Printable View
Has anybody any knowledge about this?
As I understand it, Copeland has a solenoid valve that changes the axial compliance from no compression to full compression and a controller that cycles it for temperature control.
No modulation, just on and off cycling.
When the Copeland guys came in here, they explained it as the two rotating scrolls lift up to prevent compression and drop down when it is needed. The solenoid just lifts the scrolls based on the signal from the controller.
This is still in the design stages, but as soon as they are finished, we are going to try one on a small condensing unit.
Hi Dan !
From the little that I know of this, it's definitely modulating. Its uses a modulated compression technology. This is for VCC or varaible capacity control ( a Brazillian manufacturer also claims to have this technology) and is supposed to work like this :
A temperature sensor/controller feeds system capacity demand information to an external solenoid valve which activates loading and unloading of the scrolls. Because this is scroll technology, unloading does not mean cutting-off/in the compressor but varying the point of discharge. ( via ported holes in the fixed scroll member) Some form of PID control must be in play to average between loaded and unloaded states of the compressor.
You could get anywhere between 10% to 90% capacity with this technology.
I think this is what the ASHRAE Handbook calls variable displacement scroll technology or somewhat similar in principle only that the control is digital.
I hope someone from Copeland on this forum can enlighten us ?
Bernard
:D
Thanks Norty !
I think I undestand it better now. But I believe the axial compliance is only on one of the scrolls i.e the orbitting or the fixed and not both. I think the fixed scroll would be the best bet.
I thought this product is already in the market - Copeland was supposed to have developed it with Samsung and this compressor is widely used in S.Korea. It also recently won an award.
Bernard
I don't think they have it ready to go in the US. Every time we talk to Copeland, they say they are not quite ready yet. I don't want to be a ginea (sp?) pig for this....:)
Digital Scroll systems Is it energy efficient both in terms of Connected load and power consumption, as many Utility company charges for connected load in addition to actual power consumption.
How does it compare to Chilled water system especially in power consumption.
The axial compliance in scroll compressors consist in applying pressure on the orbiting scroll so that the lower flanks press on the fixed scroll (and that scoll's upper flanks press on the orbiting scroll) so that little leakage occurs. The device that applies the force is a movable seal that is pressurized through two ports midway between the scrolls. If this seal does not pressurize, the scrolls will move but the leakage through the flanks is high and the scroll does not compress. What the digital scroll has is a solenoid valv that intercepts the pressure of the scrolls and feeds it to the floating seal. Giving the solenoid an electrial pulse train will cause the scroll to compress while the seal is pressurized only. The advantage of this method is that the refrigerant that flows from an inner pocket of the scrolls is discharged to the neighbour pocket outwards and not to the suction pocket, therefore saving work because you only loose the work done between the outward pocket and it's inner neighbor. This is all explained in their Application Engineering bulletin section 21 number 1319.
Quote:
Originally Posted by Dan
try this link for more info
http://www.digitalscroll.com/sb300/portal/home/normal/1
hope this helps