Course Topics
- General considerations for design of boilers
- Heat Transfer and properties of fluid
- Heat Transfer and Steam Generation
- Thermodynamics of steam generation
- Steam Engine Thermodynamic Cycles
- Modern day steam plants and machinery
- Marine applications of Boilers and Turbines
- Stresses in boiler shell
- Boiler pressure parts and effect of tempera
- Classification society requirements.
- Requirement of auxiliary boiler onboard
- Average working pressure of saturated steam boiler
- Condensate Systems
- Condensers
- Types of Condensers
- Constructional Details
- Location and Working Principles
- Contraction and Expansion Allowance
- Condenser Cooling Water Circulation
- Leakage Detection and Tube pluggin
- Condenser Tube Failures
- Performance check of a Condenser
- Condenser Materials
- Effect of Change of Temperature
- Change of Main Engine Power
- Condenser Surface
- Condensate Retum System
- Smoke Tube boilers
- General arrangement, flow of hot gases
- Vertical smoke tube boilers
- Cochran Spheroid Boiler
- Aalborg Mission OM boilers
- Sunrod Oil Fired Boiler
- Aalborg AQ-series
- Aalborg AQ12
- Steam to steam generator
- Double evaporation boiler
- Composite boiler Aalborg OC type
- Water Tube Boilers
- D type water tube boiler
- Natural circulation within boiler
- Major boiler components
- Types of tubes and functions
- Aalborg water tube boilers
- Types of Water Tube Boilers
- Babcock Wilcox
- Foster Wheeler
- Foster Wheeler Boilers
- V2M-8 Main Boiler - Combustion Engineering
- Once Through Boilers
- Once-through Boiler Types
- Waste heat recovery
- Design considerations for waste heat recovery
- Types of waste heat recovery boilers
- Exhaust Gas Economizer
- LaMont Exhaust Gas Boilers
- Operation of boiler and economizer underway
- Starting operation of the EGR Boiler system
- Precautions for using exhaust gas economizer
- Fire in Exhaust Gas Boilers
- Soot Deposits and Soot Fire
- Limitation of boiler exhaust gas temperatures
- Comparing Waste Heat Recovery Potential
- Air Heaters and Economizers for WHR
- Boiler Mountings
- Mountings and their functions
- Fittings on toiler shell
- Main and auxiliary steam stop valves
- Feed check valve
- Class rules for mountings and fittings
- Automatic feed regulation
- Feed Control Valve
- Safety Valves and easing gear
- Low Lift Safety Valve
- Improved High Lift
- Full lift and full Bore type:
- Classification rules for Safety valves
- Procedure for setting safety valves
- Maintenance of safety Valve
- Drum Mounted Water Level Indicators
- Gauge Glass Operations
- Classification rules- Water level Gauges
- Remote Level Water Level Indicators
- Modern Electronics for Remote WL Indicators
- Steam Pipes
- Reducing valve
- Steam Traps and handling of exhaust steam
- Steam trap testing and maintenance
- 6. Combustion system and safeties
- Quality of Combustion
- Smoke measurement and stack losses
- Viscosity end Fuel burning
- Fuel systems and associated components
- Boiler Fuel Oil System
- Fuel system and properties
- Shell and Tube Heat Exchanger
- Rotary Pumps
- Filters and Strainers
- Auto-kleen strainers
- Relief valves
- Quick closing valves
- Combustion process and equipment
- Process of Liquid Fuel Burning in Open Furnace
- Refrutory Materials in Boilers
- Fuel burning and equipment
- Air Register
- Burners
- Steam atomizer
- Maintenance of burner systems
- Automation and Burner Management
- Boiler Combustion Control Systems
- Control of Air/Fuel Ratio
- Burner Management System
- Safety System and Sequential Ignition
- Auxiliary Boiler Safety System
- Advanced Burner Management System (BMS)
- Marine boiler control system using PLC
- PLC based BMS and Safety System
- Coil type Package Boiler
- Boiler Water Treatment
- Impurities in Feed Water
- Boiler Corrosion and Scale formation
- Corrosion in Boilers
- Internal waterside corrosion
- Combination of Electrolytic and Mechanical or Chemical attack
- External Lubrication Oil System
- Scale formation in boilers
- Boiler Water Tests on Board
- Treatment of boiler feedwater
- Internal Treatment
- Alkalinity and Oxygen Control
- Low Alkalinity Treatment
- Blowing Down of Boiler
- Operation care and maintenance of boiler
- High Pressure Boiler Operation
- Important Operating Precautions
- Emergency and Abnormal Running Condition
- Action in the Event of Shortage of Water
- Maintenance and troubleshooting-boiler plant
- Regular Maintenance Prccedures
- Boiler Survey
- Casualty Control in boiler plants
- Troubleshooting Procedures
- Soot blowers
- Sootblowers for high pressure boilers
- Diamond Retractable Soot Blower
- Tube repairs and renevvals
- Temporary Take You Home Repair
- Sunrod Membrane Wall Tube Repairs
- Re-tubing and Tube Replacement for Boilers
- Feedwater systems
- Open Feed Water System
- Closed Feed Water System
- Feed System Components
- Condenser
- Deaerator/DC Heater
- Air Ejector and Condenser
- Heater
- Extraction Pump end Feed Pump
- Boiler Feed Pump
- Water Lubricated Feedpump
- Engine Operations and Safety
- Coffin Turbo Pump
- Evaporators
- Eva rator types
- Construction, operation and characteristics of FW generator and Vaccum Evaporators
- Condensate Systems1
- Condensers 1
- Condensers 2
- Constructional Details
- W:ation and Working Principles
- Contraction and Expansion Allowances
- Condenser Cooling Water Circulation
- Leakage Detection and Tube plugging
- Condenser Tul Failures
- Performance check of a Condenser
- Condenser Materials
- Effect of Change of Temperature
- Change of Main Engine Power
- Condenser Surface
- Condensate Return system
- Steam Engines and Turbines
- Steam Engines History of Steam Power
- Improvement of Early Steam Engines
- The Steam Engine in Transportation
- History of Multiple Expansion Marine Reciprocating Engines
- Description of the Power Plant
- Power and Efficiency of the Reciprocating Steam Engines
- Rise and Fall of Steam Turbines
- Steam Turbines for Sea Transportation
- The Demise of Steam Era at Sea
- Principles of Steam Turbines
- Use Of Different Blade Stages
- Practical Steam Cycles and Efficiencies
- Turbine Configurations and Compounding
- Types of Steam Turbines
- Various Turbine Designs and Arrangements
- Multistage Arrangement of a Steam Turbine
- Turbine Constructional Features
- Nuclear Fueled Steam Propulsion
- Main Steam Turbines
- Stal-Laval cross-compound geared turbine
- Future Of Steam Turbines
- Use of steam turbine in a combined cycle
- COGES system
- Endnote on Marine Steam Turbine
- Turbine Materials
- Materials used in Various Components
- Rotors
- Casings
- Blading
- Gears
- Auxiliary Turbines
- Auxiliary Steam Turbine Generators
- Constructional Details
- Turbine Oil and the Lube Oil System
- Gland Sealing system
- Safety Protection System
- Speed Goveming System
- Turbo Generator Operation
- Cargo Pump Turbines
- Lubrication Systems
- Turbine Lube Oil: Principle and Propertie
- Selection and Properties of Lube Oil
- Categories and Specifications
- Turbine Lubrication Principles
- Turbine Gravity and Pressure Lubricating Oil System
- Extemal Lubrication Oil System
- Internal Lubricating Oil System
- The Direct Shaft Driven Oil Pump
- Gravity Tanks
- Emergency Lube Oil Pressure Trip
- Turbo-Generator Lubricating Oil System
- Monitoring the Lube Oil System
- Thrust Bearings
- Construction and Operation of Thrus
- Journal Bearings
- Flexible Coupling
- Drive Systems
- Gears and Clutches
- use of Gears
- Gear Teeth Design
- Lubrication
- Parallel gear Applications
- Epicyclic earing
- Application of Epicyclic Gearing
- Star Gear
- Planetary Gear
- Solar Gear
- Advantages of Using Multiple Planets
- Epicyclic Gear Arrangements
- Clutches and Reversing Gears
- Reduction Gears
- Double Reduction Parallel Gears
- A Triple Reduction with Epicyclic Gearing
- Auxiliary Diesels
- Diesel Engine Principles
- Fundamentals of DE
- Terminology
- Cycle, Timing Diagram
- Power and Efficiency
- Types
- Conclusion
- Auxiliary Diesel Engine Features
- Constructional features
- Advantages and Types
- Conclusion2
- Auxiliary Engine Systems
- Lubricating Oil System
- Aux Diesel Lube System
- Lubrication of 4-stroke diesel
- Fuel Oil System
- Jacket Cooling Water System
- Starting Air System
- Exhaust Gas Turbocharging
- Operation of Auxiliary Engines
- Engine Oprations and Safety
- Operating Troubles
- Conclusion
- Maintenance of Auxiliary Diesels
- Precautions for Maintenance
- Filters
- Crankcase Inspection
- Crankshaft Deflection
- Cylinder Head assembly
- Inlet and Exhaust Valves
- Air Start Valves
- Fuel Injector
- Indicator and Safety valve
- Rocker Arm Assembly
- Piston Assembly
- Piston
- Connecting Rod
- Cylinder Liner
- Fuel Pumps
- Overhaul Procedure
- Fuel Pump Timing
- Case study
- Some Major Repairs
- Conclusion
- Downloads
- References
- External link
- Safety of Turbine Operations
- Turbine Systems
- Turbine Steam Inlet System
- Turbine Gland Sealing System
- Turbine Drain System
- Turbine Running
- Warming Through a Turbine Plant
- Emergency Running of Damaged Turbines
- Steam Turbine Losses
- Control of Power and Speed of Propulsion
- Throttle Valve Control and Nozzle Control
- Maneuvering Vatves
- Emergency Controls and Turbine Operations
- A Modern Maneuvering and Safety
- Speed Governing System
- Speed Governor- Main Turbine
- Casualty Control- turbine plant
- Maintenance of Steam Turbine
- At Sea Checks
- In Port Maintenance
General considerations for design of boilers
General considerations for design of boilers
Specific Learning Objectives:
After going through the topic student should be able to,
- Know important definitions and terms used in steam engineering
- Understand the concept of various types of heat transfer
- Understand the concept of Specific heat capacity, Latent heat capacity and Sensible heat
- Understand the use of Property diagram and Steam Table
- Understand the concept of Enthalpy and Entropy
- Understand the concept of a reversible process as applicable to the steam engine thermodynamic cycle
Introduction
Steam is a form of water and thus available in plentiful in the world. On board a ship, surrounded by the sea, it is possible to evaporate the salt water and produce distilled water which has very low solid content. It is this water which is fed into the ship's boilers to produce steam. The heat energy comes from burning the oil in the boiler furnace. The enclosed boiler is where the steam is collected at high pressures on top of the water inside the drum. The steam, thus produced , goes for further transformation by absorbing more heat from flue gas outside the drum to become superheated vapor which is fed to the turbines to produce work. As water is heated, boiled to steam vapors and further superheated, the steam carries progressively more heat energy as its pressures and temperatures are raised in the boiler system.
So, the real job of the water or the steam is just carrying the heat from combustion of fuel in the gas side of the boiler, and deliver that to the heat engines. Whatever heat is not able to be absorbed by the turbine engine (heat engine) is rejected with the exhausted steam to the Condenser; the exhaust steam is condensed and recycled back as feedwater to the boiler. During the passage, water or steam acts only as a carrier of heat and does not gets spent or consumed; except for some small leakage through pipelines and atmosphere due to evaporation and radiation. If you ignore those losses, the entire steam (in the form of recycled water) goes back to the boiler. And, the steam and water goes round and round the plant in a cyclic process. This is called a steam cycle.
The steam is such a fluid, which when pressurized, carries increasingly more heat and it's temperature can also be raised to make it into a superheated steam outside the boiler drum, so that it can carry even more heat and then deliver that to the turbines in the form of a high temperature and pressure steam which gets expanded through the turbine stages - thereby consuming the heat brought in by the steam and convert the pressure drops and changes in velocity into work by rotating the turbine wheels, which ultimately moves the ship's propeller.
Definition and Terms
There are a number of technical terms used in connection with steam generation. Some of these commonly used terms you should know are as follows:
- Degree is defined as a measure of heat intensity.
- Temperature is defined as a measure in degrees of sensible heat. The term sensible heat refers to heat that can be measured with a thermometer.
- Heat is a form of energy measured in British thermal units (BTU). One Btu is the amount of heat required to raise 1 pound of water 1 degree Fahrenheit
- Steam means water in a vapor state. Dry saturated steam is steam at the saturation temperature corresponding to pressure, and it contains no water in suspension.
- Wet saturated steam is steam at the saturation temperature corresponding to pressure, and it contains water particles in suspension.
- The quality of steam is expressed in terms of percent. For instance, if a quantity of wet steam consists of 90 percent steam and 10 percent moisture, the quality of the mixture is 90 percent.
- Superheated steam is steam at a temperature higher than the saturation temperature corresponding to pressure. For example, a boiler may operate at 415 psig (pounds per square inch gauge). The corresponding saturation temperature for this pressure is 483°F, and this will be the temperature of the water in the boiler and the steam in the drum. This steam can be passed through a super-heater where the pressure remains about the same, but the temperature will be increased to some higher figure, called the degrees of superheat.
Fire Tube Boiler
As it indicated from the name, the firetube boiler consists of numbers of tubes through which hot gasses are passed. These hot gas tubes are immersed into water, in a closed vessel. Actually, in fire tube boiler one closed vessel or shell contains water, through which hot tubes are passed. These fire tubes or hot gas tubes heated up the water and convert the water into steam and the steam remains in same vessel. As the water and steam both are in same vessel a firetube cannot produce steam at very high pressure.
Water Tube Boiler
Watertube boiler is reverse of the fire tube boiler. In water tube boiler the water is heated inside tubes and hot gasses surround these tubes.
A water tube boiler is a type of boiler in which water circulates in tubes heated externally by the fire. Fuel is burned inside the furnace, creating hot gas which heats water in the steam-generating tubes. In smaller boilers, additional generating tubes are separate in the furnace, while larger utility boilers rely on the water-filled tubes that make up the walls of the furnace to generate syeam.
The heated water then rises into the steam drum. Here, saturated steam is drawn off the top of the drum. In some services, the steam will reenter the furnace through a superheater to become superheated. Superheated steam is defined as steam that is heated above the boiling point at a given pressure. Superheated steam is a dry gas and therefore used to drive turbines, since water droplets can severely damage turbine blades.
Cool water at the bottom of the steam drum returns to the feedwater drum via large-bore 'downcomer tubes', where it pre-heats the feedwater supply. (In large utility boilers, the feedwater is supplied to the steam drum and the downcomers supply water to the bottom of the waterwalls).
The water tube boiler is used to generate steam having high pressure and temperature. These small internal parts produce high volume steam for high-capacity applications.
Water tube boilers are the most widely used boilers. These type has replaced many boilers, including the fire tube type, mainly because of the following reasons:
- The weight of the water tube boiler is much less than any type of boiler of equivalent size.
- Steam raising and steam generation process is much faster
- The design is custom made and flexible to include any kind of modifications
- It has very high efficiency than the rest of the boilers
- The design facilitates good natural circulation of the feed water
Uses of steam on ships
- For propulsion uses to drive the steam ships.
- For electric power generation on steam and few motor ships.
- Used to drive the cargo pumps in tankers ships to transfer the oil.
- Winch and windlass are also driven by steam in some ships like tankers.
- For operation of cargo oil pump on most oil tankers.
- On steam ships, this steam is used for taking or making vacuum inside the condensers.
- The stripper pumps are driven by the steam ships. For cargo heating on both steam and motor tankers.
- For warming up the engine in cold areas and prior to starting.
- For operation of ships whistle on all steam ships and few oil tankers.
- Fuel oil like heavy oil and the lubrication oil in some cases are heated with the help of steam.
- Sea chest is blown through with help of steam.
- One major use of steam on board ship is to soot blow on most ships.
- Derrick on some ships is driven with the help of steam only.
- Heating of the accommodation in colder seasons.
