Exergy Analysis in Internal Combustion Engine Systems

Exergy analysis applies the second law of thermodynamics to quantify the maximum useful work potential of energy flows within internal combustion engines and to pinpoint irreversibilities that degrade performance. Unlike conventional energy analysis, which considers only quantity, exergy assessment evaluates both the quantity and quality of energy, offering deeper insight into combustion inefficiencies, heat transfer losses, frictional dissipation and exhaust energy losses. By constructing energy and exergy balances around the combustion chamber, cooling system and exhaust line, researchers can identify major sources of exergy destruction and target design modifications or control strategies to minimise losses. Practical applications encompass optimisation of compression ratio, injection timing and charge composition, as well as the development of advanced low‐heat‐rejection engines and thermoelectric recovery systems. Exergy methods have also been instrumental in assessing the performance of alternative fuels—such as biodiesel, syngas, ammonia blends and nanoparticle-enhanced fuels—by comparing their exergetic efficiencies and destruction profiles. Globally, exergy analysis underpins efforts to reduce carbon footprint, improve fuel economy and guide policy on sustainable transport. The continued integration of experimental measurements, one-dimensional simulations and computational fluid dynamics promises to refine exergy diagnostics and enable next-generation engine architectures with higher second-law efficiencies.

Research from Nature Portfolio

No recent Nature Portfolio content available.

Exergy Analysis in Internal Combustion Engine Systems publication trend

The graph below shows the total number of articles in exergy analysis in internal combustion engine systems across all publications each year (not limited to Nature Index journals).

Technical terms

Exergy: The maximum useful work that can be extracted from an energy flow as it reaches equilibrium with its environment.

Exergy destruction: The irreversible loss of work potential in a system, often arising from entropy generation during processes such as combustion and heat transfer.

Exergetic efficiency: The ratio of useful work output to exergy input, reflecting the second-law performance of a device or process.

Entropy generation: A measure of irreversibility within a thermodynamic system, indicating the degree to which energy degrades in quality.

References

1. Energy-Exergy Analysis of Diesel Engine Fueled with Microalgae Biodiesel-Diesel Blend. Applied Sciences (2023).
2. Energy, exergy and sustainability analyses of nanoparticles added to fuels to reduce carbon footprint. Case Studies in Thermal Engineering (2024).
3. Experimental based comparative exergy analysis of a spark‐ignition Honda GX270 Genset engine fueled with LPG and syngas. Energy Science & Engineering (2022).