JP7026054B2 - Simulated gas generator, evaluation device and simulated gas generation method - Google Patents

Description

The present invention includes, for example, a simulated gas generator that generates simulated gas that simulates exhaust gas discharged from an internal combustion engine and supplies the simulated gas to a catalyst or the like to be evaluated, and an evaluation device including the simulated gas generator. And the method of generating simulated gas.

Exhaust gas emitted from an internal combustion engine changes the type of component gas and the concentration of each component gas every moment depending on the operating conditions.
For example, an internal combustion engine does not always burn in the vicinity of stoichiometric where oxygen and fuel burn in just proportion, and depending on the load situation, lean tendency with lean fuel and rich tendency with a lot of fuel are used properly, and it is empty. The fuel ratio is constantly changing.
Therefore, in the conventional simulated gas generator for exhaust gas, as shown in Patent Document 1, several kinds of added gases are added to the first gas in a time series so that this change can be simulated. It is possible to generate a simulated gas whose components change.

By the way, since such a simulated gas generator is required to have a responsiveness sufficient to simulate a change in the operating condition of the exhaust gas, it is necessary to improve the switching responsiveness of the added gas.
Therefore, conventionally, the case where the added gas whose flow rate is controlled by a flow rate control device or the like is added to the first gas line through which the first gas flows and the case where the added gas is discharged to an external discharge line can be switched by a valve or the like. In this way, the responsiveness of switching the added gas is improved.

However, the first gas line may be provided with a heating mechanism, or a catalyst that causes a pressure loss may be provided downstream of the first gas line. Therefore, the pressure of the first gas line fluctuates due to changes in temperature, flow rate, and the like. On the other hand, the gas flowing through the discharge line is released into the atmosphere, and the pressure of the discharge line is kept relatively constant. Therefore, the pressure between the first gas line and the discharge line may be different.

Then, for example, the back pressure of the flow rate control device changes at the moment when the flow rate of the added gas connected to the discharge line and controlled to a predetermined value by the flow rate control device is switched to the first gas line. It will fluctuate temporarily.
Then, it takes time for the flow rate control device to return the fluctuating flow rate to the predetermined value again, and as a result, there may be a problem that a desired responsiveness cannot be obtained.
This problem is common not only in the simulated gas generator for exhaust gas but also in the simulated gas generator that generates simulated gas of various other gases.

Japanese Unexamined Patent Publication No. 2013-134166

The present invention has been made in view of the above problems, and even when the state in which the added gas is added to the first gas line and the state in which the added gas is discharged to the discharge line are alternately switched. The main object is to provide a simulated gas generator capable of controlling the flow rate of the added gas added to the first gas line with good responsiveness.

That is, the simulated gas generator according to the present invention is a simulated gas generator in which an additive gas is added to the first gas to generate the simulated gas, and the simulated gas is supplied to a predetermined evaluation target, and the first gas is the simulated gas generator. The flowable first gas line, the discharge line for gas discharge, the additive gas line through which the added gas flows, the switching connection mechanism for connecting the added gas line to the first gas line or the discharge line, and the above. It is characterized by comprising a pressure control mechanism for controlling the pressure of the discharge line based on the pressure suggestion value which is a value suggesting the pressure of the first gas line.

According to such a simulated gas generator, since the pressure control mechanism for adjusting the pressure of the discharge line based on the pressure suggestion value of the first gas line is provided, the pressure control mechanism is the first gas. It can be controlled to reduce the difference between the pressure of the line and the pressure of the discharge line. Therefore, when the connection destination of the added gas line is switched from the discharge line to the first line by the switching connection mechanism, the added gas of the target flow rate is supplied to the first gas line more accurately and responsively. Can be done.

As a specific embodiment of the present invention, the pressure control mechanism includes a first sensor for detecting a pressure suggestion value of the first gas line, a pressure adjusting unit provided on the discharge line, and the first. An example includes a control circuit that controls the pressure adjusting unit based on the pressure suggestion value output from the sensor.

More specifically, the pressure control mechanism is a second sensor provided on the upstream side of the pressure adjusting unit of the discharge line, and detects a pressure suggestion value which is a value suggesting the pressure of the discharge line. A second sensor is further provided. In this case, the control circuit controls the pressure adjusting unit based on the pressure suggested value indicated by the first sensor and the pressure suggested value indicated by the second sensor.

Even if the pressure control mechanism is such that the difference between the pressure indicated by the pressure suggested value output from the first sensor and the pressure indicated by the pressure suggested value output from the second sensor becomes small. good. Alternatively, the pressure control mechanism is such that the difference between the pressure indicated by the pressure suggested value output from the first sensor and the pressure indicated by the pressure suggested value output from the second sensor becomes a constant value. There may be.

The pressure control mechanism may further include a pressure control gas line that supplies the pressure control gas to the discharge line. In such a case, since a certain amount or more of gas can always flow to the discharge line while the pressure control gas is being supplied, the pressure of the discharge line is stably controlled by the pressure control unit. can do.

The simulated gas generator includes an evaluation target installation unit arranged on the first gas line and a heating furnace for heating the first gas, and the heating furnace is located upstream of the evaluation target installation unit. It may be arranged, and the first gas line and the added gas line may be merged between the heating furnace and the evaluation target installation portion, or in the heating furnace.
In such a case, the added gas can be added to the first gas heated by the heating furnace, which is particularly advantageous when the added gas chemically reacts at a high temperature. be.

It is preferable that the first sensor is provided on the upstream side of the confluence of the first gas line and the added gas line, particularly upstream of the heating furnace. In such a case, the influence of the pressure fluctuation when switching between the case where the added gas is added to the first gas line and the case where the added gas is discharged to the discharge line can be avoided, and the influence of the pressure fluctuation can be avoided. The pressure suggestion value of the gas line can be detected more stably.

The added gas may be a plurality of types of gases independently added to the first gas line, and the addition line may be provided with the switching connection mechanism.

In the case of generating a simulated gas that simulates the exhaust gas discharged from the internal combustion engine, it is particularly required to change the composition of the simulated gas one after another with time depending on the operating conditions. Therefore, the effect of the simulated gas generator according to the present invention can be more remarkably exhibited.

An embodiment capable of achieving the same effect as the present invention is a simulated gas generator in which an additive gas is added to a first gas to generate a simulated gas, and the simulated gas is supplied to a predetermined evaluation target. Switching that connects the first gas line through which the first gas flows, the discharge line for gas discharge, the added gas line through which the added gas flows, and the added gas line to the first gas line or the discharge line so as to be switchable. A simulated gas generator characterized by comprising a connection mechanism and a pressure control mechanism for controlling the pressure of the discharge line based on the pressure suggestion value, and an analyzer for analyzing the components of the simulated gas. An evaluation device for evaluating the evaluation target provided, and the evaluation device is a catalyst, a sensor, or an evaluation device including a catalyst and a sensor, can be mentioned.

Further, the simulated gas generation method according to the present invention uses a simulated gas generator that generates simulated gas by adding an additive gas to the first gas and supplies the simulated gas to a predetermined evaluation target. The generator can switch the first gas line through which the first gas flows, the discharge line for gas discharge, the added gas line through which the added gas flows, and the added gas line to the first gas line or the discharge line. It is provided with a switching connection mechanism connected to the above and a pressure control mechanism for controlling the pressure of the discharge line, and controls the pressure of the discharge line based on the pressure suggestion value of the first gas line. It is a feature.
With such a simulated gas generation method, the same action and effect as those obtained by the above-mentioned simulated gas generator can be obtained.

According to the simulated gas generator according to the present invention, since the pressure control mechanism for adjusting the pressure of the discharge line based on the pressure of the first gas line is provided, the pressure control mechanism is the first gas. It can be controlled to reduce the difference between the pressure of the line and the pressure of the discharge line. Therefore, when the connection destination of the added gas line is switched from the discharge line to the first line by the switching connection mechanism, the added gas of the target flow rate is supplied to the first gas line more accurately and responsively. Can be done.

The schematic diagram which shows the structure of the simulated gas generator which concerns on one Embodiment of this invention. FIG. 6 is a schematic diagram showing a gas flow when a third gas is added to an evaluation target in the simulated gas generator according to the same embodiment. FIG. 6 is a schematic diagram showing a gas flow when both the third gas and the fourth gas are discharged to the evaluation target in the simulated gas generator according to the same embodiment. FIG. 6 is a schematic diagram showing a gas flow when the fourth gas is added to the evaluation target in the simulated gas generator according to the same embodiment. The schematic diagram which shows the structure of the simulated gas generator which concerns on other embodiment.

100 ... Evaluation device S ... Evaluation target installation unit 1 ... Simulated gas generator 11 ... First gas line 12 ... Discharge line 13 ... Addition gas line 14 ... Heating furnace 19 ... 1st sensor 212 ... Pressure control gas line 213 ... Valve control unit

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The simulated gas generator 1 according to the present embodiment is used by being incorporated in, for example, an evaluation device 100 for evaluating the performance of a catalyst or the like mounted on an automobile or the like.
The evaluation device 100 evaluates, for example, a catalyst for removing a predetermined component in exhaust gas discharged from an internal combustion engine, a sensor for detecting a component contained in the exhaust gas, a post-treatment system provided with a catalyst, a sensor, or the like. It targets and evaluates these performances.

As shown in FIG. 1, the evaluation device 100 includes the simulated gas generator 1 and an analyzer 2 for analyzing the components of the simulated gas.
The simulated gas generator 1 adds an additive gas to the first gas to generate a simulated gas that reproduces, for example, an exhaust gas discharged from an internal combustion engine, and supplies the simulated gas to the catalyst or the like to be evaluated. It is a thing.

As shown in FIG. 1, the simulated gas generator 1 includes an evaluation target installation unit S that accommodates or connects the evaluation target, a first gas line 11 that supplies simulated gas to the evaluation target installation unit S, and a gas. It is possible to switch between the discharge line 12 for discharging the gas to the outside, the added gas line 13 through which the added gas added to the first gas line 11 flows, and the added gas line 13 to the first line 11 or the discharge line 12. The switching connection mechanism 14 connected to the above, the heating furnace 15 for adjusting the temperature of the gas flowing through the first gas line 11, the mixer 16 for mixing the gas flowing through the first gas line 11, and the pressure of the discharge line. It is provided with a pressure control mechanism 21 for controlling.

The evaluation target installation unit S is, for example, a cell that houses a three-way catalyst that removes hydrocarbons, carbon monoxide, nitrogen oxides, and the like in the exhaust gas of an internal combustion engine.

In the case of exhaust gas, for example, the first gas line 11 is the one through which the first gas, which is the base of the simulated gas such as nitrogen and water, flows.
The first gas line 11 includes a first flow rate control device MFC1 such as a mass flow controller for flowing the first gas at a predetermined flow rate, and a water addition line 111 for adding water. ..

The discharge line 12 discharges the simulated gas that has passed through the evaluation target installation unit S to the outside, and discharges the added gas to the outside without passing through the evaluation target installation unit S. The discharge line 12 may be provided with, for example, a buffer tank BT that stabilizes the pressure.
The added gas flowing through the added gas line 13 changes the composition of the simulated gas, and is, for example, rich gas, lean gas, or the like.

The heating furnace 15 is arranged as close as possible to the catalyst or the like to be evaluated so that the temperature of the simulated gas supplied to the evaluation target installation unit S can be controlled more accurately. Specifically, it is arranged immediately before the mixer 16.
The added gas line 13 merges with the first gas line 11 between the heating furnace 15 and the mixer 16, for example.

When the simulated gas generator 1 generates, for example, a gas that simulates an exhaust gas, it contains carbon monoxide, a hydrocarbon, nitrogen monoxide, and the like, which are components constituting the exhaust gas, in addition to the added gas line 13. A second gas line 17 for adding the second gas may be further provided.
In the present embodiment, the second gas line 17 includes a second flow rate control device MFC2 such as a mass flow controller that controls the flow rate of the second gas, and the first gas is provided between the heating furnace 15 and the mixer 16. It joins line 11.

Here, the added gas line 13 is a third gas line 13a through which a rich gas, which is a third gas containing a hydrocarbon or the like, flows, and a fourth gas line through which a lean gas, which is a fourth gas containing oxygen or the like, flows, for example. It is provided with 13b.

The third gas line 13a includes, for example, a third gas flow rate control device MFC3 such as a mass flow controller that controls the flow rate of rich gas, and a third gas flow rate such as a capillary that suppresses fluctuations in the flow rate of gas flowing through the third gas line 13a. It includes a resistor 13a1, a third gas addition line 13a2 for adding rich gas to the first gas line 11, and a third gas discharge line 13a3 for discharging rich gas to the discharge line 12.

Similarly, the fourth gas line 13b includes, for example, a fourth flow rate control device MFC4 such as a mass flow controller that controls the flow rate of lean gas, and a fourth such as a capillary that suppresses the flow rate of gas flowing through the fourth gas line 13b. It includes a gas flow rate resistance 13b1, a fourth gas addition line 13b2 for adding lean gas to the first gas line 11, and a fourth gas discharge line 13b3 for discharging lean gas to the discharge line 12.

The switching connection mechanism 14 switches between the third gas switching connection mechanism 141 for switching between the third gas addition line 13a2 and the third gas discharge line 13a3, and the fourth gas addition line 13b2 and the fourth gas discharge line 13b3. It is equipped with a fourth gas switching connection mechanism 142.

The third gas switching connection mechanism 141 includes, for example, a third gas addition valve 141A such as an injector and a third gas discharge valve 141B.
The third gas addition valve 141A is provided on the third gas addition line 13a2.
The third gas discharge valve 141B is provided on the third gas discharge line 13a3.

The fourth gas switching connection mechanism 142 includes, for example, a fourth gas addition valve 142A such as an injector and a fourth gas discharge valve 142B.
The fourth gas addition valve 142A is provided on the fourth gas addition line 13b2.
The fourth gas discharge valve 142B is provided on the fourth gas discharge line 13b3.

Further, the switching connection mechanism 14 includes a third gas switching control unit 141C and a fourth gas switching control unit 142C. In each of these switching control units 141C and 142C, the control circuit 18 fulfills its function.
The control circuit 18 includes, for example, a CPU, an internal memory, an I / O buffer circuit, an AD converter, and the like.
Then, the CPU and peripheral devices cooperate according to the control program stored in the predetermined area of the internal memory, so that the control circuit 18 serves as the third gas switching control unit 141C and the fourth gas switching control unit 142C, respectively. Demonstrate function.

The third gas switching control unit 141C transmits an on-off signal to the third gas addition valve 141A and the third gas discharge valve 141B, and the rich gas flowing through the third gas line 13a is generated by the third gas addition line 13a2. Alternatively, the gas is allowed to flow to either one of the third gas discharge lines 13a3.
For example, when the third gas addition valve 141A provided in the third gas addition line 13a2 is open, the third gas discharge valve 141B provided in the third gas discharge line 13a3 is closed. Be controlled.

The fourth gas switching control unit 142C transmits an on-off signal to the fourth gas addition valve 142A and the fourth gas discharge valve 142B, and the lean gas flowing through the fourth gas line 13b is the fourth gas addition line 13b2. Alternatively, the gas is allowed to flow to either one of the fourth gas discharge lines 13b3.
For example, when the fourth gas addition valve 142A provided in the fourth gas addition line 13b2 is open, the fourth gas discharge valve 142B provided in the fourth gas discharge line 13b3 is closed. Be controlled.

The pressure control mechanism 21 includes a first sensor 19 for detecting the pressure suggestion value of the first gas line 11 and a second sensor 20 for detecting the pressure suggestion value of the discharge line 12.
The first sensor 19 detects the pressure suggestion value of the first gas line 11 at the confluence of the first gas line 11 and the added gas line 13.
The confluence portion includes not only the confluence point of the first gas line 11 and the addition gas line 13, but also the first gas line 11 or the addition gas line 13 before and after the confluence point.
The pressure suggestion value has a correlation with the pressure. It is a value that can be converted into pressure by performing a predetermined operation on this pressure suggestion value.
For example, the temperature of the gas or the like can also be used as this pressure suggestion value.
In the present embodiment, the pressure value itself obtained from the pressure sensor is used as the pressure suggestion value.

The first sensor 19 is, for example, a pressure sensor provided immediately before the heating furnace 15 on the first gas line 11.
The second sensor 20 is provided in the discharge line 12, and is, for example, a pressure sensor.
The first sensor 19 plays a role in, for example, the third sensor 22 which is a pressure sensor provided near the confluence of the added gas line and the first gas line on the added gas line 13. You may try to do it.
When the temperature is used as the pressure suggestion value, the first sensor 19, the second sensor 20, and the third sensor 22 may be temperature sensors.

Further, the pressure control mechanism 21 includes a pressure control valve 211 which is a pressure control unit provided in the discharge line 12, a pressure control gas line 212 for adding a pressure control gas to the discharge line 12, and the above. It is provided with a valve control unit 213 that controls the pressure control valve 211.
The pressure adjusting unit adjusts the pressure of the discharge line 12 by controlling the flow rate, for example, a butterfly valve, a mass flow controller, an electropneumatic regulator that controls air pressure steplessly in proportion to an electric signal, or an electropneumatic regulator. It may have a valve structure such as a proportional control valve, or may be a motor, a pump, or the like.

The control circuit 18 is responsible for the function of the valve control unit 213.
Specifically, the valve control unit 213 compares the pressure of the first gas line 11 output from the first sensor 19 with the pressure of the discharge line 12 output from the second sensor 20. The pressure of the discharge line 12 with respect to the pressure control valve 211, for example, the pressure of the discharge line 12 with respect to the pressure of the first gas line 11 as close as possible to the pressure control valve 211. It issues a command signal.

The pressure control gas line 212 supplies, for example, a pressure control gas containing nitrogen or the like to the discharge line 12.
This pressure adjusting gas is constantly flowing to the discharge line 12 from, for example, a cylinder (not shown) or the like (via a mass flow controller or the like). This is so that the pressure control valve 211 can exert its pressure control function.

Next, the operation of the simulated gas generator 1 having such a configuration will be described with reference to the drawings. In the simulated gas generator 1 according to the present embodiment, the first gas, the second gas, the rich gas, and the lean gas flowing through the first gas line 11 are subjected to the mass flow controllers MFC1, MFC2, MFC3, and the mass flow controllers MFC3 provided in the respective gas lines. The MFC4 is used to control the flow rate to the required flow rate.

Then, when the composition of the simulated gas to be generated is desired to include, for example, rich gas, the third gas switching control unit 141C opens the third gas addition valve 141A and opens the third gas discharge valve 141B. Control to close. In this way, as shown in FIG. 2, the flow path is switched so that the third gas is added to the first gas line 11.

From this state, if the composition of the simulated gas is subsequently desired to be a composition in a stoichiometric state containing neither rich gas nor lean gas, the third gas switching control unit 141C closes the third gas addition valve 141A. , The third gas discharge valve 141B is controlled to be opened. Further, the fourth gas switching control unit 142C controls to close the fourth gas addition valve 142A and open the fourth gas discharge valve 142B. In this way, as shown in FIG. 3, the flow path is switched so that both the third gas and the fourth gas flow to the discharge line 12.

Further, subsequently, when the composition of the simulated gas is desired to include, for example, lean gas, the fourth gas addition valve 142A is opened by the fourth gas switching control unit 142C, and the fourth gas discharge valve is opened. Control 142B to close. In this way, as shown in FIG. 4, the flow path is switched so that the fourth gas is added to the first gas line 11. When evaluating the evaluation target by the evaluation device 100, for example, it is necessary to generate simulated gas so that these rich, stoichiometric, and lean regions appear one after another, so that the above-mentioned switching operation is performed. For example, it is repeated a plurality of times at a timing of 5 Hz or less.

In this embodiment, the case where either the rich gas or the lean gas is added has been described, but both the rich gas and the lean gas may be added to the first gas.

At this time, the valve control unit 213 compares the pressure of the first gas line 11 output from the first sensor 19 with the pressure of the discharge line 12 output from the second sensor 20. Then, the valve control unit 213 issues a command signal to the pressure control valve 211 so that the pressure of the discharge line 12 is within a predetermined range of the pressure of the first gas line 11, that is, the discharge line 12 The opening degree of the pressure control valve 211 is feedback-controlled so that the pressure of the pressure control valve 211 is as close as possible to the pressure of the first gas line 11.

According to the simulated gas generator 1 configured in this way, the pressure of the discharge line 12 is controlled by the valve control unit 213 so as to be as close as possible to the pressure of the first gas line 11. The pressure of the discharge line 12 can be set to a value close to or the same as the pressure of the first gas line 11. That is, the difference between the pressure of the discharge line 12 and the pressure of the first gas line 11 can be reduced.
As a result, when the connection destinations of the third gas line 13a and the fourth gas line 13b are switched from the discharge line 12 to the first gas line 11, the flow control devices MFC3 and MFC4 set the connection destinations to predetermined values, respectively. It is possible to suppress fluctuations in the controlled flow rates of the third gas and the fourth gas.
Therefore, when the composition of the simulated gas is changed from moment to moment in time series, for example, between the rich region, the stoichiometric region, and the lean region, the rich gas or the lean gas is added to the first gas line 11 and discharged. Even if switching between the line 12 and the line 12 one after another, the rich gas or lean gas at the target flow rate can be added to the first gas line 11 with good responsiveness.

Since the added gas line 13 includes the third gas flow rate resistance 13a1 and the fourth gas flow rate resistance 13b1, the case where the third gas and the fourth gas are added to the first line 11 and the case where the gas is discharged are discharged. It is possible to further suppress the fluctuation of the flow rate of the third gas or the fourth gas flowing through the added gas line 13 when switching between the case of discharging to the line 12 and the case of discharging to the line 12.

Further, even when the pressure of the first gas line 11 changes due to a change in the temperature of the heating furnace, replacement of an evaluation target such as a catalyst, or the like in the evaluation device 100, the discharge line 12 Since the pressure can be changed according to the pressure of the first gas line 11, it is also effective when performing evaluation by changing the temperature conditions one after another or when performing evaluation by exchanging evaluation targets one after another. be.

Further, since the first sensor 19 measures the pressure suggestion value of the first gas line 11 immediately before the heating furnace 15, the pressure suggestion value is measured by the third sensor 22 provided on the added gas line 13. Is less susceptible to pressure fluctuations when the connection destination of the added gas line 13 is switched between the first gas line 11 and the discharge line 12 as compared with the case of measuring. Therefore, the pressure of the first gas line 11 can be stably detected.

<Other embodiments>
The present invention is not limited to the above embodiment.
For example, in the above embodiment, the case of generating a simulated gas that reproduces the exhaust gas of an internal combustion engine has been exemplified, but the present invention is not limited to this, and various types of gas such as a gas generated from a battery that uses a chemical reaction can be used. It can be used when it is generated.
The simulated gas is a kind of mixed gas in which a plurality of types of gases are mixed.

The evaluation target is not limited to the three-way catalyst, and other catalysts may be used. As described above, the evaluation target is not limited to the catalyst, and for example, various types such as an A / F sensor and an O ₂ sensor that detect components in the exhaust gas. It may be a sensor, or it may be a post-processing system in which these catalysts and sensors are combined.

The evaluation device 100 of the above-described embodiment supplies only the simulated gas to the evaluation target, but the evaluation device 100 is not limited to this. In another embodiment, a mixed gas of the simulated gas and the actual gas simulated by the simulated gas may be supplied to the evaluation target, and only the actual gas is supplied to the evaluation target. You may.

If the relationship between the pressure suggestion value of the first gas line 11 and the control value of the pressure adjusting unit is stored in advance, the pressure control mechanism 21 does not necessarily have to include the second sensor.

In the embodiment, the second gas line 17 and the added gas line 13 are assumed to join the first gas line 11 on the downstream side of the heating furnace, but the second gas line 17 or the added gas line 13 may be used. It may be merged with the first gas line 11 on the upstream side of the heating furnace. Further, the second gas line 17 or the added gas line 13 may be merged with the first gas line 11 in the heating furnace.

In the embodiment, two types of gases, the third gas and the fourth gas, are added to the first gas in a switchable manner. For example, one type or three or more types of gases are added to the first gas. It may be added to the gas in a switchable manner.

In the embodiment, the valve control unit 213 is controlled so that the difference between the pressure indicated by the pressure suggested value of the discharge line 12 and the pressure indicated by the pressure suggested value of the first gas line 11 is as small as possible. It is also possible to suppress the fluctuation of the difference between the pressure indicated by the pressure suggested value of the discharge line 12 and the pressure indicated by the pressure suggested value of the first gas line 11 so that the pressure difference becomes a constant value. .. The constant value includes an error.

In the embodiment, the third gas switching control unit 141C controls so that the third gas flows only to either the third gas addition line or the third gas discharge line, but the third gas is controlled. , May be controlled to flow to both the third gas addition line and the third gas discharge line.
In the embodiment, the fourth gas switching control unit 142C controls so that the third gas flows only to either the fourth gas addition line or the fourth gas discharge line, but the fourth gas is controlled. , The flow may be made to flow to both the fourth gas addition line and the fourth gas discharge line.

In the above embodiment, the pressure control mechanism 21 is configured to control the pressure of the third gas discharge line 13a3 and the fourth gas discharge line 14b3 (that is, a part of the discharge line 12) at once. Not limited. In another embodiment, the pressure control mechanism 21 may be configured to individually control the pressure of the third gas discharge line 13a3 and the fourth gas discharge line 14b3 which are a part of the discharge line 12.
Specifically, as shown in FIG. 5, the pressure adjusting unit 211, the second sensor 20, and the buffer tank are provided on each of the third gas discharge line 13a3 and the fourth gas discharge line 14b3. You may. Here, the valve control unit 213 has the pressure of the first gas line 11 output from the first sensor 19 and the third gas discharge line 13a3 (or the fourth gas) output from the second pressure sensor 20a (or 20b). The pressure is compared with the pressure of the discharge line 13b3) so that the difference between the pressure of the third gas discharge line 13a3 (or the fourth gas discharge line 13b3) and the pressure of the first gas line 11 becomes as small as possible. A signal for adjusting the opening degree is transmitted to the control valve 211a (or 211b).
In such a form, the pressure control mechanism 21 can individually control the pressures of the third gas discharge line 13a3 and the fourth gas discharge line 14b3, which are a part of the discharge line 12.

In the above embodiment, the third gas line 13a includes a third gas flow rate resistance 13a1 such as a capillary, but in other embodiments, the third gas line 13a includes a third gas flow rate resistance 13a1. It does not have to be. Similarly, the fourth gas line 13b may not be provided with the fourth gas flow rate resistance 13b1.

In addition, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

According to the present invention, even when the state in which the added gas is added to the first gas line and the state in which the added gas is discharged to the discharge line are alternately switched, the addition added to the first gas line is performed. It is possible to provide a simulated gas generator or the like capable of controlling the flow rate of gas with good responsiveness.

Claims (13)

A simulated gas generator in which an additive gas is added to a first gas to generate a simulated gas, and the simulated gas is supplied to a predetermined evaluation target.
The first gas line through which the first gas, which is the base of the simulated gas, flows,
Discharge line for gas discharge and
The additive gas line through which the additive gas flows and the additive gas line
A switching connection mechanism that switchesably connects the added gas line to the first gas line or the discharge line,
A first sensor that detects the pressure or temperature of the first gas line,
The first sensor detected so as to reduce the pressure difference between the first gas line and the discharge line when the connection destination of the added gas line switches from the discharge line to the first gas line. A simulated gas generator comprising a pressure control mechanism for controlling the pressure of the discharge line based on the pressure or temperature of the gas line. The pressure control mechanism
The pressure control unit provided on the discharge line and
The simulated gas generator according to claim 1, further comprising a control circuit for controlling the pressure adjusting unit based on the pressure or temperature output from the first sensor. The pressure control mechanism is provided on the upstream side of the pressure adjusting unit of the discharge line, and further includes a second sensor for detecting the pressure or temperature of the discharge line.
The simulated gas generator according to claim 2, wherein the control circuit controls the pressure adjusting unit based on the pressure or temperature output from the first sensor and the pressure or temperature output from the second sensor. The simulated gas generator according to claim 3, wherein the pressure control mechanism controls so as to reduce the difference between the pressure output from the first sensor and the pressure output from the second sensor. .. The third or fourth aspect of the present invention, wherein the pressure control mechanism controls the difference between the pressure output from the first sensor and the pressure output from the second sensor to be a constant value. Simulated gas generator. The simulated gas generator according to claim 1, 2, 3, 4 or 5, further comprising a pressure control gas line for supplying the pressure control gas to the discharge line. The simulated gas generator includes an evaluation target installation unit arranged on the first gas line and a heating furnace for heating the first gas.
The heating furnace is arranged on the upstream side of the evaluation target installation portion, and the first gas line and the added gas line are located between the heating furnace and the evaluation target installation portion or in the heating furnace. The simulated gas generator according to any one of claims 1 to 6, which is merging. The simulated gas generator according to claim 7, wherein the first sensor is provided on the upstream side of the confluence of the first gas line and the added gas line. The simulated gas generator according to claim 7 or 8, wherein the first sensor is arranged upstream of the heating furnace. Any of claims 1 to 9, wherein the added gas is a plurality of types of gases independently added to the first gas line, and the added gas line is provided with the switching connection mechanism, respectively. The simulated gas generator described. The simulated gas generator according to any one of claims 1 to 10, wherein a simulated gas that simulates exhaust gas discharged from an internal combustion engine is generated. An evaluation device for evaluating the evaluation target, comprising the simulated gas generator according to claim 1 and an analyzer for analyzing the components of the simulated gas.
An evaluation device in which the evaluation target is a catalyst, a sensor, or an aftertreatment system including the catalyst and the sensor. It is a simulated gas generation method using a simulated gas generator in which an additive gas is added to a first gas to generate a simulated gas, and the simulated gas is supplied to a predetermined evaluation target.
The simulated gas generator is
The first gas line through which the first gas, which is the base of the simulated gas, flows,
Discharge line for gas discharge and
The additive gas line through which the additive gas flows and the additive gas line
A switching connection mechanism that switchesably connects the added gas line to the first gas line or the discharge line,
A first sensor that detects the pressure or temperature of the first gas line,
It is provided with a pressure control mechanism for controlling the pressure of the discharge line.
The first sensor detected so as to reduce the pressure difference between the first gas line and the discharge line when the connection destination of the added gas line switches from the discharge line to the first gas line. A simulated gas generation method comprising controlling the pressure of the discharge line based on the pressure or temperature of the gas line.

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