Flash gas in liquid line despite full receiver and good pressures (CO2)
This is on a rack with ~500kg charge, cooling a number of high ceiling storage rooms to -4F.
This is the first time I've seen this with CO2. I've only seen this on undersized Freon racks before. I am suspecting the system or lineset is simply undersized, but I'm posting because there's something I might be missing.
Please don't make me do the metric conversion, but we had 100F outside at the time, receiver pressure is spot on, suction pressure is ~10K below setpoint, superheat of around 10K on every evap, nothing iced up. All looking good.
Rooms are not reaching setpoint. HP is at max, as it should be, and there's a garden sprinkler under the gas cooler, as is the style at the time.
I added a bit of charge because quite often that helps, but receiver is about 1/3 full and the sight glas still isn't clear.
I have a hunch that there's some room for improvement by playing with the pressures to decrease the flash gas content in the liquid line, but I was on-call and didn't have time for experiments.
We have a number of very similar CO2 racks that have no issues running at these temps without irrigation, which again leads me to think that this is a sizing issue.
Is there anything you would try?