Gas Engines
Bi-Fuel System
Overview
Applications & Key Technologies
Gaseous Fuel System™
Overview
Gas Operating Characteristics
Gas Supply
Gas Control Components
Gas Installation
Gas Commissioning
Gas Products
Fuel Savings Calculation
Glossary
Conversion
(On this page...)
Bi-Fuel Systems
Applications
Key Technologies
Users
Benefits
OH-1 Control System Features
OH-1 Components
Ignition Control Module
High Pressure Gas Regulator
Gas Temperature Control
Fuel Metering Valve
Drive-by-Wire Throttle
Wastegate Control Valve
|
Bi-Fuel System
Applications(Gas Fuel System) OH-1 control system is designed to control heavy-duty, lean-burn
natural gas engines in urban buses and trucks and other alternative-fueled
on-highway vehicles. The highly accurate closed-loop control system helps OEMs
meet legislated emission levels, while maintaining diesel-like drivability and
excellent fuel economy.
Click to view larger image
Key Technologies
This system is based on key technologies not available in other control
systems on the market.
High Accuracy, Closed-Loop, Lean-Burn Control Strategy results from using
proprietary digital electronics and software technology that overcome the
difficulties encountered with wide-range oxygen sensors (UEGO) in other systems
available today.
Full-Authority Drive-by-Wire Strategy is made possible by combining Woodward's
Flo-Tech throttle and electronic wastegate
actuator designs with advanced load control technologies that provide unmatched
fuel economy, excellent vehicle drivability, and engine protection from turbo-overspeed
and engine overboost conditions.
Amongst the features are:
- Precise Open-Loop, Fuel Control Strategy
This strategy combines additional key sensors and control algorithm technologies
that improve the accuracy of volumetric efficient calculations. It also includes
advanced manifold filling calculations for handling large transient speed and
load changes that must be accommodated in heavy-duty, leanburn, spark-ignited
gas engine control systems.
- Advanced Diagnostic Features
A powerful tool for development engineers, as
well as field technicians, when diagnosing engine or vehicle problems.
- Model-Based Control Strategy
This strategy is used to compare actual engine operation with
expected values.
Users
Urban buses & trucks
Other alternatively-fueled on-highway vehicles
Benefits
Helps meet legislated emission levels
Improves fuel economy
Diesel-like drivability
Proven system
Flexible configurations (Complete system/Component)
Complete systems engineering services
Global engineering and service support
Gas Trains
OH-1 CONTROL SYSTEM FEATURES
 
 
Closed-loop, lean-burn, fuel control with adaptive-learn technology
Fully-integrated, wide range oxygen sensor for precise fuel/air ratio control
Speed-density control strategy with advanced transient compensation
Improved transient fuel/air ratio tracking and durability over most mass-air flow based systems
Electronic "Delta-P" wastegate control for improved thermal efficiency, torque rise, and drivability
High-energy inductive ignition system; up to 6 individual or double-ended coils
Full-authority drive-by-wire throttle system with min/max governing or all-speed governing
Idle-speed control includes speed set-point modifications for coolant
temperature, time from start, external fastidle switch, and other inputs
Max. governor uses programmable artificial droop for improved drivability
High altitude turbocharger overspeed protection
Constant-power and boost-derate features with inlet air and engine coolant
temperature compensated boost control
Advanced "turbo-lag" compensation for improved turbocharger response and
drivability
Deceleration/motoring fuel shut-off for improved thermal efficiency and
emissions
Electronic throttle-body
Multiple diagnostic and vehicle serial links available, including SAE
J1708/J1587, ISO-K, RS-232 hardware interface and several protocol
specifications
Over 100 individual diagnostic codes capable of detecting functional faults,
intermittent faults, sensor and actuator failures, and engine protection
problems
Malfunction indicator lamp (MIL) with field-extractable fault code feature
Extensive engine protection features including limp-home and derate modes for
inlet air temperature, engine coolant temperature, oil pressure, overboost, and
overspeed
Fail-safe limp-home feature for all sensor failure modes; the only exception
is the speed sensor which may be made redundant if desired
Knock sensing for real-time adjustment of ignition timing and boost/torque for
engine protection
OH-1 COMPONENTS
ECM-Eengine Control Module
Flash programmable module
8.2 volts compatible
Supports J1708/1587, ISO-K, RS-232
Built-in digital electronics for NGK UEGO sensor 60 pin I/O
ICM-Ignition Control Module
Inductive ignition On-engine mount
6 cylinder coil per plug/12 cylinders waste spark
12 or 24 volt versions
Simple digital trigger/reset function for coil dwell (timing control)
Ignition primary monitoring function
High Pressure Gas Shutoff Valve 12 or 24 volt versions
Pilot operated valve
SAE o-ring gas fittings
High Pressure Gas Regulator
Single-stage regulation 0 bar to 8 bar MAP/boost bias port
Tank pressure port for sensor mounting SAE o-ring gas fittings
Integrated PRD
Heat Exchanger and Gas Thermostat Low Pressure Gas Temperature Control
Optimizes gas density delivered to FMV Thermostat measures gas temperature
directly
FMV-Fuel Metering Valve
Single-point metering
On-engine mount
Bosch or Servo-Jet CNG/LNG injectors depending on application
8 or 12 injectors depending on engine power
Integrated positive fuel shutoff
Integrated gas pressure and temperature sensors
Flo-Tech Integrated Drive-by-Wire Throttle 8.2 Volt Compatibility
48, 60, and 68 mm throttle bore sizes
Flow shaping for improved idle control
Simple PWM, 0-5V, 4-20 mA, or 200 mA control signal
Wastegate Control Valve 12 or 24 Volt Versions
Digital valve provides air pressure to wastegate actuator
Vehicle supply or boost air
Technical Manuals 26220 (Calibration) 26221 (Systems)
|