Carel pRack pR300T Manual Del Usuario página 26

ENG
If acting on the HPV valve set point, the heat recovery function modifi es the "minimum HPV valve control
set point" parameter (screen Eib28) and is used as the lower limit for calculating the dynamic high pressure
valve pressure control set point.
The increase in this minimum set point from its default value (40.0 barg) to a new minimum set point (e.g. 75
barg) means the system will operate in transcritical conditions even when the gas cooler outlet temperature
is initially lower than the critical value.
This minimum set point can further increased (screen Eeab28) proportional to the heat recovery request, up
to a maximum allowed limit value (e.g. 85 barg).
If the HPV valve set point, calculated based on the gas cooler temperature, exceeds the minimum set point
modifi ed by the heat recovery function, the controller will use this newly calculated set point.
Heat recovery request (%)
Min. request for activation
Heat recovery status
Min set-point HPV
85.0 barg Max HPV set-point
75.0 barg Min HPV set-point
40.0 barg Min HPV set-point
+030220595 - 1.0 - 27.01.2016
100%
0%
1
0
(barg)
(heat recovery ON)
(heat recovery ON)
(heat recovery OFF)
Nota: Activation delay are not consider in this graphic
Fig. 1.b
6
Time