Gazi Üniversitesi/Gazi University
Mühendislik-Mimarlık Fakültesi/Faculty of Engineering and Architecture
Makina Mühendisliği Bölümü/Mechanical Engineering Department
Ankara/Türkiye
Instructor: Dr. Atilla Bıyıkoğlu
15.03.2022
ME204 THERMODYNAMICS-II
HOMEWORK-III
2021-2022 SPRING
DUE ON MARCH 20th, 2022
(%30) Q1. A supply of geothermal hot water is to be used as the energy source in an
ideal Rankine cycle. Saturated vapor refrigerant leaves the boiler at a
temperature of 85°C, and the condenser temperature is 40°C. Calculate the
thermal efficiency of this cycle using; a) R-134a, b) R-22 and, c) Ammonia
as the cycle working fluid. Compare and comment on the results.
(%35) Q2. A smaller power plant produces steam at 3 MPa, 600oC in the boiler. It keeps
the condenser at 45°C by transfer of 10 MW out as heat transfer. The first
turbine section expands to 500 kPa and then flow is reheated followed by the
expansion in the low-pressure turbine. Find the reheat temperature so the
turbine output is saturated vapor. For this reheat find the total turbine power
output and the boiler heat transfer.
(%35) Q3
.
A Rankine cycle operating with ammonia is heated by some low temperature
source, so the highest T is 120°C at a pressure of 5000 kPa. Its low pressure
is 1003 kPa and it operates with one open feedwater heater at 2033 kPa. The
total flow rate is 5 kg/s. Find the extraction flow rate to the feedwater heater
assuming its outlet state is saturated liquid at 2033 kPa. Find the total power
to the two pumps.