KR20180061793A - Correction System and Method for Low Power Pressure and Temperature Calibrating embedded Remote Measuring Gas Meter - Google Patents

Abstract

The present invention relates to a correction system of a gas meter for remote metering installed with a low power temperature-pressure correction function, and a method thereof. The present invention is able to remotely meter a gas such that real-time monitoring can be implemented. Since an installation location of a gas meter is not limited, product manufacturing costs can be reduced, installation costs and maintenance costs can be reduced, and a low cost and supplemental gas meter can be provided. By selectively applying a correction algorithm in accordance with a usage state of the gas meter, the correction function can be improved. Since the correction function and a temperature/pressure sensing function are integrated, construction of the system can be facilitated.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a calibration system for a remote meter reading gas meter equipped with a low-power temperature and pressure correction function,

The present invention relates to a calibration system and method for a remote meter reading gas meter equipped with a low power temperature and pressure correction function, and more particularly, The present invention relates to a calibration system for a remote meter reading gas meter equipped with a low power temperature and pressure correction function and a method thereof.

City gas is used for cooking, heating and industrial use by 15.5 million households, 74.5% of all households. The increase in city gas usage and the improvement of gas suppliers' services are continuing to raise city gas rates.

FIG. 1 is a graph explaining the rate of increase in city gas rates. When the city gas rate (970 won / m ³ ) is increased by 11% from 2010 to 2012 and the city gas rate is increased at the same rate every year, To about 1430 yuan / m ³ in the case of the US dollar.

The gas supplier supplies the city gas at 0 ° C and 1 atm. Depending on seasonal factors and the gas meter installation environment, the city gas metering volume differs from the supply volume.

Actually, according to Boyle-Charles's law, the gas expands by 0.37% each time the temperature rises by about 1 ° C. Therefore, the city gas supplied at 0 ° C and 1 atm is affected by the adherence environment of the gas meter and seasonal factors As the ambient temperature increases by 1 ° C, the gas charge is 0.37% more than the actual usage.

Urban gas is generally measured at room temperature, and the gas volume expands according to the temperature rise and the atmospheric pressure, and the actual usage is overcharged. In the domestic gas meter, the supply volume correction by the temperature pressure is not applied and the reliability of the metering volume is inevitably degraded.

In this way, in order to solve the problem that the city gas charge is overcharged due to the metering error, the city gas company is compensated by the pressure correction according to the measure for ensuring the adequacy of gas supply measurement in the Enforcement Decree of City Gas Business Act (Presidential Decree No. 520) And imposes a charge by the amount of the inspection.

2 is a view for explaining a gas meter to which a conventional stand-alone type pressure compensator is attached.

2, by providing a temperature sensor 11 and a pressure sensor 12 on one side of the gas meter 10 and attaching the pressure compensator re-reading sensor 13 to the outside of the gas meter 10 And the metering volume reliability can be improved.

The gas meter with this independent type pressure compensator is forced to increase the product price due to the redundant installation of hardware (HR sensor, PCB, LCD), and due to the adoption of the detachable sensor, the accuracy due to the calibration error of the sensor characteristic and the amplifier characteristic There is a problem that the deterioration factor is latent. In addition, since most gas meters use a local communication network such as Wi-Fi, Zigbee, and Bluetooth, it is impossible to perform remote meter reading and a separate communication module for internet connection is required for remote meter reading. There is a problem that it can be raised.

Korean Patent No. 0811239 "Temperature Pressure Error Correction Device for Capacity City Gas Meter with Automatic Meter Reading Function"

The present invention relates to a calibration of a gas meter for remote meter reading equipped with a low-power temperature and pressure correction function that can reliably assure gas measurement by selectively applying a correction algorithm according to the use state of the gas meter System and method therefor.

Among the embodiments, a calibration system for a remote meter reading gas meter equipped with a low power temperature and pressure correction function performs wired or wireless communication, measures the flow rate, temperature and pressure of a gas to provide each measured value, A plurality of gas meters for performing a correction algorithm for correcting the gas amount using at least one of temperature, pressure, and pressure; A reference terminal connected to the plurality of gas meters by wire or wirelessly and providing reference values necessary for performing the correction algorithm; And a calibration algorithm using at least one of a flow rate, a temperature, and a pressure according to a usage environment of each gas meter, And a work terminal performing the setting function of the correction algorithm so that the determined correction algorithm is applied to the gas meter.

Among the embodiments, a method for calibrating a remote meter gas meter equipped with a low-power temperature and pressure correction function comprises the steps of measuring the flow rate, temperature and pressure of a gas in a gas meter and providing each measured value; A correction algorithm for correcting the flow rate difference according to the flow rate, a correction algorithm for correcting the gas amount according to the temperature, a correction algorithm for correcting the gas amount according to the temperature and the pressure, a gas amount correction Selecting at least one correction algorithm according to the usage environment of each gas meter among the correction algorithms; And performing a setting function of the correction algorithm of the gas meter so that the selected correction algorithm is applied to the corresponding gas meter.

At this time, the correction algorithm for correcting the flow measurement difference according to the flow rate divides the maximum capacity value and the minimum capacity value of the gas meter into a plurality of steps and corrects the gas amount when the correction coefficient according to the gas flow rate is irregular A linear correction algorithm for measuring the flow rate through the gas meter and correcting the gas amount by using a linear function according to the flow rate, and a flow rate measuring device for measuring the flow rate through the gas meter, And a nonlinear correction algorithm for correcting the gas amount.

The calibration system and method of the remote meter reading gas meter equipped with the low power temperature and pressure correction function of the present invention can perform real time monitoring by wireless remote gas meter inspection and are not restricted by the installation position of the gas meter, The cost can be reduced, and the installation cost and the maintenance cost can be reduced.

In addition, the present invention can provide a low-cost and low-grade gas meter, and can improve the correction function by selectively applying a correction algorithm according to the use state of the gas meter. Since the correction function and the temperature / pressure sensing function are integrated, This has the effect of being easy.

1 is a graph for explaining the city gas rate increase rate.
2 is a view for explaining a gas meter to which a conventional stand-alone type pressure compensator is attached.
3 is a view for explaining a gas meter for remote meter reading equipped with a low power temperature pressure correction function according to an embodiment of the present invention.
4 is a view for explaining a correction system for a gas meter for remote meter reading equipped with a low-power temperature and pressure correction function according to an embodiment of the present invention.
5 is a view for explaining a method of calibrating a gas meter for remote meter reading equipped with a low-power temperature and pressure correction function according to an embodiment of the present invention.
6 is a graph for explaining the stepwise correction algorithm of FIG.
FIG. 7 is a graph illustrating a case where the ideal gas state equation is applied to the temperature / pressure correction algorithm of FIG. 5 regardless of the gas usage state.
FIG. 8 is a graph for explaining a case where the temperature / pressure correction algorithm of FIG. 5 is applied to the molar composition analysis and the state equation according to physical properties according to the gas use state.

The description of the present invention is merely an example for structural or functional explanation, and the scope of the present invention should not be construed as being limited by the embodiments described in the text. That is, the embodiments are to be construed as being variously embodied and having various forms, so that the scope of the present invention should be understood to include equivalents capable of realizing technical ideas. Also, the purpose or effect of the present invention should not be construed as limiting the scope of the present invention, since it does not mean that a specific embodiment should include all or only such effect.

Meanwhile, the meaning of the terms described in the present invention should be understood as follows.

The terms "first "," second ", and the like are intended to distinguish one element from another, and the scope of the right should not be limited by these terms. For example, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

It is to be understood that when an element is referred to as being "connected" to another element, it may be directly connected to the other element, but there may be other elements in between. On the other hand, when an element is referred to as being "directly connected" to another element, it should be understood that there are no other elements in between. On the other hand, other expressions that describe the relationship between components, such as "between" and "between" or "neighboring to" and "directly adjacent to" should be interpreted as well.

It should be understood that the singular " include "or" have "are to be construed as including a stated feature, number, step, operation, component, It is to be understood that the combination is intended to specify that it does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

In each step, the identification code (e.g., a, b, c, etc.) is used for convenience of explanation, the identification code does not describe the order of each step, Unless otherwise stated, it may occur differently from the stated order. That is, each step may occur in the same order as described, may be performed substantially concurrently, or may be performed in reverse order.

All terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise defined. Commonly used predefined terms should be interpreted to be consistent with the meanings in the context of the related art and can not be interpreted as having ideal or overly formal meaning unless explicitly defined in the present invention.

3 is a view for explaining a gas meter for remote meter reading equipped with a low power temperature pressure correction function according to an embodiment of the present invention.

3, the remote meter reading gas meter 100 equipped with the low power temperature and pressure correction function includes a pressure sensor 110, a temperature sensor 120, a volume calculation module 130, a power supply module 140, Function module 150 and a microcomputer 160. [

The pressure sensor 110 senses the pressure of the city gas, and the temperature sensor 120 senses the temperature of the city gas.

The volume calculation module 130 applies the use environment optimal state equation algorithm, and the power supply module 140 supplies power necessary for driving the gas meter 100.

The communication function module 150 enables remote meter reading or remote control of the gas meter 100 through a local area network or an RF communication network.

The microcomputer 160 includes algorithms for performing self diagnosis and alarm functions such as leakage, opening and backflow, wired / wireless sleep / wakeup function, supply gas metering and control function, temperature / pressure correction function, It is built-in. The microcomputer 160 corrects the temperature and the pressure sensed by the pressure sensor 110 and the temperature sensor 120, calculates the gas volume, and calculates the charge.

The microcomputer 160 includes a power control algorithm for stopping power supply to all the peripheral devices in the sleep mode for low power control and a correction algorithm for correcting the gas flow rate according to the gas flow rate, temperature, and pressure.

The microcomputer 160 can perform a function of interlocking with the surrounding fire detectors and the gas leak detectors through the communication function module 140.

At this time, the microcomputer 160 includes a memory (not shown) for storing various information such as algorithms, diagnostic information, volume calculation result information, and alarm information.

4 is a view for explaining a correction system for a gas meter for remote meter reading equipped with a low-power temperature and pressure correction function according to an embodiment of the present invention.

4, the calibration system for the remote meter reading gas meter equipped with the low-power temperature and pressure correction function includes n gas meters 100 installed in a nationwide manner, a reference terminal 200, and a work terminal 300 do.

The reference terminal 200 is wired or wirelessly connected to the gas meter 100, and provides reference values necessary for performing the calibration algorithm.

The working terminal 300 determines a calibration algorithm suitable for each gas meter 100 in conjunction with the gas meter 100 and the reference terminal 200 and transmits the determined calibration algorithm to the microcomputer 160 ) ≪ / RTI >

To do this, the workstation 300 executes a calibration algorithm selection application and the calibration algorithm selection application performs step-by-step calibration algorithms, linear calibration algorithms, and nonlinear calibration algorithms so as to apply the optimal state equations according to the usage environment of the gas meter 100 And selects one of the correction algorithms.

If the calibration algorithm selection application is stored in the memory of the gas meter 100 and the gas meter 100 is selected according to its own calibration algorithm without going through the working terminal 300 when it is executed according to an external remote control command, .

The work terminal 300 may be a communication device capable of network connection such as a desktop computer, a laptop computer, a smart phone, a PDA (Personal Digital Assistant), a PMP (Portable Multimedia Player), a navigation terminal, There is no limit to the number.

The gas meter 100 includes a gas supply company, an intelligent home network system, an Internet (IoT, Internet of Things) system, a management server for integrally managing the gas meter 100 and the like through the communication function module 140 Can be connected.

At this time, the management server manages the serial number, installation information (time, place, worker, etc.) of the gas meter 100, and performs functions such as maintenance plan and life prediction through the self diagnosis function of each gas meter 100 And can perform the functions of providing and updating correction algorithm selection applications, and the like.

5 is a view for explaining a calibration method for a remote meter reading gas meter equipped with a low-power temperature and pressure correction function according to an embodiment of the present invention, FIG. 6 is a graph for explaining the stepwise calibration algorithm of FIG. FIG. 8 is a graph illustrating the temperature / pressure correction algorithm of FIG. 5, in which the ideal gas state equation is applied regardless of the gas use state. FIG. And graphs for explaining the case where the state equations according to the physical properties are applied.

The gas meter measures the flow rate by mechanical means such as diaphragm, rotary method, turbine method and the like. The flow rate (volume) of the gas varies depending on the flow rate, pressure, and temperature at the time of measurement. In order to accurately measure the flow rate, it is necessary to correct the above parameters.

5 to 8, the correction algorithm selection application divides the gas meter 100 into sizes according to capacity, and recalls the maximum capacity value Q _max and the minimum capacity value Q _min of the gas meter from the memory .

The maximum capacity value (Q _max ) and minimum capacity value (Q _min ) are set in the memory according to the gas meters (G2.5, G4, G6). That is, G2.5 is _{Q min = 25 l / h,} Q max = 4000 l / h, G4 is _{Q min = 405 l / h,} Q max = 6000 l / h, G6 is Q _min = 25 l / h, Q _max = 4000 l / h.

The correction algorithm selection application selects any one of a stepwise correction algorithm, a linear correction algorithm, and a nonlinear algorithm according to the flow rate.

The method of correcting the measured value of the gas meter according to the above flow velocity, pressure and temperature variables includes a stepwise correction method according to the flow rate (stepwise correction algorithm) and a linear function (y = ax + b) There is a method (linear correction algorithm) that calibrates and a method that corrects it with a quadratic function (y = ax2 + bx + c) according to the flow rate (nonlinear correction algorithm).

At this time, the correction algorithm can be applied to a method of correcting for each variable of the flow velocity, temperature, and pressure and a method of correcting for all variables.

First, the method of correcting according to the flow rate is a method of correcting by applying the actual measurement value. Second, the method of correcting according to temperature and pressure is a method of correcting the gas itself. Third, This is a method of correcting the change of the physical properties of the material.

Here, the method of correcting according to temperature and pressure includes a method using an ideal gas equation (PV = nRT), a method using an AGA8-92DC state equation (molar composition analysis) (KS I ISO 12213-2), a SGERG- There is a way of applying the equation (using physical characteristics) (KS I ISO 12213-3). On the other hand, the method of correcting the change of the physical properties of the material according to the temperature and the pressure is a method of correcting by applying the temperature characteristic coefficient of the material and a method of correcting by applying the pressure characteristic coefficient of the material according to the pressure.

As shown in FIG. 6, the stepwise correction algorithm applies a stepwise correction algorithm when the correction coefficient according to the flow velocity of the gas is irregular, and the stepwise correction algorithm applies a minimum correction coefficient between the maximum capacitance value Q _max and the minimum displacement value Q _min to at least 2 Step to step 8, and the flow characteristics according to the flow rate are measured for each of the thus-identified steps to determine the value of the flow correction coefficient, and the determined flow correction coefficient is stored in the memory. At this time, the correction coefficient calculation method uses the average value of the flow velocity data measured 3 to 10 times.

)로 보정계수를 산출하는 선형 보정 알고리즘을 선택하고, 가스의 유속에 대한 측정값이 비선형적 특징으로 갖고 있으면 2차함수로 보정 계수를 산출하는 비선형 보정 알고리즘을 선택한다. 여기서 1차 함수특성을 따르는 경우에 y = ax + b의 함수 에서 x는 유속에 해당하며, y는 유량을 보정하여 주는 보정계수의 값이 된다. If the measured value of the gas flow rate has a linear characteristic, then a linear function (

), And selects a nonlinear correction algorithm that calculates a correction coefficient with a quadratic function if the measured value of the gas flow rate has a nonlinear characteristic. Here, in the function of y = ax + b , x corresponds to the flow rate, and y is the value of the correction coefficient for correcting the flow rate.

On the other hand, the temperature / pressure correction algorithm may proceed to the secondary correction algorithm after any one of the stepwise correction algorithm, the linear algorithm, and the nonlinear algorithm is performed first. However, in some cases, after the temperature / pressure correction algorithm is performed first, any one of the stepwise correction algorithm, the linear algorithm, and the nonlinear algorithm may proceed to the secondary correction algorithm.

In this case, the temperature / pressure correction algorithm uses the ideal gas equation according to whether the gas is in the low-pressure setting range or the compression method using the molar composition analysis (AGA8-92DC equation of state) (The SGERG-88 state equation) can be applied to the calculation.

The low pressure setting range is -10Kpa to + 10Kpa. Apply the ideal gas equation if the gas is in the low pressure setting range, and apply the AGA8-92DC state equation / SGERG-88 state equation when the low pressure setting range is exceeded.

If the ideal gas equation is applied even when the pressure is out of the set range, it can be seen that an error of 0.2-0.3% occurs as shown in FIGS. 7 and 8.

The compression factor according to the use temperature and pressure environment of the gas is calculated by applying the KS I ISO standard. The compression factor is calculated using the method of calculating the compression factor using the molar composition analysis (AGA8-92DC equation of state) (SGERG-88 state equation).

First, the AGA8-92DC equation of state is as shown in Equation (1) below, and the application range for the pipeline quality gas is defined as follows.

은 몰 밀도(단위 부피당 몰),

은 환산 밀도,

은 상수,

은 온도와 가스 조성의 함수인 상태 방정식 계수이다.In Equation (1), Z is a compression factor, B is a second specific coefficient,

(Mol per unit volume), < RTI ID = 0.0 >

Is the converted density,

The constant,

Is a state equation coefficient that is a function of temperature and gas composition.

The application range of the AGA8-92DC equation of state is: absolute pressure 0Mpa ≤ ρ ≤ 12Mpa, temperature 263K ≤ T ≤ 338K, total calorific value 30MJ · m ^-3 ≤ H _s ≤ 45MJ · m ^-3 , relative density 0.55 ≤ d ? 0.80.

Next, the SGERG-88 state equation is as shown in Equation (2) below, and the application range for the pipeline quality gas is defined as follows.

은 몰 밀도로서 수학식 3을 통해 구하고,

이다. In Equation (2), B and C are a function of input variables such as the high calorific value (H _s ), the relative density d, the contents of the combustible non-hydrocarbon components CO ₂ and H ₂ contained in the mixed gas and the inert component, At this time,

Is obtained by the formula (3) as the molar density,

to be.

The SGERG-88 state equation applies to absolute pressures of 0Mpa ≤ ρ ≤ 12Mpa, temperature of 263K ≤ T ≤ 338K, carbon dioxide mole fraction of 0 ≤ X _CO2 ≤ 0.20, the molar fraction of hydrogen is 0 ≤ X _H2 ≤ 0.10, the high calorific value is 30 MJ · m ^-3 ≤ H _s ≤ 45 MJ · m ^-3 , and the relative density is 0.55 ≤ d ≤ 0.80.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention as defined by the following claims It can be understood that

100: Gas meter 200: Reference terminal
300: worker terminal

Claims (3)

A plurality of gases that perform wired or wireless communications and that perform calibration algorithms that measure the flow rate, temperature, and pressure of the gas to provide respective measurements and correct the gas volume using at least one of a flow rate, temperature, Meter;
A reference terminal connected to the plurality of gas meters by wire or wirelessly and providing reference values necessary for performing the correction algorithm; And
Determining a correction algorithm using at least one of a flow rate, a temperature, and a pressure according to a usage environment of each gas meter, receiving the measured values of flow rate, temperature, and pressure for each gas meter in cooperation with the gas meter and the reference terminal, And a working terminal for performing a setting function of the correction algorithm so that the determined correction algorithm is applied to the gas meter.
Measuring the flow rate, temperature and pressure of the gas in the gas meter to provide each measured value;
A correction algorithm for correcting the flow rate difference according to the flow rate, a correction algorithm for correcting the gas amount according to the temperature, a correction algorithm for correcting the gas amount according to the temperature and the pressure, a gas amount correction Selecting at least one correction algorithm according to the usage environment of each gas meter among the correction algorithms; And
And performing a setting function of a correction algorithm of the gas meter so that the selected correction algorithm is applied to the corresponding gas meter.
3. The method of claim 2,
The correction algorithm for correcting the flow measurement difference according to the flow rate,
A step-by-step correction algorithm for correcting the gas amount by dividing the maximum capacity value and the minimum capacity value of the gas meter into a plurality of steps when the correction coefficient according to the gas flow rate is irregular; And a nonlinear correction algorithm for measuring a flow rate through the gas meter and correcting the gas amount by using a quadratic function according to the flow rate, characterized by comprising a linear correction algorithm for correcting the gas amount using a linear function according to A calibration method of a gas meter for remote meter reading equipped with a pressure correction function.

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