The importance of air filtration in reciprocating engine power

In the world of reciprocating engine power generation air intake combustion filtration and air ventilation filtration can play a significant role to improve operational performance.

Air Filtration has a significant impact on engine performance, especially in protecting the turbocharger and aftercooler systems from debris ingress and fouling. Damage to the turbocharger and/or the aftercooler is often the first indication that an air intake filtration system or the filtration efficiency are not suitable for a given application.

In this article we will evaluate the need for air filtration and how the quality of the surrounding air and the changing dynamics in the engine market play a role in determining the type of filtration required. Air filtration should be considered as a function of the total mass of contaminant ingested which is directly influenced by the type of atmospheric and industrial environment i.e. the ambient air quality of a given installation.

Air contamination can be caused by natural plant matter or solid particulate found in the air. It can also be caused by man-made air pollution hazards. Understanding the air quality challenges of a given location or installation can help determine the optimum air filtration solution to enhance engine performance. Let’s start by exploring the key air quality challenges that can impact engine performance.

Understanding the air quality challenges

• Industrial – In the industrial and urban environment, air quality can be particularly low with a high concentration of particles from energy production, vehicle traffic, industrial process, building construction and demolition projects.

• High dust – In desert, arid, and dry environments high concentrations of dust particles are the greatest challenge, especially in areas susceptible to sandstorms and where particles can stay suspended in the air for many hours.

• Sustained Moisture – Prolonged free moisture results in particles swelling on the outer surface of the air filters. This results in the formation of a ‘cake’ around the filter that cannot be easily removed, even with reverse pulse cleaning. This leads to an increase in pressure drop.

• Rural – In rural and agricultural environments airborne contamination is often seasonal, including pollen, seeds, and insects. A pollen season is determined by the surrounding trees and plants and may result in a very high volume of airborne particulate. Farming also creates high concentrations of dust in the plow season.

• Coastal – In coastal environments sustained high humidity and the removal of salt are the greatest challenges. Salt is prevalent as both a dry particulate and as an aerosol, it is typically found in high concentrations due to the prevailing wind picking up sea spray from the waves.

• Extreme heat – Extreme heat is a common problem in engine halls. This is controlled through ventilation, but this still needs to be filtered air with a suitable silencer to help with overall noise mitigation. In certain climates ventilation is not enough and an air-cooling solution is required such as an evaporative cooler.

• Snow & Ice – In sub-zero climates snow and ice are the biggest hazards, often covering the outer surface of the filter elements and significantly reducing the airflow. This in turn causes high pressure drop, resulting in power output deterioration.

Changing market conditions

The significance of air filtration for reciprocating engine power generation is gaining an increased awareness as operators are evaluating how to decarbonise operations. OEMs are also developing market-leading technologies and starting to implement hybrid power plants (solar or wind combined with gas engines). Today, flexible engine power plants can use 100% synthetic and carbon-neutral methane and methanol fuel. They are also capable of using hydrogen/natural gas blends containing up to 25% hydrogen – and a pure hydrogen solution is in the pipeline.

The use of gas and alternative fuels and the drive to decarbonize will lead to an increase of the filtration efficiency required. In comparison to diesel / heavy fuel oil (HFO) gas an alternative fuel source is clean with stable properties and therefore the quality of the air becomes more significant on the performance of the engine. These developments will have an impact on air filtration requirements.

The outcome

The individual location of a reciprocating engine installation is fundamental to determine the individual air quality challenge. There are many factors that influence air quality both man-made and natural and so a thorough understanding of the surrounding environment is important to understand the potential impact of low cost and low quality air filtration could have on engine performance.

Operators are faced with a choice to implement a low cost filtration solution or the optimum filtration solution for their given installation. Optimized air filtration will meet the individual air quality challenges of a given installation and in doing so will protect engines, especially turbochargers and aftercoolers. It will also lead to reduced downtime, lower maintenance costs and a more efficient operation.

An Operator should consider the commercial and environmental benefits of improved air filtration. There is no ‘one size fits all’ approach to engine air filtration but the impacts of poor filtration can be very costly, inefficient and lead to increased emissions and environmental impact.

To understand more contact AAF for further support.