Environmental Impact and Thermodynamics in Engine Emissions: A Comprehensive Guide

The environmental impact of engine emissions is a critical issue that has been the subject of extensive research. One approach to assessing this impact is through the use of exergy analysis, which involves the assessment of the maximum reversible work done by a system at constant temperature and pressure. This method can provide a comprehensive understanding of the environmental impact of engine emissions by considering the thermodynamic properties of the system.

Exergy Analysis and Environmental Metrics

Exergy analysis can be used to calculate various environmental and sustainability metrics, such as the ecological effect factor (EcoEF), environmental effect factor (EEF), exergetic sustainable index (ExSI), and sustainable efficiency factor (SEF). These metrics can provide valuable insights into the environmental impact of engine emissions and help identify potential areas for improvement.

Ecological Effect Factor (EcoEF)

The EcoEF is calculated from exergy efficiency and provides an indication of the engine’s environmental impact. It is a dimensionless quantity that ranges from 0 to 1, with a value closer to 1 indicating a lower environmental impact.

Environmental Effect Factor (EEF)

The EEF is the ratio of fuel exergy waste ratio to exergy efficiency and provides an indication of the engine’s environmental impact. A lower EEF value indicates a lower environmental impact.

Exergetic Sustainable Index (ExSI)

The ExSI is found from the environmental effect factor and provides an indication of the engine’s sustainability. A higher ExSI value indicates a more sustainable engine.

Sustainable Efficiency Factor (SEF)

The SEF is calculated from exergy efficiency and provides an indication of the engine’s sustainability. A higher SEF value indicates a more sustainable engine.

Specific Irreversibility Production (SIP)

The SIP is the ratio of total exergy destruction to the net thrust of the engine and provides an indication of the engine’s sustainability. A lower SIP value indicates a more sustainable engine.

Case Studies

environmental impact and thermodynamics in engine emissions

A study of a kerosene-fuelled high by-pass turbofan (HBP-TF) engine found that the ExSI and SEF increased with higher turbine inlet temperature (TIT) and higher high-pressure compressor pressure ratio (HPC-PR), indicating improved engine sustainability. The study also found that SIP decreased as TIT and HPC-PR increased, further indicating improved engine sustainability.

Another study used exergy analysis to assess the environmental impact of a turbofan engine under different design conditions. The results showed that the engine’s environmental impact varied depending on the design conditions, with some conditions leading to lower environmental impact than others. The study also found that the use of metaheuristic methods for multi-objective optimization of entropy-based and exergy-based metrics could help identify optimum design variables for sustainable engine operation.

Predicting Thermodynamic Parameters with Deep Learning

Exergy analysis can also be used to predict thermodynamic parameters of an engine with deep learning approaches, considering flight and design conditions. This approach can provide valuable insights into the engine’s performance and help identify potential areas for improvement.

DIY Environmental Impact and Thermodynamics Assessment

To assess the environmental impact and thermodynamics of engine emissions, individuals can perform the following steps:

  1. Collect data: Collect data on the engine’s performance, including fuel consumption, exhaust gas temperature, and pressure differences across the engine.
  2. Perform exergy analysis: Use exergy analysis to calculate the various environmental and sustainability metrics, such as EcoEF, EEF, ExSI, SEF, and SIP.
  3. EcoEF can be calculated as: EcoEF = 1 – (Fuel exergy waste ratio / Exergy efficiency)
  4. EEF can be calculated as: EEF = Fuel exergy waste ratio / Exergy efficiency
  5. ExSI can be calculated as: ExSI = 1 / EEF
  6. SEF can be calculated as: SEF = Exergy efficiency
  7. SIP can be calculated as: SIP = Total exergy destruction / Net thrust
  8. Analyze results: Analyze the results to identify potential areas for improvement in the engine’s performance and sustainability.
  9. For example, if the SIP value is high, it indicates a high level of irreversibility in the engine, which can be addressed by optimizing the engine design or operating conditions.
  10. Implement changes: Implement changes to the engine’s design or operation to improve its environmental impact and sustainability.
  11. This could involve adjusting the TIT, HPC-PR, or other design parameters to improve the engine’s sustainability metrics.

By following these steps, individuals can assess the environmental impact and thermodynamics of engine emissions and take steps to improve the engine’s performance and sustainability.

References

  1. Aygun, H., Sheikhi, M. R., Caliskan, H., Thermodynamics, Environmental and Sustainability Impacts of a Turbofan Engine Under Different Design Conditions Considering Variable Needs in the Aviation Industry. Global Challenges 2024, 8, 2300205.
  2. Rosen, M. A. (2002). Assessing energy technologies and environmental impacts with the principles of thermodynamics. Applied Energy, 72(3), 427-441.
  3. Elfasakhany, A., Tola, S. (2021). Impact of microalgae biofuel on microgas turbine aviation engine: a combustion and emission study. Fuel, 302, 121155.
  4. Dinc, A., Gharbia, Y. (2020). Exergy analysis of a turboprop engine at different flight altitude and speeds using novel consideration. International Journal of Turbo Jet-Engines, doi: 10.1515/tjeng-2020-0017.
  5. Dinc, A., Sohret, Y., Ekici, S. (2022). Thermodynamic-based environmental and enviroeconomic assessments of a turboprop engine used for freight aircrafts. Journal of Thermal Analysis and Calorimetry, 147, 12693–12707.