At steady state, a heat pump driven by an electric motor maintains the interior of a...
At steady state, a heat pump driven by an electric motor
maintains the interior of a building at TH =
293 K. The rate of heat transfer, in kJ/h, from the building
through its walls and roof is given by 8000(TH
- TC), where TC is the
outdoor temperature.
Determine the minimum electric power, in kW, required to drive the
heat pump for TC = 255 K.
Homework Answers
Add Answer to:
At steady state, a heat pump driven by an electric motor
maintains the interior of a...
A heat pump is to be used to heat a house in winter and then reversed...
A heat pump is to be used to heat a house in winter and then
reversed to cool the house in summer. The interior space is to be
maintained at 20oC. Heat transfer through walls and roof is
estimated to be χ = 0.525 kJ/sec per degree difference in
temperature between inside and outside. (6a) (8p) In winter if the
outside temperature is 5oC, what is the minimum power required to
drive the heat pump? (6b) (12p) For the same...
5.75 A heating system must maintain the interior of a building at TH = 20 degree C when the outside temperature is T =...
5.75 A heating system must maintain the interior of a building at TH = 20 degree C when the outside temperature is T = 2 degree C. If the rate of heat transfer from the building through its walls and roof is 16.4 kW, determine the electrical power required, in kW, to heat the building using (a) electrical-resistance heating, (b) a heat pump whose coefficient of performance is 3.0, (c) a reversible heat pump operating between hot and cold reservoirs...
A Stirling-engine is used in the heat-pump mode to heat a house. The engine maintains a...
A Stirling-engine is used in the heat-pump mode to heat a house. The engine maintains a temperature of 20.5 °C inside the house. The temperature of the Earth loop is 14.1 °C. (The Earth loop buried deep under the ground is the cold reservoir of this heat pump.) What is the coefficient of performance of this heat pump? Tries 0/12 If the power of the electric motor driving the heat pump is 157 W, then what is the rate at...
1. At steady state, an electric motor develops 2 kW of power along its output shaft while drawing...
Please show how the written numbers were found. No need to
find %’s
1. At steady state, an electric motor develops 2 kW of power along its output shaft while drawing 20 amps at 120 V. The outer surface of the motor is at 50°C. Complete a full exergy accounting for the motor using the table below as a guideline. Exergy, kw % of total exergy in Exergy in .Electricity at w n/a Exergy out Shaft power . Heat transfer...
At steady state, a heat pump provides 30,000 Btu/h to maintain a dwelling at 68°F on...
At steady state, a heat pump provides 30,000 Btu/h to maintain a dwelling at 68°F on a day when the outside temperature is 35°F. The power input to the heat pump is 5 hp. If electricity costs 8 cents per kw . h, compare the actual operating cost with the minimum theoretical operating cost for each day of operation. The actual operating cost: $/day. The minimum theoretical operating cost: $/day.
Needed help in this question! URCES Problem 5.64 At steady state, a heat pump provides 30,000...
Needed help in this question!
URCES Problem 5.64 At steady state, a heat pump provides 30,000 Btu/h to maintain a dwelling at 68°F on a day when the outside temperature is 50°F. The power input to the heat pump is 5 hp. If electricity costs 8 cents per kW h, compare the actual operating cost with the minimum theoretical operating cost for each day of operation. The actual operating cost: $/day. The minimum theoretical operating cost: $/day. By accessing this...
Question 1 During steady state operation, a gear box receives 60kW through the input shaft and...
Question 1 During steady state operation, a gear box receives 60kW through the input shaft and delivers power through the output shaft. For the gearbox as the system, the rate of energy transfer by convection is given by Q=-hA(Tb - T) Where h 0.171kW/m2.k is the heat transfer coefficient, A=1.0m2 is the outer surface are of the gearbox. Tb 300k is the temperature at the outer surface and T 293 K is the temperature of the surrounding air. For the...
02. [HW] Textbook problem 6-160 (6 marks) A heat pump receives heat from a lake that...
02. [HW] Textbook problem 6-160 (6 marks) A heat pump receives heat from a lake that has an average winter time temperature of 6°C and supplies heat into a house having an average temperature of 27° C. (a) If the house loses heat to the atmosphere at a rate of 64000 kJ/h, determine the minimum power supplied to the heat pump, in kW. (b) A heat exchanger is used to transfer the energy from the lake water to the heat...
US PRINTER VERSİON "ACKIC I Problem 5.044 SI A heat pump cycle is used to maintain...
US PRINTER VERSİON "ACKIC I Problem 5.044 SI A heat pump cycle is used to maintain the intenior of a building at 20°C. At steady state, the heat pump receives energy by 9eC and discharges energy by heat transfer to the building at a rate of 120,000 k/h. Over a period of 14 days, an electric meter records that 2000 kw-h of electricity is provided to the heat pump. Determine: (a) the amount of eneroy that the heat pump receives...
A closed chamber containing a gas is at steady state. The shaft transfers power at a...
A closed chamber containing a gas is at steady state. The shaft
transfers power at a rate of W˙sh,in= 2.0 kW to the paddle
wheel and the electric lamp consumes electricity at a rate of
W˙el,in= 700 W .
A) Using an energy balance determine the rate of heat transfer,
in kW.
B) If the surface temperature of the chamber is 430 K ,
determine the entropy generated within the chamber, in kW/k
C) What would the entropy generation within...
A heat pump is to be used to heat a house in winter and then
reversed to cool the house in summer. The interior space is to be
maintained at 20oC. Heat transfer through walls and roof is
estimated to be χ = 0.525 kJ/sec per degree difference in
temperature between inside and outside. (6a) (8p) In winter if the
outside temperature is 5oC, what is the minimum power required to
drive the heat pump? (6b) (12p) For the same...
5.75 A heating system must maintain the interior of a building at TH = 20 degree C when the outside temperature is T = 2 degree C. If the rate of heat transfer from the building through its walls and roof is 16.4 kW, determine the electrical power required, in kW, to heat the building using (a) electrical-resistance heating, (b) a heat pump whose coefficient of performance is 3.0, (c) a reversible heat pump operating between hot and cold reservoirs...
Please show how the written numbers were found. No need to
find %’s
1. At steady state, an electric motor develops 2 kW of power along its output shaft while drawing 20 amps at 120 V. The outer surface of the motor is at 50°C. Complete a full exergy accounting for the motor using the table below as a guideline. Exergy, kw % of total exergy in Exergy in .Electricity at w n/a Exergy out Shaft power . Heat transfer...
At steady state, a heat pump provides 30,000 Btu/h to maintain a dwelling at 68°F on a day when the outside temperature is 35°F. The power input to the heat pump is 5 hp. If electricity costs 8 cents per kw . h, compare the actual operating cost with the minimum theoretical operating cost for each day of operation. The actual operating cost: $/day. The minimum theoretical operating cost: $/day.
Needed help in this question!
URCES Problem 5.64 At steady state, a heat pump provides 30,000 Btu/h to maintain a dwelling at 68°F on a day when the outside temperature is 50°F. The power input to the heat pump is 5 hp. If electricity costs 8 cents per kW h, compare the actual operating cost with the minimum theoretical operating cost for each day of operation. The actual operating cost: $/day. The minimum theoretical operating cost: $/day. By accessing this...
Question 1 During steady state operation, a gear box receives 60kW through the input shaft and delivers power through the output shaft. For the gearbox as the system, the rate of energy transfer by convection is given by Q=-hA(Tb - T) Where h 0.171kW/m2.k is the heat transfer coefficient, A=1.0m2 is the outer surface are of the gearbox. Tb 300k is the temperature at the outer surface and T 293 K is the temperature of the surrounding air. For the...
02. [HW] Textbook problem 6-160 (6 marks) A heat pump receives heat from a lake that has an average winter time temperature of 6°C and supplies heat into a house having an average temperature of 27° C. (a) If the house loses heat to the atmosphere at a rate of 64000 kJ/h, determine the minimum power supplied to the heat pump, in kW. (b) A heat exchanger is used to transfer the energy from the lake water to the heat...
US PRINTER VERSİON "ACKIC I Problem 5.044 SI A heat pump cycle is used to maintain the intenior of a building at 20°C. At steady state, the heat pump receives energy by 9eC and discharges energy by heat transfer to the building at a rate of 120,000 k/h. Over a period of 14 days, an electric meter records that 2000 kw-h of electricity is provided to the heat pump. Determine: (a) the amount of eneroy that the heat pump receives...
A closed chamber containing a gas is at steady state. The shaft
transfers power at a rate of W˙sh,in= 2.0 kW to the paddle
wheel and the electric lamp consumes electricity at a rate of
W˙el,in= 700 W .
A) Using an energy balance determine the rate of heat transfer,
in kW.
B) If the surface temperature of the chamber is 430 K ,
determine the entropy generated within the chamber, in kW/k
C) What would the entropy generation within...
Most questions answered within 3 hours.
-
a radio station transmits at 78.1 mhz. a hz is an inverse
second. how far apart...
asked 18 seconds ago -
Write the equilibrium expression for the dissociation in
water for CH5N, C2H5O2COOH, H3AsO4, KClO2, HC2H2ClO2.
asked 5 minutes ago -
In risk management, insurance is an example of:
Select one:
a. Risk avoidance
b. Risk deflection...
asked 7 minutes ago -
Wildhorse Company follows the practice of pricing its inventory
at the lower-of-cost-or-market, on an individual-item
basis....
asked 41 minutes ago -
3. (10 pts) You grow a corn crop that yields 150 bushels ac-1,
with the following...
asked 30 minutes ago -
7. The term Six Sigma refers to:
Select one:
a. The control limits established in a...
asked 40 minutes ago -
For the following reaction: A(g) + 2 B(g) ⇌ 2 C(g) Calculate the
equilibrium constant K...
asked 42 minutes ago -
Which of the following best describes tidal volume? options:
1.The amount of oxygen in the air...
asked 58 minutes ago -
1. Smaller cost distortions occur when the traditional systems'
single indirect-cost rate and the activity-cost-driver rates:...
asked 1 hour ago -
Using either a FMECA approach or some other appropriate RCA
tool, identify five risk treatment actions...
asked 1 hour ago -
If for a test the P-value is between 0.0025 and 0.005, what
conclusion can you draw?...
asked 1 hour ago -
Using Python. Write a function clean2(aList) that takes a list
of integers aList as argument, and...
asked 1 hour ago