Complete Guide to MeeFog’s Fogging Systems for Gas Turbines

Overview: Power Augmentation for Gas Turbines

Gas turbines are rated at ISO conditions (15°C/59°F and 60% relative humidity), but peak power demand typically occurs at much higher ambient temperatures. As temperatures rise to 105°F (40°C), air density drops, reducing mass flow and cutting turbine output by roughly 15-20%.

Installing a MeeFog system for gas turbines allows you to recover a significant part of the lost output by injecting high-pressure demineralized water into the inlet air supply to the gas turbine. This water evaporates quickly and cools the air. Cooler air is denser, so the output of the gas turbine is increased.

Many facilities have recovered a significant portion of lost output with fog cooling. Using a MeeFog system for gas turbines, a Sahara Power Station managed to improve the output of the gas turbines by as much as 15%, while using half the water that water injection in the combustor would require.

The Physics of Evaporative Cooling

Fogging relies on the fast evaporation of fine water droplets. When the fogging system injects water into the air stream, heat from the air is absorbed by the droplets. As they evaporate, the surrounding air cools rapidly: this is direct, efficient evaporative cooling. Only demineralized water is used to avoid fouling, scaling, or corrosion, a non-negotiable for long-term operation.

Wet Compression: Beyond Evaporative Cooling

While air inlet fogging delivers strong results, some facilities need even greater power and flexibility. MeeFog fogging systems can also operate in a wet compression mode (also known as overspray or intercooling). Here, water droplets are added in amounts beyond what the ambient air can absorb before the compressor. This “overspray” finds a different path to higher performance.

How Wet Compression Works

• Droplet Size and Injection: The fogging system sprays sub-10-micron droplets directly into the compressor inlet. These particles are small enough to survive the trip and evaporate inside the compressor’s compression stages.
• Thermodynamic Effect: As the droplets vaporize within the compressor, they provide “intercooling.” This reduces the temperature rise caused by compression and lowers the work the compressor must perform.
• Performance Gain: By lowering compressor work, there is more energy available for power output. Wet compression can add more output by 5–15% beyond that gained from evaporative cooling alone.

Practical Considerations

Gas turbine wet compression operates best when the control system tightly manages flow rates based on ambient conditions. Outlet temperature, humidity, and compressor design all affect how much additional water may be safely and effectively added. Mee Industries has developed proprietary controls and advanced impaction-pin nozzle technology to deliver reliable, erosion-free operation with these demanding configurations.

Technical Specifications and System Design

Over 50 years of active research and field experience have shaped the current MeeFog fogging system for gas turbines. We build every system with the “most important thing” in mind: safe, efficient power improvement that lasts.

• Operating Pressure: The system uses 2,000 psi (138 bar) to generate a true fog of sub-10-micron droplets. This is essential because lower pressures create larger drops, which evaporate less efficiently and may lead to water fallout or pooling.
• Droplet Size: Droplets consistently measure below 10 microns Sauter Mean Diameter (SMD). Fast evaporation is the goal. Reliable sizing eliminates the risk of blade erosion or system deposits.
• Nozzle and Materials: MeeFog nozzles feature 316 stainless steel with laser-drilled orifices and fixed impaction pins. Stainless steel resists corrosion and metal fatigue. Impaction pins improve fog quality and extend service life.
• Lifespan: Proper water treatment is key. When fed high-purity demineralized water, MeeFog nozzles can operate for over 30 years with proper water treatment.
• Filtration: Pump skids safeguard the system with 0.35-micron inlet filters and 10-micron discharge filters. This removes particulates that could impair the fog pattern or damage nozzle manifolds.

System Integration and Maintenance

Careful system integration is necessary. Placement of manifolds, droplet trajectory, control logic, and feedback from turbine instrumentation all keep your fogging system working safely and efficiently. Routine maintenance involves verifying filter state, checking pump performance, inspecting nozzles, and reviewing water purity logs.

Support Services for Fogging Systems

Your fogging system’s long life and performance hinge on attention to detail beyond initial installation. Since the company’s start, Mee Industries has made comprehensive support a core value. We commit not just to the system, but to client education and operational confidence.

Support services include:

• Functional testing of pumps, VFDs, and control logic
• Nozzle flow verification and pattern validation
• Coordination with turbine OEM representatives (if required)
• Operator training and handover documentation
• Nozzle inspection and refurbishing (if required due to water quality issues)
• Pump skid routine maintenance
• Control system tuning for optimized performance
• Performance verification and reporting

Gas Turbine Compatibility and Fogging System References

MeeFog technology is compatible with all major gas turbine OEMs. Since launching our first gas turbine fogging system in 1994, we have covered over 1,200 installations and 90 gigawatts (GW) in operating capacity. This includes large and small power plants, industrial cogeneration, and grid-balancing peaking stations across the United States and internationally. Our compatibility extends to:

• GE, Siemens, Mitsubishi, and Alstom turbines
• Combined cycle configurations
• 300 MW Power output
• Challenging locations such as offshore platforms and high ambient environments

Selected Installation Profiles

The following table provides an overview of MeeFog installations for gas turbines worldwide, focusing on different OEMs, locations, and operational environments.