Carel kVent, Руководство пользователя

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kVent – rel 3.1 – 22/06/2018
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Steam device doesn’t need antifreeze and frost protection.
5.8 Freeze and frost protections
Water antifreeze 5.8.1
At startup, in case of heating water coils, the start sequence is
divided into the following steps:
1.
The external temperature is checked.
2. If the external temperature is lower than antifreeze
setpoint, the heating devices will be activated in 60s at
power determined by the graph below, then the heating
power will be kept for more time, as in the graph.
3. In case of external temperature greater than antifreeze
setpoint or after the antifreeze sequence timers, the
damper will open.
4. After 30s the fan can start and devices can regulate.
At any time, the back water temperature is checked. If the
temperature is below the freeze threshold (A023), fans are
stopped, the dampers are closed and the heating devices
(main heating and preheating) are forced to 100%. Same
management in case of frost protection by thermostat. Before
the stop of unit by water freeze protection, the heating valve
increase the opening even if there isn’t any request by
thermoregulation.
) * + ,- + .
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Finally, the back water temperature is controlled as the graph
below:
Preheater 5.8.2
The device will modulate accoding to its PID settings to keep
the setpoint based on after preheater coil temperature.
Main goal of this device is prepare air for recovery and to avoid
antifreeze condition for heat recovery device.
The antifreeze procedure of preheater, in case of hot water
coil, is the same of main water heater.
The antifreeze request from back water temperature is added
to main request.
) * + ,- + .
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Recovery defrost 5.8.3
To prevent recovery frost condition that clogs the recovery
device and decrease the efficiency of the unit, kVent provides
a control on external temperature and after preheater device.
If the unit has a preheater, the after preheater temperature is
considered for recovery defrost procedure, else the external
temperature is considered.
kVent defrosts the recovery with timings. Less the external
temperature is, more time kVent keep the recovery in defrost
mode. Below the graph how it works:
Unit external temperature design 5.8.4
In case the external temperature is out of temperature design
(H020 for low limit, H021 for high limit), the unit operates 100%
with mixing damper. If the mixing damper is not present, the
unit stops and damper will close.
5.9 Fans control
Regulation 5.9.1
With control type parameter (I002), the regulation of the fan
can be done according to:
1. None (act according to percentage)
2. CAV regulation
3. VAV regulation
4. Follow supply (for exaust only)
In case of VAV regulation, the air pressure is used as input of
the PID and the setpoint is in Pa.
In case of CAV regulation, the air pressure is used to calculate
the air volume in m3/h.
It’s possible in Setpoint loop to change the fan speed
according to unit mode (Eco, PreComfort, Comfort). The value
is in percentage of the setpoint of the fan in service menu.
The application is able to manage the following type of fans in
ModBus®:
•
Ziehl Abegg®
•
Ebm papst®
0%
100%
Min
Valve
Pump
External temp.
60s power
Max
A065
Min
A064
Low
A061
High
A060
External temp.
Max
A063
Min
A062
Keep time
Back water temp.
Thermostat
Water set
A019
Freeze set
A023
Alarm Alarm PID regulation
A020
A021
Preheater
back water temp.
Thermostat
Water set
A045
Freeze set
A048
Alarm Alarm PID regulation
A046
A047
External temperature
Defrost time
Min
E014
Max time
60s
Max
E013
Defrost disabled
Recovery
defrost
Defrost time
(calculated)
Min Time between defrost
E016
Max Time between defrost
E016a
Defrost enabled
by external
temperature