Surplus Heat Dumping - Danfoss DHP-R 7Ua User Manual

than the temperature in the cooling tank. The limit Temp diff limit defines how
much cooler it has to be for the valve to the tank to open. There is also a delay
from the start of the brine circulation pump to the opening of the valve, so that
cold brine fluid has time to be pumped up from the hole.
As the cooling integral passes the limit for active cooling a heat pump is star-
ted. The heat pump will lower the temperature on the brine before it enters
the cooling tank. If the integral continues to rise, more heat pumps will be
started.
The valve for active cooling will change position and disconnect the bore hole.
The brine will then circulate only through the cooling tank and the heat pumps,
so that maximum heat is removed from the cooling tank.
2�5�2 surplus heat dumping
The heat produced when a heat pump is started for cooling is, as a first option,
used to make hot water or to warm the building, if such demands exist. When
these demands are met, the heat has to be dumped. This can be done in two
ways. One way is to move the heat from the heat pumps warm side, through a
heat exchanger, over to the brine and store it in the bore hole. The other option
is to vent it away using a surplus chiller. The surplus chiller is activated by the
Config cooling setting.
If the surplus chilleris used, a PI-controller is used to control cooling fans, with
settings for set point, P-area, and I-time.
16 – Danfoss