Einstein's theory of relativity fundamentally asserts the conservation of matter, implying that matter is not destroyed but rather transformed. Applying this principle to the combustion process within a kinetic engine, such as an internal combustion engine, unveils that oxygen, being a form of matter, does not get burnt or obliterated as commonly perceived. Instead, it undergoes a transformation from one form of matter to another during combustion.
In the engine's operation, the intake valve opens, allowing the combustion chamber to fill with a mixture of air and fuel. Given that atmospheric air comprises various gases, with oxygen constituting approximately 21%, this mixture enters the combustion chamber. Through compression and subsequent ignition, this air-fuel mixture undergoes combustion, leading to the transformation of oxygen and fuel into several gases, primarily CO (carbon monoxide), CO2 (carbon dioxide), H2O (water vapor), and NOx (nitrogen oxides).
The proportions of these gases in the exhaust provide insights into the combustion process. Typically, CO, O2, and CO2 constitute the primary focus, amounting to approximately 16% of the initial oxygen intake of 21%. Notably, NOx and H2O, though present, are often disregarded due to their minimal impact or inability to be measured directly.
Whether the air-fuel mixture is rich or lean, the collective percentage of CO, O2, and CO2 remains relatively constant at around 16%. Deviations from this norm, such as exhaust leaks, Air Injection malfunctions, and misfires, can indicate underlying issues within the engine or exhaust system. when the number exceeds 16%
Here are the revised examples:
Rich: HC 200PPM, CO 3.2%, O2 0.01%, CO2 12.8%
Lean: HC 200PPM, CO 0.01%, O2 3.2%, CO2 12.8%
In both scenarios, the sum of the three gases in the triangle remains at 16%.
For instance, a scenario involving a rich-running engine failing a smog test elucidates the practical application of the exhaust gas triangle theory. Elevated O2 levels, contrary to expectations in a rich condition, suggest additional air entering the exhaust. Investigation reveals a malfunctioning air injection system, which disrupts the combustion process, leading to skewed exhaust gas proportions.
Moreover, misfiring cylinders introduce unconverted oxygen into the exhaust, exceeding the expected 16% threshold. Similarly, air injection system malfunctions or exhaust leaks permit additional oxygen to dilute the exhaust gases, altering the CO, O2, and CO2 ratios.
Notably, CO2 serves as a crucial indicator of engine efficiency, typically reaching around 15.5% in optimal conditions. However, misfires disrupt combustion, causing a drop in CO2 levels due to oxygen dilution. Consequently, understanding and analyzing exhaust gas proportions provide valuable diagnostic insights into engine performance and potential malfunctions.
