A Carnot's engine has a low temperature reservoir at 7 °C with
efficiency of 40%. It...
A Carnot's engine has a low temperature reservoir at 7 °C with
efficiency of 40%. It is desired to increase the efficiency to 50%.
By how many degrees should the temperature of the high temperature
reservoir be increased?
A heat engine operates between a high-temperature reservoir at
610 K and a low-temperature reservoir at 320 K. In one cycle, the
engine absorbs 6800 J of heat from the high-temperature reservoir
and does 2200 J of work.
A) What is the net change in entropy as a result of this
cycle?
1)A geothermal reservoir in Indonesia
has a downhole fluid of water at a temperature of 235°C. The
specific enthalpy of the fluid is 2500 kJ/kg, and consists of two
phases. What is the quality of the steam?
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....
Consider a heat engine that is 40% efficient and operating with
a furnace at a temperature of 727oC with a cooling reservoir at
27oC
•A. If the heat engine withdraws 1MJ/s from the furnace, what is
the rate of entropy loss from the furnace?
•
•B. What would be the rate of entropy gain in the cold
reservoir?
•
•C. What is the total entropy gain of the system?
D. Do A , B, and C again with zero efficiency...
19 - 3 -4
A heat engine operates between a reservoir at 29°C and one at
341°C.
What is the maximum efficiency possible for this engine?
heat engine operates in a Carnot cycle between 88.0°C and 345°C.
It absorbs 21,200 J of energy per cycle from the hot reservoir. The
duration of each cycle is 3.00 s.
(a) What is the mechanical power output of this engine?
kW
(b) How much energy does it expel in each cycle by heat?
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) What is the maximum temperature of the gas? (b) What would be the efficiency of an ideal engine with reservoirs at the maximum and minimum temperatures of this engine? Compare this to the actual efficiency, 0.444.
3 reservoir problem
Reservoir A: 150m
Reservoir B : 125m
Reservoir C : 75m
The pipes from each reservoir meet at junction J. The
characteristics are as follows (all in meters:
La Lb Lc. Da Db Dc
500 1000. 750. 0.75 1 1
What are the friction factors for each pipe?
What is the correct elevation of J in meters ?
What are the flows in each pipe?
Day
High temperature, C
Low temperature, C
1
30
25
2
32
26
3
34
23
4
29
20
5
31
19
6
30
21
7
25
18
The high and low temperatures of each day in Wichita KS are
given in Table. (1 pt) (a) Plot the high temperature for 7 days as
a function of day, i.e., high temperature on y-axis, and day # on
x-axis. Use the red, empty square as a marker with the solid line....
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...