Exhaust gas analysis apparatus, exhaust gas analysis method, and program storage medium for exhaust gas analysis apparatus

Abstract

The present invention provides an exhaust gas analysis device, an exhaust gas analysis method, and a program storage medium for the exhaust gas analysis device. The exhaust gas analysis device (2) analyzes exhaust gas generated by fuel combustion and includes: a first analyzer (21) for measuring the concentration of a target component in the exhaust gas; a second analyzer (22) for measuring the concentration of CO2 in the exhaust gas; a storage unit (233) for storing a hydrogen-to-carbon ratio, which is the ratio of hydrogen to carbon constituting the fuel, or an input receiving unit (230) for receiving an input of the hydrogen-to-carbon ratio; a moisture concentration inference unit (235) for inferring the moisture concentration in the exhaust gas based on the measured CO2 concentration and the hydrogen-to-carbon ratio of the fuel; and a correction unit (232) for correcting the measured concentration of the target component based on the inferred moisture concentration.

Description

Technical Field

[0001] This invention relates to an exhaust gas analysis apparatus, an exhaust gas analysis method, and a program storage medium for the exhaust gas analysis apparatus. Background Technology

[0002] In the past, for example, various gas analyzers were used to measure NO in order to analyze exhaust gases emitted from vehicles such as automobiles. x The concentration of the target component is measured. It is known that the exhaust gas contains, for example, moisture produced due to fuel combustion. If a gas analyzer is used to measure NO in the exhaust gas... x The concentration of the measured component includes measurement errors caused by moisture interference. Therefore, conventionally, for example, a moisture concentration meter is used to measure the moisture concentration in exhaust gas, and the concentration of the measured component in the exhaust gas is corrected based on the measured moisture concentration (e.g., Patent Document 1).

[0003] However, for this moisture concentration meter, calibration requires preparing gases with various moisture concentrations, but it is difficult to generate the target moisture concentration gas with high precision, thus posing a calibration challenge. Furthermore, from the perspective of saving space and reducing costs, there is also a desire to avoid installing a separate moisture concentration meter.

[0004] Existing technical documents

[0005] Patent Document 1: Japanese Patent Publication No. 2014-174054 Summary of the Invention

[0006] The technical problem to be solved by the present invention

[0007] The present invention was made in view of the above-mentioned problems. The main objective of the present invention is to provide an exhaust gas analysis device that can correct the influence of moisture on the measured components in exhaust gas without using a moisture concentration meter.

[0008] Technical solutions for solving technical problems

[0009] That is, the exhaust gas analysis apparatus of the present invention is characterized in that the exhaust gas analysis apparatus analyzes the exhaust gas generated by fuel combustion, and the exhaust gas analysis apparatus comprises: a first analyzer for measuring the concentration of a target component in the exhaust gas; a second analyzer for measuring the concentration of CO2 in the exhaust gas; a storage unit for storing a hydrogen-carbon ratio as the ratio of hydrogen to carbon constituting the fuel, or an input receiving unit for receiving the input of the hydrogen-carbon ratio (i.e., at least one of the storage unit and the input receiving unit); a moisture concentration inference unit for inferring the moisture concentration in the exhaust gas based on the measured CO2 concentration and the hydrogen-carbon ratio of the fuel; and a correction unit for correcting the measured concentration of the target component based on the inferred moisture concentration.

[0010] If it is such an exhaust gas analysis device, since it has a moisture concentration estimation unit that uses the CO2 concentration in the exhaust gas and the hydrogen-to-carbon ratio of the fuel to theoretically infer the moisture concentration in the exhaust gas, it can correct the influence of moisture on the components being measured without using a moisture concentration meter to directly measure the moisture concentration.

[0011] As a way to significantly achieve the effects of the present invention, the exhaust gas analysis apparatus can be described in the following manner: the first analyzer measures the concentration of the target component by wet measurement, and the second analyzer measures the concentration of CO2 by dry measurement.

[0012] As a specific method for the moisture concentration inference unit, the moisture concentration in the exhaust gas can be inferred by multiplying the wet CO2 concentration (which is converted from a dry method measurement to a wet method measurement) by the hydrogen-to-carbon ratio, or by an equivalent calculation.

[0013] As a specific embodiment of the exhaust gas analysis device, the exhaust gas analysis device further includes a CO2 concentration conversion unit, which converts the CO2 concentration measured by the second analyzer using the dry method into a wet method measurement value based on the hydrogen-to-carbon ratio. The correction unit uses the moisture concentration inferred by the moisture concentration inference unit and the CO2 concentration converted by the CO2 concentration conversion unit to correct the concentration of the measured component.

[0014] To more accurately infer the moisture concentration in the exhaust gas, it is preferable that the moisture concentration inference unit is configured to infer the moisture concentration in the exhaust gas based on the measured CO2 concentration, the hydrogen-to-carbon ratio of the fuel, the moisture concentration in the atmosphere, the partial pressure of the CO2 component in the exhaust gas, and the partial pressure of the H2O component in the exhaust gas.

[0015] To calculate the wet CO2 concentration with higher accuracy, the CO2 concentration conversion unit converts the CO2 concentration measured by the second analyzer using the dry method into a wet measurement value based on the hydrogen-to-carbon ratio of the fuel and the partial pressure of the CO2 components in the exhaust gas.

[0016] In addition, preferably, the exhaust gas analysis device also includes a calculation unit, which calculates the partial pressures of the CO2 and H2O components of the exhaust gas based at least on the composition of the fuel and the complete combustion mode of the fuel.

[0017] As a specific method for measuring the components of the object, NO can be cited as an example. x Furthermore, a CLD detector can be cited as a specific example of the first analyzer.

[0018] Furthermore, the exhaust gas analysis method of the present invention is characterized in that the exhaust gas analysis method analyzes the exhaust gas produced by fuel combustion, measures the concentration of the target component in the exhaust gas, measures the concentration of CO2 in the exhaust gas, infers the moisture concentration in the exhaust gas based on the measured CO2 concentration and the hydrogen-carbon ratio, which is the ratio of hydrogen to carbon constituting the fuel, and corrects the measured concentration of the target component based on the inferred moisture concentration.

[0019] Furthermore, the exhaust gas analysis device program storage medium of the present invention is characterized in that the exhaust gas analysis device program storage medium stores a program for the exhaust gas analysis device, the exhaust gas analysis device analyzing exhaust gas generated by fuel combustion, comprising: a first analyzer for measuring the concentration of a target component in the exhaust gas; and a second analyzer for measuring the concentration of CO2 in the exhaust gas, the program enabling a computer to function as a storage unit, a moisture concentration inference unit, and a correction unit, the storage unit storing a hydrogen-to-carbon ratio as the ratio of hydrogen to carbon constituting the fuel, the moisture concentration inference unit inferring the moisture concentration in the exhaust gas based on the measured CO2 concentration and the hydrogen-to-carbon ratio of the fuel, and the correction unit correcting the measured concentration of the target component based on the inferred moisture concentration.

[0020] If such an exhaust gas analysis method and exhaust gas analysis device use a program storage medium, then the same effect as that obtained by the exhaust gas analysis device described above can be obtained.

[0021] Invention Effects

[0022] According to the present invention configured in this way, an exhaust gas analysis device can be provided that can correct the influence of moisture on the measured components in exhaust gas without using a moisture concentration meter. Attached Figure Description

[0023] Figure 1 This is a diagram schematically illustrating the configuration of the exhaust gas analysis system of this embodiment.

[0024] Figure 2 This is a functional block diagram illustrating the functions of an exhaust gas analysis device implemented in the same way.

[0025] Figure 3 This is an example of the hydrogen-to-carbon ratio of each fuel stored in the exhaust gas analysis device of the same embodiment.

[0026] Figure 4 This is a flowchart illustrating exhaust gas analysis using an exhaust gas analysis device with the same implementation method.

[0027] Figure 5 This is a functional block diagram illustrating the function of an exhaust gas analysis device in another embodiment.

[0028] Figure 6 This is a functional block diagram illustrating the function of an exhaust gas analysis device in another embodiment.

[0029] Figure 7 This is an example of fuel composition information stored in an exhaust gas analysis device according to another implementation.

[0030] Figure 8 This is a functional block diagram illustrating the function of an exhaust gas analysis device in another embodiment.

[0031] Explanation of reference numerals in the attached figures

[0032] 2. Exhaust gas analysis device

[0033] 21···First Analyzer

[0034] 22···Second Analyzer

[0035] 232···Revision Department

[0036] 233··· Storage Department

[0037] 235··· Moisture Concentration Inference Section Detailed Implementation

[0038] An embodiment of an exhaust gas analysis system equipped with the exhaust gas analysis apparatus of the present invention will be described below with reference to the accompanying drawings.

[0039] The exhaust gas analysis system 100 of this embodiment is used, for example, to measure the concentration of a target component in the exhaust gas emitted from the combustion of fuel (e.g., gasoline) in an internal combustion engine such as an engine.

[0040] Specifically, such as Figure 1As shown, the exhaust gas analysis system 100 measures the concentration of the target component in the exhaust gas discharged from the engine during vehicle mode driving tests (WLTP mode, JC08 mode, etc.) using a chassis testing device. More specifically, it includes: a constant volume sampling (CVS) device 1, configured to sample the entire exhaust gas and mix a dilution gas with the sampled exhaust gas to generate diluted exhaust gas, such that the flow rate of the diluted exhaust gas is constant; a sampling bag M, for sampling and containing the diluted exhaust gas; and an exhaust gas analysis device 2, for analyzing the diluted exhaust gas contained in the diluted exhaust gas sampling bag, measuring the concentration of the target component in the diluted exhaust gas, and calculating the concentration of the target component in the exhaust gas based on the measurement result.

[0041] like Figure 1 As shown, the CVS device 1 includes: a main flow channel ML through which exhaust gas discharged from the exhaust pipe 102 of the internal combustion engine 101 flows; a dilution gas flow channel DL through which dilution gas merges with the main flow channel ML and dilutes the exhaust gas; and a flow control unit 12, which is located downstream of the point where the main flow channel ML and the dilution gas flow channel DL merge, and controls the flow rate of the diluted exhaust gas obtained by dilution by the dilution gas to a constant.

[0042] like Figure 1 As shown, the flow control unit 12 is a critical flow venturi type consisting of a critical flow venturi tube (CFV) and a suction pump P. In this embodiment, one critical flow venturi tube (CFV) is provided, but multiple critical flow venturi tubes (CFV) can also be provided side by side. For example, by using a switching valve or the like, the critical flow venturi tube (CFV) through which the dilution exhaust gas flows can be changed, thereby changing the flow rate of the dilution exhaust gas.

[0043] With the CVS device 1 described above, when the total flow rate of exhaust gas and dilution gas, that is, the flow rate of dilution exhaust gas, is constant, a portion of the dilution exhaust gas is collected into the sampling bag M via the dilution exhaust gas sampling channel SL.

[0044] The diluted exhaust gas (hereinafter also referred to as sample gas) contained in the sampling bag M is supplied to the exhaust gas analysis device 2, which calculates the concentration of the measured component in the exhaust gas.

[0045] like Figure 2 As shown, the exhaust gas analysis device 2 includes: a first analyzer 21 for measuring the concentration of the target component in the sample gas supplied from the sampling bag M; a second analyzer 22 for measuring the concentration of CO2 in the same sample gas; and a calculation device 23 for correcting the concentration value of the target component measured by the first analyzer 21.

[0046] In addition, in this embodiment, the component being measured is NO. x(NO and NO2).

[0047] Specifically, the first analyzer 21 is a CLD (chemiluminescence) detector, which in this embodiment is configured to detect NO in the sample gas. x Wet measurement is performed. Specifically, a heating section (heating block) H is provided on the first inlet channel L1 of the first analyzer 21 to heat the flowing sample gas to a specified temperature, for example, above the dew point temperature.

[0048] The second analyzer 22 can be any analyzer capable of measuring CO2 concentration, such as NDIR (non-dispersive infrared absorption) detectors, FTIR (fourth-transform infrared spectroscopy) detectors, etc.

[0049] In this embodiment, the second analyzer 22 is configured to perform dry measurement of the CO2 concentration in the sample gas. Specifically, a moisture concentration adjustment unit D is provided on the second inlet channel L2, which branches off from the first inlet channel L1 and introduces the sample gas into the second analyzer 22. This moisture concentration adjustment unit D changes the temperature of the sample gas while maintaining a constant moisture concentration, reducing the moisture concentration in the sample gas to a preset concentration. Specifically, the moisture concentration adjustment unit D utilizes, for example, a dehumidifier that cools the sample gas introduced into the second analyzer 22 to below the dew point temperature and dehumidifies it.

[0050] The computing device 23 corrects the NO content of other components as the measured component. x The interference affects dedicated or general-purpose computers equipped with CPUs, memory, and AD converters. Furthermore, such as... Figure 2 As shown, the computing device 23 enables the CPU and its peripheral devices to cooperate according to the analysis program stored in the memory, thereby performing at least the functions of the sensitivity coefficient storage unit 231 and the correction unit 232.

[0051] A sensitivity coefficient storage unit 231 is formed in a designated area of ​​the memory, storing information for correcting other interfering components affecting NO. x The sensitivity coefficient of the influence. The sensitivity coefficient data, representing the sensitivity coefficient, is pre-stored in the sensitivity coefficient storage unit 231 before product shipment and before product operation.

[0052] Specifically, the sensitivity coefficient represents the influence of each interfering component on the sensitivity of the first analyzer 21; more specifically, it represents the relationship between the concentration of each interfering component and the relative error of the sensitivity of the first analyzer 21 at that concentration. In this embodiment, the interfering component is NO, which is mainly contained in the sample gas. xOther components, specifically CO2 and H2O (hereinafter also referred to as moisture). The sensitivity coefficient storage unit 231 stores the sensitivity coefficient K of the first analyzer 21 for CO2 concentration. CO2 And the sensitivity coefficient K of the first analyzer 21 for moisture concentration. H2O .

[0053] The correction unit 232 uses the concentration of each interfering component in the sample gas introduced into the first analyzer 21 and the sensitivity coefficient of the first analyzer 21 for each interfering component to correct the NO in the sample gas measured by the first analyzer 21. x Concentration. The correction unit 232 uses the CO2 concentration and moisture concentration in the sample gas introduced into the first analyzer 21, as well as the sensitivity coefficient K. CO2 K H2O The NO measured by the first analyzer 21 is corrected according to the following formula (1) or an equivalent calculation. x concentration.

[0054]

[0055] Here,

[0056] NO x_a NO before revision x Concentration (NO measured by the first analyzer 21) x Concentration value (ppm)

[0057] NO x_b : Revised NO x Concentration [ppm]

[0058] CO2: This refers to the CO2 concentration in the sample gas introduced into the first analyzer 21, measured in ppm using a wet method.

[0059] C H2O : is the moisture concentration [ppm] in the sample gas introduced into the first analyzer 21.

[0060] Therefore, in order to calculate the moisture concentration in the sample gas introduced into the first analyzer 21 without using a moisture concentration meter, the exhaust gas analysis device 2 of this embodiment... Figure 2 As shown, the computing device 23 also functions as an input receiving unit 230, a hydrogen-to-carbon ratio storage unit 233, a CO2 concentration conversion unit 234, and a moisture concentration inference unit 235.

[0061] The input receiving unit 230 receives input information related to the fuel used (e.g., fuel type, hydrogen-to-carbon ratio, etc.) and outputs it to the CO2 concentration conversion unit 234 and the moisture concentration estimation unit 235. In this embodiment, the input receiving unit 230 receives input information related to the type of fuel used. This information is input by a user using a specified input device such as a mouse or keyboard.

[0062] A hydrogen-to-carbon ratio storage unit 233 is formed in a designated area of ​​the memory, which associates and stores the hydrogen-to-carbon ratio (HCR) of the fuel used in the internal combustion engine with the type of fuel. Before product shipment and before product operation, HCR data, indicating the HCR corresponding to multiple types of fuel, is pre-stored in the HCR storage unit 233 of this embodiment. This HCR data can be stored, for example, in the form of a lookup table.

[0063] Specifically, such as Figure 3 As shown in the table, the hydrogen-to-carbon ratio data represents the ratio of the number of hydrogen atoms (H) to the number of carbon atoms (C) constituting each fuel (H / C), and the ratio of the number of water molecules (H2O) to the number of CO2 molecules produced assuming complete combustion of each fuel (F). H2O .

[0064] The CO2 concentration conversion unit 234 calculates the wet CO2 concentration, which is the CO2 concentration measured by the dry method by the second analyzer 22, into a wet measurement value. Specifically, the CO2 concentration conversion unit 234 uses the CO2 concentration measured by the dry method by the second analyzer 22 and the hydrogen-carbon ratio stored in the hydrogen-carbon ratio storage unit 233 to calculate the wet CO2 concentration by performing the following formula (2) or an equivalent calculation. In addition, here, the CO2 concentration conversion unit 234 is configured to obtain the hydrogen-carbon ratio of the fuel used from the hydrogen-carbon ratio storage unit 233 based on the information related to the fuel type received from the input receiving unit 230.

[0065]

[0066] Here,

[0067] CO 2(wet) Wet CO2 concentration [ppm]

[0068] CO 2(dry) The CO2 concentration [ppm] measured by the second analyzer 22 using the dry method.

[0069] F H2O : The hydrogen-to-carbon ratio of the fuel used.

[0070] The moisture concentration estimation unit 235 estimates the moisture concentration in the sample gas introduced into the first analyzer 21 (hereinafter, the estimated concentration will also be referred to as the estimated moisture concentration). Specifically, the moisture concentration estimation unit 235 uses the CO2 concentration measured by the second analyzer 22 and the hydrogen-carbon ratio stored in the hydrogen-carbon ratio storage unit 233 to calculate the estimated moisture concentration by performing the following formula (3) or an equivalent calculation. In addition, here, the moisture concentration estimation unit 235 is configured to obtain the hydrogen-carbon ratio of the fuel used from the hydrogen-carbon ratio storage unit 233 based on the information related to the fuel type received from the input receiving unit 230.

[0071]

[0072] Here,

[0073] C H2O(esti) Infer the moisture concentration [ppm].

[0074] CO 2(dry) The CO2 concentration [ppm] measured by the second analyzer 22 using the dry method.

[0075] F H2O : The hydrogen-to-carbon ratio of the fuel used.

[0076] Furthermore, by solving the following equation (4) which expresses the relationship between the hydrogen-to-carbon ratio of the fuel and the moisture concentration and CO2 concentration in the sample gas obtained by burning the fuel, and the following equation (5) which converts the CO2 concentration, which is a dry measurement value, into a wet measurement value based on the moisture concentration, the above equations (2) and (3) are derived.

[0077]

[0078]

[0079] Furthermore, the correction unit 232 uses the inferred moisture concentration calculated by the moisture concentration inference unit 235 and the wet CO2 concentration calculated by the CO2 concentration conversion unit 234 to correct the NO measured by the first analyzer 21. x Concentration. That is, the correction unit 232 uses the inferred moisture concentration C. H2O(esti) As the moisture concentration in equation (1), the wet CO2 concentration CO is used. 2(wet) As a CO2 concentration, the NO correction x concentration.

[0080] Next, regarding the operation of the exhaust gas analysis device 2 in this embodiment, refer to... Figure 4 The flowchart is used for illustration.

[0081] The user first inputs information related to the fuel used in the vehicle test (fuel type) (step S11). Then, the sample gas contained in the sampling bag M is analyzed using the first analyzer 21 and the second analyzer 22, and the NO content in the sample gas is measured. x The moisture concentration and CO2 concentration (dry method measurement value) are calculated (step S12). The moisture concentration estimation unit 235 calculates the estimated moisture concentration contained in the sample gas introduced into the first analyzer 21 based on the CO2 concentration (dry method measurement value) measured by the second analyzer 22 and the hydrogen-to-carbon ratio corresponding to the input fuel type. In addition, the CO2 concentration conversion unit calculates the CO2 concentration (wet method) that converts the dry method measurement value to a wet method measurement value based on the CO2 concentration (dry method measurement value) measured by the second analyzer 22 and the hydrogen-to-carbon ratio corresponding to the input fuel type (step S13). Furthermore, the correction unit 232 corrects the NO calculated by the first analyzer 21 based on the calculated estimated moisture concentration, CO2 concentration (wet method), and sensitivity coefficient. x Concentration (step S14).

[0082] The exhaust gas analysis apparatus 2 of this embodiment, configured in this way, includes a moisture concentration estimation unit 235 that theoretically estimates the moisture concentration in the exhaust gas using the CO2 concentration in the exhaust gas and the hydrogen-to-carbon ratio of the fuel. Therefore, without directly measuring the moisture concentration using a moisture concentration meter, it is possible to correct the moisture content relative to the NO measured by the CLD detector 21. x The effect of concentration.

[0083] Furthermore, the present invention is not limited to the embodiments described herein.

[0084] For example, such as Figure 5 As shown, in another embodiment, the exhaust gas analysis device 2 can also be configured such that both the first analyzer 21 and the second analyzer 22 perform wet measurement. In this case, the exhaust gas analysis device 2 may not have the function of being a CO2 concentration conversion unit 234. In this case, the moisture concentration inference unit 235 can also be configured to calculate the inferred moisture concentration by performing the following formula (6) or an equivalent calculation using the CO2 concentration measured by the second analyzer 22 and the hydrogen-carbon ratio stored in the hydrogen-carbon ratio storage unit 233.

[0085]

[0086] Here,

[0087] C H2O(esti) Infer the moisture concentration [ppm].

[0088] CO 2(wet) The CO2 concentration [ppm] measured by the second analyzer 22 using the wet method.

[0089] FH2O : The hydrogen-to-carbon ratio of the fuel used.

[0090] Furthermore, in this case, the correction unit 232 uses the inferred moisture concentration calculated by the moisture concentration inference unit 235 and the CO2 concentration measured by the second analyzer 22 using a wet method to correct the NO measured by the first analyzer 21. x concentration.

[0091] In addition, the input receiving unit 230 of the above embodiment receives input information related to the fuel type, but in another embodiment, it may be configured to receive the hydrogen-to-carbon ratio (H / C, F) of the fuel. H2O The input of relevant information. In this case, the following method can be used: if the input receiving unit 230 receives information related to the hydrogen-carbon ratio, it stores it in the hydrogen-carbon ratio storage unit 233, and the CO2 concentration conversion unit 234 and the moisture concentration inference unit 235 perform the above calculation with reference to the hydrogen-carbon ratio stored in the hydrogen-carbon ratio storage unit 233.

[0092] In the described embodiment, the first analyzer 21 is a CLD detector, but detectors using other principles, such as NDIR detectors, FID detectors, FTIR detectors, and QCL-IR detectors, can also be used.

[0093] In the described embodiment, the component being measured is NO. x However, it is not limited to this; other components such as carbon compounds such as CO, HC and THC, and sulfur compounds such as SO2 and H2S can also be used as the components to be measured.

[0094] In the described embodiment, the exhaust gas analysis system 100 samples and dilutes the entire exhaust gas, but is not limited to this. In another embodiment, a portion of the exhaust gas may also be sampled and diluted.

[0095] Furthermore, the exhaust gas analysis device 2 of the above embodiment analyzes the diluted exhaust gas obtained by diluting the exhaust gas, but is not limited to this. In another embodiment, the exhaust gas analysis device 2 may also be configured to analyze the undiluted exhaust gas itself.

[0096] In the described embodiment, the exhaust gas analysis system 100 measures the target components in the exhaust gas emitted during a test using a chassis testing device, but is not limited thereto. In another embodiment, the target components may also be measured in the exhaust gas emitted during a test using a drive testing device such as an engine testing device or a powertrain testing device.

[0097] In the described embodiment, the exhaust gas analysis system 100 measures the target components in exhaust gas discharged from internal combustion engines such as engines, but is not limited thereto. In another embodiment, the target components may also be measured in exhaust gas discharged from external combustion engines such as those in thermal power plants, factories, etc.

[0098] Alternatively, the exhaust gas analysis system 100 in another embodiment may be configured to include a gas sensor (not shown) that measures at least the H2O concentration and CO2 concentration in the atmosphere (hereinafter also referred to as test atmosphere) of the test environment (e.g., vehicle test chamber) where vehicle testing is performed. Figure 6 As shown, the exhaust gas analyzer 2 obtains information (atmospheric gas information) related to the measured H2O concentration and CO2 concentration in the test atmosphere, and takes this atmospheric gas information into account to correct the concentration of the measured component.

[0099] In this case, the computing device 23 may also function as a fuel composition storage unit 236 and a partial pressure correction coefficient calculation unit (the calculation unit mentioned in the claims) 237.

[0100] The fuel composition storage unit 236 associates and stores information related to the composition of the fuel used in the internal combustion engine (also referred to simply as composition information) with the type of fuel. Specifically, such as... Figure 7 As shown in the table, this composition information represents the quantity of each element in the chemical formula of each fuel after standardization according to the quantity of element C (here, the quantity of H element is n, and the quantity of O element is m). Fuel composition data, representing the composition of fuels corresponding to multiple types of fuels, is stored in this fuel composition storage unit 236 before product shipment and before product operation. For example, this fuel composition data can be stored in the form of a lookup table or similar table.

[0101] The partial pressure correction coefficient calculation unit 237 calculates a partial pressure correction coefficient, which is used to correct the measured values ​​of various gas concentrations measured by the analyzer or sensor according to their partial pressures (also referred to simply as partial pressure correction). In this embodiment, the partial pressure correction coefficient calculation unit 237 calculates a first partial pressure correction coefficient α and a second partial pressure correction coefficient β. The first partial pressure correction coefficient α is used to correct the partial pressure of CO2 concentration in the sample gas measured by the second analyzer 22, and the second partial pressure correction coefficient β is used to correct the partial pressure of H2O concentration in the test atmosphere measured by the moisture concentration meter.

[0102] The partial pressure correction factor is the ratio of the partial pressure of the target gas in the sample gas to the pressure of the test atmosphere (specifically, atmospheric pressure). The first partial pressure correction factor α and the second partial pressure correction factor β can be expressed by the following equations (7) and (8), respectively.

[0103] α = Partial pressure of CO2 in the sample gas / Atmospheric pressure (7)

[0104] β = Partial pressure of H2O in the sample gas / Atmospheric pressure (8)

[0105] The term "partial pressure of CO2 in the sample gas" refers to the sum of the partial pressures of CO2 originating from the test atmosphere and the partial pressures of CO2 produced through fuel combustion. The same applies to the "partial pressure of H2O in the sample gas."

[0106] Here, the partial pressure correction coefficient calculation unit 237 calculates the fuel type based at least on the information received by the input receiving unit 230, the composition information stored in the fuel composition storage unit 236, and the fuel composition considering the gaseous components in the atmosphere (let its composition be CH). n O m The complete combustion formula (9) is used to calculate the partial pressures of CO2 and H2O in the sample gas, and the correction coefficients α and β for each partial pressure are calculated.

[0107] CH n O m +(1+1 / 4n-1 / 2m)·O2+N2+Ar+H2O (air) +CO 2(air) →CO 2(comb) +1 / 2n·H2O( comb) +N2+Ar+H2O (air) +CO 2(air) (9)

[0108] Here,

[0109] CH n O m :fuel,

[0110] H2O( air ): Testing the H2O content in the atmosphere.

[0111] CO2 air ): Tests the CO2 content in the atmosphere.

[0112] CO2 comb CO2 components produced by combustion

[0113] H2O( comb ): H2O produced by combustion.

[0114] Furthermore, in this embodiment, the CO2 concentration conversion unit 234 uses the CO2 concentration measured by the second analyzer 22 by dry method and the hydrogen-carbon ratio stored in the hydrogen-carbon ratio storage unit 233, and also uses the first partial pressure correction coefficient α calculated by the partial pressure correction coefficient calculation unit 237 to perform the following formula (10) or equivalent calculation, thereby calculating the wet CO2 concentration.

[0115]

[0116] Here,

[0117] CO 2(wet) Wet CO2 concentration [ppm]

[0118] CO 2(dry) The CO2 concentration [ppm] measured by the second analyzer 22 using the dry method.

[0119] F H2O The hydrogen-to-carbon ratio of the fuel used.

[0120] α: First partial pressure correction coefficient.

[0121] In addition, in this embodiment, the moisture concentration inference unit 235 uses the CO2 concentration measured by the second analyzer 22 and the hydrogen-carbon ratio stored by the hydrogen-carbon ratio storage unit 233, as well as the measured H2O concentration in the test atmosphere, the first partial pressure correction coefficient α calculated by the partial pressure correction coefficient calculation unit 237 and the second partial pressure correction coefficient β, to perform the following formula (11) or equivalent calculation, thereby calculating the inferred moisture concentration.

[0122]

[0123] Here,

[0124] C H2O(esti) Infer the moisture concentration [ppm].

[0125] CO 2(dry) The CO2 concentration [ppm] measured by the second analyzer 22 using the dry method.

[0126] F H2O The hydrogen-to-carbon ratio of the fuel used.

[0127] H: The concentration of H2O in the atmosphere [ppm] is measured.

[0128] α: First partial voltage correction factor

[0129] β: Second partial pressure correction coefficient.

[0130] Furthermore, the correction unit 232 can use the calculated wet CO2 concentration and the inferred moisture concentration to analyze the NO in the sample gas measured by the first analyzer 21. x The concentration was corrected.

[0131] In another embodiment, when the test vehicle is equipped with an EGR (Exhaust Gas Recirculation) system, the following method can be used: the exhaust analysis device 2 obtains information related to the EGR rate from the ECU of the test vehicle, and the partial pressure correction coefficient calculation unit 237 uses the obtained information related to the EGR rate to calculate the first partial pressure correction coefficient α and the second partial pressure correction coefficient β.

[0132] Furthermore, the exhaust gas analysis device 2 of the described embodiment has the functions of a sensitivity coefficient storage unit 231, a hydrogen-to-carbon ratio storage unit 233, and a fuel composition storage unit 236, but is not limited thereto. For example... Figure 8 As shown, the exhaust gas analysis device 2 in another embodiment may not have the function of these storage units. In this case, it can be configured such that the input receiving unit 230 receives input information related to the sensitivity coefficient, hydrogen-to-carbon ratio, and fuel composition, and outputs this information to the correction unit 232, the CO2 concentration conversion unit 234, the moisture concentration inference unit 235, and the partial pressure correction coefficient calculation unit 237.

[0133] Furthermore, the present invention is not limited to the described embodiments, and various modifications can be made without departing from the spirit of the present invention.

[0134] Industrial applicability

[0135] According to the exhaust gas analysis apparatus of the present invention, the influence of moisture on the measured components in exhaust gas can be corrected without using a moisture concentration meter.

Claims

1. An exhaust gas analysis device, characterized in that, The exhaust gas analysis device analyzes the exhaust gas produced by fuel combustion. The exhaust gas analysis device includes: The first analyzer measures the concentration of the target component in the exhaust gas; The second analyzer measures the concentration of CO2 in the exhaust gas; A storage unit that stores the hydrogen-carbon ratio as the ratio of hydrogen to carbon constituting the fuel, or an input receiving unit that receives the input of the hydrogen-carbon ratio; The moisture concentration estimation unit estimates the moisture concentration in the exhaust gas based on the measured CO2 concentration and the hydrogen-to-carbon ratio of the fuel. as well as The correction unit corrects the effect of moisture on the measured concentration of the target component based on the inferred moisture concentration and a sensitivity coefficient representing the relationship between the moisture concentration and the sensitivity of the first analyzer.

2. The exhaust gas analysis device according to claim 1, characterized in that, The first analyzer measures the concentration of the component to be measured using a wet method. The second analyzer measures the CO2 concentration using a dry method.

3. The exhaust gas analysis device according to claim 2, characterized in that, The moisture concentration estimation unit estimates the moisture concentration in the exhaust gas by multiplying the wet CO2 concentration (which is converted from a dry CO2 concentration to a wet CO2 concentration) by the hydrogen-to-carbon ratio, or by equivalent calculations.

4. The exhaust gas analysis device according to claim 2 or 3, characterized in that, The exhaust gas analysis device also includes a CO2 concentration conversion unit, which converts the CO2 concentration measured by the second analyzer using the dry method into a wet method measurement value based on the hydrogen-to-carbon ratio. The correction unit uses the moisture concentration inferred by the moisture concentration inference unit and the CO2 concentration converted by the CO2 concentration conversion unit to correct the concentration of the measured component.

5. The exhaust gas analysis device according to claim 4, characterized in that, The moisture concentration estimation unit estimates the moisture concentration in the exhaust gas based on the measured CO2 concentration, the hydrogen-to-carbon ratio of the fuel, the moisture concentration in the atmosphere, the partial pressure of the CO2 component in the exhaust gas, and the partial pressure of the H2O component in the exhaust gas.

6. The exhaust gas analysis device according to claim 5, characterized in that, The CO2 concentration conversion unit converts the CO2 concentration measured by the second analyzer using the dry method into a wet method measurement value based on the hydrogen-to-carbon ratio of the fuel and the partial pressure of the CO2 components in the exhaust gas.

7. The exhaust gas analysis device according to claim 5, characterized in that, The exhaust gas analysis device also includes a calculation unit, which calculates the partial pressures of the CO2 and H2O components of the exhaust gas based at least on the composition of the fuel and the complete combustion mode of the fuel.

8. The exhaust gas analysis apparatus according to any one of claims 1 to 3, characterized in that, The component being measured is NO. x .

9. The exhaust gas analysis apparatus according to claim 8, characterized in that, The first analyzer is a CLD detector.

10. An exhaust gas analysis method, characterized in that, The exhaust gas analysis method analyzes the exhaust gas produced by fuel combustion. The concentration of the target component in the exhaust gas is measured using a first analyzer. The concentration of CO2 in the exhaust gas was measured using a second analyzer. Based on the measured CO2 concentration and the hydrogen-to-carbon ratio (the ratio of hydrogen to carbon in the fuel), the moisture concentration in the exhaust gas is inferred. Based on the inferred moisture concentration and the sensitivity coefficient representing the relationship between the moisture concentration and the sensitivity of the first analyzer, the effect of moisture on the measured concentration of the measured component is corrected.

11. A program storage medium for an exhaust gas analysis device, characterized in that, The exhaust gas analysis device uses a program storage medium to store the program for the exhaust gas analysis device. The exhaust gas analysis device analyzes exhaust gas produced by fuel combustion and includes: a first analyzer for measuring the concentration of the target component in the exhaust gas; and a second analyzer for measuring the concentration of CO2 in the exhaust gas. The exhaust gas analysis device uses a program to enable the computer to function as a storage unit, a moisture concentration inference unit, and a correction unit. The storage unit stores the hydrogen-to-carbon ratio, which is the ratio of hydrogen to carbon that constitutes the fuel. The moisture concentration estimation unit estimates the moisture concentration in the exhaust gas based on the measured CO2 concentration and the hydrogen-to-carbon ratio of the fuel. The correction unit corrects the effect of moisture on the concentration of the measured component based on the inferred moisture concentration and a sensitivity coefficient that represents the relationship between the moisture concentration and the sensitivity of the first analyzer.

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