Thermodynamics for Energy Conversion

· Short recapitulation of the fundamentals of engineering thermodynamics: first law, energy balance of closed and open systems, second law, entropy and irreversibility. · Specific thermodynamic properties of fluids: properties of water and steam, properties of ideal gas. · Extended definition of exergy and environment. Chemical exergy. Exergy of fuels. Exergy efficiencies. · Value diagrams. Application for heat exchanging equipment and combustion processes. · Exergy losses of basic processes: fuel conversion, heat transfer, turbines, compressors. · Exergy analysis and optimisation of conventional power stations (boiler/steam cycle): boiler: air preheating, steam conditions, feedwater temperature; steam cycle: selection of working fluid, friction losses in boilers, losses in condensor and piping, feedwater pump, extraction feed water heating. · Gas turbine processes, losses and optimization: closed cycle GT process: pressure ratio, turbine inlet temperature, cycle configuration (intercooling, recuperation, reheat); open cycle GT process: cycle configuration, value diagram; combined cycle systems: exergy losses HRSG, multiple pressure steam cycles, supplementary firing; · Combined heat and power production (CHP): thermodynamic principle of CHP, evaluation criteria, applications, power to heat matrix. · Fuel cells: calculation of reversible power and reversible cell voltage, effect of irreversibilities on cell performance, Nernst equation and some characteristics of SPFC (PEMFC), MCFC and SOFC, exergy losses in fuel cell systems. · Refrigeration cycles and heat pumps: properties of working fluids, processes with mixtures, absorption processes, water/lithium bromide systems, ammonia/water systems.

At the end of the module the students are able to evaluate the thermodynamic performance of various conversion processes and systems by applying the exergy concept and to identify ways to reduce overall exergy losses of frequently applied processes and systems.

Basic knowledge of fundamental thermodynamics (first and second law, energy balaces); profund knowledge of mathematical notation, differential equations

90 min lecture including discussion on the current topic per week. Students are encouraged to take part in the discussion and to question the arguments given by the lecturer. Autonomous preparing at home is needed to fully understand the learning matter. 45 min tutorial is held to improve unterstanding of calculations and concepts of the lectures. The students are strongly encouraged to study the exercises in advance to the tutorial. Solutions of the exercises are provided one week after the actual tutorial.

Powerpoint presentations, flip board drawings, additional videos/ pictures/ graphs provided via internet

Handouts, Literature recommendations

The final exam consists of a theoretical part with short questions (60 min.) and a second part with calculations (60 min.). For the theoretical part no further help is allowed. For the calculation part students can use a calculator (non progammable). The theoretical part contains 60 % and the calculation part 40 % of the total points. To pass the exam one must achieve at least 50 % of the total points. The theoretical questions are related to the lecture topics and material, whereas the calculation part is based on the tutorial exercises. Short questions and calculations cannot be passed separately. In the written exam, the student should demonstrate that they are able to apply the main thermodynamic methods listed in the learning outcomes and do the required calculations under time pressure. The exam also contains theoretical questions related to the methods and applications of exergy analysis on energy conversion systems, through which the students prove that they have understood the basic concepts taught during the lectures.