steam plant senior.doc

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1. OBJECTIVES

The main objectives of this experiment are;

To determine the performance characteristics of a steam plant. To demonstrate thermodynamic principles as applied to laboratory scale steam plant.

To demonstrate the conversion of energy from one form to another and the

measurement of mechanical power.

2. INTRODUCTION

The strength of the steam engine for modern purposes is in its ability to convert raw heat into

mechanical work. Unlike the internal combustion engine, the steam engine is not particular

about the source of heat. Since the oxygen for combustion is unmetered, steam engines burn

fuel cleanly and efficiently, with relatively little pollution. ne source of inefficiency is that

the condenser causes losses by being somewhat hotter than the outside world. Thus any

closed!cycle engine will always be somewhat less efficient than any open!cycle engine,

because of condenser losses.

"n this experiment, the students had been exposed with the mechanism of steam engine by

using steam plant laboratory model unit. The steam plant consists of several component

include a boiler, a steam engine, a condenser and a feed pump. "n large power plants, steam

turbine are used but for a small scale laboratory set up, a steam engine is used. The

applications of steam engines can be divided into # categories which are as stationary engines

and also as vehicles engines. $or stationary engines, its applications include in winding

engines, rolling mill engines, thermal power stations engines and many others while for

vehicles engines, its applications are traction engine, steam aircraft, steam rockets,steamboat,

steamshipand many others.

The steam plants of today are a combination of complex engineered systems that work to

produce steam in the most efficient manner that is economically feasible. "n large power

plants, steam turbines are used but for a small %scale laboratory set up, a steam engine is

used. "n every situation, the steam power plant must first obtained heat. The heat re&uired to

produce the steam is a significant operating cost that affects the ultimate cost of end the

product.
http://en.wikipedia.org/wiki/Rolling_millhttp://en.wikipedia.org/wiki/Traction_enginehttp://en.wikipedia.org/wiki/Steam_aircrafthttp://en.wikipedia.org/wiki/Steam_rockethttp://en.wikipedia.org/wiki/Steamboathttp://en.wikipedia.org/wiki/Steamshiphttp://en.wikipedia.org/wiki/Rolling_millhttp://en.wikipedia.org/wiki/Traction_enginehttp://en.wikipedia.org/wiki/Steam_aircrafthttp://en.wikipedia.org/wiki/Steam_rockethttp://en.wikipedia.org/wiki/Steamboathttp://en.wikipedia.org/wiki/Steamship


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'eat is supplied to the boiler via two immersion heaters () k* each+. The water in the boiler

must be clean and free from minerals. The water is pumped to the boiler from a reservoir. The

boiler raises saturated steam to a maximum bars.

- steam engine is a heat engine that performs mechanical work using steam as its working

fluid. The steam engine is a totally enclosed, two cylinders, and single acting trunk piston

with nominal output of #/ * at #/// rev per min. The steam is expended in the steam

engine to produce useful work.

The condenser condenses the exhaust steam from the steam engine from saturated steam into

water. The water is then return to the reservoir and pump back into the boiler and the cycle

continues.

Figure 10 Steam motor and energy conservation test set

3. THEORY


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The cycle of operations in a heat engine is based on 1ankine 2ycle. The 1ankine cycle is a

thermodynamic cycle which converts heat into work. The heat is supplied externally to a

closed loop, which usually uses water as the working fluid. -lmost all coal and nuclear power

stations use this cycle for power generation. "t is named after *illiam 3ohn 4ac&uorn

1ankine, a Scottishpolymath. "t is more closely approximates to the cycle of a real steam

engine if been compared to the 2arnot cycle where it predicts a lower ideal thermal efficiency

than the 2arnot cycle.

"n the 1ankine cycle, heat is been added at constant pressure (5+, at which water is

converted in a boiler to the superheated steam condition that causes the steam expands at

constant entropy to a pressure (5#+ in a condenser; the water so formed is compressed at

constant entropy to 5 by a feed pump. The cycle consists of four processes as been listed

below0

to #0 "sentropicexpansion (Steam turbine+

# to )0 "sobaric heat rejection (2ondenser+

) to 0 "sentropic compression (5ump+

to 0 "sobaric heat supply (6oiler+

Figure 20 1ankine cycle

4. METHODOLOGY
http://en.wikipedia.org/wiki/Thermodynamicshttp://en.wikipedia.org/wiki/William_John_Macquorn_Rankinehttp://en.wikipedia.org/wiki/William_John_Macquorn_Rankinehttp://en.wikipedia.org/wiki/Polymathhttp://www.taftan.com/thermodynamics/ISENPROC.HTMhttp://www.taftan.com/thermodynamics/ISOBARPR.HTMhttp://en.wikipedia.org/wiki/Thermodynamicshttp://en.wikipedia.org/wiki/William_John_Macquorn_Rankinehttp://en.wikipedia.org/wiki/William_John_Macquorn_Rankinehttp://en.wikipedia.org/wiki/Polymathhttp://www.taftan.com/thermodynamics/ISENPROC.HTMhttp://www.taftan.com/thermodynamics/ISOBARPR.HTM


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The engine was been run at the constant speed #/// rev per min ! at varying engine

load with0

a+ The right hand spring balance was been loaded with # 7 stages to #/ 7

b+ The boiler pressure was varied to achieve constant speed (8 // rev. min!+

The parameter was recorded in the data sheet (The volume of condensate was

collected in a measuring cylinder with minute9s interval for the condensate flow

rate.+

The results were been analy:ed.

-fter used0

a+ The electrical and water supplies were disconnected

b+ The boiler was allowed to cool down and the boiler drain valve was opened

c+ The water from the apparatus was drained

d+ The temperature display was switched off.

7ote0 7ever open the boiler drain valve while there is a pressure or high

temperature inside the boiler.


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5. RESULTS

T!"e 10 1esult that obtains for the different spring load.

S#ri$g

L%&

B%i"er

're((ure

'1)!r*

B%i"er

Te+#

T1),C*

E$gi$e

I$"e-'re((ure

'2)!r*

E$gi$e

S#ee&

N)re/+i$*

C"%ri+e-er

Te+#

T2),C*

C%$&e$(er

C%%"i$gH2O I$"e-

T3),C*

C%$&e$(er

C%%"i$g H2OOu-"e-

T4 ),C*

C%$&e$(-e

F"%0 R-e

+()g/(*

E"e-ri"

'%0er 1

)*

C%$&e$(-e

Te+#

T5),C*F1

)N*

F2

)N*

.< #.= #>./ .? #/@# //.@ #>. )?. .?=@ x /!)


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u"i-6 %7 (-e+ i$

!%i"er 8

B%i"er e77iie$6 9 '%0er %u-#u- %7 -:e

e$gi$e1

R$i$e 6"e e77iie$6

9R

T:er+" e77iie$6 9T:

/.>> @/.>> =./@< .@< ./@ x /!)

/.>> @?.


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H7)J/g* H7g)J/g* Hg )J/g* H1 H3

@


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Figure 2;The graph steam flow rate vs power output.

> with

the boiler efficiency of about @/.>> E. The power delivered by the engine calculated to be


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=./@> at )#.= bars and )#.=D2 of boiler condition. The boiler efficiency was above than

perfect condition in operation, which calculated at @?.


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Since the increasing of the $ and constant value of $#, the boiler efficiency is increasing.

The basic idea to increase the efficiency of the 1ankine 2ycle is increase the temperature at

which heat is transferred to the working fluid in the boiler or decrease the temperature at

which heat is rejected from the working fluid in the condenser. "n this steam plant, there are

three ways to increase efficiency based in simple ideal 1ankine 2ycle which is lowering the

2ondenser 5ressure (Fower T low, avg+, lowering the operating pressure of the condenser which

automatically lowers the temperature of the steam and thus the temperature at which heat is

rejected. Fast but not least, superheating the Steam to 'igh Temperatures ("ncrease T high, avg+

and increasing the 6oiler 5ressure ("ncreases T high, avg+.

$rom the data and results obtained, crystal clearly shows the power output from the engine is

increasing by the increment of the spring load difference. 'igher load also lead to higher

boiler efficiency with a direct relation to the 1ankine and thermal efficiency as well.

=. CONCLUSION

6ased on the result, there is a proven that the steam plant can produced a high &uality of

water vapor mixture, which is around >>. E. $rom the relationship, there is significant

increment on the power input of the engine when the load is increasing. Thus, we can

conclude that the higher the load, the higher the power output from the engine. This direct

relationship also linked to the boiler, 1ankine and thermal efficiency which the higher the

load, the better the efficiency.


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>. REFERENCES

-. 3ack *innick , 2hapter @, 5ower production, Chemical Engineering Thermodynamics

(1997),pg.=>.

6. *oodruff. C. 6.et.al.(#//


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?. S?M'LE C?LCUL?TION FOR LO?D [email protected]

2alorimeter temperature (hg+

Aata from table -!;

Temperature hg/ #=@=

//.= x

/ #=@@.=

x% #=@=IIIII J III//.= % //III

#=@@.= % #=@= //. ! //

x J #=@=.>=

* u"i-6 8

x J #=@=.>= %

hJ (#==.==+

hJ #=@@.=/

!* B%i"er e77iie$6 9B


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4s J )# ImlI x II minII x IkgII

4in =/sec ///ml

J #.# x /!)kgBsec

J #.# x /!) kgBsec (#=@@.!


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