Koya University Faulty of Engineering

School of Chemical & Petroleum Engineering

Chemical Engineering department

EXPERIMENT NUMBER FOUR

Marcet Boiler

Thermodynamics

Marcet Boiler

Instructor: Mr.Rebwar & Mr.Omer

Author Name: Aree Salah Tahir

Experiment Contacted on: 21/Jen/2013

Report Submitted on: 28/Jen /2013

Group:A

List of content:

Abstract ………………………………….….2

Objectives……………………………….…...3

Introduction …………………………………4

Background Theory ……………………...….5

Method ………………………………………6

Equipment and components used……………7

Calculation…………………………………...8

Discussion …..…………………....……9 &10

References …………………………………11

Abstract:

pressure the between relationship the determine to out carried was experiment This

experiment this that Besides equilibrium. in steam saturated of temperature the and

was Boiler market The curve. pressure vapor the demonstrate to done also was

increases. also temperature the increases, pressure the When .experiment this for used

The proportional. directly is temperature and pressure of relationship the Therefore,

measured dT/dP The slope. the calculate to used were data the and formulae derived

measured values the Theoretically, table. steam the in data the with compared was

the points, certain at However, values. predicted the with same the almost be should

}1{experiment. the in made errors the of because may This same. the not are values

2

OBJECTIVE:

The main aim of this experiment is to obtain a slope of saturated temperature and

pressure of steam, in equilibrium with water, between 0 and 14 bars. These results

are then compared to the theoretical values obtained from published steam tables.

A value for the constants as well as the maximum temperature if heating were

continued miscalculated. Moreover, after an expression for the time taken for the

temperature to reach ascertain value is derived.{2}

3

Introduction:

work and heat as such energies of interchange the with deals Thermodynamics

a undergoes system the when occurs which surroundings the and system between

direct a has system a in energy of gain or loss The cooling). or heating( process

thermodynamic important most the of Two properties. thermodynamic its on impact

and pressure are experiment) this in investigated (being fluids of properties

when i.e. system a of energy the in changes to response in vary both that temperature

published from obtained values theoretical The .system the by gained or lost is energy

market the conducting while obtained readings the to compared be to are tables steam

values. two the of divergence the for analysis further giving while experiment, boiler

to used was unit Boiler Marcet P5700 Cussons a experiment, this of purpose the For

its inside vapor water of pressure and uretemperat the measure and fluid the heat

water of properties thermodynamic in change the about conclusions ,Thus vessel.

in used usually are units boiler Marcet drawn. where processes different undergoing

between relationship the understand to experiments lab and demonstrations classroom

water of point boiling the on effects their and pressure and temperature of changes the

an such as widely vary applications industry However state). (equilibrium

well as gasifies ,utilities cooking different plants, power in used be can arrangement

}3{boiler water a as boiler market the utilizing as

4

BACKGROUND THEORY:

An ideal gas obeys the equation of state that the pressure, specific volume or density, and absolute temperature with mass of molecule and the gas constant, R. PV = mRTM Where, P = Absolute pressure V = Volume n = Amount of substance (moles) R = Ideal gas constant T = Absolute temperature (K) However, real gas does not absolutely obey the equation of state. A few changes on the ideal gas equation of state allow its application in the properties of real gas. When energy increases within water, the increasing of activities among the molecules enables the increase in the number of molecule escape from the surface until an equilibrium state is reached. The state of equilibrium depends on the pressure between the water surface and steam. At lower pressure, the molecules become easier leaving the water surface while less energy required in achieving the state of equilibrium (boiling point). The temperature where equilibrium occurs at a given pressure level is called saturated temperature. The Marcet Boiler is used to investigate the relationship between the pressure and temperature of saturated steam in equilibrium with water at all temperature levels between the atmospheric pressure and 8 bars. The experimental slope (dT/dP)SAT obtained is compared to the theoretical value determined through calculation from the steam table.{4}

5

Method: 1/Prepare the bench top unit as described in section 2.2.

2/Switch on the unit at the master switch.

3/Switch on the heater at the heater switch and heat up the boiler.

4/Log the boiler pressure and temperature values in increments of approximately

0.5 bar.

5/Enter the measured values in the diagram.

6/Compare your own measurements with the values from the literature.

6

EQUIPMENT & COMPONENTS USED:

1/ safety valve,

2/ boiler with insulating jacket,

3/ Bourdon tube pressure gauge,

4/ switch cabinet with temperature display,

5/ drain valve,

6/ heater,

7/ overflow,

8/ temperature sensor

{5}

7

Calculation:

NO. Temperature

(K) Pressure

(kpa) Specific volume

/kg3 (Vg) m Latent heat of evaporation

kg/KJ ) fgH(

1 373 131.3

2 378 151.3

3 383 181.3

4 388 201.3

5 393 241.3

8

131.3151.3

181.3201.3

241.3

0

50

100

150

200

250

300

370 375 380 385 390 395

Pre

ssu

re (

KP

a)

Teperature (K)

Temperature and Pressure Plot

Discussion:

In the experiment the pressure and temperature are compared by the graphs

and tabulated results as for the pressure and temperature are compared and

result showed that by experiment. Thethe throughoutit was almost constant

error made during the experiment can be analyzed and test,comparing each

.effetelysupport the discussion

The error percentage should be around 10 - 20 % because there`s small difference between the actual and ideal value`s we got. Source of experiment error

Measurement reading accuracy

Room temperature and pressure

The stability of the materials

If the air is not expelled the correct equilibrium put the air in the vessel out e W

measurements between the steam and boiling water will not be obtained. Due

will be required to ewater temperatur to the partial pressure of air a lower

.raise the pressure

We use distilled water in this experiment because distilled water prevents corrosion

boiling point is W.Dother water increase boiling point (and impurities in vessel in the

).0 but other water with impurity reaches 110c 0100c

we use over flow valve to pure extra water in the vessel

9

Temperature-pressure diagram of water red: sublimation curve, green: boiling point curve, blue: melting point curve; 1 triple point, 2 boiling point, 3 critical point

{6}

10

References:

1/http://www.slashdocs.com/pwxyx/marcet-boiler-lab-report.html

demia.edu/4916263/Marcet_Boiler_Lab_Report_Shahda_Mazin_http://www.aca/2

-Taie_H00113228_Mechanical_Engineering_-Abduljabbar_Al

_2nd_year_Supervised_by_Dr._Mehdi_Nazarinia

3/http://www.academia.edu/4916263/Marcet_Boiler_Lab_Report_Shahda_Mazin_Abduljabbar_Al-Taie_H00113228_Mechanical_Engineering_-_2nd_year_Supervised_by_Dr._Mehdi_Nazarinia

1059371.html-Experiment-ww.studymode.com/essays/Boilerhttp://w4/

5/http://www.gunt.de/networks/gunt/sites/s1/templates/scripts/picDetail.php?actEntry

=3436&lang=1&dir=06020400&src=Zeichnung.jpg&color=FF6633&software=0

http://answers.yahoo.com/question/index?qid=20071016234129AAM7qEX/6

boiler.html-http://yoursteacher.blogspot.com/2012/05/marcets

11