WO2015086905A1 - Engine exhaust gas control system - Google Patents

Engine exhaust gas control system Download PDF

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Publication number
WO2015086905A1
WO2015086905A1 PCT/FI2014/050982 FI2014050982W WO2015086905A1 WO 2015086905 A1 WO2015086905 A1 WO 2015086905A1 FI 2014050982 W FI2014050982 W FI 2014050982W WO 2015086905 A1 WO2015086905 A1 WO 2015086905A1
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WO
WIPO (PCT)
Prior art keywords
exhaust gas
line
engine
heating medium
heat exchanger
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/FI2014/050982
Other languages
French (fr)
Inventor
Antti MELAMIES
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Wartsila Finland Oy
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Wartsila Finland Oy
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Filing date
Publication date
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Publication of WO2015086905A1 publication Critical patent/WO2015086905A1/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
    • F01N3/18—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control
    • F01N3/20—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control specially adapted for catalytic conversion
    • F01N3/2006—Periodically heating or cooling catalytic reactors, e.g. at cold starting or overheating
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02G—HOT GAS OR COMBUSTION-PRODUCT POSITIVE-DISPLACEMENT ENGINE PLANTS; USE OF WASTE HEAT OF COMBUSTION ENGINES; NOT OTHERWISE PROVIDED FOR
    • F02G5/00—Profiting from waste heat of combustion engines, not otherwise provided for
    • F02G5/02—Profiting from waste heat of exhaust gases
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/02—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust
    • F01N3/0205—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust using heat exchangers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
    • F01N3/18—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control
    • F01N3/20—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control specially adapted for catalytic conversion
    • F01N3/206—Adding periodically or continuously substances to exhaust gases for promoting purification, e.g. catalytic material in liquid form, NOx reducing agents
    • F01N3/2066—Selective catalytic reduction [SCR]
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES
    • F01N5/00—Exhaust or silencing apparatus combined or associated with devices profiting by exhaust energy
    • F01N5/02—Exhaust or silencing apparatus combined or associated with devices profiting by exhaust energy the devices using heat
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B30/00—Heat pumps
    • F25B30/02—Heat pumps of the compression type
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES
    • F01N2240/00—Combination or association of two or more different exhaust treating devices, or of at least one such device with an auxiliary device, not covered by indexing codes F01N2230/00 or F01N2250/00, one of the devices being
    • F01N2240/02—Combination or association of two or more different exhaust treating devices, or of at least one such device with an auxiliary device, not covered by indexing codes F01N2230/00 or F01N2250/00, one of the devices being a heat exchanger
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES
    • F01N2590/00—Exhaust or silencing apparatus adapted to particular use, e.g. for military applications, airplanes, submarines
    • F01N2590/10—Exhaust or silencing apparatus adapted to particular use, e.g. for military applications, airplanes, submarines for stationary applications
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B30/00—Energy efficient heating, ventilation or air conditioning [HVAC]
    • Y02B30/52—Heat recovery pumps, i.e. heat pump based systems or units able to transfer the thermal energy from one area of the premises or part of the facilities to a different one, improving the overall efficiency
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/12—Improving ICE efficiencies

Definitions

  • the present invention concerns in general the technical field of internal combustion engine exhaust systems. Especially the invention concerns an en- gine exhaust gas control system for internal combustion reciprocating engine, the system comprising:
  • the exhaust gas line comprises an exhaust gas aftertreatment device for reducing unwanted emissions of the engine.
  • Selective catalytic reduction is a means of converting nitrogen ox- ides, also referred to as NO x with the aid of a catalyst into diatomic nitrogen, N 2 , and water, H 2 O.
  • a gaseous reductant typically anhydrous ammonia, aqueous ammonia or urea, is added to a stream of flue or exhaust gas and is adsorbed onto a catalyst.
  • Carbon dioxide, CO 2 is a reaction product when urea is used as the reductant.
  • Commercial selective catalytic reduction systems are typically found on large utility boilers, industrial boilers, and municipal solid waste boilers and have been shown to reduce NO x by 70-95%. More recent applications include diesel engines, such as those found on large ships, diesel locomotives, gas turbines, and even automobiles.
  • a SCR system needs stable exhaust gas entry temperature to work properly. Also the temperature needs to be between certain limits.
  • Oxidation catalysts have been successfully used for CO reduction purposes.
  • oxidation catalysts for reduction of the unburned hydrocarbons, especially methane, as this has a relatively large greenhouse gas potential.
  • oxidation catalysts can reduce unburned hydrocarbons.
  • gas engines have become more efficient and the combustion leaner, the exhaust temperatures are too low to ensure good and continuous reduction.
  • An objective of the invention is to present a system for reducing the unwanted or harmfull emissions, such as NOx, CO, UHC emissions of an engine by providing a relatively simple system that maintains the necessary conditions for different exhaust gas aftertreatment processes.
  • the objects of the invention are reached by system as defined by the respective independent claims.
  • an engine exhaust gas control system for internal combustion engine the system comprising:
  • an exhaust gas line is provided for leading the engine exhaust gases out, - the exhaust gas line comprises an exhaust gas aftertreatment device for reducing unwanted emissions of the engine,
  • an exhaust gas heat recovery heat exchanger is in the exhaust gas line downstream of the exhaust gas aftertreatment device
  • an exhaust gas heating device is in the exhaust gas line upstream of the ex- haust gas aftertreatment device
  • a heating medium line from the exhaust gas heat recovery heat exchanger to the exhaust gas heating device comprises a compressor for providing heating medium to the exhaust gas heating device
  • a heating medium line from the exhaust gas heating device to the exhaust gas heat recovery heat exchanger comprises an expansion unit to expand and lower the pressure of the heating medium.
  • the system as presented above enables the use of heat at the exhaust gas to be effectively used so that the process conditions for different exhaust gas aftertreatment devices can be maintained at a proper level. This also ena- bles the location to the exhaust gas aftertreatment system to be located at a position more remote to the engine where the exhaust gas temperature is otherwise already decreased. Without the present system the heat delivered by the exhaust gas would not necessary be high enough to ensure the proper high temperature for aftertreatment and furthermore the energy of heat would be wasted if not recovered for some other purpose.
  • FIG. 1 it is presented an engine 1 exhaust gas control system for inter- nal combustion engine 1 , the system comprising:
  • an exhaust gas line 2 is provided for leading the engine 1 exhaust gases out
  • the exhaust gas line 2 comprises an exhaust gas aftertreatment device 3 for reducing unwanted emissions of the engine 1 ,
  • an exhaust gas heat recovery heat exchanger 4 is in the exhaust gas line 2 downstream of the exhaust gas aftertreatment device 3,
  • an exhaust gas heating device 5 is in the exhaust gas line 2 upstream of the exhaust gas aftertreatment device 3,
  • a heating medium line 45 from the exhaust gas heat recovery heat exchanger 4 to the exhaust gas heating device comprises 5 a compressor 43 for providing heating medium to the exhaust gas heating device 5,
  • the exhaust gas aftertreatment device 3 is a device utilizing a process or processes for reducing unwanted emissions such as NO x , unburned fractions of the fuel (or unburned hydrocarbons UHC) such as methane (CH 4 ) or carbon oxide CO.
  • the exhaust gas aftertreatment device 3 can be for example a selective catalytic reduction device or a methane oxidation catalyst device. These are both examples of reduction processes which require rather high operating temperature and there is a possibility that the exhaust gas temperature is not high enough to ensure the catalytic process to be performed as designed.
  • the Selective Catalytic Reduction -process requires exhaust gas temperature of about 300 °C to perform effectively.
  • the minimum operating temperature for SCR in general is 300 Q C and for bio fuels 340 Q C.
  • Higher sulphur content of the fuel requires a higher operating temperature.
  • a sulphur content of 2% in the fuel requires an exhaust gas temperature of 350 Q C.
  • the methane oxidation catalyst requires the minimum temperature ranges:
  • Fig. 1 there is an exhaust gas heat recovery heat exchanger 4 is in the exhaust gas line 2 downstream of the exhaust gas aftertreatment device 3.
  • the function of the exhaust gas heat recovery heat exchanger 4 is to take heat out of exhaust gas.
  • Exhaust gas temperature is dependent on several factors of the engine and the used fuel.
  • a turbocharger is utilizing energy of high pressure, velocity and temperature of exhaust gas. After the turbo- charger the parameters above have decreased but still the exhaust gas is contains plenty of thermal energy.
  • the exhaust gas heat recovery heat exchanger 4 is configured to recover heat from the exhaust gas (primary flow) and exchange it to a medium of a secondary flow.
  • the heated medium is trans- ported through a heating medium line 45 to a compressor 43 where the medium is further compressed and where the temperature of the medium raises still more.
  • the temperature of the medium is higher than the temperature of the exhaust gas before the exhaust gas heating device 5.
  • the heat is exchanged back to the exhaust gas and the medium is cooling correspondingly.
  • the cooled medium is led through a heating medium line 54 to expansion unit 53 where the pressure of the medium is lowered such that the temperature of the medium decreases below the exhaust gas temperature after the exhaust gas aftertreatment device 3.
  • expansion unit 53 where the pressure of the medium is lowered such that the temperature of the medium decreases below the exhaust gas temperature after the exhaust gas aftertreatment device 3.
  • the compressor 43 of the system needs to fulfill certain criteria to be suitable for the purpose. First of all it needs to be able to compress the medium at relatively high temperatures of up to about 700 °C. According to one embodiment the compressor 43 is steam driven. According to an other embod- iment the compressor 43 is an absorption heat pump. Still more, according to an embodiment the compressor 43 is mechanically or electrically driven. The selection of the compressor 43 type is not dependent of the selected exhaust gas aftertreatment device 2 and can be used with both the Selective Catalytic Reduction device and the Methane Oxidation Catalyst device. [015] As evident to those skilled in the art, the invention and its embodiments are not limited to the above-described embodiment examples.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Combustion & Propulsion (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Health & Medical Sciences (AREA)
  • Toxicology (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Exhaust Gas After Treatment (AREA)

Abstract

An engine (1) exhaust gas control system for internal combustion engine (1), the system comprising: - an exhaust gas line (2) is provided for leading the engine (1) exhaust gases out, - the exhaust gas line (2) comprises an exhaust gas aftertreatment device (3) for reducing unwanted emissions of the engine (1), - an exhaust gas heat recovery heat exchanger (4) is in the exhaust gas line (2) downstream of the exhaust gas aftertreatment device (3), - an exhaust gas heating device (5) is in the exhaust gas line (2) upstream of the exhaust gas aftertreatment device (3), - a heating medium line (45) from the exhaust gas heat recovery heat exchanger (4) to the exhaust gas heat- ing device comprises (5) a compressor (43) for providing heating medium to the exhaust gas heating device (5), - a heating medium line (54) from the exhaust gas heating device (5) to the exhaust gas heat recovery heat exchanger (4) comprises an expansion unit (53) to expand and lower the pressure of the heating medium.

Description

Engine exhaust gas control system
TECHNICAL FIELD
[001 ] The present invention concerns in general the technical field of internal combustion engine exhaust systems. Especially the invention concerns an en- gine exhaust gas control system for internal combustion reciprocating engine, the system comprising:
- an exhaust gas line is provided for leading the engine exhaust gases out,
- the exhaust gas line comprises an exhaust gas aftertreatment device for reducing unwanted emissions of the engine. BACKGROUND OF THE INVENTION
[002] In modern internal combustion piston engines the burning process is well under control, but the high burning temperature causes part of the nitrogen of the intake air to convert in to NOx and there may also be in exhaust gas other unwanted substances such as unburned fractions of the fuel (or unburned hy- drocarbons UHC) such as methane (CH4). For the purpose of reducing unwanted substances and converting those in to less harmful substances there are different exhaust gas aftertreatment devices, which utilize different catalytic processes for said purpose.
[003] Selective catalytic reduction (SCR) is a means of converting nitrogen ox- ides, also referred to as NOx with the aid of a catalyst into diatomic nitrogen, N2, and water, H2O. A gaseous reductant, typically anhydrous ammonia, aqueous ammonia or urea, is added to a stream of flue or exhaust gas and is adsorbed onto a catalyst. Carbon dioxide, CO2 is a reaction product when urea is used as the reductant. Commercial selective catalytic reduction systems are typically found on large utility boilers, industrial boilers, and municipal solid waste boilers and have been shown to reduce NOx by 70-95%. More recent applications include diesel engines, such as those found on large ships, diesel locomotives, gas turbines, and even automobiles. A SCR system needs stable exhaust gas entry temperature to work properly. Also the temperature needs to be between certain limits.
[004] Different new technologies within the engine technology have resulted in a significant rise in engine overall performance and efficiency. At the same time the emissions are decreased and thus the engine causes less pollution. If gas turbines and reciprocating gas engines are compared, the reciprocating engines may still have relatively higher content of unburned hydrocarbons (UHC) in the exhaust. There are some reasons for this, it is mainly due to the non-continuous combustion in reciprocating engines, but other reasons are crevices in the combustion chamber, cold walls, and a possible carry over from intake valve to exhaust valve during scavenging. [005] By improvement of combustion chamber design this emission has been reduced. But as the combustion process is non-continuous in the engine there will be a limit how low it is possible to go with the emissions. Aftertreatment of the flue gasses is necessary for this. Oxidation catalysts have been successfully used for CO reduction purposes. Within the field of exhaust gas after- treatment systems a number of tests have also been carried out for using oxidation catalysts for reduction of the unburned hydrocarbons, especially methane, as this has a relatively large greenhouse gas potential. Earlier tests have shown that oxidation catalysts can reduce unburned hydrocarbons. However, as gas engines have become more efficient and the combustion leaner, the exhaust temperatures are too low to ensure good and continuous reduction.
[006] From the state of the art it is known WO 2006/031910 A2 -publication which discloses an emissions control system that utilizes otherwise wasted heat to efficiently reduce emissions in a main exhaust flow. Heat stored in ex- haust from an auxiliary generator (i.e., auxiliary exhaust) may be used to convert urea to ammonia used by a Selective Catalytic Reducer (SCR) system, and/or the auxiliary exhaust may be used to heat the main exhaust flow before entry into an SCR. Additionally, a heat exchanger may be used to transfer heat from a hot clean flow out of the SCR, to the main exhaust flow entering the SCR. The publication explains that previously, mobile emissions control systems have not used SCR systems to reduce NOx because of the cost and space required for heater fuel. The efficient use of otherwise wasted heat reduces fuel cost and fuel storage requirements, and thereby makes an SCR systems feasible for use in mobile emissions control systems. SUMMARY OF THE INVENTION
[007] An objective of the invention is to present a system for reducing the unwanted or harmfull emissions, such as NOx, CO, UHC emissions of an engine by providing a relatively simple system that maintains the necessary conditions for different exhaust gas aftertreatment processes. [008] The objects of the invention are reached by system as defined by the respective independent claims. In more detail it is an engine exhaust gas control system for internal combustion engine, the system comprising:
- an exhaust gas line is provided for leading the engine exhaust gases out, - the exhaust gas line comprises an exhaust gas aftertreatment device for reducing unwanted emissions of the engine,
- an exhaust gas heat recovery heat exchanger is in the exhaust gas line downstream of the exhaust gas aftertreatment device,
- an exhaust gas heating device is in the exhaust gas line upstream of the ex- haust gas aftertreatment device,
- a heating medium line from the exhaust gas heat recovery heat exchanger to the exhaust gas heating device comprises a compressor for providing heating medium to the exhaust gas heating device,
- a heating medium line from the exhaust gas heating device to the exhaust gas heat recovery heat exchanger comprises an expansion unit to expand and lower the pressure of the heating medium.
[009] The system as presented above enables the use of heat at the exhaust gas to be effectively used so that the process conditions for different exhaust gas aftertreatment devices can be maintained at a proper level. This also ena- bles the location to the exhaust gas aftertreatment system to be located at a position more remote to the engine where the exhaust gas temperature is otherwise already decreased. Without the present system the heat delivered by the exhaust gas would not necessary be high enough to ensure the proper high temperature for aftertreatment and furthermore the energy of heat would be wasted if not recovered for some other purpose.
BRIEF DESCRIPTION OF THE DRAWINGS
[010] In figure 1 it is presented a schematic view of the present system. DETAILLED DESCRIPTION
[01 1 ] In Fig. 1 it is presented an engine 1 exhaust gas control system for inter- nal combustion engine 1 , the system comprising:
- an exhaust gas line 2 is provided for leading the engine 1 exhaust gases out,
- the exhaust gas line 2 comprises an exhaust gas aftertreatment device 3 for reducing unwanted emissions of the engine 1 ,
- an exhaust gas heat recovery heat exchanger 4 is in the exhaust gas line 2 downstream of the exhaust gas aftertreatment device 3,
- an exhaust gas heating device 5 is in the exhaust gas line 2 upstream of the exhaust gas aftertreatment device 3,
- a heating medium line 45 from the exhaust gas heat recovery heat exchanger 4 to the exhaust gas heating device comprises 5 a compressor 43 for providing heating medium to the exhaust gas heating device 5,
- a heating medium line 54 from the exhaust gas heating device 5 to the exhaust gas heat recovery heat exchanger 4 comprises an expansion unit 53 to expand and lower the pressure of the heating medium. In Fig. 1 the exhaust gas aftertreatment device 3 is a device utilizing a process or processes for reducing unwanted emissions such as NOx, unburned fractions of the fuel (or unburned hydrocarbons UHC) such as methane (CH4) or carbon oxide CO. The exhaust gas aftertreatment device 3 can be for example a selective catalytic reduction device or a methane oxidation catalyst device. These are both examples of reduction processes which require rather high operating temperature and there is a possibility that the exhaust gas temperature is not high enough to ensure the catalytic process to be performed as designed. For example, the Selective Catalytic Reduction -process requires exhaust gas temperature of about 300 °C to perform effectively. In more detail, the minimum operating temperature for SCR in general is 300 QC and for bio fuels 340 QC. Higher sulphur content of the fuel requires a higher operating temperature. For instance a sulphur content of 2% in the fuel requires an exhaust gas temperature of 350QC. As an other example, the methane oxidation catalyst requires the minimum temperature ranges:
a) catalytic 500-600°C and
b) non-catalytic 800-900°C to perform effectively.
[012] In Fig. 1 there is an exhaust gas heat recovery heat exchanger 4 is in the exhaust gas line 2 downstream of the exhaust gas aftertreatment device 3. The function of the exhaust gas heat recovery heat exchanger 4 is to take heat out of exhaust gas. Exhaust gas temperature is dependent on several factors of the engine and the used fuel. For example a turbocharger is utilizing energy of high pressure, velocity and temperature of exhaust gas. After the turbo- charger the parameters above have decreased but still the exhaust gas is contains plenty of thermal energy. The exhaust gas heat recovery heat exchanger 4 is configured to recover heat from the exhaust gas (primary flow) and exchange it to a medium of a secondary flow. Then the heated medium is trans- ported through a heating medium line 45 to a compressor 43 where the medium is further compressed and where the temperature of the medium raises still more. After the compressor the temperature of the medium is higher than the temperature of the exhaust gas before the exhaust gas heating device 5. In the exhaust gas heating device 5 the heat is exchanged back to the exhaust gas and the medium is cooling correspondingly.
[013] The cooled medium is led through a heating medium line 54 to expansion unit 53 where the pressure of the medium is lowered such that the temperature of the medium decreases below the exhaust gas temperature after the exhaust gas aftertreatment device 3. Thus the circuit explained above transfers heat from the downstream side of the exhaust gas aftertreatment device 2 to the upstream side of the exhaust gas aftertreatment device 2. This causes the exhaust gas temperature to increase before entering to the exhaust gas aftertreatment device 3 and cooling at the downstream end of the exhaust gas line 2.
[014] The compressor 43 of the system needs to fulfill certain criteria to be suitable for the purpose. First of all it needs to be able to compress the medium at relatively high temperatures of up to about 700 °C. According to one embodiment the compressor 43 is steam driven. According to an other embod- iment the compressor 43 is an absorption heat pump. Still more, according to an embodiment the compressor 43 is mechanically or electrically driven. The selection of the compressor 43 type is not dependent of the selected exhaust gas aftertreatment device 2 and can be used with both the Selective Catalytic Reduction device and the Methane Oxidation Catalyst device. [015] As evident to those skilled in the art, the invention and its embodiments are not limited to the above-described embodiment examples. Expressions representing the existence of characteristics, such as "the system comprising an exhaust gas line", are non-restrictive such that the description of characteristics does not exclude or prerequisite the existence of such other characteris- tics which are not presented in the independent or dependent claims. The reference signs in the figures:
1 engine
2 exhaust gas line
3 exhaust gas aftertreatment device
4 exhaust gas heat recovery heat exchanger
43 compressor
45 heating medium line
5 exhaust gas heating device
53 expansion unit
54 heating medium line

Claims

Claims
1 . An engine (1 ) exhaust gas control system for internal combustion engine (1 ), the system comprising:
- an exhaust gas line (2) is provided for leading the engine (1 ) exhaust gases out,
- the exhaust gas line (2) comprises an exhaust gas aftertreatment device (3) for reducing unwanted emissions of the engine (1 ),
characterized in that
- an exhaust gas heat recovery heat exchanger (4) is in the exhaust gas line (2) downstream of the exhaust gas aftertreatment device (3),
- an exhaust gas heating device (5) is in the exhaust gas line (2) upstream of the exhaust gas aftertreatment device (3),
- a heating medium line (45) from the exhaust gas heat recovery heat exchanger (4) to the exhaust gas heating device (5) comprises a compressor (43) for providing heating medium to the exhaust gas heating device (5),
- a heating medium line (54) from the exhaust gas heating device (5) to the exhaust gas heat recovery heat exchanger (4) comprises an expansion unit (53) to expand and lower the pressure of the heating medium.
2. System according to patent claim 1 , characterized in that the exhaust gas aftertreatment device (3) is a selective catalytic reduction device.
3. System according to patent claim 1 , characterized in that the exhaust gas aftertreatment device (3) is a methane oxidation catalyst device.
4. System according to patent claim 1 , characterized in that the compressor (43) is steam driven.
5. System according to patent claim 1 , characterized in that the compressor (43) is an absorption heat pump.
6. System according to patent claim 1 , characterized in that the compressor (43) is mechanically or electrically driven.
PCT/FI2014/050982 2013-12-11 2014-12-10 Engine exhaust gas control system Ceased WO2015086905A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FI20136246 2013-12-11
FI20136246A FI20136246A7 (en) 2013-12-11 2013-12-11 Engine exhaust gas control system

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WO (1) WO2015086905A1 (en)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20150247437A1 (en) * 2014-02-28 2015-09-03 Cummins Inc. SYSTEMS AND METHODS FOR NOx REDUCTION AND AFTERTREATMENT CONTROL USING PASSIVE NOx ADSORPTION
US9441520B2 (en) 2012-05-21 2016-09-13 Cummins Emission Solutions Inc. Aftertreatment system having two SCR catalysts
US9567888B2 (en) 2014-03-27 2017-02-14 Cummins Inc. Systems and methods to reduce reductant consumption in exhaust aftertreament systems
US9677439B2 (en) 2014-01-20 2017-06-13 Cummins Inc. Systems and methods to mitigate NOx and HC emissions
ITUA20163109A1 (en) * 2016-05-03 2017-11-03 Fpt Motorenforschung Ag THERMAL MANAGEMENT SYSTEM OF A POST-TREATMENT SYSTEM OF EXHAUSTED GAS (ATS)
CN108843431A (en) * 2018-07-25 2018-11-20 中国船舶重工集团柴油机有限公司 Exhaust afterheat utilization system and method based on marine low-pressure SCR
US20180363526A1 (en) * 2015-12-14 2018-12-20 Volvo Truck Corporation An internal combustion engine system and an exhaust treatment unit for such a system
US12428982B1 (en) 2024-05-23 2025-09-30 Ford Global Technologies, Llc Methods and systems for an exhaust system
US12535026B2 (en) 2024-05-23 2026-01-27 Ford Global Technologies, Llc Methods and systems for an exhaust system

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060053775A1 (en) * 2004-09-14 2006-03-16 Powell John G High thermal efficiency selective catalytic reduction (SCR) system
US20060213197A1 (en) * 2005-03-28 2006-09-28 Sal Caro Air pollution control system for ocean-going vessels
US20080223019A1 (en) * 2007-03-14 2008-09-18 Gonze Eugene V Scr cold start heating system for a diesel exhaust
DE102011116227A1 (en) * 2011-10-17 2013-04-18 Scania Cv Ab Exhaust gas treatment device for vehicle, particularly for reducing nitrogen oxide in exhaust gas of vehicle, has exhaust line for supplying liquid reducing agent, where surface is heated up in exhaust pipe

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060053775A1 (en) * 2004-09-14 2006-03-16 Powell John G High thermal efficiency selective catalytic reduction (SCR) system
WO2006031910A2 (en) 2004-09-14 2006-03-23 Advanced Cleanup Technologies, Inc. High thermal efficiency selective catalytic reduction (scr)
US20060213197A1 (en) * 2005-03-28 2006-09-28 Sal Caro Air pollution control system for ocean-going vessels
US20080223019A1 (en) * 2007-03-14 2008-09-18 Gonze Eugene V Scr cold start heating system for a diesel exhaust
DE102011116227A1 (en) * 2011-10-17 2013-04-18 Scania Cv Ab Exhaust gas treatment device for vehicle, particularly for reducing nitrogen oxide in exhaust gas of vehicle, has exhaust line for supplying liquid reducing agent, where surface is heated up in exhaust pipe

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9441520B2 (en) 2012-05-21 2016-09-13 Cummins Emission Solutions Inc. Aftertreatment system having two SCR catalysts
US9677439B2 (en) 2014-01-20 2017-06-13 Cummins Inc. Systems and methods to mitigate NOx and HC emissions
US9512761B2 (en) * 2014-02-28 2016-12-06 Cummins Inc. Systems and methods for NOx reduction and aftertreatment control using passive NOx adsorption
US20150247437A1 (en) * 2014-02-28 2015-09-03 Cummins Inc. SYSTEMS AND METHODS FOR NOx REDUCTION AND AFTERTREATMENT CONTROL USING PASSIVE NOx ADSORPTION
US10113465B2 (en) 2014-03-27 2018-10-30 Cummins Inc. Systems and methods to reduce reductant consumption in exhaust aftertreatment systems
US9567888B2 (en) 2014-03-27 2017-02-14 Cummins Inc. Systems and methods to reduce reductant consumption in exhaust aftertreament systems
US20180363526A1 (en) * 2015-12-14 2018-12-20 Volvo Truck Corporation An internal combustion engine system and an exhaust treatment unit for such a system
US10774712B2 (en) * 2015-12-14 2020-09-15 Volvo Truck Corporation Internal combustion engine system and an exhaust treatment unit for such a system
ITUA20163109A1 (en) * 2016-05-03 2017-11-03 Fpt Motorenforschung Ag THERMAL MANAGEMENT SYSTEM OF A POST-TREATMENT SYSTEM OF EXHAUSTED GAS (ATS)
CN108843431A (en) * 2018-07-25 2018-11-20 中国船舶重工集团柴油机有限公司 Exhaust afterheat utilization system and method based on marine low-pressure SCR
CN108843431B (en) * 2018-07-25 2023-08-18 中船发动机有限公司 Exhaust waste heat utilization system and method based on marine low-voltage SCR
US12428982B1 (en) 2024-05-23 2025-09-30 Ford Global Technologies, Llc Methods and systems for an exhaust system
US12535026B2 (en) 2024-05-23 2026-01-27 Ford Global Technologies, Llc Methods and systems for an exhaust system

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