Generator and Alternator

By Ship Electrical Engineer Ather Rizvi's Lecture on 

Generator and Alternator 

Fuel Lever Micro Switch on the governor (red in colour) is used to stop the generator from starting and stopping it in case of emergency. One of the few reasons for the generator not getting start is this lever being in the wrong position. It is one of the majour safties of the generator and has to be checked before the starting of the generator for its working.

Lube Oil cooler is used to maintain the temperature of the lube oil.
There are 4 different types of pressure switches

1. Lubeoil inlet low pressure Alarm.
2. Standby lubeoil inlet auto start.
3. Lubeoil inlet low pressure Switch.
4. Cool F.W. inlet low pressure Alarm.
5. Flywheel lever has two main functions.
6. To stop the generator in case of emergency.
7. Priming the genreator before starting or after changing the lube oil.

Drain tank is present on either side of the generator to accumulate the oil leaking from any part of the generator. It has a float switch which is responsible for intiating alarm when the tank is full.
Electrical Side of the Generator consists of Following parts:

1. Exciter
2. Alternator
3. Alternator is further devided into following parts:
4. Stator
5. Rotor
6. Diode
7. Armature
8. Heater to remove moisture and dampness from armature.
9. The control pannel consists of following main parts

A.C.B. (Air Circuit Breaker): Light of ACB turns on when the generator gets on load.
Bus Bars: Current generated enters the bus bars in three phases and then transmitted to the starter pannel. For a 3 phase generator there are 3 bus bars labled R, S, and T. In case of motor they are labled as U,V and W.

Reverse Power Relay: R.P.R. is used to prevent the generator converting into motor. It is tested by using synchronoscope. When two generators are run in parallel synchronoscope is used to synchronise their voltage, current and most importantly phase difference. For testing R.P.R. synchronometer is used to transmit voltage generated from say generator 1 to generator 2. If R.P.R. trips means that it is working properly. R.P.R. has a reset button which can be used to reset in case of a trip.

Synchronoscope: It is used to synchronise the phase difference and voltage developed by one or more generators in parallel. It is done by lowering the r.p.m using the governor and then synchronise the supply when the needle is at 0. In case of Auto it is all done by itself.

Voltage Regulator: It is used to increase or decrese the volatage to reach the desired amount. It can only increase or decrease small amount of voltage.

Preferential Trip: It is used to supply the current to the appliances.

Generator and its Parts.

By Chief Engineer Riaz Marghoob's Lecture On

Generator and its parts

It was the Daihatsu Generator.


There are two sides of the generator.
Electrical Side. (part after the flywheel)
Mechanical Side.

MECHANICAL SIDE
Cylinder Head is the top cover of the cylinder and contains following parts.
Rocker Arm.
Cylinder Relief Valve.
Exhaust Valve.
Air Starting Valve.
Fule injector.
Indicator Cock. (Indicates the inside position of the cylinder)
Push Rod
Turbo Charger is attached with the generator and is responsible for removing the burnt gasses from the cylinder and filling it with the fresh air. The more the fresh air in the cylinder the more will be the generator's efficiency.


Sump at the lower part of the engine contains lube oil for lubrication of Crank Pin Bering, main Bearing, cross head and Piston and cylinder liner.


There are two types of lubrication methods:
Splash Lubrication.
Forced Lubrication.

Splash Lubrication:

Splash lubrication takes place by the splashing due to the movement of the crank shaft.



Forced Lubrication:

For forced lubrication lube oil pump is required which pumps the lube oil through the connecting rod into the gudgeon pin hole through which it is released and lubricates the area between the piston and cylinder liner.



In both cases lube oil filter is attached to remove any impurity from the lube oil.


Fule pump is placed on the right hand side of the governor and is used to pump the fuel in the pipe over the cylinder head


Like a lube oil filter there is also a fuel oil filter which is used to filter the fuel oil.


Lube oil cooler is present to maintain the temperature of lube oil.


Piston contains two different types of ring attached in differnt combination depending upon the construct.
Compression Ring.
Scrapper Ring Or Oil Ring

Compression Ring:

It is used to restrict the hot gasses from entering into the sump.



Scrapper Ring:

It is responsible for creating a film of lube oil and scrap the lube oil into the sump from the liner.



Before attaching the ring make sure of the correct side of the ring to be at the top. Some times it is written on the ring "This Side Top."


Camshaft is present above the crank shaft and operates the rocker arms above the valve via push rod. It operates the push rod which further operates the rocker arm which further operates the spring loaded valves on cylinder head.

FOR ELECTRICAL SIDE PLEASE REFFER TO DOC. 1 ATHER RIZVI's LECTURE.

Written by Ali Ahmed

Ship demurrages: Pakistani oil tanker detained at Dubai

A Pakistani oil tanker is under arrest at a seaport in Dubai, it emerged on Saturday. A UAE court has ordered the arrest of a Pakistani oil tanker on the complaint of a Ukrainian shipping company. MT Lahore was detained at Fujairah Port of Dubai on Friday after a UAE court decreed in favour of M/s Vista Shipping claiming $20400 ship demurrages against Pakistan National Shipping Corporation (PNSC).

Chairman PNSC Arif Elahi confirmed the arrest saying the issue was a routine in shipping industry and would be resolved soon. “The vessel would be free by tomorrow (Sunday),” he told Business Recorder. The Ukrainian shippers, Elahi said, was using “pressure tactics” to press for its demurrage claims the amount of which was unknown to the PNSC chief.

Another official at the Corporation said M/s Vista Shipping had been demanding $204000 from the PNSC which in June last year had chartered the former”s oil tanker for the import of furnace oil to Pakistan. “Our estimates put the demurrage claims stand at not more than $186000,” said the official. He said his side had mobilised the P&I Club, an international insurance entity, to settle the dispute. The P&I-backed solution, he said, may required the PNSC to pay to the claimant around $210000, a sum higher than the Pakistani shipping authorities have so far resisting to pay.

MT Lahore was detailed after the company handed the Fujaira port operator what PNSC official said an “arrest warrant” issued by a UAE court. Officials at PNSC said, “Issue was disputable between the Corporation and M/s Vasta Shipping since June last year.” The sources privy to the matter said the Ukrainian firm had also approached the International Maritime Organisation through submitting an application to it. “PNSC would have to pay a Rs 1.7 million penalty till the clearance of demurrage,” they said.

PNSC has long been at loggerheads with Pakistan State Oil, the state-run oil importer, over what PSO claims, belated arrival of PNSC vessels to the required port. The PNSC denies it, as PSO claims to have incurred millions of dollars as demurrages because of PNSC”s belated provision of oil tankers. The PNSC official, when asked as to why the demurrage was caused at first place, said “you always have such claims in shipping business”.
Source: Business Recorder

Source: http://www.hellenicshippingnews.com

Fire on containership

Singapore(11 jul 2015): Japanese-built containership Kamala (24,724 dwt, built 1999) caught fire this morning around 400km off the coast of the Japanese island of Kuchinoshima in the East China Sea.


The vessel was headed to the Korean port of Ulsan, having departed Gresik in Indonesia, when it sent a distress signal this morning around 12:45am. Japan’s 10th Regional Coast Guard mobilised to assist, to find the vessel and several containers on fire.

According to Japanese media reports the vessel was carrying 796 containers, and as of noon today the fire had not been extinguished. No injuries were sustained by the 23 crew members, mostly from Thailand and India, although its not clear yet whether they have evacuated the vessel.


The vessel is being operated on a Korea-Indonesia service, users include Korean lines KMTC and Hanjin Shipping. The vessel is owned by Singapore-headquartered Seachange Maritime.

Mitsui tests first commercial model on HFO and methanol

Successful Demonstration of the ME-LGI Concept

Mitsui Engineering & Shipbuilding Co., Ltd. (MES)

The MAN Diesel & Turbo license

Recently demonstrated the liquid-gas-injection concept successfully in Japan. The successful demonstration took place on 17 June, 2015 using the very first ME-LGI engine to ever be commercially produced. The engine, with the type designation 7S50ME-B9.3-LGI, is bound for a vessel currently under construction by Minaminippon Shipbuilding Co., Ltd. for Mitsui O.S.K. Lines, Ltd.


A natural step

Ole Grøne, Senior Vice President – Low Speed Promotion & Sales – MAN Diesel & Turbo described the event as a significant milestone in the development of Diesel technology and said: “The immediate market acceptance of our ME-GI (Gas Injection) engine confirmed the growing demand for low-sulphur, non-HFO options in the face of increasingly stricter sulphur limits in fuel. In turn, extending our dual-fuel engine programme with an ME-LGI unit that can run on liquid fuels was therefore a natural step.”

He continued: “The interest in our ME-LGI engine confirms this dual-fuel, low-speed trend and will offer even more alternatives to HFO, which – apart from methanol – will include LPG, dimethyl ether (DME), and (bio-) ethanol, as well as several other, low-sulphur, low-flashpoint fuels.”

Grøne concluded: “We welcome our partners’ interest in our technology and acknowledge their taking the lead in proving the ME-LGI concept. We are confident that their faith will be rewarded in the immediate future.”


Demonstration

Mitsui’s ME-LGI demonstration involved four separate stages:
Change to methanol running.
Methanol running 50-75%.


Load variation.
Change to fuel-oil running.
The event took place at the company’s Tamano works, near Okayama in the western part of the mainland, and was witnessed by approximately 60 interested guests from the marine industry in Japan.

The ME-LGI concept is an entirely new concept that can be applied to all MAN Diesel & Turbo low-speed engines, either ordered as an original unit or through retrofitting. With two injection concepts, the ME-GI and the ME-LGI concept greatly expand the company’s dual-fuel portfolio and enables the exploitation of more low-flashpoint fuels such as methanol and LPG.

The engine’s ‘ME-’ prefix indicates that the new engine benefits from well-proven electronic controls that also encompass the fuel being injected by a so-called Fuel Booster Injection Valve. This innovative fuel booster, specially developed for the ME-LGI engine, ensures that a low-pressure, fuel-gas supply system can be employed, significantly reducing first-time costs and increasing reliability. The Fuel Booster Injection Valve will be introduced also on regular ME HFO engines, eventually.


MAN developed the ME-LGI engine in response to interest from the shipping world in operating on alternatives to heavy fuel oil. Methanol and LPG carriers have already operated at sea for many years and many more LPG tankers are currently being built as the global LPG infrastructure grows. With a viable, convenient and economic fuel already on-board, exploiting a fraction of the cargo to power a vessel makes sense with another important factor being the benefit to the environment. MAN Diesel & Turbo has previously stated that it is already working towards a Tier-III-compatible ME-LGI version.

The LGI combustion chamber consists of two LGI-fuel valves and two oil-fuel valves, the latter used for pilot oil when running in LGI-mode and as fuel valves when running in normal mode

The LGI parts, highlighted in yellow, are based on the familiar, proven ME-design