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Variant 5 (done)
Task 1. Read the following text to answer these questions.

a)    What arrangements does the main steam system include?
The Main Steam System includes only the piping, which carries superheated steam fr om the boilers to the propulsion turbines, the turbo-generators, and the soot blowers.
b)    What valves are fitted on the superheated steam piping?
The superheated steam passes through the main steam strainer, a stop valve, and a throttle valve before entering the high pressure turbine
c)    Where does steam go fr om the low pressure turbine?
It exhausts to the condenser.
d)    What systems and machinery use auxiliary steam?
Air compressors, whistles and sirens, fuel oil tank heating coils, air ejectors, forced draft blowers and pumps are typical of the systems and machinery use auxiliary steam on most steam-driven ships.
e)    What does the term "desuperheated" mean?
Desuperheating is the process by which superheated steam is restored to its saturated state, or the superheat temperature is reduced.
f)    What is the gland sealing system used for?
Gland sealing steam is supplied to the shaft packing glands of propulsion turbines and turbogenerator turbines to seal the shaft glands against two kinds of leakage: (1) air leakage into the turbine casings, and (2) steam leakage out of the turbine casings.
g)    What are the two kinds of leakage occurring in the turbine casing?
Two kinds of leakage are: (1) air leakage into the turbine casings, and (2) steam leakage out of the turbine casings.

h)    Wh ere do the condensate and feed systems begin and wh ere do they end?
The condensate and feed systems begin at the condenser and end at the economizer of the boiler.
i)    What do we call water collected at the bottom of the condenser?
It is called a condensate.
j)    Why is the condenser called a heat exchanger?
The condenser called a heat exchanger because it comes in contact with tubes through which cool seawater is flowing.
k)    By what means are non-condensable gases removed from the condenser?
The function of an air ejector is to remove air and other non-condensable gases from the condenser. An air ejector is a type of jet pump, containing no moving parts. The flow through the air ejector is maintained by a jet of high velocity steam passing through a nozzle.
l)    Can you explain the meaning of the term "standby condition"?
standby condition is a condition when one pump is in use and the other is kept in reserve.
m)    In what units is vacuum expressed in the text?
It is expressed in inches of mercury.

Steam Systems
On many ships, the Main Steam System includes only the piping, which carries superheated steam from the boilers to the propulsion turbines, the turbo-generators, and the soot blowers. On some modern ships, the main steam system is more complex because more units use superheated steam.
For ahead operation, the superheated steam passes through the main steam strainer, a stop valve, and a throttle valve before entering the high pressure turbine. From the high pressure turbine, the steam passes through a cross-over pipe to the low pressure turbine, then it exhausts to the condenser.
For astern operation, the superheated steam passes through the steam strainer and through a stop valve, then it goes to the steam chest of the astern turbine, which is located at one end of the pressure turbine.
Auxiliary Steam Systems supply saturated steam at the pressures and temperatures required for the operation of many systems and units of machinery. Air compressors, whistles and sirens, fuel oil tank heating coils, air ejectors, forced draft blowers and pumps are typical of the systems and machinery that use auxiliary steam on most steam-driven ships.
On ships having single-furnace boilers, all steam goes through the superheater and the steam, which is required for auxiliary steam systems, is then desuperheated.
The Auxiliary Exhaust System receives exhaust steam from pumps, namely feed pumps, and other auxiliaries, which do not exhaust directly to a condenser. Auxiliary exhaust steam is used in various units, deaerating feed tanks, distilling plants, and turbine gland sealing systems. The pressure in the auxiliary system is maintained at 15 psig.
Gland sealing steam is supplied to the shaft packing glands of propulsion turbines and turbogenerator turbines to seal the shaft glands against two kinds of leakage: (1) air leakage into the turbine casings, and (2) steam leakage out of the turbine casings. Pressures in the gland seal system are low, ranging from about 3/4 psig to 2 psig, depending upon the conditions of operation.

Condensate and Feed Systems
The condensate and feed systems include all the piping that carries water from the condenser to the boilers and from feed tanks to the boilers. The condensate system includes the main and auxiliary condensers, pumps and piping. The boiler feed system includes the main feed pump, and the piping required to carry water from the deaerating feed tank to the boilers. Together, the condensate and feed systems begin at the condenser and end at the economizer of the boiler.
The main condenser is a heat exchanger in which exhaust steam is condensed as it comes in contact with tubes through which cool seawater is flowing. The steam enters at the top of the condenser and the water (now called condensate) collects at the bottom of the condenser, below the tubes. The main condenser is maintained under a vacuum of approximately 27 to 29.5 inches of mercury.
The condensate pump pumps the condensate from the condenser to the deaerating feed tank. As a rule, two condensate pumps are used for each condenser; under normal conditions, one pump is in use and the other is kept in standby condition.
The function of an air ejector is to remove air and other non-condensable gases from the condenser. An air ejector is a type of jet pump, containing no moving parts. The flow through the air ejector is maintained by a jet of high velocity steam passing through a nozzle.


Task 2. Match each item in column A with appropriate item in column B.
Example: 2 - j.
A    B
1.        Steam    n)        boilers
2.        Heating    o)        operation
3.        Turbo    p)        valve
4.        Auxiliary    q)        generators
5.        Air    r)        exchanger
6.        Superheated    s)        steam system
7.        Forced    t)        ejectors
8.        Ahead    u)        leakage
9.        Saturated    v)        steam
10.        Throttle    w)        coils
11.        Single-furnace    x)        draft
12.        Air    y)        condition
13.        Heat    z)        pump
14.        Stand by    aa)        steam
15.        Jet    bb)        chest

15 z); 14 y); 12 u); 5 t); 11 n); 10 p); 9 v); 8 o); 7 x); 6 aa); 4 s); 3 q); 2 w); 1 bb).


Task 3. Try to explain

    the way of the superheated steam in different operation modes;
For ahead operation, the superheated steam passes through the main steam strainer, a stop valve, and a throttle valve before entering the high pressure turbine. From the high pressure turbine, the steam passes through a cross-over pipe to the low pressure turbine, then it exhausts to the condenser.
For astern operation, the superheated steam passes through the steam strainer and through a stop valve, then it goes to the steam chest of the astern turbine, which is located at one end of the pressure turbine.

    the function of the piping, heat exchanger, condensate pump, air ejector.
The piping carries superheated steam from the boilers to the propulsion turbines, a heat exchanger is a unit in which exhaust steam is condensed as it comes in contact with tubes through which cool seawater is flowing, the condensate pump pumps the condensate from the condenser to the deaerating feed tank, the function of an air ejector is to remove air and other non-condensable gases from the condenser.

Task 4. Describe the distinctions between the superheated and saturated steam.
Superheated steam is steam that is at a temperature higher than the saturation temperature for the steam pressure. For example, steam at a pressure of 3 bar g has a saturation temperature of 143.762°C. If further heat were to be added to this steam and the pressure remained at 3 bar g,it would become superheated. This extra heat results in steam which:
• Is higher than saturation temperature.
• Contains more energy than saturated steam.
• Has a greater specific volume than saturated steam


Task 5. What are the names of these objects?
System and machinery that use:
    auxiliary steam;
Air compressors, whistles and sirens, fuel oil tank heating coils, air ejectors, forced draft blowers and pumps are typical of the systems and machinery use auxiliary steam on most steam-driven ships.
    auxiliary exhaust steam.
Auxiliary exhaust steam is used in various units, deaerating feed tanks, distilling plants, and turbine gland sealing systems.

Task 6. Make a list of components of Condensate and Feed Systems.
The condensate system includes the main and auxiliary condensers, pumps and piping.
The feed system includes the main feed pump, and the piping required to carry water from the deaerating feed tank to the boilers.


Task 7. Put the statements in the correct sequence.

16.    The system the piping soot main includes only the and turbo-generators steam the blowers.
The main steam system includes only the turbo-generators, and the soot blowers.
17.    For operation many of supply auxiliary and saturated systems units of steam machinery systems steam the.
Auxiliary steam systems supply saturated steam for the operation of many systems and units of machinery.
18.    Pressure maintained system at the auxiliary in the 15 is psig.
The pressure in the auxiliary system is maintained at 15 psig.
19.    Includes the condensers piping the system pumps and main auxiliary condensate and.
The condensate system includes the main and auxiliary condensers, pumps and piping.
20.    System the piping feed the includes pump and feed the boiler main.
The boiler feed system includes the main feed pump, and the piping.
21.    Are condenser for pumps a condensate used rule each as two.
As a rule, two condensate pumps are used for each condenser.

Task 8. Complete the sentences with the correct form of the verb in the box

be    desuperheat    keep    condense    be    locate    maintain    pass

On some modern ships, the main steam system ____is____ more complex. From the high pressure turbine the steam ____passes__________ through a cross-over pipe to the low pressure turbine. The astern turbine ____is located___________ at the end of the pressure turbine. The steam __ desuperheats__________. Exhaust steam ___condenses___________ in a heat exchanger. The main condenser _____is maintained_________ under a vacuum of approximately 27 to 29.9 inches of mercury. One pump _____is____ in use and the other ___is kept_____ in standby condition.

Task 9. Write a brief description of Main and Auxiliary Turbines. It must consist of some paragraphs. Your description should answer these questions.

    What are they designed to?
    What do they consist of?
    What are the similarities and distinctions between the two principal types of turbines?

    Steam turbines are used for ship propulsion and for driving many of the auxiliary machinery units associated with the propulsion plant, such as lubricating pumps, condensate pumps, feed pumps, circulating pumps, fuel oil pumps, forced draft blowers, and electric generators.
The two principal types of steam turbine ship propulsion plants in use today are the geared-turbine drive and the turbo-electric drive.
In the geared-turbine drive, a reduction gear unit is used as the means for transforming high turbine rpm to a much lower propeller shaft rpm.
In the electric drive, the necessary speed reduction is done electrically. That is the turbine drives a generator at high rpm; and the generator supplies power to drive an electric propulsion motor, which operates in a low rpm range.
In the geared-turbine drive, the propulsion shaft, which extends from the low speed shaft of the reduction gear to the propeller, is supported and held in alignment by the spring bearings and the stern tube bearings.
The axial thrust, acting on the propulsion shaft as a result of the pushing effect of the propeller, is absorbed in the main thrust bearing. In most ships, the main thrust bearing is located at the forward end of the main shaft, within the reduction gear casing. In some very large ships, however, the main shaft thrust bearing is located farther aft in a machinery space or a shaft alley.
Unlike gear-turbine propulsion plants, which have two ahead turbines and an astern element for propulsion shaft, the turbo-electric drive installations have a single turbine unit for each installed shaft. The propulsion unit includes a turbine, main generator, propulsion motor, a direct current generator for supplying excitation current to the generator and propulsion motor, and a propulsion control board.
The basic distinction between turbines concerns the manner in which the steam causes the turbine rotor to move. When the rotor is moved by a push or impulse from a high velocity jet of steam that strikes the blades mounted on the wheel, the turbine is called an impulse turbine. When the rotor is moved by the force of reaction, the turbine is called a reaction turbine.