Advising on Heat Pump Efficiency for 1500J at 280K

In summary, the conversation discusses advising a company on a heat pump that claims to deliver 1500J to a room at 280K while consuming 50J of work per cycle. A diagram is drawn and the concept of efficiency is mentioned, specifically the coefficient of performance (COP). The conversation ends with a suggestion to compare the claimed COP with that of a Carnot Cycle heat pump to determine its feasibility.
  • #1
captainjack2000
99
0

Homework Statement


The question asks us to advise the company on a heat pump (and give reasons) which is claimed to deliver 1500J to a room at 280K by consuming 50J of work per cycle pumping heat from the surroundings at 270K.
I've drawn a diagram of the heat pump, taking heat Q2 from a bath of 270K up to an engine/refrigerator into which goes work W=50J, from which heat Q1 goes into hot bath of 280K. I am a bit confused about what to do next.
Is it that the efficiency of a heat pump is = Q1/W = Q1/ (Q1-Q2) = ?

thanks


Homework Equations





The Attempt at a Solution

 
Physics news on Phys.org
  • #2
It's actually referred to as "coefficient of performance" or COP, but yes that is the right idea.

Compare the claimed COP with what you'd get for a Carnot Cycle heat pump operating at those temperatures, to determine whether this COP is possible.
 

1. What is a heat pump and how does it work?

A heat pump is a device that transfers heat from one location to another using a refrigerant. It works by compressing the refrigerant, which causes it to release heat, and then expanding the refrigerant, which absorbs heat. This process allows the heat pump to either heat or cool a space, depending on the direction of heat transfer.

2. How efficient is a heat pump for heating 1500J at 280K?

The efficiency of a heat pump for heating 1500J at 280K depends on various factors such as the type of heat pump, the operating conditions, and the surrounding temperature. However, on average, a heat pump can achieve an efficiency of 200-300%, meaning it can produce 200-300J of heat for every 100J of energy consumed.

3. What is the recommended efficiency for a heat pump?

The recommended efficiency for a heat pump varies depending on the climate and the specific needs of the user. However, the average efficiency for a heat pump is around 250%, which means it can produce 250J of heat for every 100J of energy consumed.

4. Can a heat pump be used for both heating and cooling?

Yes, a heat pump can be used for both heating and cooling. By reversing the direction of heat transfer, a heat pump can either release heat into a space to provide warmth or absorb heat from a space to provide cooling.

5. What are some factors that can affect the efficiency of a heat pump?

The efficiency of a heat pump can be affected by various factors, including the type and size of the heat pump, the operating conditions, the surrounding temperature, and the maintenance of the heat pump. Additionally, the quality and type of insulation in a building can also impact the efficiency of a heat pump.

Similar threads

B Heat pump as a heat engine that operates in reverse
    • Thermodynamics
Replies
3
Views
526
B Thermal physics, COP upper bound for heat driven heat pumps
    • Other Physics Topics
Replies
1
Views
2K
I Maximizing Efficiency: Exploring the Possibility of Self-Running Heat Pumps
    • Classical Physics
Replies
7
Views
1K
B Heat Pumps And The Peltier Effect
    • Thermodynamics
Replies
6
Views
1K
Does a "heat pump" not spew HFCs like an "air conditioner"?
    • Mechanical Engineering
Replies
7
Views
1K
B Can a Heat Pump and Stirling Engine Create a Perpetual Energy Cycle?
    • Thermodynamics
Replies
6
Views
2K
B Lorenz COP of a heat pump and the temperatures of the hot/cold reservoirs
    • Thermodynamics
Replies
3
Views
2K
Heat pump efficiency calculations - Compressor power issue
    • Materials and Chemical Engineering
Replies
23
Views
2K
What factors affect heat rejection in vacuum pump systems?
    • Mechanical Engineering
Replies
3
Views
2K
Heating efficiency of a Heat Pump and a Space Heater
    • Introductory Physics Homework Help
Replies
1
Views
921

Hot Threads

Recent Insights

Back
Top