Bai S.-Z.,Weifu Lida Catalytic Converters Co. |
Lang S.-G.,Shandong University |
Lang S.-G.,Weifu Lida Catalytic Converters Co. |
Yuan K.-P.,Shandong University |
And 2 more authors.
Advanced Materials Research
Avoiding the urea deposition in the exhaust stream is one of the basic requirements for SCR system normal application. Unreasonable structure design, machining and installation position all could lead to urea crystallization on the wall of exhaust pipe and the front end surface of the catalyst, in addition, unreasonable control strategy also could deteriorate this phenomenon. The components of the urea depositions are the urea and cyanuric acid analyzed by thermogravimetry - FTIR technology. The integrated injector mounting is designed to alleviate the urea crystallization based on analysis results. The engine test and the vehicle road test are all shown that the optimal structural design and calibration strategies could avoid crystallization and sedimentation effectively in the exhaust system. © (2014) Trans Tech Publications, Switzerland. Source
Liu Y.,Shandong University |
Liu Y.,Weifu Lida Catalytic Converters Co. |
Sun L.,Weifu Lida Catalytic Converters Co. |
Bai S.-Z.,Shandong University |
And 4 more authors.
Neiranji Gongcheng/Chinese Internal Combustion Engine Engineering
An after-treatment study was conducted on a typical non-electronically controlled diesel engine using combined system of diesel oxidation catalyst (DOC)/particle oxidation catalyst (POC)/selective catalytic reduction catalyst (SCR) to attain China-V emissions standards. The research was focused on the selection and arrangement of treatment units. The experiments results show that employing DOC+POC or SCR system can only reduce either particulate matters (PM) or NOx to the China-V standards level, while adopting DOC/POC/SCR combined system can bring both PM and NOx emissions down to the China-V standards level. There is no obvious influence of different sequence arrangement of SCR and DOC+POC system on pollutants conversion efficiency. However, the passive regeneration of POC can be only fully achieved by placing DOC+POC before SCR system due to sufficient amount of NO2 in exhaust which can be utilized for PM oxidation, and such arrangement can reduce hydrothermal aging effect on SCR catalyst owing to lower inlet temperature. The backpressure of the combined system can be less than 25 kPa through the application of ceramic-based POC and optimal design of packaging structure. ©, 2015, Chinese Society for Internal Combustion Engines. All right reserved. Source