View Full Version : accumulator (header)

14-10-2013, 07:15 PM
Does the accumulator nact more like a reservoir to prevent liquid refrigerant from flooding into the suction line or a small storage tank for refrigerant. Took a class and these were some of the questions asked. Too me a would think small storage tank

The Viking
14-10-2013, 07:56 PM
Let's think about this...

The refrigerant exit the compressor as a high pressure superheated vapour and goes in to the condenser where it is condensed in to a sub-cooled liquid. This liquid is then taken in to the accumulator before it goes to the metering device (orifice/capillary tube/expansion valve) which cause a reduction in pressure and adjust the refrigerant flow to suit the evaporator where the liquid refrigerant evaporates before it is taken back to the compressor as a low pressure superheated vapour.

Now, if you look at that explanation what part of the system is reducing the flow of refrigerant in to the suction line?


14-10-2013, 08:42 PM
Well the liquid gets store (accumlates) in the tank and pulls the vapor off to send to compressor. To me a reservoir pools the liquid, even though the accumlators purpose is so liquid refrigerant from flooding the suction line. Still lost as both could be correct. But then again the purpose of the auccumulator isnt just to store refrigerant but to protect compressor. So Ive chaged my answer to a reservoir to prevent liquid refrigerant from flooding into the suction line

The Viking
14-10-2013, 09:19 PM
The task for the accumulator is actually to ensure there is a solid liquid supply to the metering device.
And the metering device's task is to ensure that there isn't too much refrigerant going through the evaporator and in to the suction side.

With varying demands you will need a varying amount of refrigerant flowing through the system and with varying conditions across the condenser you might get uncondensed refrigerant passing through it, this is why you need an accumulator, to even out the amount of refrigerant and to ensure there is a solid liquid supply to your metering device.

As the accumulator is on the liquid side of the system it can not affect the suction side. (Assuming correct sizing and design of the system)


14-10-2013, 09:29 PM
HMMMM then what is the purpose of a suction line accumulator? Thought it was to catch any liquid refrigerant that hasnt evaporated before going to compressor. I might be wrong thou but thought it was placed in the suction line ahead of the compressor and was to prevent flood back on the cooling cycle and floodback in heating and temination of the deforst cycle cause liquid floodback will always occur when the defrost cycle is terminated. But then again I might be wrong

14-10-2013, 09:31 PM
And its purpose is to ensure that no liquid reaches the compressor and you know the condenser is to ensure 100% liquid reaches the meter device. But I know you were clowning me cause you know that the accumulators purpose is to protect the compressor from liquid referigerant which will leave the evap coil durning light loads or if airflow is decreased acrossed the coil. Why would you have accumulator in the liquid line??

14-10-2013, 10:30 PM
I think there is a terminology problem developing here.

In the UK, at least, the liquid refrigerant after the condenser is collected in a 'receiver' whereas an 'accumulator' is fitted into the compressor suction line to protect the compressor from liquid flood back.

The receiver is fed liquid and often has a dip tube to the bottom of the vessel to feed the liquid out to the expansion device.

The accumulator on the other hand can accept saturated vapour but has a 'U' tube exiting the top of the vessel. The U-tube has an open end near the top of the vessel so that only vapour is drawn out.
The bottom of the U-tube has a small hole in it to recover any oil that gathers at the bottom.