Pro/Forums - View Single Post - What factors influence the performance of a phase change evaporator block?

8-Ball · 02-04-2004, 06:35 AM

I have been looking through the xtremesystems.org forums into the designs of evaporators.

The fact that a phase change is taking place makes it a lot more difficult to produce an evaporator which functions well. A few key points.

You need to think about the orientation of the block. Remember that there will be a mixture of liquid and vapour in the block. Ideally, you don't want liquid refrigerant returning to the compressor, but equally, you DO want some way of ensuring that the oil mixed in with the coolant DOES get back to the compressor.

Narrow channels promote a high velocity of refrigerant which can drive the oil back to the compressor and is a good solution, provided you can guarantee that all of the refrigerant vapourises.

To be honest, I don't really know enough about the subject to be able to help, though I would suggest looking at the aforementioned forums. There are a lot of knowledgable guys there working with some pretty remarkable phase change setups. (Think -100degC in a dual compressor cascade system!!!)

8-ball

02-04-2004, 06:35 AM	#6
8-Ball Cooling Savant Join Date: Feb 2002 Location: Oxford University, UK Posts: 452	I have been looking through the xtremesystems.org forums into the designs of evaporators. The fact that a phase change is taking place makes it a lot more difficult to produce an evaporator which functions well. A few key points. You need to think about the orientation of the block. Remember that there will be a mixture of liquid and vapour in the block. Ideally, you don't want liquid refrigerant returning to the compressor, but equally, you DO want some way of ensuring that the oil mixed in with the coolant DOES get back to the compressor. Narrow channels promote a high velocity of refrigerant which can drive the oil back to the compressor and is a good solution, provided you can guarantee that all of the refrigerant vapourises. To be honest, I don't really know enough about the subject to be able to help, though I would suggest looking at the aforementioned forums. There are a lot of knowledgable guys there working with some pretty remarkable phase change setups. (Think -100degC in a dual compressor cascade system!!!) 8-ball __________________ For those who believe that water needs to travel slowly through the radiator for optimum performance, read the following thread. READ ALL OF THIS!!!!