July 29, 2014

The Coolerado Cooler for Combustion Turbine Cycles

POWER magazine, by Platts/McGraw Hill

The Coolerado Cooler for Combustion Turbine Cycles

POWER magazine, by Platts/McGraw Hill
November / December 2003
A supplement to the POWER magazine article
By Ken Wicker
Link to Article

According to GE: “An inlet cooling system is a useful gas turbine option for applications where significant operation occurs in the warm months and where low relative humidities are common. The cooled air, being denser, gives the machine a higher mass-flow rate and pressure ratio, resulting in an increase in turbine output and efficiency. This is a cost-effective way to add machine capacity during the period when peaking power periods are usually encountered on electric utility systems.”

However, inlet cooling with vapor compression systems can be cost prohibitive for the amount of energy gained as compared to the power used for cooling. Also, fogging and evaporative cooling systems can introduce water into the compressor, causing blade erosion and voiding the warranty on the system.

The Coolerado Cooler offers a new and better method. To gain maximum air density, it is best to cool the air without adding moisture. This is called sensible cooling, and it follows the horizontal constant humidity line labeled ‘Coolerado Cooler.’ Sensible cooling is more perpendicular to the constant volume line, resulting in a much greater increase in air density.

Adiabatic cooling is achieved by adding moisture to the air, but no work is actually done. This is why fogging and evaporative cooling follows the constant enthalpy (energy) line labeled ‘Fogger or Evaporative.’

Plotting Coolerado cooling and evaporative cooling on the same chart demonstrates that the Coolerado Cooler produces roughly twice the air density under these conditions.

Twice the air density represents roughly twice the power gain. Instead of a 3 to 15 percent gain in output, 6 to 25 percent can be expected with a Coolerado Cooler.

There is more cooling potential if wanted. What Coolerado rejects as waste is nearly saturated air a few degrees warmer than what the evaporative or fogging system produces as product. Use this cool, moist air for the compressor inter cooler or generator to boost efficiencies even higher.