Supercharged expander to enhance waste heat recovery through ORC unit in vehicle applications Universita degli Studi dell Aquila

Format:

Book

Conference/Event

Author/Creator:

Di Battista, Davide, author.

Contributor:

Cipollone, Roberto

DI BARTOLOMEO, Marco

Fatigati, Fabio

Conference Name:

15th International Conference on Engines & Vehicles (2021-09-12 : Capri, Italy)

Language:

English

Physical Description:

1 online resource cm

Place of Publication:

Warrendale, PA SAE International 2021

Summary:

Waste Heat Recovery is one of the major opportunities to increase the engine efficiency in internal combustion engines for transportation sector and to meet the emissions targets. ORC-based unit are widely investigated, in particular for heavy duty vehicles and light commercial ones. However, when a typical operation of the ICE on a vehicle is considered, working temperature and exhaust flow rates are not always suitable for recovery, being characterized by low-grade enthalpy. Volumetric expanders are among the most suitable technological solutions for small scale ORC-based power units, but they can suffer of low efficiency in real operation. A way to improve its performances is represented by a supercharging technique, which involves a further intake portrait Indeed, keeping constant the mass flow rate provided by the pump, the dual-intake expander produces a reduction of the intake pressure with a mechanical power similar to the single intake machine. The machine, in fact, is more permeable and this reduces, for a given flow rate, the upstream expander pressure with a beneficial effect in terms of operating conditions. This aspect can enhance the expander operability in off design conditions, which is particularly interesting when the hot source is represented by the exhaust gases of an Internal Combustion Engine (ICE). In fact, the mass flow rate circulating inside the ORC unit can increase, in order to recover more thermal power. If the dual intake expander is used, a higher mass flow rate can be elaborated with respect to the single-intake port, keeping constant the intake pressure. In this paper, a combined theoretical and experimental activity has been done, reproducing real ICE operation in a small-scale ORC test bench fed by exhaust gases of a 3L turbocharged diesel engine and prototyping the supercharged expander. In this way, the benefits related to the additional port are assessed in real engine working points, compared to the single port one and introducing further developing paths

Notes:

Vendor supplied data

Publisher Number:

2021-24-0092

Access Restriction:

Restricted for use by site license