KR101215853B1 - Apparatus for measuring emission of gas and method for the same - Google Patents

Abstract

Disclosed are a gas emission measuring apparatus and a method for simultaneously measuring the flow rate and concentration of a particular gas with one device. The gas emission measuring apparatus may include a gas detection unit configured to emit light having a wavelength absorbed by a specific gas to be measured among mixed gases having at least one gas mixed therein, and to detect the emitted light and provide a detection signal corresponding to the detected light amount; In order to measure the flow velocity of the specific gas, the concentration of the specific gas is calculated based on the first detection signal provided from the gas disturbance unit and the gas detector which disturb the flow of the mixed gas, and then the driving of the gas disturbance unit is controlled to control the flow of the mixed gas. And a controller for disturbing and calculating the flow rate of the specific gas based on the second detection signal provided from the gas detector, and then calculating the discharge amount of the specific gas based on the calculated concentration and flow rate of the specific gas. Therefore, the gas emission measuring apparatus can be manufactured simply, and the portability and measurement convenience are improved.

Description

Apparatus and method for measuring gas emissions {APPARATUS FOR MEASURING EMISSION OF GAS AND METHOD FOR THE SAME}

The present invention relates to a gas emission measurement, and more particularly, to a gas emission measurement apparatus and method for measuring the gas flow rate and gas concentration of a particular gas in a mixed gas using one device.

In general, the flow rate measurement of the gas discharged from the chimney, etc. is measured by measuring the gas flow rate to measure the distance traveled per unit time of the gas and multiply the cross section at the point where the flow rate is measured.

In addition, in order to measure the emission of only a specific gas when several kinds of gases are mixed, the flow rate of the total gas discharged is first measured, and then the concentration of the specific gas to be measured is measured by measuring the concentration of the specific gas. Calculate the emissions. Here, the concentration of the specific gas can be measured by obtaining the ratio of the volume of the specific gas to the volume of the entire gas.

In addition, as one of the methods for measuring the concentration of gas, a non-dispersive infrared method using a characteristic in which a predetermined gas absorbs light of a specific wavelength is used.

1 shows a light absorption spectrum of gas molecules, for example, carbon dioxide absorbs light having a wavelength of 4.26 μm, and methane has light absorbing light having a wavelength of 3.3 μm.

As shown in FIG. 1, the non-dispersive infrared method measures concentration using a characteristic that each gas molecule absorbs light having a specific wavelength in proportion to the concentration. For this purpose, a light source for emitting light in a wavelength band absorbed by a gas to be measured and a light detector for detecting light emitted from the light source are required. In addition, the path from which the light emitted from the light source reaches the photo detector is called an optical path. When gas molecules are positioned on the optical path, part of the emitted light is absorbed by the gas molecules, so that the amount of light detected through the photo detector is reduced. The amount of light absorbed becomes proportional to the concentration of the gas. The method of measuring the concentration of gas using a non-dispersive infrared method has an advantage of high measurement reliability.

However, conventionally, as described above, the gas flow rate measurement technique and the gas concentration measurement technique were independently applied to measure the emission of a specific gas in the mixed gas. For this purpose, a gas flow meter and a gas concentration meter were used independently. Therefore, a plurality of equipments are required to measure gas emissions, and each measuring instrument needs to measure gas flow rate and gas concentration separately using the respective equipment, and then calculate emissions of a specific gas based thereon. Since it must be provided separately, it requires a high cost and has a disadvantage that each meter must be managed after each one.

An object of the present invention for overcoming the above disadvantages is to provide a gas emission measuring apparatus that can measure the flow rate and concentration of a particular gas at the same time in a single device in an environment in which several types of gases are mixed and discharged.

In addition, another object of the present invention is to provide a gas emission measurement method that can measure the flow rate and concentration of a particular gas at the same time in a single device in an environment in which several types of gases are mixed.

Technical problems of the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the following description.

Gas emission measuring apparatus according to an aspect of the present invention for achieving the above object of the present invention, emits light of a wavelength absorbed by a particular gas to be measured in the mixed gas mixed with at least one gas, the emission A gas detector which detects the light and provides a detection signal corresponding to the detected amount of light, a gas disturber which disturbs the flow of the mixed gas to measure the flow velocity of the specific gas, and a first detection signal provided by the gas detector After calculating the concentration of the specific gas based on the control method, controlling the driving of the gas disturbing unit to disturb the flow of the mixed gas, and calculating a flow rate of the specific gas based on the second detection signal provided from the gas detecting unit. And a control unit for calculating the discharge amount of the specific gas based on the calculated concentration and flow rate of the specific gas.

The gas disturbance unit may input an instruction gas under the control of the controller.

The controller may receive a voltage as a first detection signal from the gas detector and convert the voltage into a concentration of the specific gas by using a via-lambert function.

The gas detector may include a first light source that emits light having a wavelength absorbed by the specific gas, and a first detection signal that detects light emitted from the first light source and provides a first detection signal corresponding to the detected light amount to the controller. The photodetector, a second light source emitting light having a wavelength absorbed by the specific gas, and light emitted from the second light source may be detected and a second detection signal corresponding to the detected light amount may be provided to the controller.

The first optical path between the first light source and the first photodetector and the second optical path between the second light source and the second photodetector may be spaced apart by a predetermined distance to be parallel to each other and to be perpendicular to the flow of the mixed gas. Can be.

The control unit calculates the concentration of the specific gas, initializes time, controls the gas disturbing unit, injects an indication gas, and is a peak value of a first voltage provided from the first photodetector and a peak time point of the first voltage. After detecting a first time, after detecting a peak time of a second voltage provided from the second photodetector and a second time point of the peak time of the second voltage according to the flow of the indicating gas, the first time and The flow rate of the specific gas may be measured using the difference between the second time and the predetermined distance.

In addition, the gas emission measurement method according to an aspect of the present invention for achieving another object of the present invention, in the gas emission measurement method for measuring the emission of a specific gas of the mixed gas in which at least one gas is mixed, the specific Calculating the concentration of the specific gas by emitting light having a wavelength absorbed by the gas to the mixed gas and detecting the emitted light; and directing an indication gas to an exhaust pipe through which the mixed gas flows to disturb the flow of the mixed gas. Calculating a flow rate of the specific gas based on the step of inputting, a peak value of the voltage detected in correspondence with the flow of the indicating gas, and a peak time point of the voltage; and calculating the flow rate of the specific gas based on the calculated concentration and flow rate. Calculating the emissions.

The calculating of the concentration of the specific gas may include: emitting light having a wavelength absorbed by the specific gas to the mixed gas; detecting the emitted light and obtaining a voltage corresponding to the detected amount of light; and via Converting the voltage to a concentration of the particular gas using a Lambert function.

Injecting an indication gas to disturb the flow of the mixed gas may include initializing time.

The calculating of the flow rate of the specific gas may include measuring a peak value of a first voltage provided as the indicator gas flows through a first optical path and a first time that is a peak time point of the first voltage, and the indication Measuring a peak time of the second voltage provided as the gas flows through the second light path spaced a predetermined distance from the first light path, and a second time which is a peak time point of the second voltage; The method may include measuring a flow rate of the specific gas by using a difference of a second time and the predetermined distance.

The gas emission measuring method derives a relationship between the diffusion rate of the specific gas and the diffusion rate of the indication gas after the step of calculating the flow rate of the specific gas when the indication gas is a gas of a different type from the specific gas. The method may further include calculating a flow rate of the specific gas using the derived relationship.

According to the gas emission measuring apparatus and the method as described above, by detecting the voltage corresponding to the amount of light transmitted through the specific gas by using the light of the wavelength absorbed by the specific gas to be measured and then using the Beer-Lambert theory The concentration of the gas is calculated, the indication gas is introduced, and the flow rate is calculated based on the peak value and time of the voltage detected as the indication gas traverses two optical paths spaced a predetermined distance apart. Then, the hourly emissions of a particular gas are calculated using the calculated concentrations and flow rates.

In addition, the gas emission measuring apparatus and method according to an embodiment of the present invention, rather than simply combining the gas flow meter and the gas concentration meter while maintaining independent characteristics, respectively, the flow rate and concentration of the gas using a single measurement technology It is to measure the flow rate of the gas and the concentration of gas at the same time.

Therefore, the flow rate and concentration of a specific gas can be measured simultaneously with only one measuring device, the measuring device can be easily manufactured, and it is convenient to carry, easy to measure gas emissions, and the maintenance cost can be reduced.

The gas emission measuring apparatus and the method according to an embodiment of the present invention may be applied to, for example, a chimney tele-monitoring system (TMS) or a vehicle exhaust gas measuring apparatus.

1 shows the light absorption spectrum of gas molecules.
2 is a conceptual view for explaining a method of measuring the flow rate of the gas discharged through the chimney.
3 is a conceptual diagram for explaining the beer-lambert theory.
4 is a conceptual diagram for explaining a gas flow rate measurement.
5 is a conceptual diagram for explaining a method of simultaneously measuring the concentration and the flow rate of a specific gas.
6 is a block diagram showing the configuration of a gas emission measuring apparatus according to an embodiment of the present invention.
It is a conceptual diagram for demonstrating operation | movement of the gas emission measuring apparatus shown in FIG.
8 is a flowchart illustrating a gas emission measuring method according to an exemplary embodiment of the present invention.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail.

It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, 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. And / or < / RTI > includes any combination of a plurality of related listed items or any of a plurality of related listed items.

When a component is referred to as being "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but it may be understood that other components may be present in between. Should be. On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the relevant art and are to be interpreted in an ideal or overly formal sense unless explicitly defined in the present application Do not.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In order to facilitate the understanding of the present invention, the same reference numerals are used for the same constituent elements in the drawings and redundant explanations for the same constituent elements are omitted.

Hereinafter, in order to understand the technique and operating principle of the gas emission measuring apparatus and method according to an embodiment of the present invention, for example, measuring the emission of carbon dioxide in various types of gas discharged from the chimney The theoretical analysis method applied to the gas emission measurement device and the gas flow rate measurement method according to the present invention will be described.

1. Calculation of gas emissions

If fossil fuels are burned using the atmosphere, the gases produced after combustion are carbon dioxide and water vapor, nitrogen not involved in combustion, residual oxygen after combustion, and if the combustion is carried out at high temperature, some nitrogen is also burned and nitrates, incomplete combustion. Various types of gases, such as carbon monoxide, are emitted through the chimneys. As described above, the emission of carbon dioxide among the various gases emitted is calculated by measuring the ratio (or concentration) of carbon dioxide in the total gas emissions.

2 is a conceptual view for explaining a method of measuring the flow rate of the gas discharged through the chimney.

Referring to FIG. 2, the flow rate of gas per unit time may be measured by multiplying the cross-sectional area A of the chimney after measuring the flow rate v of the gas. If the cross-sectional area A of the chimney is known in advance, the flow rate of the gas can be easily measured by measuring the flow rate v of the gas.

In addition, a method of measuring carbon dioxide emission in an environment in which various types of gases are mixed may be calculated by measuring the concentration of carbon dioxide in the total gas flow rate and then multiplying the total gas flow rate by the ratio of carbon dioxide.

That is, the discharge amount C of the specific gas during the time t may be calculated by multiplying the concentration N of the specific gas by the distance L traveled during the time t and the cross-sectional area A of the exhaust pipe from which the gas is discharged.

2. Beer-Lambert theory

Beer-Lambert theory is an analysis of the characteristics of gas molecules absorbing light of a certain wavelength, and defines the correlation between gas concentration and the amount of transmitted light when the gas molecules absorb light of a certain wavelength.

Light emitted from the light source reaches a photo detector through a constant light path. When gas molecules are located on the optical path, some of the light is absorbed by the gas molecules and some is transmitted to reach the photo detector. Here, the amount of light absorbed by the gas molecules is proportional to the gas concentration, which means that the amount of light transmitted without being absorbed by the gas molecules is inversely proportional to the gas concentration.

3 is a conceptual diagram for explaining the beer-lambert theory.

Referring to FIG. 3, the photo detector outputs a voltage V corresponding to the detected light amount. The output voltage V is derived as a function of the gas concentration X. In FIG. 3, Vo denotes a voltage when the gas concentration is 0, L denotes a length of an optical path, and b denotes an eigenvalue representing light absorption of one gas molecule.

In general, the amount of light reaching the photo detector is linearly proportional to the voltage output by the photo detector. Therefore, it can be said that the voltage V output from the photodetector is equal to the amount of light reaching the photodetector.

In addition, the light source emits a wavelength absorbed by the gas molecules and the photodetector only detects light of that wavelength. For example, in order to detect carbon dioxide, the light source emits light having a wavelength of 4.26 μm, and when methane is detected, the light source emits light having a wavelength of 3.3 μm, and the light detector detects only light having the corresponding wavelength. Therefore, the kind of gas to be detected can be selected by selecting the detection wavelength of a photodetector. Here, the detection wavelength of the photodetector can be selected by applying an optical filter that transmits only light of the wavelength.

3. Detection of gas concentration

Detection of gas concentration can be calculated using the Beer-Lambert theory. In FIG. 3, since the voltage V output by the photodetector is a function of the gas concentration X, the gas concentration is obtained by measuring the voltage V output from the photodetector and then obtaining the inverse function of the output voltage V. Can be calculated. Here, the product of the light absorptance value b of one gas molecule and the length L of the light path (that is, b × L) may be derived during the calibration using the reference concentration.

4. Measurement of gas flow rate

Knowing the cross-sectional area of the exhaust pipe (eg chimney) through which the gas is discharged, measuring the flow rate of the gas is equivalent to measuring the flow velocity of the gas. Therefore, hereinafter, a description will be given of a method of measuring a gas flow rate to replace the description of the method of measuring a gas flow rate.

4 is a conceptual diagram for explaining a gas flow rate measurement.

Referring to FIG. 4, two pairs of light sources and two pairs of light detectors are used to measure the flow rate of the gas, and the two pairs of light sources are configured to emit light of a specific wavelength absorbed by the gas molecules to measure the flow rate. Alternatively, the two pairs of photo detectors are configured to detect light of a particular wavelength absorbed by the gas molecules for which the flow rate is to be measured.

First, the light emitted from the first light source 110 reaches the first photodetector 130 via the first light path 150, and the light emitted from the second light source 120 passes through the second light path 160. And reaches the second photodetector 140. Here, the first optical path 150 and the second optical path 160 are parallel to each other and spaced apart by a distance ΔL.

The indicator gas may be the same kind of gas as the gas to be measured, and a high concentration of gas may be used, or another kind of gas capable of converting the flow rate of the gas to be measured may be used. If other species of gas are used as the indicator gas, the concentration is zero for the gas whose flow rate is to be measured. The indicating gas moves vertically with respect to the first light path 150 and the second light path 160.

The voltages output from the photo detectors 130 and 140 are connected to a measuring device capable of measuring an amount of change in voltage over time, such as an oscilloscope. For example, the first photodetector 130 is connected to the first channel CH01 of the oscilloscope and the second photodetector 140 is connected to the second channel CH02 of the oscilloscope to connect the first photodetector 130 and The voltage provided from the second photodetector 140 may be displayed.

In the measurement environment as described above, the first photodetector 150 absorbs the light emitted from the first light source 110 when the high concentration of the indicating gas passes through the first light path 150 at the first time t1. As shown in FIG. 4, the voltage outputted from is lowered, thereby outputting a voltage waveform having a convex shape downward for the first time t1 in the first channel CH01. Subsequently, even when the indicator gas passes through the second optical path 160 at the second time t2, the indicator gas absorbs light, so that the voltage output from the second photodetector 140 is also lowered. The voltage waveform convex downward at the second time t2 is output.

Therefore, Δt, which is the interval between the lowest points of the output voltages for each time t1 and t2 of the first channel CH01 and the second channel CH02, is measured and the definition of speed (speed = ΔL / Δt) is used. In this case, the moving speed of the indicating gas can be measured.

5. Simultaneous measurement of gas concentration and flow rate

When no indication gas is input in the gas flow rate measuring method shown in FIG. 4, the voltage output from the first photodetector and the second photodetector based on the via-Lambert theory as shown in FIG. It can be converted into the concentration of gas.

FIG. 5 is a conceptual view illustrating a method of simultaneously measuring concentration and flow rate of a specific gas, and for example, simultaneously measuring concentration and flow rate of carbon dioxide in a situation in which various types of gases are mixed and discharged.

Referring to FIG. 5, the light emitted from the first light source 110 reaches the first photodetector 130 via the first light path 150, and the light emitted from the second light source 120 receives the second light. The second photodetector 140 is reached via the optical path 160. Here, the first light path 150 and the second light path 160 are parallel to each other, perpendicular to the discharge direction of the gas, and spaced apart from each other by ΔL.

The indicator gas is a high concentration of carbon dioxide and is discharged in the same direction as the gas emitted from the chimney, and the discharge rate is the same. When the indicating gas does not cross the first optical path 150 and the second optical path 160, the voltages V1 and V2 output from the first photodetector 130 and the second photodetector 140 are respectively. The concentration of carbon dioxide in the gas emitted from the chimney. That is, the voltage V1 output from the first photodetector 130 and the voltage V2 output from the second photodetector 140 may be converted into concentration using a via-Lambert function.

Here, when the indicator gas is introduced, the concentration of carbon dioxide is locally disturbed in the chimney, and the same concentration as that of the first channel CH01 shown in FIG. 5 at t1 at which the indicator gas passes the first optical path 150. A rise appears. In addition, the same concentration as that of the second channel CH02 shown in FIG. 5 also occurs at t2, which is a point in time at which the indicating gas passes through the second optical path 160.

In addition, as described above, since the moving speed of the indicating gas is the same as the moving speed of carbon dioxide in the chimney, the moving speed of the indicating gas measures Δt, which is a difference between the first time t1 and the second time t2. It can calculate from v = ΔL / Δt.

As described above, by measuring the concentration of carbon dioxide discharged from the chimney without inputting the indicator gas, and calculating the discharge rate of the carbon dioxide by inputting the indicator gas, carbon dioxide emission is calculated.

The method of simultaneously measuring the concentration and flow rate of the gas is not limited to the measurement of the emission of carbon dioxide, and may be applied to the measurement of the emission of all gases. In addition, the above-described method is also applied to the case where a gas to be measured and a gas of a different kind are used. However, in the case of using the indicator gas of a different type from the gas to be measured, it is necessary to correct the diffusion rate depending on the molecular weight of the gas. For example, when nitrogen is used as the indicator gas in the method shown in FIG. 5, since nitrogen is lighter than carbon dioxide, the diffusion rate is faster than that of carbon dioxide at the same temperature. Here, the relationship between the diffusion rate of nitrogen and the carbon dioxide diffusion rate is derived by the gas state equation.

If the temperature is the same (thermal equilibrium), according to the law of entropy, the energy of the gas molecules are the same regardless of their kind. From this, the relationship between the diffusion rate of nitrogen and carbon dioxide can be derived. For example, the energy of nitrogen is E ₁ , the energy of carbon dioxide is E ₂ , the diffusion rate of nitrogen is v ₁ , the diffusion rate of carbon dioxide is v ₂ , the molecular weight of nitrogen is m ₁ , and the molecular weight of carbon dioxide is m ₂ . In other words, in thermal equilibrium, the energy of nitrogen (E ₁ ) and that of carbon dioxide (E ₂ ) are the same (ie, E ₁ = E ₂ ). Equation 1 may be derived using the above characteristics.

[Equation 1]

When using nitrogen as an indicator gas in FIG. 5, the moving speed (v ₁ ) of nitrogen may be measured and the moving speed (v ₂ ) of carbon dioxide may be calculated using Equation 1 above. That is, since the molecular weight (m ₁ ) of nitrogen is 28 and the molecular weight (m ₂ ) of carbon dioxide is 44, the moving speeds of nitrogen and carbon dioxide have a relationship as shown in Equation (2).

&Quot; (2) "

When nitrogen is used as the indicator gas as described above, when the indicator gas passes through each of the optical paths 150 and 160, the concentration waveform displayed as the concentration is lowered is convex downward.

FIG. 6 is a block diagram illustrating a configuration of a gas emission measuring apparatus according to an embodiment of the present invention, and is a conceptual diagram for describing an operation of the gas emission measuring apparatus illustrated in FIG. 7.

6 and 7, the gas emission measuring apparatus includes a gas detection unit 100, a control unit 200, a gas disturbance unit 300, an input / output unit 400, a communication unit 500, and a storage unit 600. can do.

The gas detector 100 emits light having a wavelength absorbed by a specific gas to be measured in response to a control signal of the controller 200, and detects light transmitted through the specific gas to provide an electrical signal corresponding to the detected light amount. It provides to the control unit 200.

Specifically, the gas detector 100 may include a first light source 110, a first light detector 130, a second light source 120, and a second light detector 140, and the first light source 110. ) And the second light source 120 emit light of a wavelength band absorbed by a specific gas to be measured or only light absorbed by the specific gas under the control of the controller 200, and the first photodetector 130. ) And the second photodetector 140 detect only light of a wavelength band absorbed by the specific gas or light absorbed by the specific gas and provide an electric signal corresponding to the detected light amount to the controller 200. Here, the electrical signals provided from the first photodetector 130 and the second photodetector 140 may be voltage or current, but in the embodiment of the present invention, for example, the voltages V1 and V2 are provided. Explain.

In addition, the light emitted from the first light source 110 reaches the first photodetector 130 after passing through the first light path 150 and the light emitted from the second light source 120 passes through the second light path. Pass 160 to reach the second photodetector 140. Here, the light emitted from the first light source 110 does not reach the second photodetector 140, and the light emitted from the second light source 120 does not reach the first photodetector 130. The optical path 150 and the second optical path 160 are parallel to each other and are formed to be spaced apart by a predetermined distance ΔL. In addition, the first light path 150 and the second light path 160 are formed perpendicular to the moving direction of the gas.

The controller 200 controls the operation of the gas detector 100, calculates a concentration and a flow rate of a specific gas to be measured based on an electric signal (for example, a voltage) provided from the gas detector 100, thereby determining the specific gas. Calculate the emissions.

Specifically, the control unit 200 controls the driving of the first light source 110 and the second light source 120 to emit light, and then provided from the first photodetector 130 and the second photodetector 140, respectively. The concentration of the specific gas to be measured is calculated based on the voltages V1 and V2. Herein, the controller 200 may calculate concentrations corresponding to the voltages V1 and V2 using a via-lambert function.

Thereafter, the control unit 200 controls the driving of the gas disturbance unit 300 to supply the indicating gas, and at the same time resets the time (t = 0). In addition, the controller 200 samples the voltages output from the first photodetector 130 and the second photodetector 140 at predetermined time intervals, respectively, from the first detector 130 and the second detector 140. The peak values of the provided voltages V1 and V2 and the time corresponding to the peak values of the voltages are measured, and the time difference Δt between the peak values of the two voltages is obtained.

In detail, when the indicating gas reaches the first optical path 150, the controller 200 measures a first voltage peak value that is a peak value of the voltage output from the first photodetector. The first voltage peak value is a maximum voltage value obtained by sampling a voltage at a predetermined time interval. In addition, the controller 200 measures a first time point t1 which is a time point at which the first voltage peak value is measured. Here, the first time point t1 may be measured as an elapsed time from when the time point or time at which the instruction gas is supplied is reset (that is, t = 0) to the time when the peak value of the voltage is measured.

In addition, the controller 200 may include a second peak value, which is a peak value of a voltage output from the second photodetector 140 when the indicating gas reaches the second optical path 160 through the first optical path 150. The second time point t2 which is the time point of time is measured. Here, the second time point t2 may be measured as an elapsed time from when the time point or time at which the instruction gas is supplied is reset (that is, t = 0) to the time when the second peak value of the voltage is measured.

Subsequently, the controller 200 determines a separation distance ΔL between the first optical path 150 and the second optical path 160 previously input, and a time difference between the first time point t1 and the second time point t2. Δt is used to calculate the moving speed of the indicating gas.

The control unit 200 calculates the emission per hour of the specific gas to be measured using the concentration of the specific gas, the moving speed of the indicating gas, and the cross-sectional area of the exhaust pipe from which the indicating gas is discharged as described above. Here, the controller 200 may store the calculated discharge amount of the specific gas in the storage unit 600 or display it through the input / output unit 400.

In addition, when the reference discharge amount for the specific gas discharge is set in advance, when the discharge amount is larger than the reference discharge amount by comparing the calculated discharge amount with the reference discharge amount, a warning message, a warning sound or the like through the input / output unit 400. You can also output a warning light.

In FIG. 6, for example, the single control unit 200 calculates the concentration and flow rate of the specific gas to be measured based on the voltage provided from the gas detection unit 100 and calculates the discharge amount of the specific gas based on the voltage. In another embodiment of the present invention, the control unit 200 is composed of two, the first control unit controls the driving of the first light source 110 and the second light source 120, the second control unit is the first photodetector 130 And the concentration and flow rate of the specific gas based on the voltage output from the second photodetector 140. However, as described above, when the control unit 200 is composed of two, each control unit 200 may be configured to share data and control signals with each other and interoperate with each other.

The gas disturbance unit 300 may be configured as a command gas supply device, and emit a command gas based on a control signal of the controller 200. Here, the gas disturbance unit 300 may emit in the form of a pulse of a small amount of the indicator gas, in this case, the amount of the indicator gas in one release may be set differently according to the gas measurement environment.

In addition, the gas disturbance unit 300 may further include a gas guide 171 that is formed in the inlet and outlet with respect to the flow direction of the gas to guide the flow of the gas to facilitate the gas measurement. The gas guide 171 may be formed, for example, in a cylindrical shape (or pipe shape) having a longitudinal direction in the flow direction of the gas, and the discharge speed of the gas discharged from the chimney is the same inside and outside the gas guide 171. The cross section may be formed to be the same from the inlet to the outlet when cutting in a direction perpendicular to the flow direction of the gas. In addition, the gas guide 171 is not limited in material and shape, but should be formed so that no leakage occurs until gas is introduced into the inlet of the gas guide 171 and discharged to the outlet.

Alternatively, the gas disturbance unit 300 may be configured to generate vortices in the gas flow using a chopper or the like instead of being configured to inject the indicating gas as described above.

The input / output unit 400 may include an input unit and an output unit, the input unit may include a touch pad or a keypad, and the output unit may include a display element, a warning light, a speaker, and the like.

The input / output unit 400 may display a user interface for setting a condition for measuring a gas emission amount under the control of the controller 200, and provide a signal corresponding to the values set through the user's operation to the controller 200. do. For example, the input / output unit 400 may display a user interface for setting a gas emission measurement cycle, an alarm condition, an alarm method, a type of gas for which emission is to be measured, and the data corresponding to the content set by the user. May be provided to the controller 200.

The communication unit 500 may be configured as a wired or wireless interface, and converts a gas measurement value or an event signal related to gas measurement according to a predetermined communication standard based on the control of the control unit 200 and transmits the measured signal to a predetermined destination. In addition, the communication unit 500 processes a control signal or data provided from an external device according to a communication standard and provides the same to the control unit 200.

The storage unit 600 may be configured as a nonvolatile memory, and stores a program and related data executed by the control unit 200 to measure gas emissions. In addition, the storage unit 600 may store the gas emissions calculated according to the control of the controller 200 for a preset period.

FIG. 8 is a flowchart illustrating a gas emission measuring method according to an embodiment of the present invention, and is assumed to be performed by the gas emission measuring apparatus shown in FIGS. 6 and 7.

First, in order to measure the concentration of a specific gas, the controller 200 controls the driving of the first light source 110 and the second light source 120 to emit light, and then the voltage output from the first photodetector 130. Obtains the voltage V2 output from the V1 and / or the second photodetector 140 (step 810), and corresponds to the voltages V1 and / or V2 obtained using the via-Lambert function described above. The concentration is calculated (step 820).

Thereafter, the controller 200 resets the time (that is, t = 0) and controls the driving of the gas disturbance unit 300 so that the indication gas is input (step 830).

Thereafter, the control unit 200 detects a peak value (first peak value) of the voltage output from the first photodetector 130 as the indicating gas crosses the first optical path 150, and the first peak value. The time point (first time) of is measured (step 840).

In addition, the controller 200 may determine a peak value (second peak) of the voltage output from the second photodetector 140 as the indicating gas crosses the second optical path 160 through the first optical path 150. Value) and the time point (second time) of the second peak value is measured (step 850).

Subsequently, the controller 200 specifies the difference based on the difference value Δt between the first time and the second time obtained by performing the steps 840 and 850 and the separation distance ΔL between the first light path and the second light. The flow rate of the gas is calculated (step 860).

Then, the controller 200 calculates the hourly emissions of the specific gas using the concentration of the specific gas calculated in step 820, the flow rate of the specific gas calculated in step 860, and the cross-sectional area of the outlet through which the indicated gas is discharged (step 870). ).

In addition, when a specific gas to be measured and a different type of indicating gas to be measured in step 830 of FIG. 8 are applied, the relationship between the diffusion rate of the specific gas and the diffusion rate of the indicating gas after performing step 860 using a gaseous equation The process of calculating the velocity of the specific gas may be additionally performed.

Although described with reference to the embodiments above, those skilled in the art will understand that the present invention can be variously modified and changed without departing from the spirit and scope of the invention as set forth in the claims below. Could be.

100 gas detection unit 110 first light source
120: second light source 130: first photodetector
140: second photodetector 150: first optical path
160: second light path 200: control unit
300: gas disturbance unit 400: input and output unit
500: communication unit 600: storage unit

Claims (10)

A first light source emitting light having a wavelength absorbed by a specific gas to be measured among the mixed gases discharged to the outside;
A first photodetector for detecting light emitted from the first light source and detecting a first detection signal corresponding to the detected amount of light;
A second light source emitting light of a wavelength absorbed by the specific gas;
A second photodetector for detecting light emitted from the second light source and detecting a second detection signal corresponding to the detected amount of light;
A gas disturbance unit for disturbing the flow of the mixed gas to measure a flow velocity of the specific gas; And
After calculating the concentration of the specific gas based on the first detection signal provided by the first photodetector, controlling the driving of the gas disturbance unit to disturb the flow of the mixed gas and detect the second detection provided by the second photodetector. And a controller configured to calculate a flow rate of the specific gas based on the signal, and calculate a discharge rate of the specific gas based on the calculated concentration and flow rate of the specific gas.
The first optical path between the first light source and the first photodetector and the second optical path between the second light source and the second photodetector are parallel to each other at a predetermined distance, and are parallel to the flow of the mixed gas. Gas emission measurement device characterized in that.
The method of claim 1, wherein the gas disturbance unit
The gas emission measuring apparatus, characterized in that for inputting the indicating gas in accordance with the control of the controller. The apparatus of claim 1, wherein the control unit
Receiving a voltage from the first photodetector to the first detection signal, and converting the voltage into the concentration of the specific gas using a via-lambert function.
delete The apparatus of claim 1, wherein the control unit
After calculating the concentration of the specific gas, the time is initialized and the gas disturbing unit is controlled to inject the indicated gas, and the first time is the peak value of the first voltage provided from the first photodetector and the peak time of the first voltage. After detecting the first time and the second time of the peak value of the second voltage and the peak value of the second voltage provided from the second photodetector in accordance with the flow of the indicating gas, the first time and the second And measuring the flow rate of the specific gas using a difference in time and the predetermined distance. In the gas emission measurement method for measuring the emission of a specific gas of the mixed gas discharged to the outside,
Calculating a concentration of the specific gas by emitting light having a wavelength absorbed by the specific gas to the mixed gas and detecting the emitted light;
Injecting an indication gas into an exhaust pipe through which the mixed gas flows in order to disturb the flow of the mixed gas;
Calculating a flow rate of the specific gas based on a peak value of the voltage and a peak time point of the voltage detected corresponding to the flow of the indicating gas; And
And calculating a discharge amount of the specific gas based on the calculated concentration and flow rate. The method of claim 6, wherein calculating the concentration of the specific gas comprises
Emitting light of a wavelength absorbed by the specific gas to the mixed gas;
Detecting the emitted light and obtaining a voltage corresponding to the detected light amount; And
Converting the voltage to a concentration of the particular gas using a via-lambert function. The method according to claim 6,
Injecting an indication gas to disturb the flow of the mixed gas,
Gas emission measurement method comprising the step of initializing the time. The method of claim 6, wherein calculating the flow rate of the specific gas
Measuring a peak value of a first voltage provided as the indicator gas flows through a first optical path and a first time that is a peak time point of the first voltage;
Measuring a peak time of a second voltage provided as the indication gas flows through a second light path spaced apart from the first light path by a predetermined distance, and a second time that is a peak time point of the second voltage; And
And measuring the flow rate of the specific gas using the difference between the first time and the second time and the predetermined distance. The method of claim 6, wherein the gas emission measuring method is
When the indicating gas is a gas of a different type from the specific gas
After performing the calculating of the flow rate of the specific gas, deriving a relationship between the diffusion rate of the specific gas and the diffusion rate of the indicating gas, and calculating the flow rate of the specific gas using the derived relationship; Gas emission measurement method, characterized in that.

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