A couple of weeks ago, we highlighted a dry cooler based Free Cooling System. While that system has its advantages, another option is a system centered around an evaporative cooling tower. As we discussed in our previous post, dry cooling systems provide a very beneficial means of cooling your process in the cool winter months. In this post, we will provide information on the benefits of this system as well as the components required for it to operate.

Most times, when you are utilizing this type of free cooling system, the evaporative cooling tower will be used during the warmer months to cool the condenser on a water cooled central chiller. That way, in the cooler winter months, the chiller can be disabled allowing all of that condenser cooling load to be “switched” over to provide process cooling. All in all, it provides a way to take advantage of the most efficient cooling available to your plant.

The cooling tower based free cooling system features the following items:

• Evaporative Cooling Tower (Comparative to your required system load)
• Cooling Tower Recirculation pump – Recirculates the fluid to the Chiller Condenser or Process load.
  

  Tower Recirculation Pump

• 3-way diverting valve (motorized) – This valve diverts the flow away from the chiller condenser directly to the process load.
• Ambient (Wet Bulb) Temperature sensor – This sensor provides the data to the system that specifies when the switch-over to free cooling should take place.
• Booster pump – Depending on the size of your tower recirculation pump, you may require a booster pump to increase the discharge fluid pressure to a level adequate for your process system pressure drops.
• Optional Secondary Heat Exchanger – This plate & frame exchanger would allow you to keep your tower water and process cooling water separated. It would require an additional pump as well (either existing or new installation).

One of the disadvantages of this system is that cooling tower is inherently dirty. As the water passes through the cooling tower fill, it comes in contact with dust, dirt, leaves, insects, and many other objects that can hinder its performance and cause fouling. That is why we recommend the process feature a Sand & Gravel filter along with an inline mesh filter. With these items, you can minimize the fouling issue.

If you have an application where you think a Free Cooling System may work, please contact our sales team at 281.540.2805 for more information.