Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D21/00—Controlling engines characterised by their being supplied with non-airborne oxygen or other non-fuel gas
  • F02D21/06—Controlling engines characterised by their being supplied with non-airborne oxygen or other non-fuel gas peculiar to engines having other non-fuel gas added to combustion air
  • F02D21/08—Controlling engines characterised by their being supplied with non-airborne oxygen or other non-fuel gas peculiar to engines having other non-fuel gas added to combustion air the other gas being the exhaust gas of engine
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
  • F02M26/13—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories
  • F02M26/14—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories in relation to the exhaust system
  • F02M26/15—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories in relation to the exhaust system in relation to engine exhaust purifying apparatus
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
  • F02B3/00—Engines characterised by air compression and subsequent fuel addition
  • F02B3/06—Engines characterised by air compression and subsequent fuel addition with compression ignition

Definitions

• the present invention relates to a method for reducing nitric oxi emissions in the exhaust gases from diesel engines by means of co ducting water into the engine and by recirculating the exhaust gases.
• a drawback in the use of combustion engines such- as diesel engin arises in the form of harmful compounds contained:; in- exhaust gase Among them , the most dangerous and the most difficult o eliminate, a nitric oxides.
• the amount of created nitric, oxides is .cosraparabte.to th temperature prevailing in the combustion, chamber ,-- as,' ell- as. to th oxygen content of the explosion gas.
• the water addition can be carrie out in various ways : according to the DE Patent Application No. 31 4 472 , water is sprayed separately into the combustion chamber. In con nection to the water addition , the water condensed from the exhaus gases can also be utilized; this water is conducted into the combustio chamber by means of spraying , as is the case with water additions i the apparatus introduced in the DE Patent Application No. 28 51 232 The supplied water is fed directly into the suction duct (DE Paten Application No.
• the water is first dispersed in a fine form by feeding the fresh combustion air through a liquid volume an further into the suction duct (DE Patent Applications No. 26 01 45 and 26 33 639) .
• the water to be conducted into the combustion cham ber can also be first evaporated by means of a thermal exchanger, s that the heating is carried out by conducting the hot exhaust gase through a water container.
• the resulting steam is then conducted int the suction duct, whereas the exhaust gases are discharged into th open air.
• the evaporation method is introduced for instance in the S Patent Publication No. 428 587 and DE Patent Applications No. 21 5 755 and 26 04 050. / 86/00094
• Another prior art method for diminishing the nitric oxide emissions of a diesel engine is partial recirculation of the exhaust gases.
• the ex ⁇ haust gas is recirculated back into the engine in dry form.
• the recir ⁇ culated exhaust gas the quantity whereof is advantageously 20% of the suction air volume, functions as an inert gas and thus reduces the oxygen content of the gas contained in the combustion chamber. Simul ⁇ taneously the production of nitric oxide is also diminished .
• the regulation of recirculated exhaust gases is also difficult to control .
• it is preferable that the recirculated exhaust gases are cooled off for instance in order to reduce thermal strain.
• the method of recirculating damp exhaust gases is utilized in the fuel evaporator according to the US Patent No. 2 430 852. In that case, however, the recirculated damp exhaust gases are fed, together with the gasified fuel , into the suction space of a combustion engine. Con ⁇ sequently , the suggested arrangement cannot be applied for instance for diesel engines, where the fuel is sprayed into the combustion chamber.
• the object of the present invention is to eliminate some of the draw backs of the prior art and to realize an improved , more secure metho for reducing the nitric oxide emissions of diesel engine exhaust gases by means of applying the recirculation of cooled exhaust gase combined to the aqueous vapours resulting from the wet cleaning o the exhaust gases.
• the essential novel features of the invention ar apparent from the appended patent claim 1 .
• the exhaust gases from the engine ar conducted through a catalyzer, advantageously for reducing th amount of carbon monoxide and hydrocarbons , before directing th gases into the wet cleaner.
• the exhaust gases ar simultaneuously washed and cooled .
• the cooled exhaust gases are fur ther conducted , humidified by the vapours created in the washing , back into the suction duct of the diesel engine.
• the recirculated ex haust gas the quantity whereof is about 20% of the whole exhaust ga volume , is mixed in the general suction air flow by means of a mixe valve and a nozzle, whereby the mixture ratio can be maintained con stant irrespective of the charge and the speed of rotation .
• the recirculation of the exhaust gases , the cooling of the recirculated exhaust gases , and th water additions into the combustion chamber , as wel l as the regulation of the volume of the returned gas, can thus all be combined.
• Figure 1 is a schematical illustration of a preferred embodiment of the invention
• Figure 2 illustrates the superiority of the damp recirculation method of the invention , as compared to the prior art dry recirculation method.
• the exhaust gases from the diesel engine 1 are conducted , through the catalyzer 2 , into the wet cleaner 3.
• the exhaust gases are cooled and washed .
• the major part of the exhaust gases are discharged through the exhaust pipe 4.
• damp exhaust gas to be recirculated according to the invention is con ⁇ ducted, through the return pipe 5, into the suction system 10 of the diesel engine.
• the recirculated exhaust gas supplied from the return pipe 5 which gas is humidified by the steam created in the cleaner 3, is conducted, via the recirculation valve 6, back to the recirculation nozzle 7.
• the suction air of the diesel engine, drawn in through the air purifier 8 is also conducted to the nozzle.7.
• The. mixture of recir ⁇ culated exhaust gas and pure suction air thus created - tn the nozzle 7 is further conducted , via the suction duct TO? of the-:- diesel- engine into the combustion chamber 9, wherefro " the created?

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Exhaust-Gas Circulating Devices (AREA)
• Output Control And Ontrol Of Special Type Engine (AREA)
• Treating Waste Gases (AREA)

Applications Claiming Priority (1)

Publications (2)

Family

ID=8556404

Family Applications (1)

Country Status (6)

Cited By (1)

Families Citing this family (4)

Family Cites Families (5)

• 1985
  • 1985-03-12 FI FI850966A patent/FI73297C/fi not_active IP Right Cessation
• 1986
  • 1986-09-08 EP EP86905301A patent/EP0280678B1/de not_active Expired - Lifetime
  • 1986-09-08 WO PCT/FI1986/000094 patent/WO1988001016A1/en active IP Right Grant
  • 1986-09-08 DE DE8686905301T patent/DE3668665D1/de not_active Expired - Fee Related
  • 1986-09-08 JP JP86505140A patent/JPH01500765A/ja active Pending
• 1988
  • 1988-05-06 RU SU884355739A patent/RU1839695C/ru active

Non-Patent Citations (1)

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