A twin cylinder ammonia compressor with volume displacement of 14,726 cm operates at 300 rpm. Condenser and evaporator pressure are 1200 kPa and 227 kPa respectively. Specific volume of refrigerant at the entrance of compressor is 528.26 L/kg. Compression process is polytropic with n = 1.20 and clearance factor of compressor is 2 percent. Determine the horsepower required.

A piston–cylinder assembly contains air modeled
as an ideal gas with a constant specific heat ratio, k =
1.4. The air undergoes a power cycle consisting of
four processes in series: Process 1–2: Constanttemperature expansion at 600 K from p1 = 0.5 MPa to
p2 = 0.4 MPa. Process 2–3: Polytropic expansion with
n = 1.35 to p3 = 0.3 MPa. Process 3–4: Constantpressure compression to V4 = V1. Process 4–1:
Constant-volume heating. Determine (a) the work and
heat transfer for each process, in kJ/kg, and (b) the
thermal efficiency. 

A regenerative gas turbine power plant is
shown in Fig. P1. Air enters the compressor at 1
bar, 27ºC with a mass flow rate of 0.562 kg/s and
is compressed to 4 bar. The isentropic efficiency of
the compressor is 80%, and the regenerator
effectiveness is 90%. All the power developed by
the high-pressure turbine is used to run the
compressor. The low-pressure turbine provides the
net power output. Each turbine has an isentropic
efficiency of 87% and the temperature at the inlet
to the high-pressure turbine is 1200 K. Sketch the
corresponding T – s diagram and determine: (a) The net power output, in kW. (b) The thermal
efficiency. (c) The temperature of the air at states
2, 3, 5, 6, and 7, in K. 

A turboprop engine consists of a diffuser,
compressor, combustor, turbine, and nozzle. The
turbine drives a propeller as well as the
compressor. Air enters the diffuser with a
volumetric flow rate of 83.7 m3
/s at 40 kPa, 240 K,
and a velocity of 180 m/s, and decelerates
essentially to zero velocity. The compressor
pressure ratio is 10 and the compressor has an
isentropic efficiency of 85%. The turbine inlet
temperature is 1140 K, and its isentropic efficiency
is 85%. The turbine exit pressure is 50 kPa. Flow
through the diffuser and nozzle is isentropic. Using
an air-standard analysis, determine: (a) the power
delivered to the propeller, in MW. (b) the velocity at
the nozzle exit, in m/s. Neglect kinetic energy
except at the diffuser inlet and the nozzle exit