Cooling Towers

 

CoolingTower:SingleSpeed

CoolingTower:TwoSpeed

CoolingTower:VariableSpeed:Merkel

CoolingTower:VariableSpeed

 

Used in:

 

  • Condenser loop, supply side

 

Cooling towers are placed on the supply side of condenser loops. The cooling tower is modelled as a counter-flow heat exchanger with options for single-speed, two-speed or variable-speed fan. Specifically, 4 types of cooling tower are available:

 

 

Cooling towers here are “wet” and consume water through evaporation, drift, and blow-down. The model can be used to predict water consumed by the towers.

 

The cooling tower seeks to maintain the temperature of the water exiting the cooling tower at (or below) a set point. The set point schedule value is defined by the condenser loop outlet setpoint manager:

 

The Condenser Loop Tutorial includes a useful description of cooling tower operating principles and the Cooling tower dialog

The schematic diagrams below (reproduced with permission from CIBSE) illustrate the various types of Direct & Indirect Heat Rejection used in cooling towers. The condenser process takes the fluid from saturated vapour (point 5) to saturated liquid (point 6) on the graph below.

 

Direct & Indirect Heat Rejection (CIBSE Guide B Table 4.10)

 

Induced Draft Cooling Tower (CIBSE Guide B Table 4.22)