JP3818916B2 - Internal combustion engine with exhaust purification device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to NO contained in the exhaust gas of an internal combustion engine._XThe present invention relates to an internal combustion engine equipped with an exhaust purification device that can remove harmful components such as HC and HC.
[0002]
[Prior art]
  NO contained in exhaust gas discharged from internal combustion engines_XIn general, harmful components such as these are removed by providing a filter for removing catalyst and exhaust particulates in the exhaust passage to discharge clean exhaust gas. However, the post-treatment device such as the catalyst and the filter is expensive and the purification performance is deteriorated due to deterioration with time and the S (sulfur) component contained in the fuel. In addition, the filter is clogged with fine particles such as soot, and it is difficult to always exhibit the expected purification performance, and the use conditions are limited.
[0003]
  Further, as an apparatus for purifying exhaust gas by combustion, there is "Exhaust gas treatment device for internal combustion engine with exhaust turbine supercharger" disclosed in Japanese Patent Application No. 59-534, filed by the present applicant. However, in Japanese Patent Laid-Open No. 59-534, a combustor is provided in the exhaust passage in order to improve the startability of the internal combustion engine, and it is possible to purify exhaust gas discharged at low load or low speed operation. However, exhaust gas discharged at high load and high speed operation cannot be purified. Unburned HC can be purified (oxidized), but NO_XCould not be purified (reduced).
[0004]
[Problems to be solved by the invention]
  Therefore, the present invention provides an internal combustion engine provided with an exhaust gas purification device that can purify harmful components contained in exhaust gas in the full load region and the full operation range (low speed, medium speed, and high speed). It is said.
[0005]
[Means for Solving the Problems]
  In order to solve the above problems, in the invention of claim 1, a combustor is provided in the exhaust passage of the internal combustion engine,An excess air ratio control for controlling an excess air ratio and a combustion temperature in the combustor in an internal combustion engine equipped with an exhaust gas purification device that purifies harmful components contained in the exhaust gas by combustion in the combustor. And an engine temperature detecting means for detecting the engine speed of the internal combustion engine, an exhaust temperature detecting means, a supply air pressure detecting means, and a detection signal obtained by these detecting means. Exhaust gas exhaust for detecting the amount of exhaust gas exhausted from the combustion chamber of the internal combustion engine by providing an excess air ratio calculating means for calculating the excess air ratio of exhaust gas generated in the combustion chamber and an engine output calculating means for calculating the engine output An excess air ratio control unit is provided with an excess air ratio calculated by the excess air ratio calculation means and an exhaust gas emission amount obtained by the exhaust gas emission amount detection means. Capable of changing within a range of desired more excess air ratio detected possible and detecting the excess air ratio λ in the combustion λdid.
[0006]
  In the invention of claim 2, in the invention of claim 1,A fuel supply amount adjusting means is provided as the excess air ratio control means, and the amount of fuel supplied to the combustor is controlled by the fuel supply amount adjusting means so that the excess air ratio in the combustor can be controlled..
[0007]
  In the invention of claim 3, in the invention of claim 1,As the excess air ratio control means, a fuel supply amount adjusting means and an air supply amount adjusting means are provided..
[0008]
  The invention of claim 4 claims3In the invention ofAs the air supply amount adjusting means, a compressed air supply means by a compressor is provided..
[0009]
  The invention of claim 5 claims1In the invention ofThe total amount of exhaust gas from the internal combustion engine is supplied to the combustion region in the combustor.
[0010]
  In the invention of claim 6, in the invention of claim 1,Adjustment capable of adjusting the amount of exhaust gas supplied to the combustion region for purifying the exhaust gas in the combustor and the amount of exhaust gas supplied to the dilution region for reducing the temperature of the purified exhaust gas downstream from the combustion region Equipped with means.
[0011]
  In the invention of claim 7, the claim1In the invention ofThe excess air ratio λ is set in the range of λ ≦ 1.2 in the combustor, and NO in exhaust gas _X An upstream combustion region for purifying the exhaust gas is provided, and the excess air ratio λ is set in the range of 1.0 <λ on the downstream side of the upstream combustion region to purify particulates such as HC, CO, and soot in the exhaust gas. NO in the exhaust gas in the upstream combustion region and the downstream combustion region _X Purifies fine particles such as HC, CO and sootI did it.
[0012]
  In the invention of claim 8, in the invention of claim 1,An upstream combustion region for purifying particulates such as HC, CO and soot in exhaust gas by setting an excess air ratio λ in a range of 1.0 <λ on the upstream side in the combustor is provided, and the upstream combustion The excess air ratio λ is set in the range of 1.0 ≦ λ ≦ 1.2 on the downstream side of the region, and NO in the exhaust gas _X NO is contained in the exhaust gas in the upstream combustion region and the downstream combustion region. _X Purifies fine particles such as HC, CO and sootI did it.
[0013]
  The invention of claim 9 claims1In the invention ofThe excess air ratio λ is set in the range of λ <1.0 on the upstream side in the combustor, and NO in the exhaust gas _X An upstream combustion region for purifying the exhaust gas is provided, and the excess air ratio λ is set in the range of 1.4 <λ on the downstream side of the upstream combustion region to purify particulates such as HC, CO and soot in the exhaust gas. NO in the exhaust gas in the upstream combustion region and the downstream combustion region _X Purifies fine particles such as HC, CO and sootI did it.
[0014]
  The invention of claim 10 claims7-9In any of the inventions,All exhaust gas supplied to the upstream combustion area of the combustor is supplied to the downstream combustion areadid.
[0015]
  The invention of claim 11 claims7-9In one of the inventions, a branch passage is provided for supplying exhaust gas generated in the internal combustion engine to the upstream combustion region and the downstream combustion region of the combustor, and the exhaust gas supplied to the upstream combustion region is Supply to the downstream combustion area.
[0016]
  The invention of claim 12 claimsAny of 7-9In the invention ofA dilution region for lowering the temperature of the exhaust gas after purification is provided further downstream than the downstream combustion region, and the exhaust gas generated in the internal combustion engine is sent to the upstream combustion region, the downstream combustion region of the combustor, and A branch passage for supplying to the dilution region is provided, and exhaust gas purified in the upstream combustion region can be supplied to the downstream combustion region..
[0017]
  The invention of claim 13 claims10-12In any of the inventions,Provided with adjusting means for adjusting the amount of exhaust gas supplied directly to the upstream combustion region and the downstream combustion region.
[0018]
  In the invention of claim 14, it is claimed1,10-12In any of the inventions,A part of the exhaust gas generated in the internal combustion engine can be directly supplied to the dilution region downstream of the combustion region in the combustor, and the temperature of the exhaust gas purified in the combustion region is lowered..
[0019]
  The invention of claim 15 claims1,10-12In any of the inventions,Compressed air generated by the compressor can be supplied to the dilution region downstream of the combustion region in the combustor, and the temperature of the exhaust gas purified in the combustion region is lowered..
[0020]
  The invention of claim 16 claimsOne of 1,10-12In the invention ofA heat exchanger that generates steam from the exhaust gas of the internal combustion engine is provided, and the steam generated by the heat exchanger can be supplied to the dilution region downstream of the fuel region in the combustor..
[0021]
DETAILED DESCRIPTION OF THE INVENTION
  Figure1 isBook1 is a system schematic diagram showing a fuel supply path, an air supply path, an exhaust gas discharge path, and a signal transmission path of an internal combustion engine equipped with an exhaust emission control device according to the invention. Fuel (for example, hydrocarbon fuel such as gasoline, heavy oil, light oil, etc.) is supplied from the fuel tank 29 through the fuel supply pipe 9 to the internal combustion engine body 1, and air (compressed air) is supplied through the air supply pipe 16. The
[0022]
  Combustion is performed in a combustion chamber (not shown) of the internal combustion engine body 1, and power is transmitted (output) to the generator 6 via the drive shaft 17. Further, exhaust gas containing harmful components is exhausted through the exhaust pipe 24 (exhaust passage).
[0023]
  The exhaust pipe 24 is connected to the combustor 2, and exhaust gas flows into the combustor 2. Further, fuel can be supplied to the combustor 2 via a fuel supply pipe 10 that branches from the fuel supply pipe 9 and includes a metering valve 11 in the middle. Further, compressed air can be supplied to the combustor 2 via a compressed air supply pipe 15 branched from a compressed air supply pipe 14 described later and provided with a metering valve 12 in the middle.
[0024]
  As shown in FIG. 1, an exhaust pipe 25 is connected to the downstream side of the combustor 2, and the exhaust gas in the combustor 2 is combusted by the fuel and compressed air supplied to the combustor 2. It can be discharged through the exhaust pipe 25 later.
[0025]
  A turbine 3 is provided on the downstream side of the exhaust pipe 25. The exhaust gas discharged from the combustor 2 through the exhaust pipe 25 rotates the turbine 3, drives the compressor 4 through the drive shaft 27, and drives the generator 7 through the drive shaft 18. The exhaust gas that has rotated the turbine 3 is discharged to the outside (in the atmosphere) through the exhaust pipe 26.
[0026]
  The compressor 4 driven by the drive shaft 27 sucks air from the air intake pipe 13 and generates compressed air. The generated compressed air is supplied to the intercooler 5 through the compressed air supply pipe 14. The compressed air is cooled by the cooling water supplied through the cooling water supply pipe 60 in the intercooler 5 and can be supplied to the combustion chamber (not shown) of the internal combustion engine body 1 through the air supply pipe 16. .
[0027]
  A supply air pressure (boost pressure) detection sensor 19 is provided in the vicinity of the connection portion between the supply pipe 16 and the internal combustion engine body 1. The combustor 2 is provided with a temperature sensor 28, and the temperature sensor 28 detects the temperature in the combustor 2. Further, the exhaust pipe 24 is provided with an exhaust gas flow meter 21, an oxygen sensor 22, and an exhaust temperature sensor 23. Detection signals detected by these sensors are transmitted to the ECU 8 (computer unit having a memory) via signal lines.
[0028]
  When these detection signals are input, the ECU 8 adjusts the opening degree of the metering valves 11 and 12 so as to satisfy various conditions to be described later, and supplies the required amount of fuel and air into the combustor 2. The excess air ratio λ and the combustion temperature in the combustor 2 can be adjusted. In other words, the excess air ratio control means and theseCombustion temperature control meansAnd are configured.
[0029]
  The internal volume of the combustor 2 is known, and the exhaust gas amount and oxygen concentration in the combustor 2 are calculated by the ECU 8 based on detection signals detected by the oxygen sensor 22 and the exhaust gas flow meter 21 (exhaust gas emission amount detection means). To calculate.
[0030]
  Further, the engine output can be obtained from detection signals detected by the engine speed detection sensor 20, the supply air pressure detection sensor 19 and the exhaust temperature sensor 23, and the exhaust pipe is obtained from the engine output and the supply air pressure detected by the supply air pressure detection sensor 19. The ECU 8 calculates the excess air ratio λ of the exhaust gas in 24 and the combustor 2.
[0031]
  The harmful components to be purified contained in the exhaust gas in the combustor 2 are NO._XThis excess air ratio λ is set as described in each of the examples described later, depending on whether it is fine particles such as unburned HC, CO and soot. The temperature in the combustor 2 is detected by the temperature sensor 28, but the ECU 8 calculates and calculates the amount of fuel and compressed air necessary for raising the temperature in the combustor 2 to a desired temperature. The fuel and air (compressed air) are supplied to the combustor 2 by adjusting the opening of the metering valves 11 and 12 so that the fuel and air (compressed air) can be supplied to the combustor 2.
[0032]
  Here, the compressed air generated by the compressor 4 is supplied to the combustor 2, but the air supplied to the combustor 2 is supplied by the compressor provided separately from the compressor 4. It may be.
[0033]
  InsideWhen combustion is performed in a combustion chamber (not shown) of the combustion engine body 1, NO is contained in the exhaust gas passing through the exhaust pipe 24._XIs contained in large quantities. In this case, the ECU 8 adjusts the opening degree of the metering valves 11 and 12 so that the excess air ratio λ in the combustor 2 falls within the range of 1.0 ≦ λ ≦ 1.2. Supply to the combustor 2.
[0034]
  Further, the ECU 8 calculates the required amount of fuel and air (compressed air) so that the oxygen concentration in the combustor 2 is less than 10% and the combustion temperature T is 800 ° C. <T <1500 ° C. In addition, the opening amount of the metering valves 11 and 12 is adjusted so that the calculated amount of fuel and air can be supplied to the combustor 2, and the fuel and air are supplied to the combustor 2. adjust.
[0035]
  FIG. 14 shows NO when the oxygen concentration in the combustor 2 is set to less than 10% and the excess air ratio is changed._XIt is a graph which shows the purification rate. The flow rate of the exhaust gas is 5 L / min (liter / minute) in the standard state. From FIG. 14, it can be seen that if the excess air ratio is 0.2 to 1.0, a high purification rate of about 90% is exhibited.
[0036]
  InsideWhen combustion is performed with an excess air ratio λ in the combustion chamber of the combustion engine body 1 of λ <1, a large amount of unburned HC, CO, and PM (fine particles of soot and the like) are present in the exhaust gas passing through the exhaust pipe 24. include. In this case, the ECU 8 adjusts the opening of the metering valves 11 and 12 so that the excess air ratio λ in the combustor 2 falls within the range of 1.0 <λ (preferably 1.4 <λ), and the fuel And compressed air are supplied to the combustor 2.
[0037]
  Further, the ECU 8 can calculate the required amount of fuel and air and supply the calculated amount of fuel and air to the combustor 2 so that the combustion temperature T in the combustor 2 becomes 1300 ° C. <T <1500 ° C. Then, the opening degree of the metering valves 11 and 12 is adjusted, fuel and air are supplied to the combustor 2, and the temperature in the combustor 2 is adjusted.
[0038]
  FIG. 16 shows the combustion temperature in the combustor 2 and the CO and NO in the exhaust gas._XIt is a graph which shows the relationship of the tendency of purification. If the combustion temperature is low, the amount of CO emissions increases. Conversely, if the combustion temperature is high, NO_XThe amount of emissions increases. According to FIG. 16, when the range of the combustion temperature T is limited to 1300 ° C. <T <1500 ° C., CO, NO_XIt can be seen that both of these are relatively well purified.
[0039]
  Figure2 is a schematic cross-sectional view of the combustor 2 of FIG. 1 according to the present invention. In the combustor 2 of FIG. 2, the entire amount of exhaust gas discharged from the internal combustion engine main body 1 can flow into the combustor 2 from the exhaust gas inlet 74 of the combustor inner cylinder 51. The inflow amount of exhaust gas per unit time can be adjusted by sliding the movable portion 53 of the opening / closing mechanism 52 provided at the exhaust gas intake 74 in the direction indicated by the arrow A.
[0040]
  The exhaust gas flowing in from the exhaust gas inlet 74 passes through the swirl vane 35 and enters the inner cylinder 51. A pipe 15a (branched portion not shown) branched from the compressed air supply pipe 15 so that air (compressed air) 38a can also flow in from the exhaust gas inlet 74 is an outer cylinder 50 on the upstream side of the inner cylinder 51. It is connected to the.
[0041]
  The fuel supply pipe 10 is accommodated in a protective pipe 75 and is protected from high-temperature exhaust gas. As shown in FIG. 2, a fuel injection valve 76 is provided at the tip of the fuel supply pipe 10, and fuel 37 is injected from the fuel injection valve 76 into the inner cylinder 51 of the combustor 2. A spark plug 30 is provided in the inner cylinder 51, and the fuel 37, the exhaust gas 77 and the air 38 a ignited by the spark plug 30 are combusted in the combustion region 31 in the inner cylinder 51.
[0042]
  The ratio (the excess air ratio) of the fuel 37 to be injected and the air 38a including the exhaust gas 77 is adjusted by adjusting the injection amount of the fuel 37 from the fuel injection valve 76 or by moving the movable portion 53 of the opening / closing mechanism 52 with the arrow A. It can be changed by adjusting the amount of air flowing into the combustion region 31 by sliding in the direction.
[0043]
  A dilution region 32 is provided on the downstream side of the combustion region 31. A dilution hole 33 is provided in the inner cylinder 51 of the dilution region 32. The compressed air 38 supplied from the compressed air supply pipe 15 flows in the annular passage 39 formed between the inner cylinder 51 and the outer cylinder 50 of the combustor 2, and passes from the dilution hole 33 to the dilution region 32 in the inner cylinder 51. It flows in as dilution gas 40. In the dilution region 32, the exhaust gas after combustion in the combustion region 31 and the dilution gas 40 flowing in from the dilution hole 33 are mixed, and the high-temperature exhaust gas after combustion is diluted into the dilution gas 40, for example, 900 It is cooled to about ℃ or less.
[0044]
  Figure3 isBookOf the combustor 2 of FIG. 1 according to the invention.Another exampleFIG. 3 is different from the combustor 2 of FIG. 2 in that the exhaust gas 77 is mixed into the diluted gas 34 flowing into the inner cylinder 51 from the dilution hole 33. In FIG. 3, the configuration denoted by the same reference numerals as those in FIG. 2 is basically the same as the configuration in FIG.
[0045]
  A part of the compressed air 38 supplied from the compressed air supply pipe 15 flows into the combustion region 31 from the exhaust gas intake port 74, and a further part of the remaining part passes through the bypass passage 36 and passes from the dilution hole 33 to the inner cylinder. It flows into the dilution region 32 in 51.
[0046]
  A part of the exhaust gas 77 also flows into the combustion region 31 from the exhaust gas inlet 74, and a further part of the remaining portion flows into the dilution region 32 of the inner cylinder 51 from the dilution hole 33 through the bypass passage 36. . Here, the bypass passage 36 on the downstream side of the dilution hole 33 may be closed so that the dilution gas 34 (exhaust gas or a mixture of air and exhaust gas) passing through the bypass passage 36 flows into the dilution region 32.
[0047]
  Figure 4BookOf the combustor 2 of FIG. 1 according to the invention.Another exampleFIG. The configuration of the combustor 2 shown in FIG. 4 is different from the configuration of FIG. 2 in that the combustion region 31 and the dilution region 32 are provided in the inner cylinder 51 in FIG. The first combustion region 41, the second combustion region 42, and the dilution region 43 are provided. These regions are partitioned by broken lines in FIG.
[0048]
  In FIG. 4, the first combustion region 41 is supplied with the entire amount of exhaust gas 77 and compressed air 38a. The inflow amount of the exhaust gas 77 and the compressed air 38a is adjusted by the opening / closing mechanism 52, and the injection amount of the fuel 37 is adjusted by the ECU 8 in FIG.₁Λ₁Adjust within the range of ≦ 1.2.
[0049]
  The exhaust gas burned in the first combustion region 41 flows into the second combustion region 42 as it is. An annular first passage 45 is formed on the outer periphery of the inner cylinder 50. The first passage 45 communicates with the compressed air supply pipe 15. Further, a second passage 46 communicating with the inner cylinder 50 is provided on the inner peripheral side of the first passage 45. The compressed air 38 can flow from the second passage 46.
[0050]
  A secondary fuel supply pipe 44 is connected to the second passage 46 so that the fuel 37 a can be supplied to the second passage 46. The excess air ratio λ of the air-fuel mixture in which the compressed air 38 supplied from the second passage 46, the fuel 37a, and the exhaust gas flowing in from the first combustion region are mixed.₂1.0 <λ₂  The ECU 8 (FIG. 1) adjusts so that
[0051]
  By providing two combustion regions (first combustion region 41 and second combustion region 42) in this way, NO is obtained._XCan be purified in the first combustion region 41, and HC, CO, and PM (fine particles such as soot) can be well purified in the second combustion region 42.
[0052]
  Excess air ratio λ in the first combustion region 41₁Λ₁When set to <1.0, a large amount of unburned HC, CO, and PM is produced, but NO_XIs well purified. Further, unburned HC, CO, and PM generated in a large amount in the first combustion region 41 are purified in the second combustion region 42.
[0053]
  FIG. 13 shows NO contained in exhaust gas when the present invention is applied to a diesel engine._XIt is a graph which shows discharge | emission amount of harmful components, such as CO, PM. In the leftmost set of bar graphs, NO in the exhaust gas discharged from the internal combustion engine body 1 is shown._X, CO and PM, and a central set of bar graphs shows NO contained in the exhaust gas purified in the first combustion region 41._X, CO and PM, and a set of bar graphs at the right end is NO contained in the exhaust gas purified in the second combustion region 42._X, CO and PM are shown.
[0054]
  The emission amount of each harmful component shown in the leftmost graph is set to 1 (the emission amount between each harmful component is different, but the harmful component emitted from the internal combustion engine body 1 is set to 1). The emission of each harmful component is shown as a percentage of the graph.
[0055]
  In the central graph, NO among the harmful components contained in the exhaust gas just exiting the internal combustion engine body 1 is NO._XIs purified in the first combustion region 41, and the content is 10% (0.1). Since fuel and compressed air are supplied in the first combustion region 41 and combustion is performed, NO generated at that time_XIncreased by about 5% (0.05). Moreover, CO and PM are increased rather than before being purified in the first combustion region 41.
[0056]
  Next, in the graph at the right end, the amount of CO and PM is reduced to about 10% (0.1) compared with the graph at the left end due to the purification action performed in the second combustion region 42. Recognize. In the second combustion region 42, fuel and compressed air are supplied and combustion is performed._XIncreased by about 5% (0.05). Finally, each harmful component is NO_XIs about 20% of the initial value, and CO and PM are about 10% of the initial value.
[0057]
  Figure4, the excess air ratio λ of the first combustion region (third combustion region) 41₃1.0 <λ₃  The ECU 8 (FIG. 1) adjusts so that In addition, the excess air ratio λ of the second combustion region (fourth combustion region) 42₄1.0 ≦ λ₄Adjust within the range of ≦ 1.2. In this way, mainly HC, CO and PM can be purified in the first combustion region 41, and NO in the second combustion region 42._XCan be purified.
[0058]
  In the first combustion chamber 41, the excess air ratio λ₃Lean (1.0 <λ₃), HC, CO and PM can be purified well, but NO_XThe purification rate is reduced. However, the excess air ratio λ of the second combustion chamber 42₄1.0 ≦ λ₄By setting in the range of ≦ 1.2, NO that was not purified in the first combustion chamber 41_XCan be purified well.
[0059]
  Figure5 isBookOf the combustor 2 of FIG. 1 according to the invention.Another exampleFIG. In FIG. 4, the entire exhaust gas 77 is configured to be supplied to the first combustion region 41, but in FIG. 5, a part of the exhaust gas 77 is transferred to the first combustion region 41 via the bypass passage 78. Without going through, it flows directly into the second combustion region 42. The configuration shown in FIG. 5 is a harmful component (for example, NO) in the exhaust gas._XIt can be applied to exhaust gas having a small content of).
[0060]
  Excess air ratio λ of the first combustion region 41₁Λ₁≦ 1.2 (preferably λ₁<1.0) In the first combustion region 41, mainly NO_XAnd the excess air ratio λ in the second combustion region 42₂1.0 <λ₂  (Preferably 1.4 <λ₂) In the second combustion region 42 mainly purifies HC, CO, etc., or changes the setting of the excess air ratio λ (for example, the excess air ratio λ in the first combustion region 41).₁1.0 <λ₁The excess air ratio λ of the second combustion region 42 is 1.0 ≦ λ₂≦ 1.2), HC and CO are purified in the first combustion region 41 and NO in the second combustion region 42._XYou may make it purify.
[0061]
  FIG.BookOf the combustor 2 of FIG. 1 according to the invention.Another exampleFIG. In FIG. 6, due to the provision of the first bypass passage 47, the dilution gas 34 (part of the exhaust gas 77 or part of the exhaust gas 77 and the compressed air 38) flows into the first combustion region 41 (upstream combustion region) and It can flow directly into the dilution region 43 without passing through the second combustion region 42 (downstream combustion region).
[0062]
  Further, by providing the second bypass passage 48, a part of the exhaust gas 77 or a part of the exhaust gas 77 and the compressed air 38 flows directly into the second combustion region 42 without passing through the first combustion region 41. Be able to.
[0063]
  A secondary fuel supply pipe 44 is provided in the second bypass passage 48, and the fuel 37 a is supplied to the second combustion region 42 through the secondary fuel supply pipe 44.
[0064]
  The harmful components of the exhaust gas 77 flowing into the first combustion chamber 41 from the exhaust gas inlet 74 are combusted by the exhaust gas 77 or the compressed air 38 that flows together with the exhaust gas 77 and the fuel 37 injected from the fuel injection valve 76. After the purification, the exhaust gas 77 flowing in from the second bypass passage 48 or the exhaust gas 77 and the compressed air 38 are mixed in the second combustion region 42 on the downstream side.
[0065]
  The air-fuel mixture is purified in the second combustion region 42, and the exhaust gas purified and heated in the dilution region 43 is diluted with the dilution gas 34, and the temperature is lowered to about 900 ° C., for example.
[0066]
  Excess air ratio λ in the first combustion region 41₁Λ₁≦ 1.2 (preferably λ₁<1.0) and the excess air ratio λ in the second combustion region 42₂1.0 <λ₂  (Preferably 1.4 <λ₂) Is set to NO in the first combustion chamber 41._XIn the second combustion chamber 42, HC, CO, etc. that have not been purified in the first combustion chamber 41 can be purified well.
[0067]
  Conversely, the excess air ratio λ in the first combustion region 41₁1.0 <λ₁  And the excess air ratio λ in the second combustion region 42₂1.0 ≦ λ₂When set to ≦ 1.2, HC, CO and PM are well purified in the first combustion chamber 41, and NO is not purified in the first combustion chamber 41 in the second combustion chamber 42._XCan be purified well.
[0068]
  BookIn the present invention, in order to adjust the amount of the exhaust gas 77 supplied to the first combustion region 41 and the amount of the exhaust gas 77 directly supplied to the second combustion region 42, as already described in the above embodiment, FIG. As shown in FIG. 6, an opening / closing mechanism 52 is provided at the exhaust gas inlet 74.
[0069]
  The opening degree of the exhaust gas inlet 74 is changed by sliding the movable part 53 in the direction indicated by the arrow A, and the amount of the exhaust gas 77 flowing into the first combustion region 41 decreases as the opening degree decreases. The amount of the exhaust gas 77 that flows directly into the second combustion region 42 increases. Conversely, when the opening degree is increased, the inflow amount of the exhaust gas 77 into the first combustion region 41 increases and the inflow amount into the second combustion region 42 decreases.
[0070]
  The opening degree of the opening / closing mechanism 52 and the inflow of the exhaust gas 77 are preliminarily set so that the amount of the exhaust gas 77 that flows into the first combustion region 41 from the exhaust gas intake 74 increases as the amount of harmful components contained in the exhaust gas 77 increases. The quantity relationship is investigated and data is input to the memory of the ECU 8.
[0071]
  For example, the combustion state of the internal combustion engine body 1 (FIG. 1) is determined from the detection signals detected by each sensor (engine speed detection sensor 20, oxygen sensor 22, etc.) and the types of harmful components contained in the exhaust gas 77 The amount is calculated by the ECU 8, and the opening degree of the opening / closing mechanism 52 is adjusted so that the content of harmful components in the exhaust gas after purification is not more than a predetermined amount set in advance.
[0072]
  Figure3, in the configuration of the combustor 2, a part of the exhaust gas 77 flows into the combustion region 31 or the first combustion region 41 from the exhaust gas intake 74, and the rest is the bypass passage 36 (FIG. 3) or the first. It flows into the dilution region 32 or 43 through one bypass passage 47 (FIG. 6).
[0073]
  When the content of harmful components in the exhaust gas 77 is small, as shown in FIG. 3 or FIG. 6, not all of the exhaust gas 77 is purified, but a part of the exhaust gas 77 is used as the dilution gas 34 (FIG. 3). ) Or 43 (FIG. 6). At that time, the exhaust gas other than that used for dilution is burned and purified in the combustion region 31 (FIG. 3) or the first combustion region 41 and the second combustion region 42 (FIG. 6), and then heated to a high temperature (1000 ° C. The combustion gas of the above is mixed with a part of the exhaust gas for dilution in the dilution region 32 (FIG. 3) or 43 (FIG. 6), and the temperature is lowered to about 900 ° C., for example.
[0074]
  In FIG. 6, the excess air ratio λ in the first combustion region 41.₁Λ₁≦ 1.2 (preferably λ₁<1.0) and the excess air ratio λ in the second combustion region 42₂1.0 <λ₂  (Preferably 1.4 <λ₂) Is set to NO in the first combustion chamber 41._XIn the second combustion chamber 42, HC, CO, etc. that have not been purified in the first combustion chamber 41 can be purified well.
[0075]
  Here, for example, the ECU 8 of FIG. 1 sets the amount of the exhaust gas 77 flowing into the dilution regions 32 (FIG. 3) and 43 (FIG. 6) so as not to deteriorate the purification rate more than a preset value. By calculating the combustion state (exhaust gas component) of the internal combustion engine body 1 from the detection signals detected by each sensor (engine speed detection sensor 20, oxygen sensor 22, etc.) and changing the opening of the opening / closing mechanism 52 adjust.
[0076]
  Figure2, 4 and 5, only the compressed air 38 is supplied to the dilution region 32. The compressed air 38 is generated by the compressor 4 connected to the turbine 3 (FIG. 1) driven by the purified exhaust gas and the drive shaft 27.
[0077]
  If it does in this way, an apparatus can be simply comprised only by adding the piping 15 and the metering valve 12 with respect to the turbocharger provided conventionally. Further, the compressed air supplied to the dilution region 32 (43) may be supplied by providing a dedicated compressor (compressor) independently of the compressor 4.
[0078]
  NO_XIn the first combustion region 41, the amount of compressed air 38 supplied from the compressor 4 or a separate dedicated compressor (not shown) is adjusted so that HC and CO can be purified well. Excess air ratio λ₁And the excess air ratio λ in the second combustion region 42₂Set each.
[0079]
  Figure7BookAn internal combustion engine having an exhaust emission control device according to the inventionAnother exampleIt is a systematic diagram. As shown in FIG. 7, a heat exchanger 54 is provided in an exhaust pipe 55 through which exhaust gas discharged from the turbine 3 passes. Further, water is supplied to the heat exchanger 54 through a water supply pipe 57. Other configurations are the same as those shown in FIG.
[0080]
  In the heat exchanger 54, heat exchange is performed between the high-temperature exhaust gas and the low-temperature water, and then the exhaust gas is discharged to the outside through the exhaust pipe 56, and the water becomes steam and becomes a steam supply pipe 58 to the dilution region in the combustor 2. The steam supplied into the combustor 2 lowers the temperature of the purified exhaust gas, and flows into the turbine 3 through the exhaust pipe 25 to drive the turbine 3.
[0081]
  FIG. 15 is a graph showing the thermal efficiency of the internal combustion engine 200 when the excess air ratio is changed and when steam is supplied to the combustor 2 and when the steam is not supplied. As shown in FIG. 15, it can be seen that when steam is supplied, the overall thermal efficiency is improved regardless of the excess air ratio.
[0082]
  By supplying steam to the dilution region in the combustor 2 in this way, the temperature of the purified exhaust gas can be lowered, the gas volume can be increased, and the driving force of the turbine 3 can be increased.
[0083]
  FIG.BookAn internal combustion engine having an exhaust emission control device according to the inventionAnother exampleIt is a systematic diagram. Figure11As shown in FIG. 2, a heat exchanger 70 is provided in the middle of the compressed air supply pipe 15, and an exhaust pipe 26 connected to the turbine 3 is passed through the heat exchanger 70.
[0084]
  The configuration of FIG. 11 is different from the configuration of FIG. 1 in that heat exchange is performed between the low-temperature compressed air and the high-temperature exhaust gas in the heat exchanger 70. All other configurations are the same as those in FIG. If the temperature is raised in advance before the compressed air is supplied to the combustor 2, the amount of fuel consumed to raise the combustion temperature in the combustor 2 can be saved. Therefore, the fuel consumption in the combustor 2 can be reduced while maintaining the purification performance.
[0085]
  Figure9 isBookAn internal combustion engine having an exhaust emission control device according to the inventionAnother exampleIt is a systematic diagram. In the internal combustion engine 400 shown in FIG. 9, a compressor 62 (first compressor) is arranged in series with the compressor 4 in the internal combustion engine 100 of FIG. 1. Power is transmitted from the turbine 3 to the compressor 62 by a drive shaft 63 coaxial with the drive shaft 27 and connected to the compressor 4 (second compressor).
[0086]
  The compressor 62 takes in air through the air intake pipe 13 and sends the taken-in air to the cooler 64 through the pipe 65. Cooling water is supplied from a cooling water supply pipe 67 to the cooler 64 (heat exchanger). The air is cooled by the cooling water in the cooler 64, and the cooled air is sent to the compressor 4 through the pipe 66. The cooling water is discharged outside through the cooling water discharge pipe 68 after cooling the air. The other configuration of the internal combustion engine 400 is the same as that of the internal combustion engine 100 of FIG.
[0087]
  When the internal combustion engine 400 is configured in this manner, the thermal efficiency can be improved by about 2 points (for example, from 40% to 42%) compared to the internal combustion engine 100 of FIG. 1 while maintaining the exhaust gas purification rate.
[0088]
  Figure8 isBookAn internal combustion engine having an exhaust emission control device according to the inventionAnother exampleIt is a systematic diagram. In the internal combustion engine 300 shown in FIG. 8, a turbine 61 is disposed on the downstream side of the turbine 3, and exhaust gas flows into the turbine 61 through the exhaust pipe 26. The generator 61 driven by the drive shaft 18 is connected to the turbine 61. The generator 7 is driven by the turbine 61, and the exhaust gas is discharged from the turbine 61 to the outside through the exhaust pipe 59. Other configurations are the same as those of the internal combustion engine 100 of FIG.
[0089]
  When the internal combustion engine 300 is configured in this way, the turbine 3 can be driven with priority over the turbine 61 when the internal combustion engine 300 is at a low load or is operated at a low speed, and the turbine 3 generates power while maintaining the purification rate. It is possible to start up more quickly than the internal combustion engine 100 of FIG. The turbine 61 operates only when the turbine 3 is fully opened. For example, if the internal combustion engine 300 is driven at 50% of the rating, only the compressor 4 can be driven by the turbine 3 while the turbine 61 is stopped.
[0090]
  Figure10 isBookAn internal combustion engine 500 equipped with an exhaust emission control device according to the inventionAnother exampleIt is a systematic diagram. In the internal combustion engine 500 of FIG. 10, some configurations are further added to the internal combustion engine 300 of FIG. First, a drive shaft 69 is connected to the turbine 61 coaxially with the drive shaft 18. A compressor 62 driven by the turbine 61 via the drive shaft 69 is provided.
[0091]
  The compressor 62 takes in air from the air intake pipe 13 and sends the compressed air to the cooler 64 via the pipe 65. Cooling water is supplied to the cooler 64 via a cooling water supply pipe 67, and the cooling water cools the compressed air in the cooler 64 and is then discharged to the outside from the cooling water discharge pipe 68. The compressed air cooled in the cooler 64 is supplied to the compressor 4 via the pipe 66. The subsequent operation is the same as that of the internal combustion engine 100 of FIG.
[0092]
  Here, the compressor 4 and the compressor 62 are each selected and installed in a combination that can be driven at an optimum rotational speed. By selecting the two compressors 4 and 62 as described above, optimum compression efficiency can be achieved.
[0093]
  The operation of the internal combustion engine can be stabilized, the reliability of the calculation result of the ECU 8 necessary for the purification action in the combustor 2 can be improved, and the reduction of the purification rate can be prevented in advance.
[0094]
  Figure12 isBookOf an internal combustion engine 700 equipped with an exhaust emission control device according to the inventionAnother exampleIt is a systematic diagram. The internal combustion engine 700 is not provided with a supercharger (compressor), and the internal combustion engine 700 is a natural air supply system. Even in a non-supercharged engine such as the internal combustion engine 700 of FIG. 12, the exhaust gas can be purified by the combustor 2 as in the supercharged engine.
[0095]
  Furthermore, when the turbine 3 is arranged downstream of the combustor 2, the generator 7 connected by the drive shaft 18 can be operated, and the thermal efficiency can be improved while maintaining the purification rate.
[0096]
  Figure17Book1 is a schematic cross-sectional view of a combustor 80 provided in an exhaust passage 24 of an internal combustion engine embodying the invention. In the internal combustion engine 100 of FIG. 1, a combustor 80 is installed instead of the combustor 2.WasteIt corresponds to an internal combustion engine equipped with an air purification device. A fuel injection valve for injecting fuel (fuel spray 85) into the inner cylinder 51 is supplied with fuel 37 through the fuel supply pipe 10 at the upstream end of the combustor 80 (upstream in the direction in which the exhaust gas 77 flows). 76 is provided. As shown in FIG. 17, in the combustor 80, the flame holding region in order from the upstream side.81, A combustion region 31 and a dilution region 32 are formed.
[0097]
  One end of a compressed air supply pipe 15 a provided with swirl vanes 35 is connected to the upstream end of the combustor 80. The compressed air supply pipe 15a is connected to the compressed air supply pipe 15 by a pipe (not shown), and the compressed air 38a is supplied into the compressed air supply pipe 15a.
[0098]
  The fuel supply pipe 10 is protected by a protective pipe 75 from an exhaust gas 77 having a high temperature (lower temperature than a combustion gas burned in a combustion region 31 described later). The protective pipe 75 is connected to the compressed air supply pipe 15 by a pipe (not shown), and compressed air (hereinafter referred to as assist air 71) is provided in the protective pipe 75 (that is, the space between the fuel supply pipe 10 and the protective pipe 75). .) Is supplied. As shown in FIG. 17, the combustor side end portion of the protective tube 75 penetrates the end portion of the compressed air supply tube 15 a and is externally fitted to the swirl vane 35.
[0099]
  The fuel injection valve 76, the protective pipe 75, and the compressed air supply pipe 15a are provided to the combustor 80 (inner cylinder 51) so that fuel or air can be injected or discharged into the flame holding region 81 of the combustor 80, respectively. Yes. In addition, a spark plug 30 is provided in the flame holding region 81.
[0100]
  The fuel 37 supplied from the fuel supply pipe 10 is sprayed from the fuel injection valve 76 (hereinafter referred to as fuel spray 85). The assist air 71 flowing in the protective tube 75 is discharged in the vicinity of the fuel spray 85 in the flame holding region 81.
[0101]
  Further, the compressed air in the compressed air supply pipe 15 a flows into the flame holding region 81 as a swirl flow 84 by passing through the swirl vanes 35, and the swirl flow 84 flows between the fuel spray 85 and the assist air 71. Stirring produces a substantially uniform mixture in the flame holding region 81. The air-fuel mixture generated in the flame-holding region 81 is easily ignited because the oxygen concentration is high as much as it does not contain exhaust gas, and is ignited by the spark plug 30 to generate a flame (fire type). This flame moves to the downstream combustion region 31 by the swirling flow 84 discharged continuously.
[0102]
  As shown in FIG. 17, the combustion region 31 is provided with an exhaust gas inlet 82 having swirl vanes 49. Exhaust gas 77 flowing in the exhaust passage 24 passes through the swirl blade 49 from the exhaust gas inlet 82 and flows into the combustion region 31 while swirling. The exhaust gas 77 flowing into the combustion region 31 is burned by the flame supplied from the flame holding region 81, and harmful components (for example, CO, HC or NO)_X) Is purified.
[0103]
  The excess air ratio λ in the combustion region 31 can be arbitrarily set by adjusting the injection amount of the fuel spray 85 and the supply amounts of the compressed air 38a and the assist air 71. <1.0 range), especially NO among harmful components in the exhaust gas 77_XCan be purified well. Further, when the excess air ratio λ in the combustion region 31 is set to be lean (in the range of 1.0 <λ, particularly in the range of 1.4 <λ), particularly CO and HC among the harmful components in the exhaust gas 77 are set. Can be purified well.
[0104]
  Compressed air 38 is supplied to the dilution region 32 provided on the downstream side of the combustion region 31 via the compressed air supply pipe 15, and the compressed air 38 is mixed with the high-temperature combustion gas burned and purified in the combustion region 31. Then, the temperature of the combustion gas is lowered, and the combustion gas whose temperature has been lowered is supplied to a turbine (not shown).
[0105]
  18 is a schematic cross-sectional view of a combustor 90 in which a first combustion region 41 and a second combustion region 42 are provided instead of the combustion region 31 in the combustor 80 shown in FIG. The combustor 90 is provided with an exhaust gas inlet 87 having a swirl vane 86 that allows the exhaust gas 77 to flow into the second combustion region 42, and a secondary fuel supply pipe 44 that supplies the fuel 37 a to the second combustion region 42. It is. The structure of the other combustor 90 is the same as the structure of the combustor 80 of FIG. Compressed air 38 is supplied to the dilution region 43 from the compressed air supply pipe 15.
[0106]
  In the combustor 90, the excess air ratio λ in the first combustion region 41 is set to lean (1.0 <λ and preferably 1.4 <λ), and the excess air in the second combustion region 42 is set. By setting the rate λ to be rich (range λ <1.0), NO in the exhaust gas 77 is reduced._XCO, HC, etc. can be purified well.
[0107]
  FIG.The figure17, 18of4 is a schematic sectional view of a combustor 91 different from the combustors 80 and 90. In the combustor 91, a part of the exhaust gas 77 passes through the swirl vanes 49 and flows into the combustion region 31 to be purified, and the remaining exhaust gas flows into the dilution region 32 from the exhaust gas inlet 87. The temperature of the combustion gas heated in the combustion region 31 is lowered.
[0108]
  The content of harmful components contained in the exhaust gas 77 exhausted from the internal combustion engine is relatively low, and purifying a part of the exhaust gas 77 instead of the total amount reduces the amount of harmful components discharged to an amount that satisfies the environmental standards. 19 can be employed.
[0109]
  FIG.The figure20 is a schematic cross-sectional view of another combustor 92 different from the combustors 80, 90 and 91 of FIGS. 17 to 19. The combustor 92 is provided with a first combustion region 41 and a second combustion region 42 in place of the combustion region 31 in the combustor 91 of FIG. 19, and a secondary fuel supply pipe 44 is provided in the second combustion region 42. Fuel can be supplied. Further, the combustion gas purified in the first combustion region 41 and part of the exhaust gas 77 before purification can flow into the second combustion region 42.
[0110]
  In the combustor 92, the exhaust gas 77 flowing in from the exhaust gas inlet 82 is purified in the first combustion region 41 and NO._XIs reduced and moved to the second combustion region 42 as it is, and then CO and HC components are reduced. Further, the exhaust gas 77 flows into the second combustion region 42 through the swirl vanes 86 provided at the exhaust gas inlet 87, and the CO and HC components are purified.
[0111]
  The combustion gas purified in the second combustion region 42 moves to the dilution region 43, mixes with the exhaust gas 77 flowing in from the exhaust gas inlet 88 and decreases in temperature, and the combustion gas whose temperature has decreased is not shown in the turbine. Supplied to. The amount of harmful components contained in the combustion gas is such that the amount of exhaust gas 77 flowing in from each inflow port (exhaust gas inflow ports 82, 87 and 88) (within each inflow port) so as to be within the permissible range of environmental standards. The passage width of the exhaust gas 77) is set.
[0112]
【The invention's effect】
  In the first aspect of the invention, the combustor 2 is provided in the exhaust passage 24 to purify the exhaust gas. Therefore, the exhaust gas can be purified without using a catalyst or a filter as in the conventional case. Therefore, the initial cost is low compared with the purification method using a catalyst, and the purification performance is not affected by the fuel component (especially the sulfur component). Can also be used, and can be applied to various internal combustion engines used in a wide range of fields.
[0113]
  Since the excess air ratio λ in the combustor 2 can be detected and the detected excess air ratio λ can be set within a desired range, for example, harmful components contained in the exhaust gas are mainly NO. _X If so, the excess air ratio λ can be set to the rich side, and conversely, if a large amount of HC, CO and PM (fine particles such as soot) is contained, the excess air ratio λ can be easily set to the lean side. A good purification rate can be obtained.
[0114]
  ContractClaim2In the present invention, the fuel supply amount adjusting means (ECU 8, metering valve 11, oxygen sensor 22 and the like in FIG. 1) is used as the excess air ratio control means, and the combustion status in the internal combustion engine body 1 is grasped by each sensor. The ECU 8 calculates an amount of fuel that can change the excess air ratio λ in the combustor 2 within a desired range, and adjusts the opening of the metering valve 11 to supply the fuel to the combustor 2. Is provided), the excess air ratio λ in the combustor 2 can be appropriately controlled, and the exhaust gas in the combustor 2 can be purified well.
[0115]
  Claim3In the present invention, the excess air ratio control means is claimed.2In addition to the fuel supply amount adjusting means similar to the above, the air supply amount adjusting means (comprising the ECU 8, the metering valve 12, the compressor 4, the oxygen sensor 22 and the like in FIG. The ECU 8 calculates the amount of air that can be grasped and can change the excess air ratio λ in the current combustor 2 within a desired range, and adjusts the opening of the metering valve 12 to the combustor 2. A mechanism for controlling the amount of air supply)2It is easier to set the excess air ratio λ in the combustor 2 to a desired range, and the exhaust gas can be purified well.
[0116]
  Claim4In the invention of claim3In the present invention, a compressor is provided as an air supply amount adjusting means. This compressor is claimed3As shown in this embodiment, the compressor 4 may also be used. However, if a dedicated compressor is provided separately, all the compressed air supplied from the compressor 4 is supplied to the internal combustion engine body 1. Therefore, it is possible to avoid a reduction in supercharging efficiency to the internal combustion engine body 1.
[0117]
  Claim5In this invention, since the entire amount of the exhaust gas discharged from the internal combustion engine main body 1 is supplied to the combustion region of the combustor 2, the exhaust gas purification rate can be maintained high.
[0118]
  Claim6In the present invention, a part of the exhaust gas discharged from the internal combustion engine body 1 can be directly supplied to the dilution region downstream of the combustion region of the combustor 2, and the supply amount and dilution of the exhaust gas to the combustion region are made possible. Since adjustment means (mechanism constituted by the ECU 8 in FIG. 1, the opening / closing mechanism 52 in FIG. 2, etc.) for adjusting the direct supply amount to the region is provided, the inclusion of harmful components of exhaust gas discharged from the internal combustion engine When the amount is small, the amount of exhaust gas to be purified in the combustion region can be reduced, and the amount of fuel supplied to the combustor 2 can be reduced accordingly.
[0119]
  Claim7In the present invention, the upstream combustion region 41 and the downstream combustion region 42 are provided in the combustor 2, the excess air ratio λ in the upstream combustion region 41 is set to λ ≦ 1.2, and the downstream combustion region 42 Since the excess air ratio λ is set to 1.0 <λ, the upstream combustion region 41 is mainly NO._XIn the downstream combustion region 42, mainly fine particles such as HC, CO, and soot can be purified. Even if the exhaust gas discharged from the internal combustion engine body 1 contains any harmful components, It can be purified well.
[0120]
  Claim8In the present invention, the upstream combustion region 41 and the downstream combustion region 42 are provided in the combustor 2, the excess air ratio λ in the upstream combustion region 41 is set to 1.0 <λ, and the downstream combustion region 42 Since the excess air ratio λ is set to 1.0 ≦ λ ≦ 1.2, the upstream combustion region 41 can mainly purify fine particles such as HC, CO, and soot, and the downstream combustion region 42. Then mainly NO_XThe exhaust gas discharged from the internal combustion engine main body 1 can be purified well even if it contains any harmful components.
[0121]
  Claim9In the invention of claim7By setting the excess air ratio λ of the upstream combustion region 41 in the present invention to λ <1.0,7NO than the invention of_XIn this case, the unburned HC generated in a large amount at that time is purified in the downstream combustion region 42.7As a whole, the exhaust gas purification performance can be improved as compared with the present invention.
[0122]
  Claim10In the invention of claim7-9In the present invention, since the entire amount of exhaust gas supplied to the upstream combustion region 41 is supplied to the downstream combustion region 42, NO_X, HC, CO, and soot can all be finely purified.
[0123]
  Claim11In this invention, the exhaust gas generated in the internal combustion engine body 1 is directly supplied to the upstream combustion region 41 and the downstream combustion region 42, and the exhaust gas purified in the upstream combustion region 41 is supplied to the downstream combustion region 42. Thus, the amount of air supplied from the compressor 4 can be reduced, and the required amount of fuel supplied can be saved.
[0124]
  Claim12In the invention of claim7-9In this invention, since a part of the exhaust gas discharged from the internal combustion engine body 1 is directly supplied to the dilution region 43 provided downstream of the downstream combustion region 42, the amount of air supplied from the compressor 4 Can be reduced, and the required amount of fuel can be reduced.
[0125]
  Claim13In the invention of claim10~12In the present invention, the adjusting means (mechanism constituted by the ECU 8 in FIG. 1, the opening / closing mechanism 52 in FIG. 5, etc.) for adjusting the supply amount of the exhaust gas directly supplied to the upstream combustion region 41 and the downstream combustion region 42, respectively. Since it is provided, the amount of fuel supplied to the combustor 2 can be set while taking into consideration the amount of harmful components contained in the exhaust gas discharged from the internal combustion engine body 1 and avoiding a reduction in the purification rate.
[0126]
  Claim14In the present invention, since a part of the exhaust gas discharged from the internal combustion engine body 1 is directly supplied to the dilution region 43, the purified exhaust gas whose temperature has been raised in the upstream combustion region 41 and the downstream combustion region 42 is obtained. The temperature of the gas can be lowered.
[0127]
  Claim15In this invention, the compressed air generated by the compressor is supplied to the dilution region 43 and the temperature of the exhaust gas in the dilution region 43 is lowered, so that the temperature of the exhaust gas after purification is lowered while maintaining a good purification rate. It can be discharged.
[0128]
  Claim16In the invention of claim15In the present invention, the compressor for supplying the compressed air to the dilution region 43 is also used as the supercharging compressor 4 to simplify the apparatus. In addition, steam is generated in the heat exchanger by high-temperature exhaust gas discharged from the turbine 3 that drives the compressor 4 for supercharging, and this steam is supplied to the dilution region 43 of the combustor 2. The steam is supplied to the turbine 3 together with the exhaust gas, and the thermal efficiency can be improved while maintaining a high purification rate of the exhaust gas. The flow rate of the gas passing through the turbine 3 is increased, and the overall power can be improved.
[0129]
  Claim1-16In any of the inventions, harmful components in the exhaust gas can be purified well not only during the normal operation of the internal combustion engine body 1 but also at the time of start-up and at a low load. Therefore, no matter what operation the internal combustion engine body 1 performs (that is, in the full load region and the full operation range), it is possible to satisfactorily purify harmful components contained in the exhaust gas discharged.
[Brief description of the drawings]
[Figure 1]Book1 is a system schematic diagram showing a fuel supply path, an air supply path, an exhaust gas discharge path, and a signal transmission path of an internal combustion engine equipped with an exhaust emission control device according to the invention.
[Figure 2]Book2 is a schematic cross-sectional view of the combustor of FIG. 1 in accordance with the invention.
[Fig. 3]BookThe combustor of FIG. 1 according to the inventionAnother exampleFIG.
[Fig. 4]BookThe combustor of FIG. 1 according to the inventionAnother exampleFIG.
[Figure 5]Book1 of the combustor of FIG. 1 according to the invention.Another exampleFIG.
[Fig. 6]BookThe combustor of FIG. 1 according to the inventionAnother exampleFIG.
[Fig. 7]BookAn internal combustion engine having an exhaust emission control device according to the inventionAnother exampleIt is a systematic diagram.
[Fig. 8]BookAn internal combustion engine having an exhaust emission control device according to the inventionAnother exampleIt is a systematic diagram.
FIG. 9BookAn internal combustion engine having an exhaust emission control device according to the inventionAnother exampleIt is a systematic diagram.
FIG. 10BookAn internal combustion engine having an exhaust emission control device according to the inventionAnother exampleIt is a systematic diagram.
FIG. 11BookAn internal combustion engine having an exhaust emission control device according to the inventionAnother exampleIt is a systematic diagram.
FIG.BookAn internal combustion engine having an exhaust emission control device according to the inventionAnother exampleIt is a systematic diagram.
FIG. 13 shows NO contained in exhaust gas when the present invention is applied to a diesel engine._XIt is a graph which shows discharge | emission amount of harmful components, such as CO, PM.
FIG. 14 shows NO when the excess air ratio is changed by setting the oxygen concentration in the combustor to less than 10%._XIt is a graph which shows the purification rate.
FIG. 15 is a graph showing the thermal efficiency of the internal combustion engine when the excess air ratio is changed and when steam is supplied to the combustor and when it is not supplied.
FIG. 16 shows combustion temperature in the combustor and CO and NO in the exhaust gas._XIt is a graph which shows the relationship of the tendency of purification.
FIG. 17Book1 is a schematic sectional view of a combustor of an internal combustion engine embodying the invention.
FIG. 18Book18 is a schematic sectional view of a combustor different from that of FIG. 17 of the internal combustion engine in which the invention is implemented.
FIG. 19BookFig. 19 is a schematic sectional view of a combustor different from Figs. 17 and 18 of the internal combustion engine in which the invention is implemented.
FIG. 20Book20 is a schematic cross-sectional view of a combustor different from that of FIGS.
[Explanation of symbols]
1 Internal combustion engine body
2 Combustor
3 Turbine
4 compressors (second and fourth compressors)
5 Intercooler
6,7 generator
8 ECU
9,10 Fuel supply pipe
11,12 Metering valve
19 Supply pressure detection sensor
20 Engine speed detection sensor
21 Exhaust gas flow meter (exhaust gas emission detection means)
22 Oxygen sensor
23 Exhaust temperature sensor
24-26 Exhaust passage
27 Drive shaft
28 Temperature sensor
29 Fuel tank
31 Combustion zone
32 Dilution area
36 Bypass passage
41 1st combustion area (upstream combustion area)
42 Second combustion region (downstream combustion region)
43 Dilution area
49 Swirling blades
50 Combustor cylinder
51 Combustor inner cylinder
52 Opening and closing mechanism
53 Moving parts
54 Heat exchanger
55,56 Exhaust pipe
61 Turbine
62 Compressor (first and third compressors)
63 Drive shaft
64 cooler
70 heat exchanger
71 Assist air
74 Exhaust gas intake
76 Fuel injection valve
80 combustor
81 Flame holding area
82, 83, 87, 88 Exhaust gas inlet
90-92 combustor
100 Internal combustion engine

Claims (16)

In an internal combustion engine equipped with an exhaust purification device, provided with a combustor in an exhaust passage of the internal combustion engine and purifying harmful components contained in exhaust gas by combustion in the combustor,
An excess air ratio control means and a combustion temperature control means for controlling the excess air ratio and the combustion temperature in the combustor are provided;
Excess air in the exhaust gas generated in the combustion chamber of the internal combustion engine from engine speed detection means for detecting the engine speed of the internal combustion engine, exhaust temperature detection means, supply pressure detection means, and detection signals obtained by these detection means An excess air ratio calculating means for calculating the rate and an engine output calculating means for calculating the engine output;
An exhaust gas emission amount detecting means for detecting an exhaust gas amount discharged from the combustion chamber of the internal combustion engine;
The excess air ratio control means can detect the excess air ratio λ in the combustor based on the excess air ratio calculated by the excess air ratio calculation means and the exhaust gas emission amount obtained by the exhaust gas emission amount detection means. An internal combustion engine provided with an exhaust emission control device, wherein the detected excess air ratio λ can be changed within a desired range . A fuel supply amount adjusting means is provided as the excess air ratio control means, and the excess air ratio in the combustor can be controlled by controlling the amount of fuel supplied to the combustor by the fuel supply amount adjusting means. An internal combustion engine provided with the exhaust emission control device described. The internal combustion engine provided with the exhaust emission control device according to claim 1, comprising fuel supply amount adjusting means and air supply amount adjusting means as the excess air ratio control means . The internal combustion engine provided with the exhaust gas purification device according to claim 3 , further comprising a compressed air supply unit using a compressor as the air supply amount adjusting unit . 2. An internal combustion engine comprising the exhaust emission control device according to claim 1 , wherein a total amount of exhaust gas of the internal combustion engine is supplied to a combustion region in the combustor . Adjustment capable of adjusting the amount of exhaust gas supplied to the combustion region for purifying exhaust gas in the combustor and the amount of exhaust gas supplied to the dilution region for reducing the temperature of the purified exhaust gas downstream from the combustion region An internal combustion engine comprising the exhaust emission control device according to claim 1 comprising means . The excess air ratio λ in the combustor
λ ≦ 1.2
An upstream combustion region for purifying NO _x in the exhaust gas is set in the range of
The excess air ratio λ is set downstream of the upstream combustion region.
1.0 <λ
A downstream combustion region for purifying particulates such as HC, CO and soot in the exhaust gas by setting to the range of
Internal combustion engine having an exhaust purifying apparatus according to claim 1 for purifying NO _X, HC, fine particles such as CO and soot contained in the exhaust gas at the upstream combustion region and a downstream combustion region. The excess air ratio λ is set upstream of the combustor.
1.0 <λ
An upstream combustion region for purifying particulates such as HC, CO and soot in the exhaust gas is set in the range of
The excess air ratio λ is set downstream of the upstream combustion region.
1.0 ≦ λ ≦ 1.2
A downstream combustion region for purifying NO _X in the exhaust gas is set in the range of
Internal combustion engine having an exhaust purifying apparatus according to claim 1 for purifying NO _X, HC, fine particles such as CO and soot contained in the exhaust gas at the upstream combustion region and a downstream combustion region. The excess air ratio λ is set upstream of the combustor.
λ <1.0
An upstream combustion region for purifying NO _x in the exhaust gas is set in the range of
The excess air ratio λ is set downstream of the upstream combustion region.
1.4 <λ
A downstream combustion region for purifying particulates such as HC, CO and soot in the exhaust gas by setting to the range of
Internal combustion engine having an exhaust purifying apparatus according to claim 1 for purifying NO _X, HC, fine particles such as CO and soot contained in the exhaust gas at the upstream combustion region and a downstream combustion region. An internal combustion engine comprising the exhaust emission control device according to any one of claims 7 to 9 , wherein the entire amount of exhaust gas supplied to the upstream combustion region of the combustor is supplied to the downstream combustion region . A branch passage for supplying exhaust gas generated in the internal combustion engine to the upstream combustion region and the downstream combustion region of the combustor is provided, and the exhaust gas supplied to the upstream combustion region can be supplied to the downstream combustion region. An internal combustion engine comprising the exhaust emission control device according to any one of claims 7 to 9 . A dilution region for lowering the temperature of the exhaust gas after purification is provided further downstream than the downstream combustion region, and the exhaust gas generated in the internal combustion engine is disposed in the upstream combustion region, the downstream combustion region, and The exhaust emission control device according to any one of claims 7 to 9 , wherein a branch passage for supplying to the dilution region is provided, and exhaust gas purified in the upstream combustion region can be supplied to the downstream combustion region. Internal combustion engine. An internal combustion engine comprising the exhaust emission control device according to any one of claims 10 to 12 , further comprising an adjusting unit that adjusts a supply amount of exhaust gas directly supplied to the upstream combustion region and the downstream combustion region . The exhaust gas generated in the internal combustion engine can be directly supplied to the dilution region downstream of the combustion region in the combustor, and the temperature of the exhaust gas purified in the combustion region is lowered . An internal combustion engine comprising the exhaust emission control device according to any one of the above. The compressed air generated by the compressor can be supplied to the dilution region downstream of the combustion region in the combustor, and the temperature of the exhaust gas purified in the combustion region is lowered . An internal combustion engine comprising any one of the exhaust gas purification apparatuses. The heat exchanger which produces | generates a vapor | steam with the exhaust gas of the said internal combustion engine was provided, and the vapor | steam produced | generated with the said heat exchanger was able to be supplied to the dilution area | region downstream from the fuel area | region in a combustor. An internal combustion engine comprising the exhaust emission control device according to any one of the above.

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