Broc Energyfog - Fogging System For Gt

Gas turbine applications

Less fuel More power Lower emissions

Gas turbines represent a

Basic principles

significant and increasing

Gas Turbines are mass flow devices. In general terms, the higher the compressor mass flow the greater the power output capacity from the gas turbine. The mass flow to the compressor is a direct function of the air temperature.

share of thermal power generation plants worldwide. Although gas turbines are generally considered the most cost-effective and relatively environment-friendly large scale power generation technology, their capacity as well as their thermal efficiency degrades under high ambient temperature conditions. This lost capacity is often replaced by less efficient plants, which in turn amplifies even more the extra costs of power generation and CO2 emissions.

Cooling the inlet air increases its density, improving compressor mass flow and thus allowing the turbine to operate at a higher capacity. The end result is better efficiency, with higher electricity generation and reduced emissions. System power demand typically peaks during the hottest period of the day. This coincides with the periods when gas turbine generators in the system are at their lowest capacity. Adiabatic cooling allows the turbines to run close to their maximum potential capacity by reducing variations in their output due to the ambient temperature increase. Installed in the air inlet tract, EnergyFog achieves adiabatic cooling by injecting water through special atomizing nozzles producing a fog of very fine droplets which evaporate almost instantaneously. The evaporation process results in a cooling effect on the inlet air feeding the compressor. The air can nominally be cooled to the corresponding wet bulb temperature. Air inlet fogging also reduces NOx emissions and CO2 emission rates.

EnergyFog provides the most cost-effective technique to recover this lost gas turbine capacity through adiabatic cooling of

6 AM: Ambient temperature 20°C Without fogging: Power output 125MW

the gas turbine inlet air.

● Enhance performance

3 PM: Ambient temperature 30°C Without fogging: Power output 115MW

● Increase efficiency ● Improve fuel economy ● Cut emissions

3 PM Ambient temperature 30°C With fogging: Power output 127MW

Nozzle and optimum droplet size

Predictive control

The EnergyFog patented system design includes a nozzle producing optimum droplet size at less than 100 bars operating pressure. This low atomizing pressure results in

Most fogging systems operate through a predictive control loop which estimates, from ambient conditions, the quantity of water to be injected in the air inlet to reach water saturation and then sets this level with no feedback from the results.

• longer life of components • low auxiliary load consumption • improved operational control • reduced maintenance cost. EnergyFog’s nozzle produces a Sauter mean drop diameter of D32 of 15 microns or less, ideal for complete evaporation and effective cooling.

The graph shows the cumulative percentage of droplets of a given diameter (0-50 microns) produced at different nozzle pressures. Over a pressure range of 80 to 150 bars, more than 90% of the droplets produced by the nozzle measure less than 25 microns. Absence of large droplets is key to efficient cooling, complete evaporation and minimum water usage. EnergyFog Systems has long-term and ongoing research and development programmes and nozzle performance certification in cooperation with Politecnico Milano.

Who benefits? The benefits of fogging apply in most locations. Use of the technology is not limited to hot and dry conditions. Most sites’ ambient conditions allow sufficient potential for fogging systems to achieve simple payback in their first year of operation. With an investment cost of less than USD 50 per kilowatt of additional capacity, gas turbine inlet fogging represents the most cost-effective power enhancement technology. Installation time can be as little as 3 days enabling units to be fitted during scheduled outage, with no impact on the generation plan.

EnergyFog’s proprietary control system allows reliable direct measurement and control of the actual relative humidity of the air at the compressor inlet, and feeds this signal back to the controller, which compares it to the predictive result. This system allows detailed and optimum control of the fogging rate, ensuring automatic detection and correction in the event of excessive fogging. Because other fogging systems use multiple fixedvolume pumps which operate in a finite number of stages, they will usually fall short of optimum saturation or risk over-saturation and droplet carry-over. EnergyFog variable speed control pumps allow fine control of the water quantity injected and most effective cooling. EnergyFog Systems are manufactured to ISO quality standards.

Case study 1: Europe site Power €50 to €60/MWh Gas €4.5/GJ Engine GE 9E Potential ([Dry Bulb°-Wet Bulb°] x hours) = 15 000 degree.hours 12 000 MWhr incremental generation Net benefits €65 000 to €130 000 Savings on heat rate €80 000

Payback <12 months Case study 2: Middle East site Power €40/MWh Gas €2/GJ Engine GE 6B Potential ([Dry Bulb°– Wet Bulb°] x hours) = 35 000 degree.hours 9 000 MWhr incremental generation Net benefits >€160 000 Savings on heat rate €30 000

Payback <6 months

EnergyFog Systems combines the technical and innovation expertise of Edoardo Lossa in the air treatment and humidification industry with Marubeni’s experience and operations as an EPC contractor and global Independent Power Producer to provide gas turbine users with state of the art power industry specific fogging systems for enhanced power output and reduced emissions.

100 years of industrial and power industry experience applied to gas turbine fogging technology

Founded in 1870, Edoardo Lossa SpA brings over 100 years’ experience in industrial air treatment and humidification plants, with over 200 Lossatex units installed in more than 20 countries. Today, the company’s particular expertise in clean-room and textile industry air treatment brings innovative technology to the power generation sector.

Founded in 1858, Marubeni Corporation has far-reaching experience in international business operations with more than 130 offices in 73 countries. With extensive knowledge of the power industry – as an EPC contractor with more than 64,000 MW aggregate capacity supplied worldwide, and as an Independent Power Producer with 12,100 MW capacity in operation or under construction – Marubeni is well placed to address the specific power industry issues arising from the introduction of new and innovative technologies to the sector. Marubeni has, through its affiliate Wayarch Holdings, specifically focused on the introduction of new technologies, such as EnergyFog, to the power sector as a means of increasing the utilization rate of existing assets, raising generation efficiency standards and reducing emissions.

Gryphon Technologies 9 rue des Suisses 92380 Garches France Telephone + 33 1 47 95 55 76 Fax + 33 1 47 95 49 86 E-mail: [email protected] www.energyfog.com