One of the most common concepts in the design and operation of cooling towers is the thermal range (the difference between the inlet and outlet water temperature). However, it is often thought that this parameter depends directly on the tower, when in fact its origin lies in the industrial process itself.
What is the range in a cooling tower?
The range is defined as the difference between:
- HWT (Hot Water Temperature): inlet temperature of the hot water coming from the process.
- CWT (Cold Water Temperature): outlet temperature of the cooled water after heat rejection.
Simply put:
HWT = CWT + Range
Factors that determine the range
The range of a cooling tower is conditioned by two fundamental variables:
- The thermal energy carried by the water: determined by the industrial process served by the tower.
- The water flow rate in circulation: set by the pumping system.
These two factors determine the amount of heat that must be dissipated. Without them, any estimation of the range would be inaccurate and risky.
The role of the cooling tower
The tower does not set the range:
- Its function is to dissipate the heat that comes with the process water.
- A more efficient tower will make the CWT approach the wet bulb temperature (WBT), the theoretical limit of evaporative cooling.
- A less efficient tower will keep the CWT further from this value.
Consequently, the range is a direct reflection of the thermal balance between process and flow rate, not of the tower itself.
Conclusion
The range of a cooling tower is not determined by the tower itself, but by:
- The thermal load generated by the process.
- The pumped water flow rate.
The tower’s role is to optimize heat dissipation under these conditions, ensuring maximum efficiency and system stability.
At Torraval we design and manufacture cooling towers tailored to each industrial process, guaranteeing maximum energy efficiency and optimal operational performance.