2 replies to this topic

[telfener]

In my present research, I need to pressurize a one-component (e.g. R134a) two-phase fluid, that is constituted by the liquid phase and vapor phase.
During this compression process, a phase change takes place (the fluid is inside the bell in T-S diagram).

I think two-phase compressors or two-phase diffusers could be able to do this.

Could you suggest me some paper, patent with theoretical or empirical study?

Thanks

[Art Montemayor]

Telfener:

I am not throwing cold water on your idea, but proposing to compress a 2-phase fluid (even though it may be saturated) is a risky business. You stand to ruin – or worse, destroy the compressor – should things not go precisely “right”. And this applies only to certain types of compressors. Reciprocating – or most positive displacement types – would certainly be excluded. I have never heard, read, or discussed this topic with or from some of the compressor experts I have associated with or consulted. That, of course, doesn’t mean that it isn’t possible or that someone isn’t working on this application from a machinery design point. I just want to emphasis that no compressor expert that I know has ever accepted a 2-phase flow within a compressor – be it dynamic (centrifugals) or positive displacement (recips, screws, etc., etc.). And I have never heard of a compressor manufacturer guaranteeing or warranting this type of operation.

I would hate to admit it in public, but I have run some liquids through screw compressors – never on purpose and certainly not according to design. Most of the incidents were accidental or instrument / operator errors and I would never repeat the incidents. I did experience some seal damage, but the compressor reverted back to normal. I believe I was lucky.

What type, size, and configuration of compressor are you thinking about or planning?

[telfener]

Art Montemayor,

first of all thanks for your answer.
At the moment, I don't know which type of device could be useful for my research.

Multi-phase pump, currently employed in oil&gas industry, maybe could be useful: they are able to work with a multi-component fluid constituted by liquid phase and vapor phase. But the compression process must be WITHOUT phase change. So liquid phase remains liquid and vapor phase remains vapor during this process. So it is necessary to modify the design of multi-phase pumps in order to pressurize a one-component two-phase fluid.

Recently, I read some papers where some authors performed theoretical and empirical studies on a traditional scroll compressor or traditional centrifugal compressor that pressurizze a refrigerant vapor with liquid injection. In this way the performance of the compressor are better. This studies, I think, could be a good starting point to develope a two-phase fluid compressor.

Another possibility is two-phase fluid diffuser.

What do you think about it?