Gas analysis device, fuel gas supply mechanism, and gas analysis method

Abstract

The present invention is a fuel gas supply mechanism for replacing a fuel gas cylinder without causing an accidental fire of hydrogen flame in a hydrogen flame ionization detection device, and comprises a first fuel gas port 51 to which a first fuel gas cylinder 10a is connected, a second fuel gas port 52 to which a second fuel gas cylinder 10b is connected, a first fuel gas flow passage 53 that connects the first fuel gas port 51 and an FID detector 4, a second fuel gas flow passage 54 that connects the second fuel gas port 52 and the FID detector 4, and a fuel gas backflow prevention mechanism 50 that prevents backflow from the first fuel gas flow passage 53 to the second fuel gas flow passage 54 or backflow from the second fuel gas flow passage 54 to the first fuel gas flow passage 53.

Description

Gas analyzer, fuel gas supply mechanism, and gas analysis method

[0001] The present invention relates to a gas analyzer, a fuel gas supply mechanism, and a gas analysis method.

[0002] Conventionally, an on-board exhaust gas analyzer that is mounted on a vehicle and measures the component concentrations of exhaust gas emitted from the vehicle is provided with a flame ionization detector (FID detector) that mixes and combusts exhaust gas and fuel gas, and measures the concentration of, for example, total hydrocarbons (THC) by detecting the ion current generated during combustion, as disclosed in Patent Document 1.

[0003] Japanese Patent Application Laid-Open No. 2006-284502

[0004] In recent years, for example, due to exhaust gas regulations in various countries (such as EURO 7 in Europe), the number of components to be measured in road driving tests has increased, and in order to measure these components, on-board exhaust gas analyzers have become larger, and vehicle loads have tended to increase. In particular, an FID detector that measures the concentration of THC requires an on-board fuel gas cylinder that supplies fuel gas for hydrogen flame combustion.

[0005] In order to reduce the impact of vehicle trunk size restrictions and increased load on exhaust gases, there is a demand for a reduction in the load capacity. In particular, with regard to FID detectors, one possible approach to reducing the load capacity is to downsize the fuel gas cylinder.

[0006] However, with a small fuel gas cylinder, the fuel gas supply time is short, and the cylinder needs to be replaced after one test, from test preparation such as warming up the exhaust gas analyzer to the actual test (road driving test). For example, when a small cylinder with a 0.7 L container (filling pressure: 9.8 MPa) is used, the fuel gas supply time is about 5 to 8 hours, and even if the shortest time from test preparation such as warming up to the actual test is assumed to be 4 hours, the cylinder basically needs to be replaced after one test.

[0007] Considering the cost of replacing fuel gas cylinders for each test, one approach is to use a small fuel gas cylinder exclusively for the main test and multiple road tests, and then use a separate, larger fuel gas cylinder for test preparations such as warm-up. However, conventional gas analyzers only have one fuel gas supply port, and if the fuel gas cylinder is replaced between test preparations such as warm-up and the main test, the supply of fuel gas to the FID detector is temporarily stopped. This causes the hydrogen flame in the FID detector to extinguish, and additional warm-up operations are required after re-ignition.

[0008] Therefore, the present invention has been made in consideration of the above-mentioned problems, and its main object is to replace a fuel gas cylinder without extinguishing the hydrogen flame in a hydrogen flame ionization detector.

[0009] That is, the gas analyzer of the present invention is a gas analyzer that analyzes hydrocarbon components contained in a sample gas, and is characterized in that it comprises a hydrogen flame ionization detector that measures the hydrocarbon components, and a fuel gas supply mechanism that supplies fuel gas to the hydrogen flame ionization detector, and the fuel gas supply mechanism comprises a first fuel gas port to which a first fuel gas cylinder is connected, a second fuel gas port to which a second fuel gas cylinder is connected, a first fuel gas flow path that connects the first fuel gas port and the hydrogen flame ionization detector, a second fuel gas flow path that connects the second fuel gas port and the hydrogen flame ionization detector, and a fuel gas backflow prevention mechanism that prevents backflow from the first fuel gas flow path to the second fuel gas flow path or from the second fuel gas flow path to the first fuel gas flow path.

[0010] In this gas analyzer, the fuel gas supply mechanism includes a first fuel gas port connected to a first fuel gas cylinder and a second fuel gas port connected to a second fuel gas cylinder, allowing fuel gas to be supplied to the flame ionization detector from two fuel gas cylinders. As a result, one fuel gas cylinder can be replaced with the other without stopping the supply of fuel gas to the flame ionization detector, i.e., without extinguishing the hydrogen flame in the flame ionization detector. In particular, the present invention includes a fuel gas backflow prevention mechanism that prevents backflow from the first fuel gas flow path to the second fuel gas flow path or from the second fuel gas flow path to the first fuel gas flow path. Therefore, when replacing a fuel gas cylinder, backflow of fuel gas through the first fuel gas flow path or the second fuel gas flow path due to a pressure difference between the first and second fuel gas cylinders can be prevented. As a result, problems caused by backflow (e.g., fuel gas leakage) can be eliminated.

[0011] In a specific embodiment of the fuel gas backflow prevention mechanism, the fuel gas backflow prevention mechanism may include a first fuel gas check valve provided in the first fuel gas flow path to prevent backflow from the second fuel gas flow path to the first fuel gas flow path, and a second fuel gas check valve provided in the second fuel gas flow path to prevent backflow from the first fuel gas flow path to the second fuel gas flow path. With this configuration, the simple configuration of providing a check valve in each fuel gas flow path can prevent backflow from the first fuel gas flow path to the second fuel gas flow path and from the second fuel gas flow path to the first fuel gas flow path.

[0012] In the present invention, while the gas analyzer is being prepared for testing, the first fuel gas cylinder is connected to the first fuel gas port, and after the test preparation is completed, the second fuel gas cylinder is connected to the second fuel gas port and the first fuel gas cylinder is removed from the first fuel gas port, and then the actual test of the sample gas using the gas analyzer is started.

[0013] Furthermore, the present invention is configured such that the fuel gas cylinder is exchanged between test preparation and actual test, and it is desirable that the first fuel gas cylinder is provided during test preparation of the gas analyzer, and the second fuel gas cylinder is provided during actual test of the sample gas using the gas analyzer.

[0014] The gas analyzer of the present invention also preferably includes a combustion supporting gas supply mechanism for supplying a combustion supporting gas to the flame ionization detector, the combustion supporting gas supply mechanism preferably including a first combustion supporting gas port connected to a first combustion supporting gas cylinder, a second combustion supporting gas port connected to a second combustion supporting gas cylinder, a first combustion supporting gas flow path connecting the first combustion supporting gas port and the flame ionization detector, a second combustion supporting gas flow path connecting the second combustion supporting gas port and the flame ionization detector, and a combustion supporting gas backflow prevention mechanism for preventing backflow from the first combustion supporting gas flow path to the second combustion supporting gas flow path or from the second combustion supporting gas flow path to the first combustion supporting gas flow path. This configuration allows the combustion supporting gas to be supplied to the flame ionization detector from two combustion supporting gas cylinders. As a result, one combustion supporting gas cylinder can be replaced with the other without stopping the supply of combustion supporting gas to the flame ionization detector, i.e., without extinguishing the hydrogen flame in the flame ionization detector. In particular, the present invention provides a combustion supporting gas backflow prevention mechanism that prevents backflow from the first combustion supporting gas flow path to the second combustion supporting gas flow path or from the second combustion supporting gas flow path to the first combustion supporting gas flow path, so that when replacing the combustion supporting gas cylinder, it is possible to prevent the combustion supporting gas from flowing back through the first combustion supporting gas flow path or the second combustion supporting gas flow path due to the pressure difference between the first combustion supporting gas cylinder and the second combustion supporting gas cylinder, thereby eliminating problems caused by backflow (such as leakage of combustion supporting gas).

[0015] As a specific embodiment of the combustion supporting gas backflow prevention mechanism, it is possible to consider that the combustion supporting gas backflow prevention mechanism comprises a first combustion supporting gas check valve provided in the first combustion supporting gas flow path to prevent backflow from the second combustion supporting gas flow path to the first combustion supporting gas flow path, and a second combustion supporting gas check valve provided in the second combustion supporting gas flow path to prevent backflow from the first combustion supporting gas flow path to the second combustion supporting gas flow path. With this configuration, it is possible to prevent backflow from the first combustion supporting gas flow path to the second combustion supporting gas flow path and from the second combustion supporting gas flow path to the first combustion supporting gas flow path with the simple configuration of providing a check valve in each combustion supporting gas flow path.

[0016] In order to make the effects of the present invention even more pronounced, it is desirable that the gas analyzer of the present invention be an on-board type that is mounted on a vehicle and analyzes hydrocarbon components contained in exhaust gas from the vehicle. With this configuration, the test can be performed by changing the fuel gas cylinder or the combustion supporting gas cylinder between the test preparation such as warming up the engine before the road test and the actual test which is the road test.

[0017] Furthermore, it is desirable that the gas analyzer according to the present invention further include a methane concentration meter that measures the concentration of methane contained in the sample gas, and a concentration calculation unit that calculates the concentration of non-methane hydrocarbons by subtracting the methane concentration from the total hydrocarbon concentration obtained by the flame ionization detector.

[0018] Furthermore, the fuel gas supply mechanism according to the present invention is a fuel gas supply mechanism that supplies fuel gas to a flame ionization detector that measures hydrocarbon components contained in a sample gas, and is characterized by comprising: a first fuel gas port to which a first fuel gas cylinder is connected; a second fuel gas port to which a second fuel gas cylinder is connected; a first fuel gas flow path that connects the first fuel gas port and the flame ionization detector; a second fuel gas flow path that connects the second fuel gas port and the flame ionization detector; and a fuel gas backflow prevention mechanism that prevents backflow from the first fuel gas flow path to the second fuel gas flow path or from the second fuel gas flow path to the first fuel gas flow path.

[0019] Furthermore, a gas analysis method according to the present invention is a gas analysis method using the gas analyzer described above, characterized in that, during preparation for testing of the gas analyzer, the fuel gas is supplied to the flame ionization detector from the first fuel gas cylinder connected to the first fuel gas port, and during actual testing of the sample gas using the gas analyzer, the fuel gas is supplied to the flame ionization detector from the second fuel gas cylinder connected to the second fuel gas port.

[0020] Furthermore, a gas analysis method according to the present invention is a gas analysis method using the gas analyzer described above, characterized in that, during preparation for testing of the gas analyzer, the fuel gas is supplied to the flame ionization detector from the first fuel gas cylinder connected to the first fuel gas port, and the supporting gas is supplied to the flame ionization detector from the supporting gas cylinder connected to the first supporting gas port, and during actual testing of the sample gas using the gas analyzer, the fuel gas is supplied to the flame ionization detector from the second fuel gas cylinder connected to the second fuel gas port, and the supporting gas is supplied to the flame ionization detector from the second supporting gas cylinder connected to the second supporting gas port.

[0021] The main test is preferably a road test. With this configuration, the fuel gas cylinder or the combustion support gas cylinder can be changed between the test preparation such as warm-up before the road test and the main test, which is the road test.

[0022] It is desirable that the fuel gas cylinder connected to the second port has a capacity of 1 L (liter) or less. With this configuration, a small fuel gas cylinder can be used, thereby reducing the load on the vehicle.

[0023] According to the present invention as described above, the fuel gas cylinder can be replaced without extinguishing the hydrogen flame in the hydrogen flame ionization detector.

[0024] 1 is an overall schematic diagram of a gas analyzer according to one embodiment of the present invention; FIG. 2 is a fluid circuit diagram connected to an FID detector of the same embodiment; FIG. 3 is an overall schematic diagram of a gas analyzer of the same embodiment, showing a state during warm-up operation; FIG. 4 is an overall schematic diagram of a gas analyzer of the same embodiment, showing a state during a road running test (main test); FIG. 5 is a flowchart showing a test procedure of the same embodiment; FIG. 6 is a fluid circuit diagram connected to an FID detector of a modified embodiment; FIG. 7 is a schematic diagram showing the configuration of a fuel gas port and a combustion supporting gas port in a modified embodiment; and FIG. 8 is an overall schematic diagram of a gas analyzer of a modified embodiment.

[0025] <One embodiment of the present invention> Hereinafter, one embodiment of a gas analyzer according to the present invention will be described with reference to the drawings. Note that in all of the drawings shown below, parts are appropriately omitted or exaggerated for clarity. Identical components are given the same reference numerals, and descriptions thereof will be omitted as appropriate.

[0026] 1. Configuration of the Gas Analyzer The gas analyzer 100 of this embodiment is mounted on a vehicle VH such as an automobile, and measures the concentrations of components in exhaust gas emitted from the vehicle VH. The on-board exhaust gas analyzer 100 can be used for real driving emissions (RDE).

[0027] This on-board exhaust gas analyzer 100 measures the component concentrations of exhaust gas sampled by an exhaust gas sampling mechanism 200, such as a sampling pipe SP, which samples all or part of the exhaust gas emitted from an exhaust pipe EH connected to the engine E of a vehicle VH.The exhaust gas sampled by the exhaust gas sampling mechanism 200 is heated or maintained at a predetermined temperature by a heating pipe HP and introduced into the on-board exhaust gas analyzer 100.

[0028] Specifically, as shown in FIG. 1, the gas analyzer 100 measures, for example, carbon monoxide (CO), carbon dioxide (CO ２ ), nitrogen oxides (NO Ｘ ), methane (CH ４The gas analyzer 100 of this embodiment is equipped with an NDIR detector 2 that uses a non-dispersive infrared (NDIR) method, a CLD detector 3 that uses a chemiluminescence (CLD) method, and an FID detector 4 that uses a flame ionization (FID) method. Note that although this embodiment has the NDIR detector 2, the CLD detector 3, and the FID detector 4, the exhaust gas detector may also have only the FID detector 4.

[0029] The NDIR detector 2 detects carbon monoxide (CO) or carbon dioxide (CO ２ The CLD detector 3 continuously measures the concentration of NO contained in the exhaust gas. Ｘ The FID detector 4 continuously measures the concentration of methane (CH ４ The on-board exhaust gas analyzer 100 continuously measures the concentration of toluene (O2) or total hydrocarbons (THC). In addition, the on-board exhaust gas analyzer 100 can be equipped with various analyzers depending on the components to be measured. For example, a PMD meter using a magnetic pressure detector (PMD) method, a Fourier transform infrared spectroscopy (FTIR) meter using a Fourier transform infrared spectroscopy (FTIR) method, a QCL-IR meter using a mid-infrared laser spectroscopy (QCL-IR) method, etc.

[0030] The analytical data obtained by these analyzers 2 to 4 is output to the information processing unit COM, which processes, records, or displays the analytical data. The above-mentioned multiple analyzers may also be provided separately.

[0031] 2, the gas analyzer 100 of this embodiment is equipped with an FID detector 4 provided in an exhaust gas flow path ML through which exhaust gas flows, a fuel gas supply mechanism 5 that supplies fuel gas to the FID detector 4 as fuel for the hydrogen flame, and a combustion supporting gas supply mechanism 6 that supplies a combustion supporting gas to the FID detector 4 to help burn the fuel gas. In this embodiment, the fuel gas is a mixed gas in which helium or nitrogen is mixed with hydrogen to give a hydrogen concentration of 40%±2% or 40%±1%, and the combustion supporting gas is air (oxygen gas).

[0032] <2. Fuel Gas Supply Mechanism 5> The fuel gas supply mechanism 5 is configured to be able to supply fuel gas from two fuel gas cylinders 10a and 10b to the FID detector 4.

[0033] Specifically, the fuel gas supply mechanism 5 has a first fuel gas port 51 to which the first fuel gas cylinder 10a is connected, a second fuel gas port 52 to which the second fuel gas cylinder is connected, a first fuel gas flow path 53 that connects the first fuel gas port 51 and the FID detector 4, and a second fuel gas flow path 54 that connects the second fuel gas port 52 and the FID detector 4.

[0034] The first fuel gas port 51 is connected to the first fuel gas cylinder 10a, for example, during test preparation such as warm-up operation. When the first fuel gas cylinder 10a is removed, the opening of the port is closed by a closing structure (not shown), so that the gas in the first fuel gas flow path 53 does not leak out to the outside.

[0035] The second fuel gas port 52 is connected to the second fuel gas cylinder 10b during the actual test, such as a road driving test, and when the second fuel gas cylinder 10b is removed, the opening of the port is closed by a closing structure (not shown), so that the gas in the second fuel gas flow path 54 does not leak out to the outside.

[0036] The first fuel gas flow path 53 is a flow path that supplies the fuel gas supplied from the first fuel gas port 51 to the FID detector 4, and in this embodiment, is connected to the upstream side of the FID detector 4 in the exhaust gas flow path ML through which the exhaust gas flows. The first fuel gas flow path 53 is provided with a first fuel gas check valve 55, which is a fuel gas backflow prevention mechanism 50 that prevents backflow from the second fuel gas flow path 54 to the first fuel gas flow path 53. The first fuel gas check valve 55 prevents fuel gas from flowing back into the first fuel gas port 51.

[0037] The exhaust gas flow path ML is provided with a flow control device ML1 such as a capillary or an orifice, and a bypass flow path BL for discharging a portion of the exhaust gas may be connected upstream of the flow control device ML1. A portion of the exhaust gas collected by the exhaust gas collection mechanism 200 is introduced into this exhaust gas flow path ML.

[0038] The second fuel gas flow path 54 is a flow path that supplies the fuel gas supplied from the second fuel gas port 52 to the FID detector 4, and in the present embodiment, is connected to the upstream side of the FID detector 4 in the exhaust gas flow path ML through which the exhaust gas flows. The second fuel gas flow path 54 is provided with a second fuel gas check valve 56, which is a fuel gas backflow prevention mechanism 50 that prevents backflow from the first fuel gas flow path 53 to the second fuel gas flow path 54. The second fuel gas check valve 56 prevents fuel gas from flowing back into the second fuel gas port 52.

[0039] In this embodiment, the first fuel gas flow path 53 and the second fuel gas flow path 54 merge downstream of the first fuel gas check valve 55 and the second fuel gas check valve 56, and this merged flow path 5A is connected to the exhaust gas flow path ML. In other words, a mixed gas of exhaust gas and fuel gas is supplied to the FID detector 4. A flow control device 5A1, such as a capillary or an orifice, is provided in this merged flow path 5A. In addition, the merged flow path 5A may be provided with an on-off valve 5A2, a pressure adjustment valve 5A3, a filter 5A4, or the like, as necessary. When the first fuel gas flow path 53 and the second fuel gas flow path 54 do not merge with each other, the above-described elements 5A1 to 5A4 can be provided in the respective flow paths 53 and 54.

[0040] <3. Combustion Supporting Gas Supply Mechanism 6> The combustion supporting gas supply mechanism 6 is configured to be able to supply combustion supporting gas from two combustion supporting gas cylinders 11a and 11b to the FID detector 4.

[0041] Specifically, the supporting gas supply mechanism 6 has a first supporting gas port 61 to which the first supporting gas cylinder 11a is connected, a second supporting gas port 62 to which the second supporting gas cylinder 11b is connected, a first supporting gas flow path 63 connecting the first supporting gas port 61 and the FID detector 4, and a second supporting gas flow path 64 connecting the second supporting gas port 62 and the FID detector 4.

[0042] The first combustion supporting gas port 61 is connected to the first combustion supporting gas cylinder 11a, for example, when preparing for a test such as warm-up operation.When the first combustion supporting gas cylinder 11a is removed, the opening of the port is closed by a closing structure (not shown), so that the combustion supporting gas in the first combustion supporting gas flow path 63 does not leak out to the outside.

[0043] The second combustion supporting gas port 62 is connected to the second combustion supporting gas cylinder 11b during the actual test, such as a road driving test, and when the second combustion supporting gas cylinder 11b is removed, the opening of the port is closed by a closing structure not shown, so that the combustion supporting gas in the second combustion supporting gas flow path 64 does not leak to the outside.

[0044] The first combustion supporting gas flow path 63 is a flow path that supplies the combustion supporting gas supplied from the first combustion supporting gas port 61 to the FID detector 4, and in this embodiment is connected to the FID detector 4. This first combustion supporting gas flow path 63 is provided with a first combustion supporting gas check valve 65, which is a combustion supporting gas backflow prevention mechanism 60 that prevents backflow from the second combustion supporting gas flow path 64 to the first combustion supporting gas flow path 63. This first combustion supporting gas check valve 65 prevents the combustion supporting gas from flowing back to the first combustion supporting gas port 61.

[0045] The second combustion supporting gas flow path 64 is a flow path that supplies the combustion supporting gas supplied from the second combustion supporting gas port 62 to the FID detector 4, and in this embodiment, is connected to the FID detector 4. This second combustion supporting gas flow path 64 is provided with a second combustion supporting gas check valve 66, which is a combustion supporting gas backflow prevention mechanism 60 that prevents backflow from the first combustion supporting gas flow path 63 to the second combustion supporting gas flow path 64. This second combustion supporting gas check valve 66 prevents the combustion supporting gas from flowing back to the second combustion supporting gas port 62.

[0046] In this embodiment, the first combustion supporting gas flow path 63 and the second combustion supporting gas flow path 64 merge downstream of the first combustion supporting gas check valve 65 and the second combustion supporting gas check valve 66, and this merged flow path 6A is connected to the FID detector 4. This merged flow path 6A is provided with a flow rate control device 6A1 such as a capillary or an orifice. In addition, the merged flow path 6A may be provided with an on-off valve 6A2 or a pressure adjustment valve 6A3, etc., as necessary. Note that when the first combustion supporting gas flow path 63 and the second combustion supporting gas flow path 64 do not merge with each other, the above-mentioned elements 6A1 to 6A3 can be provided in the respective flow paths 63, 64.

[0047] 4. Gas Analysis Method A gas analysis method using the gas analyzer 100 of this embodiment will be described with reference to FIGS.

[0048] (1) Test Preparation, Including Warm-Up Operation As shown in FIGS. 3 and 5 , in test preparation, including warm-up operation of the gas analyzer 100, the first fuel gas cylinder 10a is connected to the first fuel gas port 51, and the first supporting gas cylinder 11a is connected to the first supporting gas port 61 (step S1). This allows fuel gas to be supplied from the first fuel gas cylinder 10a to the FID detector 4, and supporting gas to be supplied from the second supporting gas cylinder 11a to the FID detector 4, thereby igniting a hydrogen flame in the FID detector 4 (step S2). Here, the test preparation, including warm-up operation of the gas analyzer 100, is a process that occurs before the road test, and the first fuel gas cylinder 10a and the first supporting gas cylinder 11a do not necessarily need to be mounted on the vehicle. Therefore, large-capacity (large) first fuel gas cylinders 10a and the first supporting gas cylinder 11a can be used.

[0049] (2) Road Running Test (Main Test) After test preparation is completed (step S3), as shown in Figures 4 and 5, the second fuel gas cylinder 10b is connected to the second fuel gas port 52, and the second combustion supporting gas cylinder 11b is connected to the second combustion supporting gas port 62 (step S4). After these connections are made, the first fuel gas cylinder 10a is removed from the first fuel gas port 51, and the first combustion supporting gas cylinder 11a is removed from the first combustion supporting gas port 61 (step S5). In other words, the supply of fuel gas to the FID detector 4 continues even during the replacement (switching) from the first fuel gas cylinder 10a to the second fuel gas cylinder 10b. The supply of combustion supporting gas to the FID detector 4 also continues during the replacement (switching) from the first combustion supporting gas cylinder 11a to the second combustion supporting gas cylinder 11b. Here, the second fuel gas cylinder 10b and the second combustion supporting gas cylinder 11b are mounted on the vehicle, and small-capacity (compact) cylinders (for example, with an internal volume of 1 L or less) can be used.

[0050] Thereafter, a road test is carried out with fuel gas supplied from the second fuel gas cylinder 10b to the FID detector 4 and supporting gas supplied from the second supporting gas cylinder 11b to the FID detector 4 (step S6).

[0051] 5. Effects of the Present Embodiment According to the gas analyzer 100 of the present embodiment configured as described above, the fuel gas supply mechanism 5 can supply fuel gas from the two fuel gas cylinders 10a, 10b to the FID detector 4. As a result, it is possible to switch from one fuel gas cylinder 10a to the other fuel gas cylinder 10b without stopping the supply of fuel gas to the FID detector 4, that is, without extinguishing the hydrogen flame in the FID detector 4.

[0052] Furthermore, according to this embodiment, combustion supporting gas can be supplied from two combustion supporting gas cylinders 11a and 11b to the FID detector 4. As a result, one combustion supporting gas cylinder 11a can be replaced with the other combustion supporting gas cylinder 11b without stopping the supply of combustion supporting gas to the FID detector 4, that is, without extinguishing the hydrogen flame in the FID detector 4.

[0053] In particular, in this embodiment, the first fuel gas flow path 53 is provided with the first fuel gas check valve 55, and the second fuel gas flow path 54 is provided with the second fuel gas check valve 56. Therefore, when replacing the fuel gas cylinders 10a, 10b, the fuel gas can be prevented from flowing back through the first fuel gas flow path 53 or the second fuel gas flow path 54 due to the pressure difference between the first fuel gas cylinder 10a and the second fuel gas cylinder 10b. As a result, problems caused by the backflow (e.g., fuel gas leakage) can be eliminated. Furthermore, the first combustion supporting gas flow path 63 is provided with the first combustion supporting gas check valve 65, and the second combustion supporting gas flow path 64 is provided with the second combustion supporting gas check valve 66. Therefore, when replacing the combustion supporting gas cylinders 11a, 11b, the fuel gas can be prevented from flowing back through the first combustion supporting gas flow path 63 or the second combustion supporting gas flow path 64 due to the pressure difference between the first combustion supporting gas cylinder 11a and the second combustion supporting gas cylinder 11b. As a result, problems caused by backflow (such as leakage of combustion supporting gas) can be eliminated.

[0054] <6. Other Embodiments> For example, although the combustion supporting gas supply mechanism 6 is configured to be able to supply combustion supporting gas from two combustion supporting gas cylinders 11 a, 11 b to the FID detector 4, the combustion supporting gas supply mechanism 6 may be configured to supply combustion supporting gas from a single combustion supporting gas cylinder to the FID detector 4 (i.e., a configuration with a single combustion supporting gas port).

[0055] Furthermore, instead of the combustion supporting gas supply mechanism 6, the fuel gas supply mechanism 5 may be configured to supply fuel gas from one fuel gas cylinder to the FID detector 4 (that is, a configuration with one fuel gas port).

[0056] In addition to the above embodiment, the fuel gas backflow prevention mechanism 50 may be configured such that an on-off valve such as a solenoid valve is provided in each of the first fuel gas flow path 53 and the second fuel gas flow path 54. By opening and closing the on-off valve provided in each of the fuel gas flow paths 53, 54, backflow from the first fuel gas flow path 53 to the second fuel gas flow path 54 and backflow from the second fuel gas flow path 54 to the first fuel gas flow path 53 can be prevented.

[0057] In addition to the above-described embodiment, the combustion supporting gas backflow prevention mechanism 60 may be provided with an on-off valve such as an electromagnetic valve in each of the first combustion supporting gas flow path 63 and the second combustion supporting gas flow path 64. By opening and closing the on-off valve provided in each of the combustion supporting gas flow paths 63, 64, it is possible to prevent backflow from the first combustion supporting gas flow path 63 to the second combustion supporting gas flow path 64 and from the second combustion supporting gas flow path 64 to the first combustion supporting gas flow path 63.

[0058] The gas analyzer 100 of the above embodiment has a built-in fuel gas supply mechanism 5 or a combustion supporting gas supply mechanism 6, but as shown in Fig. 6, the fuel gas supply mechanism 5 may be externally attached to one connection port P1 of the gas analyzer 100. Also, the combustion supporting gas supply mechanism 6 may be externally attached to one connection port P2 of the gas analyzer 100.

[0059] 7 , the gas analyzer 100 may have a configuration in which a first fuel gas attachment A1 having a first fuel gas port 51 to which the first fuel gas cylinder 10a is connected and a first fuel gas check valve 55 is externally connected to a side wall 101 of the gas analyzer 100. The gas analyzer 100 may have a configuration in which a second fuel gas attachment A2 having a second fuel gas port 52 to which the second fuel gas cylinder 10b is connected and a second fuel gas check valve 56 is externally connected to the side wall 101 of the gas analyzer 100.

[0060] 7, the gas analyzer 100 may be configured such that a first combustion supporting gas attachment B1 having a first combustion supporting gas port 61 to which the first combustion supporting gas cylinder 11a is connected and a first combustion supporting gas check valve 65 is externally connected to a side wall 101 of the gas analyzer 100. The gas analyzer 100 may be configured such that a second combustion supporting gas attachment B2 having a second combustion supporting gas port 62 to which the second combustion supporting gas cylinder 11b is connected and a second combustion supporting gas check valve 66 is externally connected to a side wall 101 of the gas analyzer 100.

[0061] Although the main test in the above embodiment is a road test, it may be a validation test, which is conducted by comparing the measurement accuracy of the on-board exhaust gas analyzer of the above embodiment with the measurement accuracy of a gas analyzer installed in a test room in a bench test using a dynamometer such as a chassis dynamometer.

[0062] Furthermore, as shown in FIG. 8 , the gas analyzer 100 may include a methane concentration meter 7 that measures the concentration of methane contained in the sample gas, separate from the FID detector 4. Examples of the methane concentration meter 7 include a QCL-IR meter using mid-infrared laser spectroscopy (QCL-IR), an IRLAM meter using infrared laser absorption modulation (IRLAM), a combination of a non-methane cutter that cuts out hydrocarbon components other than methane and an FID meter, or an FTIR meter. In this configuration, the gas analyzer 100 may further include a concentration calculation unit 8 that calculates the concentration of non-methane hydrocarbons by subtracting the methane concentration obtained by the methane concentration meter 7 from the total hydrocarbon concentration obtained by the FID detector 4. The concentration calculation unit 8 may be configured using the information processing unit COM of the above-described embodiment.

[0063] In addition, various modifications and combinations of the embodiments may be made as long as they do not go against the spirit of the present invention.

[0064] According to the present invention, the fuel gas cylinder can be replaced without extinguishing the hydrogen flame in the hydrogen flame ionization detector.

[0065] DESCRIPTION OF SYMBOLS 100: Gas analyzer 4: Hydrogen flame ionization detector 5: Fuel gas supply mechanism 10a: First fuel gas cylinder 10b: Second fuel gas cylinder 51: First fuel gas port 52: Second fuel gas port 53: First fuel gas flow path 54: Second fuel gas flow path 50: Fuel gas backflow prevention mechanism 55: First fuel gas check valve 56: Second fuel gas check valve 6: Combustion support gas supply mechanism 11a: First combustion support gas cylinder 11b: Second combustion support gas cylinder 61: First combustion support gas port 62: Second combustion support gas port 63: First combustion support gas flow path 64: Second combustion support gas flow path 60: Combustion support gas backflow prevention mechanism 65: First combustion support gas check valve 66: Second combustion support gas check valve 7: Methane concentration meter 8... Concentration calculation section

Claims

1. A gas analyzer for analyzing hydrocarbon components contained in a sample gas, A flame ionizer detector for measuring the hydrocarbon components, The system includes a fuel gas supply mechanism that supplies fuel gas to the aforementioned flame ionization detector, The aforementioned fuel gas supply mechanism is The first fuel gas port to which the first fuel gas cylinder is connected, The second fuel gas port to which the second fuel gas cylinder is connected, A first fuel gas flow path connecting the first fuel gas port and the hydrogen flame ionization detector, A second fuel gas flow path connecting the second fuel gas port and the hydrogen flame ionization detector, A gas analyzer comprising a fuel gas backflow prevention mechanism for preventing backflow from the first fuel gas passage to the second fuel gas passage, or from the second fuel gas passage to the first fuel gas passage.

2. The fuel gas backflow prevention mechanism is, A first fuel gas check valve is provided in the first fuel gas passage to prevent backflow from the second fuel gas passage to the first fuel gas passage, The gas analyzer according to claim 1, further comprising a second fuel gas check valve provided in the second fuel gas passage for preventing backflow from the first fuel gas passage to the second fuel gas passage.

3. The gas analyzer according to claim 1, wherein during the preparation of the gas analyzer for testing, the first fuel gas cylinder is connected to the first fuel gas port, and after the completion of the test preparation, the second fuel gas cylinder is connected to the second fuel gas port and the first fuel gas cylinder is removed from the first fuel gas port, and thereafter the main test of the sample gas using the gas analyzer is started.

4. During the preparation for testing of the gas analyzer, the first fuel gas cylinder is provided. The gas analyzer according to claim 1, further comprising the second fuel gas cylinder during the main test of the sample gas using the gas analyzer.

5. The system includes a combustion aid gas supply mechanism that supplies a combustion aid gas to the aforementioned hydrogen flame ionization detector, The aforementioned combustion-supporting gas supply mechanism is The first combustion gas port to which the first combustion gas cylinder is connected, The second auxiliary gas port to which the second auxiliary gas cylinder is connected, A first combustion-supporting gas flow path connecting the first combustion-supporting gas port and the hydrogen flame ionization detector, A second combustion-supporting gas flow path connecting the second combustion-supporting gas port and the hydrogen flame ionization detector, The gas analyzer according to claim 1, further comprising a combustion gas backflow prevention mechanism for preventing backflow from the first combustion gas flow path to the second combustion gas flow path, or from the second combustion gas flow path to the first combustion gas flow path.

6. The aforementioned combustion aid gas backflow prevention mechanism is, A first combustion-supporting gas check valve is provided in the first combustion-supporting gas passage to prevent backflow from the second combustion-supporting gas passage to the first combustion-supporting gas passage, The gas analyzer according to claim 5, further comprising a second combustion-supporting gas check valve provided in the second combustion-supporting gas passage for preventing backflow from the first combustion-supporting gas passage to the second combustion-supporting gas passage.

7. The gas analyzer according to claim 1, which is mounted on a vehicle and analyzes hydrocarbon components contained in the exhaust gas from the vehicle.

8. A methane concentration meter for measuring the concentration of methane contained in the sample gas, The gas analyzer according to claim 1, further comprising a concentration calculation unit that calculates the concentration of non-methane hydrocarbons by subtracting the methane concentration from the total hydrocarbon concentration obtained by the flame ionization detector.

9. A fuel gas supply mechanism that supplies fuel gas to a flame ionization detector for measuring hydrocarbon components contained in a sample gas, The first fuel gas port to which the first fuel gas cylinder is connected, The second fuel gas port to which the second fuel gas cylinder is connected, A first fuel gas flow path connecting the first fuel gas port and the hydrogen flame ionization detector, A second fuel gas flow path connecting the second fuel gas port and the hydrogen flame ionization detector, A fuel gas supply mechanism comprising a fuel gas backflow prevention mechanism for preventing backflow from the first fuel gas passage to the second fuel gas passage, or from the second fuel gas passage to the first fuel gas passage.

10. A gas analysis method using the gas analyzer described in any one of claims 1 to 8, During the preparation of the gas analyzer for testing, the fuel gas is supplied to the flame ionization detector from the first fuel gas cylinder connected to the first fuel gas port. A gas analysis method comprising supplying the fuel gas to the flame ionization detector from the second fuel gas cylinder connected to the second fuel gas port during the main test of the sample gas using the gas analyzer.

11. A gas analysis method using the gas analyzer described in claim 5, During the preparation of the gas analyzer for testing, the fuel gas is supplied to the flame ionization detector from the first fuel gas cylinder connected to the first fuel port, and the combustion gas is supplied to the flame ionization detector from the combustion gas cylinder connected to the first combustion gas port. A gas analysis method comprising supplying the fuel gas to the flame ionization detector from a second fuel gas cylinder connected to the second fuel gas port and supplying the combustion aid gas to the flame ionization detector from a second combustion aid gas cylinder connected to the second combustion aid gas port during the main test of the sample gas using the gas analyzer described above.

12. The gas analysis method according to claim 10, wherein the test is a road driving test.

13. The gas analysis method according to claim 10, wherein the volume of the fuel gas cylinder connected to the second fuel gas port is 1 L or less.