Is a cooling tower a worthwhile investment? (part 3)
Now let’s see how we calculate the size of the tower with the available data:
Let’s suppose that the water flow rate is 15 – 20 – 25 m3/ (m2h), hence we have the size (top view)of the tower. We also have the market price and, hence, the price of the tower.
For the cost of fan power, let’s assume an air velocity of 3.5 m/s. We therefore know the air flow rate to the fan and let’s assume the yield value of the impeller at 70%. It’s now possible to calculate the power absorbed in kW that will be useful to determine the fan power cost.
Using the same method we can also calculate the power absorbed by the pump for the water circulation.
The cost of the installation is calculated to be as much as the cost of the tower.
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Calculations of the cost for the installation of a cooling tower
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m2 tower (20 m3/h m2 approx.)
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1.26
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Cost of the tower
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7,536,000
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Cost for installation
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7.536,000
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Total cost
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15,072,000
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Calculation of the cost for the power of the system with tower
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Energy Consumed
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motor fan motor kW
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1.05
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air flow rate
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13,565
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prevalence mm CA
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20
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motorfan yield
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70%
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pump motor for the movement of water
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5.42
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water flow rate
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25,12
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prevalence m AC supply
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30
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yield of the pump
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70%
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Total kW for circuit tower kW / year
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12,413
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Cost of electricity per year
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1,241,281
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Cost for the make-up water calculated to 5%
m3 / h
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1.3
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Cost of make-up water
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2,411,520
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Cost bleed-off water (= make-up / 2 x cost of water purge)
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602,880
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Cost of maintenance of the tower 5% of the installation cost
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753,600
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Total operative costs
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2,597,761
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Costs Evaluation
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Cost with aqueduct water in one year
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36,172,800
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Operating cost of the system with tower
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2,597,761
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Savings in one year
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33,575,039
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Savings each month
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2,797,920
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Total cost of the tower
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15,072,000
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The investment return (ROI) in MONTHS
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5,4
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Here we can see that the ROI payback period for the tower installation is only 5 and a half months. Because of the small entity involved, financial costs were not taken into account.
All of the above calculations are available upon request. For more information contact us.
