# refrigeration / water to water heat pump

• 11-15-2012, 12:49 AM
housed
refrigeration / water to water heat pump
Sirius model / french product
The heat pump is a 19KW , water to water

- on low pressure side we have: inlet water 16C, outlet water 12C, pressure of the refrigerant 4.5 bar

- on high pressure side: inlet water 30 C, outlet water 35 C, pressure of the refrigerant is 20 bar

This high pressure is to high for the 35 C water outlet
The top of the compressor is 70C, too hot

If the water outlet is set 40 C we have pressure error (compressor stops)

We recharge the heat pump with R407C, the qty is correct. But the pressures are still to high

When we open fully the expansion valve the low pressure rich 5.5 bar and high one 18 bar / the top the compressor is still 70C
• 11-17-2012, 10:19 AM
Saturatedpsi
Who said 70˚C is too hot or 20 bar too high?
• 11-18-2012, 11:11 AM
housed
20bar is to much for 35c water outlet ...
• 11-18-2012, 05:33 PM
Saturatedpsi
Quote:

Originally Posted by housed
20bar is to much for 35c water outlet ...

I'm not intimately familiar with water source coil applications, but if it's too high, I'd think the problem is over-charge or reduced condensing. Those are usually the causes. Did you measure superheat and subcooling?

You know what the condensing temp is supposed to be, relative to the water temp?
• 11-18-2012, 06:49 PM
housed
Subcooling is 27 k ...

Normal condensing presure is around 15

[
QUOTE=Saturatedpsi;14617201]I'm not intimately familiar with water source coil applications, but if it's too high, I'd think the problem is over-charge or reduced condensing. Those are usually the causes. Did you measure superheat and subcooling?

You know what the condensing temp is supposed to be, relative to the water temp?[/QUOTE]
• 11-18-2012, 08:45 PM
Saturatedpsi
27 k?

How much in Fahrenheit?
• 11-19-2012, 07:14 AM
beenthere
20bars=290PSIG, 4.5bars=65PSIG.
70C=158F.
27K SC = 48.6°F of subcooling.
• 11-19-2012, 08:52 AM
Saturatedpsi
Quote:

27K SC = 48.6°F of subcooling.
That seems like a lot of excess subcooling to me for a high temp application.
• 11-19-2012, 09:18 AM
beenthere
Only has a 7°F water delta across the evap, and 9°F on the condenser.

R407C at 290PSIG is a sat of 118°F, and at 65PSIG is a sat of 42°F.

Chance of a restriction in refrigerant circuit.
• 11-20-2012, 12:31 AM
housed
We made a cleaning with acid solution of the condenser and the situation is back to normal, pressure 16

Quote:

Originally Posted by Saturatedpsi
That seems like a lot of excess subcooling to me for a high temp application.