Vocabulary

use, v использовать

propel, v приводить в движение

steamproducingplant паропроизводящая установка

steamconsumingplant паропотребляющая установка

burner, n форсунка

vary, v изменяться

surface, n поверхность

movingblades движущиеся рабочие лопатки

turbo-driven ship турбоход

e x e r c I s e s

1. Choose the proper verb form.

1. A steam power plant /convert; converts; is converted/ the energy of fuel into mechanical energy.

2. The heat generated in the furnace /transmit; is transmitted; transmits/ to the boiler.

3. Temperature and pressure of the steam /drops; drop; is drop/ in passing through the turbine.

4. The steam from the turbine /pass; passes; passing/ to the condenser.

5. The mechanical energy /is expressed; express; are expressed/ in horsepower.

2. Answer the questions.

1. What is a steam power plant used for?

2. What units does s steam power plant consist of?

3. How is the steam in the steam power plant formed?

4. Where is the energy of steam converted into kinetic energy?

5. What energy is the kinetic energy converted into at the turbine moving blades?

6. Where is the steam from the turbine changed into water?

7. What ships is the steam power plant installed in?

UNIT 2

TEXT A

CLASSIFICATION OF MARINE BOILERS

Marine boilers are classified in different ways:

1. By the purpose they are designed for marine boilers are classified as main and auxiliary, or donkey boilers.

The main steam boilers generate steam for the main engines, driving the propeller and for auxiliaries. The auxiliary boilers generate steam only for the auxiliaries, heating of oil and fuel tanks and other ship’s needs.

2. By their structure boilers are classified as the fire-tube boilers and the water-tube boilers.

The fire-tube boiler, or a Scotch boiler, consists of a cylindrical steel shell, whichcontains a furnace at the bottom. Two or more furnaces may be fitted, depending on the size of the boiler. The furnace is connected to a combustion chamber, situated in the middle part of the boiler. The furnace, the combustion chamber and the tubes are all surrounded by water.

Water-tube boilers have replaced fire-tube boilers. In the water-tube boiler feed water passes through the tubes surrounded by hot gases. It is used for high pressure, high temperature, and high capacity steam applications, e.g. providing steam for the main propulsion turbine or cargo pump turbines.

3. By the principle of water and steam water mixture motion the boilers are classified as natural and forced circulation boilers.

The process of natural circulation occurs due to density difference of water and steam water mixture.

If the working fluid is forced through the boiler by an external pump, the circulation is called the forced one.

4.By the way they are supplied with air boilers are classified as natural draft, forced draft and supercharged boilers.

In natural draft boilers fuel is burnt under the pressure equal to the atmospheric pressure;forced draft is produced by placing a fan in the uptake, and exhausting through the furnaces; in supercharged boilers the pressure is much higher than the atmospheric pressure.

NOTES:

depending on – взависимостиот

e.g. = for example – например