JP2015127035A - Catalyst evaluation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a catalyst evaluation device capable of accurately evaluating a catalyst to remove a harmful component in exhaust by allowing only a mixing ratio of test gas to be changed.SOLUTION: A catalyst evaluation device 1 comprises: a main flow passage 2 which allows test gas produced by mixing a plurality of component gas to flow and has a catalyst arrangement region X to arrange a catalyst therein; a plurality of component gas supply pipes 3 which are arranged upstream of the catalyst arrangement region X and connected to the main flow passage 2 to supply respective component gas thereto; and a control section 5 which changes a mixing ratio of the component gas to be included in the test gas with a total flow rate of the respective component gas supplied to the main flow passage 2 kept constant.

Description

  The present invention relates to a catalyst evaluation apparatus for evaluating a catalyst for removing harmful components contained in exhaust gas.

  When evaluating the above-described catalyst, a test gas simulating exhaust gas is used. This test gas is produced by mixing various component gases contained in the exhaust gas.

By the way, exhaust gases include those exhausted from lean engines that contain a large amount of O ₂ gas and those exhausted from rich engines that contain a lot of fuel (C _x H _y O _z ). The mixing ratio of the various component gases contained in the gas changes depending on the state of the engine. Therefore, when a catalyst is evaluated using a test gas simulating exhaust gas, it is necessary to change the mixing ratio of various component gases contained in the test gas according to the actual engine state.

  As an apparatus for evaluating a catalyst capable of changing various component concentrations contained in a test gas, there is an apparatus described in Patent Document 1, for example.

  The apparatus described in Patent Document 1 includes a main flow path in which a test gas flows and a catalyst is disposed, and a plurality of flow rate controller groups that generate test gases having different mixing ratios and flow rates of component gases. One flow rate controller group selected from among the flow rate controller groups supplies the test gas to the main flow path. And the mixing ratio of the component gas contained in the test gas which flows through the main flow path is changed by switching the flow rate controller group.

Japanese Unexamined Patent Publication No. 2013-87789

  However, in the catalyst evaluation apparatus described in Patent Document 1, the flow rate of the test gas differs for each flow rate controller group, and the pressure of the main flow path changes when the flow rate of the test gas changes. Therefore, the mixing ratio of the test gas passing through the catalyst In addition to this, the pressure applied to the catalyst also changes, resulting in a problem that the catalyst cannot be evaluated accurately by changing only the mixing ratio of the test gas.

  The present invention has been made in view of the above problems, and its main object is to provide a catalyst evaluation apparatus that can change only the mixing ratio of the test gas and perform accurate catalyst evaluation. To do.

A catalyst evaluation apparatus according to the present invention includes a main flow path provided with a catalyst arrangement region in which a test gas generated by mixing a plurality of component gases flows and a catalyst is arranged;
A total of a plurality of component gas supply pipes provided upstream of the catalyst arrangement region and connected to the main flow path for supplying each component gas, and a plurality of component gas supply flows supplied to the main flow path And a control unit that changes the mixing ratio of the component gas contained in the test gas in a state where is kept constant.

  According to the above-described configuration, since the total supply flow rate of the plurality of component gases supplied to the main flow path is made constant, the test gas is kept in the state where the flow rate of the test gas flowing through the catalyst arrangement region is kept constant. The mixing ratio of the component gases contained can be changed. Therefore, it is possible to change only the mixing ratio of the component gas contained in the test gas flowing through the catalyst arrangement region without changing the pressure in the catalyst arrangement region, and accurate catalyst evaluation can be performed.

As another specific aspect, the apparatus further includes a temperature adjustment unit that adjusts the temperature of the test gas flowing through the main flow path, and the control unit controls the temperature adjustment unit to flow through the catalyst arrangement region. The thing which changes the temperature of a test gas can be mentioned.
More specifically, the test gas whose temperature is adjusted by the temperature adjusting unit is supplied from the plurality of component gas supply pipes in a state where the sum of the supply flow rates of the plurality of component gases is constant. Things can be mentioned.

  With this configuration, the control unit can change not only the mixing ratio of the component gas contained in the test gas flowing through the catalyst arrangement region but also the temperature of the test gas flowing through the catalyst arrangement region. Variations can be increased.

  Furthermore, as another specific aspect for increasing the variation of the catalyst evaluation, a branch path provided upstream of the catalyst arrangement region and branching from the main flow path, and a flow rate of the test gas flowing through the branch path are set. A flow rate changing mechanism for changing the control gas, and the control unit controls the flow rate changing mechanism to change the flow rate of the test gas flowing in the catalyst arrangement region.

  If comprised in this way, since the control part can change the flow volume of the test gas which flows through a catalyst arrangement | positioning area | region, the catalyst evaluation which was further rich in variation can be performed, and it is in the state closer to an actual internal combustion engine. Accurate catalyst evaluation can be performed.

  In addition, as another specific aspect for increasing variations in catalyst evaluation, a discharge path that is connected downstream of the catalyst arrangement region and discharges the test gas flowing through the main flow path, and A resistance change mechanism that changes resistance is further provided, and the control unit can control the resistance change mechanism to change the pressure in the catalyst arrangement region.

  With this configuration, the control unit can change the pressure in the catalyst arrangement region, so that it is possible to perform a further variety of catalyst evaluations and accurate catalyst evaluation in a state closer to an actual internal combustion engine. It can be performed.

  According to the present invention, only the mixing ratio of the test gas can be changed, and accurate catalyst evaluation can be performed.

1 is a schematic view of a catalyst evaluation apparatus according to a first embodiment of the present invention. Schematic of the catalyst evaluation apparatus concerning 2nd Embodiment of this invention. Schematic of the catalyst evaluation apparatus concerning 3rd Embodiment of this invention.

  The catalyst evaluation apparatus of the present invention is mounted on an automobile or the like and is for evaluating the performance of a catalyst that removes harmful components in exhaust gas discharged from an engine.

<First Embodiment>
As shown in FIG. 1, the catalyst evaluation apparatus 1 according to the first embodiment of the present invention includes a catalyst arrangement region X in which a test gas generated by mixing a plurality of component gases flows and a catalyst 8 is arranged. A main flow path 2 provided, a plurality of component gas supply pipes 3 connected to the main flow path 2 for supplying each component gas, and each component gas supply pipe 3 are provided upstream of the catalyst arrangement region X. In a state in which the component gas flow rate changing mechanism 4 for changing the flow rate of the flowing component gas and the component gas flow rate changing mechanism 4 are controlled to make the total of the supply flow rates of the plurality of component gases supplied to the main flow path 2 constant. And a control unit 5 that changes the mixing ratio of the component gases contained in the test gas.

The test gas imitates exhaust gas, and is generated by mixing a plurality of component gases contained in the exhaust gas. Then, the component gases may be separated for example with _{N 2,} CO 2, poor based gas into the reaction of _{O 2,} etc., for example _CO, NO _X, SO X, into a reaction gas rich in ₃ etc. reactive NH .

  The main flow path 2 is a passage through which a base gas, a reaction gas, and a test gas generated by mixing the base gas and the reaction gas flow, and a heating unit 6, a mixing unit 7, and a catalyst are arranged. A catalyst arrangement region X is provided.

  The heating unit 6 heats the base gas flowing through the main flow path 2. And it is comprised from the heater etc. which were provided so that the main flow path 2 might be enclosed. In the present embodiment, the heating unit 6 corresponds to a temperature adjusting unit that adjusts the temperature of the test gas flowing through the main flow path 2.

  The mixing unit 7 mixes the base gas flowing through the main flow path 2 and the reaction gas to generate a test gas.

  The catalyst arrangement region X is a region where the catalyst 8 to be evaluated by this apparatus is filled. And it is provided in the main flow path 2 and downstream of the mixing part 7. The catalyst 8 removes harmful components contained in the test gas.

  The component gas supply pipe 3 is connected to the main flow path 2 to supply each component gas, and a plurality of component gas supply pipes 3 are provided according to the type of the component gas. A base gas supply pipe 10 that supplies a base gas to the main flow path 2 and a reaction gas supply pipe 11 that supplies a reaction gas to the main flow path 2 are provided.

The base gas supply pipe 10 supplies base gas to the main flow path 2. In the present embodiment, as the base gas supply pipe 10, a base gas supply pipe 10a that supplies N ₂ gas, a base gas supply pipe 10b that supplies CO ₂ gas, and a base gas supply pipe 10c that supplies O ₂ gas, Is provided.

  The downstream ends of the base gas supply pipe 10 a, the base gas supply pipe 10 b, and the base gas supply pipe 10 c merge and are connected to the first merge pipe 14. The first joining pipe 14 is connected to the main flow path 2 upstream of the heating unit 6 and introduces the base gas flowing from the base gas supply pipes 10 a, 10 b, 10 c into the main flow path 2.

The reactive gas supply pipe 11 supplies a reactive gas to the main flow path 2. In the present embodiment, as the reaction gas supply pipe 11, a reaction gas supply pipe 11 a that supplies CO gas, a reaction gas supply pipe 11 b that supplies NO _X gas, a reaction gas supply pipe 11 c that supplies SO _X gas, A reaction gas supply pipe 11d for supplying NH ₃ gas is provided.

  The downstream ends of the reactive gas supply pipe 11a, the reactive gas supply pipe 11b, the reactive gas supply pipe 11c, and the reactive gas supply pipe 11d merge and are connected to the second merging pipe 15. The second merging pipe 15 is connected to the main flow path 2 downstream of the heating section 6 and upstream of the mixing section 7, and the reaction gas flowing through the reaction gas supply pipes 11a, 11b, 11c, and 11d is supplied to the main flow path. 2 is introduced.

  The component gas flow rate changing mechanism 4 changes the flow rate of the component gas flowing through each component gas supply pipe 3, and adjusts the flow rate of the base gas flowing through each base gas supply pipe 10. And a second flow rate adjusting unit 13 for adjusting the flow rate of the reactive gas flowing through each reactive gas supply pipe 11.

The 1st flow volume adjustment part 12 adjusts the flow volume of the base gas which flows through each base gas supply piping 10, Comprising: For example, a mass flow controller can be used. The first flow rate adjusting unit 12a that adjusts the flow rate of N ₂ gas flowing through the base gas supply pipe 10a, the first flow rate adjusting unit 12b that adjusts the flow rate of CO ₂ gas flowing through the base gas supply pipe 10b, and the base gas A first flow rate adjusting unit 12c that adjusts the flow rate of the O ₂ gas flowing through the supply pipe 10c.

  The mass flow controller includes a first flow rate meter (not shown) that measures the flow rate of the base gas flowing through the base gas supply pipe 10 and a first flow rate adjustment valve (not shown) that adjusts the flow rate of the base gas flowing through the base gas supply pipe 10. Prepare.

  The first flow meter is formed by, for example, winding two pairs of heating resistance wires around a supply pipe to form a bridge circuit, and flowing two fluids through the supply pipe in a state where current is passed through the resistance wire and heated. It is possible to use a thermal type that measures the flow rate of the fluid using the temperature difference generated between the heating resistance wires.

  The first flow rate adjusting valve is externally attached to the adjustment valve main body arranged to block the base gas supply pipe 10 and the base gas supply pipe 10, and moves the adjustment valve main body according to a control signal from the control unit 5. And an adjusting valve driving unit that adjusts the opening degree in the pipe.

The second flow rate adjusting unit 13 adjusts the flow rate of the reactive gas flowing through each reactive gas supply pipe 11, and a mass flow controller can be used similarly to the first flow rate adjusting unit 12. Then, a second flow rate adjusting unit 13a that adjusts the flow rate of the CO gas flowing through the reaction gas supply pipe 11a, a second flow rate adjuster 13b for adjusting the flow rate of the NO _X gas flowing through the reaction gas supply pipe 11b, a reaction gas supply A second flow rate adjusting unit 13c that adjusts the flow rate of the SO _X gas flowing through the pipe 11c and a second flow rate adjusting unit 13d that adjusts the flow rate of the NH ₃ gas flowing through the reaction gas supply pipe 11d are provided. The mass flow controller used in the second flow rate adjusting unit 13 adjusts the flow rate of the reaction gas flowing through the reaction gas supply pipe 11 and a second flow rate meter (not shown) that measures the flow rate of the reaction gas flowing through the reaction gas supply pipe 11. A second flow rate adjusting valve (not shown).

  The control unit 5 controls the component gas flow rate changing mechanism 4 so that the sum of the supply flow rates of the plurality of component gases supplied to the main flow path 2 is constant. In this embodiment, the first flow rate adjusting unit 12 and the second flow rate adjusting unit 13 are controlled to change the mixing rate of the component gas contained in the test gas. This control unit 5 is structurally a so-called computer circuit having a CPU, an internal memory, an I / O buffer circuit, an AD converter, and the like. And, it is configured to perform information processing by operating according to a program stored in a predetermined area of the internal memory and to exert its function.

  A method in which the control unit 5 changes the mixing ratio of the component gas contained in the test gas will be described in detail.

  First, the control unit 5 receives the total value of the supply flow rates of the plurality of component gases supplied to the main flow path 2 and the ratio of each component gas at a receiving unit (not shown).

  And the control part 5 is the state which made the total value of the supply flow rate of the some component gas supplied to the main flow path 2 constant using the received total value, ie, the main flow path from the base gas supply piping 10. In the state where the total value of the supply flow rate of the base gas supplied to 2 and the supply flow rate of the reaction gas supplied from the reaction gas supply pipe 11 to the main flow path 2 is made constant, the first flow rate adjustment unit 12 (12a , 12b, 12c) and the second flow rate adjustment unit 13 (13a, 13b, 13c, 13d), and the flow rate of each component gas is changed so that the ratio of each component gas becomes the previously accepted ratio. The mixing ratio of each component gas contained in the gas is changed.

  Specifically, the control of the first flow rate adjusting unit 12 is as follows. First, the deviation between the measured value measured by each first flow meter and the set value set based on the ratio of each component gas received earlier is calculated, and proportional action, differential action, integral action, etc. are calculated based on the deviation. An arithmetic process is performed to generate a drive signal. And this drive signal is input into an adjustment valve drive part, and the 1st flow control valve is adjusted.

  The control of the second flow rate adjustment unit 13 is as follows. First, the deviation between the measured value measured by each second flow meter and the set value set based on the ratio of each component gas received earlier is calculated, and proportional action, differential action, integral action, etc. are calculated based on the deviation. An arithmetic process is performed to generate a drive signal. And this drive signal is input into an adjustment valve drive part, and the 2nd flow rate adjustment valve is adjusted.

  In the catalyst evaluation apparatus 1 according to the first embodiment configured as described above, the total of the supply flow rates of the plurality of component gases supplied to the main flow path 2 is constant, so that the test gas flowing through the catalyst arrangement region X The mixing ratio of the component gases contained in the test gas can be changed in a state where the flow rate is kept constant. Therefore, only the mixing ratio of the component gas contained in the test gas flowing through the catalyst arrangement region X region can be changed without changing the pressure in the catalyst arrangement region X, and accurate catalyst evaluation can be performed.

  Since the heating unit 6 heats only the base gas among the component gases, it is possible to prevent the reaction gas from reacting with the heating unit 6 from changing the flow rate of the test gas flowing through the catalyst arrangement region X. Therefore, the pressure change can be prevented by making the flow rate of the test gas flowing through the catalyst arrangement region X constant.

  Further, since the supply flow rate of the base gas is constant, the flow rate of the base gas flowing through the heating unit 6 that is the temperature adjusting unit can be made constant, and the temperature of the test gas flowing through the catalyst arrangement region X is made constant. be able to.

  Further, if the control unit 5 controls the heating unit 6 to change the temperature at which the base gas is heated, the temperature of the test gas generated by mixing the base gas and the reaction gas can also be changed. Therefore, the temperature of the test gas flowing through the catalyst arrangement region X can be changed, and variations in catalyst evaluation can be increased.

Second Embodiment
Next, the catalyst evaluation apparatus 1 according to the second embodiment will be described.
In addition, the same code | symbol is attached | subjected to the same part as 1st Embodiment, and description is abbreviate | omitted.

In the catalyst evaluation device 1 according to the second embodiment, as shown in FIG. 2, two reaction gas supply pipes 11 are connected to the main flow path 2, and CO gas and NO _X gas are supplied to the main flow path 2. First reaction gas supply pipes 20a and 20b for supplying each of them, and second reaction gas supply pipes 21a and 21b for supplying SO _X gas and NH ₃ gas to the main flow path 2 are provided. The downstream ends of the first reaction gas supply pipes 20 a and 20 b merge and are connected to the third merge pipe 22. Further, the downstream end portions of the second reaction gas supply pipes 21 a and 21 b are joined together and connected to the fourth joining pipe 23. The third joining pipe 22 and the fourth joining pipe 23 are connected to the main flow path 2 downstream of the heating unit 6 and upstream of the mixing unit 7.

  Also in the catalyst evaluation apparatus 1 in the second embodiment, the blending ratio of the component gas contained in the test gas can be changed while the flow rate of the test gas flowing through the catalyst arrangement region X is constant.

<Third Embodiment>
Next, the catalyst evaluation apparatus 1 according to the third embodiment will be described.
In addition, the same code | symbol is attached | subjected to the same part as 1st Embodiment and 2nd Embodiment, and description is abbreviate | omitted.

  The catalyst evaluation apparatus 1 according to the third embodiment changes the flow rate of the test gas flowing through the catalyst arrangement region X and the pressure in the catalyst arrangement region X in addition to the blending ratio and temperature of the test gas flowing through the catalyst arrangement region X. It is something that can be done.

  In addition to the first embodiment, the catalyst evaluation apparatus 1 according to the third embodiment includes a structure that changes the flow rate of the test gas that flows through the catalyst arrangement region X and a structure that changes the pressure in the catalyst arrangement region X.

  As a structure for changing the flow rate of the test gas flowing through the catalyst arrangement region X, as shown in FIG. 3, a branch passage 30 that is provided upstream of the catalyst arrangement region X and branches from the main passage 2, and a branch passage 30. And a flow rate changing mechanism 31 that changes the flow rate of the test gas flowing through the gas. As shown in FIG. 3, the structure for changing the pressure in the catalyst arrangement region X is connected to the downstream of the catalyst arrangement region X and discharges the test gas flowing in the main flow channel 2; And a resistance change mechanism 43 that changes the resistance of the discharge path 40.

  First, a structure for changing the flow rate of the test gas flowing through the catalyst arrangement region X will be described below.

  The branch path 30 is branched from the main flow path 2 downstream of the mixing unit 7 and upstream of the catalyst arrangement region X, and a part of the test gas flowing through the main flow path 2 flows.

  The flow rate change mechanism 31 includes a branch path opening / closing valve 32 that opens and closes the branch path 30, a moisture removal section 33 for removing moisture from the test gas flowing through the branch path 30, and a test gas that has passed through the moisture removal section 33. A branch flow rate adjusting valve 34 for adjusting the flow rate, and a pump 35 for causing the test gas to flow from the main flow path 2 to the branch path 30 with a differential pressure in the branch path 30 are provided.

  The branch path opening / closing valve 32 opens and closes the branch path 30 and is configured by, for example, an electromagnetic valve. Then, by opening and closing the branch path 30, the state in which the test gas flows from the main flow path 2 to the branch path 30 and the state in which the test gas does not flow from the main flow path 2 to the branch path 30 are switched.

  The moisture removing unit 33 separates and removes moisture contained in the test gas, and includes a drain separator 33a that separates moisture contained in the test gas, and a drain pot 33b that stores moisture separated by the drain separator 33a. Prepare. The test gas that has passed through the moisture removing unit 33 is in a state where moisture has been removed.

  The branching flow rate adjusting valve 34 adjusts the flow rate of the test gas flowing through the branching passage 30. For example, the branching flow rate adjusting valve 34 is configured to adjust the main body of the adjusting valve (not shown) disposed so as to block the inside of the branching passage 30. And an adjustment valve main body drive unit (not shown) that is externally attached to 30 and moves the adjustment valve main body in accordance with a control signal from the control unit 5 to adjust the opening in the road.

  Then, the control unit 5 controls the flow rate changing mechanism 31 to change the flow rate of the test gas flowing through the catalyst arrangement region X. Specifically, the control unit 5 opens a branch passage opening / closing valve 32 to flow a part of the test gas flowing through the main flow passage 2 to the branch passage 30, and sets the flow rate of the test gas flowing through the branch passage 30 to the branch passage flow rate. The adjustment valve 34 adjusts.

  Next, a structure for changing the pressure in the catalyst arrangement region X will be described below.

  The discharge path 40 is provided downstream of the catalyst arrangement region X and is connected to the main flow path 2. This discharge path 40 is provided in parallel from the middle, and branches into a plurality of branch discharge paths (first branch discharge path 41a, second branch discharge path 41b, and third branch discharge path 41c) each having a predetermined resistance.

  The branch discharge paths (the first branch discharge path 41a, the second branch discharge path 41b, and the third branch discharge path 41c) have different resistances and are configured by capillary tubes having different tube diameters and lengths. Yes. Further, the downstream ends of the first branch discharge path 41 a, the second branch discharge path 41 b and the third branch discharge path 41 c are connected to the merged discharge path 42.

  The resistance change mechanism 43 changes the resistance of the discharge path 40. In this embodiment, the resistance change mechanism 43 opens and closes the first branch discharge path 41a, the second branch discharge path 41b, and the third branch discharge path 41c. The first on-off valve 44a, the second on-off valve 44b, the third on-off valve 44c, the water removal unit 33 for removing the water of the test gas flowing through the confluence discharge path 42, and the flow rate of the test gas that has passed through the water removal unit 33 And a pump 46 for causing the test gas to flow from the main flow path 2 to the discharge path 40 with a differential pressure in the confluence discharge path 42.

  The first on-off valve 44a, the second on-off valve 44b, and the third on-off valve 44c are, for example, electromagnetic valves that are switched on and off at pulse intervals, and are not shown, but are arranged so as to close the branch discharge passage 41 A body, a valve seat that is connected to the branch discharge passage 41 and accommodates the valve body, and a drive unit that drives the valve body.

  The discharge flow rate adjusting valve 45 adjusts the flow rate of the test gas flowing through the merged discharge channel 42, and includes a regulating valve main body (not shown) arranged so as to close the merged discharge channel 42, and the combined discharge. An adjustment valve drive unit (not shown) is provided outside the path 42 and moves the adjustment valve body in accordance with a control signal from the control unit 5 to adjust the opening in the path.

  In addition, a pressure measuring instrument 50 that measures the pressure of the test gas in the main flow path 2 downstream of the mixing unit 7 and upstream of the catalyst arrangement region X is provided.

  And the control part 5 controls the resistance change mechanism 43, and changes the pressure of the catalyst arrangement | positioning area | region X. FIG. Specifically, the control unit 5 opens and closes at least one of the first on-off valve 44a, the second on-off valve 44b, or the third on-off valve 44c to change the resistance in the discharge passage 40. When the resistance in the discharge path 40 is changed, the pressure in the main flow path 2 connected to the discharge path 40 is changed, so that the pressure in the catalyst arrangement region X can be changed.

  In addition, when the control unit 5 performs control so that the opening degree of the discharge passage flow rate adjustment valve 45 is increased, the resistance of the discharge passage 40 is reduced, and thus the pressure in the catalyst arrangement region X can be reduced. On the contrary, when the opening of the discharge passage flow rate adjustment valve 45 is controlled to be small, the resistance of the discharge passage 40 increases, so that the pressure in the catalyst arrangement region X can be increased.

  Here, the opening degree of the discharge path flow rate adjustment valve 45 cannot be opened and closed instantaneously like the open / close valve 43, and is opened and closed at a lower speed than the open / close valve 43. Is controlled to change the pressure in the catalyst arrangement region X, the pressure changes steplessly.

  In the catalyst evaluation apparatus 1 according to the third embodiment configured as described above, not only the mixing ratio and temperature of the component gas contained in the test gas flowing through the catalyst arrangement region X, but also the flow rate of the test gas flowing through the catalyst arrangement region X. In addition, since the pressure in the catalyst arrangement region X can be changed, variations in catalyst evaluation can be increased.

  In addition to the first on-off valve 43a, the second on-off valve 43b, and the third on-off valve 43c, the exhaust passage flow rate adjustment valve 45 is provided as a configuration for changing the pressure in the catalyst arrangement region X. Since the high-speed pressure change by the on-off valve 43 can be superimposed on the steplessly changing pressure by the adjustment valve 45, the variation of the pressure change acting on the catalyst 8 can be further increased, for example, pulsation of the engine Etc. can be reproduced and the catalyst evaluation can be performed closer to the actual state of the internal combustion engine.

  Here, if the total value of the supply flow rates of the base gas or the reaction gas supplied to the main flow path 2 is changed, the flow rate of the test gas flowing through the catalyst arrangement region X can be changed. However, if the supply flow rate of the base gas is changed, the amount of the base gas heated by the heating unit 6 is changed, so that there is a problem that the temperature of the test gas changes with the change in the flow rate of the test gas. . On the other hand, in this embodiment, since the flow rate change mechanism 31 is separately provided, the flow rate change mechanism 31 changes the flow rate of the test gas flowing through the catalyst arrangement region X in a state where the amount of the base gas heated by the heating unit 6 is constant. Can be changed. Therefore, the temperature of the test gas can be prevented from changing with the change in the flow rate of the test gas flowing through the catalyst arrangement region X, and only the temperature of the test gas can be changed independently.

  The present invention is not limited to the above embodiment.

  In the above embodiment, the component gas is divided into the base gas and the reactive gas and supplied to the main flow path. However, the component gas may be supplied to the main flow path without being divided into the base gas and the reactive gas.

  In the above embodiment, the heating unit is used as the temperature adjustment unit, but the temperature adjustment unit is not limited to this configuration, and is provided, for example, downstream of the mixing unit and upstream of the catalyst arrangement region, A mechanism for heating or cooling the test gas flowing through the main channel may be provided separately.

  Further, in the third embodiment, the resistance change mechanism includes both the on-off valve and the discharge flow rate adjustment valve, but may include either one.

  In addition, in the third embodiment, the flow rate change mechanism changes the flow rate of the test gas flowing through the catalyst arrangement region by the branch flow rate regulating valve. An on-off valve for opening and closing the passage may be provided, and the flow rate of the test gas flowing in the catalyst arrangement region may be changed by opening and closing the on-off valve.

In addition, in the above embodiment, the base gas component concentration and the reaction gas component concentration are each changed. For example, only the base gas component concentration or only the reaction gas component concentration is changed. Also good. Specifically, when only the component concentration of the base gas is changed, a reactive gas supply in which one kind of gas selected from, for example, CO, NO _x , SO _x , and NH ₃ or a plurality of gases flows as a reactive gas. Prepare one pipe and make the flow rate of the reaction gas flowing through this pipe constant. When only the component concentration of the reaction gas is changed, a base gas supply pipe through which one gas selected from, for example, N ₂ , CO ₂ , or O ₂ or a plurality of gases flows is prepared as a base gas, The flow rate of the base gas flowing through this pipe is made constant.

Further, in the above embodiment, the catalyst evaluation device is configured so that the supply flow rate of the base gas is constant and the supply flow rate of the reaction gas is constant. However, the supply flow rate of the base gas and the supply flow rate of the reaction gas are configured. And the catalyst evaluation apparatus may be configured such that the total value of the base gas supply flow rate and the reaction gas supply flow rate is constant. Specifically, one base gas supply pipe and one reaction gas supply pipe are prepared, and the base gas flowing through the pipes reacts with the reaction so that the total flow rate of the base gas and the reaction gas flowing through these pipes is constant. Change the flow rate with the gas. At this time, as the base gas, for example, one kind of gas selected from N ₂ , CO ₂ , and O ₂ or a plurality of gases may be used, and as the reactive gas, for example, CO, NO _x , SO _x One kind of gas selected from NH ₃ or a plurality of gases may be used.

  The present invention can be variously modified without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Catalyst evaluation apparatus 2 ... Main flow path 3 ... Component gas supply piping 5 ... Control part X ... Catalyst arrangement | positioning area | region

Claims (6)

A main flow path provided with a catalyst arrangement region in which a test gas generated by mixing a plurality of component gases flows and a catalyst is arranged;
A plurality of component gas supply pipes provided upstream of the catalyst arrangement region and connected to the main flow path for supplying each component gas;
A catalyst evaluation apparatus comprising: a control unit that changes a mixing ratio of the component gas contained in the test gas in a state where the total supply flow rate of the plurality of component gases supplied to the main flow path is constant. . Further comprising a component gas flow rate change mechanism for changing the flow rate of the component gas flowing through the component gas supply pipe,
The catalyst evaluation apparatus according to claim 1, wherein the control unit controls the component gas flow rate changing mechanism. A temperature adjusting unit for adjusting the temperature of the test gas flowing through the main flow path;
3. The catalyst evaluation apparatus according to claim 1, wherein the control unit controls the temperature adjusting unit to change the temperature of the test gas flowing in the catalyst arrangement region. 4.   4. The catalyst according to claim 3, wherein the test gas whose temperature is adjusted by the temperature adjustment unit is supplied from the plurality of component gas supply pipes in a state in which the total supply flow rate of the plurality of component gases is constant. Evaluation device. A branch path provided upstream of the catalyst arrangement region and branching from the main flow path;
A flow rate change mechanism for changing the flow rate of the test gas flowing through the branch path,
5. The catalyst evaluation apparatus according to claim 1, wherein the control unit controls the flow rate change mechanism to change the flow rate of the test gas flowing through the catalyst arrangement region. A discharge path that is connected downstream of the catalyst arrangement region and discharges the test gas flowing through the main flow path;
A resistance change mechanism that changes the resistance of the discharge path;
The catalyst evaluation apparatus according to claim 1, wherein the control unit controls the resistance change mechanism to change a pressure in the catalyst arrangement region.