STUDY REPORTPower House (Services)

Submitted by: Sheikh Salman Hassan

Department: Electrical

Institution: FAST-NUCES, Karachi

PAKISTAN ORDINANCE FACTORY, WAH CANTT

Energy Requirements in POF

Total Capacity of Pakistan ordinance factory generation is about 36MW. POF generate only 11MW due to shortage of Gas supply. Total Consumption of POF factory and domestic consumers are about 26MW POF import remaining 15MW from WAPDA.

Ways of Generation of Electricity in POF

In POF production of electricity are made by two ways.

Self-generation of POF Import from WAPDA

Self-generation of POF

POF has its own self generation power plant from where POF produce about 10mw to 12MW through gas. In power generation house we produce electricity by steam which is produce with natural gas boilers. This steam runs turbines for electric generation.

Import from WAPDA

POF has a power plant that has the capacity to fulfill all the electricity requirement of factory as well as domestic use but due to the unavailability of the natural gas we import remaining electricity from WAPDA because consumption of POF is 28MW to 30 MW.

Production resources in POF

In POF we produce electricity through

Furnas oil or Natural Gas Steam Turbines

In POF three steam turbines are used which produce about 10MW, 8 MW and 8 MW.

10MW gas generation plant

10MW gas generation plant is totally programmable logic control based auto DCO system for the production of electricity.

7 Boilers are used for the production of 10MW electricity.

Pressure of steam will be 370 PSI or 25bar.

Temperature of inside boiler steam is 370oC.

Boiler Steam Generation

1 boiler generate about 24 tons / hours steam.

Boiler Control

Water Level Control Air Control Gas Control Steam flow Control

Boilers Working

Water Treatment plant Economizer Steam Turbines Safety valves Furnace

Block diagram of Boiler

Water Treatment plant

To increase the efficiency of turbines we convert hard water into soft water.

Storage Tank: In storage tank water is stored .lift pump is used to feed the water into Hot water tank. The temperature at storage tank is about 70-90oF.

Economizer

The Unburn gasses flows through the pipes which have water so we recycle heat and use this heat for increasing the temperature of water.

Safety valves

Three are three valves for the safety of turbine these valves operate at different pressure.

375 0C 380 0C

395 0C

When temperature reaches at 375 0C first valve operate and shows indication after 380 0C the furnace trip and automatic relays break the circuit automatically.

Safety valve:

It is used to relieve pressure and prevent possible explosion of a boiler .

Water level indicators:

They show the operator the level of fluid in the boiler, also known as a sight glass, water gauge or water column is provided.

Bottom blow-down valves:

They provide a means for removing solid particulates that condense and lay on the bottom of a boiler. As the name implies, this valve is usually located directly on the bottom of the boiler, and is occasionally opened to use the pressure in the boiler to push these particulates out.

Continuous blow-down valve:

This allows a small quantity of water to escape continuously. Its purpose is to prevent the water in the boiler becoming saturated with dissolved salts. Saturation would lead to foaming and cause water droplets to be carried over with the steam - a condition known as priming.

Hand holes: They are steel plates installed in openings in "header" to allow for inspections & installation of tubes and inspection of internal surfaces.

Steam drum

Steam drums internals, a series of screen, scrubber & cans (cyclone separators).

Low- water cutoff

It is a mechanical means (usually a float switch) that is used to turn off the burner or shut off fuel to the boiler to prevent it from running once the water goes below a certain point. If a boiler is "dry-fired" (burned without water in it) it can cause rupture or catastrophic failure.

Surface blow-down line

It provides a means for removing foam or other lightweight non-condensable substances that tend to float on top of the water inside the boiler.

Circulating pump

It is designed to circulate water back to the boiler after it has expelled some of its heat.

Feed-water checks valve or clack valve

A non-return stop valve in the feed water line. This may be fitted to the side of the boiler, just below the water level, or to the top of the boiler.

Top feed

A check valve (clack valve) in the feed water line, mounted on top of the boiler. It is intended to reduce the nuisance of lime scale. It does not prevent lime scale formation but causes the lime scale to be precipitated in a powdery form which is easily washed out of the boiler.

12 De-super-heater tubes or bundles

A series of tubes or bundles of tubes in the water drum or the steam drum designed to cool superheated steam. Thus is to supply auxiliary equipment that doesn't need, or may be damaged by, dry steam.

Water tube boiler fire tube boiler

This hot water enter into the main boiler .the boilers have interlinking tubes. Furnace is inside the upper and lower drum boiler is close terminal steam is produce inside the furnace has a temperature of about 3700C and has a pressure of 370 PSI.

Steam Turbines

As we know as the temperature of furnace increase then PRM of turbine also increase measns they have directly proportional to each other.

Turbines revolute at the speed of 8000 RPM and these turbines tripping at the speed of 9000 RPM.

There are three types turbines these are as follows..

Impulse turbines Reaction turbines Impulse reaction turbines (Compound turbine)

In POF Impulse reaction turbines (Compound turbine) is used .these turbines have two sides

LT side which has low pressure HT side of turbine which has High temperature

In POF three steam turbines are used which produce about 10MW, 5 MW and 8 MW.

10MW gas generation plant

10MW gas generation plant is totally programmable logic control based auto DCO system for the production of electricity.

7 Boilers are used for the production of 10MW electricity.

Pressure of steam will be 370 PSI or 25bar.

Temperature of inside boiler steam is 370oC.

Alternator

Alternator operate son the principle of faraday law of electro magnetism.

According to faraday law when moving coil rotate on the permanent magnet then a flux is generate at its surrounding and this flux induced voltage at its surrounding.

Alternator’s moving coil has a speed of about 15000 RPM.Alternator’s coil is moved by the small generator which also called as excitatory.

Excitation

Excitator acts like a small generator it has a slip ring, carbon brushes and a permanent magnet as generators have Reduction gear is used to reduce the speed of the moving coil to 1500 RPM.