DE102009017936A1 - Air supply device for supercharged internal combustion engine, particularly for marine diesel engine, has exhaust turbocharger with compressor for compressing air for internal combustion engine - Google Patents

Abstract

The air supply device has an exhaust turbocharger with a compressor for compressing air for the internal combustion engine, and a turbine driven by exhaust gas of the internal combustion engine. A charged humidifier is provided for cooling of charged air from the compressor by sea water. An exhaust gas scrubber (4) is provided for cleaning, particularly for flue gas desulfurization of the exhaust gas of the internal combustion engine. A unit is provided for supplying waste water form charged humidifier into the exhaust gas scrubber. An independent claim is also included for a method for reducing contaminants, particularly sulfur oxide and nitrogen oxide in exhaust gas of a supercharged internal combustion engine.

Description

The The invention relates to an air-guiding device for a supercharged internal combustion engine, in particular for a Diesel engine, with an exhaust gas turbocharger, which is a compressor for Compressing air for the internal combustion engine and a exhaust gas of the internal combustion engine drivable turbine comprises, a Charge air humidifier for cooling charge air from the compressor using seawater and an exhaust scrubber for cleaning, in particular for flue gas desulphurisation, of exhaust gas from the internal combustion engine, an internal combustion engine, in particular a marine diesel, with a Such air guide device and a method for Reduction of pollutants in the exhaust gas of such an internal combustion engine.

From the EP 0 701 656 B1 is a implemented under the name "Humid Air Motor" (HAM) in practice air ducting device according to the preamble of claim 1 for reducing pollutants, especially sulfur (SO _x ) and nitrogen oxides (NO _x ) in the exhaust of large supercharged diesel engine such as one Main engine of a ship known: the emergence of NO _x depends essentially on temperature peaks during combustion in the cylinders. These can be reduced by the fact that charge air from the compressor of the exhaust gas turbocharger is moistened and cooled by sea or sea water before entering the combustion chambers. In this way, local combustion temperature peaks and thus the proportion of thermally formed nitrogen oxide can be lowered.

Returned exhaust gas is in the from the EP 0 701 656 B1 known air ducting device humidified and cleaned by an exhaust scrubber, which can also be operated with seawater.

Object of the present invention is that of the EP 0 701 656 B1 to improve known air guide device.

Of the The core of the present invention lies in the use of the enriched Waste water from the charge air humidification for waste gas scrubbing. Its alkalinity increases efficiency the exhaust scrubbing, whereby the reducing agent use advantageously can be reduced. This can lead to a reduction in size and thus plant weight and / or to a reduced use of chemicals not just the investment and operating costs but can also protect the environment.

A Air guiding device according to the present invention serves for the supply of combustion air and the removal of exhaust gases charged internal combustion engine such as a large Diesel engine, in particular a marine diesel. It includes one Exhaust gas turbocharger with a compressor for compressing air, in particular sucked Fresh air, to charge air for the internal combustion engine and a turbine exhaust driven by the internal combustion engine, the in turn, preferably directly, drives the compressor and so on Increased efficiency of the internal combustion engine.

In a charge air humidifier between the compressor and the combustion chambers the internal combustion engine can be arranged, is liquid and / or evaporated sea or sea water supplied, for example Injected or injected to the charge air from the compressor to cool and partially clean.

In a water separator is at least a part of the supplied Seawater discharged as wastewater again, with the charge air a portion of the seawater as at least partially saturated or supersaturated Add air into the combustion chambers of the internal combustion engine can there to local combustion temperature peaks and thus the Lower the proportion of thermally formed nitrogen oxides.

This Wastewater, which by contact with the hot charge air partially distilled and enriched, is in one preferred embodiment in a heat exchanger for heating, evaporating and / or overheating used fresh seawater, which then the charge air humidifier is supplied.

By a suitable device, the one or more lines, corresponding Have control valves and / or one or more pumps can, this enriched, alkaline wastewater from the charge air humid ter fed into an exhaust gas scrubber used for cleaning, in particular for wet flue gas desulfurization of exhaust gas from the internal combustion engine serves.

On This way, wastewater from the charge air humidifier in the scrubber used again, thus increasing its efficiency. advantageously, so can also have a separate intake of seawater for the scrubber or a separate derivation for Wastewater from the charge air humidifier omitted, so that beneficial less valves, pumps, filters and the like needed become.

In a preferred embodiment, one or more collectors are provided for seawater, which can be conveyed by at least a first pump in a collector. At least one second pump can feed seawater from a collector into the charge air humidifier. At least one third pump may be used to deliver from be provided from a collector in the scrubber water. As a result, the quantities of seawater in the collector, charge air humidifier and exhaust gas scrubber can be suitably regulated, if appropriate also independently of one another.

Prefers The collector (s) comprise the one explained above Heat exchangers to get fresh seawater through from the sewage discharged from the compressed and thus heated charge air Preheat heat or vaporize or overheat. This heat exchanger may preferably be in the same, opposite or cross-flow can be operated.

In A preferred embodiment is a bypass or passage from a first pump to the exhaust scrubber for bypassing provided the charge air humidifier to optionally seawater, at least proportionately, even without passing through the charge air humidification, in particular, bypassing a heat exchange, as washing water to be able to lead the exhaust scrubber. Preferably is such a bypass by one or more control valves shut off.

additionally or alternatively, a supply means for supplying additional Washing water, especially fresh water, to the scrubber be provided. Such a supply device preferably has at least a pump for conveying the washing water and / or a or several control or Regelven tile to shut off the supply and is preferably downstream of the charge air humidifier, in particular downstream of a collector and / or heat exchanger arranged to be independent of the charge air humidification Washing water supply or admixture to wastewater from the charge air humidification display.

Especially, if a bypass and / or a supply device for the supply of additional washing water is provided, one or more control valves between the charge air humidifier and the scrubber, in particular downstream to a collector and / or heat exchanger be arranged to optionally also a waste gas without Use or mixed with waste water from the charge air to enable.

Prefers is a discharge device for the discharge of waste water from the scrubber associated with a discharge of wastewater from the charge air humidifier, so as to further reduce the expenditure on equipment.

One Waste gas from the charge air humidification can be fed to waste gas scrubbers can be used for cleaning exhaust gas emitted into the environment and / or for Purification of exhaust gas serve, which is the combustion air before or supplied after the compression in the compressor of the exhaust gas turbocharger becomes.

Further Advantages and features emerge from the subclaims and the embodiments. This shows, partially schematically:

1 : A supercharged internal combustion engine with an air guide device according to a first embodiment of the present invention;

2 : A supercharged internal combustion engine with an air guide device according to a second embodiment of the present invention; and

3 : A supercharged internal combustion engine with an air guide device according to a third embodiment of the present invention.

1 shows a charged marine diesel 1 with an air guiding device according to a first embodiment of the present invention. A compressor 2.1 an exhaust gas turbocharger sucks in fresh air FL and compresses it. This charge air is in a charge air humidifier 3 moistened with seawater and thereby cleaned and cooled.

For this purpose, a first pump P1 promotes sea or seawater SW in a collector 5 in which it is replaced by heat exchange with waste water from the charge air humidifier 3 is preheated.

A second pump P2 delivers seawater from the collector 5 in the charge air humidifier 3 into which it is injected and, with evaporation, cools the compressed charge air. The charge air carries a portion of the resulting water vapor into the combustion chambers of the ship's diesel 1 while the remaining enriched warm wastewater is returned to the collector where it is used to preheat fresh seawater. Alternatively, fresh seawater can also at least partially already in the collector 5 evaporated or even overheated and as a water-steam mixture or steam the charge air humidifier 3 are fed, wherein in the evaporation accumulating concentrated residual water in the collector 5 remains and can be mixed with wastewater from the charge air humidifier.

A turbine 2.2 the exhaust gas turbocharger is exhaust gas of the ship's diesel 1 driven, then an exhaust scrubber 4 is supplied. In these, sewage is removed from the collector 5 injected. For this purpose, a third pump P3 sucks enriched alkaline wastewater from the charge air humidifier when the control valve V2 is open and the control valve V1 is closed 3 from the collector 5 and feeds it via a supply line d into the scrubber 4 one. The wastewater cleans and cools the exhaust AG from the Marine diesel, which can then be cleaned to the environment. The wastewater collected from the scrubber in a lower mist eliminator 4 is derived via a three-way valve V3 into the sea. In particular, sulfur dioxide SO ₂ and sulfur trioxide SO _{3 are} reacted with the wash water in sulfur scrubber or sulfuric acid H ₂ SO ₃ or H ₂ SO ₄ in the scrubber scrubber, which is converted into harmless sulfite SO ₃ ^2- or sulfate by the alkaline enriched waste water from the charge air humidifier SO ₄ ^{2- is} neutralized, which is already contained in the seawater as a natural component and therefore this can be fed easily.

In an alternative operating mode, by appropriate control of the control valves V1, V2 and fresh seawater SW with the wastewater from the collector 5 mixed (valves V1, V2 each fully or partially open) or alone (V1 open, V2 closed) as washing water for the scrubber 4 be used.

In this case, the three-way valve V3 is a discharge of waste water from the collector 5 and / or the scrubber 4 allow, while advantageously, a backflow of waste water from the scrubber 4 to the collector 5 is prevented.

2 shows a charged marine diesel 1 with an air guiding device according to a second embodiment of the present invention. Features which correspond to the first embodiment are designated by identical reference symbols, so that only the differences from the first embodiment are discussed below.

• – nur mit Abwasser vom Ladeluftbefeuchter 3 bzw. aus dem Sammelbehälter 5 (Ventil 1 geschlossen, Ventil V2 offen, Pumpe P4 aus),
• – nur mit frischem Seewasser SW (Ventil 1 offen, Ventil V2 geschlossen, Pumpe P4 aus),
• – nur mit Waschwasser WW, beispielsweise Frischwasser (Ventil 1, 2 geschlossen, Pumpe P4 an), oder
• – mit einer gewünschten Mischung (Ventil 1 teilweise geschlossen und/oder Ventil V2 teilweise geschlossen und/oder Pumpe P4 an)

versorgt werden kann.In this embodiment, an additional supply of washing water WW is provided as an alternative to the bypass b of the first embodiment, which can be supplied via a fourth pump P4. By appropriate control of the control valve V2 so fresh seawater or fresh water the wastewater from the collector 5 mixed (valve V2 at least partially open) or the scrubber 4 only be charged with this washing water WW (V2 closed). In a further development, not shown, the first and second embodiments may also be combined, so that by appropriate control of the control valve V1 and V2 and the pump P4 of the scrubber 4 optional

• - only with waste water from the charge air humidifier 3 or from the collection container 5 (Valve 1 closed, valve V2 open, pump P4 off),
• - only with fresh seawater SW (valve 1 open, valve V2 closed, pump P4 off),
• - Only with washing water WW, for example, fresh water (valve 1, 2 closed, pump P4 on), or
• With a desired mixture (valve 1 partially closed and / or valve V2 partially closed and / or pump P4 on)

can be supplied.

3 shows a charged marine diesel 1 with an air guiding device according to a third embodiment of the present invention. Features consistent with the first and second embodiments are designated by identical reference numerals so that only the differences from the first embodiment will be discussed below.

In the third embodiment, an exhaust gas recirculation is provided, in which an exhaust pipe from the marine diesel 1 in one the turbine 2.2 charging line i1 and a line i2 branches, in which a part of the exhaust gas through an exhaust gas scrubber 4 , as explained above, cleaned, cooled and moistened and then ( 3 ) or previously compressed by a compressor K to the pressure of the charge air, before it is the charge air from the compressor 2.1 the exhaust gas turbocharger is supplied. Although not shown, as in the first and / or second embodiment, a bypass b, a supply means P4 for supplying additional washing water WW and / or a (further) exhaust gas scrubber for purifying exhaust gas from the turbine 2.2 be provided of the exhaust gas turbocharger.

1

marine diesel (Internal combustion engine)

2.1

compressor the exhaust gas turbocharger

2.2

turbine the exhaust gas turbocharger

3

charging humidifier

4

exhaust gas scrubber

5

collector (with heat exchanger)

pi

ite pump

V1, ... V3

Valve

SW

seawater

WW

wash water

a, ... i1, i2

management

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• EP 0701656 B1 [0002, 0003, 0004]

Claims (9)

Air guiding device for a supercharged internal combustion engine, in particular for a diesel engine ( 1 ), with an exhaust gas turbocharger with a compressor ( 2.1 ) for compressing air (FL) for the internal combustion engine and an exhaust gas (AG) of the internal combustion engine driven turbine ( 2.2 ); a charge air humidifier ( 3 ) for cooling charge air from the compressor by means of seawater (SW); and an exhaust scrubber ( 4 ) for cleaning, in particular for flue gas desulfurization, of exhaust gas from the internal combustion engine; characterized by means (d, P3) for feeding waste water from the charge air humidifier ( 3 ) in the scrubber ( 4 ). Air guiding device according to claim 1, characterized by a first pump (P1) for conveying seawater (SW) into a collector ( 5 ); a second pump (P2) for pumping seawater from a collector ( 5 ) into the charge air humidifier ( 3 ); and / or a third pump (P3) for pumping waste water from a collector ( 5 ) in the scrubber ( 4 ). Air guiding device according to claim 2, characterized by a bypass (b) from the first pump (P1) to the exhaust gas scrubber ( 4 ) bypassing the charge air humidifier ( 3 ). Air guiding device according to one of the preceding claims, characterized by a supply device (P4) for supplying additional washing water (WW) to the exhaust gas scrubber ( 4 ). Air guiding device according to one of the preceding claims, characterized by a discharge device (e) for discharging waste water from the exhaust gas scrubber ( 4 ) with a discharge (f) of waste water from the charge air humidifier ( 3 ) connected is. Air guiding device according to one of the preceding claims, characterized by an exhaust gas recirculation (i2), in which an exhaust gas scrubber ( 4 ) with a device (d, P3) for feeding wastewater from the charge air humidifier ( 3 ) is arranged. Use of waste water from the charge air humidifier ( 3 ) an air guiding device according to one of the preceding claims for cleaning, in particular for flue gas desulfurization, of exhaust gas from an internal combustion engine. Charged internal combustion engine, in particular marine diesel, with an air guiding device according to one of the preceding Claims 1 to 6. Process for reducing pollutants, in particular sulfur oxides (SO _x ) and nitrogen oxides (NO _x ), in the exhaust gas of a supercharged internal combustion engine comprising the steps of: humidifying charge air supplied by the internal combustion engine by means of seawater; and purifying exhaust gas of the internal combustion engine by means of washing water; characterized in that waste water of the charge air humidification is used as wash water for purifying exhaust gas.