A feasibility study of the new concept exhaust gas recirculation (EGR) system for low carbon vehicles

Lead Research Organisation: Brunel University
Department Name: Sch of Engineering and Design

Abstract

In recognition of the need to further reduce vehicle exhaust emissions and the greenhouse effect of CO2, there has been a lot of interest in developing cleaner and more efficient energy saving vehicle powertrain. In Europe, this has been enforced by the recently introduced European legislation of CO2 emissions of 130g/km by 2015, and the proposal to reduce it to less than 100g/km by 2020 and further reduction beyond. In response to the social, legislative and environmental pressures, there is a large body of engine research work demonstrating the large energy saving and emissions reducing benefits of using higher and higher quantities of exhaust gas recirculation (EGR). To meet the needs of the these new generation of low emission and high efficiency IC engines, future demand for EGR would be in the order of 40% to 80% to cover the operational range of highly boosted gasoline and diesel engines operating in both conventional (SI, CI) and new (HCCI/CAI) combustion modes. However, this will be far beyond the capability of the present day EGR systems and has prompted the need for new research activities to improve the system and deliver more EGR focused. In the proposal, a new EGR system has been put forward on the basis of needs from industry and developed from first principles. The new concept EGR system has the potential to work in harmony with the engine boost system, bridging the EGR technology gap caused by the awkward partnership of previous systems. All the new technologies, including the highly boosted diesel and gasoline engines, downsizing, and HCCI/CAI combustion could be achieved with the new concept EGR and further improved and extended. This represents a paradigm shift in the availability of boosted EGR in the next generation energy saving IC engines, hence the importance and timeliness of this project. The proposed research is based on the applicants' world leading experience in a wide range of engine research areas. It will be the first time that a new EGR system is examined on the basis of needs from industry and developed from first principles. Successful outcomes from this project could lead to extensive collaboration with industrial partners, exploiting many new uses of boosted EGR so that the most cost-effective emissions and energy saving control methods could be developed and eventually incorporated into future engines and production vehicles.

Planned Impact

In recognition of the need to further reduce vehicle exhaust emissions and the greenhouse effect of CO2, there has been a lot of interest in developing cleaner and more efficient energy saving vehicle powertrain. In Europe, this has been enforced by the recently introduced European legislation of CO2 emissions of 130g/km by 2015, and the proposal to reduce it to less than 100g/km by 2020 and further reduction beyond. Boosted EGR is the generic concept underlying many recent advanced IC engine developments. The capability of providing boosted EGR freely and effortlessly will significantly accelerate progress in the next generation clean and high efficiency diesel and gasoline engines for low carbon vehicles. The proposed work is to carry out a proof-of-concept for Rotex EGR, and confirm its potential of bridging the EGR technology gap. The new concept EGR system could lead to new advances and expansion of many diverse engine research areas, with Rotex EGR serving as the enabling technology for developing new frontier energy saving engines. The direct beneficiary will be automotive OEMs who will be able to use the results to develop their next generation low carbon vehicles. The successful mass production of the new engines with Rotex EGR will in turn provide significant environmental and economic benefits to the community at large due to improved fuel economy and substantially lower CO2 emissions. Based on 10% improvement in fuel consumption of the new engine, for every 100,000 new cars sold each year, it is equivalent to a saving of 6 million litres of fuel in the first year, and the annual fuel economy will increase as the number of these new cars on the road increases. In Climate Change terms, this is equivalent to 16,000 tonnes CO2 saving in the first year. The results will be presented to the relevant automotive OEMs and Tier 1 suppliers in UK and Europe through visits and emails. The results of the proposed project will also be published in the open literature and presented at UnICEG meetings, which are free and attended by a large number of delegates from industry and academic institutions. The outcome of the research project will also be featured on the group's Web page and the novel EGR technology can also be presented to the public through science and technology awareness activities organised by EPSRC and other government organisations. Furthermore, since Brunel University was a core member of the Network Of Excellence in ECO-Engines within the EU FP6 programme which comprises 24 top research institutions and companies across Europe engaged in engine research, the information can be disseminated directly to members of the ECO-Engines. The overall aim of the proposed research is to bridge the EGR technology gap and bring about a paradigm shift in the availability and use of EGR in the next generation advanced IC engines. It is envisaged that the innovative concept proposed for boosted EGR shall be researched and developed in three stages. Stage 1: the feasibility study to demonstrate the functionality of the Rotex EGR system, Stage 2: its first use in a passenger car diesel engine through a TSB research programme to be setup with an automotive OEM for verification of the Rotex EGR system, Stage 3: the general use of Rotex EGR through future TSB and industrial collaboration programmes extending the boundaries of engine research.

Publications

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Description A feasibility study was carried out on a new type of device that could be used to recirculate the burned gases more effectively to reduce the emission of internal combustion engines.
Exploitation Route The results demonstrated that it is possible to supply the exhaust gas with the new device but it will require additional mechanical drive and will be sensitive to engine speed. Thus, its implementation may prove difficult.
Sectors Aerospace, Defence and Marine,Energy,Transport

 
Title A pressurised mixed flow rig 
Description In order to study the flow and mixing characteristics of two compressed gas streams in a flow device, a pressurized mixed flow rig as designed and built. The compressed air from a large compressor at 7 bar is split into two streams which are regulated separately to a desired pressure by two electronically controlled pressure regulators. The high pressure gas from a gas bottle is then supplied to one of the streams to simulate the exhaust gas of an engine and its composition is measured by a oxygen sensor. The flow rate of each individual streams of the gases of different composition and pressure are measured by two flow meters. The two gas flows are then supplied to the flow device to study the flow and mixing characteristics of the flow device. 
Type Of Material Improvements to research infrastructure 
Provided To Others? No  
Impact This rig has been used to the research of turbine design for an automotive turbocharger.