Man b&w me lgip dual fuel engines. - working. - safety devices/controls - lpg fuel pressure for injection. - safety for gas leakage. - hc sensors - alarm and shut down limits. - lpg fuel supply system from deck to me.
Working Principles " Fuel Flexibility: The MAN B&W ME-LGIP engine stands out as a dual-fuel engine capable of operating on both conventional fuels like Very Low Sulphur Fuel Oil (VLSFO) and Liquefied Petroleum Gas (LPG). This flexibility allows ship operators to comply with SOx regulations while maintaining operational efficiency.
" Diesel Principle: The engine uses the diesel principle, which ensures high operational stability and efficiency, even during load changes and fuel switchovers. This design allows a stable transition between fuel types without compromising performance.
" FBIV Technology: The engine incorporates a Fuel Booster Injection Valve (FBIV) system, which is essential for injecting LPG into the combustion chamber. This innovative fuel booster ensures that a low-pressure fuel-gas supply system can be used, which significantly reduces initial costs and increases reliability. The injection pressure ranges from 500 to 600 bar.
" Pilot Injection: LPG cannot ignite by itself in the combustion chamber, so a pilot injection of diesel or heavy fuel oil is required. This pilot injection is provided by conventional fuel valves and is crucial for igniting the gas mixture in dual-fuel mode. Safety Devices and Controls
" Double-Wall Piping: All supply and return pipes for each cylinder feature a double-wall pipe design. This design ensures that there are no exposed gas pipes in the engine room, as everything is contained within a ventilated double pipe.
" Gas Leakage Detection: Hydrocarbon (HC) sensors are installed to monitor the air within the double-wall gas pipes. These sensors can detect any gas leakage, triggering alarms and switching the engine to fuel oil operation.
" Inert Gas System: The engine includes an inert gas system for purging the gas system. This system is used during maintenance or when changing operations to prevent potential hazards.
" Sealing Oil System: A sealing oil system prevents gas from entering the control oil systems. The sealing oil is maintained at a pressure higher than the gas pressure, ensuring that no gas leaks into sensitive areas.
" GI Control and Safety System: The GI control and safety system is designed to fail safely. Any failures detected during gas operation will cause an automatic switch to HFO mode without any power loss. LPG Fuel Pressure for Injection
" Supply Pressure: The LPG supply pressure to the engine is maintained at 50 bar. However, the injection pressure in the combustion chamber ranges from 500 to 600 bar, achieved through the Fuel Booster Injection Valve (FBIV). Safety for Gas Leakage
" Ventilation Systems: The double-wall piping includes mechanical ventilation to ensure that any leaked gas is safely exhausted away from hazardous areas.
" Hydrocarbon Sensors: Hydrocarbon sensors are strategically placed within the double-wall piping system to detect any leakage. If hydrocarbon levels exceed safe thresholds, the system triggers alarms and initiates safety measures. Hydrocarbon Sensors and Alarm Limits
" Sensor Monitoring: Hydrocarbon sensors continuously monitor the hydrocarbon content in the air within the double-wall gas pipes.
" Alarm and Shutdown: If a gas leak is detected, the system responds by shutting down the gas supply and switching to fuel oil operation. The GI control system ensures that any failure detected during gas operation results in a safe switch to HFO mode without power loss. LPG Fuel Supply System from Deck to Main Engine
" System Components: The LPG supply system includes service tanks, low-pressure (LP) and high-pressure (HP) pumps, and a heating/cooling system to maintain the LPG at the required temperature and pressure.
" Double-Wall Design: The supply pipes use a double-wall design with double-ventilated pipes to prevent gas leaks in the engine room.
" Block and Bleed System: The system includes a block and bleed system to fully isolate the supply system from the main engine when needed. This involves closing specific valves to isolate the supply system and opening a vent to ensure complete isolation.
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