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(2) Cooling tower
a) Types of cooling tower
The cooling towers presently used include the open type cooling
tower, open type cooling tower + heat exchanger, closed type
cooling tower, and air-cooled type cooling tower.
However, as the quality control of circulation water is essential
when units are installed in decentralized state inside a building, the
closed type cooling tower is generally employed in such case.
Although the circulation water will not be contaminated by
atmospheric air, it is recommended to periodically blow water
inside the system and replenish fresh water instead.
In a district where the coil may be frozen in the winter, it is
necessary to apply antifreeze solution to the circulation water, or
take freeze protection measures such as to automatically
discharge water inside the cooling coil at the stopping of the pump.
When the open type cooling tower is used, be sure to install a water
quality control device in addition to the freeze protection measures,
as the water may be deteriorated by atmospheric contaminants
entered into the cooling tower and dissolved into the circulation
water.
b) Calculation method of cooling tower capacity
All units of the water heat source CITY MULTI may possibly be in cooling operation temporarily (at pulling down) in the
summer, however, it is not necessary to determine the capacity according to the total cooling capacity of all CITY MULTI
units as this system has a wide operating water temperature range (10~45°C) [50~113°F].
It is determined in accordance with the value obtained by adding the maximum cooling load of an actual building, the input
heat equivalent value of all CITY MULTI units, and the cooling load of the circulating pumps. Please check for the values of
the cooling water volume and circulation water volume.
Types of cooling towers
Closed type
Air-cooled type
Cooling tower capacity = (Refrigeration ton)
Qc :
Maximum cooling load under actual state
(kcal/h)
Qw :
Total input of water heat source CITY MULTI at simultaneous operation under
maximum state
(kW)
Pw :
Shaft power of circulation pumps
(kW)
Qc + 860 x (ΣQw + Pw)
3,900
Cooling tower capacity = (Refrigeration ton)
Qc :
Maximum cooling load under actual state
(BTU/h)
Qw :
Total input of water heat source CITY MULTI at simultaneous operation under
maximum state
(kW)
Pw :
Shaft power of circulation pumps
(kW)
*
1 Refrigerant ton of cooling tower capacity ≈ US refrigerant ton x (1+0.3)
= 3,900 kcal/h = 15,500 BTU/h
Qc + 3,412 x (ΣQw + Pw)
15,500
Summary of Contents for PQHY-P250YHM-A
Page 1: ...DATA BOOK PUHY P250YJM A BS PUHY P500YSJM A BS PQHY P250YHM A PFD P250VM E PFD P500VM E MODEL ...
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