Dual Fuel System: Installation

OptiBlend® system engineers will work directly with you to size the system for your needs. This will ensure the system you receive will be ready for immediate installation. This article will briefly discuss the installation components and process you can expect from an OptiBlend® licensed installation technician.

The OptiBlend® system will be shipped to site with each assembly packaged together. The assemblies in the OptiBlend® kit typically include the following:

• Control Panel
• Cabinet mounting hardware
• Gas Train
• Gas Train mounting hardware
• Gas Train installation material
• Fuel Wye (dual bank only)
• L-Series Assembly (Gas control valve)
• Mixer Assembly
• Hose Kit (variable size)
• Vibration Transducer Kit
• Thermocouple Kit
• Power Transducer Kit
• Current Transformers (CT) (optional)
• Additional installation materials

Quantities depend on engine configuration (# of turbos, kW rating, cylinder banks, etc.).

Mixer Assembly

The mixers use the venturi effect to “pull” gas into the engine. You will need to determine the air intake diameter, outlet, and turbo inlet diameter to ensure the correct hose kit is packaged for your system installation. Please refer to your operation manual to locate these ports on your power generator.

Gas Train Assembly and Installation

The gas train supplies the engine with natural gas. It consists of a manual ball valve, gas filter, 24VDC normally closed solenoid, and zero-pressure regulator. The gas train is shipped assembled with the OptiBlend® kit. The inlet to the gas train is at the ball valve and can vary in size depending on the application but is most commonly 2” in diameter. The gas train may be mounted on or off the engine/generator skid. Before choosing a location for the gas train, consideration should be given to routing and requirements of the flexible fuel hoses to the mixer(s), vibration isolation, proximity to heat sources, and connection to gas supply piping.

Mixer / Fuel Hose and Reference Air Hose Installation

The mixer(s) and gas train(s) are connected with flexible fuel hose and reference air hose after installation. These are part of the gas train installation material kit. The kit includes appropriate materials based on engine configuration. The installation material includes the flexible fuel hose, reference air hose, hose clamps, hump hose (for supporting fuel wye or moving air cleaners) and an assortment of hardware. If the engine to be retrofitted has more than one turbo, then fuel tee(s) will be included with the OptiBlend® shipment. The fuel wye can be configured by the installer for specific packaging requirements.

Control Panel Installation

The control panel can be installed directly on the engine/generator skid, standalone, or suspended from the ceiling using “unistrut” type support structure. The cabinet has 4 fixed mounting tabs. Location of the panel should allow for easy access to the Emergency Stop switch, and dual fuel Enable switch. Consideration should also be given to the various distances to each engine/gas train sensor and routing requirements of the sensor wiring harnesses. The control panel should not be mounted in close proximity to hot engine surfaces such as exhaust manifolds or mufflers. If the control panel is mounted on the engine/generator skid, suitable vibration isolators should be used to protect the control panel from excessive vibration.

Wire Harness Installation

The OptiBlend® system comes with a single wire harness to connect the electrical devices. The wire harness includes connections for the L-Series throttle, solenoid, second gas train harness, control panel power and signal, 5V thermocouple power, CAN communication, power transducer, and vibration transducer.

Sensor Installation

Exhaust Gas Temperature Sensor

The exhaust gas temperature sensor is a type K thermocouple and is installed in the engine exhaust system. The thermocouple should be mounted in a position where it is exposed to exhaust gasses from all cylinders of a particular bank. Typical mounting locations include exhaust manifold, turbocharger exhaust outlet or exhaust collector pipe. If a particular bank has more than one turbo, thermocouples should be used for each turbo. In all cases, the thermocouple should be installed as close to the turbo(s) as possible and should not be installed downstream of the exhaust silencer.

XCAN Power Transducer

The XCAN and Eden Innovations LLC supplied CTs (Current Transformers) come with a complete plug-and-play harness. Ring terminals are connected to the harness for connection to the voltage bus bars.

Current Transformers (CT)

The current transformers supplied by Eden Innovations LLC are of split-core design for easy installation and shipped with shorting wires that must be removed to connect the power meter harness (also supplied by Eden Innovations LLC). Shorting wires protect the CTs in case they are installed with the leads open. Installation should be performed by a trained electrician following all proper safety precautions.

Electronic Vibration Transducer (Vibe Sensor)

The vibration transducer sends the current engine vibration level to the Programmable Logic Controller (PLC) which is programmed with a vibration vs. load curve. While running on dual fuel, engine vibration is typically less than running on diesel alone, however, in cases where there is too much gas, or the engine is running poorly (clogged air or fuel filters) vibration will increase.

Installation, System Configuration and Commissioning

An OptiBlend® licensed technician typically requires 2-3 days to complete physical installation of components, followed by commissioning the system.  Once all components are installed commissioning can begin. The major work of commissioning is setting the alarm limits and calibrating the fuel control valve. It is recommended that a load test of the engine be performed to verify that the engine performs according to specifications. This check should include all major engine systems (cooling, lubrication, fuel, charge-air cooling, air intake, safety, etc.) to ensure proper operation and condition. All outstanding maintenance and/or performance items should be addressed prior to running the engine in dual fuel mode.