Technical field
[0001]
The present invention is, for example, relates to a gas analyzer and gas analyzing method for analyzing a sample gas such as exhaust gas discharged from an internal combustion engine.
BACKGROUND
[0002]
As this type of gas analyzer, using an oxidizing catalyst called non methane cutter for removing hydrocarbons other than methane from the exhaust gas, it is configured to be able to measure the methane and other hydrocarbons contained in the exhaust gas there is a thing was.
[0003]
　Resolution for separating methane and other hydrocarbons in non methane cutter by a methane transmission efficiency (that methane transmission efficiency), and a hydrocarbon other than methane such as ethane transmission efficiency (referred to ethane transmission efficiency) It is evaluated. Methane transmission efficiency is high as good, ethane transmission efficiency is low the better, as the specifically required level, such as methane transmission efficiency becomes 85% or more, and, the ethane transmission efficiency of 2% or less becomes resolution are exemplified.
[0004]
　Here, the gas analyzer described in Patent Document 1, in order to improve the resolution of non-methane cutter is configured to allow adding water to the non-methane cutter, thereby the methane takes the non methane cutter thereby improving the methane transmission efficiency by suppressing the combustion.
[0005]
　On the other hand, since the addition combustion of ethane by moisture is suppressed improved ethane transmission efficiency, in order to secure the required level of resolution of the non-methane cutter the amount of water supplied to the non-methane cutter there is a need to be adjusted.
[0006]
　However, in Patent Document 1, the moisture contained in the exhaust gas is not taken into consideration at all, since the amount of water supplied to the non-methane cutter increases or decreases when the water concentration in the exhaust gas varies according to the operating state of the engine, Nonmetan resolution of the cutter is varied.
　As a result, in the gas analyzer described in Patent Document 1, the measurement accuracy is not obtained the resolution required for the non-methane cutter may occur lowered.
CITATION
Patent Document
[0007]
Patent Document 1: Japanese Patent Publication No. 8-35950
Summary of the Invention
Problems that the Invention is to Solve
[0008]
　Accordingly, the present invention has been made to solve the problems described above, by securing the resolution required for the catalyst such as non methane cutter, to make it the sample gas can be accurately measured its principal it is an issue.
Means for Solving the Problems
[0009]
　That gas analyzer of the present invention, a sample gas line sample gas flows, is provided in the sample gas line, the analyzer for detecting the concentration of a specific component contained in the sample gas, said in the sample gas line provided upstream of the analyzer, and a catalyst that reacts with the sample gas, wherein the sample gas line provided on the upstream side of the catalyst, further comprising a water concentration adjusting unit for adjusting the water concentration of the sample gas it is an feature.
[0010]
　According to the thus configured gas analyzer, the sample gas introduced into the sample gas line as the water concentration was varied by water concentration adjusting unit provided on the upstream side of the catalyst in the sample gas sample gas line by adjusting the water concentration can be kept moisture concentration constant, it is possible to suppress the increase or decrease in the amount of water supplied to the catalyst.
　Thus, while ensuring the resolution required for the catalyst, the sample gas can be accurately measured.
[0011]
　Water content the water concentration in the sample gas line is supplied to the lower and the catalyst is insufficient, the number combustion amount of such as methane in the catalyst, it may be impossible to obtain a sufficient resolution.
　Therefore, it is preferable to provide a water supply unit for supplying water between the water concentration adjusting unit in the sample gas line and the catalyst.
　With such a configuration, the sample gas moisture concentration by water concentration adjusting unit is kept constant, by supplying a predetermined amount of water from the water supply unit, is possible to supply the desired amount of water to the catalyst can, it is possible to obtain a resolution that is required in the catalyst more reliably.
[0012]
　The water Specific embodiments of the supply unit, and the sample wherein the gas line water concentration adjusting unit and water supply line connected between said catalyst, hydrogen introduction line for introducing hydrogen into the water supply line If the oxygen introduction line for introducing oxygen into the water supply line, the structure of the water provided in the supply line is reacted with hydrogen and oxygen and a moisture generation catalyst for producing water and the like.
[0013]
　As a specific embodiment of the moisture concentration adjusting unit adjusts at least one of temperature or pressure of the sample gas, and the like which adjust the water concentration of the sample gas.
[0014]
　To easily configure moisture concentration adjusting section, it is preferable that the water concentration adjusting unit is dehumidifier to reduce the water concentration to a certain concentration.
[0015]
　If the exhaust gas which the sample gas is discharged from the internal combustion engine, because the water concentration varies according to the operating conditions of the engine, the effect of the present invention is more remarkable.
[0016]
　The gas analyzing method according to the present invention, passing a sample gas to the sample gas line, the sample gas is provided to the sample gas line is passed through a catalyst which reacts with the sample gas, the sample having passed through the catalyst a gas analysis method for detecting the analyzer the concentration of a specific component contained in the gas, the sample gas is passed through a water concentration adjusting unit prior to passing said sample gas to the catalyst, moisture in the sample gas a method characterized by adjusting the concentration.
　With such a gas analysis method, it is possible to obtain effects similar to those described above the gas analyzer.
[0017]
　In the time of measurement when the analyzer calibration sample gas, in order to equalize the resolution of the catalyst, by introducing a calibration gas for calibrating the spectrometer to the sample gas line, the calibration gas after passing through the water concentration adjusting unit, before passing through the catalyst, it is preferable to supply water to the calibration gas.
Effect of the invention
[0018]
　According to the present invention configured in this manner, while ensuring the resolution required for the catalyst such as non methane cutter, the sample gas can be accurately measured.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019]
[1] a schematic diagram showing the configuration of the gas analyzer of the present embodiment.
[2] shows an operation flow chart of the gas analyzer of the embodiment.
[Figure 3] a schematic view showing a configuration of a gas analysis device of a modified embodiment.
DESCRIPTION OF SYMBOLS
[0020]
100 ... gas analyzer
L1 ... sample gas line
10 ... analyzer
20 ... oxidizing catalyst
30 ... water concentration adjusting section
40 ... water supplying portion
41 ... a platinum catalyst
DESCRIPTION OF THE INVENTION
[0021]
　It will be described with reference to the accompanying drawings, an embodiment of the gas analyzer of the present invention below.
[0022]
　Gas analyzer 100 of the present embodiment is, for example, a gas analyzer for measuring the concentration of the component contained in the sample gas, such as exhaust gas discharged from an internal combustion engine of a vehicle, wherein the mixed gas diluted with dilution air, for example, exhaust gas constructing a gas analysis system with a set constant flow constant volume sampling device for sampling (CVS). As the exhaust gas analyzing system, may be of a dilution sampling system for concentration measurement by diluting the exhaust gas, it may be of direct sampling scheme that directly concentration measurement without dilution.
[0023]
　Specifically, in this gas analyzer 100, as shown in FIG. 1, the measurement and the sample gas line L1 which the exhaust gas flows is a sample gas, provided in the sample gas line L1 and the concentration of the measurement target component contained in the sample gas and a spectrometer 10 for.
[0024]
　Analyzer 10 is for measuring the objective component hydrocarbon (HC) is an organic compound having a FID detector using flame ionization spectroscopy (FID), where contained in the sample gas measuring the concentration of total hydrocarbons (THC).
[0025]
　Specifically, in this analyzer 10, an analysis gas line L2 to analyze gas serving hydrogen gas is supplied, a combustion support gas line L3 which air serving as combustion support gas is supplied is connected, harvested sample gas the analysis gas and burner air is mixed at a predetermined ratio is introduced into the hydrogen flame, as the concentration of hydrocarbons (HC) on the basis of the HC ion current generated is ionized by the combustion of the time it can be continuously measured It is configured.
[0026]
　Gas analyzer 100 of the present embodiment, as shown in FIG. 1, provided upstream of the analyzer 10 in the sample gas line L1, the sample gas other than methane hydrocarbons (removal target component) to remove and a oxidizing catalyst 20.
　Furthermore Here, the branch line L4 merging downstream branches from the upstream side of the oxidation catalyst 20, a switching valve V, such as a three-way valve for flowing the sample gas as an alternative to the branch line L4 or oxidation catalyst 20 It is provided.
[0027]
　This configuration it is possible to measure the concentration of total hydrocarbons (THC) by passing a sample gas in the branch line L4, to measure the concentration of methane in the sample gas by flowing the sample gas to the oxidation catalyst 20 it is possible, it is possible to calculate the concentration of non-methane hydrocarbon contained in the sample gas based on these differences (NMHC).
[0028]
　Incidentally, the oxidation catalyst 20 described above a metal catalyst so-called non-methane cutter, specifically includes a manganese (IV) dioxide and copper oxide (II), for example, used in the specified temperature range such as more than 600K It is. Where resolution of the non-methane cutter is, for example, be evaluated by the transmission efficiency of the ethane is the transmission efficiency and hydrocarbons other than methane methane, these transmission efficiency that varies according to the temperature of Metankatta, resolution also it changes according to the temperature of the non-methane cutter.
[0029]
　Here, when supplying water against non methane cutter, since hydrocarbons other than methane and methane is less likely to burn, they transmission efficiency easily transmitted through the non-methane cutter increases. At this time, increase the degree of transmission efficiency of methane is greater than increase the degree of transmittance of hydrocarbons other than methane, at a defined temperature range mentioned above, be supplied appropriate amount of water to the non-methane cutter, while maintaining a low transmission efficiency of hydrocarbons other than methane, it is possible to increase the transmission efficiency of methane. In other words, by appropriately adjusting the water amount supplied to the non-methane cutter, it is possible to increase the resolution of non-methane cutter (e.g. transmission efficiency of methane 85%, the transmission efficiency of the ethane than 2%) .
[0030]
　Thus, the gas analyzer 100 of the present embodiment is provided upstream of the oxidation catalyst 20 in the sample gas line L1 as shown in FIG. 1, further comprising a water concentration adjusting unit 30 for adjusting the water concentration of the sample gas It becomes Te.
[0031]
　The water concentration adjusting unit 30 changes the temperature of the sample gas are configured so as to maintain the water concentration in the constant, but to reduce the water concentration in the sample gas to a preset concentration. Water concentration adjusting unit 30 in this case is obtained by utilizing a dehumidifier for dehumidifying the sample gas is cooled, the dehumidifier are, for example, the compressor type with the compressor. The setting concentration can be appropriately changed in accordance with the specification.
　As the water concentration adjusting unit 30, to change the pressure of the sample gas may be configured to adjust the water concentration, and adjusts the water concentration by changing both the temperature and pressure of the sample gas it may be.
[0032]
　Further gas analyzer 100 of the present embodiment, as shown in FIG. 1, is provided with a water supply unit 40 for supplying water between the water concentration adjusting unit 30 in the sample gas line L1 and the oxidation catalyst 20.
[0033]
　The water supply unit 40 includes a water concentration adjusting unit 30 in the sample gas line L1 and the water supply line L5 connected between the oxidation catalyst 20, the hydrogen introduction line L6 for introducing hydrogen into the water supply line L5, water an oxygen introduction line L7 introducing oxygen to the supply line L5, and a moisture generation catalyst serving platinum catalyst 41 for provided water supply line L5 is reacted with hydrogen and oxygen to produce water.
[0034]
　Hydrogen introduction line L6 is a line through which a gas containing a predetermined concentration of gas or hydrogen consisting only of hydrogen, wherein is also used as analytical gas line L2 described above a part.
[0035]
　Oxygen introduction line L7 is a gas or oxygen consisting of oxygen only a line for introducing a predetermined concentration containing gas. Where the oxygen introduction line L7 is a line through which air is also used as combustion aid gas line L3 described above a part.
[0036]
　Hydrogen introduction line L6 and oxygen introduction line L7 is the regulator R, respectively are provided, by adjusting the flow rate of hydrogen and oxygen supplied to the catalyst for the moisture produced by the regulator R, the amount of water produced, i.e. the water quantity supplied to the sample gas line L1 are to be controlled to a predetermined amount. The water supply unit 40 of this embodiment provides a 1 ~ 2 vol% of water in the sample gas line L1.
[0037]
　In the case in the present embodiment for calibrating the spectrometer 10, for example, the concentration is correct to introduce calibration gas containing a known methane in the sample gas line L1. Thus, a known concentration of methane contained in the calibration gas, by comparing the measured concentration of the resulting methane with analyzer 10, it is possible to calibrate the analyzer 10 as required. As the calibration gas, the concentration may be as a gas containing a known ethane and propane.
[0038]
　Wherein the calibration gas is the amount of water contained than the exhaust gas is a sample gas is using less gas. Therefore, if unless provided water concentration adjusting unit 30, so that the amount of water supplied to the non-methane cutter at the time of analysis at the time of calibration are different. Then, different resolution of non methane cutter at the time of analysis at the time of calibration, to lead to deterioration of analysis accuracy.
　In this embodiment, by introducing the calibration gas used during calibration the sample gas line L1, the calibration gas is to pass through the water concentration adjusting unit 30.
[0039]
　Hereinafter, the analysis method using the analysis apparatus according to the present embodiment will be described with reference to the flowchart of FIG.
[0040]
　First, to introduce the calibration gas for calibrating the analyzer 10 in the sample gas line L1 (S1). Switching valve V in this case, the calibration gas are in a state flowing in the non-methane cutter.
[0041]
　Accordingly, after the water a predetermined amount from the water supply unit 40 is supplied to the calibration gas, hydrocarbons other than methane are removed the calibration gas flows through the non-methane cutter. The methane concentration in the calibration gas by analyzer 10 is measured (S2).
[0042]
　Based on this calculation result, the user can compare the measured concentration of the obtained methane by spectrometer 10, a known concentration of methane actually contained in the calibration gas to calibrate the analyzer 10 as necessary (S3) .
[0043]
　Then, introducing the exhaust gas is a sample gas to the sample gas line L1 (S4). Switching valve V in this case, the calibration gas are in a state flowing in the branch line L4.
[0044]
　Thus, the sample gas is led to the spectrometer 10 without passing through the non-methane cutter, the concentration of total hydrocarbons contained by the analyzer 10 in the sample gas is measured (S5).
[0045]
　Next, the sample gas switches the switching valve V to flow in non methane cutter (S6).
[0046]
　Accordingly, after the water a predetermined amount from the water supply unit 40 to the sample gas is supplied, the sample gas hydrocarbons other than methane flows to non methane cutter is removed. The methane concentration in the sample gas is measured by analyzer 10 (S7).
[0047]
　Then, it provided the spectrometer 10 or the spectrometer 10 (not shown) provided separately from the arithmetic processing unit, based on the difference between the concentration and the methane concentration of total hydrocarbons, non-methane hydrocarbon contained in the sample gas (NMHC) to calculate the concentration (S8).
[0048]
　According to the gas analyzer 100 according to the thus constructed present embodiment, lowering the water concentration in the sample gas to a constant concentration by dehumidifier, so to supply a predetermined amount of water in the sample gas, an internal combustion engine even the water concentration in the exhaust gas varies depending on the operating conditions, it is possible to maintain the water supplied to the oxidation catalyst 20 to a certain amount.
　This can suppress a variation in resolution of the oxidation catalyst 20, it is possible to improve the accuracy of analysis.
[0049]
　Further, by introducing a calibration gas into the sample gas line L1, since the supply a predetermined amount of water with passing water concentration adjusting unit 30, in the time of calibration of the measuring time and the analyzer 10 of the sample gas, oxidizing can be made equal to the separation ability of the catalyst 20, it is possible to improve the accuracy of analysis.
[0050]
　The present invention is not limited to the embodiment.
[0051]
　For example, as shown in FIG. 3, the branch line L4 branched from the upstream side of the non-methane cutter without merging downstream of non methane cutter, for example a second analyzer 50 for analyzing the total hydrocarbon (THC may also be connected to a total of). In this case, the analyzer 10, CH measuring the concentration of methane 4 may be a meter.
　Note that these THC meter or CH 4 meters, as well as the present embodiment, those having a FID detector.
　With such a configuration, the density measurement of total hydrocarbons S5 in the embodiment, can be performed in parallel with the density measurement of methane in S7.
[0052]
　Further, since the moisture contained in the sample gas by the water concentration adjusting unit 30 is removed, where the concentration of methane and other hydrocarbons in the sample gas changes, the or analyzer 10 which spectrometer 10 is provided it may be allowed provided the water partial pressure correction portion separately provided processing unit.
　Specific to this water partial pressure correction unit obtains the removed water amount data indicating the amount of water in the sample gas which is removed by the water concentration adjusting unit 30, the methane concentration and total hydrocarbon in accordance with the amount of water configured to correct the concentration and the like.
[0053]
　Further, as the water concentration adjusting unit 30 may be one utilizing a dehumidifier desiccant using drying agent such as mineral porous type.
[0054]
　Moreover, as the water concentration adjusting unit 30, or may be configured to introduce sample gas passes through the liquid stored in for example the tank. More specifically, for example, while keeping the liquid in the tank at a constant temperature, by bubbling liquid by the sample gas, water is saturated in the sample gas, keeping the amount of water in the sample gas constant be able to. If it is possible to control the water in the sample gas in such a structure in a desired amount, it is possible to dispense with the water supply unit 40 in the embodiment.
[0055]
　In addition, in the above embodiment, the methane concentration from the measured total hydrocarbon concentration in the sample gas was determined, may be measured total hydrocarbon concentration from the measured methane concentration.
[0056]
　Incidentally, if the water concentration in the calibration gas is very low, the calibration gas having passed through the concentration adjusting unit 30, remains lower than the set concentration of the concentration adjusting unit 30, the non-methane cutter at the time of analysis at the time of calibration difference in the amount of water supplied is caused.
　Therefore, when calibrating the analyzer 10 using a calibration gas to humidify the calibration gas, it may be flowed into the water concentration adjusting unit 30.
　Thus, the water concentration in the calibration gas from the above set concentration of water concentration adjusting unit 30, by flowing calibration gas moisture concentration adjusting unit 30, the moisture concentration of the calibration gas that has passed through the water concentration adjusting unit 30 the can be a set concentration, it is possible to reduce the difference of the amount of water supplied to the non-methane cutter at the time of analysis at the time of calibration as much as possible.
[0057]
　In addition, the analyzer 10, CO meter and the CO 2 may be obtained by using infrared absorption, such as a meter.
[0058]
　Moreover the gas analyzer 100 according to the present invention can be used as the in-vehicle unit installed in a vehicle. In the case of using as the vehicle type, since it is limited to power water concentration adjusting unit 30, or less power by increasing the set temperature of the water concentration adjusting unit 30, described above as the water concentration adjusting unit 30 desiccant type dehumidifier may be used.
　The gas analyzer 100 according to the present invention can also be used as a catalyst evaluation apparatus.
　Further, as the sample gas, not only the exhaust gas of an internal combustion engine, can be applied to various gases such as gas guide and out in a combustion engine or a chemical reaction furnace such as a boiler.
[0059]
　In addition, the present invention is not limited to the embodiments, it is needless to say various modifications are possible without departing from its spirit.
Industrial Applicability
[0060]
　By using the gas analyzer of the present invention, to ensure resolution required for the oxidation catalyst such as non methane cutter, the sample gas can be accurately measured.

The scope of the claims
[Requested item 1]
　A sample gas line sample gas flows,
　is provided in the sample gas line, the analyzer for detecting the concentration of a specific component contained in the sample gas,
　provided upstream of the analyzer in the sample gas line, the a catalyst that reacts with the sample gas,
　said sample is provided on an upstream side of the catalyst in the gas line, the gas analyzer and a water concentration adjusting unit for adjusting the water concentration of the sample gas.
[Requested item 2]
　Gas analyzer according to claim 1, further comprising a water supply unit for supplying water between the water concentration adjusting unit in the sample gas line and the catalyst.
[Requested item 3]
　The water supply unit,
　the sample and the in the gas line water concentration adjusting unit and water supply line connected between said catalyst,
　and hydrogen introduction line for introducing hydrogen into the water supply line,
　the water supply line an oxygen introduction line for introducing oxygen,
　the moisture provided in the supply line gas analyzer according to claim 2 having a water generating catalyst for generating moisture by reacting hydrogen and oxygen.
[Requested item 4]
　The water concentration adjusting unit, wherein at least one of the temperature or pressure of the sample gas by adjusting the gas analyzing apparatus according to any one of claims 1 to 3 to adjust the water concentration of the sample gas.
[Requested item 5]
　The water concentration adjusting unit, the gas analyzer according to any one of claims 1 to 4 is a dehumidifier to reduce the water concentration to a certain concentration.
[Requested item 6]
　Gas analyzer according to any one of claims 1 to 5 wherein the sample gas is exhaust gas discharged from an internal combustion engine.
[Requested item 7]
　Sample gas line flowing sample gas,
　the sample gas is provided to the sample gas line is passed through a catalyst which reacts with the sample gas,
　the concentration of a specific component contained in the sample gas passing through the catalyst spectrometer a gas analyzing method of detecting by
　the water concentration of the sample gas before the sample gas is passed through the catalyst is passed through a water concentration adjusting unit, gas analysis method for adjusting the water concentration of the sample gas.
[Requested item 8]
　By introducing a calibration gas for calibrating the spectrometer to the sample gas line,
　after the calibration gas passes through the water concentration adjusting unit, before passing through the catalyst, supplying water to the calibration gas gas analyzing method according to claim 7 wherein.
[Requested item 9]
　After humidifying the calibration gas, according to claim 7 or 8 gas analyzing method according passing the water concentration adjusting unit.