Hi everyone,

We are facing a strange issue. After we start up the system we notice quite a lot of drop in compressor discharge flow. Simultaneously the suction pressure drops and temps go down with it. This continues for a while...15-30 minutes. And then suddenly as it appeared, the flow goes back up, pressures return to normal and the temps go back up as well. Several times we've had to turn the system off to prevent any accidents.

My only hypothesis is that somehow we end up in a situation where there's not enough vapor in the liquid pressure receiver which causes low suction pressure and low flow. But thats just a hypothesis and I am not an engineer. Just the owner.

I am attaching pictures of the computer screen for reference. The solid blue line is the evaporator inlet Temp and black line is the outlet. Ignore some of the pressure reading being non-sensical. We're undergoing some PT replacements.

If anyone can help in this matter, I would greatly appreciate it.


PS: forgot to add: the plant is located in Pakistan and we manufacture block ice. We are using ammonia gravity feed.

Screenshot 2023-11-28 at 6.29.47 PM.jpgScreenshot 2023-11-28 at 6.33.24 PM.jpg