Cooling towers are rated in terms of approach and range, where
* the approach is the difference in temperature between the cooled-water temperature and the entering-air wet bulb - twb - temperature<<<<<<<< อันนี้เข้าใจตรงกัน * the range is the temperature difference between the water inlet and exit states
Since a cooling tower is based on evaporative cooling the maximum cooling tower efficiency is limited by the wet bulb temperature - twb - of the cooling air. Cooling Tower Efficiency
The cooling tower efficiency can be expressed as
μ = (ti - to) 100 / (ti - twb) (1)
where
μ = cooling tower efficiency - common range between 70 - 75%
ti = inlet temperature of water to the tower (oC, oF)
to = outlet temperature of water from the tower (oC, oF)
twb = wet bulb temperature of air (oC, oF)<<<< แสดงว่าเมื่อกระเปาะเปียกมาก จะลดประสิทธิภาพการลดอุณหภูมิลง
The temperature difference between inlet and outlet water (ti - to) is normally in the range 10 - 15 oF.
The water consumption - the make up water - of a cooling tower is about 0.2-0.3 liter per minute and ton of refrigeration. Compared with the use and waste of city water the water consumption can be reduced with about 90 - 95%.
Both types are based on evaporative cooling.<<<<แต่อย่างไรก็ตามประสิธิภาพการลดอุณหภูมิทั้งหลายของ cooling tw ก็ยังขึ้นอยู่กับปัจจัยเหล่านี้
* Natural draught cooling towers are more dependent on temperature gradients between air and water and the wind forces than forced draught cooling towers. * The efficiency of natural draught towers are more variable over time and in general lower.
Cooling towers are rated in terms of approach and range, where
* the approach is the difference in temperature between the cooled-water temperature and the entering-air wet bulb - twb - temperature<<<<<<<< อันนี้เข้าใจตรงกัน * the range is the temperature difference between the water inlet and exit states
Since a cooling tower is based on evaporative cooling the maximum cooling tower efficiency is limited by the wet bulb temperature - twb - of the cooling air. Cooling Tower Efficiency
The cooling tower efficiency can be expressed as
μ = (ti - to) 100 / (ti - twb) (1)
where
μ = cooling tower efficiency - common range between 70 - 75%
ti = inlet temperature of water to the tower (oC, oF)
to = outlet temperature of water from the tower (oC, oF)
twb = wet bulb temperature of air (oC, oF)<<<< แสดงว่าเมื่อกระเปาะเปียกมาก จะลดประสิทธิภาพการลดอุณหภูมิลง
The temperature difference between inlet and outlet water (ti - to) is normally in the range 10 - 15 oF.
The water consumption - the make up water - of a cooling tower is about 0.2-0.3 liter per minute and ton of refrigeration. Compared with the use and waste of city water the water consumption can be reduced with about 90 - 95%.
Both types are based on evaporative cooling.<<<<แต่อย่างไรก็ตามประสิธิภาพการลดอุณหภูมิทั้งหลายของ cooling tw ก็ยังขึ้นอยู่กับปัจจัยเหล่านี้
* Natural draught cooling towers are more dependent on temperature gradients between air and water and the wind forces than forced draught cooling towers. * The efficiency of natural draught towers are more variable over time and in general lower.
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Mon 07/Jul/2025
