KR20140136308A - a volume perceiving ilquid flow meter program and the ilquid flow rate measuring method - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a volumetric liquid flowmeter program and a liquid flowmeter, and more particularly, to a liquid flowmeter using a tightening mechanism (nozzle, orifice, venturi, etc.) And more particularly, to a liquid flow meter program and a liquid wander measurement method capable of accurately measuring the liquid flow rate even when the volume of the fluid is changed.
The present invention is characterized in that the kind of the liquid to be measured, the temperature (T), the pressure (P), the pressure difference (dP), the inlet diameter (D) of the tightening device flowmeter and the diameter process,
The input constant (the viscosity of the liquid, μ, the density of the liquid ρ A step of selecting and inputting an input constant according to the kind, temperature, and pressure of the liquid in the database,
A process in which the outflow coefficient C is corrected,
And calculating the calculated expansion coefficient, corrected outflow coefficient and pressure difference, throat diameter, diameter ratio, and density of the liquid by substituting the measured values into a liquid flow rate measurement formula.
In addition, the process in which the effluent coefficient is corrected,
A process in which a specific effluent coefficient is input,
A process in which a liquid flow rate is set by an operation process according to a liquid flow rate measurement formula,
Re is the process of setting Re as an operation process according to the formula,
A process in which the outflow coefficient is corrected by calculation according to the outflow coefficient calculation formula,
And the calibration process is repeated 2 to 10 times.
In addition, the process includes the process of inputting and measuring the content ratio of the liquid to be mixed,
And a single input constant is derived through an operation using the input content ratio and the input constant of the liquid to be measured.
The present invention also provides a liquid flow measurement program implemented using a programming language.
A liquid flow measuring body 10 and a pressure sensor 20, a temperature sensor 30, a pressure difference sensor 40 and a display unit 50 are mounted on the body,
There is provided a liquid flow rate measuring apparatus including an information processing apparatus (60) equipped with the liquid flow rate measuring program of claim 6 and a preset input constant database (70) usable in the above liquid flow rate measuring program.

Description

A volumetric liquid flow meter program and a liquid flow rate measuring method are disclosed.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a volumetric liquid flowmeter program and a liquid flowmeter, and more particularly, to a liquid flowmeter using a tightening mechanism (nozzle, orifice, venturi, etc.) And more particularly, to a liquid flow meter program and a liquid wander measurement method capable of accurately measuring the liquid flow rate even when the volume of the fluid is changed.

와 같이 나타낼 수 있다. 여기서 ρ₁은 유체의 밀도(kg/m³)이다. 기존의 액체유량계는 유체의 비압축성 특성에 따라 밀도는 일정하다고 가정하고, 조임기구의 차압(Δp)만을 측정하여 체적유량을 표시한다. The flow equation for the incompressible fluid using a throttling mechanism (nozzle, orifice, venturi, etc.) is given by the Bernoulli equation

As shown in Fig. Where ρ ₁ is the density of the fluid (kg / m ³ ). A conventional liquid flowmeter assumes that the density is constant depending on the incompressible nature of the fluid, and measures the volume flow rate by measuring only the differential pressure (Δp) of the tightening mechanism.

The density of an incompressible fluid changes slightly at a certain temperature and under a pressure condition, but at a constant temperature and pressure condition (eg, high temperature and high pressure conditions), the density is not constant. In other words, since the change in density means a change in specific volume, a conventional volumetric flow meter that measures the flow rate by only measuring the pressure difference without calculating the density of the liquid causes an error and its use range becomes very narrow.

Also, in the case of a conventional volumetric flow meter that performs temperature compensation, since the volume is decreased when the pressure is increased, there is a restriction on the use and the volume error can not be compensated. In the case of linear flowmeters (Coriolis, Ultrasonic, Vortex type, etc.) using correction coefficients, the flow rate is expressed by a linear function of the flow rate. If the linearity of the linear flowmeter is not compensated, the error is caused.

In the case of liquid piping, pressurized flow is carried out in order to send out at high pressure or to increase the effect of transferring fluid energy at high temperature. In this case, the liquid density is not constant but varies because it is sent out as supercooled liquid rather than saturated liquid. . In the case of conventional flow meters, where the fluid pressure and temperature change are present, the measurement error will always be present unless there is density compensation.

In the case of mixed liquids, if the mixing ratio is changed, the mass flow measurement is not possible and depends only on the volumetric flow rate, which can result in significant cost loss due to the inherent flow error.

In contrast to the above conventional incompressible fluid flow measuring apparatus or method, only a fluid having a constant density can be measured. However, the present invention is applicable to a fluid flow measuring apparatus capable of measuring a flow rate at which a volume varies with a change in density according to a wide range of temperature and pressure Measuring program or apparatus or method.

The present invention also provides a flow measurement program or apparatus or method capable of accurately measuring the flow rate even when the pressure on the liquid exceeds the critical pressure.

Also, the present invention provides a flow rate measuring program, apparatus, or method that solves the problem that volume is reduced when a pressure is increased even in the case of an existing volumetric flow meter that performs temperature compensation, I want to.

Further, the present invention has a problem that the density is not constant when the pressurized flow is carried out in order to increase the effect of transferring fluid energy at a high temperature in a conventional volumetric flowmeter, or a flow measurement program or apparatus or method .

The present invention is also applicable to a conventional volumetric flowmeter in which, in the case of a mixed liquid, mass flow rate measurement is not possible when the mixing ratio is changed, and only depends on the volumetric flow rate, which causes massive cost loss due to the inherent flow error, Method.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems,

The process of inputting the type of liquid to be measured, the temperature (T), the pressure (P), the pressure difference (dP), the inlet diameter (D) and the diameter (d)

The input constant (the viscosity of the liquid, μ, the density of the liquid ρ A step of selecting and inputting an input constant according to the kind, temperature, and pressure of the liquid in the database,

A process in which the outflow coefficient C is corrected,

And calculating the calculated expansion coefficient, corrected outflow coefficient and pressure difference, throat diameter, diameter ratio, and density of the liquid by substituting the measured values into a liquid flow rate measurement formula.

The process of inputting the type of liquid to be measured, the temperature (T), the pressure difference (dP), the inlet diameter (D) and the diameter of the throat (d)

The process of calculating and inputting the pressure P by the input temperature T,

The input constant (the viscosity of the liquid, μ, the density of the liquid ρ A step of selecting and inputting an input constant according to the kind, temperature, and pressure of the liquid in the database,

A process in which the outflow coefficient C is corrected,

And calculating the calculated expansion coefficient, corrected outflow coefficient and pressure difference, throat diameter, diameter ratio, and density of the liquid by substituting the measured values into a liquid flow rate measurement formula.

In addition, the process in which the effluent coefficient is corrected,

A process in which a specific effluent coefficient is input,

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

Re is the process of setting Re as an operation process according to the formula,

A process in which the outflow coefficient is corrected by calculation according to the outflow coefficient calculation formula,

And the calibration process is repeated 2 to 10 times.

In addition, the process includes the process of inputting and measuring the content ratio of the liquid to be mixed,

And a single input constant is derived through an operation using the input content ratio and the input constant of the liquid to be measured.

The present invention also provides a liquid flow measurement program implemented using a programming language.

A liquid flow measuring body 10 and a pressure sensor 20, a temperature sensor 30, a pressure difference sensor 40 and a display unit 50 are mounted on the body,

There is provided a liquid flow rate measuring apparatus including an information processing apparatus (60) equipped with the liquid flow rate measuring program of claim 6 and a preset input constant database (70) usable in the above liquid flow rate measuring program.

The present invention has the effect of measuring the flow rate of the liquid whose volume changes according to the change of the density depending on the temperature and the pressure.

Particularly, the present invention exhibits an effect and an effect of accurately measuring the flow rate even when the pressure on the liquid exceeds the critical pressure and the density is greatly changed.

Also, in the conventional volumetric flow meter which performs conventional temperature compensation, since the volume is decreased when the pressure is increased, there is a restriction on the use and a problem that the volume error can not be compensated can be solved.

In addition, when pressurized flow is performed to increase the effect of transferring fluid energy at a high temperature in a conventional volumetric flowmeter at a high pressure or in a high temperature state, there is a problem that the density is not constant, and the present invention creates the effect of solving this problem.

The present invention can be applied to any kind of liquid, temperature, and pressure.

Further, the present invention can be used as an input constant by computing a set value of an input constant (viscosity μ of a liquid, density ρ of a liquid) that has been measured and set for a specific liquid, computing device can be used to measure the liquid flow rate quickly and accurately.

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

Further, the liquid flow rate measuring apparatus according to the present invention has a simple structure and a low manufacturing cost, and thus has a high economic effect.

FIG. 1A is a graph of density change with water temperature. FIG.
1B is a graph showing changes in liquid density with respect to pressure and temperature of water
2 is a database (matrix) of density r of a particular liquid (R134a (refrigerant)) according to one embodiment of the present invention with temperature and pressure.
Figure 3 is a viscosity μ database (matrix) of a particular liquid R134a (refrigerant) according to one embodiment of the present invention with temperature and pressure).
4 is a flow diagram of a method for measuring liquid flow using a preset input constant database according to the present invention.
FIG. 5 is a flow chart illustrating a process of correcting the flow coefficient C in a liquid flow measurement method using a predetermined input constant database according to the present invention. FIG.
6 is a process flow diagram for deriving an input constant when a component of a mixed liquid changes in a liquid flow measurement method using a predetermined input constant database according to the present invention.
7 is a structural view of a liquid flow rate measuring apparatus using the liquid flow rate measuring method according to the present invention.

Hereinafter, the present invention will be described in detail.

The present invention relates to a flow rate measuring program for facilitating the correction of a flow rate for a liquid in which compression is caused by temperature and pressure as well as a liquid without compression in a generally used tightening device volumetric flowmeter and a flow rate measurement method using the same And a flow rate measuring apparatus therefor.

In the present invention, the term "tightening device flow meter" means an apparatus or a device which is provided with a small-sized fastening mechanism (referred to as an orifice plate or nozzle plate) in a pipe to tighten the flow and measure the flow rate at the pressure difference therebetween.

As described above, in general, when the temperature and the pressure are constant, accuracy is high when the flow rate is measured by applying a tightening device flowmeter to the liquid. However, when the volume varies depending on the temperature and the pressure, and the compression ratio varies depending on the liquid, errors are generated.

Conventional liquid flowmeters measure the flow rate by using a correction coefficient according to the liquid, but the correction coefficient is not accurate as well as there is a disadvantage that the flow rate for the liquid without the correction coefficient can not be measured As you can see.

As shown in FIG. 1A, when water is measured by a volumetric flow meter, the density at 15 degrees Celsius and 85 degrees Celsius is about 1.52 percent.

Even in the case of the liquid, the density changes depending on the temperature, so that the accurate flow rate can not be measured.

Since liquids are incompressible, the effect of density and viscosity is dominated by temperature (T).

In the case of pressure, there is little effect on the density and viscosity coefficient changes, but when the pressure is increased near the critical pressure, the deviation increases and the error is less than 1%.

The pressure (p) = aT ³ + bT ² + cT + d is summarized in the general pressure (20 bar for R134a (refrigerant)).

Therefore, when the flow rate is less than 50% of the critical pressure, it is possible to utilize the calculated density and viscosity coefficient by calculating the pressure by simple temperature measurement.

That is, when the pressure of the user is less than 50% of the critical pressure, the pressure sensor can be removed and the flow rate can be measured only by the temperature.

However, at more than 50% of the critical pressure, both the temperature and the pressure should be measured and the density and the viscosity coefficient matrix should be used to obtain a more accurate value.

FIG. 1B is a graph showing the change in liquid density with respect to the pressure and temperature of liquid water.

As described above, the present invention provides a flow measurement program that can accurately measure even above a critical pressure for the liquid, a flow measurement method using the same, and a flow measurement device thereof.

In the present invention, the flow rate measurement formula of the volumetric flow meter using the tightening mechanism is as follows.

(Equation 1)

q _m is the mass flow rate [kg / s]

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

C is the discharge coefficient as a discharge coefficient,

d is the diameter of the throat of the flowmeter,

dp is the differeitial pressure [Pa] (differential pressure), which means the pressure difference between the inlet and the throat of the tightening device flowmeter,

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

In order to measure the flow rate of the liquid in this way, the procedure of calculating the above-mentioned liquid density ρ _{and the} correction constant C by substituting the above equation into the flow rate measurement formula should be performed.

However, due to the fact that the liquid density p _{and the} discharge coefficient C are determined by the temperature and the pressure of the liquid, the temperature and pressure are measured to measure the flow rate of the specific liquid, and the liquid density p , Computing the runoff coefficient C is not only complicated, but also 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 liquid can not be measured immediately.

However, the present invention provides a method capable of immediately deriving the liquid density p and the outflow coefficient C by using an electronic calculator having a very small capacity, and provides a method for quickly measuring the flow rate.

1. Input constant (viscosity of liquid, μ of liquid) ρ

The technical feature of the present invention is to construct a database in the form of a matrix in which the viscosity μ of the liquid and the density ρ of the liquid, which are coefficients necessary for measuring the flow rate of the liquid experimentally obtained by the user in advance, The viscosity μ of the liquid versus the specific temperature and pressure for the particular liquid you want to measure, the density of the liquid ρ And the flow rate measurement method can be easily selected from the database or input (or computed) by using the database.

Therefore, the present invention uses 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 a flow measurement method of a conventional linear flow meter (Coriolis type, ultrasonic type, This is a direct calculation type flow measurement method that does not require linear correction because the physical measurement value of the non-tightening mechanism is directly detected and calculated by the mathematical operation inputted.

In addition, since there is no need for complicated calculations, the computation time can be remarkably reduced, the capacity of the computer can be significantly reduced, and a method of measuring a highly accurate liquid flow rate can be provided.

The present invention is characterized in that a matrix-type database in which the viscosity μ of the liquid and the density ρ of the liquid, which are obtained experimentally in advance according to respective temperatures and pressures, are summarized for a specific liquid (or a mixture of two or more kinds) And used to measure the flow rate to be described next.

As described above, the viscosity μ of the liquid and the density ρ of the liquid can be obtained experimentally for a specific liquid (or two or more kinds of liquids) experimentally, and the thermal conductivity coefficient, the thermal diffusion coefficient, Core pressure, etc., and data obtained by thermodynamic equations.

The viscosity μ of the liquid, the density ρ of the liquid The value corresponds to a constant that varies with a specific temperature and pressure.

Thus, for a particular liquid, the viscosity μ of such a liquid, the density of the liquid ρ The value of the viscosity of the liquid μ, the density of the liquid ρ Concentrate each database for a value.

The viscosity μ of the pre-built liquid, the density of the liquid ρ Value is defined as "input constant" in the present invention.

An example of building an input constant is shown in Figures 2 and 3 for a database of water.

Fig. 2 is a table showing viscosity values of liquid according to respective temperatures and pressures against water.

Fig. 3 shows the relationship between the density of liquid < RTI ID = 0.0 > It is a table showing the value.

In the case where the liquid to be measured is composed of a single component or a plurality of liquids are mixed at a constant composition ratio, for example, 50% of the X liquid and 50% of the Y liquid, The viscosity μ of the liquid with respect to the liquid mixed with X and Y, the density ρ of the liquid And the database is converted into a database.

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 liquid according to respective temperatures and pressures for methane.

Figure 3 shows the relationship between the density of liquid < RTI ID = 0.0 > It is a table showing the value.

In the case where the liquid to be measured is composed of a single component or a plurality of liquids are mixed at a constant composition ratio, for example, 50% of the X liquid and 50% of the Y liquid, , The adiabatic index k for the liquid mixed with X and Y, the viscosity μ of the liquid, the density ρ of the liquid And the database is converted into a database.

2. Method for measuring liquid flow rate using the input constant database

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

As shown in FIG. 4, the present invention performs a process of inputting the type of liquid and inputting the inlet diameter D and the throat diameter d of the tightening device liquid flow rate measuring apparatus.

The inlet diameter (D) and the neck diameter (d) are preset or can be calibrated 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).

Then, the process of inputting the temperature (T), the pressure (P) and the differential pressure (dP) of the liquid to be measured is performed in the liquid flow rate measuring apparatus of the tightening device.

Fasteners The liquid flowmeter is equipped with a sensor to measure the temperature of the liquid being flowed.

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

Further, the present invention is equipped with a sensor for measuring the above-mentioned pressure.

The pressure measuring sensor means a device or a device for measuring the pressure in the pipe of the tightening device liquid flowmeter and the pressure after passing through the throat.

The differential pressure (dP) means the difference between the pressure in the pipe and the pressure after passing through the throat of the above-mentioned tightening device liquid flowmeter.

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

The pressure measuring sensor and the temperature measuring sensor may be inputted with a method of digitizing and transmitting the values of pressure, differential pressure, and temperature obtained.

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 pressure difference (dP) are obtained through the above process 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 liquid or a mixed liquid having a constant composition ratio, and the viscosity μ of the liquid, The viscosity of the liquid corresponding to a certain temperature and pressure in the database for the value μ, the density of the liquid ρ (In the present invention, this input process is defined as "a form in which the entrance condition composition ratio is fixed. &Quot;

In this process, the viscosity μ of the liquid corresponding to a specific temperature and pressure of a specific liquid (or a mixture of two or more) inputted, the density ρ of the liquid 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 viscosity μ of the liquid, which corresponds to the input constant, the density of the liquid 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.

In Fig. 2, when the temperature is 249 (K) and the pressure is 430 (kpa), it is impossible to select a value for the viscosity μ of the liquid.

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

That is, the temperature 249 (K) is between 248 (K) and 250 (K) and the pressure 430 (kpa) is between the pressure 420 (kpa) and the pressure 430 (kpa) .

As an example, if the values of k1 and k2 corresponding to 248 (K), 420 (kpa) and 440 (kpa) are selected and substituted into the following equation, the viscosity k3 at 249 (kpa) Can be simply calculated.

k3 = k1 + {(k2-k1) / (440-420)} * (440-430)

Similarly, when k4 and k5 corresponding to 250 (k), 420 (kpa) and 440 (kpa) are selected and substituted into the above equation,

k6 = k4 + {(k5-k4) / (440-420)} * (440-430)

The value of viscosity k6 at 132 (kPa) can be obtained.

Using the values of k3 and k6, the values of viscosity k7 at 249 (k) and 430 (kpa) can be obtained, which can be obtained simply by using the above-described method.

That is, k7 = k3 + {(k6-k3) / (440-420)} * (440-430).

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

In the present invention, as described above, in the case of pressure, there is no influence on the density and the viscosity coefficient change. However, when the pressure increases near the critical pressure, the deviation increases and the error is less than about 1%.

Therefore, when the pressure is less than the critical pressure for a liquid to be measured, only the measured temperature T is input to obtain the pressure P, and the density and viscosity, which are input constants, are input in the input constant database, .

The present invention is referred to as an input constant input process in the case where the above process is less than the critical pressure for the liquid to be measured.

Therefore, if the temperature of the liquid is measured and input,

P = aT ³ + bT + cT + d is defined as ^2.

Where a, b, c, and d are constants, which are values experimentally determined to obtain the pressure for a particular liquid.

Therefore, the constant values of a, b, c, and d are different depending on the kind of liquid, and are input in advance for each kind of liquid.

Therefore, when the flow rate is measured, the measured temperature value is input below the critical pressure, and the pressure is calculated.

That is, when the pressure of the user is less than the critical pressure, the pressure sensor can be removed and the flow rate can be measured only by the temperature.

The calculation operation for obtaining the pressure described above can be easily performed in the operation program of the central processing unit mounted in the present invention.

As described above, in the present invention, when the pressure is less than the critical pressure of the liquid, the density and the viscosity coefficient according to the temperature and pressure can be obtained from the input constant database by calculating the pressure only by measuring the temperature.

(2) In the present invention, as described above, a process is performed in which an input constant applicable to a case where the ratio of the mixed liquid varies with time, unlike the case where the liquid mixed in a single liquid or a fixed ratio is introduced (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 viscosity μ of the liquid, the density ρ of the liquid The process of finding the value is performed.

When the pressure is less than the critical pressure as described above, only the temperature is measured to obtain the pressure. Accordingly, the viscosity μ of the liquid, the density ρ of the liquid The process of finding the value is performed.

When the inlet condition is variable, the ratio of the content ratio (R) of the component to the liquid to be measured is measured since the component of the liquid (F1, F2) to be measured changes with time.

An apparatus for measuring the content ratio of the above components means an apparatus or means provided with a sensor capable of measuring the content of components of a liquid.

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.

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

First, the process of deriving the individual input constants for the liquids F1 and F2 whose component contents vary in the same manner as in the derivation of the input constants in the above-mentioned "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 or the like as described above, the input constant for F1 and F2 is derived.

The input constants (viscosity μ of liquid and density ρ of liquid) for F1 and F2 thus derived are assumed to be 100% individually.

Therefore, in order to derive a single input constant for such a mixed liquid, a single input constant ([mu], [pound]) is derived by multiplying the above-described component content ratio.

That is, in the above example, a corrected single input constant (μ, ρ) that can be seen to be the same as a single liquid (F) when F1 (μ, ρ) * R1 + F2 . Where R1 is the content ratio to F1 and R2 is the content ratio to F2.

Next, the process of obtaining the outflow coefficient (C) is performed.

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

(Q _m , mass flow rate) is simply inputted to the equation (1).

As shown in FIG. 5, in the present invention, the flow coefficient C is arbitrarily inputted with a specific number, and a process of obtaining a measured value of the first flow rate is performed.

The present invention preferably sets C to 0.9 to 0.9999, preferably to 0.95, to obtain a measured value of the flow rate (in this case, a tightening mechanism using a nozzle is used)

Therefore, in the case of an orifice, C is about 0.65, and the venturi is about 0.93.

In the case of using a nozzle, the above-mentioned C is inputted as 0.95, and β, dp, d, ρ The value of the first flow rate q _m1 is calculated.

Also, it is preferable that the initial effluent coefficient C is input directly to the C value as described above, but it is also possible to obtain the initial Re by setting the initial Re and calculating by the following equation. In this case, the initial Re is usually 1000000, and the input value of β is used.

When the Re value is input in this manner, a value approximate to the above-mentioned effluent coefficient C (= 0.95) is derived, and the following process may be performed in the same manner.

(Equation 2)

The above equation (2) is a formula for obtaining the discharge coefficient for the nozzle.

Therefore, in the case of using an orifice, a venturi or the like among the tightening mechanisms, other formulas may be applied.

That is, the formula for calculating the normal discharge coefficient is as follows

C = a + b (β / Re) ⁿ ------ (effluent coefficient representative equation)

a, b are constants, n is an exponent

. ≪ / RTI >

As described above, the outflow coefficient correction process used in the present invention can be performed by calculating a, b, and n from the outflow coefficient representative equation according to which of the tightening mechanisms is used, and using the outflow coefficient calculation formula according to each of the tightening mechanisms to be.

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

C value is a function of Re (Reynolds number). If Re value changes, C value changes.

Therefore, Re is obtained by the following formula,

(Equation 3)

The first flow rate q _m1 obtained above is substituted, and the value of Re is obtained when the process of inputting the viscosity (μ) of the liquid and the diameter (D) value of the pipe is performed.

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

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

(Equation 4)

When the Re value and the? Value obtained before the above equations 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 the calculation operation using the above-mentioned calculation formula of the representative coefficient of the flow coefficient.

The corrected C value [C1] obtained in the above is multiplied by the above equations (1),

And the process of calculating the value of the second flow rate (q _m2 ) is performed.

Then, when the second flow rate value is calculated, the re-corrected Re value is obtained by using the second flow rate value (q _m2 ).

Then, the re-corrected C value can be obtained by using the Re value derived from the above.

The process of correcting the outflow coefficient C is performed two to ten times.

Preferably 3 to 5 times, and the error rate of the outflow coefficient C value is remarkably eliminated by performing such a correction process.

It is possible to accurately derive the outflow coefficient C through the above-described repetition process.

In this way, when the outflow coefficient C value is accurately corrected, it is possible to measure the exact flow rate of any specific liquid.

Therefore, as described above, the outflow coefficient C derived through the correcting process for accurately obtaining the outflow coefficient C, the d and the dp derived in the previous process, and the input constant (the density of the liquid ρ) are input to the equation .

Therefore, as described above, the outflow coefficient C derived through the correcting process for accurately obtaining the outflow coefficient C, the d and the dp derived in the previous process, and the input constant (the density of the liquid ρ) are input to the equation .

(Equation 1)

Through this process, the exact mass flow (q _m ) of the flowing liquid can be obtained.

Through this process, the exact mass flow (q _m ) of the flowing liquid can be obtained.

Then, the process of obtaining the volume flow rate through the mass flow rate can be performed again.

The formula for obtaining the volume flow (q _v ) is as follows.

(q _v ) = q _m / p [m ³ / s]

Also, a process of obtaining the flow velocity of the fluid through the above volume flow rate can be performed.

The flow rate formula (V) is as follows.

[m/s]

[m / s]

The above formulas are simple expressions and can be implemented through a simple program or a computer.

Accordingly, in the present invention, the process of consistently deriving a value using a formula (or formula) used in the present invention may be performed by using an application program programmed for such a formula as described above, .

Then, a process of displaying the mass flow rate, the volume flow rate, and the flow rate is performed.

As described above, the present invention provides a method of accurately measuring the flow rate of the liquid through the above process.

The liquid flow measurement method according to the above description of the present invention may include a computer readable medium including program instructions for performing an operation implemented in a computer, a calculator, a computing unit, an information processing apparatus, or the like.

The computer-readable medium may include program instructions, data files, data structures, and the like, alone or in combination. The medium may comprise program instructions

May be those specially designed and constructed for the present invention or may be available to those skilled in the computer software.

Examples of computer-readable media include magnetic media such as hard disks, floppy disks and magnetic tape; optical media such as CD-ROMs and DVDs; magnetic media 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.

3. Application

Also, as described above, the present invention can be implemented as an application program for measuring the liquid flow rate using the above-described 2. input constant database.

As described above, the above-described process is based on a calculation procedure and an algorithm for equations such as a flow rate measurement formula for a liquid, an input constant selection and / or a calculation process, and a flow coefficient correction process.

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 flowchart showing a method of measuring the liquid flow rate in a state in which the inlet condition composition ratio is fixed, 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 liquid flow rate can be produced.

Also, FIG. 6 shows a flowchart of a method for correcting input constants in a form in which the entrance condition composition ratio is variable. When an application program implementing the algorithm for such a method is added to the application program described above, An application program for measuring the liquid flow rate in a variable form can be produced.

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 a flow measurement program that is specifically implemented using a programming language to measure the flow rate of the liquid.

4. Using the liquid flow measurement method of the present invention Tightening mechanism  Liquid flow measuring device

The present invention provides a liquid flow rate measuring apparatus or liquid flow rate measuring apparatus using a liquid flow rate measuring method described above (collectively referred to as "liquid flow rate measuring apparatus").

The liquid flow rate measuring apparatus of the present invention includes a liquid flow rate 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 10, There is provided an information processing apparatus 60 on which an application program embodying the liquid flow rate measuring method of the present invention is mounted and an input constant database 70 that can be used in the application program.

7 shows a perspective view of a liquid flow measurement window of the present invention.

The liquid flow rate measuring apparatus body of the present invention means a portion through which liquid passes and means a tubular device or apparatus to which a tightening mechanism (1, nozzle, etc.) is attached.

The pressure sensor 20 is attached to the inlet of the body and the fastening mechanism mounting portion, so that the pressure of the inlet portion of the body and the fastening mechanism mounting portion described above can be obtained.

Therefore, since the pressure difference dP can be obtained through the above-described pressure sensor, the pressure difference sensor 40 is a concept including an apparatus or a device that operates in conjunction with a pressure sensor.

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

In the present invention, the pressure sensor, the temperature sensor, and the pressure difference sensor unit are provided with transmission means for transmitting sensed measurement values.

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.

The information processing apparatus 60 according to the present invention includes a memory unit for mounting an application program implementing the above-described liquid flow measurement method of the present invention by a computer program, and a CPU, an apparatus or an apparatus .

The information processing apparatus of the present invention may be provided with a liquid selector 61 for selecting the type of liquid to be measured.

The user selects and inputs a kind of liquid or a mixed liquid by the liquid selection unit.

The liquid selection unit may further include a function selection unit 62 that can select a form in which an inlet condition composition ratio is fixed or a form in which an inlet condition composition ratio is variable.

With this function selection unit, a program to be operated in the information processing apparatus can be selected.

The information processing apparatus also includes receiving means capable of receiving the pressure, temperature, and pressure difference sensed by the pressure sensor 20, the temperature sensor 30, and 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.

It is possible to accurately measure the flow rate of the liquid by selecting or estimating the input constant for the type, pressure, temperature, and pressure difference value of the input liquid by using the input constant database.

The process by which the application measures the flow rate of the liquid has already been fully described above.

In the present invention, the information processing apparatus and the input constant database can be mounted on the display unit or provided outside the body of the liquid flowmeter.

The display unit 50 of the present invention performs the function of accurately indicating the flow rate of the measured liquid, that is, the mass flow rate, the volume flow rate, and / or the flow rate.

The liquid flow rate measuring apparatus according to the present invention includes the control unit 70 and the pressure sensor 20, the temperature sensor 30, the pressure difference sensor 40, the display unit 50, the information processing apparatus 60 ), The liquid selector 61, and the function selector 62, as shown in Fig.

In the present invention, the control unit is provided with an information transmission module 71 and a control reception module 72.

The information transmission module 71 refers to a device or means that is capable of transmitting measurement data measured by the above-described liquid flow rate measurement device through wired or wireless communication.

As described above, the information transmitting module adopts the technical idea to monitor the data measured by the liquid flow rate measuring device in real time, and it is preferable that the present invention can wirelessly transmit the measurement data And the like.

In the present invention, the above-mentioned wireless communication terminal means that a short distance communication means such as Bluetooth, Zigbee module or the like is adopted.

That is, the local information communication means of the present invention includes 4G, LTE, UWB, WiFi, WCDMA, USN, and IrDA modules in addition to the Bluetooth module or Zigbee module as described above. The apparatus or the means with which the present invention is directed.

Therefore, the information transmitting module is equipped with the Bluetooth module, Zigbee module, 4G, LTE, UWB, WiFi, WCDMA, USN or IrDA module.

The information transmission module can also monitor data measured by the liquid flow rate measuring device in real time in a portable communication device.

The portable communication device of the present invention is a concept including a portable communication device such as a computer, a notebook, a smart phone, a general mobile phone, a PDA, a meter or a control device having a separate communication function.

The present invention also includes a control receiving module 72 to remotely control the pressure sensor 20, the temperature sensor 30, the pressure difference sensor 40, the display unit 50, the information The liquid selector 61, and the function selector 62, as shown in FIG.

Accordingly, it is possible to select the kind of liquid to be remotely measured, select a function, and control the respective sensors.

The present invention thus makes it possible to easily select or estimate an input constant according to a specific liquid, a specific temperature, and a specific pressure by converting an input constant, which is indispensable to be input for measuring the flow rate of a liquid, A device for accurately measuring the flow rate of a liquid using a configuration is provided.

INDUSTRIAL APPLICABILITY The present invention is an extremely useful invention for an industry that produces, sells, and provides a device for measuring the flow rate of a liquid.

The present invention is also a very useful invention in the industry for measuring the flow rate of liquid.

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

1: tightening device
10: Liquid flow measurement body 20: Pressure sensor
30: Temperature sensor 40: Pressure difference sensor
50: display unit 60: information processing device equipped with a liquid flow rate measurement program
70:

Claims (6)

The process of inputting the type of liquid to be measured, the temperature (T), the pressure (P), the pressure difference (dP), the inlet diameter (D) and the diameter (d)
The input constant (the viscosity of the liquid, μ, the density of the liquid ρ A step of selecting and inputting an input constant according to the kind, temperature, and pressure of the liquid in the database,
A process in which the outflow coefficient C is corrected,
And calculating the calculated expansion coefficient, corrected outflow coefficient and pressure difference, throat diameter, diameter ratio, and density of liquid by substituting in the liquid flow rate measurement formula.
The process of inputting the kind of liquid to be measured, the temperature (T), the pressure difference (dP), the inlet diameter (D) of the tightening device flow measurement device and the diameter (d)
The process of calculating and inputting the pressure P by the input temperature T,
The input constant (the viscosity of the liquid, μ, the density of the liquid ρ A step of selecting and inputting an input constant according to the kind, temperature, and pressure of the liquid in the database,
A process in which the outflow coefficient C is corrected,
And calculating the calculated expansion coefficient, corrected outflow coefficient and pressure difference, throat diameter, diameter ratio, and density of liquid by substituting in the liquid flow rate measurement formula.
3. The method according to claim 1 or 2,
The process in which the outflow coefficient is corrected,
A process in which a specific effluent coefficient is input,
A process in which a liquid flow rate is set by an operation process according to a liquid flow rate measurement formula,
Re is the process of setting Re as an operation process according to the formula,
A process in which the outflow coefficient is corrected by calculation according to the outflow coefficient calculation formula,
Wherein the calibration process is repeated two to ten times.
3. The method according to claim 1 or 2,
A process of measuring and inputting the content ratio of the liquid to be mixed with the liquid to be measured,
Wherein a single input constant is derived through an operation using the input content ratio and the input constant of the liquid to be measured.
A liquid flow measurement program, implemented using a programming language, according to any one of claims 1 to 4.
A liquid flow measurement body 10 and a pressure sensor 20, a temperature sensor 30, a pressure difference sensor 40 and a display unit 50 are mounted on the body,
An information processing apparatus (60) equipped with the liquid flow rate measurement program of claim 6 and a predetermined input constant database (70) usable in the liquid flow rate measurement program.

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