The 4T50ME-GI Test Engine at MAN Diesel & Turbo's ... - Sae.org

More documents

Recommendations

Info

Fig. 12: Example of cryogenic tank design Cryogenic storage tank: The cryogenic storage tank is designed as an inner, stainless-steel vessel within an outer steel vessel. A vacuum is ap- plied between the vessels to provide sufficient insulation such that it can withstand temperature increases over a longer period of time (up to four weeks, depending on tank pressure). The tank pressure could be 2 to 2.5 bar, depending on the cryogenic-pump suction- pressure requirements. The cryogenic tank is equipped with safety valves with an opening pressure depending on design layout. The cryogenic tank is supplied with LNG delivered by a lorry tanker. Cryogenic reciprocating pump: The cryogenic reciprocating pump is supplied with LNG from a storage tank connected by a vacuum-insulated pipe, ensuring the supply of liquefied gas. The cryogenic pump could be an vacuum- insulated piston-pump type coupled to a variable-speed motor suitable for con- tinuous operation as well as cold stand- by. A suction filter is integrated into the pump head. The cryogenic-pump pressure and flow is controlled by the variable-frequency pump motor. The pressure set-point is taken from the ME-GI control system with a range from 150 to 300 bar. The cryogenic pump must be equipped with a pulsation damper in order to achieve gas-pressure fluctua- tions within 0.3 bar. Fig. 13: Gas train 15 The 4T50ME-GI Test Engine at MAN Diesel & Turbo’s Copenhagen Test Centre Vaporiser and glycol water heating system: The vaporiser is connected to the cryogenic-pump outlet and the LNG is heated with a glycol-water system. Alternative heating medias as engine- cooling water or ambient-temperature vaporisers could be utilised, but a glycol-water heating system is considered to be more temperature-consistent. The
Fig. 14: Arrangement of double-wall piping in ventilation system glycol-water flow is constant and inde- pendent of the LNG flow rate. The vaporiser-gas outlet temperature (45 °C) is controlled by the glycol-water temperature set-point. Gas-pressure control: The cryogenic pump is equipped with a discharge control valve. When the discharge control valve is open, gas flows to the vaporiser. If the gas pressure from the vaporiser outlet is higher than the gas pressure set-point from the GECU (ME-GI engine control system), the cryogenic-pump speed is decreased. If the cryogenic-pump speed reaches the minimum speed, a control valve opens to the venting mast. Gas train The gas is supplied from the vaporiser outlet through a single-wall, high-pressure pipe to the gas train, installed out- side the engine room, consisting of two block valves and one bleed valve (see Fig. 13). The volume between the block and bleed valves is depressurised while the gas system is out of operation (block valves are closed and bleed valve open). This is a safety arrangement in MAN B&W Diesel order to ensure that no gas can unin- tentionally be supplied to the engine. A valve-leakage test is automatically con- ducted before gas operation based on the pressure-drop over time. Double-wall gas pipes From the gas train, the gas enters the engine room and from here the gas is supplied courtesy of a double-wall piping system. These are, according to IMO guidelines, “gas-safe machinery spaces” where the engine room is main- tained as an ordinary engine room and not a hazardous area. The space between the inner, high-pressure pipe and the outer pipe is continuously ventilated – approximately 30 air changes per hour – by a mechanical ventilator made of spark-free fan material, installed out- side the engine room. The double-wall inlet must be supplied from a gas-safe area. In the event of a gas leakage from pipe rupture or sealing failure, the leakage is detected with a HC sensor installed in the ventilation-pipe outlet. The double-wall piping should be arranged as shown in Fig. 14. The double wall ventilation system is also part of the engine internal gas system and every valve, gas injection valves and high pressure sealings are connected to this system. The high pressure outlet from the engine will have to be connected with a silencer of sufficient capacity – see Fig. 15. Fig. 15: The high-pressure engine outlet needs to be connected with a silencer of sufficient capacity The 4T50ME-GI Test Engine at MAN Diesel & Turbo’s Copenhagen Test Centre 16
Page 1: The 4T50ME-GI Test Engine at MAN Di
Page 5 and 6: The 4T50ME-GI Test Engine at MAN Di
Page 7 and 8: eliability while the large volume o
Page 9 and 10: 4 ME-GI Concept and Engine Design D
Page 11 and 12: Gas block ELGI valve Purge & blow-o
Page 13: 5 ME-GI gas supply system This is a
Page 17 and 18: 7 Potential Applications for ME-GI
Page 19 and 20: MAN B&W Diesel The 4T50ME-GI Test E
Page 21: MAN Diesel & Turbo Teglholmsgade 41

The 4T50ME-GI Test Engine at MAN Diesel & Turbo's ... - Sae.org

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?