Technical information. VCM Valve Control Management The heart rate reactor

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1 Technical information VCM Valve Control Management The heart rate reactor

2 VCM Valve Control Management VCM module in position above the normal engine valves. The ability to control valve timing and valve lift on combustion engines brings a range of benefits in terms of engine operating performance, emissions and fuel consumption. Following widespread use in the automotive sector, the technology is now arousing interest in the large engine sector served by ABB Turbocharging. It is seen as an enabling technology for a number of measures on 4-stroke diesel and gas engines which target lower emissions, reduced fuel consumption, increased power density and enhanced transient behavior. Proven technology Anticipating this demand, in 2009 ABB Turbocharging agreed a collaboration with one of the leading exponents of variable valve timing in the automotive sector, German engine component specialist Schaeffler Technologies GmbH & Co. KG. The agreement centers on the development of the UniAir variable valve train system for automotive engines to suit applications on large 4-stroke diesel and gas engines with power outputs above 400 kw. VCM The result of the cooperation is VCM V = Valve C = Control of timing and/or lift M = Management in steady or transient mode Like UniAir, it uses electro-hydraulic technology to achieve progressive variation of timing/lift of the inlet or exhaust valve. VCM offers the following features: Stepless: Unlike purely mechanical systems, e.g. those which vary the positions of the fulcrums of cam followers to change the timing of valve actuation and valve stroke, VCM offers a wider range of fully proportional control of valve timing/lift. Compact and add-on: The VCM system combines all elements in a single module which can be readily installed on 4-stroke engines. The majority of VCM equipment is located under the valve cover, and by using the engine lube oil as its hydraulic fluid and a simple solenoid valve as its control organ, only two control/supply connections are required.the system also requires no major changes to engine architecture and the modules are readily fitted during the assembly process at the engine builder s works. 2

3 VCM applications V for Versatile The stepless variation in valve timing and lift achievable with VCM represents a versatile tool for: Varying Miller Cycles on coming generations of low emissions diesel and gas engines Closely adapting engine performance to the operating profile of a given engine application, e.g. switching from emissions to fuel optimized modes Potential for realizing internal exhaust gas recirculation on 4-stroke engines Enabling Miller Indeed, ABB Turbocharging sees VCM s foremost application as one of the major enabling technologies for engine builders seeking to exploit strong Miller Cycles as a route to far lower emissions of NO x. The Miller Cycle is an ingenious way of cooling the cylinder charge of diesel engines to eliminate the combustion chamber temperature peaks responsible for over 90 % of NO x formation. On gas engines, the technique can be used to substantially increase power density. Miller Cycle principle On 4-stroke engines, substantial cooling of the engine intake air is achieved by shortening the opening period of the inlet valve and so reducing the time during which the cylinder charge can enter the cylinder on the induction stroke. The earlier end of induction promotes expansion, and hence cooling in the cylinder charge. However, the short valve timings of the strong Miller Cycles needed to achieve the kinds of NO x reductions prescribed in planned emissions legislation are matched to a diesel or gas engine operating at its Maximum Continuous Rating, or MCR. At lower loads, longer valve opening periods are needed to avoid emissions of smoke and particulate matter and poor engine response to load changes due to intake air deficiency. VCM solution With its capability to vary valve timing, VCM provides engine builders with a powerful tool for adapting the strength of Miller Cycles across the complete operating load and speed ranges of 4-stroke diesel and gas engines. inlet exhaust inlet exhaust [%] Single stage turbocharging Power2 two stage turbocharging Standard inlet valve closure near BDC TDC Induction stroke BDC Miller inlet valve closure before BDC Specific fuel consumption Strong Miller NO x [%] Emissions Early Miller Cycle and standard induction at the moment of inlet valve closure. Shifting the curve fuel consumption and NO x reduction potential using two stage turbocharging to achieve strong Miller Cycles on further developed diesel engines. 3

4 How VCM works VCM achieves stepless variation in valve timing by interposing a high pressure oil chamber in the engine valve train between the valve and its mechanical actuation system. A solenoid valve varies the filling of the chamber with engine lube oil pressurized by a camshaft-actuated pump. This enables both the timing of the opening and closing of the valve to be varied as well as the distance the valve opens (valve lift). The pump also feeds a brake unit to limit forces when the valve contacts its seat. Pressure accumulator Intermediate pressure chamber Oil supply Engine valves Pump unit High pressure chamber Solenoid valve Actuator/brake Camshaft The VCM system varies valve timing and lift by introducing a high pressure oil chamber into the engine valve train. Full lift Early closure Valve lift Camshaft angle Camshaft angle Valve lift Valve lift Late opening/early closure, limited lift Double opening Valve lift Camshaft angle Camshaft angle 4

5 ABB Turbocharging A unique partner for advanced engine components. VCM Valve Control Management is a major element in ABB Turbocharging s growing portfolio of products and services for engine builders and engine end users. Their common aim is to optimize the performance, economy, reliability, availability, life cycle costs and not least the exhaust emissions of diesel and gas engines. Proactive solutions For ABB Turbocharging this means proactively addressing the needs and concerns of both engine builders and engine end users to devise solutions which are both effective and economic. Complementary VCM is one of two complementary building blocks ABB Turbocharging is offering to address the current major concerns of engine builders: Compliance with the strict limitations on emissions of oxides of nitrogen (NO x ) from engines on land and at sea due to be implemented in the middle of the present decade Increasing fuel efficiency in the face of the steady rise in the price of fossil fuels and international agreements governing emissions of the greenhouse gas carbon dioxide (CO 2 ) VCM and Power2 interaction Meshing perfectly with VCM is ABB Turbocharging s Power2 two stage turbocharging system. These complementary technologies represent essential enablers of variable Miller Cycles on large 4-stroke engines. On the one hand, Power2 provides the high turbocharging pressure ratios needed for the very strong Miller Cycles required to realize high NO x reduction percentages. On the other hand, VCM allows engine gas exchange to be optimized over a full range of engine operating conditions, hence allowing the effect of the Miller Cycle to be varied. Via its effect on engine gas exchange, VCM is also an effective method of varying the output of the two turbochargers in the Power2 system. Unique development partner With these technologies, ABB Turbocharging is a unique partner for two of the major on-engine systems required by diesel and gas engine builders to prepare their products for the new era of strict global emissions limitations. 5

6 Emissions compliance IMO Tier III and EPA Tier 4 are typical of the emissions legislation to be enacted in the middle of the present decade, affecting engines with outputs over 500 kw. IMO Tier III The third stage of marine engine emissions legislation issued by the International Maritime Organisation and due in 2016 builds on IMO Tier II. In 2016 the generally applicable 20 % reduction in NO x emissions vis-à-vis IMO Tier I (introduced 2000) continues to govern NO x emissions on the high seas. However, IMO Tier III demands an 80 % reduction in NO x emissions from vessels operating in Emissions Control Areas, or ECAs. EPA Tier 4 standards Emissions standards issued by the USA s Environmental Protection Agency cover NO x emissions from water borne, mobile and stationary engines of all sizes used in a wide range of applications. Up to 2015, the EPA Tier 4 standard requires NO x emissions to be reduced by around 90 % compared to the 2008 Tier 1 baseline. IMO NO x curves ECAs are, broadly, coastal waters close to areas of population or environmentally sensitive locations. ECAs already designated are the complete East and West Coasts of the USA and Canada, straits like the English Channel, landlocked seas like the Baltic and numerous port approaches. 6 [g/kwh] NO x Tier I Tier II Tier III, from 1 January [1/min] Speed

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8 ABB Turbocharging Service network CHTUS EN 2012 ABB Turbo Systems Ltd, Baden/Switzerland Aalborg Aberdeen Adana Algeciras Antwerp Baden Bangkok Barcelona Bergen Bremerhaven Brisbane Buenos Aires Busan Cape Town Casablanca Cebu Chennai Chicago Chittagong Chongqing Colombo Copenhagen Dakar Dalian Dar es Salaam Davao Delhi Dortmund Douala Dubai Durban Fort de France Freeport Fukuoka Gdansk Genova Gothenburg Guangzhou Guatemala City Hakodate Hamburg Helsinki Hong Kong Houston Incheon Istanbul Izmir Jakarta Jeddah Kaohsiung Karachi Kobe Lahore Las Palmas Le Havre Lima Limassol Los Angeles Lunenburg Madrid Malta Manaus Manila Mannheim Marseille Melbourne Miami Montreal Mumbai Naples New Orleans New York Onomichi Oporto Oslo Panama Perth Piraeus Qingdao Quito Rijeka Rio de Janeiro Rotterdam Saint Nazaire Santo Domingo Santos Seattle Shanghai Singapore Southampton St. Petersburg Suez Sunderland Surabaya Sydney Talcahuano Tallinn Telford Tianjin Tokyo Vadodara Vancouver Varna Venice Vizag Vung Tau (Status: July 2012) ABB Turbo Systems Ltd Bruggerstrasse 71 a CH-5401 Baden/Switzerland Phone: Fax: turbocharging@ch.abb.com