The CTS Chilled Tower^™ W Series uses a two-stage cooling process.

In the upper section, a closed-type, evaporative cooling type tower using the whirlpool multitube method is integrated with a refrigerating cycle condenser.

In the lower section, underneath the water tank for percolated water, there is a machine room for the refrigerating cycle, electrically operated valves and a control panel, all of which are separated from multiple scroll compressors and the water cooler (evaporator).

How the chilled tower works

The outlet temperature control unit, which stabilizes the supply of chilled water, is governed by the control panel based on information supplied by the outlet temperature sensor (T1), the inlet temperature sensor (T2), the atmospheric wet-bulb temperature sensor (T3) and the freeze-proof intermediate temperature sensor (T4).

When the temperature is higher than the external wet-bulb temperature, the chilled water that has returned from the warmed load side is sent to the upper cooling tower. Making use of the latent vaporization heat in the external air sucked in by the fan and in water dispersed by the percolation tank, it is cooled to a temperature close to the atmospheric wet-bulb temperature.

At times when the external wet-bulb temperature is sufficiently low (in autumn, winter and spring), there is no need to run the compressor. The outlet temperature is adjusted by changing the airflow of the external air through RPM control of the fan motor (inverter control). The fan's workload is lightened substantially by this RPM control device. When the external wet-bulb temperature rises (in summer), the system can supply a stable feed of chilled water at a specified temperature by activating the necessary number of compressors to complement the upper cooling tower when it can no longer cool sufficiently on its own. Because the control system only activates the number needed, it is possible to the keep the average operating rate of the compressors low.

In cases where the atmospheric wet-bulb temperature is higher than the return temperature from the load side, cooling loss occurs when coolong water passes through the upper coils and conversely absorbs heat. To prevent this, a record is made of the difference between at the cooling water inlet temperature (T2) and the intermediate temperature (T4). Then, when cooling loss occurs, a mechanism enabling bypass operation is installed.

In the Compact W Series, the upper section houses a proprietary whirlpool multitube method airtight cooling tower and the condenser of the chilling system, while the lower section houses the multiple compressors, water cooler (evaporator), water tank, control panel and other equipment.

How the chilled tower works