3. steam plant & boiler31!12!09
DESCRIPTION
boilerTRANSCRIPT
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 1
To Be A Leader In Maritime Education & Training
Steam Turbines
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 2
To Be A Leader In Maritime Education & Training
Steam plant - content
Describe Steam plant layout & function
Describe Turbine operation- impulse & reaction
Describe Pressure & velocity compounding
Describe Boiler construction & mountings
Describe procedure to warm-up boiler
Describe steam plant preparation procedures.
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 3
To Be A Leader In Maritime Education & Training
Steam Turbines
Function :- Convert steam energy into mechanical work.
Advantages: Low machinery weight.
Low maintenance cost.
Low vibration.
Minimum space required
Disadvantage: High fuel consumption compared to diesel
engine. ( about 300 g / KWh vs 180 g/ KWh)3
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 4
To Be A Leader In Maritime Education & Training
Steam Plant Layout
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 5
To Be A Leader In Maritime Education & Training
Layout of Steam Propulsion Plant
Steam from the boiler is superheated before it is supplied to the high pressure (HP) and low pressure (LP) turbine during ahead operation.
Astern manoevring valve is opened only for astern operation of the astern turbine.
Waste steam from the turbine is cooled by sea water and condensed to water in the condenser.
Condensate pump transfer the water to de-aerator where air is removed from the condensate water.
Main feed pump transfer the water to heaters and economiser for heating before it is sent to the boiler
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 6
To Be A Leader In Maritime Education & Training
Cross - Compound
It is used to describe a steam turbine unit made up of a high pressure and a low pressure turbine.
This is the usual main propulsion turbine arrangement.
The alternative is a single cylinder unit which would be usual for turbo-generator sets.
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 7
To Be A Leader In Maritime Education & Training
Impulse Turbine De Laval
Steam supplied to a nozzle box and through the nozzle box to a group of nozzles.
Steam expands in passing through the nozzles with a fall in pressure and gain in velocity.
The high velocity steam jet is angled and directed to enters rows of blades without shock.
The change of momentum produces a force tangential to blades and a turning moment to rotor spindle.
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 8
To Be A Leader In Maritime Education & Training
De Laval Impulse Turbine
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 9
To Be A Leader In Maritime Education & Training
Reaction Turbine
One stage consists of fixed blades acting as nozzles followed by a row of moving blades fixed on rotor.
Pressure drops equally while the steam passes on fixed blades and moving blades.
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 10
To Be A Leader In Maritime Education & Training
Reaction Turbine
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 11
To Be A Leader In Maritime Education & Training
Reaction Turbine
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 12
To Be A Leader In Maritime Education & Training
Parsons Reaction Turbine
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 13
To Be A Leader In Maritime Education & Training
MAIN TURBINE
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 14
To Be A Leader In Maritime Education & Training
TURBINE FOR GENERATOR
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 15
To Be A Leader In Maritime Education & Training
TURBINE SIDE
GENERATOR
REDUCTION
GEAR
WHY?
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 16
To Be A Leader In Maritime Education & Training
Compounding of Turbine
The pressure or velocity drop or both takes place in a controlled manner in a number of successive steps or stages.
The turbine becomes long but efficient and practicable.
(Compounding overcome high energy of steam liberated which is practically impossible to utilise)
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 17
To Be A Leader In Maritime Education & Training
Pressure Compounded Impulse
Turbine Made up of large number of stages.
Each stage consists of a row of nozzles followed by a row of moving blades attached to the wheel of the rotor.
Each stage has the same pressure but the pressure varies in successive stages.
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 18
To Be A Leader In Maritime Education & Training
Pressure Compounded Impulse
Turbine
Advantages:
Steam velocity lower due to smaller heat drop
Efficiency increased
Disadvantages:
Increase in first cost
Increase in length
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 19
To Be A Leader In Maritime Education & Training
Pressure Compounded Impulse Turbine
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 20
To Be A Leader In Maritime Education & Training
Velocity Compounded Turbine
Consists of a row of nozzles in which all the pressure drop takes place followed by alternate rows of moving and fixed blades.
Pressure remains uniform through the stage but velocity drops.
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 21
To Be A Leader In Maritime Education & Training
Velocity Compounded Turbine
Advantages:
Large pressure drop obtained through the nozzle smaller heat drop
Reduction in turbine length
Reduction in costs less materials required
Disadvantages:
Low efficiency
Increase steam consumption
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 22
To Be A Leader In Maritime Education & Training
Velocity Compounded Impulse Turbine
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 23
To Be A Leader In Maritime Education & Training
Akademi Laut Malaysia Malaysian Maritime Academy
Compounding for Pressure and
Velocity Suitable for High Pressure (HP) turbine. Steam expended through a set of nozzles.
The first stage is velocity compounded through two or three rows of moving blades.
Steam now enters the second row of nozzles, expanded to lower pressure and passed on to successive stages.
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 24
To Be A Leader In Maritime Education & Training
Compounding for Pressure and Velocity
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 25
To Be A Leader In Maritime Education & Training
Fundamentals of steam generation
Boiling point of water depends strictly upon the pressure exerted on it:
Pressure (bar) 10 20 100
Boiling Point (0C) 180 212 311
The saturated steam at 100 bar, 311 0C , when subjected to further heating will increase the dryness of the steam but does not increase its temperature
If steam flow passes out of the boiler to externally heated elements, its temperature can be increased and the steam becomes superheated
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 26
To Be A Leader In Maritime Education & Training
Foster Wheeler D type water Tube boiler
Consists of two horizontal cylindrical drums.
* Top steam and water drum
(referred as steam drum)
* Bottom water drum
The drums are connected directly by vertical generating tubes and by other tubes via headers.
One set of tubes from steam drum are bent to form part of roof of combustion chamber and lower portion forms the side walls.
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 27
To Be A Leader In Maritime Education & Training
Water Tube Boiler
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 28
To Be A Leader In Maritime Education & Training
Water Tube Boiler
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 29
To Be A Leader In Maritime Education & Training
Boiler Mountings
Main and Auxiliary Steam Stop Valve Steam outlet
Main and Auxiliary Feed Check Valve water inlet
Feed Water Regulator regulate water to boiler
Water Gauges indicate water level
Pressure Gauge Cock steam to pressure gauge
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 30
To Be A Leader In Maritime Education & Training
Boiler Mountings
Safety Valve release excessive pressure
Blow Down Valve remove dissolved contaminants
Scum Valve- remove surface contaminants
Salinometer Cock sample water for test
Air Cock release air in system
Soot Blower remove soot/carbon from boiler tubes
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 31
To Be A Leader In Maritime Education & Training
Regenerative Condenser
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 32
To Be A Leader In Maritime Education & Training
Closed Feed System
Feed water circuit from condenser to boiler is completely closed.
Main function is to prevent the condensate from contact with atmospheric air before entry boiler.
The de-aerated water would absorb air if any part of circuit was open to atmosphere.
In regenerative condenser, the air is taken out separately to the condensed water.
The air is extracted by a steam jet air ejector.
The water is taken out by a condensate pump.
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 33
To Be A Leader In Maritime Education & Training
Closed Feed System
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 34
To Be A Leader In Maritime Education & Training
Procedure for Raising Steam
Water in boiler and at correct level.
Air to burners and furnace for combustion and purging.
Fuel supply adequate and at correct pressure and temperature.
Means of ignition.
Light the burner.
Steam flow at correct pressure and signal is used to vary the firing rate as the demand requires.
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 35
To Be A Leader In Maritime Education & Training
Warming through Steam Turbine
Turbine must be thoroughly heated up as near as possible to working temperature before starting.
Assuming auxiliary steam line is already in use:
All drains on engine and main steam line open.
Start all lubricating pumps, check oil pressure at brgs. etc
Open main injection and discharge valves and start main condenser circulation pump.
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 36
To Be A Leader In Maritime Education & Training
Warming through steam turbine
Run condenser extraction pump to maintain low vacuum of about 200 mmHg
Change over auxiliary exhaust from auxiliary condenser to main condenser.
See the propeller is clear and turn the engine a little then take out the turning gear.
Ease main steam valve off its face to allow steam into main steam pipe.
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 37
To Be A Leader In Maritime Education & Training
Warming through Steam Turbine
Check the drain until water is driven out , open the steam valve very slowly and closed when the drains are blowing freely.
Check there is no obstruction to sliding feet and take expansion readings.
Put on gland steam and crack open
manoeuvring valves to allow a little steam into
engine.
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 38
To Be A Leader In Maritime Education & Training
Warming through Steam Turbine
After about 3 hours, raise vacuum to about 350 mmHg .
Operate manoeuvring valve carefully to slowly turn the engine a few revolutions ahead and then astern.
Repeat this operation about every 10 15 minutes for the next 2 hours.
At ready for stand-by, after 4 hours of heating up, pumps are brought up to normal speed, vacuum lifted up and expansion readings checked.
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 39
To Be A Leader In Maritime Education & Training
Manoeuvring of Steam Turbine
During manoeuvring , turbine drains are regulated as required and shut off at full-away.
Once warm through, turbine rotor must not remain stationary more than a few minutes at a time.
The rotor need to be rotated regularly to prevent failure from sag and distortion.
Astern running should be limited to prevent temperature rise, noise levels ,bearing overheating etc
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 40
To Be A Leader In Maritime Education & Training
y
Turbine Nozzles and Turbine Control
Nozzles serve to convert the high pressure and energy of the steam into a high velocity jet of steam with reduced pressure and energy content.
Steam inlet nozzles are arranged in several groups with all but the main group having control valves.
The power produced by the turbine can be varied, depending on how many nozzle valves are opened .
Valves admitting steam to turbine are called manoeuvring valves i.e ahead, astern and guardian valve
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 41
To Be A Leader In Maritime Education & Training
Akademi Laut Malaysia Malaysian Maritime Academy
Turbine Nozzles and Turbine Control
Guardian valve is an astern steam isolating valve.
Speed sensitive control device acts on ahead manoeuvring valve to hold the turbine speed constant at desired value.
Manoeuvring revolutions are usually about 80 % of the full away or full speed condition.
Once full away command received, turbine can gradually be brought up to full power operation.
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 42
To Be A Leader In Maritime Education & Training
Full Away - Steam Turbine
This operation will take about 1-2 hours.
This involves bringing into use turbo-alternators which use steam removed or bled at some stage from main turbine
Check expansion arrangement, drains shut, astern steam valve shut, condensate re-circulation valve after air ejector shut.
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 43
To Be A Leader In Maritime Education & Training
Emergency Astern Operation
Safe operating procedures must be ignored.
Ahead steam shut off, may be by an emergency trip, and astern steam valve is partly opened to admit steam gradually.
The turbine can be brought quickly to stopped condition and if required operated astern.
The stopping of the turbine or astern operation will occur about 10-15 minutes.
The use of emergency procedures can lead to serious damage to turbine, gearing and boiler.
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 44
To Be A Leader In Maritime Education & Training
Turbine Protection
Emergency self closing stop valve close automatically and shut off steam supply to turbine as a result of the following faults:a. loss of lubricating oil pressure
b. turbine overspeed
c. emergency stop
d. low condenser vacuum
e. high or low boiler water level
f. high condensate water level in condenser
Alarms - turning gear in (turbine cannot start)
- main thrust bearing wear down.
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 45
To Be A Leader In Maritime Education & Training
Main steam plant
Q & A session
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 46
To Be A Leader In Maritime Education & Training
Auxiliary boilers - content
1 Types of boilers
Water tube vs fire tube
2
Boiler construction & mountings
Fuel oil burning installation
3
Feedwater system
Procedures related to steam plant
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 47
To Be A Leader In Maritime Education & Training
Boiler
Two distinct types used on board:
(a) Fire Tube or Smoke Tube Boiler
(b) Water Tube Boiler
Fire Tube Boiler
Hot gases from furnace pass through the tubes while the water is on the outside.
Water Tube Boiler
Water flows through the inside of tubes while the hot furnace gases pass around the outside.
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 48
To Be A Leader In Maritime Education & Training
Boiler
Groups of Boiler
Main Boiler
Supply steam directly for main propulsion purposes
Auxiliary Boiler
Supply steam for auxiliaries which are essential for main propulsion e.g. fuel tank heating, main engine warming up, purifier heating etc.
Donkey Boiler
Supply steam for hotel and port services.
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 49
To Be A Leader In Maritime Education & Training
Composite Boiler
Often fitted where the generation of steam can be maintained by oil firing when the exhaust gas temperature falls e.g. engine stopped
Separate uptakes are provided for:
* the engine exhaust and
* the products of combustion from oil fire
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 50
To Be A Leader In Maritime Education & Training
Composite Boiler
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 51
To Be A Leader In Maritime Education & Training
Exhaust Gas Boiler
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 52
To Be A Leader In Maritime Education & Training
Boiler Fuel Oil Supply System
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 53
To Be A Leader In Maritime Education & Training
Contamination of Feed Water
1. Dissolved Salt (calcium & magnesium make water hard, other salt may produce acid and attack metal )
2. Oil (from leakages of oil tank heating coil form scum on water surface - cause priming of water )
3. Dissolved Gases (oxygen causes corrosion of boiler)
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 54
To Be A Leader In Maritime Education & Training
Contamination of Feed Water
Remedies
Blow- down ( surface and bottom)
Chemical Treatment
No leakage in system
Note: Carry over of water with steam due to priming result in Damage to valve , pump and turbine.
-
D1MC Semester 2 / Ship Stability / March 2007/LSC /STEAM PLANT 55
To Be A Leader In Maritime Education & Training
Auxiliary boilers
Q & A session