& Review of Thermodynamics Class # 1

Apresentação em tema: "& Review of Thermodynamics Class # 1"— Transcrição da apresentação:

1 & Review of Thermodynamics Class # 1
Gestão de Energia: 2013/2014 Introduction & Review of Thermodynamics Class # 1 Prof. Tânia Sousa

2 Docentes Tânia Sousa Carla Silva Carlos Silva André Pina
Carla Silva Carlos Silva André Pina

3 Avaliação Exame (50%) com nota mínima 9.5 val.
Avaliação Contínua (50%) Trabalhos feitos por grupos de 2/3 alunos Os trabalhos começam nas aulas e são para terminar em casa A avaliação é feita nas aulas e com os trabalhos Trazer um portátil por grupo para as aulas práticas

4 Objectivo Compreender e modelar os fluxos energéticos à escala do país, em sistemas industriais, em edifícios ou equipamentos complexos. Definir acções que permitam racionalizar o uso da energia, quantificando os benefícios económicos e ambientais destas acções.

5 Gestão de Energia: Conteúdo
Semana Teóricas Práticas Apresentação. Revisões Termodinâmica Balanço Energético Português Exercícios Energia Primária Final e e Útil. Diagramas de Sankey Transições Energéticas. Análise da Eficiência de Sistemas Energéticos Trabalho I (B.E.N) Modelos analíticos para a análise energética de sistemas: diagramas de blocos Trabalho II (Sankey) Eficiência Energética na Indústria. Regulamento da eficiência energética na indústria (SGCIE). Eficiência Energética nos edifícios. Regulamentos de eficiência energética nos edifícios. Trabalho III Modelos Input-Output Energia e Economia Métodos de contabilização da electricidade primária. Trabalho IV (Input-Output) FÉRIAS FERIADO Análise Ciclo de Vida Eficiência energética nos Transportes. Regulamento da eficiência energética nos Transportes Auditorias Energéticas Trabalho V (Tranportes) Modelação Oferta e Procura de Energia Visita a um Laboratório Tagus Park Revisões. 4ª feira à tarde 4ª feira manhã e à tarde

6 Course Contents Thermodynamics
Energy and Entropy Balances for Closed & Open Systems Thermodynamic Cycles: power cycle, heat pump & refrigerator cycle 1st Pratical Class (exercises) Bibliography “Fundamental of Engineering Thermodynamics” Shapiro & Moran

7 Course Contents – T2 The Portuguese Energetic Balance:
Supply, Conversion & Demand Energy Carriers BALANÇO ENERGÉTICO tep Total de Carvão Total de Petróleo Gás Natural (*) Gases o Outros Derivados Total de Eectricidade Calor Resíduos Industriais Renováveis Sem Hídrica TOTAL GERAL 2008 4 = 1 a 3 22= 23 30 = 24 a 29 36 = 31 a 35 37 38 46 = 39 a 45 47= IMPORTAÇÕES 1. PRODUÇÃO DOMÉSTICA 2. 39 800 VARIAÇÃO DE "STOCKS" 3. 5 960 - 837 97 193 SAÍDAS 4. 24 949 17 634 CONSUMO DE ENERGIA PRIMÁRIA 5. PARA NOVAS FORMAS DE ENERGIA 6. 1 120 CONSUMO DO SECTOR ENERGÉTICO 7. 56 103 3 CONSUMO COMO MATÉRIA PRIMA DISPONÍVEL PARA CONSUMO FINAL 8. 81 170 38 680 ACERTOS 9. 9 851 12 279 CONSUMO FINAL 10. 71 319 AGRICULTURA E PESCAS 10.1 3 359 87 218 2 366 21 INDÚSTRIAS EXTRACTIVAS 10.2 66 103 8 444 49 882 30 844 4 INDÚSTRIAS TRANSFORMADORAS 10.3 CONSTRUÇÃO E OBRAS PÚBLICAS 10.4 5 063 50 490 TRANSPORTES 10.5 6 659 46 677 3 452 SECTOR DOMÉSTICO 10.6 SERVIÇOS 10.7 14 211 6 579

8 Course Contents – T2 2nd Pratical Class & 1st assignment
Each group analyses the PEB for a specific year and compares it with 2012 (bring the computer) Learning Outcomes: Be able to retrieve information from the Energetic Balance of a country/region Compute electricity production efficiencies and other 1st law efficiencies for the country level Bibliography: Chap. 2 “Balanço Energético Nacional - Metodologia de Elaboração, Evolução da Estrutura e do Consumo Energético Primário”, Ramos, A. Chap. 2 “Energy Economics”, Bhattacharyya.

9 Course Contents - T3 From Primary Energy to Energy Services at different scales IAASA - Global Energy Assessment 2012

10 Course Contents - T3 World and national patterns of energy use
Energy Transitions Energy Transition Energy Transition biomass to coal coal to oil Grubler, A. “Energy Transitions”

11 Course Contents - T3 Sankey diagrams for different scales
1st and 2nd Law Efficiencies

12 Course Contents – T3 2nd Pratical Class & 1st assignment
Each group draws the Sankey diagram using e-Sankey for the PEB for a specific year for Portugal Learning outcomes: Understand concepts of primary, final & useful energy Historical perspective on world energy use & transitions Use Sankey diagrams to analyse energy systems Understand 1st and 2nd law efficiencies Bibliography: Cap. 2 da sebenta “Gestão de Energia”, Águas, M. Chapter 1 & 16 GEA, IAASA Cullen and Alwood “The efficient use of energy: Tracing the global flow of energy”, Energy Policy 2010.

13 Course Contents – T4 Block Diagrams Energy Analysis
3th Practical Class Exercises Learning Outcomes Compute the energy intensity of a product or service, i.e., the total energy required to produce it Compute the impact of efficiency measures on the specific energy consumption Bibliography: Cap. 5 da sebenta “Gestão de Energia”, Águas, M.

14 Course Contents – T5 Energy use in industry
SGCIE: Energy efficiency in industry 4th Practical Class & 3rd assignment Each group chooses a case study (e.g. the Secil), finds the correct data and describes the production process and computes the specific consumption

15 Course Contents – T5 Learning Outcomes Bibliography:
Apply & understand the SGCIE legislation Bibliography: DL n.º 71/2008; Despachos nº 17449/2008 & 17313/2008 Chap. 6 “Energy Efficiency and the Demand for Energy Services” Danny Harvey

16 Course Contents – T6 Energy use in Buildings
Factors controlling energy use in buildings Techniques to reduce energy use:

17 Course Contents – T6 RCCTE & RSECE: Energy efficiency in buildings
5th Practical Class Exercises Learning Outcomes Learn about strategies to reduce energy use in buildings and their impact Apply & understand the RCCTE & RSECE Bibliography: Chap. 4 “Energy Efficiency and the Demand for Energy Services” Danny Harvey Decreto-lei n.º 118/2013

18 Course Contents - T7 IO Analysis at the Macroeconomic scale
Computation of Direct and Indirect Effects of changes in Demand 6th Pratical Class & 4th assignment Each group computes energy demand scenarios for a country for 2 & 5 & 10 years based on changes in the economic structure & compares with reality Application of this methodology to Block Diagrams Analysis Bibliography: Chap. 5 “Ecological Economics”, Common & Stagl.

19 Course Contents – T8 Methods to compute primary energy for renewable electricity EROI

20 Course Contents – T8 Learning Outcomes Bibliography
Critically evaluate statistics and political goals on the weight of renewables on primary energy mixes at the country level. Understand & apply the concept of EROI Bibliography Chapter. 14 & 15 from “Energy and the Wealth of Nations”,Hall, C. & Klitgaard, K.. 7th Practical Class Exercises

21 Course Contents – T8 Energy & Economic Growth & Environment

22 Course Contents – T8 Learning Outcomes Bibliography:
Identify the interactions between energy use, economic growth and environmental quality Bibliography: Chap. 2 & 6 “Energy at the Crossroads” Smil, V.

23 Course Contents – T9 Life Cycle Assessment 8th Practical Class
Exercises Bibliography: Bioethanol Life Cycle CO2 Bioethanol DDG

24 Course Contents – T10 Energy use in Transports

25 Course Contents – T10 Legislation 9th Practical Class
Exercises Learning Outcomes Learn about factors that influence energy use in transports and strategies & technologies that reduce the energy use in and their environmental impact Apply & understand the legislation on transports Bibliography: Chap. 5 “Energy Efficiency and the Demand for Energy Services” Danny Harvey

26 Course Contents – T11 Energy Audits 10th Practical Class Measurements
Mass and Energy Balances Equipments 10th Practical Class Visita de Estudo (no Tagus Park)

27 Course Contents – T12 Tools to Model the Supply and Demand of Energy
11th Practical Class Exercises Learning Outcomes Learn about the energy modeling softwares & their usefulness

28 Energy Balance in Closed Systems
Energy Change = Heat + Work Energy change in the system Flows at the boundaries work 1st Law: Energy Conservation U, Ec and Ep Energy transfer by Heat Energy transfer by Work Sign of heat and work fluxes Steady state vs. Transient Nos três acetatos seguintes coloquei bonecos para poderes explicar melhor as leis da ternodinâmica heat

29 Energy Balance in Closed Systems
Choosing the boundaries Flows, Thermodynamic System, Steady vs. Transient state – flows at the boundaries? Nos três acetatos seguintes coloquei bonecos para poderes explicar melhor as leis da ternodinâmica

30 Energy Balance in Closed Systems
Choosing the boundaries Flows, Thermodynamic System, Steady vs. Transient state Nos três acetatos seguintes coloquei bonecos para poderes explicar melhor as leis da ternodinâmica

31 Energy Balance in Closed Systems
Exercise: Nos três acetatos seguintes coloquei bonecos para poderes explicar melhor as leis da ternodinâmica

32 Energy Balance in Closed Systems
Thermodynamic Cycles 1st Law efficiencies Power Cycle Heat Pump Refrigerator Power Cycle Refrigerator & Heat Pump Cycles Nos três acetatos seguintes coloquei bonecos para poderes explicar melhor as leis da ternodinâmica

33 Energy Balance in Closed Systems
Exercise (Homework) If P is constant then If PV is constant then Nos três acetatos seguintes coloquei bonecos para poderes explicar melhor as leis da ternodinâmica

34 Energy Balance in Closed Systems
Exercise (Homework) Exercise: Why is it possible that ? How much does the electricity of your fridge costs in a month? Nos três acetatos seguintes coloquei bonecos para poderes explicar melhor as leis da ternodinâmica

35 Energy Balance in Open Systems
Mass Change =  Mass Flows Energy Change = Heat + Work + Energy in Mass Flow Nos três acetatos seguintes coloquei bonecos para poderes explicar melhor as leis da ternodinâmica Enthalpy of component j Flows at the boundaries

36 Energy Balance in Open Systems
Exercises 1º Write the energy balance eq. 2º Identify energy flows 3º Simplify the eq. For incompressible liquids at constant pressure: Nos três acetatos seguintes coloquei bonecos para poderes explicar melhor as leis da ternodinâmica

37 Energy Balance in Open Systems
Turbines: Produce work as a result of gas or liquid passing through a set of blades attached to a shaft free to rotate Electricity from Epot of the water Electricity from Ekin of the wind Wmec from Ekin of the wind Nos três acetatos seguintes coloquei bonecos para poderes explicar melhor as leis da ternodinâmica Hydraulic Turbine Wind Mill Wind Turbine

38 Energy Balance in Open Systems
Turbines: Produce work as a result of gas or liquid passing through a set of blades attached to a shaft free to rotate Electricity from Epot of the water Electricity from Ekin of the wind Wmec from Ekin of the wind Nos três acetatos seguintes coloquei bonecos para poderes explicar melhor as leis da ternodinâmica Hydraulic Turbine Wind Mill Wind Turbine

39 Energy Balance in Open Systems
Exercises Write the energy balance eq. Identify energy flows Simplify the eq. What is the energy conversion taking place? Castelo de Bode dam 3 turbines medium water fall 80 m Installed power: 159 MW Medium annual electricity production: 390 GWh Nos três acetatos seguintes coloquei bonecos para poderes explicar melhor as leis da ternodinâmica

40 Energy Balance in Open Systems
Exercises Write the energy balance eq. Identify energy flows Simplify the eq. Potential energy is converted into electricity and kinetical energy Castelo de Bode dam 3 turbines medium water fall 80 m Installed power: 159 MW Medium annual electricity production: 390 GWh Nos três acetatos seguintes coloquei bonecos para poderes explicar melhor as leis da ternodinâmica

41 Energy Balance in Open Systems
Compressors (gas) & Pumps (liquids): Used in aircraft engines, water pumping, natural gas transport, etc Increase the pressure of a gas (compressor) or move fluids or slurries (pumps) using work Reciprocating Compressor Increase in pressure of gas obtainned from decreasing volume (obtainned with work) Nos três acetatos seguintes coloquei bonecos para poderes explicar melhor as leis da ternodinâmica Pump water using work Pump water using human work Treadle Pump Pumps

42 Energy Balance in Open Systems
Compressors (gas) & Pumps (liquids): Used in aircraft engines, water pumping, natural gas transport, etc Increase the pressure of a gas (compressor) or move fluids or slurries (pumps) using work Reciprocating Compressor Increase in pressure of gas obtainned from decreasing volume (obtainned with work) Nos três acetatos seguintes coloquei bonecos para poderes explicar melhor as leis da ternodinâmica Pump water using work Pump water using human work Treadle Pump Pumps

43 Energy Balance in Open Systems
Exercises 1º Write the energy balance eq. 2º Identify energy flows 3º Simplify the eq. Ideal gas model: The need to cool after compression Underground storing of natural gas in Carriço Storing Pressure: 180 bar Storing capacity: GWh Nos três acetatos seguintes coloquei bonecos para poderes explicar melhor as leis da ternodinâmica

44 Energy Balance in Open Systems
Heat Exchangers: Used in power plants, air conditioners, fridges, liquefication of natural gas, etc Transfer energy between fluids at different temperatures Nos três acetatos seguintes coloquei bonecos para poderes explicar melhor as leis da ternodinâmica Direct Contact Heat Exchanger Counter-flow Heat exchanger Direct Flow Heat Exchanger

45 Energy Balance in Open Systems
Heat Exchangers: Used in power plants, air conditioners, fridges, liquefication of natural gas, etc Transfer energy between fluids at different temperatures Nos três acetatos seguintes coloquei bonecos para poderes explicar melhor as leis da ternodinâmica Direct Contact Heat Exchanger Counter-flow Heat exchanger Direct Flow Heat Exchanger

46 Energy Balance in Open Systems
Exercises (homework) 1º Write the energy balance eq. 2º Identify energy flows 3º Simplify the eq. Discuss boundaries Liquefaction of natural gas T=-162ºC Decrease in volume: 1/600 Nos três acetatos seguintes coloquei bonecos para poderes explicar melhor as leis da ternodinâmica

47 Power cycle revisited Coal power plant: Power Cycle Refrigerator
Nos três acetatos seguintes coloquei bonecos para poderes explicar melhor as leis da ternodinâmica Power Cycle Refrigerator

48 The state variable: Entropy
Entropy is the state variable that gives unidirectionality to time in physical processes ocurring in isolated & adiabatic systems. Hot coffee in a cold room gets colder and not hotter Radiating energy is received by the Earth from the sun and by outer space from the earth and not the other way around. If the valve of the tyre is opened, air gets out and not in

49 Entropy Balance in Closed Systems
Entropy Change = Entropy transfer in the form of heat + entropy production Not relevant for entropy balance It is not a flow at the boundary Flows at the boundaries Entropy change in the system work Meaning of  2st Law: >0 In adiabatic systems… Entropy transfer by Heat & sign Steady state vs. Transient Nos três acetatos seguintes coloquei bonecos para poderes explicar melhor as leis da ternodinâmica heat

50 Entropy Balance in Closed Systems
2nd Law: In an adiabatic system the entropy must not decrease Suppose the system is adiabatic and that T2>T1 2nd Law: the arrow of time Nos três acetatos seguintes coloquei bonecos para poderes explicar melhor as leis da ternodinâmica T2 T1 T2 T1