The document provides information about gas turbine power plants including:
- The basic working principle of a gas turbine power plant which uses a gas turbine coupled to a compressor and combustion chamber.
- Gas turbines operate on the Brayton cycle, which involves compressing air, adding heat through combustion, expanding the gas, and rejecting heat.
- Key advantages of gas turbines include greater power density, high reliability, and less maintenance compared to steam turbines. Disadvantages include lower efficiency and higher noise levels.
- Major applications are aircraft propulsion and electric power generation. Numerical examples are provided to calculate the performance of ideal and actual Brayton cycles.
A steam turbine is a prime mover in which the potential energy of the steam is transformed into kinetic energy and later in its turn is transformed into the mechanical energy of rotation of the turbine shaft
A steam turbine is a prime mover in which the potential energy of the steam is transformed into kinetic energy and later in its turn is transformed into the mechanical energy of rotation of the turbine shaft
Brayton cycle is a air standard cycle used to understand working of gas turbines. It is constant pressure cycle which shows how process are going in gas turbine.
A gas turbine, also called a combustion turbine, is a type of internal combustion engine. It has an upstream rotating compressor coupled toa downstream turbine, and a combustion chamber in-between. Energy is added to the gas stream in the combustor, where fuel is mixed with air and ignited. In the high-pressure environment of the combustor, combustion of the fuel increases the temperature. The products of the combustion are forced into the turbine section
Visit https://www.topicsforseminar.com to Download
Brayton or Joule cycle -P-V diagram and thermal efficiency. Construction and working of gas turbine i] Open cycle ii] Closed cycle gas turbine, simple circuit, Comparison, P-V & T-S diagramTurbojet and Turboprop Engine and Application
Gas turbine is an important topic usually studied in mechanical engineering, aeronautical engineering, power plant engineering, electrical engineering, and some other related engineering branches. The gas turbine is an air breathing heat engine, said to be the heart of the power plant produces electric power, by burning of gas (or) liquid fuels along with fresh air. The fresh air performs two main functions in gas turbine. The fresh air acts as a cooling agent for various parts of the power plants and gives required amount of oxygen for combustion of fuel. Topics covered in the ppt
Gas Turbines: Simple gas turbine plant- Ideal cycle, closed cycle and open cycle for gas turbines Efficiency, work ratio and optimum pressure ratio for simple gas turbine cycle Parameters of performance- Actual cycle, regeneration, Inter-cooling and reheating. the topics covered are almost same in all the universities. some problems were discussed in each and concept to make them understand clearly.
Brayton cycle is a air standard cycle used to understand working of gas turbines. It is constant pressure cycle which shows how process are going in gas turbine.
A gas turbine, also called a combustion turbine, is a type of internal combustion engine. It has an upstream rotating compressor coupled toa downstream turbine, and a combustion chamber in-between. Energy is added to the gas stream in the combustor, where fuel is mixed with air and ignited. In the high-pressure environment of the combustor, combustion of the fuel increases the temperature. The products of the combustion are forced into the turbine section
Visit https://www.topicsforseminar.com to Download
Brayton or Joule cycle -P-V diagram and thermal efficiency. Construction and working of gas turbine i] Open cycle ii] Closed cycle gas turbine, simple circuit, Comparison, P-V & T-S diagramTurbojet and Turboprop Engine and Application
Gas turbine is an important topic usually studied in mechanical engineering, aeronautical engineering, power plant engineering, electrical engineering, and some other related engineering branches. The gas turbine is an air breathing heat engine, said to be the heart of the power plant produces electric power, by burning of gas (or) liquid fuels along with fresh air. The fresh air performs two main functions in gas turbine. The fresh air acts as a cooling agent for various parts of the power plants and gives required amount of oxygen for combustion of fuel. Topics covered in the ppt
Gas Turbines: Simple gas turbine plant- Ideal cycle, closed cycle and open cycle for gas turbines Efficiency, work ratio and optimum pressure ratio for simple gas turbine cycle Parameters of performance- Actual cycle, regeneration, Inter-cooling and reheating. the topics covered are almost same in all the universities. some problems were discussed in each and concept to make them understand clearly.
PPTs covers portion of Unit 2 of Power Plant Engineering of Subject code ME6701.
PPTs covers Diesel Power Generation Plants, components, working principles of various system, advantages and disadvantagesand Comparision of various factors w.r.to Steam power Palnt, Diesel Plant, Nuclear, Hydraulic Power Plants.
Gas turbines, its cycle, working principles.
Combined Cycle Power plants.
Discussion on Brayton cycle, improvisions factors affecting effiencies.
Basic Scheme Open Cycle Gas Turbine Plant Aman Gupta
Gas Turbine Power Plant
A gas turbine, also called a combustion turbine, is a type of internal combustion engine.
Types of gas turbine power plant
1 Open cycle gas power plant
2 Closed cycle gas power plant
FellowBuddy.com is an innovative platform that brings students together to share notes, exam papers, study guides, project reports and presentation for upcoming exams.
We connect Students who have an understanding of course material with Students who need help.
Benefits:-
# Students can catch up on notes they missed because of an absence.
# Underachievers can find peer developed notes that break down lecture and study material in a way that they can understand
# Students can earn better grades, save time and study effectively
Our Vision & Mission – Simplifying Students Life
Our Belief – “The great breakthrough in your life comes when you realize it, that you can learn anything you need to learn; to accomplish any goal that you have set for yourself. This means there are no limits on what you can be, have or do.”
Like Us - https://www.facebook.com/FellowBuddycom
FellowBuddy.com is an innovative platform that brings students together to share notes, exam papers, study guides, project reports and presentation for upcoming exams.
We connect Students who have an understanding of course material with Students who need help.
Benefits:-
# Students can catch up on notes they missed because of an absence.
# Underachievers can find peer developed notes that break down lecture and study material in a way that they can understand
# Students can earn better grades, save time and study effectively
Our Vision & Mission – Simplifying Students Life
Our Belief – “The great breakthrough in your life comes when you realize it, that you can learn anything you need to learn; to accomplish any goal that you have set for yourself. This means there are no limits on what you can be, have or do.”
Like Us - https://www.facebook.com/FellowBuddycom
Immunizing Image Classifiers Against Localized Adversary Attacksgerogepatton
This paper addresses the vulnerability of deep learning models, particularly convolutional neural networks
(CNN)s, to adversarial attacks and presents a proactive training technique designed to counter them. We
introduce a novel volumization algorithm, which transforms 2D images into 3D volumetric representations.
When combined with 3D convolution and deep curriculum learning optimization (CLO), itsignificantly improves
the immunity of models against localized universal attacks by up to 40%. We evaluate our proposed approach
using contemporary CNN architectures and the modified Canadian Institute for Advanced Research (CIFAR-10
and CIFAR-100) and ImageNet Large Scale Visual Recognition Challenge (ILSVRC12) datasets, showcasing
accuracy improvements over previous techniques. The results indicate that the combination of the volumetric
input and curriculum learning holds significant promise for mitigating adversarial attacks without necessitating
adversary training.
Cosmetic shop management system project report.pdfKamal Acharya
Buying new cosmetic products is difficult. It can even be scary for those who have sensitive skin and are prone to skin trouble. The information needed to alleviate this problem is on the back of each product, but it's thought to interpret those ingredient lists unless you have a background in chemistry.
Instead of buying and hoping for the best, we can use data science to help us predict which products may be good fits for us. It includes various function programs to do the above mentioned tasks.
Data file handling has been effectively used in the program.
The automated cosmetic shop management system should deal with the automation of general workflow and administration process of the shop. The main processes of the system focus on customer's request where the system is able to search the most appropriate products and deliver it to the customers. It should help the employees to quickly identify the list of cosmetic product that have reached the minimum quantity and also keep a track of expired date for each cosmetic product. It should help the employees to find the rack number in which the product is placed.It is also Faster and more efficient way.
NO1 Uk best vashikaran specialist in delhi vashikaran baba near me online vas...Amil Baba Dawood bangali
Contact with Dawood Bhai Just call on +92322-6382012 and we'll help you. We'll solve all your problems within 12 to 24 hours and with 101% guarantee and with astrology systematic. If you want to take any personal or professional advice then also you can call us on +92322-6382012 , ONLINE LOVE PROBLEM & Other all types of Daily Life Problem's.Then CALL or WHATSAPP us on +92322-6382012 and Get all these problems solutions here by Amil Baba DAWOOD BANGALI
#vashikaranspecialist #astrologer #palmistry #amliyaat #taweez #manpasandshadi #horoscope #spiritual #lovelife #lovespell #marriagespell#aamilbabainpakistan #amilbabainkarachi #powerfullblackmagicspell #kalajadumantarspecialist #realamilbaba #AmilbabainPakistan #astrologerincanada #astrologerindubai #lovespellsmaster #kalajaduspecialist #lovespellsthatwork #aamilbabainlahore#blackmagicformarriage #aamilbaba #kalajadu #kalailam #taweez #wazifaexpert #jadumantar #vashikaranspecialist #astrologer #palmistry #amliyaat #taweez #manpasandshadi #horoscope #spiritual #lovelife #lovespell #marriagespell#aamilbabainpakistan #amilbabainkarachi #powerfullblackmagicspell #kalajadumantarspecialist #realamilbaba #AmilbabainPakistan #astrologerincanada #astrologerindubai #lovespellsmaster #kalajaduspecialist #lovespellsthatwork #aamilbabainlahore #blackmagicforlove #blackmagicformarriage #aamilbaba #kalajadu #kalailam #taweez #wazifaexpert #jadumantar #vashikaranspecialist #astrologer #palmistry #amliyaat #taweez #manpasandshadi #horoscope #spiritual #lovelife #lovespell #marriagespell#aamilbabainpakistan #amilbabainkarachi #powerfullblackmagicspell #kalajadumantarspecialist #realamilbaba #AmilbabainPakistan #astrologerincanada #astrologerindubai #lovespellsmaster #kalajaduspecialist #lovespellsthatwork #aamilbabainlahore #Amilbabainuk #amilbabainspain #amilbabaindubai #Amilbabainnorway #amilbabainkrachi #amilbabainlahore #amilbabaingujranwalan #amilbabainislamabad
Welcome to WIPAC Monthly the magazine brought to you by the LinkedIn Group Water Industry Process Automation & Control.
In this month's edition, along with this month's industry news to celebrate the 13 years since the group was created we have articles including
A case study of the used of Advanced Process Control at the Wastewater Treatment works at Lleida in Spain
A look back on an article on smart wastewater networks in order to see how the industry has measured up in the interim around the adoption of Digital Transformation in the Water Industry.
Automobile Management System Project Report.pdfKamal Acharya
The proposed project is developed to manage the automobile in the automobile dealer company. The main module in this project is login, automobile management, customer management, sales, complaints and reports. The first module is the login. The automobile showroom owner should login to the project for usage. The username and password are verified and if it is correct, next form opens. If the username and password are not correct, it shows the error message.
When a customer search for a automobile, if the automobile is available, they will be taken to a page that shows the details of the automobile including automobile name, automobile ID, quantity, price etc. “Automobile Management System” is useful for maintaining automobiles, customers effectively and hence helps for establishing good relation between customer and automobile organization. It contains various customized modules for effectively maintaining automobiles and stock information accurately and safely.
When the automobile is sold to the customer, stock will be reduced automatically. When a new purchase is made, stock will be increased automatically. While selecting automobiles for sale, the proposed software will automatically check for total number of available stock of that particular item, if the total stock of that particular item is less than 5, software will notify the user to purchase the particular item.
Also when the user tries to sale items which are not in stock, the system will prompt the user that the stock is not enough. Customers of this system can search for a automobile; can purchase a automobile easily by selecting fast. On the other hand the stock of automobiles can be maintained perfectly by the automobile shop manager overcoming the drawbacks of existing system.
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...Dr.Costas Sachpazis
Terzaghi's soil bearing capacity theory, developed by Karl Terzaghi, is a fundamental principle in geotechnical engineering used to determine the bearing capacity of shallow foundations. This theory provides a method to calculate the ultimate bearing capacity of soil, which is the maximum load per unit area that the soil can support without undergoing shear failure. The Calculation HTML Code included.
Overview of the fundamental roles in Hydropower generation and the components involved in wider Electrical Engineering.
This paper presents the design and construction of hydroelectric dams from the hydrologist’s survey of the valley before construction, all aspects and involved disciplines, fluid dynamics, structural engineering, generation and mains frequency regulation to the very transmission of power through the network in the United Kingdom.
Author: Robbie Edward Sayers
Collaborators and co editors: Charlie Sims and Connor Healey.
(C) 2024 Robbie E. Sayers
Saudi Arabia stands as a titan in the global energy landscape, renowned for its abundant oil and gas resources. It's the largest exporter of petroleum and holds some of the world's most significant reserves. Let's delve into the top 10 oil and gas projects shaping Saudi Arabia's energy future in 2024.
1. AE 2031 APPLIED THERMODYNAMICS S. Y. B. Tech.
GAS TURBINE
Prof. Aniket Suryawanshi
Asst. Prof. Automobile Engg. Dept.
R. I. T. Rajaramnagar
2. AE 2031 APPLIED THERMODYNAMICS S. Y. B. Tech.
OUTLINE OF CHAPTER
Working Principle and Applications of gas turbine.
Types of Gas turbine.
Modified Bryton cycle: Regeneration
Modified Bryton cycle: Reheat
Modified Bryton cycle: Intercooling.
Numerical on gas turbine work ratio and efficiency.
Gas turbine irreversibility's and losses.
3. AE 2031 APPLIED THERMODYNAMICS S. Y. B. Tech.
The simple gas turbine power plant mainly consist of a gas turbine coupled to a axial air
compressor and combustion chamber which is placed between the compressor and turbine in
the fuel circuit.
The gas turbine use gas as working medium by which heat energy is converted into
mechanical work or thrust. Gas is produced in the engine by the combustion of the fuel in the
combustion chamber.
Gas turbine is a rotary internal combustion engine.
Hot gases coming out from Combustion Chamber discharges over the blades of turbine
wheel. It causes the spinning action of the turbine blade about the shaft.
GAS TURBINE POWER PLANT - INTRODUCTION
4. AE 2031 APPLIED THERMODYNAMICS S. Y. B. Tech.
Atmospheric air is compressed to high pressure and temperature in the axial compressor.
This high pressure and temperature air is passed through nozzle in the CC, where fuel is
injected in the form of spray and combustion takes place. Resulting combustion products
enters in the expansion zone where it expands through a turbine to produce shaft work.
The exhaust gases leaving the turbine are finally discharged into the atmosphere.
Most of the power plant uses it to the run the auxiliaries devices of the plant such as cooling
fan, water pumps and the generator itself also.
GAS TURBINE POWER PLANTS – WORKING PRINCIPLE
5. AE 2031 APPLIED THERMODYNAMICS S. Y. B. Tech.
GAS TURBINE POWER PLANTS – ADVANTAGES
Compared to Steam-Turbine and Diesel Propulsion Systems, Gas Turbine offers :
• Greater Power for a given size and weight,
• High Reliability,
• Long Life,
• More Convenient Operation.
• Engine Start-up Time reduced from 4 hrs to less than 2 min…!!
• Less area requires for storage of fuel.
• Less maintenance cost,
• Simple construction, no need of boiler, condenser as in the other cases.
• Kerosene, Paraffin, benzene and powdered coal like cheaper fuels used.
• Less requirement of water, so can be installed at water scarcity area.
• Less pollution.
• Easy handling.
6. AE 2031 APPLIED THERMODYNAMICS S. Y. B. Tech.
GAS TURBINE POWER PLANTS – DISADVANTAGES
• Manufacturing a turbine blades is much difficult and costly.
• For same power o/p gas turbine produces 5 times more exhaust gases
than I. C. engine.
• Gas Turbine blades require special cooling system.
• Lower thermal efficiency as 15% to 20% in gas turbine as 25% to 30%
in I. C. engine. (66% of the power developed is used to drive the
compressor. Therefore the gas turbine unit has a low thermal efficiency.)
• High frequency noise from the compressor is objectionable.
• Requires Special metals and alloys to cast parts of the gas turbine. ( The
running speed of gas turbine is in the range of (40,000 to 100,000 rpm)
and the operating temperature is as high as 1100 – 12600C.)
7. AE 2031 APPLIED THERMODYNAMICS S. Y. B. Tech.
Two Major Application Areas :
1. Aircraft Propulsion
2. Electric Power Generation.
Electric Power GenerationAircraft Propulsion
GAS TURBINE POWER PLANTS – APPLICATIONS
8. AE 2031 APPLIED THERMODYNAMICS S. Y. B. Tech.
GAS TURBINE POWER PLANTS – APPLICATIONS
9. AE 2031 APPLIED THERMODYNAMICS S. Y. B. Tech.
GAS TURBINE POWER PLANTS – AEROSPACE APPLICATIONS
10. AE 2031 APPLIED THERMODYNAMICS S. Y. B. Tech.
• Air at ambient conditions is drawn into the compressor, where its temperature and
pressure are raised.
• The high pressure air proceeds into the combustion chamber, where the fuel is
burned at constant pressure.
• The high-temperature gases then enter the turbine where they expand to atmospheric
pressure while producing power output.
Some of the output power is used to drive
the compressor.
The exhaust gases leaving the turbine are
thrown out (not re-circulated), causing the
cycle to be classified as an open cycle.
BRAYTON CYCLE: OPEN CYCLE FOR GAS-TURBINE ENGINES
Gas turbines usually operate on an open cycle.
11. AE 2031 APPLIED THERMODYNAMICS S. Y. B. Tech.
• The compression and expansion
processes remain the same, but the
combustion process is replaced by a
constant-pressure heat addition
process from an external source.
• The exhaust process is replaced by a
constant-pressure heat rejection
process to the ambient air.
BRAYTON CYCLE: CLOSED CYCLE FOR GAS-TURBINE ENGINES
The open gas-turbine cycle can be modelled as a closed cycle, using the air-standard
assumptions.
12. AE 2031 APPLIED THERMODYNAMICS S. Y. B. Tech.
The ideal cycle that the working fluid undergoes in
the closed loop is the Brayton cycle. It is made up
of four internally reversible processes:
1-2 Isentropic compression;
2-3 Constant-pressure heat addition;
3-4 Isentropic expansion;
4-1 Constant-pressure heat rejection.
The T-s and P-v diagrams of an ideal Brayton cycle.
Note: All four processes of the Brayton cycle are
executed in steady-flow devices thus, they should be
analyzed as steady-flow processes.
BRAYTON CYCLE: IDEAL CYCLE FOR GAS-TURBINE ENGINES
13. AE 2031 APPLIED THERMODYNAMICS S. Y. B. Tech.
The energy balance for a steady-flow process can
be expressed, on a unit–mass basis, as
The heat transfers to and from the working fluid
are:
The thermal efficiency of the ideal Brayton cycle,
is the pressure ratio.where
BRAYTON CYCLE: IDEAL CYCLE THERMAL EFFICIENCY
Processes 1-2 and 3-4 are Isentropic,
P2 = P3 and P4 = P1.
1 1
2 2 3 3
1 1 4 4
T P P T
T P P T
, 1
1
1th Brayton
pr
14. AE 2031 APPLIED THERMODYNAMICS S. Y. B. Tech.
14
The combustion process is replaced by a
heat-addition process in ideal cycles.
Air-standard assumptions:
1.The working fluid is air, which continuously
circulates in a closed loop and always behaves
as an ideal gas.
2.All the processes that make up the cycle are
internally reversible.
3.The combustion process is replaced by a
heat-addition process from an external source.
4.The exhaust process is replaced by a heat-
rejection process that restores the working
fluid to its initial state.
Cold-air-standard assumptions: When the working fluid is considered to be
air with constant specific heats at room temperature (25°C).
Air-standard cycle: A cycle for which the air-standard assumptions are
applicable.
AIR-STANDARD ASSUMPTIONS
15. AE 2031 APPLIED THERMODYNAMICS S. Y. B. Tech.
Inlet conditions to a Brayton cycle are 1 bar and 300 K. The cycle pressure ratio is 6.5.
The temperature at the inlet to the turbine is 1500 K. Calculate the performance
parameters of the cycle.
Process 1→2 :
1
1.4 1
2 2 1.4
2
1 1
(300 ) 6.5
512.132
T P
T K
T P
K
rp =6.5
300 K
1500 K
Process 3→4 :
1
1.4 1
3 3 1.4
4
4 4
(1500 ) 6.5
878.679
T P
T K
T P
K
EXAMPLE ON IDEAL BRAYTON CYCLE
16. AE 2031 APPLIED THERMODYNAMICS S. Y. B. Tech.
Compressor Work :
2 1 2 1 1.005 (512.132 300) 213.19
.
C P
kJ kJ
W h h C T T K
kg K kg
Steady – Flow – Energy – Equation :
Heat Input :
3 2 3 2 1.005 (1500 512.132) 992.81
.
in P
kJ kJ
Q h h C T T K
kg K kg
Turbine Work :
3 4 3 4 1.005 (1500 878.679) 624.43
.
T P
kJ kJ
W h h C T T K
kg K kg
Heat Out :
4 1 4 1 1.005 (878.679 300) 581.57
.
out P
kJ kJ
Q h h C T T K
kg K kg
EXAMPLE ON IDEAL BRAYTON CYCLE
17. AE 2031 APPLIED THERMODYNAMICS S. Y. B. Tech.
Net Power In : 624.43 213.19 411.24T C
kJ
W W W
kg
Plant Efficiency :
411.24 /
41.42 %
992.81 /
th
in
kJ kgW
kJ kgQ
….ANS
Alternatively;
1.4 11
1.4
1 1
1 1 41.42 %
6.5
th
pr
….ANS
EXAMPLE ON IDEAL BRAYTON CYCLE…CNTD
18. AE 2031 APPLIED THERMODYNAMICS S. Y. B. Tech.
18
• Some pressure drop occurs during the heat-
addition and heat rejection processes.
• The actual work input to the compressor is more,
and the actual work output from the turbine is
less, because of irreversibilities or frictional
effects .
Deviation of actual compressor and turbine
behavior from the idealized isentropic behavior can
be accounted for by utilizing isentropic efficiencies
of the turbine and compressor.
Turbine:
Compressor:
ACTUAL GAS-TURBINE CYCLES…CNTD
19. AE 2031 APPLIED THERMODYNAMICS S. Y. B. Tech.
300 K
1500 K
rp =6.5
In the plant of Example 1, let the compressor and the turbine have the isentropic
efficiencies of 0.8 each. Calculate the performance parameters of the cycle.
From the earlier results,
kg
kJ
W
kg
kJ
Q
kg
kJ
W
KT
KT
T
in
C
43.624
81.992
19.213
679.878
132.512
4
2
EXAMPLE ON ACTUAL BRAYTON CYCLE
20. AE 2031 APPLIED THERMODYNAMICS S. Y. B. Tech.
12
12
12
12
12
12
,
,
TT
TT
TTC
TTC
hh
hh
W
W
A
S
AP
SP
A
S
ActC
TheorC
C
300 K
1500 K
rp =6.5
300
300132.512
8.0
2
AT
KT A 165.5652
Similarly;
S
A
SP
AP
S
A
TheorT
ActT
T
TT
TT
TTC
TTC
hh
hh
W
W
43
43
43
43
43
43
,
,
679.8781500
1500
8.0
4
AT KT A 94.10024
EXAMPLE ON ACTUAL BRAYTON CYCLE…CNTD
21. AE 2031 APPLIED THERMODYNAMICS S. Y. B. Tech.
Compressor Work :
kg
kJ
K
Kkg
kJ
TTChhW APAC 49.266300165.565
.
005.11212
Turbine Work :
kg
kJ
K
Kkg
kJ
TTChhW APAT 54.49994.10021500
.
005.14343
Heat Input :
kg
kJ
K
Kkg
kJ
TTChhQ APAin 51.939165.5651500
.
005.12323
Net Power In :
kg
kJ
WWW CT 05.23349.26654.499
Plant Efficiency : ….ANS%8.24
51.939
05.233
in
th
Q
W
EXAMPLE ON ACTUAL BRAYTON CYCLE…CNTD
22. AE 2031 APPLIED THERMODYNAMICS S. Y. B. Tech.
Heat Input :
kg
kJ
K
Kkg
kJ
TTChhQ APAin 51.939165.5651500
.
005.12323
Alternatively;
kg
kJW
W
C
SC
AC 49.266
8.0
19.213,
,
Actual Compressor Work :
kg
kJ
WW STTAT 54.49943.6248.0,, Actual Turbine Work :
Net Power In :
kg
kJ
WWW CT 05.23349.26654.499
Plant Efficiency : ….ANS%8.24
51.939
05.233
in
th
Q
W
EXAMPLE ON ACTUAL BRAYTON CYCLE…CNTD
23. AE 2031 APPLIED THERMODYNAMICS S. Y. B. Tech.
The fraction of the turbine work
used to drive the compressor is
called the back work ratio.
BWR is defined as the ratio of compressor work to the
turbine work
𝑟𝑏𝑤 =
𝑤𝑐𝑜𝑚𝑝𝑟𝑒𝑠𝑠𝑜𝑟
𝑤𝑡𝑢𝑟𝑏𝑖𝑛𝑒
The BWR in gas turbine power plant is very high, normally
one-half of turbine work output is used to drive the
compressor
BACK WORK RATIO
24. AE 2031 APPLIED THERMODYNAMICS S. Y. B. Tech.
The fraction of the turbine work that
becomes the net work is called the
work ratio.
Work Ratio is defined as the ratio of net work to the turbine
work
𝑟𝑤 =
𝑤 𝑛𝑒𝑡
𝑤𝑡𝑢𝑟𝑏𝑖𝑛𝑒
WORK RATIO
25. AE 2031 APPLIED THERMODYNAMICS S. Y. B. Tech.
The early gas turbines (1940s to 1959s) found only limited use despite their
versatility and their ability to burn a variety of fuels, because its thermal
efficiency was only about 17%. Efforts to improve the cycle efficiency are
concentrated in three areas:
1. Regeneration by preheating the air leaving the compressor with turbine
exhaust gases (regeneration or recuperation).
2. Reheating of gases after each stage of expansion to obtain more work
from the turbine (reheating).
3. Intercooling during compression stages to reduce the work input to the
compressor (intercooling).
IMPROVEMENTS OF GAS TURBINE’S PERFORMANCE
26. AE 2031 APPLIED THERMODYNAMICS S. Y. B. Tech.
BRAYTON CYCLE WITH REGENERATION
• Temperature of the exhaust gas leaving the turbine is
higher than the temperature of the air leaving the
compressor.
• The air leaving the compressor can be heated by the
hot exhaust gases in a counter-flow heat exchanger
(a regenerator or recuperator) – a process called
regeneration (Fig. 9-38 & Fig. 9-39).
• The thermal efficiency of the Brayton cycle
increases due to regeneration since less fuel is used
for the same work output.
Note:
The use of a regenerator is
recommended only when
the turbine exhaust
temperature is higher than
the compressor exit
temperature.
27. AE 2031 APPLIED THERMODYNAMICS S. Y. B. Tech.
Effectiveness of the regenerator,
Effectiveness under cold-air standard
assumptions,
Thermal efficiency under
cold-air standard
assumptions,
EFFECTIVENESS OF THE REGENERATOR
Assuming the regenerator is well insulated and changes in kinetic and potential
energies are negligible, the actual and maximum heat transfers from the exhaust
gases to the air can be expressed as
If written in terms of
temperatures only, it is
also called the thermal
ratio
28. AE 2031 APPLIED THERMODYNAMICS S. Y. B. Tech.
Thermal efficiency of Brayton cycle
with regeneration depends on:
a) ratio of the minimum to
maximum temperatures, and
b) the pressure ratio.
Regeneration is most effective at
lower pressure ratios and small
minimum-to-maximum temperature
ratios.
FACTORS AFFECTING THERMAL EFFICIENCY
Can regeneration be
used at high
pressure ratios?
29. AE 2031 APPLIED THERMODYNAMICS S. Y. B. Tech.
BRAYTON CYCLE WITH REHEATER
•A high pressure and a low pressure
turbine are used in a Reheat Brayton Cycle
•A reheater is a heat exchanger that increases
the power output without increasing the maximum
operating temperature but it does not increase
the efficiency of the cycle
•The capital cost to build a reheater alone cannot
be justified because the thermal efficiency
• does not increase.
30. AE 2031 APPLIED THERMODYNAMICS S. Y. B. Tech.
•Multistage compression with
intercooling improves the efficiency of
a compression process.
•A Brayton Cycle with Intercooling uses
two or more compression stages with one
or more intercoolers, as shown below.
The power requirement
for compression is reduced,
but QH also increases.
•Again, the capital cost to build
an intercooled compressor alone cannot
be justified because the thermal
efficiency does not increase.
BRAYTON CYCLE WITH INTERCOOLING
31. AE 2031 APPLIED THERMODYNAMICS S. Y. B. Tech.
A gas-turbine engine
with two-stage
compression with
intercooling, two-stage
expansion with
reheating, and
regeneration and its T-s
diagram.
For minimizing work input to compressor and
maximizing work output from turbine:
Tmax limited by materials,
Tmin limited by environment
BRAYTON CYCLE WITH INTERCOOLING, REHEATING & REGENERATION
32. AE 2031 APPLIED THERMODYNAMICS S. Y. B. Tech.
32
The work input to a two-stage compressor is
minimized when
a) equal pressure ratios are maintained across
each stage.
b) Complete intercooling is performed
This procedure also maximizes the turbine work
output.
Thus, for best performance we have,
CONDITIONS FOR BEST PERFORMANCE
𝑇3 = 𝑇1
33. AE 2031 APPLIED THERMODYNAMICS S. Y. B. Tech.
The net work output of a gas-turbine cycle
can be increased by either:
a) decreasing the compressor work, or
b) increasing the turbine work, or
c) both.
The compressor work input can be decreased
by carrying out the compression process in
stages and cooling the gas in between (Fig.
9-42), using multistage compression with
intercooling.
The work output of a turbine can be
increased by expanding the gas in stages
and reheating it in between, utilizing a
multistage expansion with reheating.
BRAYTON CYCLE WITH INTERCOOLING, REHEATING & REGENERATION
34. AE 2031 APPLIED THERMODYNAMICS S. Y. B. Tech.
As the number of compression and expansion
stages increases, the gas-turbine cycle with
intercooling, reheating, and regeneration
approaches the Ericsson cycle.
Intercooling and reheating always
decreases thermal efficiency unless
accompanied by regeneration. Why?
Therefore, in gas turbine power
plants, intercooling and reheating are
always used in conjunction with
regeneration.
BRAYTON CYCLE WITH INTERCOOLING, REHEATING & REGENERATION
35. AE 2031 APPLIED THERMODYNAMICS S. Y. B. Tech.
• The thermal efficiency of an ideal Brayton cycle
depends on the pressure ratio, rp of the gas
turbine and the specific heat ratio, k of the
working fluid.
• The thermal efficiency increases with both of
these parameters, which is also the case for
actual gas turbines.
PARAMETERS AFFECTING THERMAL EFFICIENCY
36. AE 2031 APPLIED THERMODYNAMICS S. Y. B. Tech.
• The highest temperature in the cycle is
limited by the maximum temperature
that the turbine blades can withstand.
This also limits the pressure ratios that
can be used in the cycle.
• The air in gas turbines supplies the
necessary oxidant for the combustion of
the fuel, and it serves as a coolant to
keep the temperature of various
components within safe limits. An air–
fuel ratio of 50 or above is not
uncommon.
PARAMETERS AFFECTING THERMAL EFFICIENCY
37. AE 2031 APPLIED THERMODYNAMICS S. Y. B. Tech.
PARAMETERS AFFECTING THERMAL EFFICIENCY
38. AE 2031 APPLIED THERMODYNAMICS S. Y. B. Tech.
PARAMETERS AFFECTING THERMAL EFFICIENCY
39. AE 2031 APPLIED THERMODYNAMICS S. Y. B. Tech.
PARAMETERS AFFECTING THERMAL EFFICIENCY