Energy and Exergy Analysis of a country sectors

1. Sectoral Energy and Exergy
Analysis
Mostafa Ghadamyari
Advanced Thermodynamics Course
Mechanical Engineering Department – Energy Conversion
Tarbiat Modares University
Spring 2014

2. “
”German theoretical physicist who pioneered developments in atomic and quantum physics
Thermodynamics definition

3. “
”
Energy, Entropy and Exergy concepts stem
from thermodynamics and are applicable to
all fields of science and engineering.
Introduction

4. Energy, Exergy & Entropy
o Entropy and Exergy are also used in other fields (such as statistics
and information theory), and Therefore they’re not subsets of
energy.
o Some forms of Energy (such as shaft work) are entropy-free, and
thus entropy subtends only part of energy.
o Likewise, Exergy subtends only part of the energy field since some
systems (such as air at atmospheric conditions) possess energy
but no exergy.

5. Energy, Exergy & Entropy
o Most thermodynamic systems
(such as steam in a power
plant) possess energy,
entropy and exergy, and thus
appear at the intersection of
these three fields.
o So we can have Energy
Analysis, Exergy Analysis &
Entropy Analysis according to
system

6. Applying Exergy Analysis to MacroSystems
• Exergy is the ‘fuel’ of dissipative
systems, i.e., systems that are sustained
by converting energy and materials.
• Examples include a living cell, an organism, an
ecosystem, and the earth’s surface with its
material cycles.
• Societies are also dissipative systems,
and can therefore be assessed with
exergy analysis.

7. Exergy Analysis helps us to:
• Improving the efficiency of energy resource utilization.
• Assessing the locations, types and true magnitudes of wastes and losses.
• Distinguishing between high- and low-quality energy resources and
services, and better matching the quality of energy required for a service
with the quality of the energy supplied.
• High Temperature Resource -> High Temperature application
• Determining whether or not and by how much it is possible to design more
efficient energy systems by reducing inefficiencies.
• Reducing the impact of energy resource utilization on the environment.

8. Energy Loss

9. Energy flow model for a country
• First introduced in a landmark
paper by Reistad (1975), who
applied it to the U.S.
• Since then, several other countries
been examined using modified
versions of this approach:
• Canada (Rosen,1992)
• Japan, Finland and Sweden (Wall,
1990, 1991)
Italy (Wall et al., 1994)
• Turkey (Ozdogan and Arikol, 1995;
Rosen and Dincer, 1997b)
• …

10. Backgrounds
• Relations:
• 𝜼 =
𝑬𝒏𝒆𝒓𝒈𝒚 𝒊𝒏 𝒑𝒓𝒐𝒅𝒖𝒄𝒕𝒔
𝑻𝒐𝒕𝒂𝒍 𝒆𝒏𝒆𝒓𝒈𝒚 𝒊𝒏𝒑𝒖𝒕
• 𝚿 =
𝑬𝒙𝒆𝒓𝒈𝒚 𝒊𝒏 𝒑𝒓𝒐𝒅𝒖𝒄𝒕𝒔
𝑻𝒐𝒕𝒂𝒍 𝒆𝒙𝒆𝒓𝒈𝒚 𝒊𝒏𝒑𝒖𝒕
• Heating:
• Electrical:
• 𝜼 𝒉,𝒆 = 𝑸 𝒑/𝑾 𝒆
• 𝝍 𝒉,𝒆 = 𝟏 −
𝑻 𝟎
𝑻 𝒑
𝑸 𝒑
𝑾 𝒆
= 𝟏 −
𝑻 𝟎
𝑻 𝒑
𝜼 𝒉,𝒆
• Fuel:
• 𝜼 𝒉,𝒇 = 𝑸 𝒑/𝒎 𝒇 𝑯 𝒇
• 𝝍 𝒉,𝒇 ≅ 𝟏 −
𝑻 𝟎
𝑻 𝒑
𝜼 𝒉,𝒇
• Work production:
• Electrical:
• 𝜼 𝒎,𝒆 = 𝑾/𝑾 𝒆
• 𝝍 𝒎,𝒆 = 𝜼 𝒎,𝒆
• 𝑃 𝑒𝑛𝑣 = 1𝑎𝑡𝑚
• 𝑇 𝑒𝑛𝑣 = 25𝐶

11. Analysis of the
residential/commercial
sector
Case study: Turkey (Utlu 2005)

12. Energy usage in Iran vs Turkey
Turkey Iran
Population 76M 77M

13. Energy usage in Turkey
Industrial
42%
Residental
31%
Transportation
19%
Agricultur
al
5%
Non-energy
3%
TURKEY 2003 ENERGY USE

14. Residential/Commercial sector model
Residential Commercial
space heating 45% 42%
water heating 27% 30%
cooking 9% 11%
electrical
appliances
19% 17%
Share of Primary Energy Usage:

15. Utilization of Energy in Turkish Residential
Sector
• Turkey Residential energy
consumption:
• 41.5% Renewable
• 38.7% Fuel
• 19.8% Electricity
• Wood: Sustainable & Renewable
Energy Source

16. Wood - Multi-Fuel & Boiler Stoves
• Output to room: 2.8 kW
• Output to water: 9 kW
• No. of radiators in average
installation: 3-4
• Based on Double Panel Radiators
1m*0.6m
• Dimensions: 0.5m 0.5m 0.5m
• Weight: 95kg
• Price: ~1700$ (Include VAT,
DELIVERY

17. Energy utilization values of TRCS
• We need fraction of energy use in
each application
• Source:
• Utlu Z. Analysis of Turkey’s
Sectoral Energy and Exergy
Utilization Efficiency by 2023.
Ph.D. thesis in Solar Energy
Institute (Advisor: A.Hepbasli ),
Graduate School of Natural
andApplied Sciences, Ege
University, Izmir, Turkey; 2003 [in
Turkish].
• Usually published by Institute of
statistics

18. Step 1: Estimate end-use energy efficiency
• Step 1: Energy efficiencies
(First law efficiencies) are
estimated.
• Source:
• Utlu Z. Analysis of Turkey’s
Sectoral Energy and Exergy
Utilization Efficiency by 2023.
Ph.D. thesis in Solar Energy
Institute (Advisor: A.Hepbasli ),
Graduate School of Natural
andApplied Sciences, Ege
University, Izmir, Turkey; 2003
[in Turkish].

19. Step 2: Calculate Exergy Efficiency
Example: Cooking
Energy efficiency:
𝜀1,𝑐𝑜𝑜𝑘𝑖𝑛𝑔 = 50%
Cooking temperature: 120C
Ambient temperature: 20C
𝜀2,𝑐𝑜𝑜𝑘𝑖𝑛𝑔 = 50% × 1 −
273+20
273+120
= 12.7%

20. Exergy efficiencies
• Exergy efficiencies are
calculated as shown in
the table.

21. Step 3 : Overall Application efficiency
• Overall energy efficiency:
• 𝜀1𝑜 = (𝑎1 𝜀1𝑐
+ 𝑎2 𝜀2𝑐+…+𝑎2 𝜀2𝑐)/100
• Overall exergy efficiency:
• 𝜀2𝑜 = (𝑎1 𝜀2𝑐
+ 𝑎2 𝜀2𝑐+…+𝑎3 𝜀2𝑐)/100

22. Step 3 : Overall Application efficiency
• Cooking:
• 𝜀1𝑜 =
91.7∗50+7.5∗50+0.3∗80+0.3∗22
100
= 49.9
• 𝜀2𝑜 =
91.7∗10.7+7.5∗10.8+0.3∗17.2+0.3∗4.5
100
= 10.68

23. Overall Energy and Exergy efficiency
• Overall application Energy &
Exergy efficiencies are
calculated as shown in the
table.
• Overall Sector Energy &
Exergy efficiencies:
• 𝜀1𝑜 = (𝜀1𝑒 𝑒 𝑟𝑐 + 𝜀1𝑓 𝑓𝑟𝑐 + 𝜀1𝑟 𝑟𝑟𝑐)
/(𝑒 𝑟𝑐 + 𝑓𝑟𝑐 + 𝑟𝑟𝑐)
• 𝜀2𝑜 = (𝜀2𝑒 𝑒 𝑟𝑐 + 𝜀2𝑓 𝑓𝑟𝑐 + 𝜀2𝑟 𝑟𝑟𝑐)
/(𝑒 𝑟𝑐 + 𝑓𝑟𝑐 + 𝑟𝑟𝑐)

24. Step 4 : Overall sector efficiency
• Residential-Commercial Efficiency:
• Space Heating: 45%
• Water Heating: 27%
• Cooking: 9%
• Electrical: 18%
• 𝜀1𝑜 =
50.32∗45+60.43∗27+40.32∗9+80.98∗18
100
= 57.16
• 𝜀2𝑜 =
2.65∗45+3.95∗27+10.30∗9+22.17∗18
100
= 7.17

25. Overall Sector Efficiency
• Summary:
• 1- Estimate Energy Efficiency
• 2- Estimate Product temperature
• 3- Calculate Exergy Efficiency
• 4- Calculate Overall Energy &
Exergy Efficiency by using:
• Energy consumption of each
application

26. Conclusion
• The residential/commercial
sector have great potential for
energy savings, because large
disparities exist between the
overall energy and exergy
efficiencies
• Space heating & Water heating
have more inefficiencies
rather than cooking.

27. Analysis of the
Industrial sector
Case study: Turkey (Utlu 2005)

28. Introduction
• Exergy analysis provides more realistic picture considering the irreversibilities and potential
optimization of the process
• A review on exergy analysis of industrial sector [2013 Renewable and Sustainable Energy Reviews]
• Energy consumption in industrial sectors varies between 30% to 70%
• Slovenia: 30%, Jordan: 31%, Turkey: 35%, South Africa: 44%, China: 70%
• Iran:
• 25% of total energy in 2011
• 34.6% electrical energy in 2011
• Exergy analysis of industrial sector divides to:
• 1. Exergy analysis of industrial sector of different countries
• 2. Exergy analysis of different industries
• 3. Exergy analysis of industrial devices

29. Energy Flow in Turkish industrial sector

30. Exergy analysis of Industrial sector
• First, The most energy consuming units are chosen (e.g. for Turkey: iron–steel, chemical–
petrochemical, petrochemical–feedstock, cement, fertilizer, sugar, non-metal industry, Covers ~95%
of energy usage)
• Energy usage in industrial sector can be devided into four different categories:
• 1.Process Heating : 66%
• 2.Mechanical Process : 15%
• 3.Lightning
• 4.Air Condioning
• Characteristic of some fuels are shown :
5% - 18%
82% - 95%

31. Exergy analysis of Industrial sector
• Heating processes for each industry are grouped into low,
medium, and high temperature categories
• H.L. Brown, B.B. Hamel, B.A. Hedman, Energy Analysis of
108 Industrial Processes. Fairmount press, Lilburn, GA,
1996

32. Energy Analysis of 108 Industrial Processes

33. Example process

34. Exergy analysis of Industrial sector

35. Energy Annual Report

36. Hidrocarburi Annual Report

37. Summary
• Energy, Exergy & Entropy analysis are applicable to systems which
contain them
• Energy & Exergy analysis procedure of Residential/Commercial
sector was introduced
• Energy & Exergy analysis procedure of Industrial sector was
introduced
• Some Iranian data source were introduced: Hidrocarburi, Energy

38. Thank you!