What is the formula for finding cooling tower efficiency?
Cooling Tower Efficiency = Range/ (Range + Approach) x 100 In summer the ambient air wet bulb temperature raises when compared to winter thus limiting the cooling tower efficiency.
How is LG ratio calculated?
Considering data from a heat and mass balance the dry air rate and the prevailing L/G ratio in the tower can be calculated: L/G = ha / [Cw x (tw2 – tw1)] = Cw = specific heat of water = 1.0. Obs.: The corresponding KaV/L value has to be established.
How do you calculate the temperature of a cooling tower outlet?
- APPROACH = Cold water temperature – wet bulb temperature.
- = 35oC-25oC.
- =10oC.
- RANGE= Hot water temperature- cold water temperature.
- =42oC-35oC.
- =7oC.
- COOLING TOWER EFFICIENCY= Range/ (range+ approach)*100.
- =7oC/ (7oC+10oC)*100.
How do you calculate air flow in a cooling tower?
The formula is total heat removed (11.2) times pounds per minute of air (6.95) times 60 minutes per hour. 11.2 X 6.95 X 60 = 4, 670.4 BTU/Hr. Therefore, a tower with a 100 CFM motor at these conditions would be removing 4,670.4 BTU/Hr.
How do you evaluate cooling tower performance?
Cooling Tower Thermal Efficiency Calculations
- Approach = Cold Water Temperature – Wet Bulb Temperature.
- Range = Hot Water Temperature – Cold Water Temperature.
- Cooling Tower Thermal Efficiency = Range/ (Range + Approach) x 100.
- COC = Silica in Cooling Water / Silica in Makeup Water.
How do you calculate blowdown in a cooling tower?
It is calculated by this equation:
- Evaporation loss = 0.00085 Wc (T1-T2)
- Drift loss = 0.02% water supply [for new development in eliminator design]
- Blowdown = [ Evaporative loss – (COC – 1) x Drift loss] /(COC – 1)
How is cooling capacity of a cooling tower calculated?
Multiply 500 times the water flow rate, times the temperature difference, divided by 12,000 or 500 x q x dt/12,000. The result is the tons of capacity of the cooling tower.
How do you calculate gpm for a cooling tower?
Heat Load (BTU/Hr) = GPM X 500 X ° Range of cooling, or rearranged to determine the design flow rate. GPM = Heat Load (BTU/Hr) = 6,250,000 Btu/Hr = 835 gpm 500 X ° Range of cooling 500 x 15° R Now you can make your cooling tower selection based on 835 gpm, cooling from 98°F to 83°F @ a design 76°F Twb.
What is the Merkel equation used for?
Merkel’s method is the most widely accepted theory for cooling tower calculations. It combines equations for heat and water vapor transfer. The objective of this paper is to present the design procedure of counter – flow cooling towers in a simplified manner.
How is sump capacity of cooling tower calculated?
Estimate the system volume by measuring the sump of the tower and the water level in it. Multiply the number of cubic feet of water by 7.5 to get the number of gallons.
How do you calculate cooling capacity?
Calculating a Home’s Cooling Load
- Determine the dimensions of the room or home that needs cooling. For a room, you can do this with a measuring tape.
- For a room, multiply its length by its width to get the square footage.
- Multiply the square footage by 20. This is the measure of the BTU cooling load of the space.
How do you calculate the rate of cooling?
Calculate the cooling rate by dividing each temperature data point by its corresponding time data point then average all of your answers to achieve a cooling rate. In other words, the change in the temperature divided by the change in time will give you an average temperature rate change.
What is the capability of a cooling tower?
The capability of the cooling tower is a measure of how close the tower can bring the water temperature to the WBT of the entering air. A larger cooling tower [i.e., more air and/or more fill] will produce a closer approach [colder leaving water] for a given heat load, flow rate and entering air condition.
What is adjusted hot water temperature in cooling towers?
Although the area ABCD should remain constant, it actually decreases about 2% for every 10 °F increase in hot water temperature above 100 °F. To account for this decrease, an “adjusted hot water temperature” is usd in cooling tower design.
Why is the number 500 independent of the cooling tower?
The number 500 is a constant, therefore is independent of the cooling tower. The circulating water flow is determined by the number of pumps running and the pressure drop in the overall circulating water system. Therefore, it likewise is independent of the cooling tower.
What is the loss of water from the cooling tower?
There is a penalty involved, and that is loss of water which goes up to the cooling tower and is discharged into the atmosphere as hot moist vapor. Under normal operating conditions, this amounts to approximately 1.2% for each 10 oF cooling range.
