文档介绍：Thermal Energy Problem Set #3 – Fall 2002
Time spent on problems:
Problem 1:
Problem 2:
Problem 3:
Problem 4:
Problem 5:
Problem 6:
Thermal Energy Problem Set #3 – Fall 2002
Do all problems. Please use a separate sheet of paper for each problem.
1. A Brayton cycle operates in air with a pressure ratio of 10. ponents are ideal.
The temperature at the inlet to pressor is 400 K and the temperature at the
inlet to the turbine is 2000 K. The ic energy at the inlet and exit of all
components can be neglected. Assume that the working fluid has a constant cp=1000
J/kgK.
a) What is pression work per unit mass?
b) What is the turbine work per unit mass?
c) What is work of the cycle per unit mass?
d) What is the heat input per unit mass?
e) What is the heat rejected per unit mass?
f) Express the overall cycle efficiency as the ratio of two of the above (a-
e).
2. An ideal gas-turbine unit (Brayton cycle) operating on a closed cycle is to deliver
6000 kW and receive heat from a nuclear reactor. Different gases are to be studied.
o o
Let the gas be argon: p1=480 kPa, T1=45 C. The argon enters the turbine at 1100 C
and the cycle should be such as to deliver maximum work for these constraints. At
what rate should the argon circulate?
3. Howell & Buckius