Dr.-Ing. Andreas Schäfer

Transcription

1 Eurpean Summer Schl 2014 Infrmatin abut Gaining Primary Energy and Cnversin Technlgies Physical Fundamentals f Energy Cnversin Dr.-Ing. Andreas Schäfer Institute f Pwer Systems and Pwer Ecnmics RWTH Aachen University 1

2 Cntent Intrductin Energy What is it and hw d we use it? Energy Cnversin Principles, Applicatin and Limits Use f Energy in the EU Eurpean Summer Schl

3 Intrductin Energy essential fr humanity Demand fr energy rapidly increasing within the last century New frms f energy are being utilized Sme usable energy surces are limited Awareness f energy efficiency needed Aim f this sessin: Insight in physical fundamentals f energy and its frms Differences between energy and pwer Basic knwledge n energy cnversin prcesses Pint ut limits in cnversin prcesses Eurpean Summer Schl

4 Wrld Energy Cnsumptin per Capita by Cuntry in 2010 Eurpean Summer Schl

5 Cntent Intrductin Energy What is it and hw d we use it? Energy Cnversin Principles, Applicatin and Limits Use f Energy in the EU Eurpean Summer Schl

6 Energy Energy is a fundamental physical quantity Energy E is the capacity f a physical system t perfrm wrk W Perfrming wrk leads t change in energy = Physical unit f energy and wrk typically is Jule [J] r Newtnmeter [Nm] Other units in use fr energy are kilcalries [kcal] kilwatt hurs [kwh], il equivalent [e] Eurpean Summer Schl

7 What is a Jule? One Jule crrespnds t the energy neccessary t lift a bar f chclate (102g) by 1m height heat 1g f water by 0,239 C prvide the pwer f 1 Watt fr 1 secnd 1J = 1Ws = 1Nm = 0,239 cal = 2,388x10-8 OE Energy usually given in higher dimensins such as Kiljule (kj) = 1,000 Jule Megajule (MJ) = 1,000,000 Jule Gigajule (GJ) = 10 9 Jule Terajule (TJ) = Jule Petajule (PJ) = Jule Eurpean Summer Schl

8 Typical rders f magnitude fr Energy 6000 J - Electricity cnsumptin f 100W light bulb in 1 min J Energy cntent f standard AA battery 6-7x10 6 J Basal metablic rate f average human per day J - energy frm the cmbustin f 1 cubic meter f natural gas 2x10 9 J - Energy cntent f car with 61 liter gasline tank 31.5x10 15 J Yearly electricity utput f 1,000 MW pwer plant (large plant) 7.344x10 19 J Energy cnsumptin EU27 in x10 20 J Wrld s Energy cnsumptin in J Estimated wrld s fssil fuel reserves August 22nd and 23rd,

9 Frms f Energy Mechanical Energy Kinetic mtin f a bdy Wind turbines use wind s kinetic energy Ptential stred in a system due t its psitin, e.g. Water stred at upper basin f strage plant Rllercaster (with cnversin int kinetic energy) Eurpean Summer Schl

10 Frms f Energy Internal Energy Thermal Micrscpic mvements inside the cnsidered system à Leads t rise / decrease in temperature Chemical Cntained in mlecules / chemical bnds à Ptential t underg chemical reactins (fd, batteries, fuel, ) Nuclear Binding nuclens t frm the atmic nucleus Eurpean Summer Schl

11 Frms f Energy Radiant Radi waves, (sun-)light, X-Rays Directly used in PV cells r X-Ray machines Electric Energy frm electric fields / mving electric lads Can be bserved in lightning flash Hardly any direct applicatin, but imprtant rle fr transprt and cnversin Gravitatinal Energy required t pull material apart Nt utilized yet Eurpean Summer Schl

12 Car1 Energy vs. Pwer: Time matters! Energy ¹ Pwer Same amunt f energy can be utilized within different span f time à The shrter the time, the higher the pwer Car2 = à Same energy cnsumed < = > = à Car1 has higher pwer Pwer = is the rate f ding wrk in time with the unit Watt = Eurpean Summer Schl

13 Cntent Intrductin Energy What is it and hw d we use it? Energy Cnversin Principles, Applicatin and Limits Use f Energy in the EU Eurpean Summer Schl

14 Basic laws fr energy and cnversin Energy can neither be created r destryed à Cnservatin f energy (amunt f all energy is cnstant, 1st law f thermdynamics) In an islated system, the ttal energy remains the same = = = Energy can be stred r cnverted int ther frms f energy Eurpean Summer Schl

15 Simple energy cnversin in car Basically, chemical energy frm fuel is cnverted int kinetic energy (mving the car) and thermal energy (heat f the engine, frictin f tires and drag, exhaust gases) = + Driving uphill, ptential energy increases additinally = + + = Eurpean Summer Schl

16 frm Typical types f energy cnversin Mechanical Thermal Chemical Electrical Radiant Nuclear Thermal Chemical Electrical t Steam Turbine Electrical Engine Heat Exchanger Gas heater Electric stve Blast furnace Accumulatr Mechanical Gear bx Brakes Generatr Particle acceleratr Gethermal unit Fuel Cell / Batteries Fire Light bulb Radiant Slar thermal unit Pht synthesis PV cell Nuclear Nuclear bmb Nuclear reactr Gamma rays Breeder reactr Eurpean Summer Schl

17 Energy cnversin Energy cannt be destryed ¹ all energy is utilized after cnversin Mst cnversin prcesses include lsses in e.g. frm f unusable heat The higher the share f the desired frm energy after cnversin, the higher the cnversin s efficiency = 1 E input E utput E lsses Eurpean Summer Schl

18 Heat engine as typical mechanism f energy cnversin Heat engine is a mechanism cnverting heat int mechanical energy Wrking substance (e.g. water r steam) is brught frm higher temperature t lwer temperature level Many cnversins based n principle f heat engine, such as Cmbustin engines Steam and gas turbines Stirling engines Eurpean Summer Schl

19 Wrking principle f a heat engine Efficiency f ideal heat engine limited by Carnt s therem: = 1 100% with T cld and T Ht temperatures f the reservirs Increase f temperature in ht reservir r decrease cld fr higher efficiency Carnt efficiency theretical value due t additinal lsses Real engines with lwer values Eurpean Summer Schl

20 Applicatin f heat engines Steam turbine is heat engine Typical temperatures: T Ht = 900K (626 C) T Cld = 300K (26 C, envirnment) Max. efficiency = 1 = 66% Real value lwer 50% Reasns in additinal applicatins such as pumps Exhaust gas with higher temperature Operatin in partial lad Eurpean Summer Schl

21 Implicatins frm Carnt therem = 1 100% Outside temperature usually given Increase f max. temperature and use f exhaust temperatures in prcesses desired T Cld > 0K à Heat cannt fully be cnverted int ther frms f energy (2. law f thermdynamics) Free heat energy f lwer value Amunt f unusable heat increases à Efficient energy cnversin prcesses avid generatin f much unusable heat Eurpean Summer Schl

22 Cnversin in wind turbines Kinetic energy f wind is cnverted int electrical energy Efficiency f cnversin prcess is limited by Betz s law Limit f 59.3% f wind s kinetic energy cannt be exceeded in wind turbine Wind cannt be slwed dwn t 0 fr keep flwing à nt all f the kinetic energy can be extracted and cnverted Real wind turbines reach up 45% efficiency Eurpean Summer Schl

23 Cntent Intrductin Energy What is it and hw d we use it? Energy Cnversin Principles, Applicatin and Limits Use f Energy in the EU Summary Eurpean Summer Schl

24 Energy Flws in the EU-27 in 2010 August 22nd and 23rd, 2013 Surce: 24 EEA

25 Thank yu fr yur attentin Dr.-Ing. Andreas Schäfer Institute f Pwer Systems and Pwer Ecnmics RWTH Aachen University ( +49 (0) * andreas.schaefer@iaew.rwth-aachen.de : Eurpean Summer Schl