4) High Economy: Ensuring performance at full load, while a slight performance decrease at load, la

1) Use safety is the most important requirement, so that not only the damage done to the ship boiler will not run, even to the vessel caused the crash, so the boiler is only used for boiler type structure durable, strong and proven long term.
2) Compact, lightweight, easy layout to increase the tonnage of the ship, extended range operation of ships. Therefore boilers heat load type large capacity oven, large evaporation capacity, rapid flue gas flow rate, the number elected at the pot, the pot and the pipe diameter gourd baby to reduce thickness and weight.
4) High Economy: Ensuring performance at full load, while a slight performance decrease at load, large oil-fired boilers to achieve 91-93% efficiency. Boilers of civil ships often have higher performance than general requirements in terms of weight and size is not very high.
5) High Mobility: the stove to take a little time can quickly reduce the load rapidly increased to adapt to changes in the working mode of the engine. When adjusted positions vessels, pressure and steam temperatures remain relatively stable, although the boiler feed water temperature that fluctuates. Boilers need to have large reserves of energy, combustion poulaillon chamber less inertia. When necessary, the ability to load 25 to 45%. When the ship tilted horizontal shaking 0 30, 12 0 inclined pitching ensure the heat absorption surface without protruding out of the water. When the fuel supply in many types of port, still work in relatively poulaillon good condition.
Note that the requirement of dissimilar types of vessels: passenger poulaillon ships, cargo ships running poulaillon routing a steady supply of fuel, conditional check in port repair, poulaillon adjustment time ship locations (Mano ) less, most of the time working at full capacity will be needed to ensure high performance when running normally ship (full speed). Tugs, fishing vessels, work boats ... sometimes gently tug the need to maneuver better requirements and ensure high performance even when flicking. Warships require oven time group took a short breath, high mobility.
Requirements for marine boilers different from the boiler on: Dimension weight, compact structure poulaillon to simpler, better fuel. But generally marine boilers shutdown conditions should always wash the pot regularly and repair (usually longer than one year on the new shutdown repaired).
The above requirements can not fully agree. For example: The amount of water will shorten the pot at the stove to time, reduce weight boiler, but the water level and steam pressure cooker may be less stable.
As the largest amount of steam generated per unit of time under conditions of steam boilers provide long-term stability. General steam production is the sum of the output DN bit D hs drying, drying yields slightly decreased P gs, saturated output D x.
Note that D x is the amount of saturated steam supplied to the machine parts and systems (rather than the amount of saturated steam generated to create elected cradle) when necessary, the boiler can overload the largest output D max within a specified number of hours.
Is the ratio of useful heat boiler on heat emitted by the fuel.
As metal surfaces (walls of the tube, boiling water pipe, water pipe heating savings, steam tube dryers, air heater poulaillon tubes or pipes of fire hoses, fire box, the combustion chamber) heat absorption, heat exchanger (such as gas oven, steam dryer) heat transfer to the acceptor poulaillon (water, steam, air). As for the drying of the surface poulaillon reduces heat absorption poulaillon of water vapor transmission ..
As soot builds irritated, reduce evaporation rate.
In order to ensure complete combustion quality, in addition to providing full requirements of oxygen also need to make sure the temperature in the combustion chamber space edged higher combustion temperature of the fuel, the flue gas temperature in the combustion chamber is sufficient high radiation heat transfer is strong, the flame of fuel should not be exposed to the surface is not attractive surface temperature (if not then the fuel will not burn completely to the black mug on the surface was ).
So the value of V bd to select poulaillon a moderate, depending on the type of combustion chamber, fuel type, fuel quantity, air temperature oven. The minimum value of the combustion chamber volume determined by production volume combustion chamber poulaillon heat load.
For oil burners, qv values to ensure that the combustion chamber refractories not burned down. Where the oil fired boiler poulaillon walls with large area, can qv values greater than 0.6 0,7.10 qv = 6 kcal / m 2 h.
Note that qv characteristic for the long term fuel flow to the combustion poulaillon chamber. If you need to consider flue gas temperature in the combustion chamber, the fuel outside of the heat, the heat must also consider the physics of gas and hot air heat brought into the combustion chamber.
- Fire tube boilers: W = 3 8
As fertility by adding a little heat in the water, the metal walls of the combustion chamber and the sudden need to increase the steam. Call D, D 0 is the normal amount of steam production and the need to dramatically increase the amount of steam generation.
Boilers provide steam for the plant. Of the exhaust steam condenses poulaillon back into water supply for condenser boiler, condensate is not entirely pure. Salt water outside the vessel may elect to stop leakage into condensate mixed. Lubrication of the cylinder steam engine poulaillon though