Idea for better efficiency of REF system

Dear All,

Attached is an idea which i thought and felt that i should share with you all. I would be glad if i can get some valuable suggestions on this system performance.

Hope i will get good suggestion from all good engineers.

thanks
amit

Hi amit
Great idea - but I think it has already been done. Trane centrif chillers use this and call it an ecconimiser and even more advanced with staging. With the pH chart it could be showing a litle more detail like pressure drops thru cond and evap and tev. Keep up advancing these good ideas and apply to other unthought of areas. Another way to improve the liquid line is to use vortex flow. Best of luck.
Tesla

Dear All,

I am expecting more suggestions. Thanks to Tesla.

Amit

The advantage you have is that you feed 100% liquid to the evaporator but you simply can do this when you feed subcooled liquid to it.
How will you control SH to prevent liquid slugging?

Dear Mr. Peter,

What i am looking at is that
1. Liquid supply to the eva. that too at Eva Pressure, which is not possible if we supply with subcooled liquid as there is always 20 ~ 25% flushing comes after the capillary.
2. The superheat is going to be as less as possible because i will supply the flushed vapor during expansion directly to Vapor accumulator which will furthur cool the ref vap. temp to improve upon super heating, there is an additional benefit of suction pressure increase because the pressure of the vapor which is coming out directly after expansion will be more as compared to the vapor coming from EVA.Hence less pressure ratio or less comp. work.

Also for taking care of liquid entry in the comp. is being taken care by the accumlator fixed just before the comp.

your furthur suggestion and queries are most welcomed to make this system more efficient.

Thanks
Amit

What you are trying to do there is called a flash intercooler. Halls have used these for a long time, we use the economiser ports in a screw compressor for free cooling. The liquid has to be at higher pressure than the evap because the liquid will take the path of least resistance and bypass your evap and fill your vessel rather than flow to your evap. You would need to use a back pressure valve on the grey suction line to enable the liquid to flow through the evaporator where, you lose the efficiency of your design due to the higher pressures mixing with the lower pressures and the compressor would then need to be bigger. Nice idea but instead of your flow control valve you would need a pump and then your energy savings are lost. These are called liquid overfeed systems. Good idea but there aren't many things you can do now that havent been tried in the past.

Thanks for your suggestion Halls Engineer.