A Carnot heat engine has an ideal efficiency of 34% and produces
25 kW of output...
A Carnot heat engine has an ideal efficiency of 34% and produces
25 kW of output power. At what rate (MJ/h) must it discharge heat
when operating at full power?
Solutions
Expert Solution
In this problem, first Calculate the
heat input rate to the heat engine from the Carnot ideal efficiency
formula and then Calculate the heat discharge from heat engine by
subtracting output power from heat addition rate and change its
unit from kW to MJ/h as below:-
A heat engine uses a heat source at 580 ∘C and has an ideal
(Carnot) efficiency of 29 % .
To increase the ideal efficiency to 46 % , what must be the
temperature of the heat source?
A gasoline engine has a power output of 150 kW. If its thermal
efficiency is 33%, how much heat must be supplied to keep the
engine running for 18 s to reach the end of a street? (in J) (Note:
express your answer in scientific notation, for instance: 3.14
A Carnot heat engine receives heat at 850 K and
rejects the waste heat to the environment at 298 K.
The entire work output of the heat engine is used to drive a Carnot
refrigerator that removes heat
from the cooled space at -17⁰C at a rate of 450 kJ/min and rejects
it to the same environment at 298
K. Determine;
(a) the rate of heat supplied to the heat engine and
(b) the total rate of heat rejection to...
Professor Modyn wants to power his refrigerator with a heat
engine. A Carnot heat engine receives heat from a reservoir at
493.0°C at a rate of 767 kJ/min and rejects heat to the ambient air
at 29.1°C. The entire work output of the heat engine is used to
drive a refrigerator that removes heat from the refrigerated space
at -3.23°C and transfers it to the same ambient air at 29.1°C.
Note: The IUPAC sign conversion for work is used. Work...
A three phase engine has an usable power of 90 kW and an
efficiency of 91%. The rating plate indicates the following
values:
- 90 kW
- Power factor: 0.89 (i)
- Voltage (volts): 230 delta - 400 wye
Taking as a reference of line voltages V1=V∠90º; direct sequence
and a phase oltage of the supply network of 230 V, find:
a) The phasors of the line and phase voltages of the supply
network
b) The true, reactive and apparent...
A Carnot heat engine within a piston cylinder has 10 kg of air
as the working fluid and operates between 1000 K and 350 K. During
the heat addition process the pressure changes by a factor of 2.5.
The volume at the end of the isentropic compression process is
5m^3. Determine the pressure at each state in kPa and the net heat
of the cue in KJ assuming Constant Heats at 300 K. Draw a P-v and
T-s diagram
A mole of an ideal gas goes through a cycle of a Carnot engine.
Draw the pressure vs volume and entropy vs temperature planes for
this cycle. What do the diagrams look like when the efficiency of
the cycle is 50% and 99%. Then Calculate the work done per cycle by
the gas and find the efficiency of the cycle.
Efficiency of an engine operating condition to Carnot cycle is
equal to ? = 0.45. Temperature and specific volume of the gaseous
working medium at the beginning of isentropic compression are T1 =
600 K and v1 = 0.5 m3/Kg respectively. Find the gas
properties at all other characteristic points of the cycle and the
amount of heat released during isothermal compression. Assume that
the mass of 1Kg of the gas undergoes the sequence of processes
corresponding to Carnot cycle....
what does it imply if the efficiency of an engine is
less than its corresponding carnot efficiency?.Describe two real
life effects that might cause this difference.