high pressures

[juma]

Am using semi-hemertic screw-compressor,BITZER HSN7471-75-40P as carbondioxide chiller,refrigerant isR404A.Cooling water temp.74.4F,liquid line temp.75.02F,liquidline after ecolomizer(sub-cooler)temp.69.44F,pressure after filter drier18.4bar,press before filter18.5bar,discharge press 18.6bar,Disch.Temp.167.54F,suction press.1.1bar,suct.temp.-11.38F.Pliz help me solve high discharge pressures?

[Brian_UK]

What is temperature in and out of cooling water circuit?

[frank]

Com'n Brian... read the post

Cooling water temp.74.4F

[Brian_UK]

I know, I saw that, but which way was it going when got that hot?

[Aven]

Am using semi-hemertic screw-compressor,BITZER HSN7471-75-40P as carbondioxide chiller,refrigerant isR404A.Cooling water temp.74.4F,liquid line temp.75.02F,liquidline after ecolomizer(sub-cooler)temp.69.44F,pressure after filter drier18.4bar,press before filter18.5bar,discharge press 18.6bar,Disch.Temp.167.54F,suction press.1.1bar,suct.temp.-11.38F.Pliz help me solve high discharge pressures?

the filters in liquid line need change.

[Magoo]

At 1.1bar suction pressure either the TXV is faulty, or if fitted the danfoss suction strainer has collapsed and restricting suction flow to compressor.
magoo

[Gary]

Looks like overcharge to me.

[NoNickName]

24°C entering condenser, I assume 29°C leaving, 34°C condensing that is 15.6 bar for R404a.
My try: the condenser is filthy and probably overcharged. 10k of subcooling is a lot.

[mad fridgie]

First indication is overcharge, but look at the economiser temp, this is not operating correctly, this would cause incorrect flow through the exapansion valve, possibly backing up liquid in the condensor, giving the effect of overcharge (near flooded, lots of sub cooling and elevated pressure)

[NoNickName]

Yes, I assumed the subcooling is net of economiser.
Otherwise is probably just a filthy or clogged condenser.

[mad fridgie]

If this a shell tube evap (refrigerant on the shell side) could be flooded or DX, then with the econoniser not in operation, a large % of the volume of the shell will be taken up with excess flash gas (passing through the liquid), the liquid which has been replaced with excess flash gas must be held within the condensor, decreasing condensing surface area and increasing sub cooling surface area.
I would expect the liquid after the econ heat exchanger to be closer to 0C (32F)