Process Cooling: What Makes Closed-Loop Equipment a Better Choice?

Process Cooling: What Makes Closed-Loop Equipment a Better Choice?

By Laura Davis, Manufacturing Technology Insights | Friday, February 05, 2021

Closed-circuit coolers can also provide dry, sensitive heat rejection when conditions are optimal outside the environment.

FREMONT, CA: Numerous cooling tower manufacturers have a variety of closed-circuit coolers. They are sometimes called fluid coolers for engineers or end-users wanting (or needing) to minimize water usage and repair of equipment as an alternative to heat rejection.

Some cooling applications need a closed-loop system for long-term operation with optimum performance. These kinds of systems usually require terminal units or other related devices of small heat exchangers, which makes maintenance problematic, if possible, at all. Its wide usage for health facilities and offices, hotels, and high-rise residential buildings, such as water-source heat pumps, is among the largest fluid cooler markets. With an open-cooling loop, hundreds of heat exchangers in a condominium or related facilities can become dramatically vulnerable.

High-performance chiller applications, data centers, battery plants, plants for growing rooms, and various manufacturing process loops also require closed-circuit systems. Depending on the form of closed-loop cooling equipment chosen, wastewater is either decreased or removed by evaporation.

Check Out: Top Manufacturing Tech Solution Companies

The same applies to chemicals and processes for water treatment: closed-loop technology can help minimize or even remove the need for system fluid chemical treatment. With a closed-loop system, installation savings can be attained due to the decreased pumping horsepower needed, the removal of an intermediate plate-and-frame heat exchanger, and the abolition of valves and additional pipework. This occurrence is in addition to the lifetime operational savings due to lower water treatment and chemicals, water consumption, and maintenance.

Furthermore, closed-loop devices provide a benefit for cooling systems that run at subfreezing outdoor temperatures. All the open-loop cooling towers should be fitted with basin heaters, a drain back configuration, or a recirculation system for idle periods in freezing conditions.  In comparison, freeze safety is only required for some types of closed-loop equipment.

Closed-circuit coolers can also provide dry, sensitive heat rejection when conditions are optimal outside the environment. This dry ability is an extra advantage that can reduce a project's cumulative water use. Where appropriate, fluid coolers can be sized for complete design or partial load, depending on the dry-bulb switchover temperature. This aspect means that when the cooler fans fully meet the heat load, the recirculating spray pump can be de-energized. While this operational mode decreases the water usage considerably, the recirculating pump still saves electricity.

Weekly Brief

Read Also