Carel Hecu handleiding
Handleiding
Je bekijkt pagina 27 van 60
27
Hecu +0300023EN rel. 1.2 - 14.12.2021
standard
oil separator
capillary
BLDC
compressor
Fig. 6.n
Electronic expansion valve (EEV COMP SPEED)
This solution involves using a CAREL electronic expansion valve. The valve
opening is calibrated based on BLDC compressor operating conditions,
adjusted proportionally according to its speed.
A standard oil separator can be installed to exploit this function. The
control algorithm is represented in the following graph, and the
parameters can be confi gured on screen Fab18.
standard
oil separator
Oil injection valve
BLDC
compressor
V
Fig. 6.o
Opening valve (%)
Compressor
Speed (rps)
Max open. valve
Min open. valve
Min. Speed Max. Speed
Fig. 6.p
Electronic expansion valve (EEV LEVEL MNG)
This solution involves using a CAREL electronic expansion valve. The valve
opening is calibrated based on normal system operating conditions. This
solution is very effi cient from an energy viewpoint, as it injects the exact
quantity of oil needed by the compressor. In order to use this function,
an advanced oil separator needs to be installed, featuring a level sensor
that defi nes three states via two digital inputs, confi gurable on screens
Faa55, Faa56.
An advanced algorithm calculates valve opening based on the time that
elapses between the various states, comparing this against the previous
measurements. The objective is to replicate the oil level inside the
compressor by measuring the amount in the separator and keeping this
level stable over time.
advanced
oil separator
(double oil level)
Oil injection valve
BLDC
compressor
V
Fig. 6.q
On screen Fab20, two preventive thresholds can be set for the high and
low oil level (Emergency HL and LL). If oil remains at that level for the set
time, the valve will open to maximum (case HL) or to minimum (if LL)
moving to 1 step/sec.
Oil speed boost
This function boosts the return of oil by operating the compressor at
a fi xed speed for a set time, thus recovering the oil spread along the
refrigerant circuit.
This override function is activated if the following conditions are true, see
screens Fab15, Fab23:
• Speed boost : YES
• Compressor speed < minimum threshold
• The previous conditions last for a set time
Act. Delay Force time
t
t
rps
Speed Force
Comp. Speed
Thr diff.
Speed Thr
Fig. 6.r
Oil recovery washing
Another function available on Hecu to assist oil return to the
compressor involves washing the evaporators. This function uses serial
communication between Hecu and the MPXPRO or ULTRACELLA
controllers, and the electronic expansion valves on the evaporators.
The oil recovery washing function sets the superheat set point to 0K for
a settable time t1 [default 3 minutes] in order to retrieve the oil spread
along the refrigerant circuit; the valve will thus open further, “washing”
the evaporator and fl ushing the accumulated oil back the compressor.
Notice: to make this function more eff ective, the electronic
expansion valve on the evaporator opens fully at the start of the recovery
washing cycle and then its position is controlled automatically based on
the new superheat set point.
td is the time at the end of a washing cycle for which compressor speed
remains fi xed, and valve opening returns to the same position as prior
to activation of the function [default 2 minutes]. If this value is set to 0,
at the end of a washing cycle the system will restart without overriding
compressor speed and keeping the valve at the previous opening
position for a set time.
Bekijk gratis de handleiding van Carel Hecu, stel vragen en lees de antwoorden op veelvoorkomende problemen, of gebruik onze assistent om sneller informatie in de handleiding te vinden of uitleg te krijgen over specifieke functies.
Productinformatie
| Merk | Carel |
| Model | Hecu |
| Categorie | Niet gecategoriseerd |
| Taal | Nederlands |
| Grootte | 10743 MB |
