5 things about Gas Turbine Inlet Air Cooling (GTIAC) you need to know

GTIAC is a cost-effective optimised solution.

Today, there are various ways to enhancethe power output of gas turbines. Themost cost-effective means is Gas TurbineInlet Air Cooling (GTIAC). This technologycan increase a gas turbine generator’soutput to produce 30%+ more electricityat a fraction of the cost of a new gasturbine generator.

The most consistently successful methodof GTIAC is mechanical cooling. Based onproven water-chiller and heat-exchangertechnologies, this method delivers the
cooling capacity, dependably andconsistently to obtain optimal output fromthe gas turbine. Operating the turbine atthe relatively constant conditions offered
by mechanical cooling can improveturbine life and lower maintenance costs.

Five important things aboutGas Turbine Inlet Air Cooling (GTIAC) you need to know:

1. Selectingintake temperature

For GTIAC, a commonly considered bell mouthintake air temperature is 15oC. This may not bethe optimal intake temperature for all GTIACinstallations. In locations with high humidity,you need to consider the level of “sensible”cooling that is economically optimal. Otherwise,chiller capacity will be used in condensing thewater vapor in the air.

2. Determiningdesign point

When selecting a design point for GTIAC,it is important to remember that relativehumidity (RH) and ambient temperatureare counter cyclical. The RH at anylocation drops with an increase in ambientdry bulb temperature and vice versa.If the design set point is selected basedon the highest RH and highest dry bulbtemperature at a location, it would resultin a vastly oversized chilling plant.

3. Choosingchilling coil

Optimal chilling coil design is crucial. If the chilling coil sizein the filter house is too small, the chilled water temperaturerequired to achieve the desired inlet air temperature wouldbe low and the chilled water delta T would be small.To produce this chilled water at lower temperatureand small delta T, a larger capacity chiller plant is required,with higher than necessary parasitic load.

4. Configuringmultiple chillers

Connecting multiple chillers in seriescounter flow configuration has a significantimpact on system efficiency. This typeof cascading configuration can reduce
the compressor work needed by eachchiller, improving the overall chiller systemefficiency by as much as 8%.

5. Designingholistically

In many projects, the scope of supply responsibilityfor chiller plant and coils lies with separate vendors.This results in a GTIAC system that does not haveoptimal lifetime performance. It is vital to takea holistic approach to GTIAC system designfrom the start.