Cooling method for gas turbines in Remote Areas

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Containerized turbines are a cost-effective, expedient way to install quality equipment. These turbines are ready to go on delivery, including all mechanical, electrical, and control components. These units are compact and easily serviced making them ideal for many applications, both temporary and permanent. Containerized turbines offer many advantages for remote projects or those with a short timeline. Many turbine installations, especially in warm climates, feature less-than-desirable efficiency. Have you been wondering how to improve the operation of your turbines in remote areas? Find out how in this post.

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Turbine Inlet Air Cooling - TIAC

Turbine Inlet Air Cooling (TIAC) is a method that cools the inlet air to the turbines resulting in power output augmentation and increased efficiency. This technology is used to boost the production and efficiency of gas turbines by lowering the temperature of the air going into the turbine through evaporative cooling or by an inlet chiller. TIAC systems are available containerized or skid mounted and delivered to remote locations to allow isolated plants, new and existing, to take advantage of the benefits. Most times, one unit can serve a bank of turbines; occasionally, a unit dedicated to one or more turbines is required to enhance power and boost efficiency. TIAC systems achieve improved environmental emissions. 

Below we compare Evaporative Cooling and Inlet Chiller methods for better turbine power output and efficiency.

 

TIAC with Evaporative Cooling

Evaporative coolers provide a beneficial, cost-effective, and environmentally-sound way of cooling air. These systems blow the intake air through or across a wet media, cooling the air as it absorbs moisture. Evaporative coolers with the highest wetted surface area and sufficient airflow achieve the best results. Rejection of evaporative cooling may occur when an external water source is not readily available or when restrictions on water use exist.

These systems use significantly less electricity than other options; therefore, they are a frequent consideration when water is available. Evaporative cooling may also provide a benefit in areas where there is considerable particulate matter in the air. Particulate matter damages turbines and other equipment, evaporative coolers filter the air well and may help prevent damage from particulate matter. The simple design of evaporative coolers makes them easy to install, operate, and maintain, making them cost-effective, efficient, and hassle-free. Evaporative coolers do not require refrigerants and do not pose a risk to safety or the environment, which is another critical advantage.

Although evaporative coolers are beneficial in many regions of the world, in humid regions, where the air is already moisture-laden, an evaporative cooler cannot work effectively. These systems are typically low maintenance; however, the pads or media needs to remain wet to allow the air to absorb moisture. When pads dry out, the system is less efficient; drying can occur rapidly in warm, dry climates. Fouling may occur in areas with a lot of suspended dust in the air. Algae growth and mineral build-up can be problematic with evaporative cooling as well. Evaporative cooling requires high-quality source water, regular replacement of the media, water monitoring, and treatment may also be necessary for proper operation of the evaporative chiller.

 

TIAC with Inlet Air Chilling

Inlet chillers or coolers include a basic heat exchanger with a solution or some other way to reject heat. These chillers use a chemical refrigerant and the compression cycle to chill the solution. The chilled solution is pumped through the heat exchanger; in this case, the turbine inlet, absorbing heat from the air entering the turbines. There are two main types of condensers used with these types of chillers, water-cooled or air-cooled.

Each type of condenser has its unique advantages and disadvantages. Chiefly, a water-cooled condenser may work better when the gap in temperature between the ambient air and the discharge air is small. Similarly, an air-cooled condenser may be a better choice when water is scarce or when regulations exist regarding water use. Water-cooled condensers require a natural cold-water source, such as seawater, or a cooling tower.

The compression cycle of refrigeration occurs in a closed system and depends on a pressure change for the change in temperature to occur; therefore, it is sensitive to leaks. The chemicals typically used for refrigerants in these chillers may pose a safety and environmental threat, a consideration when selecting a chiller and refrigerant.

Inlet coolers are a very robust, efficient solution requiring little maintenance. These benefits make inlet chillers an ideal solution for many gas turbine installations.

 

Why TIAC?

Installing a TIAC system produces additional “hidden” MW of power at a rate cheaper than would be possible with an additional turbine. Therefore, we often add them to existing systems to increase power output, especially during peak temperatures, which can often coincide with peak demands. TIAC increases the power output of existing gas turbines at a cost less than that of an additional turbine. TIAC systems offer the operator a tremendous amount of flexibility. They can dial in the system to allow a specific output, efficiency, or a combination of the two. This flexibility can be especially helpful at a remote site where power demands vary from day to night or even day-to-day. The flexibility also allows operators to achieve maximum power output when the demand is high but still achieve the most efficient operation possible at all times.

Manufacturing and shipping a TIAC system to a location often occurs more quickly than the manufacture and shipping of an additional gas turbine, yet another advantage to considering TIAC when additional power is needed. TIAC systems virtually eliminate any weather-related risks and allow for greater predictability of emissions. Control of emissions continues to become increasingly important around the world as we consider what these gases are doing to the earth’s atmosphere and the resulting climate changes. Owners of gas turbines with TIAC systems also report lower operations and maintenance costs, another tremendous benefit.

 

Other Considerations

With ARANER, the design for the TIAC system includes a comprehensive analysis of local temperature and dewpoint fluctuations, as well as the fluctuations in demand on a daily and yearly basis. It is also worthwhile to consider any other climatic or other factors that may ultimately affect the life of the gas turbine and TIAC systems, such as minerals in water and sand or other impurities in the air. The installation of added filtration systems can help to prevent unintended damages to the turbines and the TIAC system itself.

 

Conclusion

If your containerized gas turbine facility isn’t operating at its full design potential because of stale, warm intake air, contact ARANER today. Our staff of professionals can assist you with a TIAC facility that will boost production and increase overall efficiency. We can help you achieve up to 30% more capacity and potentially double existing efficiency. If you want to learn more about Turbine Inlet Air Cooling systems, download the e-book below.