Evaporative Cooling

  1. Evaporative Cooling
  2. Fogging
  3. Chiling

Cooling Principle

The basic idea behind this PreCooler technology is the increase of the combustion air density by reduction of the combustion air temperature – through adiabatic cooling. The PreCooler Systems are equipped with high efficiency cooling media available in either Cellulose media or the non-flammable Glasfibre media.

Design Features

  1. Self-supporting or non-self-supporting stainless steel frames for the pads and the mist eliminators.
  2. Pads made of paper fibres or glassfibre material (not flammable).
  3. Water circulating system including stainless steel piping, valves and water tank.
  4. Sensors: Thermometer probe in front of/behind the cooler, conductivity measurement and, if necessary, pH adjustment of the circulating water.
  5. Biocide treatment.
  6. Blow down unit.
  7. Automatic operation and remote start-up and shutdown.
  8. Antifreeze.

Benefits

  1. Increased Power Output :The water is evaporated to pure cold vapour by the PreCooler. This produces a cooling effect which provides an intake air at higher density. This allows the gas turbine to achieve increased power output (at least 5-6%, and up to 60% percent in very hot or dry climates) and increased operating efficiency.
  2. Low Investment and Operational Costs :By using natural principles, the PreCooler has a low investment and operational cost, which allows for very short pay-back periods of 12-24 months. The utility costs of the system are water consumption of normally 0.6-1.3m³ per additional MWH produced and power consumed by the feed pumps which is less than 0.5% of the additional power produced. For new installations is able to offer the additional advantage of integration of the intake air filtration into the PreCooler. This substantially reduces the investment cost of both air filters and coolers by supplying one combined housing.
  3. Simple Installation :Suited for new plants as well as retrofits!
  4. Filtration Ability :An additional benefit of the PreCooler is the air filtration ability. If installed prior to the first filter stage, it will remove approximately 90% of the particles normally removed by the first air filter stage. This significantly increases service life and therefore reduces the maintenance costs. This benefit is also extended to the fine filters, where the dust load is reduced by about 30%.
  5. Noise Control :Due to the PreCooler’s positioning on the intake air system, noise reductions of between 2-10 dB are possible depending on the frequency band.
  6. Low Pressure Drop :Standard pressure drop of a PreCooler is only 50-100 Pa, which is negligible when compared with the pressure drop of 250-1200 Pa by standard air filters. The PreCooler provides aerosol-free cooled air at a constant pressure drop throughout the year.
  7. Long Lasting Media :Typically media is replaced in gas turbines after 6-8 years or even thereafter.

Why use Turbine Air Inlet Evaporative Cooling?

Structured Media Technology

  1. Low initial cost (EUR 20-30 / additional kW).
  2. Increased Power Output – typically between 8-20 % (Increase in cooling of 0.5-1% /°C for gas turbines, 0.05 % /°C for steam turbines).
  3. Increased thermal efficiency (reduced heat rate 0.2 % /°C)
  4. Reduced NOx emissions (0.8-1.5 % /°C cooling)