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Gestão de Energia : 2013/14. Class # 4 Energy Analysis: Block diagrams Prof. Tânia Sousa taniasousa@ist.utl.pt. Energy Analysis. Definition: the process of determining the energy intensity of a product or service, i.e., the energy required directly and indirectly to produce it
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Gestão de Energia: 2013/14 Class # 4 Energy Analysis: Block diagrams Prof. Tânia Sousa taniasousa@ist.utl.pt
Energy Analysis • Definition: the process of determining the energy intensity of a product or service, i.e., the energy required directly and indirectly to produce it • The energy used indirectly might be more important that the energy used directly Auto-industryassemblyline Electricity Paint
Energy Analysis • Questionswe can answerwithanEnergyAnalysis: • Whatistheenergyneeded to produce 1 kg ofsteel? • Howmuchenergyissavedbyrecyclingwasteglassproducedinside a glassfactoryback to thefurnace? • Whatistheembodiedenergyoffoodconsumed in Swedenandthe UK? (1 MJ = 0.024 kgoe)
Energy Analysis • DifficultiesassociatedwiththeEnergyAnalysisframework: • Choosingthesystemboundary • Mergeseveralkindsofenergy • Ex: theproductionoffueloilfrom crude oilhas a muchhigherefficiencythantheproductionofelectricityfromcoal • EnergyCredit for by-products • Ex: by-productsfromtheiron & steelindustry are usedbythecementindustry
EnergyAnalysis: Basic Operations • UnitaryProductionOperation • Conventions: • The use ofblockletters for Operations • The use ofnumbers for Inputs/Outputs Energy consumption EA Materials lnput Production m1 Operation A m3 m2 Residues mR
Energy Analysis: Specific Consumption of Operation & Inputs • SpecificConsumptionofOperation A: CEA • SpecificConsumptionof Material 1: CE1
Energy Analysis: Mass Factors • Residueformation factor • Massproportion
EnergyAnalysis: SpecificConsumptionofProduction • Whatistheenergyspecificconsumptionof m3?
EnergyAnalysis: SpecificConsumptionofProduction • Whatistheenergyspecificconsumptionofm3? • Writeit as
Energy Analysis: Specific Consumption of Production • Whatistheenergyspecificconsumptionof m3? • Writeit as DirectEnergy Use IndirectEnergy Use
EnergyAnalysis: SpecificConsumptionofProduction • Whatistheenergyspecificconsumptionofm3? • Whatisthespecificconsumptionofresidues?
Energy Analysis: Specific Consumption of Production • Whatistheenergyspecificconsumptionof m3? • Thespecificconsumptionofresiduesisnull No energyconsumptionisattributed to mR (whichisalsoan output ofoperation A)
EnergyAnalysis: SpecificConsumptionofProduction • Whatistheenergyspecificconsumptionofm3? • Why does a higherresidueformation factor, SA,implies a higherspecificconsumptionoftheuseful output, CE3?
EnergyAnalysis: SequentialProcess • Whatistheenergyspecificconsumption CE4? EC 1 2 3 4 A B C EA EB
EnergyAnalysis: SequentialProcess • Whatistheenergyspecificconsumption CE4? • Writeit as a functionof: EC 1 2 3 4 A B C EA EB
EnergyAnalysis: SequentialProcess • Whatistheenergyspecificconsumption CE4? EC 1 2 3 4 A B C EA EB
EnergyAnalysis: SequentialProcess • Whatistheenergyspecificconsumption CE4 usingthis exterior boundary? 1 2 3 4 A B C EC EA EB
EnergyAnalysis: SequentialProcess • Whatistheenergyspecificconsumption CE4 usingthis exterior boundary? • Homework: Prove thatthisexpressionisequal to 1 2 3 4 A B C EC EA EB
Exercise Consider the production system of floor pavement that has only: a ceramic oven, choice of defective parts and storage. The specific consumption of the furnace is 200 kJ / kg, whereas the specific energy consumption of the choice operation is 5 kJ / kg and the specific energy consumption of storage operation is 20 kJ / kg. The floor raw material involved an energy consumption of 50 kJ / kg in the clay processing operations. The operation of cooking promotes the volatilization of certain components of raw pavement representing 5%. The operation of choice rejects 10% of the output of the furnace and breaks during storage are 1%. Determine the specific consumption of the floor pavement.
Exercise Scheme CEA = 200 kJ/kg; CEB= 5 kJ/kg; CEC= 20 kJ/kg CE1= 50 kJ/kg; SA= 1/0.95; SB= 1/0.9; SC= 1/0.99 EC EA EB 1 2 3 4 Oven Choice Storage
EnergyAnalyis: ConvergentProcess • WhatistheenergyspecificconsumptionCE5? 1 A 2 5 C 4 3 B
EnergyAnalyis: ConvergentProcess • WhatistheenergyspecificconsumptionCE5? 1 A 2 5 C 4 3 B
Exercise A company manufacturing sunflower oil imports 60% of raw material and the remaining 40% is domestically produced. The sunflower imported is transported by sea 1000 km, while the national sunflower is transported by truck 200 km. The operation of oil refining has a specific consumption of 100 kJ/kg. The oil content of sunflower is 10%, meaning that the rejection mass on refining is 90% (in fact thismaterial is used in the manufacture of cattle feed). The specific consumption of transport is 0.025 kJ/kg.km by truck and 0.010 kJ/kg.km by sea. Losses in sunflower transportation are 1% on truck and 0.1% on ship. Determine the specific consumption of refined oil.
Exercise Scheme CEA =10000.01 kJ/kg; CEB =2000.025 kJ/kg; CEC =100 kJ/kg; SA = 1/0.999; SB= 1/0.99; SC= 1/0.1; CE1 = CE3= 0; 1 A: Transportship 2 5 C: Refining 4 3 B: Transporttruck
3 B 2 1 A 4 5 C EnergyAnalyis: DivergentProcess • In a divergentprocessallproductsthat are an output ofthesameoperationhavethesamespecificenergyconsumption • There are otheroptions to giveenergycredit to by-products, e.g., economic.
3 B 2 1 A 4 5 C EnergyAnalyis: DivergentProcess • What are theenergyspecificconsumptionsCE5 & CE3?
3 B 2 1 A 4 5 C EnergyAnalyis: DivergentProcess • What are theenergyspecificconsumptionsCE5 & CE3?
E G 1 D B 4 A 6 2 9 10 11 5 C 7 3 8 12 F Exercise • Compute CE11and CE12
E G 1 D B 4 A 6 2 9 10 11 5 C 7 3 8 12 F Exercise • Compute CE11and CE12
EnergyAnalysis: TreatmentOperation • WhatistheenergyspecificconsumptionCE2? • Energyconsumption in a treatmentoperationisassigned to theoperationthatgeneratestheresidues (A)
EnergyAnalysis: TreatmentOperation • WhatistheenergyspecificconsumptionCE2?
EnergyAnalysis: TreatmentOperation • WhatistheenergyspecificconsumptionCE2? • WhatistheenergyspecificconsumptionCE3?
Energy Analysis: Treatment Operation • What is the energy specific consumption CE2? • What is the energy specific consumption CE3? • The energy specific consumption of the output from the treatment operation is null
Energy consumption E A Materials Production input m m 1 2 Operation A Recycled residues Residues m R Energy consumption m Treatment 3 in treatment operation B E B EnergyAnalysis: Recycling • WhatisthespecificconsumptionofproductionCE2? m4 Recycling operation C
Energy consumption E A Materials Production input m m 1 2 Operation A Recycled residues Residues m R Energy consumption m Treatment 3 in treatment operation B E B EnergyAnalysis: Recycling • WhatisthespecificconsumptionofproductionCE2? • Otherrecyclingschemes: m4 Recycling operation C
Exercise 4 D • Compute CE6 3 1 R C (treat) A 5 2 6 B
Exercise 4 D • Compute CE6 3 1 R C (treat) A 5 2 6 B
EnergyAnalyis: Energy & material inputs • Whatisthemeaningof E1? • E1 isthe total energyused to produce m1 • For consistencypurposeswhatshouldbethemeaningof EA?
EnergyAnalyis: Energy & material inputs • Whatisthemeaningof E1? • E1 isthe total energyused to produce m1 • For consistencypurposeswhatshouldbethemeaningof EA? • EA shouldbethe total energyused to producethatenergyconsumption, i.e., EA shouldbetheprimaryenergyassociatedwiththe final energy input • To mergeseveralkindsoffinal energyfirstconverteachone to primaryenergyandthenmakethe sum
EnergyAnalyis: Energyefficiencymeasures • Whatistheimpactofanenergyefficiencymeasurethatdecreases CEAonCEoutput? B 1 2 3 4 1 2 A A B C EC 3 EA EB 5 EB EA ED 4 D EC 6 C
EnergyAnalyis: Energyefficiencymeasures • Whatistheimpactofanenergyefficiencymeasurethatdecreases CEAonCEoutput? B 1 2 3 4 1 2 A A B C EC 3 5 EA EB EB EA ED 4 D EC 6 C
Exercise A factory produces 2 end products: P1 and P2. These products follow the production process shown in the diagram below, with P1 = 50000 ton/year and P2 = 30000 ton/year. The operation G treats the effluents from E and F. These two (E and F) are the only productive operations that generate waste, and SE = 1.2, SF = 1.3. In operation G, only 20% of the input effluent, exits the process as waste. The values of composition are as follows: f4 = 0.4, f6= 0.5. The table presents the specific consumption of each operation. Consider that for electricity: 0.215 kgep/kWh and for fueloil 0.984 kgep/kg. What is the specific consumption of each product? 13 G 14 3 6 11 12 C 4 7 8 (produção 1) A E 1 5 D 9 10 (produção 2) B F 2
Exercise A factory produces 2 end products: P1 and P2. These products follow the production process shown in the diagram below, with P1 = 50000 ton/year and P2 = 30000 ton/year. The operation G treats the effluents from E and F. These two (E and F) are the only productive operations that generate waste, and SE = 1.2, SF = 1.3. In operation G, only 20% of the input effluent, exits the process as waste. The values of composition are as follows: f4 = 0.4, f6= 0.5. The table presents the specific consumption of each operation. Consider that for electricity: 0.215 kgep/kWh and for fueloil 0.984 kgep/kg. In which product will a measure of energy savings implemented in the operation A reduce more the specific consumption? 13 G 14 3 6 11 12 C 4 7 8 (produção 1) A E 1 5 D 9 10 (produção 2) B F 2
Exercise A factory produces 2 end products: P1 and P2. These products follow the production process shown in the diagram below, with P1 = 50000 ton/year and P2 = 30000 ton/year. The operation G treats the effluents from E and F. These two (E and F) are the only productive operations that generate waste, and SE = 1.2, SF = 1.3. In operation G, only 20% of the input effluent, exits the process as waste. The values of composition are as follows: f4 = 0.4, f6= 0.5. The table presents the specific consumption of each operation. Consider that for electricity: 0.215 kgep/kWh and for fueloil 0.984 kgep/kg. Calculate f13 13 G 14 3 6 11 12 C 4 7 8 (produção 1) A E 1 5 D 9 10 (produção 2) B F 2
Exercise 3800 15200 10000 30000 30000 50000 42400 27600 13 G 14 30000 9000 11 12 41400 30000 C 39000 41400 8 (produção 1) A E 1 D B F 2