I Heat pumps: Questions about compressor pump refrigerant gas and evaporator

Click For Summary
A heat pump operates as a sealed unit containing refrigerant, with the compressor increasing pressure by compressing gas from the evaporator into a high-pressure space. The discussion explores how the compressor functions, comparing it to a bicycle pump, and clarifies that the system does not draw additional gas from outside but compresses the existing refrigerant. Questions arise about the evaporation and condensation processes occurring at constant pressure despite the fixed volume of the refrigerant. The participants also discuss the implications of pressure and temperature changes during the heat pump cycle, particularly when using propane as a refrigerant. Overall, the conversation emphasizes the mechanics of heat pump operation and seeks to clarify misunderstandings about the compression process.
  • #31
GreenWombat said:
Hi Russ. In your contribution (Saturday, 24 August), you wrote that the pressure drop across the evaporator was “too small to be visible on the P-V diagram and can be ignored.” For me, that was brilliant because it resolved the contradiction of (1) the pressure-volume diagram showing constant volume and (2) refrigerant moving across the evaporator without any pressure drop.
My error: I meant "the pressure-volume diagram showing constant pressure"
 

Similar threads

B Cooling effect of evaporation occurs even if the surroundings are colder?
  • · Replies 10 ·
Replies
10
Views
2K
I Do refrigerants passing through a venturi act like steam?
  • · Replies 8 ·
Replies
8
Views
2K
B Heat Pumps And The Peltier Effect
  • · Replies 6 ·
Replies
6
Views
2K
Heat pump efficiency calculations - Compressor power issue
  • · Replies 23 ·
Replies
23
Views
4K
I Trying to wrap my head around gas turbine thermodynamics
  • · Replies 5 ·
Replies
5
Views
3K
OUNT OF HEAT ABSORBED AND GIVEN OUT BY REFRIGERANT IN HEAT PUMP
  • · Replies 1 ·
Replies
1
Views
2K
Why did the superheat go up as I added refrigerant?
  • · Replies 18 ·
Replies
18
Views
7K
Question about Refrigerants used within a Heat Pump
  • · Replies 5 ·
Replies
5
Views
2K
What factors affect heat rejection in vacuum pump systems?
  • · Replies 3 ·
Replies
3
Views
3K
I How to calculate the mass of gas in a tank?
  • · Replies 109 ·
4
Replies
109
Views
7K