Caldwell Wet Compression Technology (CWCT)

Quick Facts

  • Increase Energy output up to 25%
  • Only technology with consistent power gains regardless of ambient conditions
  • Costs less per installed KW than any other Inlet Cooling Technology
  • Complimentary to PowerChill®, PowerStor® and PowerFog®


Caldwell Wet Compression Technology (CWCT) is the next step to increasing output and efficiency of combustion turbines. Output on most turbines is targeted at a 15% increase with an improvement in heat rate of 1.5%. Since the improvement in the heat rate is across the total output of the combustion turbine (CT), the incremental heat rate improvement is 11.5%. The following table illustrates CWCT performance effects on a 100 MW Frame Class Turbine operating in simple cycle.

How it Works

There are basically three effects produced by the injection of fog into the bellmouth region of a combustion turbine. They are:

  1. Reduction of inlet air temperature to near wet bulb temperature
  2. Mass flow enhancement augmenting power output
  3. Increased efficiency of the compressor, resulting in output increase and improved efficiency


Caldwell Wet Compression Technology stands poised to revolutionize power augmentation technology. CWCT systems properly inject micron sized fog droplets into the compressor section of the CT. These are not upsized fogging systems. CWCT systems typically inject four times the amount of water that a fogging system does into a cross-sectional area one-eighth the size. In order to achieve this, a very robust nozzle rack with multi-orifice nozzle holders are used to achieve the required flow with minimum droplet size. The high pressure water supply is generated by industrial grade positive displacement pumps with maintenance intervals similar to combustion turbines. Typical mass flow injection rates are equal to 2% of the air flow at ISO conditions, similar to the flow rates of NOx water injection systems. To minimize the effect of thermal stresses on a combustion turbine, the spray flow is staged up and down during startup and shutdown of the system in an engineered manner. Many other safety features are incorporated into the system to protect both the turbine and the CWCT system.