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Gas turbine brayton cycle thermodynamic mass flow rate of air

  • Thread starter joesall
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Homework Statement



a gas turbine is designed to produce 3000hp when using air at a maximum inlet temperature of 650k and assuming a heat loss of 70 kj/s. if the exhaust temperature is desired to be no greater than 200 degrees celsius, determine the mass flow rate of air required.

Homework Equations


in the textbook the only things i can find are this formula
Qadd = mcp(t3-t2)
or Qrej = mcp (t1-t4)

but the problem is that solving with these with Qadd/cp(t3-t2) im not sure if that would be correct using the figures given in this problem because it gives you an exhaust temperature and a max inlet temp.

The Attempt at a Solution



im having trouble coming up with the needed equation to determine the mass flow rate. any infromation would be highly appreciated as to the formula needed to find the mass flow rate.
 

Answers and Replies

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Redbelly98
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Homework Statement



a gas turbine is designed to produce 3000hp when using air at a maximum inlet temperature of 650k and assuming a heat loss of 70 kj/s. if the exhaust temperature is desired to be no greater than 200 degrees celsius, determine the mass flow rate of air required.

Homework Equations


in the textbook the only things i can find are this formula
Qadd = mcp(t3-t2)
or Qrej = mcp (t1-t4)

but the problem is that solving with these with Qadd/cp(t3-t2) im not sure if that would be correct using the figures given in this problem because it gives you an exhaust temperature and a max inlet temp.

The Attempt at a Solution



im having trouble coming up with the needed equation to determine the mass flow rate. any infromation would be highly appreciated as to the formula needed to find the mass flow rate.
Welcome to PF! Say, it's rather weird that they threw in HP along with all the metric units -- plus they used both K and °C -- but so be it.

It would seem that the 1st Law, ΔU=Q-W, should work here. You know what Q and W are for, say, a 1 second time duration.
 

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