BME Depeartment of Energy Engineering Heat Engines and Boilers

Questions on Turbines topic • Describe Carnot cycle. Show processes in T-S chart.

How can be calculated cycle efficiency?

• Describe Rankine-Clausius cycle. Show processes in T-S chart, and connection with real equipments taking place in the process. How can be calculated cycle efficiency?

• Describe Joule-Brayton cycle. Show processes in T-S chart, and connection with real equipments taking place in the process. How can be calculated air standard cycle efficiency?

• Describe methods which are used for increase Rankine cycle efficiency.

• How can be determined optimal pressure ratio for air-standard Joule-Brayton cycle at given maximal fire-chamber outlet temperature.

• Define isentropic efficiency of real compression and expansion process. How can be calculated driving power of compressor and useful power of a turbine section.

• What are differences in between theoretical air-standard and real Joule-Brayton cycle. Show real process flow in T-S chart.

• Describe air-intercooling and fluegas reheat amendment solutions in case of Joule-Brayton cycle. What are advantages and disadvantages of these solutions. What effects they have on efficiency variation?

• Describe principals of combined (Gasturbine – Steamturbine) energy generation. Show process in T-S chart. What are advantages of this combination? How can be calculated efficiency of energy generation?

• Describe advantages and disadvantages of additional firing after gasturbine. How can be calculated efficiency of energy generation in this case?

• Describe principals of Cheng-cycle. Draw operational connection figure. What are advantages and disadvantages of this cycle?

• Describe energy transformation in nozzles. How can be calculated outlet velocity and mass flow rate at certain pressure drop, in case of isentropic expansion.

• Describe velocity and mass flow variation at a certain convergent nozzle in case of different pressure ratio.

• Describe velocity and mass flow variation at a certain convergent-divergent (Laval) nozzle in case of different pressure ratio.

BME Depeartment of Energy Engineering Heat Engines and Boilers • Describe turbine stage construction and connection with velocity triangles.

How can be calculated specific power from data can be gained from velocity triangles?

• Define reaction degree. Draw a typical impulse and reaction (r = 0,5) stage blade cross sections together with belonging velocity triangles.

• Describe turbine stage construction of a Curtiss stage and belonging velocity triangles. How can be calculated specific power from data can be gained from velocity triangles?

• How can be define efficiencies of fixed blade, moving blade and total stage. Which is the connection with isentropic (adiabatic) efficiency. How can be calculated specific and actual power of the turbine stage. Show real process of a stage in H-S chart.

• Describe design principals of a three sectional (High-, medium- and low pressure) steam turbine design. Which parameter determine mainly blade length variation?

• Define reaction degree of a compressor stage. How can be calculated specific, actual power and efficiency of the compressor stage?

• Describe principals and draw functional figure of a gasturbine combustion chamber design.

• Describe gasturbine blade cooling solution possibilities. Why turbine blades needs to be cooled? What are advantages and disadvantages of different cooling solutions?

• Describe principals and draw functional figure of an aviation three shaft turbofan gasturbine design.

Calculations Basic equations and solved problems in the lecture note has to be studied.