Tennessee Tech University Industrial Assessment Center (IAC) students and faculty continue to advance their “Cool Tool” Cooling Tower software, which received a Junior Faculty Research Award in 2015. This macro-enabled Excel based tool aims to help facilities enhance the efficiency of their cooling towers through a series of simulations involving a range of variables.
Why Cooling Towers are Important in Industry - The purpose of a cooling tower is to cool down water that has been heated up due to industrial processes or air conditioning condensers. A cooling tower operates as a heat exchanger that allows water and air to come in to contact with each another to lower the temperature of the hot water (see Figure 1). This is achieved mostly through evaporation as the water circulates through the tower. Cooling towers allow industry to reuse cooling water supplied to their process for heat rejection efficiently and inexpensively.
“Cool Tool” is a macro-enabled Excel file that analyzes an annual base case compared to a revised case of a cooling tower operation. The tool simulates 8,760 hourly calculations for fan power for various fan controls, water consumption, and pumping energy consumption and demand based on the user’s location and its corresponding Typical Meteorological Year 3 (TMY3) weather data. “Cool Tool” simulates up to five cooling tower cells as one tower utilizing one pump or parallel pumping. Through a partnership with Oak Ridge National Laboratory (ORNL), researchers incorporated ORNL’s calculation algorithm in analyzing various fan control technologies for cooling towers. The program provides a summary of the projected annual savings for fan power, water, and pumping results based on the user’s inputs for their base and revised cases. “Cool Tool” can help plants analyze ways to save energy and money at their facility through cooling tower modifications, whether they use it for process cooling or Heating Ventilation and Air Conditioning (HVAC) applications. Users will be able to input their entering/leaving water temperatures based on a monthly operating schedule or a wet-bulb temperature schedule. For the simulation, plants will be able to tell the program whether or not their base and revised case has a variable-frequency drive (VFD) on the fan/pump, drift eliminators, changes in cycles of concentration, reduced water flow rate, etc.
