Capacity control

[TRASH101]

Furthermore Hot Gas Injection can be used in 2 ways (maybe more).
1 injected after the expansion device so as too reduce the liquid content in the evap by a small amount of volume displacement and a lot by dumping loads of energy into the evap.

2 injected after the evap. so as to condition the suction vapour without such an impact on the evap.

sorry If this is a little vague but I would have to read up on this to get into the nitty gritty.

Whats the slide valve then and all this d ,dd ,j & k
sounds more like cup sizes to me?

[guapo]

Hi,
I think a,b,c,d are all incorporated in the process of capacity control.

During unloading the slide valve will pull by the hydraulic cylinder it means the effect is throtling the suction, and if the capacity is at the minimum then the hot gas will blow at the suction to mentain the compressor running.

regards

[TRASH101]

Hi again sparrow

Didn`t mean to confuse you. The EEV is just a ropey example of how the throtteling valve works i.e. it works off "normally" a proportional signal which adjusts the valve position, rather like the valve/ actuator arrangement you would find on a low pressure hot water heater battery. The throtling valve must work in conjunction with a normal expansion device.

If you used a solenoid in the system, especially the liquid line, for control modulation you would cause massive problems ,probabley destructive, as solenoids work as on/off devices.

[TRASH101]

cheers paulz

but can you tell me the significance of all the letters
i.e. dd,j etc..

I`ve never come across a slide valve arrangement and would always opt. for variable speed drive for compressor operation when applicable.