Sunday, September 21, 2008
Common rail diesel direct injection- to beat the high petroluem cost in the third world
In the USA, the ultimate fuel saver is the hybrid Toyota Prius, which sips fuel, the cost here is so high and the technology the technology of prius is not as supported as in US.
here saving fuel means LPG auto gas or CDRI
this is the actual photo of test drive. we are very disappointed about the actual real life consumption of the CRDI,
the two personnel in blue work suits are from Hyundai Shaw, they prep the accent for the 100km trip and check the computer in the engines
at the pump is Hyundai engineer personally supervising the filling up of the fuel tank, Hyundai only uses shell products
This is a Hyundai accent a crdi diesel, we are so amazed by the claim of Hyundai at it could have a mileage of 36 km per liter as claimed my several magazines and motoring authors, we dared the technical men of HARI Hyundai motors Philippines to personally supervise the test run, it did pass at highway driving from edsa to San Simon and vv. but it has to have the ff parameters
1. 100 km run
2. fuel to the brim
3. maximum of 80 km per hour, ave 65 kph on nlex
4. does not exceed 2000 rpm
in the city driving it is 10.5km per liter
over all, the fuel economy is normal, nothing outstanding, but what make me feel good about Hyundai is their resilience that the Accent is an above average economy car, they cannot accept that this has a real world economy of 11 km per literCommon rail direct fuel injection is a modern variant of direct fuel injection system for petrol and diesel engines.
On diesel engines, it features a high-pressure (over 1,000 bar/15,000 psi) fuel rail feeding individual solenoid valves, as opposed to low-pressure fuel pump feeding unit injectors (Pumpe Düse or pump nozzles). Third-generation common rail diesels now feature piezoelectric injectors for increased precision, with fuel pressures up to 1,800 bars (26,000 psi).
Today the common rail system has brought about a revolution in diesel engine technology. Robert Bosch GmbH, Delphi Automotive Systems, Denso Corporation, and Siemens VDO (now owned by Continental AG) are the main suppliers of modern common rail systems. The car makers refer to their common rail engines by their own brand names:
BMW's D-engines (also used in the Land Rover Freelander TD4)
Cummins and Scania's XPI (Developed under joint venture)
Cummins CCR (Cummins pump with Bosch Injectors)
Daimler's CDI (and on Chrysler's Jeep vehicles simply as CRD)
Fiat Group's (Fiat, Alfa Romeo and Lancia) JTD (also branded as MultiJet, JTDm, Ecotec CDTi, TiD, TTiD , DDiS, Quadra-Jet)
Ford Motor Company's TDCi Duratorq and Powerstroke
General Motors Opel/Vauxhall CDTi (manufactured by Fiat and GM Daewoo) and DTi (Isuzu)
General Motors Daewoo/Chevrolet VCDi (licensed from VM Motori; also branded as Ecotec CDTi)
Land Rover's "Storm" TD5 derived from the Rover L-Series engine
Mazda's CiTD (1.4 MZ-CD, 1.6 MZ-CD manufactured by Ford)
Mitsubishi's DI-D (recently developed 4N1 engine family uses next generation 200 MPa (2000 bar) injection system))
PSA Peugeot Citroën's HDI or HDi (1.4HDI, 1.6 HDI, 2.0 HDI, 2.2 HDI and V6 HDI developed under joint venture with Ford)
SsangYong's XDi (most of these engines are manufactured by Daimler AG)
Subaru's Legacy TD (as of Jan 2008)
Volkswagen Group: The 4.2 V8 TDI and the latest 2.7 and 3.0 TDI (V6) engines featured on current Audi models use common rail, as opposed to the earlier unit injector engines. The 2.0 TDI in the Volkswagen Tiguan SUV uses common rail, as does the 2008 model Audi A4. Volkswagen Group has announced that the 2.0 TDI (common rail) engine will be available for Volkswagen Passat as well as the 2009 Volkswagen Jetta.
Volvo 2.4D and D5 engines (1.6D, 2.0D manufactured by Ford)
Solenoid or piezoelectric valves make possible fine electronic control over the fuel injection time and quantity, and the higher pressure that the common rail technology makes available provides better fuel atomisation. In order to lower engine noise the engine's electronic control unit can inject a small amount of diesel just before the main injection event ("pilot" injection), thus reducing its explosiveness and vibration, as well as optimising injection timing and quantity for variations in fuel quality, cold starting, and so on. Some advanced common rail fuel systems perform as many as five injections per stroke.
Common rail engines require no heating up time and produce lower engine noise and emissions than older systems.
Diesel engines have historically used various forms of fuel injection. Two common types include the unit injection system and the distributor/inline pump systems (See diesel engine and unit injector for more information). While these older systems provided accurate fuel quantity and injection timing control they were limited by several factors:
They were cam driven and injection pressure was proportional to engine speed. This typically meant that the highest injection pressure could only be achieved at the highest engine speed and the maximum achievable injection pressure decreased as engine speed decreased. This relationship is true with all pumps, even those used on common rail systems; with the unit or distributor systems, however, the injection pressure is tied to the instantaneous pressure of a single pumping event with no accumulator and thus the relationship is more prominent and troublesome.
They were limited on the number of and timing of injection events that could be commanded during a single combustion event. While multiple injection events is possible with these older systems, it is much more difficult and costly to achieve.
For the typical distributor/inline system the start of injection occurred at a pre-determined pressure (often referred to as: pop pressure) and ended at a pre-determined pressure. This characteristic results from "dummy" injectors in the cylinder head which opened and closed at pressures determined by the spring preload applied to the plunger in the injector. Once the pressure in the injector reached a pre-determined level, the plunger would lift and injection would start.
In common rail systems a high pressure pump stores a reservoir of fuel at high pressure — up to and above 2,000 bars (29,000 psi). The term "common rail" refers to the fact that all of the fuel injectors are supplied by a common fuel rail which is nothing more than a pressure accumulator where the fuel is stored at high pressure. This accumulator supplies multiple fuel injectors with high pressure fuel. This simplifies the purpose of the high pressure pump in that it only has to maintain a commanded pressure at a target (either mechanically or electronically controlled). The fuel injectors are typically ECU-controlled. When the fuel injectors are electrically activated a hydraulic valve (consisting of a nozzle and plunger) is mechanically or hydraulically opened and fuel is sprayed into the cylinders at the desired pressure. Since the fuel pressure energy is stored remotely and the injectors are electrically actuated the injection pressure at the start and end of injection is very near the pressure in the accumulator (rail), thus producing a square injection rate. If the accumulator, pump, and plumbing are sized properly, the injection pressure and rate will be the same for each
In petrol engines, it is utilised in gasoline direct injection engine technology