Advanced

Investigation of different valve geometries and valve timing strategies and their effect on regenerative efficiency for a pneumatic hybrid with variable valve actuation

Trajkovic, Sasa LU ; Tunestål, Per LU and Johansson, Bengt LU (2008) SAE International Powertrains, Fuels & Lubricants Congress In SAE Technical Paper Series
Abstract
In the study presented in this paper a single-cylinder Scania D12 diesel engine has been converted to work as a pneumatic hybrid. During pneumatic hybrid operation, the engine can be used as a 2-stroke compressor for generation of compressed air during vehicle deceleration and during vehicle acceleration the engine can be operated as an air-motor driven by the previously stored pressurized air.



The compressed air is stored in a pressure tank connected to one of the inlet ports. One of the engine inlet valves has been modified to work as a tank valve in order to control the pressurized air flow to and from the pressure tank.



In order to switch between different modes of engine operation there is a need... (More)
In the study presented in this paper a single-cylinder Scania D12 diesel engine has been converted to work as a pneumatic hybrid. During pneumatic hybrid operation, the engine can be used as a 2-stroke compressor for generation of compressed air during vehicle deceleration and during vehicle acceleration the engine can be operated as an air-motor driven by the previously stored pressurized air.



The compressed air is stored in a pressure tank connected to one of the inlet ports. One of the engine inlet valves has been modified to work as a tank valve in order to control the pressurized air flow to and from the pressure tank.



In order to switch between different modes of engine operation there is a need for a VVT system and the engine used in this study is equipped with pneumatic valve actuators that uses compressed air in order to drive the valves and the motion of the valves are controlled by a combination of electronics and hydraulics.



This paper describes the introduction of new tank valve geometry to the system with the intent to increase the pneumatic hybrid regenerative efficiency. The new tank valve has a larger valve head diameter than the previously used setup described in order to decrease the pressure drop over the tank valve. In order to ensure tank valve operation during high in-cylinder pressures the valve is combined with an in-house developed pneumatic valve spring which makes the tank valve pressure compensated.



A comparison between the old and the new tank valve geometry and their effect on the pneumatic hybrid efficiency has been done. Also, optimization of the valve timings for both CM (Compressor Mode) and AM (Air-motor Mode) has been done in order to achieve further improvements on regenerative efficiency. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
subject
keywords
pneumatic hybrid vehicle, combustion engine, air hybrid vehicle, pressurized air, variable valve train, variable valve timing, hybrid, pneuamtic
in
SAE Technical Paper Series
publisher
Society of Automotive Engineers
conference name
SAE International Powertrains, Fuels & Lubricants Congress
external identifiers
  • other:SAE Technical Paper 2008-01-1715
ISSN
0148-7191
language
English
LU publication?
yes
id
7a092e12-c81a-48fa-aee1-6b0bafa20838 (old id 1215847)
alternative location
http://www.sae.org/technical/papers/2008-01-1715
date added to LUP
2008-08-15 14:22:25
date last changed
2016-04-15 23:50:54
@inproceedings{7a092e12-c81a-48fa-aee1-6b0bafa20838,
  abstract     = {In the study presented in this paper a single-cylinder Scania D12 diesel engine has been converted to work as a pneumatic hybrid. During pneumatic hybrid operation, the engine can be used as a 2-stroke compressor for generation of compressed air during vehicle deceleration and during vehicle acceleration the engine can be operated as an air-motor driven by the previously stored pressurized air.<br/><br>
<br/><br>
The compressed air is stored in a pressure tank connected to one of the inlet ports. One of the engine inlet valves has been modified to work as a tank valve in order to control the pressurized air flow to and from the pressure tank.<br/><br>
<br/><br>
In order to switch between different modes of engine operation there is a need for a VVT system and the engine used in this study is equipped with pneumatic valve actuators that uses compressed air in order to drive the valves and the motion of the valves are controlled by a combination of electronics and hydraulics.<br/><br>
<br/><br>
This paper describes the introduction of new tank valve geometry to the system with the intent to increase the pneumatic hybrid regenerative efficiency. The new tank valve has a larger valve head diameter than the previously used setup described in order to decrease the pressure drop over the tank valve. In order to ensure tank valve operation during high in-cylinder pressures the valve is combined with an in-house developed pneumatic valve spring which makes the tank valve pressure compensated.<br/><br>
<br/><br>
A comparison between the old and the new tank valve geometry and their effect on the pneumatic hybrid efficiency has been done. Also, optimization of the valve timings for both CM (Compressor Mode) and AM (Air-motor Mode) has been done in order to achieve further improvements on regenerative efficiency.},
  author       = {Trajkovic, Sasa and Tunestål, Per and Johansson, Bengt},
  booktitle    = {SAE Technical Paper Series},
  issn         = {0148-7191},
  keyword      = {pneumatic hybrid vehicle,combustion engine,air hybrid vehicle,pressurized air,variable valve train,variable valve timing,hybrid,pneuamtic},
  language     = {eng},
  publisher    = {Society of Automotive Engineers},
  title        = {Investigation of different valve geometries and valve timing strategies and their effect on regenerative efficiency for a pneumatic hybrid with variable valve actuation},
  year         = {2008},
}