressure, The adiabatic index k, the viscosity of the gas, μ, the density of the gas, ρ And a value can be obtained.

The above interpolation is based on the fact that the shape of the function f (x) of the real variable x is unknown, but the value xi (i) of two or more variables having an interval (irregular interval or irregular interval) = 1, 2, ..., n) is known, it is necessary to estimate a function value for any x between the function values f (xi). It is used when estimating a value from an observed value obtained by an experiment or an observation or obtaining a function value not in the table by a function table such as a log table. The simplest method is to obtain the function value to be obtained by concatenating the points of the variable with the x coordinate and the known function value of the variable with the y coordinate.

Also, by using the expansion of the function, an expression that approximates the function f (x) in the vicinity of the variables x0 and x1,

(x-x0)} / (x1-x0)] (x-x0)

.

This is a simple formula, called a proportional part or linear interpolation. Since x0 and x1 are set to be sufficiently small, as in the logarithmic or trigonometric function table, the linear interpolation is used. Newton's interpolation formula can be used for more rigorous calculations.

The method of finding the approximate value of f (x) for any x outside of x1 and xn in response to the interpolation is called the extrapolation method or the extrapolation method.

Therefore, it goes without saying that the present invention may use extrapolation as well as interpolation.

The method of obtaining an input constant by using the interpolation method or the extrapolation method of the present invention can be implemented by using a computational formula of the interpolation method or the extrapolation method described above.

In the present invention, an example in which the interpolation method is applied using the above input constant database will be described as follows.

1, the value for the adiabatic index k can not be selected when the temperature is 252 (K) and the pressure is 132 (kPa).

Therefore, in this case, an interpolation method usually used as described above can be used.

The temperature 252 (K) is between 250 (K) and 254 (K) and the pressure 132 (kpa) is between the pressure 102 (kpa) and the pressure 152 (kpa) .

As an example, if k1 and k2, which are equivalent to 250 (K), 102 (kpa) and 152 (kpa), are selected, the value of k3 at 132 (kpa) Can be simply calculated.

k3 = k1 + {(k2-k1) / (152-102)} * (132-102)

Similarly, when the adiabatic indexes k4 and k5 corresponding to 254 (k), 102 (kpa) and 152 (kpa) are selected and substituted into the above equation,

k6 = k4 + {(k5-k5) / (152-102)} * (132-102)

And the value of k6 when 132 (kPa) is obtained.

Using the above values of k3 and k6, k7 values at 252 (k) and 132 (kpa) can be obtained, which can be obtained simply by using the above formula.

That is, the value k7 can be obtained from k7 = k3 + {(k6-k3) / (254-250)} * (252-250).

It is possible to easily obtain all the input constants for the temperature (T) and the pressure (P) which are not present in the input constant database by the above interpolation method.

That is, by using the database as shown in Fig. 2 and Fig. 3, the density (p) of the gas and the viscosity (mu) of the gas are also determined by interpolation, which is the same method as described above, And the density (p) of the gas with respect to the pressure and the viscosity (μ) of the gas.

(2) In the present invention, as described above, a process for obtaining an input constant applicable to a case where the ratio of the mixed gas varies with time, unlike the case where a single gas or mixed gas at a fixed ratio is introduced, is performed (In the present invention, this case is defined as the change in the inlet condition composition ratio)

As shown in Fig. 6, when the inlet condition is variable, the adiabatic index k, the viscosity μ of the gas, the density ρ of the gas The value hedging process is performed.

When the inlet condition is varied, the components of the gases G1 and G2 to be measured change with time, so that the user can input when the component content changes with respect to the component content changed with time.

In addition, a device for measuring the content ratio (R) of the component to the gas to be measured may be automatically input by measuring the ratio.

The device for measuring the content ratio of the component means a device or means equipped with a sensor capable of measuring the content of the component of the gas.

The ratio value measured by the content ratio measuring device can be inputted in a manner that is digitized and transmitted. It is a matter of course that a conventional electronic circuit or an MCU with a semiconductor circuit may be attached to the sensor by digitizing the measured value by the sensor.

Thus, the tightening mechanism energy measuring device is provided with a component content sensor to measure the content of the components of the gas and the measured value is input to the following "single input constant derivation calculation process".

The process of deriving a single input constant is as follows.

First, the process of deriving the individual input constants for the gases G1 and G2 whose component contents vary in the same manner as in the derivation of the input constants in the above-described "condition in which the inlet condition composition ratio is fixed" is performed.

Therefore, when the input constant is selected according to the specific temperature and pressure in the input constant database or the input constant is calculated through interpolation as described above, an input constant for G1 and G2 is derived.

The input constants k (adiabatic index k, viscosity μ of the gas, density ρ of the gas) for G1 and G2 thus derived are assumed to be 100% individually.

Therefore, in order to derive a single input constant for such a mixed gas, multiplying the above-described component content ratios yields a single input constant (k, μ, ρ).

That is, in the above example, a corrected single input constant k (k, μ, ρ) * R 1 + G 2 , μ, and ρ) are set. Where R1 is the content ratio to G1 and R2 is the content ratio to G2.

If a single input constant is determined in this way, the next process proceeds as shown below.

In the present invention, a process of obtaining the pressure ratio? Is performed using the above differential pressure data.

The pressure ratio is easily obtained by using the same equation as shown in the following and P (pressure), dP (differential pressure), which are already known data.

The pressure ratio formula is (P-dP / 1000) / p and is obtained by simple calculation.

In the above formula, dP * (1/1000) is for unit conversion (that is, to convert to kPa), so that it can be set differently when other unit Pa is used.

It is needless to say that it is possible to consistently change constants in front of variables for unit conversion in all equations like the pressure ratio formula according to the thermodynamic law.

In the present invention, the process of obtaining the gas expansion coefficient? Is performed using the above-mentioned adiabatic index k, the diameter ratio? And the pressure ratio?.

The above ε (gas expansion coefficient) is a function affected by temperature and pressure, and is obtained by an arithmetic operation using the following formula.

(Formula 2)

τ is the pressure ratio and means the pressure ratio between the inlet and the throat of the tightening device energy measuring device.

and? represents the diameter ratio as described above.

The values of k, τ, and β determined in the above formula are input to obtain the gas expansion coefficient (ε).

Therefore, the gas expansion coefficient? Obtained by the above formula is a gas expansion coefficient for a specific gas at a specific temperature and a specific pressure.

The process of obtaining the outflow coefficient C using the gas expansion coefficient obtained above is performed.

When the outflow coefficient is obtained correctly, the formula for measuring the flow rate of the above-

(Q _m , mass flow rate) is simply measured.

As shown in FIG. 5, the present invention performs a process of obtaining the measured value of the first flow rate by randomly inputting the discharge coefficient C as a specific number.

In the present invention, C may be preferably set between 0.9 and 0.9999, and preferably set to 0.95 to obtain a measurement of the flow rate (in this case, using a tightening mechanism using a nozzle).

Therefore, in the case of the orifice, C about 0.65 and Venturi about 0.93 may be input.

When using a nozzle, the above-mentioned C is input as 0.95, and as before, β, dp, d, ρ If is input, the value of the first flow rate q _m1 is calculated.

In addition, it is preferable that the initial discharge coefficient C is directly inputted with the C value as described above. However, the initial discharge coefficient C may be obtained by calculating the initial Re and performing the calculation by the following equation. In this case, the initial Re typically uses 1000000 and the β value is the input value.

In this way, when the Re value is input, a value close to the above-described outflow coefficient C (= 0.95) is derived, and the following process may be performed in the same manner.

(Equation 4)

Equation (4) is a formula for obtaining the outflow coefficient for the nozzle.

Therefore, when using an orifice, venturi, etc. of the tightening mechanism may be applied to other formulas.

In other words, the general discharge coefficient calculation formula is as follows.

C = a + b (β / Re) ⁿ ------ (Reduced coefficient representative expression)

a, b are constants, n is exponent

It can be expressed as.

As described above, the runoff coefficient correction process used in the present invention can be used to calculate the runoff coefficients according to the respective fasteners by experimentally obtaining a, b, and n in the runoff coefficient representative equation depending on which of the tightening mechanisms is used. to be.

Then, the process of correcting the outflow coefficient C value using the first flow rate value is performed.

The C value is a function of Re (Reynolds number) and when the Re value changes, the C value changes.

Therefore Re is given by the formula

(Equation 3)

The value of Re is obtained when the first flow rate q _m1 obtained above is substituted and the process of inputting the viscosity μ of the gas and the diameter D of the tube is performed.

The process of obtaining the corrected C value [C1] using the obtained Re value is performed.

The corrected C value can be obtained by arithmetic operation using the following formula.

(Equation 4)

If the Re and β values obtained before the above expression are substituted, the corrected C value is obtained.

Of course, as mentioned above, the C value in the case of using an orifice or a venturi in addition to the nozzle is obtained by a calculation operation using the above-described leakage coefficient representative formula.

Equation (1) above is used to calculate the corrected C value [C1] obtained above.

Substituting the formula, the process of calculating the value of the second flow rate q _m2 is performed.

When the second flow rate value is calculated, the corrected Re value is obtained by using the second flow rate value (q _m2 ).

Then, again, the C value can be obtained by using the Re value derived above.

The process of correcting the runoff coefficient C value as described above is performed 2 to 10 times.

Preferably 3 to 5 times.

Through the above iterative process, it is possible to accurately derive the runoff coefficient C value.

In this way, it is possible to accurately measure the flow rate of any specific gas when the outflow coefficient C is corrected and derived.

Therefore, as described above, the outflow coefficient C derived from the correction process for accurately calculating the outflow coefficient C and the input constants (density ρ) of ε, d, dp, And performs the input process.

(Equation 1)

Through this process, an accurate mass flow rate ( q _m ) of the flowing gas can be obtained.

And again, the process of obtaining the volumetric flow rate through this mass flow rate can be performed.

The formula for calculating the volumetric flow rate (q _v ) is as follows.

(q _v ) = q _m / ρ [m ³ / s]

In addition, a process of obtaining a flow rate of the fluid through the volume flow rate may be performed.

The velocity formula (V) is as follows.

[m/s]

[m / s]

Also, the process of obtaining the sound velocity using the above-described pressure P, gas density p, and adiabatic index k may be performed.

The formula for calculating sound velocity (a) is as follows.

[m/s]

[m / s]

The formula for calculating Mach number is as follows.

M = V / a [M]

The above formulas are simple formulas and can be implemented through simple programs or operators.

Therefore, in the present invention, the process of deriving a certain value by using the formula (or formula) used in the present invention consistently uses an application program programmed for the formula as mentioned above, or through a common calculator. Will be performed.

Then, a process of displaying the mass flow rate, the volume flow rate, the flow rate, the sound velocity and / or the Mach number is performed.

Thus, the present invention provides a method for accurately measuring the flow rate of the gas required by the energy measuring device through the above process.

3. enthalpy  How to build a database and measure energy

The present invention measures the flow rate of the gas to be measured (regardless of mass flow rate or volume flow rate) and measures the enthalpy at a specific temperature and pressure of the gas to be measured and multiplies the measured flow rate and enthalpy to be measured. The energy of the gas can be obtained.

In other words, the energy formula is P = q _m × H.

Where P is energy (kJ / s)

q _m is the mass flow rate described above (kg / s)

H is enthalpy (kJ / kg).

Therefore, the unit of P is kJ / s.

(If the volume flow rate is not mass flow rate, the unit of enthalpy is (kJ / l), etc.)

Therefore, the present invention performs a process of obtaining the enthalpy (H) according to the temperature and pressure of the specific gas to be measured in advance to database.

As such, the enthalpy according to the temperature and pressure of the gas may be databased in a matrix form using previously measured values or existing thermodynamic data for various kinds of gases.

Thus, a database can be constructed in a matrix format for enthalpy for a single gas over temperature and pressure.

In this case, as in the method of measuring the flow rate described above, it means a specific gas or a mixed gas having a constant composition ratio (a type having a fixed inlet composition ratio).

Therefore, as shown in FIG. 8, a database may be constructed in a matrix format for temperature and pressure of the mixed gas.

The enthalpy data metric of FIG. 8 shows an enthalpy database according to the temperature and pressure of a gas composed of methane (90%) and nitrogen (10%).

As such, the present invention enables the construction of an enthalpy database according to temperature and pressure for a pure single gas (methane, ethane, propane, nitrogen, etc.) as shown in FIG.

The process of databaseing the enthalpy for the various gases configured as described above is performed.

In the present invention, when there is no enthalpy for a particular temperature and pressure of a gas to be measured in the enthalpy database of the matrix structure, as described above in the input constant, the present invention finds a temperature and pressure close to the specific temperature and pressure. The process of obtaining the enthalpy corresponding to the specific temperature and pressure may be performed by using interpolation or extrapolation.

For example, to find the energy for a single gas, the enthalpy for a particular temperature and pressure can be found by searching the enthalpy database for a single gas. That is, it is implemented in the same manner as searching and inputting the input constant described above.

In addition, as shown in the example of FIG. 8, when an enthalpy database is constructed as a single gas as shown in the example of FIG. 8, the enthalpy for a single gas can be obtained by searching the enthalpy.

In addition, it is possible to recognize the mixed gas as a single gas as described above, if it is input to be recognized as a single gas in the process of inputting the measuring object as described above.

Of course, in the present invention, the process of selecting an enthalpy corresponding to a specific value (temperature, pressure) typically includes a memory and a central processing unit, and accordingly, may be implemented through a general electronic calculator or a calculator equipped with an application program. Of course it can.

As described above, when the type, pressure, and temperature of the gas to be measured are input, the process of searching for an enthalpy according to the enthalpy database is performed.

In addition, in the present invention, when the gas to be measured is composed of a mixed gas, it is not recognized as a single gas, and when it is recognized as a mixed gas, it is possible to obtain a single enthalpy by using the content of individual gases included in the mixed gas. .

For example, a method for obtaining a single enthalpy of a gas G consisting of A (methane 90%. G1) and B (10% ethane, G2) can be obtained using the enthalpy database for a single gas as described above. do.

That is, it can be found by finding the enthalpy (Ha) in the enthalpy database for A for a specific temperature and pressure, and also the enthalpy (Hb) in the enthalpy database for B.

Knowing the content ratio (mixing ratio) of gas A and gas B to Ha and Hb thus obtained, it is possible to obtain a single enthalpy (Ht) of the mixed gas.

That is, in the above example, it is obtained through the calculation of Ht = Ha * 0.9 + Hb * 0.1.

Such a single enthalpy calculation process can be simply performed in the central processing unit of the present invention.

The mixing ratio of the measurement target gas, which is the mixed gas, can be easily obtained through the content ratio as mentioned above.

That is, in the example presented in the above-described flow measurement method, R1 and R2 become a mixing ratio.

The mixing ratio is, of course, automatically inputted in the process of inputting the ratio of the mixed gas which is the measuring counterpart. That is, as will be described later, the mixing ratio of the mixed gas is inputted in the gas selecting portion of the mixed gas.

In addition, such a mixing ratio calculation process can be easily performed in the central processing unit of the present invention.

In addition, the present invention can be applied to a case where the ratio of the mixed gas changes with time as described in the above-described flow measurement method.

If the inlet conditions are varied, the components of the gas (G1, G2) to be measured change with time, and the ratio is measured by a device for measuring the content ratio (R) of the component to the gas to be measured.

The device for measuring the content ratio of the component means a device or means equipped with a sensor capable of measuring the content of the component of the gas.

As mentioned above, the ratio value measured by the content ratio measuring device may be input in a digitized manner. It is a matter of course that a conventional electronic circuit or an MCU with a semiconductor circuit may be attached to the sensor by digitizing the measured value by the sensor.

As such, the energy measuring device includes a component content sensor to measure the content of the gas component, and the content ratio of the measured component is input to the "single enthalpy calculation process" as described above.

FIG. 9 is a flowchart illustrating a method for obtaining an enthalpy of a measuring object consisting of a single gas (including a case where a mixed gas is recognized as a single gas) and a mixed gas mixed with several gases according to the present invention.

As described above, the operation of the formula may include a memory and a central processing unit, and accordingly, may be implemented through a general electronic calculator or an operator equipped with an application program.

As described above, the present invention can calculate energy by multiplying the wander and enthalpy measured above.

That is, the energy of the gas to be measured is measured by inputting and calculating q _m and H calculated from the energy formula P = q _m × H.

FIG. 10 shows a flowchart of a method for obtaining energy using the gas flow rate measuring method and the enthalpy measuring method as described above.

Of course, the calculation for such a formula can be implemented through a conventional electronic calculator or a calculator, which typically includes a memory and a central processing unit, and thus an application program, as described above.

And a process of displaying the energy in the display unit for displaying the energy is performed.

As described above, the gas flow rate measuring method, the enthalpy measuring method, and the energy measuring method according to the description of the present invention are program instructions for performing operations implemented in a computer, a calculator, a calculator, an information processing apparatus, or the like, as described above. Computer-readable media, including.

The computer readable medium may include program instructions, data files, data structures, etc. alone or in combination. The medium is a program instruction

May be those specially designed and constructed for the present invention, or they may be of the kind well-known and available to those having skill in the computer software arts.

Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tape, optical media such as CD-ROMs, DVDs, and magnetic disks, such as floppy disks. Magneto-optical media, and hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like.

Examples of program instructions include machine language code such as those produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter or the like.

Therefore, the gas flow rate measuring method, the enthalpy measuring method and the energy measuring method according to the present invention are performed in the above-described central processing unit.

4. Application

In addition, the present invention can use the gas flow rate measurement method using the above 2. input constant database as mentioned above, and can also implement 3. enthalpy database construction and energy measurement process as an application program.

As described above, the above process is a calculation process and an algorithm for an equation such as a flow measurement formula for gas, an input constant selection or / and calculation process, and an outflow coefficient correction process.

In addition, calculation procedures and algorithms for equations, such as a process of obtaining energy by using the measured flow rate measurement value and the measured enthalpy value for any specific gas, are presented.

Therefore, the above process can be programmed as an application program using a normal C language, Java, Fortran, or the like.

FIG. 4 is a flow chart showing a method of measuring the gas flow rate in a fixed form of the inlet condition composition ratio, and an application program implementing the algorithm for such a method may be produced.

FIG. 5 is a flowchart illustrating a method of accurately correcting the outflow coefficient of FIG. 4, and FIG. 4 shows an application program implementing an algorithm for the correction method of FIG. An application program for measuring the gas flow rate can be produced.

In addition, FIG. 6 shows a flowchart of a method for correcting an input constant in a form in which an entrance condition composition ratio is variable. When an application program implementing an algorithm for such a method is added to the above application program, the entrance condition composition ratio is variable. Applications can be written to measure the gas flow rate in the pre-configured form.

9 shows a flowchart of a method for inputting an enthalpy in a form in which the entrance condition composition ratio is constant or variable. When an application program implementing the algorithm for such a method is added to the above application program, the entrance condition composition ratio is increased. You can write applications that measure enthalpy in constant or variable forms.

10 is a flowchart illustrating a method of measuring energy of a gas according to the present invention. When an application program for implementing an algorithm for the method is added to the above application program, an application program for measuring energy of a gas in a form is shown. I can make it.

Such an application program corresponds to a very simple application program and is not only large in capacity but can be easily mounted on an information processing apparatus having a memory and a central processing unit (CPU) or an MCU (Micro Controller Unit).

Accordingly, the present invention provides an energy measurement program that specifically implements the above-described method of measuring energy of a gas using a programming language.

5. Energy measuring apparatus using the method of measuring the energy of the gas of the present invention

The present invention provides a tightening device energy measuring device or energy measuring system using the above-described energy measuring method of the gas (hereinafter referred to as "energy measuring device").

Energy measuring device of the present invention is provided with an energy measuring body 10 and the pressure sensor 20, the temperature sensor 30, the pressure difference sensor 40, the display unit 50 is mounted on the body, An information processing apparatus 60 equipped with an application program that specifically implements an energy measuring method is provided and includes an input constant database 70 and an enthalpy database 80 that can be used in the application program.

Figure 7 shows a three-dimensional perspective view of the energy measuring device of the present invention.

The energy measuring device body of the present invention means a portion through which gas passes, and means a tubular device or device equipped with a tightening mechanism (1, nozzle, etc.).

The pressure sensor 20 is mounted on the inlet and tightening device mounting portion of the body to obtain the pressure of the inlet and tightening device mounting portion of the body described above.

Therefore, since the pressure difference dP can be obtained through the pressure sensor, the pressure difference sensor 40 is a concept including a device or a device that works in conjunction with the pressure sensor.

The body is also provided with a temperature sensor 30 for sensing the temperature of the gas.

The present invention is provided with a transmission means for transmitting the sensed measured value in the pressure sensor, temperature sensor, pressure difference sensor.

In addition, the transmission means may include a digital signal converter for converting the measured value of the sensor into a digital signal when the analog signal is input.

In the present invention, the information processing device 60 is a device or device equipped with a memory unit and a CPU, MCU, etc., which is equipped with an application program that implements the energy measuring method of the present invention as a computer program and can drive the same. it means.

The information processing apparatus of the present invention may include a gas selection unit 61 for selecting a type of gas to be measured.

The user selects and inputs a kind of gas or a mixed gas by the gas selecting unit.

In addition, in the case of the gas mixed in the gas selection unit, since the type and mixing ratio of the gas are input, the component content ratio is automatically input to the information processing apparatus.

The gas selection unit may further include a function selection unit 62 for selecting a configuration in which an inlet condition composition ratio is fixed or a configuration in which an inlet condition composition ratio is variable.

The function selection unit allows the information processing apparatus to select an application program according to a fixed form of the entry condition composition ratio or a variable form of the entry condition composition ratio.

As mentioned above, the present invention may be provided with a gas component content rate measuring apparatus 63 added thereto.

Device for measuring the content ratio of the components means a device or means equipped with a sensor that can measure the content of the components of the gas.

The sensor of the component content ratio measuring apparatus means a conventional apparatus or means capable of measuring the component of a gas using ultrasonic waves, light waves, and the like.

For example, it refers to an apparatus using a gas sensor for detecting the mixed gas of Patent No. 10-1014851 (Method for manufacturing gas sensor for detecting the mixed gas and gas sensor).

The content ratio measuring device automatically measures the content ratio in case of mixed gas when the inlet condition is varied, but the same kind of gas, but the content ratio is changed and the content ratio is automatically measured in the information processing device. Will be entered.

The content rate value measured by the content rate measuring device may be input in a digitized manner. It is a matter of course that a conventional electronic circuit or an MCU with a semiconductor circuit may be attached to the sensor by digitizing the measured value by the sensor.

In addition, the information processing apparatus is provided with a receiving means for receiving the pressure, temperature, pressure difference values detected by the pressure sensor 20, the temperature sensor 30, the pressure difference sensor 40.

As such, the measured value is received as a digital signal and the received value is input to the application program.

In this way, an input constant for the type, pressure, temperature, and pressure difference value of the input gas may be selected by the application program from the input constant database or the flow rate of the gas may be accurately measured through a calculation process.

In addition, the enthalpy of the gas, the pressure, and the temperature of the input gas may be accurately measured by the application program in the enthalpy database or through a calculation process.

The energy of the gas is measured by multiplying the measured gas flow rate by the measured enthalpy.

In the present invention, the information processing apparatus, the input constant database and the enthalpy database may be mounted on a display unit to be described below or provided outside the body of the energy measuring apparatus.

The display unit 50 of the present invention performs a function of indicating the flow rate or / and energy of the gas accurately measured.

The present invention makes it possible to easily select or calculate the input constant according to a specific gas, a specific temperature, and a specific pressure by making a database of input constants which are indispensable for measuring the energy of a gas, which is the technical idea of the present invention. In addition, the enthalpy database according to the enthalpy is to easily select or calculate the enthalpy according to a specific gas, a specific temperature, a specific pressure and provide an energy measuring device that can obtain accurate energy using this.

The present invention is very useful in the industry of producing, selling, and providing a device for measuring the flow rate or energy of a gas.

The present invention is also a very useful invention for the industry of measuring the flow rate or energy of a gas.

The present invention is also applicable to industries that produce, sell, and provide gas.

1: Fastening Mechanism
10: energy measuring device body 20: pressure sensor
30: temperature sensor 40: pressure difference sensor
50: Display unit 60: Information processing device equipped with a gas flow rate measurement program
61: gas selector 62: function selector
63: gas component content ratio measuring device
70: input constant database
80: Enthalpy Database

Claims (7)

Input constants according to the type of gas, pressure and temperature (thermal index k, gas viscosity μ, gas density ρ The process of building a database of matrix structures,
Process in which the enthalpy according to the gas type, pressure and temperature is built into the enthalpy database of the matrix structure,
The process of inputting the type of gas to be measured, temperature (T), pressure (P), pressure difference (dP), inlet diameter (D) and throat diameter (d) of the tightening device energy measuring device,
The input constant according to the type, temperature, and pressure of the gas is selected from the database of a matrix structure for the input constant (thermal insulation index k, gas viscosity μ, gas density ρ value) according to the type of the gas inputted. Process,
A process in which the expansion coefficient? Is calculated using the input adiabatic index k, the diameter ratio? And the pressure ratio?
The process of correcting the runoff coefficient (C),
A gas flow rate measurement process including a process of calculating the expansion coefficient, the corrected outflow coefficient and the pressure difference, the throat diameter, the diameter ratio, and the density of the gas by substituting the gas flow rate formula;
A process in which an enthalpy according to the type, pressure and temperature of the input gas is selected and input from an enthalpy database having a matrix structure,
And measuring the energy of the gas by calculating the measured gas flow rate and the measured enthalpy.
The method of claim 1,
The process of correcting the runoff coefficient is
The process of entering a specific runoff coefficient,
A process in which a gas flow rate is set by an operation process according to a gas flow rate measurement formula,
The process of setting Re as an operation process according to the formula for calculating Re,
The process of correcting the runoff coefficients by calculation according to the runoff coefficient calculation formula,
Method for measuring the energy of the gas, characterized in that consisting of a process of repeating the correction process 2 to 10 times.
3. The method according to claim 1 or 2,
The input constant according to the type, temperature and pressure of the gas is calculated by using the interpolation or extrapolation method in the database according to the preset gas type (thermal insulation index k, gas viscosity μ, gas density ρ value). Input process, and
Method for measuring the energy of the gas characterized in that the enthalpy according to the type, temperature, pressure of the gas is calculated and input by using the interpolation or extrapolation method in the enthalpy database according to the type of the gas.
3. The method according to claim 1 or 2,
Including a process of measuring and inputting the content ratio of the gas to be measured flow rate mixed in various types,
A process of deriving a single input constant through calculation using the input content ratio and the input constant of the gas to be measured, and
And calculating the enthalpy of the individual gas of the gas to be mixed with the content ratio of the input gas, thereby obtaining a single enthalpy of the gas to be mixed.
The method of claim 3,
Including a process of measuring and inputting the content ratio of the gas to be measured flow rate mixed in various types,
A process of deriving a single input constant through calculation using the input content ratio and the input constant of the gas to be measured and
And calculating the enthalpy of the individual gas of the gas to be mixed with the content ratio of the input gas, thereby obtaining a single enthalpy of the gas to be mixed.
A gas flow rate measurement body 10 and a pressure sensor 20, a temperature sensor 30, a pressure difference sensor 40 and a display unit 50 mounted on the body,
An information processing device (60) equipped with a program implementing the method of measuring the energy of the gas of any one of claims 1 or 2, a predetermined input constant database (70) that can be used in the energy measurement program, and An enthalpy database (80) is included and provided with the energy measurement device.
The method according to claim 6,
Energy measuring device characterized in that the gas selection unit and / and the function selection unit is added.

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