The Large Engine Research Facility at PSI 1* 1 K. Hoyer , P. Dietrich 2 M. Dettwyler 1 General Energy Research Department, Paul Scherrer Institut, 5232 Villigen, Switzerland 2 Kistler Intrumente AG, 8408 Winterthur, Switzerland The Large Engine Research Facility (LERF) is a new research platform realized within the Competence Center for Energy and Mobility (CCEM) at the Paul Scherrer Institute and is currently used – in close cooperation with industrial § and academic partners - within the Hercules- research program of the European Commission Framework Program FP7. The purpose of this facility is to develop new combustion management technology aimed at significantly reduc- ing the NOx production within the engine without compromising the engine efficiency or increasing the amounts of unburned hydrocarbons and particulate matter. Beginning with the groundbreaking for the new building in April 2008 the installation of the LERF at the PSI has been completed within 7 months and the first start was realized in October 2008. Introduction and Motivation absolute piezoresistive pressure sensors for refe- The purpose of this paper is to introduce the rencing purposes. Additionally we provide a port LERF and the associated research program. The for future optical sensors applications. Special care endeavor is driven by the increased demands for was taken to optimize sensor position for best the conservation of air quality put into legislation by measurement accuracy, sensor accessibility and the International Maritime Organization (IMO). To the minimization of dead volume. Furthermore, the meet these requirements of reducing NOx emis- intake and the exhaust manifold pressures are sions by about 80% within emission controlled accessible to absolute piezoresistive pressure areas by 2016 necessitates increased efforts to transducers. All high frequency signals are fed via identify the most promising techniques within strin- a front-end amplifier to a fast transient recorder gent budgetary boundary conditions. which is triggered by the free-end encoder. Besides the measurements of shaft power and Description of LERF indicated power, the engine is fully instrumented to The large engine research facility mainly com- obtain the flow of heat and energy in and out of the prises a Wärtsilä 6L20CR engine having a rated system, comprising air mass flow rate, fuel flow power of 1080 kW at nominal speed of 1000 RPM. rate, cooling water temperature differences and It is coupled to an electric generator which is flow rates. Additional measurements like charge air mounted on a common base frame. A frequency / temperature and pressure, exhaust gas tempera- voltage converter together with a transformer al- tures and turbocharger speeds etc. are directly lows loading the engine at variable speed while still obtained from the Engine Control Unit (ECU) via feeding the generated power synchronously to the TCP Modbus interface. medium voltage (16 kV) grid. For the exhaust gas composition analysis we The test stand control system is implemented use a FTIR spectrometer (AVL Sesam) capable of by AVL and allows three different control modes simultaneously measuring many exhaust species for the generator and engine respectively. (H2O, CO2, CO, NO, NO2, N2O and others) at a i) Torque / Speed rate of 1 Hz. ii) Speed / Power Additionally, for compliance with the Swiss fed- iii) Propeller Law / Speed eral air quality conservation regulation, we pro- The shaft power and engine speed is measured vided an exhaust gas after-treatment system using using a Kistler torque flange mounted in-between Vanadium based SCR with Urea as reducing the engine and the generator (Tmax= 15kNm and agent. Hall pickup 180 Cts/rev). Additionally a second encoder (Hübner POG-10DN-0900-TTL) is Current Work mounted on the free crank shaft end to ensure At this beginning stage of the project we are precise crank angle measurements which are es- working on obtaining baseline measurements for sential for reliable indication measurements. The the standard engine setup as delivered. To say, we cylinder head # 6 at the free end side is extensive- will establish the global energy balance, the tran- ly equipped using multiple sensor access ports for sient cylinder and inlet/outlet manifold pressures, simultaneous measurements. These ports are the exhaust gas composition for the nominal sta- tailored to hold a variety of sensors, e.g. piezoelec- tionary load steps. tric sensors for precise thermodynamic analysis or * Corresponding author: Klaus.Hoyer@psi.ch Towards Clean Diesel Engines, TCDE 2009 § Wärtsilä Corporation, ABB Turbo Systems, Kistler Instruments, and CCEM Partners These baseline measurements from the newly manufactured cylinder head will be used to support a cooperative effort with ETH Zürich and provide calibration data for numerical simulation. The first approach in reducing the NO x will be a combination of 2-stage turbo charging (TC) and Miller timing of the intake valves. Currently the assembly for the 2-stage TC sys- tem is being designed. In combination with the new charging system we will implement the variable inlet closure (VIC) system which allows control of the intake valve timing. This variability is especially important for engine start and partial loads, where the valve timing should stay unchanged with re- spect to the original engine setup. In a later stage, limited use of HFO is planned to see the influences of the heavier fuel composi- tion and sulfur on the combustion process espe- cially concerning the production of soot and parti- culate matter with the extreme Miller timing. Outlook [1] We anticipate achieving NOx reduction by more than 50% compared to the baseline mea- surements and will try to maximize the possibilities of the 2-stage TC / VVT combination. Challenges lie ahead resulting from the lower combustion tem- perature which will have a direct effect on the ex- haust gas composition but also will influence the operational envelope of the EG after-treatment. The dynamic response of the modified engine setup is also of great interest regarding load pickup for certification. References [1] C. Wik, B. Hallback, 'Utilisation of 2-stage turbo charging as an emission reduction means on a Wärtsilä 4-stroke medium-speed diesel engine’, th paper no. 101 , 25 CIMAC Congress, Vienna 2007