Problems with screw chillers at night?
Thread Content
Recently, screw chillers have been experiencing frost formation at night; I’m not sure why this is happening. The liquid level in the ammonia-cooled evaporator isn’t high either, so how can frost formation occur at night? I’m asking an experienced expert to give an explanation regarding chillers!
It is likely caused by an excessive opening degree of the expansion valve or a low exhaust pressure; try reducing the opening degree of the expansion valve, increasing the temperature of the circulating water (condenser cooling water), or reducing the flow rate of the circulating water
Could insufficient purity of liquid ammonia cause liquid carryover?
Do you mean the expansion valve referring to the ammonia cooler and the main ammonia valve?
It is the throttle valve, one of the four key components of a refrigeration system; the refrigerant passes through the throttle valve to have its temperature and pressure reduced before entering the evaporator
We don’t have the device you mentioned here; the ammonia storage tank is connected directly to the ammonia cooler via a gate valve.
Does a gate valve limit flow? Or fully open?
Compilation of materials on ice machines: http://bbs.hcbbs.com/thread-682939-1-1.html. Take a good look – there’s bound to be something you’re looking for!
Of course, there is flow limitation; there are also specifications for the liquid level in the ammonia cooler!
That is, the gate valve acts as a throttle valve