EXPERIMENT 1 LAYOUT AND PIPING OF THE STEAM POWER PLANT SYSTEM

1.0 LEARNING OUTCOMES

1.1 To learn about the equipment used in steam producing.

1.2 To learn the application of the equipment used in steam producing.

1.3 To study the layout and piping of the steam power plant system.

2.0 APPARATUS/EQUIPMENT

COMPONENT

TURBINE COOLING TOWER

CONDENSER SUPERHEATED

FUEL STORAGE WATER COLLECTED

TEMPERATURE DRYNESS FRACTION

OVERVIEW OF STEAM POWER PLANT

MINI STEAM POWER PLANT PLANT LAB PUO

3.0 SAFETY AND HEALTH 3.1 Make sure the student follow the laboratory or

workshop safety regulations.

3.2 Experiment must be conduct by lecturers or

experience lab assistance.

3.3 Always know the hazards associated with the material

that are being utilized in the lab.

3.4 Always wear appropriate protective clothing.

3.5 Never perform unauthorized work,preparations or experiments.

3.6 Be familiar with the location of emergency equipment

such as fire alarm,fire extinguisher,emergency eye

wash and safety shower

3.7 Know the appropriate emergency response procedures.

4.0 THEORY

A thermal power station is a power plant in which the prime mover is steam driven.

Water is heated, turns into steam and spins asteam turbine which drives an electrical

generator. After it passes through the turbine, the steam is condensed in

a condenser and recycled to where it was heated; this is known as a Rankine cycle.

The greatest variation in the design of thermal power stations is due to the

different fossil fuel resources generally used to heat the water. Some prefer to use

the term energy center because such facilities convert forms of heat energy into

electrical energy.Certain thermal power plants also are designed to produce heat

energy for industrial purposes of district heating, or desalination of water, in addition

to generating electrical power. Globally, fossil fueled thermal power plants produce a

large part of man-made CO2 emissions to the atmosphere, and efforts to reduce

these are varied and widespread.

More about thermal power system(types of thermal power system)

Almost all coal, nuclear, geothermal, solar thermal electric, and waste incineration

plants, as well as many natural gas power plants are thermal. Natural gas is

frequently combusted in gas turbines as well as boilers. The waste heat from a gas

turbine can be used to raise steam, in a combined cycle plant that improves overall

efficiency. Power plants burning coal, fuel oil, or natural gas are often called fossil-

fuel power plants. Some biomass-fueled thermal power plants have appeared also.

Non-nuclear thermal power plants, particularly fossil-fueled plants, which do not

use co-generation are sometimes referred to as conventional power plants.

Commercial electric utility power stations are usually constructed on a large scale

and designed for continuous operation. Electric power plants typically use three-

phase electrical generators to produce alternating current (AC) electric power at

a frequency of 50 Hz or 60 Hz. Large companies or institutions may have their own

power plants to supply heating or electricity to their facilities, especially if steam is

created anyway for other purposes. Steam-driven power plants have been used in

various large ships, but are now usually used in large naval ships. Shipboard power

plants usually directly couple the turbine to the ship's propellers through gearboxes.

Power plants in such ships also provide steam to smaller turbines driving electric

generators to supply electricity. Shipboard steam power plants can be either fossil

fuel or nuclear. Nuclear marine propulsion is, with few exceptions, used only in naval

vessels. There have been perhaps about a dozen turbo-electric ships in which a

steam-driven turbine drives an electric generator which powers an electric

motor for propulsion.

Combined heat and power plants (CH&P plants), often called co-generation plants,

produce both electric power and heat for process heat or space heating. Steam and

hot water lose energy when piped over substantial distance, so carrying heat energy

by steam or hot water is often only worthwhile within a local area, such as a ship,

industrial plant, or district heating of nearby buildings.

5.0 DISCUSSION

5.1 State all the components used in steam power

plant and give the explanation of theirs uses.

1. Boiler. A boiler is a closed vessel in which water or other fluid is heated.

The fluid does not necessarily boil. The heated or vaporized fluid exits

the boiler for use in various processes or heating applications.

2. Steam turbine. A steam turbine is a device that extracts thermal

energy from pressurized steam and uses it to do mechanical work on a

rotating output shaft. Because the turbine generates rotary motion, it is

particularly suited to be used to drive an electrical generator. The steam

turbine is a form of heat engine that derives much of its improvement

in thermodynamic efficiency from the use of multiple stages in the

expansion of the steam, which results in a closer approach to the ideal

reversible expansion process. 

3. Cooling tower. A cooling tower is a heat rejection device which

extracts waste heat to the atmosphere through the cooling of a water

stream to a lower temperature. Cooling towers may either use

the evaporation of water to remove process heat and cool the working

fluid to near the wet-bulb air temperature or, in the case of closed circuit

dry cooling towers, rely solely on air to cool the working fluid to near

the dry-bulb air temperature.

4.Water pump. A water pump is a specific type of pump used to

pump feedwater into a steam boiler. The water may be freshly supplied

or returning condensate produced as a result of the condensation of the

steam produced by the boiler. These pumps are normally high pressure

units that take suction from a condensate return system and can be of

the centrifugal pump type or positive displacement type.

5. Surface condenser. A surface condenser is a commonly used term for a

water-cooled shell and tube heat exchanger installed on the

exhaust steam from asteam turbine in thermal power stations.[1][2]

[3] These condensers are heat exchangers which convert steam from its

gaseous to its liquid state at a pressure below atmospheric pressure.

5.2 Briefly explain the work cycle of the steam power plant

Rankine cycle. Rankine cycle is a model that is used to predict the

performance of steam turbine systems. The Rankine cycle is an

idealizedthermodynamic cycle of a heat engine that converts heat into

mechanical work. The heat is supplied externally to a closed loop, which

usually uses water as the working fluid.

There are four processes in rankine cycle

Process 1-2: The working fluid is pumped from low to

high pressure. As the fluid is a liquid at this stage, the pump requires little input

energy.

Process 2-3: The high pressure liquid enters a boiler where it is heated at

constant pressure by an external heat source to become a dry saturated vapour.

The input energy required can be easily calculated using mollier diagram or h-s

chart or enthalpy-entropy chart also known as steam tables.

Process 3-4: The dry saturated vapour expands through a turbine, generating

power. This decreases the temperature and pressure of the vapour, and some

condensation may occur. The output in this process can be easily calculated

using the Enthalpy-entropy chart or the steam tables.

Process 4-1: The wet vapour then enters a condenser where it is condensed at

a constant pressure to become a saturated liquid.

5.3 What are advantages of using steam as a medium In generating power.

Steam offers the following advantages:

1) Steam can be distributed throughout a heating system with little change in temperature

2) Steam flows through the system unaided by external energy sources such as pumps.Because of its low density, steam can be used in tall buildings where water systems create excessive pressure.

3) Steam is pressure-temperature dependent; therefore, the system temperature can be controlled by varying either steam pressure or temperature.

4) Steam components can be repaired or replaced by closing the steam supply, without the difficulties associated with draining and refilling a water system.

5.4 Briefly explain about the work principles of steam turbine

Steam turbine is one of machine types that use a method of external combustion engine. The working principle of steam turbine as follows:

I. Steam enters into the turbine through a nozzle. In the nozzle, heat energy from steam is converted into kinetic energy and the steam is expanding. Steam pressure at the exit of nozzle is smaller when compared with at the time of enter into nozzle, but otherwise the velocity of steam out from nozzle is greater than at the time of enter into the nozzle.

II. The steam gushing out of the nozzle is directed to the turbine blades with arches shaped and fitted around the wheel turbines. Steam flowing through gaps between the turbine blades is deflected towards following the curve of the turbine blades. The changes in steam velocity raise the force that encourages and then rotate the turbine wheel and shaft.

III. If the steam still has velocity when it leaves the turbine blades means that only some of the kinetic energy of steam is taken by the turbine blades which are running. More than one line of blade motion is installed to utilize the remaining kinetic energy when steam leaves the turbine blades.

IV. Before entering the second line of blade motion, so between the first row and second row blades motion is mounted one line fixed blade (blade guide) that allows you to change the direction of the steam velocity, so steam can enter the second line of blade motion in the right direction.

V. The velocity of steam when it leaves the last blade motion should be made as small as possible, so that the available kinetic energy can be utilized as much as possible. Thus the steam turbine efficiency is higher because of energy loss is relatively small.

V.5 Give the function of the cooling tower in cooling the tower in the condenser.

A cooling tower is a heat rejection device which extracts waste heat to

the atmosphere through the cooling of a water stream to a lower temperature.

Cooling towers may either use the evaporation of water to remove process heat and

cool the working fluid to near the wet-bulb air temperature or, in the case of closed

circuit dry cooling towers, rely solely on air to cool the working fluid to near the dry-

bulb air temperature.

CONCLUSION

A thermal power plant uses steam to spin turbines, which in turn feed electric generators. Most power plants in the world use thermal energy to operate. A thermal power plant is usually defined by the type of fuel used to heat the water and create steam. Coal, oil, and even solar and nuclear powers can be used to create the steam necessary to run a thermal plant.Many thermal plants operate on a partially closed loop, using what is known as a Rankine cycle. Water is heated by fuel, such as coal or nuclear power, until it becomes steam. Steam is passed through a series of chambers that make it stronger, hotter, and more powerful. The steam reaches the turbines and spins them, then is pushed through to a cooling storage area where it can condense back into water. The water can then be reused to create steam, completing the loop.