Dosing Components for SCR-Systems - Hilite Components for SCR-Systems ... bal climate change. ......

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Dosing Componentsfor SCR-Systems

Series development and manufacturing of Innovative Systems and Components for the Automotive Industry

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The innovative, global development partner and series supplier for the Automotive IndustryThe innovative, global development partner and series supplier for the Automotive Industry

The future stringent emission require-ments for heavy duty diesel trucks in the USA, Europe and Japan will make it ne-cessary to use an emission control sys-tem to reduce fuel consumption, NOx, CO and particulate matter.

For many years Hydraulik-Ring develops dosing systems and components for ex-haust aftertreatment systems functioning according to the SCR-principle.

The components made by Hydraulik-Ring have been used successfully in se-ries production for many years.The requirements dosing systems must meet as to installation size, precise do-sing and cost are constantly increasing.

With Hilite / Hydraulik-Ring you have a partner who offers optimal solutions for your application requirements.

Hilite-SCR-SystemInhalt

Hilite-SCR-System 2

Emission standards 3

Trade-off 4

Chemical Processes in the SCR-System 4

SCR-Components Gen1- Air-Assisted 5

SCR-Components Gen 2 - Liquid Only 6

Spray of the Dosing System Gen 2 6

Simulation 7

Test Potentials 7

Features SCR-System 7

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Abbrevitations in this brochure:

SCR = Selective catalytic reduction

g/bhp-hr = Grams per brake horsepower-hour

g/kWh = Grams per kilowatt hour

HC = HydrocarbonNOx = Oxides of nitrogenPM = Particulate matterAdBlue® = 32,5% aqueous urea

water solutionEGR = Exhaust gas

recirculationDPF =Dieselparticulatefilter

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Emission standards

Roadtraffichasasubstantialpartinglo-bal climate change. Especially heavy duty vehicles cause over 50% of the particu-late and NOx emission.Particularly Diesel engines emit eight to ten times more NOx than gasoline engi-

In past years legislation has reacted with increasingly stricter emission standards especially for diesel powered vehicles.

nes although in the average they are 10-25% less thursty and thus emit less CO2 (-11%). This positive effect is anulled by the emission of particulate matter (soot) and NOx.

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Trade-off

Measures which can be taken within the engine had to reduce fuel consumption and particulate matter, but at the same time the amount of NOx increases. Star-ting with Euro 5 we can only get Diesel engines clean by exhaust aftertreatment.During the aftertreatment particulate mat-ter and NOx are reduced. If in the opposite case NOx emission is reduced by measures inside the engi-ne, e.g. EGR (exhaust gas recirculation) which lowers the combustion tempara-ture the amount of particulate matter and fuel consumption increase.

The SCR-system solves this trade-off by reducing fuel consumption inspite of re-duction of PM and NOx.

Wege um die entsprechenden Emissionsgrenzwerte zu erreichen

Chemical Processes in the SCR-System

In the SCR-process (Selective catalytic reduction) ammonia reacts, in a special catalyst at a certain temperature with the NOx in the exhaust fumes. Since pure ammonia is a dangerous substance, we inject in the SCR-pro-cess a 32.5 % aqueous solution (Ad-Blue®) into the exhaust tract before it enters the SCR-catalyst. Ammonia is released by means of a hydrolytic reaction and can react with the NOx in the SCR-catalyst. Hydrolysis is the split-ting of a chemical compound by reac-tion with water. In this split one hydrogen atom goes to one “split-off piece“ andthe remaining hydroxyl group goes to the other piece.

The quantity of the injected urea depends on the NOx emission of the engine and thus on the current engine speed and tor-que. Therefor it is indispensable to control the injection process exactly.

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SCR-Components Gen1- Air-Assisted

Schematic diagram SCR-system gen1 air-assisted

Application of the components Supply unit Dosing unit

In the dosing system of the first gene-ration a pump transfers AdBlue® to the dosing unit. There depending of tempe-rature and pressure the AdBlue® is do-sed by an injection valve into a tube in which it is transported by an accelerated air stream as an aerosol to the injection nozzle in the exhaust gas.

The system is abt for contolled concepts, above all for vehicles with compressed air equipment.

Since 2005 more than 1000 times produced in series

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SCR-Components Gen 2 - Liquid Only

Spray of the Dosing System Gen 2

Dosing systems of the second generation work without compressed air. Their spe-cial feature is the exact dosing into the exhauststreambymeansofapredefinedspray behaviour. This allows the system to work still more precisely in closed loop systems.

Leagal requirements increase, package sizes cannot grow any bigger (Tank, Ad-Blue® tank, aggregates, catalysts, particle filtersetc.).Thismeans,thatconstructionspace is getting smaller, the distance for the hydrolytic process is getting shorter and its form is changing etc. Hilite is in the position to consider all these factors and to adopt the system to individual conditions and requirements.

Spray process initial phase

Supply unit Dosing unit

Spraying phase Spray process final phase

Exact spray (Drop sizes < 27 µm) is deci-sive for the hydrolysis (further evaporation and splitting into ammonia and CO2), so that the ammonia can react in the cata-lyst.

Finest spray allows excellent conversion rates (amount of the NOx reduction), but also the exact quantity is important since otherwise the conversion rates deteriorate and the ammonia slip becomes too big.

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Simulation

Stream behaviour Drop behaviour during hydrolysis

Test Potentials

Very small drop size

Ideally adapted distribution

Most precise dosing quantity

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Simulation tools help to optimize systems and to apply them virtually. Thus we can e.g. determine both the optimal point of injection and the optimal injection angle.

Spray distrinution

Highly dynamic adaption to engine operating condition

Robust system

Series experience due to 1000 times series application day in day out.

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Features SCR-System

Hydraulik-Ring equipped with state of the art test equipment:

Climatic chambers for any heat and frost tests Test stands for endurance testing of pumps, valves and actuators Shaking test stands which allow to expose the test specimen to maxi-mum g-powers in all directions

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Hot gas test stand to measure the exact behaviour of the components at the exhaust pipeComponent test stands Malvern Spray Analyzer for measu-ring the exact drop size.

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Climatic chamber Component test stands Test stand for measuring drop size

Ratio: drop size / hair

www.hilite.com - [email protected]

Engine Applications Transmission Applications

Components for Emission Systems

Valves

Sales Office in USA:2701 Cambridge CourtSuite 218Auburn Hills, Mi. 48326Tel.: 248.475 - 4580Fax: 248.475 - 4581

Sales Office in Europe:

Am Schlossfeld 597828 MarktheidenfeldTel.: +49 (0) 9391 911- 01Fax: +49 (0) 9391 911- 121

Dosing Components for SCR-Systems - Hilite Components for SCR-Systems ... bal climate change. ......

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