how do i calculate actual mass flow through a compressor without flowmeters?

[NH3LVR]

scubasteve:

Sorry it took so long to reply. I was out of town as well.
Great pictures! Never knew such compressors could be used on NH3.

You certainly do have some issues. Coming right out of the solenoid valves with no restriction moves the expansion, and wire drawing, to the valve. With having to keep the head pressure up I would guess you are undersized on the pipe sizing, as you are already aware.

One possibility might be to install a pump to boost the liquid line pressure. I have little experience in this area and do not know if anything is available in the size you would require.

I also expect that in your business downtime to make the changes would be hard to come by.

Lowering head pressure to save energy can be a tricky thing unless every aspect is looked at. Our local power company sent people out to the plants in my area and told them to lower the head pressure to save money. All of a sudden the evaporators would not defrost and the oil separators were undersized and every one was unhappy.

That is not to say that it cannot save a lot of energy. I made a small modification to a 770 horsepower installation in Alaska. We got the purger working correctly and dropped the head 30 psi.
The savings in power we were not so concerned with. We picked up enough capacity however that it made a big difference in our capabilities.

Again-thanks for the information and pictures.

[Segei]

scubasteve:

Sorry it took so long to reply. I was out of town as well.
Great pictures! Never knew such compressors could be used on NH3.

You certainly do have some issues. Coming right out of the solenoid valves with no restriction moves the expansion, and wire drawing, to the valve. With having to keep the head pressure up I would guess you are undersized on the pipe sizing, as you are already aware.

One possibility might be to install a pump to boost the liquid line pressure. I have little experience in this area and do not know if anything is available in the size you would require.

I also expect that in your business downtime to make the changes would be hard to come by.

Lowering head pressure to save energy can be a tricky thing unless every aspect is looked at. Our local power company sent people out to the plants in my area and told them to lower the head pressure to save money. All of a sudden the evaporators would not defrost and the oil separators were undersized and every one was unhappy.

That is not to say that it cannot save a lot of energy. I made a small modification to a 770 horsepower installation in Alaska. We got the purger working correctly and dropped the head 30 psi.
The savings in power we were not so concerned with. We picked up enough capacity however that it made a big difference in our capabilities.

Again-thanks for the information and pictures.

NH3LVR
I think that energy savings should be done by the experts not by people from local hydro company. Yes, initial steps of optimization can be done by site engineers but at later stage of this process you need someone who has in depth knowledge of the energy savings in industrial refrigeration.
Steve mentioned about wet bulb control of condensing pressure during summer operation. This is right approach but this control should be set up properly. I saw many plants where engineers have no clue how this control works and why do they need it. Actually, this control is not complicated but nobody explain them how it works and how to check proper operation of this control.