Turbo-expander cooling for NOX control in diesel engines


This report details the testing of an ACT turbo-expander on a high-speed Diesel engine to explore if NOX reduction can be achieved by turbo-expansion cooling. NOX reduction in Diesels is needed due to the detrimental environmental and health impacts it has across the globe. Testing was completed using a Ford 1.5 DuraTorq engine and a custom test cycle. The test cycle was developed to test the most used section of the engines rev range, whilst also overcoming oil cooling and low intake temperature issues. A NOX analyser failure meant that NOX emissions result could not be gathered. Exhaust temperatures were compared between the standard engine and turbo-expander equipped engine, as a decrease in exhaust temperatures would indicate a reduction in combustion temperature and therefore NOX emissions. 3 tests were carried out under each condition; the results were then analysed using a two-tailed T-test with a significance level of 0.05. The results showed that at an engine speed of 2500rpm or greater the reduction in exhaust temperature was statistically significant, with the largest reduction in exhaust temperature being 34.51°C at 2750rpm at 70% throttle. At low engine speeds the turbo-expander was showed to increase the exhaust temperature with the largest increase being 52.28°C at 2000rpm at 70% throttle. The turbo-expander was also proven to reduce engine power by an average of 1kW due the reduced intake pressure resulting from the frictional loses in the turbo-expander rotating assembly. If testing is repeated changes to the test setup must be made to make it more repeatable and to capture more data.  


Exhaust Temperature, Intake Temperature, Automotive, Diesel Engine, Turbo-Expander, Emissions, NOX

How to Cite

Draper L., (2021) “Turbo-expander cooling for NOX control in diesel engines”, Fields: journal of Huddersfield student research 7(1). doi: https://doi.org/10.5920/fields.820







Liam Draper (School of Computing and Engineering: Automotive and Motorsport Engineering)





Creative Commons Attribution 4.0


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