QUESTIONS

Brayton cycle

  • • • • Gas power Uses Auxiliary power generation Stand-alone power generation Naval propulsion Jet engine

Brayton cycle

    1 →2 Isentropic compression 2 →3 steady pressure heat addition 3 →4 4 →1 isentropic expansion steady pressure heat rejection

Brayton cycle

   • •    Working fluid – air Ideal gas High AFR – air as working fluid Complete combustion Temperature limits Thermal reservoirs Open or closed model Steady pressure heat exchange

Brayton cycle

     Work in & work out Heat in & heat out Thermal efficiency Pressure ratio Back work ratio

Brayton cycle

  Variable specific heat – isentropic processes of ideal gas Constant specific heats - k

Cycles

   Otto – r Diesel – r & r c Brayton -r p

Example

  The rate of heat addition to an air standard Brayton cycle is 3.4X10

minimum and maximum cycle temperatures are 520 o R and 3000 9 Btu/hr. The pressure ratio is 14; the o R respectively.

Find the thermal efficiency, mass flow rate, and net power.