JP4925492B1 - Test gas generator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a test gas generation device capable of instantly switching the density of liquid in test gas to an optional setting density, maintaining the density of the liquid constant in each setting density and generating test gas including liquid in a mist state. <P>SOLUTION: A test gas generation device includes a mixture part 3, 4 for receiving the supply of liquid and carrier gas and emitting the carrier gas mixed with the liquid, a cooling part 10 for cooling the mixture part, a test gas generation chamber 9 for receiving the supply of the carrier gas mixed with the liquid from the mixture part, receiving the supply of dilution gas, and generating test gas, a heating part 16 for heating the test gas generation chamber, and a control part 19 for controlling the supply amounts of the liquid, the carrier gas and the dilution gas, and the operation of the heating part. The test gas generation device generates test gas by vaporizing the liquid, vaporizing the liquid in a mist state, or vaporizing a portion of the liquid and mixing the rest portions in the mist state with the dilution gas in the test gas generation chamber. <P>COPYRIGHT: (C)2013,JPO&amp;INPIT

Description

  The present invention relates to a test gas generation apparatus that generates a test gas used in an apparatus or the like for evaluating the performance of an exhaust gas purification catalyst.

In order to reduce air pollution caused by automobile exhaust, automobile exhaust regulations are being implemented mainly in Japan, the United States and Europe, and these regulations tend to be tightened in stages. Automobile exhaust gas regulations are discharged from the internal combustion engine of a motor vehicle, nitrogen oxides _(NO X), carbon monoxide (CO), hydrocarbons (HC), non-methane hydrocarbons (NMHC), particulate matter (PM) This is a regulation that sets the upper limit of air pollutants.

  In automobile exhaust gas regulations, test modes are defined, and for example, test modes such as JC08C mode and JC08H mode in Japan and LA4 mode in the United States are well known. Exhaust gas measurement tests are based on a set measurement method in which the vehicle is set on a chassis dynamometer and run in the specified test mode, and the amount of air pollutants in the exhaust gas during the test period is determined. Performed by measuring.

  In addition, in order to satisfy the automobile exhaust gas regulations, an exhaust gas purification device equipped with an exhaust gas purification catalyst is mounted on the exhaust system of the internal combustion engine of the automobile. And in order to meet the exhaust gas regulations which are strengthened year by year, it is indispensable to improve the performance of the exhaust gas purification catalyst. For this reason, research and development of the exhaust gas purification catalyst has been conducted so far.

An exhaust gas purification catalyst performance evaluation device is used for research and development of exhaust gas purification catalysts. In the exhaust gas purification catalyst performance evaluation apparatus, a test gas containing the same components as the exhaust gas from the internal combustion engine is usually used. The test gas is usually produced by using a test gas generation device to mix CO, CO ₂ , NO, NO ₂ , HC, N _2, etc., with water and This is done by mixing a gas obtained by heating and evaporating a liquid such as liquid HC.

  Conventional test gas generators include, for example, a liquid injection hole into which liquid is injected, a dilution gas injection hole into which a dilution gas for diluting liquid vaporized gas is injected, and a liquid injected from the liquid injection hole. A prechamber that is heated to become vaporized gas, a prechamber heating means for heating the prechamber, an injection nozzle that mixes and injects vaporized gas and dilution gas, and stores the injection nozzle, and vaporized gas A mixing chamber in which the dilution gas is heated while being diffused and mixed with each other to generate a mixed gas (test gas), a mixing chamber heating means for heating the mixing chamber, and a mixed gas (test gas) generated in the mixing chamber What has a mixed gas (test gas) supply port to supply is known (for example, refer to patent documents 1).

  In this test gas generator, the liquid is heated and vaporized in the front chamber, and the vaporized gas is supplied to the injection nozzle at a constant mass flow rate. The vaporized gas and the diluting gas are both injected from the injection nozzle into the mixing chamber in the gas phase, and are mixed at a constant mixing ratio while diffusing. In this case, since the mixing chamber is heated, the vaporized gas is not re-cooled and condensed. Therefore, if liquid and dilution gas are injected at a constant mass flow rate from the liquid injection hole and dilution gas injection hole, respectively, a constant concentration of mixed gas (test gas) is supplied from the mixed gas supply port at a constant mass flow rate. Is done.

  Then, the test gas is brought to the same temperature and concentration as the exhaust gas supplied to the exhaust gas purification device of the vehicle while traveling in the test mode, and introduced from the test gas generation device into the gas cell containing the catalyst. In addition, the performance of the catalyst is evaluated by measuring the gas concentration before and after the catalyst.

  In this case, in order to improve the accuracy of performance evaluation, the concentration of the test gas immediately before the catalyst in the gas cell is accurately reproduced, and the concentration change of the exhaust gas immediately before the catalyst in the exhaust gas purification device of the vehicle running in the test mode is accurately reproduced. It is important to change. By the way, in a running vehicle, the exhaust gas concentration immediately before the catalyst in the exhaust gas purification device always changes significantly with fluctuations in the rotational speed and load of the internal combustion engine. Therefore, in the performance evaluation of the exhaust gas purification catalyst, it is necessary to switch the concentration of the test gas immediately before the catalyst in the gas cell to an arbitrary concentration and make the concentration constant for each set concentration.

However, in the above-described conventional test gas generation apparatus, liquid is injected into the liquid injection hole from the liquid supply source through the liquid supply pipe, but the liquid supply pipe is also heated by heat conduction as the front chamber is heated. . Further, in this test gas generation device, when the amount of liquid supply is changed, the flow rate and flow rate of the liquid flowing in the liquid supply pipe change accordingly. For this reason, the liquid is vaporized randomly locally and temporally while flowing in the liquid supply pipe, and the liquid cannot be injected into the liquid injection hole at a constant mass flow rate. This random vaporization of the liquid was particularly remarkable when the set concentration of the vaporized gas was low, and therefore the liquid supply amount was small, and a small amount of liquid flowed through the liquid supply pipe at a low speed.
As a result, there is a problem that the vaporized gas concentration in the test gas cannot be maintained at the set concentration, and further, the vaporized gas concentration cannot be instantaneously switched to an arbitrary set concentration.

  Depending on the test mode, the vehicle may be cold-started. At the time of cold-start, the exhaust gas supplied to the exhaust gas purification catalyst in the exhaust gas purification device contains moisture and unburned HC.

The NO _X storage reduction catalyst captures (occludes) NO _X when the air-fuel ratio of the inflowing exhaust gas is lean, while it captures (occludes) NO _X when the air-fuel ratio of the inflowing exhaust gas is stoichiometric or rich. Reduce. In some internal combustion engines equipped with NO _X storage reduction catalysts, when the operation is lean and the exhaust gas purification performance of the catalyst is reduced, the liquid reducing agent is injected from the injection nozzle provided upstream of the catalyst. There are some which perform reduction purification by releasing NO _X from the catalyst (for example, see Patent Document 2).

In some internal combustion engines equipped with NO _X storage reduction catalysts, urea water is injected from an injection nozzle provided upstream of the catalyst, and exhaust gas and ammonia generated from the urea water are mixed and supplied to the catalyst. In some cases, the exhaust gas purification efficiency is increased (see, for example, Patent Document 3).

  However, the conventional test gas generation device cannot generate a test gas containing a mist-like liquid. Therefore, it is possible to accurately reproduce the state of exhaust gas at the time of cold start of an internal combustion engine, and a catalyst. The state of the exhaust gas supplied to the exhaust gas purifying apparatus of the type that injects the liquid reducing agent into the gas could not be accurately reproduced.

Japanese Patent Laid-Open No. 10-318888 Japanese Patent Laid-Open No. 2000-240429 JP 2006-29233 A

  The problem of the present invention is that the concentration of the liquid in the test gas can be instantaneously switched to an arbitrary set concentration, the liquid concentration can be kept constant for each set concentration, and a test gas containing a liquid in a mist state can be obtained. It is an object of the present invention to provide a test gas generation device that can be generated.

  In order to solve this problem, according to the present invention, a liquid supply source, a carrier gas supply source, and a mixture that receives the supply of the liquid and the carrier gas and releases the carrier gas mixed with the liquid. , A first conduit for supplying the liquid from the liquid supply source to the mixing unit, a first flow control valve provided in the first conduit, and the carrier gas supply source for the carrier A second conduit for supplying gas to the mixing section; a second flow control valve provided in the second conduit; a cooling section for cooling the mixing section; a supply source for dilution gas; and the mixing A supply of the carrier gas mixed with the liquid from a section, a supply of the dilution gas, and a test gas generation chamber for generating a test gas; and the dilution gas from the supply source of the dilution gas Living A third conduit for supplying to the chamber; a third flow control valve provided in the third conduit; a heating unit for heating the test gas generation chamber; the first flow control valve; The flow rate control valve, the third flow rate control valve, and a control unit for controlling the operation of the heating unit, thereby vaporizing the liquid in the carrier gas in the test gas generation chamber, Alternatively, the test gas is characterized in that the test gas is generated by vaporizing a part of the liquid in the mist state or by mixing the diluent gas with the dilution gas in the mist state. A generating device is provided.

  According to a preferred embodiment of the present invention, the mixing unit includes a first inlet that receives the liquid supply, a second inlet that receives the carrier gas supply, and the carrier gas mixed with the liquid. A mixing chamber having a discharge outlet; a mixing tube having one end connected to the outlet of the mixing chamber and the other end penetrating through a wall of the test gas generation chamber and projecting into the test gas generation chamber; The first conduit is connected to the first inlet of the mixing chamber, and the second conduit is connected to the second inlet, whereby the carrier gas mixed with the liquid is The other end of the mixing tube is discharged into the test gas generation chamber.

  According to still another preferred embodiment of the present invention, the mixing unit includes a two-fluid nozzle, one end connected to the injection port of the two-fluid nozzle, and the other end penetrating the wall of the test gas generation chamber. A mixing tube protruding into the test gas generation chamber, wherein the first conduit is connected to a liquid inlet of the two-fluid nozzle, while the second conduit is connected to a gas inlet of the two-fluid nozzle So that the carrier gas mixed with the liquid is discharged from the other end of the mixing tube into the test gas generation chamber.

  According to still another preferred embodiment of the present invention, the mixing unit has a double pipe in which the opening at one end is closed, the other end is tapered, and the opening at the other end is in the form of a two-fluid nozzle. And a mixing tube having one end connected to the opening of the other end of the double tube and the other end protruding through the wall of the test gas generation chamber into the test gas generation chamber. The first conduit is connected to the inner tube of the heavy tube, while the second conduit is connected to the outer tube of the double tube, so that the carrier gas mixed with the liquid is mixed with the mixed gas. The other end of the tube is discharged into the test gas generation chamber.

  According to another preferred embodiment of the present invention, the mixing part is composed of a mixing tube with one end bifurcated, and the other end of the mixing tube penetrates the wall of the test gas generation chamber and Projecting into the test gas generation chamber, the first conduit is connected to one branch of the one end of the mixing tube, and the second conduit is connected to the other branch of the one end of the mixing tube; Accordingly, the carrier gas mixed with the liquid is discharged from the other end of the mixing tube into the test gas generation chamber.

  According to still another preferred embodiment of the present invention, the third conduit is connected to a dilution gas supply port formed in a wall of the test gas generation chamber, and a central axis of the mixing tube is the dilution pipe. The mixing tube forms an acute angle or 90 ° with the central axis of the gas supply port, and the other end of the mixing tube extends into the test gas generation chamber from the dilution gas supply port.

  According to still another preferred embodiment of the present invention, the mixing unit includes a two-fluid nozzle attached to an inner wall surface of the test gas generation chamber, and the first conduit is connected to a liquid inlet of the two-fluid nozzle. While the second conduit is connected to the gas inlet of the two-fluid nozzle, whereby the carrier gas mixed with the liquid flows from the nozzle of the two-fluid nozzle to the test gas generation chamber Is released inside.

  According to still another preferred embodiment of the present invention, the test gas generation chamber forms a gas cell of an exhaust gas purification catalyst performance evaluation device, and the carrier gas mixed with the liquid is mixed in the test gas generation chamber. An exhaust gas purification catalyst is accommodated at a position spaced downstream from the discharge port and the dilution gas discharge port, and a test gas exhaust gas is disposed in a region downstream of the exhaust gas purification catalyst on the wall of the test gas generation chamber. There is an exit.

According to still another preferred embodiment of the present invention, the heating unit is an infrared furnace.
According to still another preferred embodiment of the present invention, the carrier gas supply source comprises the dilution gas supply source, and the second conduit is branched and connected to the third conduit.

  According to the present invention, even if the supply amount of the liquid to the test gas generation chamber changes due to the change in the set concentration of the vaporized liquid in the test gas, the liquid is always supplied with the carrier gas at a constant speed. Can be transported up to. The liquid can be supplied to the test gas generation chamber without being vaporized during transportation regardless of the amount of liquid supplied. Thereby, the concentration of the liquid in the test gas can be instantaneously switched to an arbitrary set concentration at an arbitrary timing, and the liquid concentration can be kept constant for each set concentration. Furthermore, by controlling the temperature in the test gas generation chamber, the liquid is vaporized or the liquid is misted or part of the liquid is vaporized in the test gas generation chamber, and the remaining part is misted. Can be mixed with a diluent gas to produce a test gas.

It is a longitudinal cross-sectional view which shows schematic structure of the test gas generation apparatus by one Example of this invention. It is a longitudinal cross-sectional view which shows the modification of the mixing part of the test gas production | generation apparatus shown by FIG. It is a longitudinal cross-sectional view which shows the modification of the mixing part of the test gas production | generation apparatus shown by FIG. It is a longitudinal cross-sectional view which shows the modification of the mixing part of the test gas production | generation apparatus shown by FIG. It is a longitudinal cross-sectional view which shows the modification of the mixing part of the test gas production | generation apparatus shown by FIG.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a longitudinal sectional view showing a schematic configuration of a test gas generation apparatus according to one embodiment of the present invention.
Referring to FIG. 1, a test gas generation apparatus according to the present invention receives a supply source 1 of liquid, a supply source 2 of carrier gas, and supply of liquid and carrier gas, and releases the carrier gas mixed with the liquid. A mixing unit is provided. Nitrogen is preferably used as the carrier gas, but a diluent gas described later or one component gas of the diluent gas may be used.

In this embodiment, the mixing unit includes a first inlet 3a that receives the supply of liquid, a second inlet 3b that receives the supply of carrier gas, and an outlet 3c that discharges the carrier gas mixed with the liquid. A chamber 3 is provided. The first inlet 3 a of the mixing chamber 3 is connected to the liquid supply source 1 through the first conduit 5, and the second inlet 3 b is connected to the carrier gas supply source 2 through the second conduit 6. ing. A first flow rate control valve 7 and a second flow rate control valve 8 are arranged in the first conduit 5 and the second conduit 6, respectively.
The mixing unit further includes a mixing tube 4 having one end 4a connected to the outlet 3c of the mixing chamber.

The test gas generation apparatus according to the present invention also receives a supply source 11 of a dilution gas and a carrier gas mixed with a liquid from a mixing unit, and also generates a test gas by receiving the supply of the dilution gas and generating a test gas. And a chamber 9.
A dilution gas supply port 14 is formed in the test gas generation chamber 9, and the dilution gas supply port 14 is connected to the dilution gas supply source 11 through the third conduit 12. A third flow control valve 13 is disposed in the third conduit 12.

  The third conduit 12 is provided with a stirrer 15 as necessary. As the stirrer 15, a mixing tube in which the inside of the tube is formed in a spiral shape or a tube having a swirl flow generating fin inside can be used. Thereby, the mixing of the diluted gas and the vaporized liquid can be accelerated, and the test gas having a stable concentration distribution can be rapidly formed.

  In the illustrated embodiment, the carrier gas supply source 2 and the dilution gas supply source 11 are provided independently. However, when the dilution gas is used as the carrier gas, the dilution gas supply source 11 is connected to the carrier gas supply source 11. A configuration in which the second conduit 6 is branched and connected to the third conduit 12 is also possible as a supply source.

  Further, the other end of the mixing tube 4 of the mixing unit penetrates the wall of the test gas generation chamber 9 and protrudes into the test gas generation chamber 9. In this case, as shown in FIG. 1, the central axis of the mixing tube 4 forms an acute angle or 90 ° with the central axis of the dilution gas supply port 14 of the test gas generation chamber 9, and the other end 4 b of the mixing tube 4 is It is preferable to extend inside the test gas generation chamber 9 rather than the dilution gas supply port 14.

The test gas generation apparatus according to the present invention further includes a cooling unit 10 that cools the mixing unit, and a heating unit 16 that heats the test gas generation chamber 9.
The cooling unit 10 preferably cools the region outside the test gas generation chamber 9 and in the vicinity of the connection portion of the mixing unit with the test gas generation chamber 9. In this embodiment, the cooling unit 10 is close to the test gas generation chamber 9. It arrange | positions so that the mixing pipe | tube 4 part to perform may be surrounded.
The cooling action of the cooling unit 10 prevents the mixing unit from being heated by heat conduction from the test gas generation chamber 9, thereby preventing liquid from being vaporized in the mixing unit.
Further, in order to suppress heat conduction from the test gas generation chamber 9, it is preferable that the contact area between the portion of the mixing tube 4 protruding into the test gas generation chamber 9 and the internal space of the test gas generation chamber 9 is small. It is preferable to use a small-diameter mixing tube 4.

It is preferable that the heating part 16 consists of an infrared furnace. Thereby, the temperature in the test gas generation chamber 9 can be controlled at high speed.
The test gas generation apparatus according to the present invention further includes a first flow control valve 7, a second flow control valve 8, a third flow control valve 13, and a control unit 19 that controls the operation of the heating unit 16. Yes. The cooling unit 10 may be controlled by the control unit 19 or may operate independently of the control unit 19.

In this embodiment, the test gas generation chamber 9 forms a gas cell of an exhaust gas purification catalyst performance evaluation apparatus. In the test gas generation chamber 9, the exhaust gas purification catalyst 17 whose performance is to be evaluated is disposed at a position spaced downstream from the dilution gas supply port 14 and the other end 4 b of the mixing pipe 4. In this case, the exhaust gas purification catalyst 17 is inserted into the test gas generation chamber 9 in a state in which the exhaust gas purification catalyst 17 is previously attached to the holder 18 and then held in the holder 18.
In addition, a test gas discharge port 9 a is provided in a region downstream of the exhaust gas purification catalyst 17 on the wall of the test gas generation chamber 9.

  In the above configuration, the liquid is supplied from the liquid supply source 1 to the mixing chamber 3 through the first conduit 5, and the carrier gas is supplied from the carrier gas supply source 2 to the mixing chamber 3 through the second conduit 6. The Then, the first flow rate control valve 7 and the second flow rate control valve 8 are controlled by the control unit 19, and the first flow rate control valve 7 controls the liquid so that the concentration of the liquid in the test gas becomes the set concentration. The supply amount of the carrier gas is adjusted by the second flow rate control valve 8 so that the supply amount is adjusted and the carrier gas mixed with the liquid always flows through the mixing pipe 4 at a constant speed. In addition, the cooling unit 10 operates to cool the mixing tube 4.

Further, the heating unit 16 operates to heat the test gas generation chamber 9, and the dilution gas is supplied from the dilution gas supply source 11 into the test gas generation chamber 9 through the third conduit 12. Then, the third flow control valve 13 is controlled by the control unit 19, and the supply amount of the dilution gas is adjusted by the third flow control valve 13 so that the concentration of the dilution gas in the test gas becomes the set concentration. .
Thus, the carrier gas mixed with the liquid is supplied to the test gas generation chamber 9 through the mixing tube 4 without being vaporized in the mixing tube 4. Then, by controlling the temperature in the test gas generation chamber 9 by the control unit 19, the liquid is vaporized and mixed with the dilution gas in the test gas generation chamber 9 according to the temperature in the test gas generation chamber 9. The test gas is generated, or the liquid is mixed with the dilution gas in the mist state to generate the test gas, or the liquid is partially vaporized and the remaining part is mixed with the dilution gas in the mist state. A test gas is generated.

  According to the test gas generation apparatus of the present invention, regardless of the amount of liquid supplied, the liquid is always transported to the test gas generation chamber together with the carrier gas at a constant speed without being vaporized, and is supplied to the test gas generation chamber. Can be supplied. Thereby, the concentration of the liquid in the test gas can be instantaneously switched to an arbitrary set concentration at an arbitrary timing, and the liquid concentration can be kept constant for each set concentration. Furthermore, by controlling the temperature in the test gas generation chamber, the liquid is vaporized or the liquid is misted or part of the liquid is vaporized in the test gas generation chamber, and the remaining part is misted. Can be mixed with a diluent gas to produce a test gas.

  When the test gas generation chamber of the test gas generation device of the present invention is a gas cell of the exhaust gas purification catalyst performance evaluation device, the concentration of the test gas is set in the exhaust gas purification device of the vehicle during cold start and traveling. The exhaust gas concentration change immediately before the catalyst can be changed so that it can be accurately reproduced.

  The configuration of the present invention has been described based on one preferred embodiment. However, the configuration of the present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the configuration described in the claims of this application. Can be created.

FIG. 2A and FIG. 2B are longitudinal sectional views showing modified examples of the mixing unit. 2A and 2B, the same components as those shown in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.
With reference to FIG. 2A, in this modification, the mixing unit includes a two-fluid nozzle 20 and a mixing tube 4 having one end 4a connected to an injection port 20c of the two-fluid nozzle. The other end 4 b of the mixing tube 4 penetrates the wall of the test gas generation chamber 9 and projects into the test gas generation chamber 9 as in the embodiment of FIG.

  The first conduit 5 is connected to the liquid inlet 20 a of the two-fluid nozzle 20, while the second conduit 6 is connected to the gas inlet 20 b of the two-fluid nozzle 20. Thereby, the carrier gas mixed with the liquid is discharged from the other end 4 b of the mixing tube 4 into the test gas generation chamber 9.

  In this modification, since the liquid is mixed with the carrier gas using the two-fluid nozzle 20, even when the liquid supply amount is small, the liquid is liquidated by the surface tension at the outlet of the liquid supply conduit of the nozzle 20. It is prevented from becoming droplets, so that the concentration of the liquid in the test gas can be precisely controlled.

  2B is different from the modification shown in FIG. 2A in the configuration of the two-fluid nozzle. That is, in the modification shown in FIG. 2A, a two-fluid nozzle that mixes liquid and gas (carrier gas) outside the nozzle is used, whereas in the modification shown in FIG. A two-fluid nozzle that mixes gas (carrier gas) inside the nozzle is used.

In the modification shown in FIG. 2B, a cap 21 is attached to the injection port 20 c of the two-fluid nozzle 20, and an injection port 21 a is formed at the tip of the cap 21. Then, the liquid and the carrier gas are mixed inside the cap 21, and the carrier gas mixed with the liquid is discharged into the mixing tube 4 from the ejection port 21 a of the cap 21.
In this modified example, as in the modified example shown in FIG. 2A, even when the amount of liquid supply is small, the liquid drops at the outlet of the liquid supply line of the two-fluid nozzle 20 due to surface tension. The concentration of the liquid in the test gas can be precisely controlled.

FIG. 3 is a longitudinal sectional view showing still another modification of the mixing unit. In FIG. 3, the same components as those shown in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.
Referring to FIG. 3, in this modification, the mixing unit includes a double tube 22 having an opening at one end, a tapered end at the other end, and an opening 22 c at the other end in the form of a two-fluid nozzle. The mixing tube 4 is connected to the opening 22c at the other end of the double tube 22 at one end 4a. The other end 4 b of the mixing tube 4 penetrates the wall of the test gas generation chamber 9 and protrudes into the test gas generation chamber 9 as in the embodiment shown in FIG.

The first conduit 5 is connected to the inner tube 22 a of the double tube 22, while the second conduit 6 is connected to the outer tube 22 b of the double tube 22. Thereby, the carrier gas mixed with the liquid is discharged from the other end 4 b of the mixing tube 4 into the test gas generation chamber 9.
Also in this modified example, since the liquid is mixed with the carrier gas using the two-fluid nozzle as in the modified example shown in FIG. 2, even if the supply amount of the liquid is small, the double tube 21 At the outlet of the inner tube 22a, the liquid is prevented from becoming droplets due to the surface tension, whereby the concentration of the liquid in the test gas can be accurately controlled.

FIG. 4 is a longitudinal sectional view showing still another modification of the mixing unit. In FIG. 4, the same components as those shown in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.
Referring to FIG. 4, in this modification, the mixing section is composed of a mixing tube 4 having one end 4a bifurcated. The other end 4 b of the mixing tube 4 penetrates the wall of the test gas generation chamber 9 and protrudes into the test gas generation chamber 9 as in the embodiment shown in FIG.

  The first conduit 5 is connected to one branch 4 c at one end 4 a of the mixing tube 4, and the second conduit 6 is connected to the other branch 4 d of one end 4 a of the mixing tube 4. Thereby, the carrier gas mixed with the liquid is discharged from the other end 4 b of the mixing tube 4 into the test gas generation chamber 9.

FIG. 5 is a longitudinal sectional view showing still another modification of the mixing unit. In FIG. 5, the same components as those shown in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.
Referring to FIG. 5, in this modification, the mixing unit includes a two-fluid nozzle 23 attached to the inner wall surface of the test gas generation chamber 9, and the first conduit 5 is connected to the liquid inlet 23 a of the two-fluid nozzle 23. Is connected to the gas inlet 23 b of the two-fluid nozzle 22. Accordingly, the carrier gas mixed with the liquid is discharged into the test gas generation chamber 9 from the injection port 23 c of the two-fluid nozzle 23.

Also in this modified example, since the liquid is mixed with the carrier gas using the two-fluid nozzle 23, even if the liquid supply amount is small, the liquid is caused by surface tension at the outlet of the liquid supply conduit of the nozzle 23. It is prevented from becoming droplets, whereby the concentration of the liquid in the test gas can be accurately controlled.
In this modification, a two-fluid nozzle that mixes liquid and gas outside the nozzle is used. Instead, a two-fluid nozzle that mixes liquid and gas inside the nozzle is used. You can also.

DESCRIPTION OF SYMBOLS 1 Liquid supply source 2 Carrier gas supply source 3 Mixing chamber 3a First inlet 3b Second inlet 3c Outlet 4 Mixing tube 4a One end 4b Other end 5 First conduit 6 Second conduit 7 First flow control Valve 8 Second flow control valve 9 Test gas generation chamber 9a Test gas discharge port 10 Cooling unit 11 Dilution gas supply source 12 Third conduit 13 Third flow control valve 14 Dilution gas supply port 15 Stirrer 16 Heating unit 17 Exhaust gas purification catalyst 18 Holder 19 Control unit 20 Two-fluid nozzle 20a Liquid inlet 20b Gas inlet 20c Injector 21 Cap 21a Injector 22 Double pipe 22a Inner pipe 22b Outer pipe 22c Other end opening 23 Two-fluid nozzle 23a Liquid introduction 23b Gas introduction port 23c Injection port

Claims (10)

A source of liquid;
A carrier gas source;
A mixing unit for receiving the supply of the liquid and the carrier gas and discharging the carrier gas mixed with the liquid;
A first conduit for supplying the liquid to the mixing unit from the liquid source;
A first flow control valve provided in the first conduit;
A second conduit for supplying the carrier gas to the mixing unit from the carrier gas supply source;
A second flow control valve provided in the second conduit;
A cooling unit for cooling the mixing unit;
A source of dilution gas;
A test gas generation chamber that receives the supply of the carrier gas mixed with the liquid from the mixing unit, receives the supply of the dilution gas, and generates a test gas;
A third conduit for supplying the dilution gas from the dilution gas source to the test gas generation chamber;
A third flow control valve provided in the third conduit;
A heating unit for heating the test gas generation chamber;
A control unit that controls the operation of the first flow rate control valve, the second flow rate control valve, the third flow rate control valve, and the heating unit. The test gas is generated by vaporizing a liquid or by vaporizing the liquid in a mist state or by vaporizing a part of the liquid and mixing the remaining portion with the dilution gas in the mist state. A test gas generator characterized by the above. The mixing unit includes:
A mixing chamber having a first inlet receiving the supply of liquid, a second inlet receiving the supply of carrier gas, and an outlet for discharging the carrier gas mixed with the liquid;
One end connected to the outlet of the mixing chamber and the other end protruding through the wall of the test gas generation chamber into the test gas generation chamber;
The first conduit is connected to the first inlet of the mixing chamber, and the second conduit is connected to the second inlet, whereby the carrier gas mixed with the liquid is supplied to the mixing tube. The test gas generation device according to claim 1, wherein the test gas generation device is discharged from the other end of the gas into the test gas generation chamber. The mixing unit includes:
A two-fluid nozzle;
One end of which is connected to the injection port of the two-fluid nozzle and the other end of which passes through the wall of the test gas generation chamber and protrudes into the test gas generation chamber;
The first conduit is connected to the liquid inlet of the two-fluid nozzle, while the second conduit is connected to the gas inlet of the two-fluid nozzle, whereby the carrier gas mixed with the liquid The test gas generation device according to claim 1, wherein the gas is discharged from the other end of the mixing tube into the test gas generation chamber. The mixing unit includes:
A double tube in which the opening at one end is closed and the other end is tapered, and the opening at the other end is in the form of a two-fluid nozzle;
One end connected to the opening of the other end of the double pipe, and the other end protruding through the wall of the test gas generation chamber into the test gas generation chamber,
The first conduit is connected to the inner tube of the double tube, while the second conduit is connected to the outer tube of the double tube, whereby the carrier gas mixed with the liquid is The test gas generation apparatus according to claim 1, wherein the test gas generation apparatus is discharged into the test gas generation chamber from the other end of the mixing tube.   The mixing section is composed of a mixing pipe having one end bifurcated, and the other end of the mixing pipe penetrates the wall of the test gas generation chamber and protrudes into the test gas generation chamber. The carrier gas in which the first conduit is connected to one branch of the one end and the second conduit is connected to the other branch of the one end of the mixing tube, and thereby the liquid is mixed. The test gas generation device according to claim 1, wherein the gas is discharged from the other end of the mixing tube into the test gas generation chamber.   The third conduit is connected to a dilution gas supply port formed in a wall of the test gas generation chamber, and a central axis of the mixing tube forms an acute angle or 90 ° with a central axis of the dilution gas supply port. The test gas generation device according to any one of claims 2 to 5, wherein the other end of the mixing tube extends inside the test gas generation chamber from the dilution gas supply port.   The mixing unit includes a two-fluid nozzle attached to an inner wall surface of the test gas generation chamber, and the first conduit is connected to the liquid inlet of the two-fluid nozzle, while the gas introduction of the two-fluid nozzle The said 2nd conduit | pipe is connected to an opening | mouth, The said carrier gas mixed with the said liquid is discharge | released in the said test gas production | generation chamber from the injection opening of the said 2 fluid nozzle, The said 1st aspect is characterized by the above-mentioned. A test gas generator according to claim 1.   The test gas generation chamber forms a gas cell of an exhaust gas purification catalyst performance evaluation device, and is downstream from the carrier gas discharge port and the dilution gas discharge port mixed with the liquid in the test gas generation chamber. The exhaust gas purification catalyst is accommodated at a position spaced apart from the exhaust gas purification catalyst, and a test gas discharge port is provided in a region downstream of the exhaust gas purification catalyst on the wall of the test gas generation chamber. The test gas production | generation apparatus in any one of Claims 1-7. The test gas generation apparatus according to claim 1, wherein the heating unit is an infrared furnace.   10. The carrier gas supply source comprises the dilution gas supply source, and the second conduit is branchedly connected to the third conduit. Test gas generator.

Images