Browsing by Author "Wang, Chih-Cheng"

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Design and Implementation of Intelligent Surge Controller for Modern Turbo Charged Automobiles
(2014-06-01)
Wang, Chi-Hsu
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Wang, Chih-Cheng
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電機工程學系
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電控工程研究所
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Department of Electrical and Computer Engineering
The destructive surge transient response is an expected phenomenon on a turbo charged automobile. Therefore a new intelligent controller to prevent the surge phenomenon to prolong the life cycle of modern turbo charged automobiles is proposed in this paper. In order to do so, the surge boundary for a particular turbo charger in a specific automobile must be determined first. A new systematic way without performing a real experiment to find the surge boundary is therefore proposed in this paper. The modeling of the turbo charged system is first discussed with Moore-Greitzer model with the new finding of determining the Helmholtz frequencies on the compressor load curves (CLCs) on the compressor map diagram. By substituting the real physical parameters of SAAB NG 900 into the modeling equation, the manufacturer\'s surge boundary and real surge boundary for all turbo charged automobiles can be accurately verified. These new results are immediately adopted in this paper to design an intelligent surge controller to minimize the risk of surge phenomenon in a turbo charger automobile. This new intelligent surge controller has the capability to maintain a certain pressure to bypass the surge boundary with minimum pressure release. Excellent real-time experimental results have been obtained to validate that our new approach is very effective. This will have decent applications in modern turbo charged intelligent automobiles.
Development of simultaneous partial nitrification, anammox and denitrification (SNAD) process in a sequential batch reactor
(2011-05-01)
Lan, Chien-Ju
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Kumar, Mathava
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Wang, Chih-Cheng
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Lin, Jih-Gaw
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環境工程研究所
Simultaneous partial nitrification, anammox and denitrification (SNAD) process was developed in a sequential batch reactor (SBR) and the influence of hydraulic retention time (HRT) on the SNAD process was investigated. Around 96% NH(4)(+)-N removal and 87% COD removal were observed at 9 d HRT. Marginal decreases in the removal efficiencies were observed when the HRT was reduced to 3 d or the loading rate was increased by three times. On the other hand, a drastic decrease in NH(4)(+)-N and COD removals were observed when the DO, pH and temperature were dropped shockingly. The response of the SNAD system towards the shock in substrate loading and operating conditions was evaluated by sensitivity index. Finally, the extent of total nitrogen (TN) removal by partial nitrification with anammox and denitrification was modeled using stoichiometric relationship. Modeling results indicated a TN removal of 85-87% by anammox with partial nitrification and 7-9% by denitrification. (C) 2010 Elsevier Ltd. All rights reserved.
Fast start-up, performance and microbial community in a pilot-scale anammox reactor seeded with exotic mature granules
(2011-02-01)
Ni, Shou-Qing
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Gao, Bao-Yu
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Wang, Chih-Cheng
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Lin, Jih-Gaw
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Sung, Shihwu
The possibility to introduce the exotic anammox sludge to seed the pilot-scale anammox granular reactor and its fast start-up for treating high nitrogen concentration wastewater were evaluated in this study. The reactor was started up successfully in two weeks; in addition, high nitrogen removal was achieved for a long period. Stoichiometry molar ratios of nitrite conversion and nitrate production to ammonium conversion were calculated to be 1.26 +/- 0.02:1 and 0.26 +/- 0.01:1, respectively. The Stover-Kincannon model which was first applied in granular anammox process indicated that the granular anammox reactor possessed high nitrogen removal potential of 27.8 kg/m(3)/d. The anammox granules in the reactor were characterized via microscope observation and fluorescence in situ hybridization technique. Moreover, the microbial community of the granules was quantified to be composed of 91.4-92.4% anammox bacteria by real-time polymerase chain reaction. This pilot study can elucidate further information for industrial granular anammox application. (C) 2010 Elsevier Ltd. All rights reserved.
Finding the Real Surge Boundaries of Turbo-charged Automobiles Using Intelligent Fuzzy Reasoning Technique
(2015-06-01)
Wang, Chi-Hsu
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Wang, Chih-Cheng
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資訊工程學系
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Department of Computer Science
Engine with turbo charger needs to be aware of the potential damage caused by surge phenomena. The focus of this paper is to propose a new intelligent reasoning to find the real surge boundary for a turbo-charged automobile without performing real complicated automobile experiment. Four physical fuzzy variables of a turbo-charged automobile, i.e., throttle size, pressure ratio, engine displacement, and total effective pipe length between the throttle and turbo charger, are chosen as the input to our intelligent reasoning algorithm system to produce the mass air flow for correction. The mass air flow for correction can then be applied on the compressor map of turbo charger to determine the real surge boundary for a certain turbo-charged automobile. In comparison with the previous approach using quadratic interpolation formula for exact real surge boundary, our new approach can indeed produce nearly the same answer with simplified computation load. Excellent benchmark tests are conducted on Saab NG 900 and 9000 with turbo chargers, Garrett T25-60.
Landfill-leachate treatment by simultaneous partial nitrification, anammox and denitrification (SNAD) process
(2011-08-01)
Wang, Chih-Cheng
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Kumar, Mathava
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Lan, Chien-Ju
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Lin, Jih-Gaw
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環境工程研究所
Simultaneous partial nitrification, anammox and denitrification (SNAD) process was developed in a sequential batch reactor (SBR), and the application of SNAD process for landfill-leachate treatment was investigated. The SNAD process was developed from the biomass of a full-scale landfill-leachate treatment plant. After the adaptation of biomass, the SBR was operated in four stages (I-IV) with varying nitrogen loading rates (NLRs), i.e. 118-280 mg-N/L/d, and organic loading rates (OLRs), i.e. 100-200 mg/L/d. The increase in the NLR has proportionately reduced the NH(4)(+)-N removal. However, the NO(2)(-)-N concentration was close to zero and the NO(3)(-)-N concentration was less than 36 mg/L in all the stages. A consistent chemical oxygen demand (COD) removal was observed in stages I to IV, which indicate that the SBR was not affected by the increase or decrease of the OLR. The total nitrogen removal in the SBR was mainly achieved by partial nitrification and anammox (69-88%) that was evaluated by a stoichiometric model. Moreover, the influence of NLR and OLR on the SNAD process was determined based on sensitivity index (SI). The SI values indicate that the SNAD process was highly affected by the influent NH(4)(+)-N compared to COD.
Process for treating nitrogenous wastewater with simultaneous autotrophic denitrification, hetertrophic denitrification and COD removal
(2011-04-14)
Lee, Der-Ming
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Chiang, Ming-Kuei
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Chen, Chin-Te
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Sung, Keng-Chuan
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Lin, Jih-Gaw
A process for treating nitrogenous wastewater contains an autotrophic denitrification reaction, a heterotrophic denitrification reaction and a COD removal reaction simultaneously and mixedly taking place in a single reactor. The nitrification reaction is caused by nitrifying bacteria, in which ammonium is oxidized into nitrite. The autotrophic denitrification reaction is caused by autotrophic denitrifying bacteria, in which ammonium used as electron donor and nitrite used as electron acceptor are converted into nitrogen gas and nitrate. The heterotrophic denitrification reaction is caused by heterotrophic denitrifying bacteria, in which nitrate and COD are consumed. It is not necessary to build two separate reactors for aerobic nitrification and anaerobic denitrification, thereby effectively reducing the fabrication and operation cost.
Simultaneous partial nitrification, anaerobic ammonium oxidation and denitrification (SNAD) in a full-scale landfill-leachate treatment plant
(2010-03-15)
Wang, Chih-Cheng
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Lee, Po-Heng
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Kumar, Mathava
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Huang, Yu-Tzu
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Sung, Shihwu
The occurrence of simultaneous partial nitrification, anaerobic ammonium oxidation and denitrification (SNAD) observed in a single Partially aerated full-scale bioreactor treating landfill-leachate is reported in his paper. At present, the full-scale bioreactor is treating an average leachate flow of 304 m(3) d(-1) with a sludge retention time between 12 and 18 d. The average COD, NH(4)(+)-N and NO(3)(-)-N concentrations at the upstream end of the bioreactor. i.e., influent, are 554, 634 and 3 mg L(-1), respectively; whereas no NO(2)(-)-N is detected in the influent. The percentage removals of COD and NH(4)(+)-N in the bioreactor were 28% and 80%, respectively. A nitrogen mass balance approach was adopted to analyze the performance of SNAD in the full-scale bioreactor. The total nitrogen (TN) removal by combined partial nitrification and anaerobic ammonium oxidation is 68% and the heterotrophic denitrification contributes to 8% and 23% of TN and COD removals, respectively. The red granule in the bioreactor was analyzed by using fluorescence in situ hybridization and polymerase chain reaction. The results of both analytical methods confirm the presence of anaerobic ammonium oxidizing bacteria as the predominant species along with other Planctomycete-like bacteria. Overall, the SNAD process offers the simultaneous removals of nitrogen and COD in the wastewater. (C) 2009 Elsevier B.V. All rights reserved.