Question

Air at 277 oC and 1000 kPa enters a turbine operating at steady state with a mass flow rate of 70 kg/hr. It exits the turbine at 27 oC and 700 kPa. During this process heat is added from the surroundings at 77 oC to the turbine at a rate of 1000 kJ/hr. Using variable specific heats, determine whether this claim is correct. Justify your answer.

Answer #1

An adiabatic compressor operates on air in a steady state
process. The air enters the compressor at 25 oC and 150 kPa and
exits at 250 oC and 500 kPa. Assuming constant specific heats for
air at 300K, calculate the isentropic efficiency for this
compressor.

NO INTERPOLATION REQUIRED
Air enters an adiabatic turbine at 1000 kPa and 1625 degrees C
(state 1) with a mass flow rate of 5 kg/s and leaves at 100 kPa the
isentropic efficiency of the turbine is 85%. Neglecting the kinetic
energy change of the steam, and considering variable specific
heats, determine:
a. the isentropic power of the turbine
Isentropic power in kW
b. the temperature at the turbine exit
temperature at exit in degrees C
c. the actual power...

An air turbine with inlet conditions of 500 kPa, 327 C operates
in steady flow and has an actual power output of 70 kW. The
discharge pressure is 100 kPa and the turbine has an efficiency of
0.8 at these operating conditions. Consider specific heats
constant.
a) Calculate the actual mass flow rate at the turbine exit.
b) Calculate the actual turbine exit temperature.
c) Show the actual and ideal processes on a T-s and P-v
diagram.

Water at p1 = 20 bar, T1
= 400oC enters a turbine operating at steady state and
exits at p2 = 1.5 bar, T2 =
230oC. The water mass flow rate is 4000 kg/hour. Stray
heat transfer and kinetic and potential energy effects are
negligible.
Determine the power produced by the turbine, in kW, and the rate of
entropy production in the turbine, in kW/K.

An adiabatic gas turbine uses air to produce work. Air expands
adiabatically from 600 kPa and 287 C to 90 kPa and 67 C. Take
specific heats at room temperature (300 K). a) Find the isentropic
efficiency of the turbine. b) Find the work produced by the turbine
for a mass flow rate of 2.5 kg/s. c) If the mass flow rate of air
is again 2.5 kg/s, find the entropy generation under steady
conditions.

Air enters a counterflow heat exchanger operating at steady
state at 22°C, 0.1 MPa and exits at 7°C. Refrigerant 134a enters at
0.2 MPa, a quality of 0.21, and a mass flow rate of 30 kg/h.
Refrigerant exits at 0°C. There is no significant change in
pressure for either stream. (a) For the Refrigerant 134a stream,
determine the rate of heat transfer, in kJ/h (b) For the
refrigerant stream evaluate the change in flow exergy rate, in
kJ/h. (c) For...

Water vapor at 6 MPa, 500°C enters a turbine operating at steady
state and expands to 20 kPa. The mass flow rate is 3 kg/s, and the
power developed is 2626 kW. Stray heat transfer and kinetic and
potential energy effects are negligible. Determine: (a) the
isentropic turbine efficiency and (b) the rate of entropy
production within the turbine, in kW/K.

13) A turbine, operating under steady-flow
conditions, receives 5000 kg of steam per hour. The steam enters
the turbine at a velocity of 3000 m/min, an elevation of 5 m and a
specific enthalpy of 2787 kJ/kg. It leaves the turbine at a
velocity of 6000 m/min, an elevation of 1 m and a specific enthalpy
of 2259 kJ/kg. Heat losses from the turbine to the surroundings
amount to 16736 kJ/h. Determine the power output of the
turbine.
14) 12 kg...

Steam at 6 MPA, 600°C, enters a well-insulated turbine operating
at steady state and exits at 0.1 bar. The isentropic efficiency of
the turbine is 94.7%. Assuming the kinetic and potential energy
effects to be negligible, determine:
(a) Work output, in kJ/kg,
(b) The temperature at the exit of the turbine, in °C, and
(c) The rate of entropy production within the turbine, in kJ/K
per kg of steam flowing through the turbine.
(All steps required – Given/Find/Schematic/Engineering
Model/Analysis)
THANK...

Air at 100 kPa and 10°C enters a compressor and is brought to
1000 kPa and 50°C. The constant pressure heat capacity of air is
1.01 kJ/kg K. If 15 kg/min of air are to be compressed, determine
the power require- ment of the compressor. State your assumptions.
(12.625 kW)

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 9 minutes ago

asked 12 minutes ago

asked 13 minutes ago

asked 18 minutes ago

asked 20 minutes ago

asked 26 minutes ago

asked 31 minutes ago

asked 31 minutes ago

asked 36 minutes ago

asked 36 minutes ago

asked 40 minutes ago

asked 1 hour ago