JP2019044773A - Combustion engine system - Google Patents

Abstract

To remove soot by using a system that is efficient and/or uses a small number of materials.SOLUTION: A combustion engine system includes: an internal combustion engine that generates exhaust gas including soot; a turbocharger driven by the exhaust gas; and an NOreduction unit 4 disposed upstream of the turbocharger and purifying the exhaust gas. The NOreduction unit having soot accumulated therein includes: a catalyst reactor housing 5 having a chamber 6, an inlet pipe 7 and an outlet pipe 8; and one or a plurality of catalyst elements 9 disposed in the chamber. The combustion engine system further includes a soot removal unit 10. The soot removal unit includes: a valve 11 for releasing at least a part of the exhaust gas in the catalyst reactor housing into the soot removal unit; a receiver 14 having a receiver inlet 15 and a ventilation port 16; and a conduit 17 for fluid-connecting the receiver inlet with the valve.SELECTED DRAWING: Figure 2

Description

The present invention includes a combustion engine system, and to a smoke reducing method for reducing the soot in the chamber of the NO _X reduction unit in the combustion engine system according to the present invention.

Exhaust gas from an internal combustion engine is purified by the catalytic reactor to reduce NO _X emissions. During the purification process, soot deposits in the reactor housing and on the surface of the catalytic element in the SCR reactor. In order to clean the soot from these surfaces, high pressure air is injected at predetermined intervals to loosen the soot, and this gas carries the loose soot out of the reactor housing. However, high pressure air is not very efficient at loosening soot and requires a large amount of equipment, ie high pressure pipes and nozzles, which can be costly and difficult to repair or replace. U.S. Pat. No. 5,958,015 discloses an arrangement for removing particulates in a gas stream that is applied to clean the exhaust gas from an internal combustion engine.

WO2006 / 091136

  The object of the present invention is therefore to completely or partly eliminate the above-mentioned disadvantages and drawbacks of the prior art. More particularly, it is an object of the present invention to provide an improved combustion engine system which is more efficient in smoke removal and / or requires less equipment.

The above objective is achieved by the solution described in the present invention by a combustion engine system, together with numerous other objects, advantages and features which will be apparent from the following description. This combustion engine system is
An internal combustion engine that generates an exhaust gas including soot and smoke;
A turbocharger driven by exhaust gas;
Arranged upstream of the turbocharger, a NO _X reduction unit which is fluidly connected to the internal combustion engine for purifying exhaust gases from an internal combustion engine, NO _X reduction units soot is deposited internally,
Chamber, the inlet pipe, and comprises one or more catalyst elements disposed in a chamber of the catalytic reactor housing between the catalyst reactor housing and the inlet pipe and the outlet pipe, having an outlet pipe, NO _X reduction unit And The combustion engine system is
A smoke removal unit,
A valve in fluid communication with the opening of the catalytic reactor housing, the valve having an open position that allows at least a portion of the exhaust gas in the catalytic reactor housing to escape into the soot removal unit;
A receiver having a cross-sectional receiver area and a receiver inlet and vent port;
And a conduit for fluidly coupling the receiver inlet to the valve and having a cross-sectional conduit area smaller than the cross-sectional receiver area.

  By fluidly connecting the receiver inlet to the valve and having a conduit having a cross-sectional conduit area smaller than the cross-sectional receiver area, an acoustic wave is generated within the catalytic reactor housing to loosen at least a portion of the soot.

  An opening may be disposed in the chamber upstream of the one or more catalytic elements.

  Furthermore, the opening may be located in the chamber closer to the inlet pipe than in the middle part of the chamber. By positioning the opening closer to the inlet pipe than the middle portion of the chamber, a backflow is generated in the chamber to loosen soot.

  Also, the opening may be located in the chamber closer to the outlet pipe than the middle portion of the chamber.

  Furthermore, the opening may be arranged in the inlet pipe.

  Furthermore, the openings can be arranged in the middle part of the chamber between the catalytic elements.

  Additionally, the venting port may be fluidly connected to a venting pipe fluidly connected downstream of the turbocharger.

  The smoke removal unit may have a plurality of openings, each opening having a valve fluidly connected to the conduit.

  Furthermore, all the conduits can fluidly connect these openings to the receiver.

  Furthermore, the smoke removal unit may have a plurality of receptacles, each receptacle being connected to one of the conduits.

  Also, the cross sectional conduit area may be less than 50%, preferably less than 30% of the cross sectional receiver area.

  Additionally, the conduit may have a conduit length greater than the diameter of the cross-sectional conduit area.

  Additionally, the conduit may have a conduit length that is 10% greater than the diameter of the cross-sectional conduit area, preferably 25% greater than the diameter of the cross-sectional conduit area, and more preferably 50% greater than the diameter of the cross-sectional conduit area.

  Furthermore, the chamber has a chamber volume and the receiver may have a receiver volume that is less than 20% of the chamber volume, preferably less than 10% of the chamber volume.

Also, sound insulation unit, a soot removal unit and / or NO _X reduction unit may be supposed to be at least partially surrounds.

  The smoke removal unit may have a valve control to control the opening of the valve.

Furthermore, the NO _x reduction unit may be located on the high pressure side of the turbocharger.

  Furthermore, the valve control unit may include a timer.

  Furthermore, the smoke removal unit may comprise a smoke sensor.

  The soot sensor may be a pressure sensor.

The combustion engine system according to the present invention may further comprise a second turbocharger arranged upstream of the NO _x reduction unit.

  Furthermore, the internal combustion engine of the combustion engine system may be a two-stroke or four-stroke internal combustion engine.

  The combustion engine system may further comprise an exhaust gas receiver.

  Furthermore, the combustion engine system may further comprise a scavenged gas receiver.

  Furthermore, the combustion engine system may further comprise a heat exchanger, such as, for example, a boiler.

  A non-return valve may be disposed in the vent pipe.

  Internal combustion engines can be operated with fuel having a sulfur content of at least 0.05%.

  The internal combustion engine may be a large two-stroke internal combustion engine.

  Additionally, the combustion engine system may comprise one or more catalytic reactor housings having a volume of at least 200 liters.

NO _X reduction unit may further comprise a reducing agent supply unit with a dosing unit for administering the amount of the reducing agent in the exhaust gas before entering or during entry into NO _X reduction unit.

Furthermore, NO _X reduction unit may further comprise a adapted control unit to reduce the amount of reducing agent supplied to the NO _X reduction unit.

  Additionally, the reducing agent may comprise ammonia.

The present invention also relates to a method for reducing soot in a chamber of a NO _x reduction unit in a combustion engine system according to the present invention. This method is
Opening a valve to allow some of the exhaust gas to escape into the conduit and into a receiver that generates sound waves that are further propagated into the chamber to loosen some of the soot in the chamber;
Closing the valve,
Ventilating the receptacle.

  The invention and its numerous advantages are explained in more detail below with reference to the attached schematic drawings. These figures show some non-limiting embodiments for the purpose of illustration.

It is a diagram of a combustion engine system having an NO _X reduction unit to the high-pressure side of the turbocharger. It is a diagram illustrating a NO _X reduction unit and soot removal unit. It is a perspective view of a smoke removal unit. FIG. 6 shows another NO _X reduction unit with two openings and another soot removal unit with two conduits connected to these openings. FIG. 7 shows another NO _x reduction unit with an opening upstream of the catalytic element and an opening downstream of the catalytic element. Each opening is connected to a smoke removal unit. It is a diagram of another combustion engine system having an NO _X reduction unit to the high-pressure side of the turbocharger.

  All the figures are very schematic and not necessarily to scale, showing only the parts that are necessary to clarify the invention, the other parts being omitted or only suggested .

FIG. 1 shows a combustion engine system 1 comprising an internal combustion engine 2 generating exhaust gas. The combustion engine system 1 includes a turbocharger 3 driven by the exhaust gas on the high pressure side of the turbocharger 3. The combustion engine system 1 further comprises an NO _x reduction unit 4 arranged upstream of the turbocharger, ie on the high pressure side of the turbocharger 3, this NO _x reduction unit from the internal combustion engine 2 by selective catalytic reduction (SCR) The engine is in fluid communication with the internal combustion engine 2 to purify the exhaust gases. NO _X reduction unit 4 includes a catalytic reactor housing 5 having a chamber 6, an inlet pipe 7, the outlet pipe 8, disposed in the chamber 6 of the catalytic reactor housing 5 between the inlet pipe 7 and outlet pipe 8 And one or more catalyst elements 9. Within NO _X reduction unit 4, soot is deposited on the catalyst elements 9 and on all surfaces of the inner catalytic reactor housing 5 during purification of exhaust gas. Thus, the combustion engine system 1 further comprises a smoke removal unit 10 for removing smoke at specific intervals. The soot removal unit 10 is fluidly connected to a valve 11 in the opening 12 of the catalytic reactor housing 5, the valve 11 being in a closed position where the opening 12 is closed and at least a portion of the exhaust gas in the catalytic reactor housing 5 Have an open position where they can escape into the soot removal unit 10.

As shown in FIG. 3, soot removal unit 10 comprises a receiver 14 having a cross-section receptacle area A _R and reservoir inlet 15 and vent port 16, the conduit 17 in fluid communication with reservoir inlet 15 to the valve 11 Further equipped. Conduit 17 initially transmits an acoustic wave into receiver 14 and thus moves the acoustic wave further into catalytic reactor housing 5 thereby moving catalytic reactor housing 5 and catalytic element 9. It has a cross-sectional conduit area A _C which is smaller than the cross-sectional receiver area A _{R in} order to loosen at least part of the upper soot. Exhaust gases escaping the soot removal unit 10 generates a standing wave, loosen soot therein the standing wave is moved in the NO _X reduction unit 4. When the valve 11 opens, the exhaust gas having a very high pressure escapes into the conduit 17 and also into the receptacle 14 having a substantially lower pressure, the cross-sectional conduit area A _C being greater than the cross-sectional receptacle area A _R Also by being small, sound waves are generated as well as Helmholtz resonators. This sound wave causes rapid transients in the local gas flow, leading to a rapid change in shear stress for the soot layer deposited on all the walls of the catalytic element 9, The smoke is loosened from the wall.

  The receiver has a vent port 16 as shown in FIG. 2 and the high pressure exhaust gas in the receiver 14 is released through the vent port 16 so that the pressure in the receiver 14 is reduced and the receiver 14 is ready to receive a new fraction of the exhaust gas when the valve 11 opens again. The pressure in the receiver 14 is released into the gas stream downstream of the turbocharger 3 via the vent pipe 18. An opening 12 is disposed in the chamber 6 upstream of the one or more catalytic elements 9 and when the valve 11 opens to generate an acoustic wave, a backflow simultaneously occurs in the catalytic reactor housing 5. This backflow further enhances soot removal.

  In FIG. 2, the opening 12 is located in the chamber 6 closer to the inlet pipe 7 than the middle portion 36 of the chamber 6. By locating the opening 12 closer to the inlet pipe 7 than the middle portion 36 of the chamber 6, or by having the opening 12 in the inlet pipe 7, a backflow is generated in the chamber 6 to loosen soot. In FIG. 4, the smoke removal unit 10 has a plurality of openings 12, each opening 12 having a valve 11 in fluid communication with a conduit 17, which is in fluid communication with a receptacle 14. The openings 12 are disposed in the middle portion 36 of the chamber 6 between the catalytic elements 9 to at least partially generate a backflow in the chamber 6 downstream of the openings 12 to loosen the soot. The smoke is also loosened by the sound waves generated in the smoke removal unit 10.

  In FIG. 5, the smoke removal unit 10 can have a plurality of receptacles 14, each receptacle 14 being connected to one of the conduits 17, one of the openings 12 being in the middle of the chamber 6 Located in the chamber 6 closer to the outlet pipe 8 than the portion 36, another opening 12 is located in the inlet pipe 7.

In FIG. 3, the cross-sectional conduit area A _C of the conduit 17 is less than 50%, preferably less than 30%, of the cross-sectional receiver area A _R. If the cross-sectional conduit area A _C of the conduit 17 is less than 50% of the cross-sectional receiver area A _R of the receiver 14, a larger sound wave is generated as compared to a smaller cross-sectional area difference. The chamber 6 has a chamber volume V _C , the receiver 14 has a receiver volume V _R , and the receiver volume V _R depends on the chamber volume V _C and how much during exhaust gas cleaning depending on whether the amount of soot is time deposit, less than 20% of the chamber volume V _C, preferably less than 10% of the chamber volume V _C. As shown, the conduit 17 has a conduit length L greater than the diameter of the cross-sectional conduit area A _C , and the conduit 17 is the “neck” of the soot removal unit 10 of the Helmholtz resonator design. Longer conduits / necks result in lower frequencies of sound waves generated when the valve 11 is opened. In one embodiment, the conduit 17 has a 10% greater conduit length L than the cross-sectional diameter of the conduit area A _C. In another embodiment, the conduit 17 has a conduit length L that is 25% greater than the diameter of the cross-sectional conduit area A _C , and in yet another embodiment the conduit 17 is greater than the diameter of the cross-sectional conduit area A _C 50% greater conduit length L. The sound waves generated by the high-pressure exhaust gas escaping into the soot removal unit 10 designed as a Helmholtz resonator result in a very loud sound, the frequency of this sound wave being determined by the cross-sectional conduit area A _C larger cross-section conduit area a _C results in a sound wave having a frequency higher than the result. The frequency is also determined by the chamber volume V _C , with larger chamber volumes V _C reducing the frequency.

High-pressure exhaust gas is generated by escaping to the soot removal unit 10 waves leads as a result a very loud sound, thus combustion engine system 1, soot removal unit shown in FIG. 4 10 and / or NO _X reduction A sound insulation unit 19 is provided which at least partially encloses the unit 4.

In FIG. 6, the smoke removal unit 10 may have a valve control 37 for controlling the opening of the valve 11. The valve control unit 37 may include a timer (not shown) for operating the valve 11 at predetermined time intervals. The smoke removal unit 10 may have a smoke sensor 38 for making measurements when smoke is deposited in the catalytic reactor housing 5. Soot sensor 38 is a acoustic sensor for may be a pressure sensor, or to further measure the thickness of the soot layer in the catalytic reactor housing 5 for measuring the back pressure in the NO _X reduction unit 4 May be Therefore, the smoke sensor 38 may be in communication with the valve control unit 37. The combustion engine system 1 further includes a second turbocharger 21 disposed upstream of the NO _x reduction unit 4 and upstream of the other turbochargers 3. NO _X reduction unit 4, between the between the turbocharger, thus fluidly connected in a high pressure side of the second turbocharger 21.

  The internal combustion engine 2 of the combustion engine system 1 may be a two-stroke or four-stroke internal combustion engine 2. As shown in FIG. 1, the combustion engine system 1 may further comprise an exhaust gas receiver 31, a scavenging gas receiver 32, and a heat exchanger (not shown) such as, for example, a boiler. The turbocharger 3 includes a turbine 33 driven by the exhaust gas, and the turbine 33 drives a compressor 34.

  In FIG. 5, the smoke removal unit 10 has two receptacles 14, one receptacle 14 being fluidly connected to the opening 12 in the inlet pipe 7 via a conduit 17 and the other receptacle 14 being It is in fluid communication with the bottom of the catalytic reactor housing 5 closer to the outlet pipe 8 than the catalytic element 9. A check valve 35 is disposed in the vent pipe 18 to allow the exhaust gas to flow away from the receiver 14 while preventing the exhaust gas from flowing back again.

  The internal combustion engine 2 may be a large two-stroke internal combustion engine and is operated with fuel having a sulfur content of at least 0.05%. The catalytic reactor housing 5 has a volume of at least 200 liters. The two-stroke internal combustion engine 2 may be a compression ignition cross-head internal combustion engine 2 with a large two-stroke uniflow turbocharger, used as a propulsion system for large vessels or as a stationary engine of a power plant. Due to the large height, width, weight, and power, this large two-stroke uniflow turbocharged compression ignition cross-head internal combustion engine 2 differs significantly from a typical combustion engine and is far superior to others There is. The total output of a single engine 2 may exceed 100.000 BHP.

NO _X reduction unit 4, the reducing agent supply unit (shown with a dosing unit for administering the amount of the reducing agent in front entrance during or entry into NO _X reduction unit 4 into the exhaust gas (not shown) And the reductant comprises ammonia.

The present invention allows opening of the valve 11 to allow a portion of the exhaust gas to escape into the conduit 17 and further into the receiver 14, thereby generating an acoustic wave, which propagates into the chamber 6. Thus, by loosening a portion of the soot in the chamber 6, the smoke reduction method for reducing the soot in the chamber 6 of the NO _x reduction unit 4 in the combustion engine system 1 is provided. The valve 11 is then closed. The receptacle 14 is simultaneously vented.

  While the invention has been described above in connection with the preferred embodiments of the invention, it will be appreciated by those skilled in the art that a plurality of modifications can be considered without departing from the invention as defined by the following claims. It will be clear.

Reference Signs List 1 combustion engine system 2 internal combustion engine 3 turbocharger 4 NO _X reduction unit 5 catalyst reactor housing 6 chamber 7 inlet pipe 8 outlet pipe 9 catalyst element 10 smoke removal unit 11 valve 12 opening 14 receiver 15 receiver inlet 16 vent port 17 Conduit 18 Vent pipe 19 Sound insulation unit 21 Second turbocharger 31 Exhaust gas receiver 32 Scavenged gas receiver 33 Turbine 34 Compressor 35 Check valve 36 Middle part 37 Valve control part 38 Smoke sensor

Claims (10)

A combustion engine system (1),
An internal combustion engine (2) that generates an exhaust gas including soot and smoke;
A turbocharger (3) driven by the exhaust gas;
Wherein disposed upstream of the turbocharger, the An internal combustion engine fluid concatenated NO _X reduction unit to the internal combustion engine (2) for purifying the exhaust gas from (2) (4), the soot the NO _X reduction unit to deposit inside (4),
Catalyst reactor housing (5) with chamber (6), inlet pipe (7) and outlet pipe (8), and said catalytic reactor housing between the inlet pipe (7) and the outlet pipe (8) One or more catalytic elements (9) arranged in the chamber (6) of (5)
Comprises an NO _X reduction unit (4),
A combustion engine system (1) comprising
The combustion engine system (1)
A smoke removal unit (10),
A receiver (14) having a cross-sectional receiver area (A _R ) and a receiver inlet (15) and a vent port (16);
A flue removal unit fluidly connecting the receiver inlet (15) to a valve (11), and a conduit (17) having a cross-sectional conduit area (A _c ) smaller than the cross-sectional receiver area (A _R ) (10)
In the combustion engine system (1) further comprising
The soot removal unit further comprises the valve (11) in fluid communication with the opening (12) of the catalytic reactor housing (5), the valve (11) being within the catalytic reactor housing (5) A combustion engine system (1), characterized in that it has an open position allowing at least a part of the exhaust gases of to escape into the soot removal unit (10).   The combustion engine system (1) according to claim 1, wherein the opening (12) is arranged in the chamber (6) upstream of the one or more catalytic elements (9).   The combustion engine system (1) according to claim 1 or 2, wherein the ventilation port (16) is fluidly connected to a ventilation pipe (18) fluidly connected downstream of the turbocharger (3). A combustion engine system (1) according to any one of the preceding claims, wherein said cross-sectional conduit area (A _C ) is less than 50%, preferably less than 30%, of said cross-sectional receiver area (A _R ) ). It said conduit (17), the cross-sectional conduit area (A _C) diameter larger conduit length than in having (L), according to claim 4 the combustion engine system (1). Said conduit (17), the 10% larger than the diameter of the cross-section conduit area _{(A C),} preferably 25% greater than the diameter of the cross-sectional conduit area _{(A C),} more preferably the cross-sectional conduit area (A A combustion engine system (1) according to claim 4, having a conduit length (L) 50% greater than the diameter of _C ). Said chamber (6) has a chamber volume _{(V C),} the receiver (14) is less than 20% of the chamber volume _{(V C),} 10 preferably of the chamber volume _{(V C)} A combustion engine system (1) according to any one of the preceding claims, having a receiver volume (V _R ) that is less than%. Sound insulation unit (19) comprises at least partially surrounds the soot removal unit (10) and / or NO _X reduction unit (4), a combustion engine system according to any one of claims 1 7 (1 ). Further comprising a combustion engine system according to any one of claims 1 to 8 the second turbocharger arranged upstream (21) of the NO _X reduction unit (4) (1). A method for reducing smoke in a combustion engine system (1) according to any one of claims 1 to 9, for reducing smoke in a chamber (6) of the NO _x reduction unit (4),
The step of opening the valve (11) to allow a portion of the exhaust gas to escape into the conduit (17) and further into the receptacle (14) and propagate into the chamber (6) Generating a sound wave to loosen part of the soot in the chamber (6),
Closing the valve (11);
Venting the receptacle (14);
Method, including.

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