Thermodynamic and Practical Benefits of Waste Energy Recovery Using an Electric Turbo-Generator Under Different Boosting Methods University of Michigan

Format:

Conference/Event

Author/Creator:

Kiwan, Kiwan, author.

Contributor:

Middleton, Robert

Stefanopoulou, Anna

Conference Name:

WCX World Congress Experience (2018-04-10 : Detroit, Michigan, United States)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2018

Summary:

AbstractThis paper provides insight into the tradeoffs between exhaust energy recovery and increased pumping losses from the flow restriction of the electric turbo-generator (eTG) assessed using thermodynamic principles and with a detailed GT-Power engine model. The GT-Power engine model with a positive displacement expander model was used to predict the influence of back pressure on in-cylinder residuals and combustion. The eTG is assessed for two boosting arrangements: a conventional turbocharger (TC) and an electrically assisted variable speed (EAVS) supercharger (SC). Both a low pressure (post-turbine) and high pressure (pre-turbine) eTG are considered for the turbocharged configuration. The reduction in fuel consumption (FC) possible over various drive cycles is estimated based on the steady-state efficiency of frequently visited operating points assuming all recovered energy can be reused at an engine efficiency of 30% with 10% losses in the electrical path. On the city FTP and US06 cycles, the EAVS SC engine benefits more than the turbocharged from adding the eTG. The opposite is observed for the highway cycle where adding the eTG causes greater fuel consumption reductions for the turbocharged engine. Boost reserve in the TC case at low load, however, makes the EAVS SC with eTG (boost-by-wire) a better boosting and energy recovery system overall with reductions in FC up to 1.4%, 2.4% and 4.6% relative to the TC engine over the FTP, highway and US06 cycles respectively

Notes:

Vendor supplied data

Publisher Number:

2018-01-0851

Access Restriction:

Restricted for use by site license