The cooling tower is a device used to reject heat and reduce water temperature. counter or cross-flow cooling towers are the two different types of cooling towers based on the airflow pattern. In a counterflow cooling tower, air and water movement are opposite to each other while in a crossflow cooling tower flow of airflow is horizontal and water flow is vertical.
Both the cooling towers counter or cross-flow are having their own advantages and disadvantages. The selection of cross and counterflow cooling tower depends on the user requirement considering various considerations.
Let us discuss which type of cooling tower (counter or cross-flow cooling tower) is best for our need based on different criteria :
|Criteria||Counter Flow Cooling Tower||Cross Flow Cooling Tower|
|Performance||The counterflow cooling tower delivers higher performance than crossflow cooling tower.|
A cooling tower can even be designed with an approach of below 2 Deg C economically.
|A lower approach can also be possible but the space requirement shall be considerably high and it may not be economical for a lower approach design. |
In general performance of crossflow cooling towers are lower than counterflow cooling towers.
|Space Requirement||Space requirement in counter flow cooling tower are low.||Space requirement for similar duty condition are high.|
|Cooling tower footprint||Lower cooling tower footprint.||Higher cooling tower footprint.|
|Maintenance acess||Counterflow cooling towers have limited access for maintenance due to its compact design.||Crossflow cooling towers are having better access for cooling tower maintenance.|
|Water Distribution||Water Distribution in counter flow cooling tower are though header braches, from which piped network of distribution with nozzles are installed.||Water distribution is though nozzles installed in the hot water basin. Gravity is used for water distribution. Rectification of distribution can be done while operation cooling towers.|
|Low load operation||Counterflow cooling tower performance deteriorates below 70% of the hydraulic load.||Crossflow cooling towers can be operated till 30% of hydraulic load without having a major effect on its performance.|
|Water quality||Not suitable for water having higher suspended particles. |
Water quality is very important for operating a counter flow cooling tower.
|Can be operated with higher suspended particles in water. |
Water quality parameters can be relaxed in case of a crossflow cooling tower.
|Air requirement||Qty of airflow requirement is low.||The quantity of airflow requirement is high because of the non-utilization of complete air during cooling tower operation.|
|Fan Pressure head requirement||A higher fan pressure head is required as it has to overcome counter water flow.||No pressure head is required in the system as the head is developed by the hydrostatic head due to gravity.|
|Fan Power requirement||Fan Power is a requirement is high, due to higher pressure head.||Fan Power requirement is low, due to lower pressure head.|
|Water spillage problem||No water spillage problem is faced in the counterflow cooling tower as completer water flow is closed and inside the basin.||In most cross-flow cooling tower, the basin is lower than the cooling tower top, hence water spillage is a common problem faced by this type of cooling tower.|
|Growth of algae||As this cooling tower is closed from the side, cooling tower water is not directly exposed to sunlight therefore algae growth is minimal.||Because of exposer to sunlight algae growth in this type of cooling tower is high.|
|Prone to dirt||Not prone to dirt||This type of cooling towers is more prone to dirt.|
|operating weight||Lighter operating weight||Heavier operating weight.|
|Noise||Nosier than the crossflow tower due to the fall of water.||Quieter operation than counter flow cooling tower.|