Dry cooler 1.2
- Dennis De Beuckeleer
The dry cooler 1.2 BC is visualised in the figure below and is used as an end-unit for heating. For instance to release excess heating from the condenser side of a heat pump. In this case, the heat pump works indirectly as a chiller.
Design
To compute the design flows the user has to insert the following parameters.
The dry cooler temperatures can be changed by clicking on the pencil icon. Furthermore, the design heat flow and air volume flow rate can be inserted by the user to calculate the flow rate through the dry cooler.
For the other components external to the BC, the zero load propagation has to be defined as “yes” or no”. The zero load propagation has to be set on “yes” if it’s not part of the full load design condition in the summer when the building requires cooling. This means that from the moment pipes cross the path from the dry cooler to the production units, this thermal power won’t be accounted for. If however, the user wants to summarise the thermal power of the dry cooler and the other end-units, “no” should be selected.
The parameters of the heat exchanger are the following.
The KV-value is necessary to calculate the pressure drop over the heat exchanger at a certain flow rate, which is needed for the pump calculation.
The air volume flow and the UA-value are calculated in the software by doing the action “compute design flows”. It is calculated using the temperatures and thermal power previously mentioned. Both the air volume flow as the UA-value can be changed and locked by the user, in which the design conditions change at the air side of the heat exchanger. You cannot lock both the air volume flow as the UA value.
Simulation
In a simulation, controls are needed to make sure the dry cooler BC does what the user wants it to do. To control the BC correctly, a control signal is needed and should be attached to the square node on the edge of the BC.
If a signal between 0 and 1 is sent to this node, the fans will modulate between 100% flow rate, which is the design flow rate, and 0%.
After a simulation when the user hovers over the BC, the fan electricity consumption is visualised.