HI sirs
I've designed a heat pump system and use a suction accumulator to accommodate the winter operation. If it's necessary to add a liquid storage for the capacity variables? pls advise.
regards
LC
Printable View
HI sirs
I've designed a heat pump system and use a suction accumulator to accommodate the winter operation. If it's necessary to add a liquid storage for the capacity variables? pls advise.
regards
LC
If your heat pump is one with small amount of refrigerant charge, perhaps you could use a suction line accumulator to handle the variation in charge requirement in switching between heating/cooling modes. But this is so only if you use a 4-way reversing valve to switch condenser and evaporator to suit demand (cooling or heating). Other switching methods may not have this issue.
However, if the internal volumes of the condenser and evaporator differ very much, you are going to need extra storage capacity during at least one mode of operation, may be during heating/ or cooling depending on the system design, passive volume within the system and the amount of charge
raja
Hi Sir
How do u think if the suction line accumulator to take the task ? heating mode's refrigerant mass flow is about 50% of cooling mode,if the accumulator can store the extra refrigerant ,is it all right?
thanks
LC
What you must bear in mind is the compressor is no more than a glorified suction pump. It will suck as much gas as it can possible get within the constrainst you set it, ie speed, bore, stroke, and effiency. So you cannot store refrigerant in the suction with out affecting the operating parameters of the system.
cheers taz.
What methods besides reversing valves are used in bidirectional heat pumps? Every heat pump I know of uses a reversing valve.Quote:
But this is so only if you use a 4-way reversing valve to switch condenser and evaporator to suit demand (cooling or heating). Other switching methods may not have this issue.
Heat pupms do not have to be bidirectional always. Switching the heat transfer fuid (feeding the application) between the evaporator and condenser to obtain heating/cooling goes well with single direction systems. I do not have examples to post, but this method has been researched, and found better suited for refrigerant mixtures
The excess refrigerant can also be stored at low load conditions in the condenser, a technique used in many chillers (Climaveneta, Carrier, Rhoss, Clivet, Ciat,..)
At low load, you then have at the same time an oversized condenser, so capable of storing refrigerant and even subcool it.