Course: CHE242: Fundamentals of Engineering thermodynamics (3 credits – Compulsory )
Course duration : 15 weeks (45hrs)
As taught in 2011/2012 session
Lecturers:
1
Eletta O.A.A.
Ph.D. Chemistry (Ilorin), M.Sc. Chemical Engineering (Lagos), B.Sc. Chemical Engineering, (Lagos)
Email: modeletta@unilorin.edu.ng
Consultation hours: Tuesday 2 -3 pm
2
Mrs L.T. Adewoye
B.Eng Chemical Engineering (Minna)
Email: adewoye.tl@unilorin.edu.ng
Developer: Dr O.A.A. Eletta
Location
1: Room 6: Chemical Engineering Building
2: Room 3: Chemical Engineering Building
Course Content
 Basic concepts
 General Treatment of thermodynamics laws
 Behaviour of pure substances and perfect gases
 Principles of conduction, convection and radiation
 Heat transfer in solid, liquid and gases
 Principles of construction and operation of thermal machinery and power plants
45h (T); C.
Course Description
Engineering Thermodynamics relates population growth to increasing use of energy in machines, it
looks into the effective use of energy resources and helps the engineer to deal quantitatively with
the analysis of machines which are used to convert energy into useful work. The study of
thermodynamics is primarily concerned with two forms of energy i.e heat and work.
Thermodynamics is divided into classical , chemical , statistics thermodynamics. The study is
concerned with the overall effect of energy transfer. It has application in a wide range of
engineering plants; steam turbine, reciprocating engines, rockets, jet engines, refrigerators, boilers,
condensers, cooling towers etc
Course Justification:
The need to use energy resources efficiently as, the science of thermodynamics helps us to deal
quantitatively with the analysis of machines which are used to convert energy into useful work and,
the fact that, the course has relevance / application in a wide range of day to day engineering plants
makes it necessary to understand the workings of these various plants, for example, the use of
turbine to generate electricity which we all consume in the homes, industries, etc, the working of a
refrigerator,; to answer the hows that comes to mind in the use of these engineering tools.
Course Objective(s):
The objective of this course is for the student to understand the fundamental principles underlying
the practice, use and management of engineering materials and energy in an engineering plant.
Course Requirements:
This is a compulsory course for all students studying Engineering. In view of this, students are
expected to have minimum of 75% attendance to be able to write the final examination.
Methods of grading:
No
Item
Score %
1.
CA ( quiz, assignment, test etc)
30
2.
Examination
70
3.
Total
100
Course Delivery Strategies:
The lecture will be delivered through face-to-face method. The students will be required to read
around the topics with tutorial sessions to complement the lectures.
LECTURES
Week 1 -2 : Basic concepts of thermodynamics
Objective: To introduce students to thermodynamics and, the general terms employed in
thermodynamics .
Description: the course outline, relevant textbooks mode of delivery of lecture will be introduced .
General terms employed in thermodynamics will be introduced and definition of terms will be done.
Study Questions
1. Why do we study thermodynamics
2. What do you understand by the following terms as employed in the study of
thermodynamics?
a. Boundary
b. System
3. Differentiate between statistical, chemical and classical thermodynamics
4. What do you understand by an open system
5. Give an example each of a closed and an open system
Reading list
1.
2
Gorgon, R & Yon, M., 2001, “Engineering Thermodynamics: Work and Heat Transfer”
Addison Wesley Longman , 4th ed. , 3 -14
2.
2
Sears, F.W &, Salinger, G.L,
ISBN81-7808-263-2
Thermodynamics, Kinetic Theory, and Statistical
Thermodynamics, Addison – Wesley Publishing coy, 3rd ed., 2 – 53
3.
1
Smith, J.M, Van Ness, H.C & Abbott, M.M., “Introduction to Chemical Engineering
Thermodynamics” 7th ed. 1 - 20
Week 3 - 7:
Objective:
The laws of Thermodynamics
To instruct students on the laws of Thermodynamics
Description: The three laws of thermodynamics have a major bearing on any engineering practice.
The first law which is concerned with the principle of conservation of energy will be
applied to closed systems which undergoes changes of state due to transfer of
work and heat across boundary. In the treatment of the second law, the idea of a
cycle efficiency is introduced. The various corollaries of the second law of thermo
will be discussed. The way in which entropy can be employed in the analysis of
steady – flow processes will be handled. The third law will just be introduced and its
application to the engineering practice.
Study Questions
Given the following data on air, attempt questions 1 and 2
Molar mass
28.97 kg/kmol
Universal gas constant Rn = 8.314 kJ/ kmol.K
Specific heat capacity at constant pressure, Cp = 1.005 kJ/kg.K
Specific heat capacity at constant volume, Cv = 0.718kJ/kg.K
1. Air at a pressure of 101.32 kPa and a temperature of 20oC occupies an initial volume of 1000
cm3 in a cylinder. The air is confined by a piston which has a constant restraining force so
that the gas pressure always remains constant. Heat is added to the air until its temperature
reaches 260oC. Calculate the heat added, the work done on the piston, and the change in
internal energy of the gas.
2. Twenty people attended a programme in a conference room which has floor dimensions
10m x 8m and a floor to ceiling height of 2.5 m. Each person gives up heat at the rate of 130
J/s. Assuming that the room is completely sealed off and insulated, calculate the air
temperature rise occurring in 15 minutes. Assume that each person occupies a volume of
0.07 m3. The initial pressure and temperature in the room are, 101.325 kPa and 21 oC
respectively.
3. 18 kg/s of air enter a turbine at 800 oC with a velocity of 100m/s. The air expands
adiabatically but not isentropically as it passes through the turbine and leaves with a velocity
of 130 m/s. It then passes through a diffuser where the velocity is reduced to a negligible
value and the pressure is increased to 1.01 bar. The air is exhausted to the atmosphere at
this pressure. If the process in the diffuser is assumed to be isentropic and the turbine
produces 3600kw , find the pressure of the air between the turbine and the diffuser.
4. Starting with the fact that, the volume of a substance is a function of T and P, show that
(ds/dV)T = /. Where  is the thermal coefficient of expansion and it is given by, 𝛼 =
1 𝜕𝑉
( )
𝑉 𝜕𝑇 𝑝
1 𝜕𝑉
and  the compressibility coefficient 𝛽 = − 𝑉 (𝜕𝑃)
𝑇
Reading list
1.
2
Gorgon, R & Yon, M., “Engineering Thermodynamics: Work and Heat Transfer” Addison
Wesley Longman , 4th ed. , 3 -14
2.
2
Sears, F.W & Salinger, G.L,
ISBN81-7808-263-2
Thermodynamics, Kinetic Theory, and Statistical
Thermodynamics, Addison – Wesley Publishing coy, 3rd ed., 2 – 53
3.
1
Smith J.M, Van Ness H.C &Abbott M.M., “Introduction to Chemical Engineering
Thermodynamics” Mc Graw – Hill International Edition, 7th ed. 1 - 20 ; 167 -198
ISBN007 – 12478-4
Week 8:
Mid Semester Test
Week 9:
Tutorials
Week 10 - 11: Principles of conduction, convection and radiation
Objectives : to understand the underlining principle of heat transfer in engineering practice and
hence be able to identify the various modes of heat transfer for specifics.
Description: there are three modes of heat transfer and this is dependent on the medium of
transfer. While transfer of heat through a solid is basically by conduction, transfer
through fluids is by convection. The transfer of heat through a vacuum is radiation.
Transfer of heat is usually from a point of higher temperature to one of lower
temperature. Temperature is an identifying characteristic of matter and, it is a
measure of its ability to transfer heat. When molecules collide against one another,
without moving from a fixed position, such as in a solid, the mode of heat transfer
here is referred to as conduction. The rate of heat flow by conduction is directly
proportional to the available area for heat transfer and the temperature gradient in
the direction of heat flow.
In convection, the molecules are free to move and circulate after each collision such
that, at a next collision, a molecule could exchange energy with a different molecule.
The hot body itself moves here carrying its heat with it. We could have natural or
forced convection.
Radiation involves the transfer of heat through a vacuum. The electromagnetic waves
emitted by a molecule because of its internal motion is absorbed by a second
molecule and converted to heat. The resulting mechanism of heat exchange in which
the internal energy of a substance is converted into radiant energy is called thermal
radiation.
Study questions
1. It is necessary to insulate a flat surface so that the rate of heat loss per unit area for the
surface per unit area does not exceed 250 W/m2. Given that the temperature difference
across the insulating layer is 385 oC, determine the thickness of insulation if (i) the insulation
is made from asbestos cement (k = 0.11W/mK) and (ii) the insulation is made from fireclay
(k = 0.84 W/mK)
2. A steam pipeline, 150/250 mm carries steam. The pipelie is covered with a layer of heat –
insulating material (k = 0.08 W/mK) of thickness 121 mm. given that the temperature drops
from 150 oC to 65 oC across the heat insulating material, calculate the rate of heat loss from
a unit length of the pipeline.
3. Water is to be heated from 35 oC to 53 oC at the rate of 27 kg/s. hot water at 85 oC is
available at the rate of 20 kg/s, for heating in a counter-current heat exchanger, calculate
the required heat transfer area if the overall heat transfer area is 1220 W/m2K.
Reading list
1.
2
Ghosal, S.K., Sanyal, S.K., & Datta A,
“Introduction to Chemical Engineering “ Tata Mc-
Graw Hill; 170 – 193
2.
2
Gorgon R & Yon M., “Engineering Thermodynamics: Work and Heat Transfer” Addison
Wesley Longman , 4th ed. , 501 -619
3.
1
4.
2
ISBN81-7808-263-2
Holman , “Heat Transfer” th ed. ; 170 – 177
McCabe W.L, Smith J.C, & Harriot P, “Unit Operations of Chemical Engineering” Mc Graw
Hill Book Co., 7th ed.; 281 – 426
ISBN007 – 12478-4
Week 12 - 14: Principles of construction and operation of thermal engines and power
plants.
Objectives:
At the end of the study, the students will be expected to be in a position to apply the
laws of thermodynamics to the vapour power cycles, heat pumps and refrigerator
cycles.
Description:
a common method of producing mechanical power involves the transfer of heat from
a reservoir to a working fluid which is taken through a thermodynamic cycle. The
choice of a power plant for a given purpose is determined largely by consideration of
operating cost and capital cost. Whatever the source of energy, the overall
thermal efficiency of a vapour cycle is quantified by the proportion of latent energy in
the fuel (source) which is converted to useful mechanical work.
Study questions
1. A carnot engine is operated between two heat reservoirs at temperatures of 400 K and
300 K; if the engine receives 1200 Cal from the reservoir at 400K in each cycle, how
many calories does it reject to the reservoir at 300 K. B.
If the engine is operated as
a refrigerator,(ie in reverse,) and receives 1200 Cal from the reservoir at 300K,, how
many calories does it deliver to the reservoir at 400 K. C.
How much work is done by
the engine in each case.
2. An ideal gas for which Cv is 3R/2 is the working substance of a carnot engine. During
the isothermal expansion, the volume doubles. The ratio of the final volume to the initial
volume in the adiabatic expansion is 5.7. The work output of the engine is 9 x 10 3 J in
each cycle,. Compute the temperature of the reservoirs between which the engine
operates.
3. A heat engine operates in a reversible cycle consisting of the following steps a.
Adiabatic compression from V1 at T1 to V2 at T2 b.
Heating at constant volume
V2 from temperature T2 to T3
c.
Adiabatic expansion from volume V2 at T3 to
volume V1 at temperature T4
d. Cooling at constant V1 from T4 to T1. Taking the
working substance to be n moles of an ideal gas for which Cv is a constant, show that ∆S
= 0 for a complete cycle.
Reading List:
1. 2Gorgon, R & Yon, M., “Engineering Thermodynamics: Work and Heat Transfer” Addison
Wesley Longman , 4th ed. , 207 – 363
2.
ISBN81-7808-263-2
2
Sears, F.W. & Salinger, G.L., “Thermodynamics, Kinetic theory and statistical
thermodynamics “Addison Wesley Publishing Coy; 4th ed , 111 - 145
3.
1
Smith, J.M, Van Ness, H.C &Abbott, M.M., “Introduction to Chemical Engineering
Thermodynamics” Mc Graw – Hill International Edition, 7th ed.; 161 – 163, 290 – 306, 326 –
327
ISBN007 – 12478-4
Week 15:
revision and examination