CFD Modeling of an Evaporative Cooling System

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Turbines are used to generate energy from air that flows inside; they are capable of supplying its own energy demand and to generate large quantities of energy. However, many of these turbines operate under variable weather conditions, which affect the overall efficiency. For example, during summer, the air is hot and dry, which means that there is less mass of air flowing inside the turbine compared to the normal operation.

Based on this issue, various methods were developed to solve it. The most reliable solution is to cool down the air inlet using a fogging system. The fogging systems are the most cost-effective method for the reason that it has the lowest installation cost and present larger efficiencies to cool the air inlet. Based on this, a numerical study was performed using STAR-CCM+® v9.04 to investigate the mist dynamics at the turbine’s inlet duct, considering four things:

  1. The water droplets' residence time,
  2. The mass transfer between the water and the air,
  3. Coalescence and agglomeration of the water droplets and,
  4. The changes of density and temperature of the air inside the duct.

Finally, the results were compared against experimental data from a wind tunnel used to measure these variables.

From this study, it was possible to conclude that the results obtained in the simulation were similar to the reported experimentally. In addition, the study provided qualitative results that can help to the design and operation of a fogging system in the air ducts of a turbine.

Author Company: 
Universidad de los Andes
Author Name: 
Jorge López