電熱式與相變化儲熱式觸媒轉化器應用於機車冷啟動之污染排放改善探討

Electrically heated and PCM heat storing catalytic converters separately on the exhaust emission of motorcycle in the cold-start condition

謝旭峰(Shiu-Feng Hsieh)

指導教授 ： 洪榮芳

共同指導教授 ： 張育斌

崑山科技大學/工程學院/機械工程研究所/碩士(2010年)

https://doi.org/10.6828/KSU.2010.00007

摘要

機車引擎冷啟動期間需啟動增濃裝置，供應較濃的空燃比以啟動引擎。另觸媒轉化器在此時亦未達反應溫度，而造成大量的污染排放。
本研究自行設計兩組機車冷啟動污染改善裝置，分別為電熱式觸媒轉化器以及儲熱式觸媒轉化器。其中電熱式觸媒轉化器將加熱塞裝置於新、舊排氣管並搭配不同加熱位置、不同加熱溫度以及不同行車速度再進行實驗測試後，以掃描式電子顯微鏡 (Scanning Electron Microscopy, SEM)拍攝新舊、觸媒轉化器表面形貌並以能量散射光譜儀(Energy Dispersive Spectrometer, EDS)進行觸媒轉化器之表面成分分析。而儲熱式觸媒轉化器則首先以加熱爐對相變化儲熱材料加熱後，取出冷置於室溫環境，以了解其基本特性後，再以不同行車速度與冷置時間搭配各比例之相變化儲熱材料進行實驗測試。
裝設電熱式觸媒轉化器後，冷車啟動怠速測試時，提供加熱能量能使排氣管溫度迅速提升，提早達到轉化溫度，新排氣管CO、HC 之污染排放改善率約可達43.25%與51.01%，舊排氣管CO、HC 之污染排放改善率約可達65.06%與76.8%。但在定速行駛時，未燃氣氧化釋放大量熱量，使觸媒轉化器溫度能迅速提升，並達到轉化溫度，因此在提供加熱能量後CO與HC污染改善率約2%與3%左右，其污染排放改善效果相當有限。
加裝儲熱式觸媒轉化器後，錫鋅比例15:85(wt%)有較佳之儲熱效果，在冷置1小時後，在各行車速度CO與HC污染改善率約可達20%。而在冷置2小時後，其CO與HC污染改善率亦可達約10%。

關鍵字

觸媒轉化器 ； 冷啟動 ； 錫鋅比例

並列摘要

The intake mixture of motorcycle engine was enriched in the cold-start conditions. The severe exhaust emissions of motorcycle were emitted in the cold start because the catalyst did not reach the light-off temperature. This study designed the electrically heated and PCM (Phase change material) heat storing catalytic converters separately for improving exhaust emissions of motorcycle under cold-start.
In the electrically heated catalytic converters, the electrical heaters were installed in the new and used catalytic converters separately. They were tested under various heating positions, heating temperatures and driving speeds. Further, the photos of the new and used catalyst surfaces were taken by the scanning electron microscope (SEM) for comparison, and the surface elements of the catalyst were analyzed by the energy dispersive spectrometer (EDS) simultaneously.
As for the PCM catalyst, before installation in the exhaust pipe, the experiments for melting and solidifying behaviors of PCM were conducted to build the data bank for future applications. After the testing, various proportions of PCM were put in the exhaust pipes of motorcycle and experimented under different driving speeds and cold-socking time.
The results were obtained as follows. For the electrically heated catalytic converters, it could pre-heat the catalyst and speed up the rising of the catalyst temperature in idle test. The improvements of CO and HC emissions were 43.25% and 51.01% respectively for the new exhaust pipe; and CO and HC improvements were 65.06% and 76.8% respectively for used exhaust pipe. However, in the driving test, the improvements in CO and HC emissions were not obvious. They were about 2% and 3% approximately.
For the PCM catalytic converters, Tin-Zinc ratio of 15:85 (wt%) had a better effect of heat storage. With 1-hour cold socking, the improvement of CO and HC exhaust emissions was about 20%; and the improvement was down to about 10% with 2-hour cold socking.

並列關鍵字

Catalytic Converter ； cold start ； Tin-Zinc ratio

參考文獻

[3]R.F. Horng, “Effect of input energy on the cold start characteristics of an EHC with heat storing material on a motorcycle engine,” Energy Conversion & Management, 46 (2005) pp. 1043-1057.

[4]R.F. Horng, H.M. Chou, “Effect of input energy on the emission of a motorcycle engine with an electrically heated catalyst in cold-start conditions,” Applied Thermal Engineering, 24 (2004) pp. 2017-2028.

[5]R.F. Horng, H.M. Chou, T.C. Hsu, “Effect of heating energy and heating position on the conversion characteristics of a four-stroke motorcycle engine in cold start conditions, ”Energy Conversion and Management, 45(2004) pp. 2113-2126.

[6]N. Kishi, S. Kikuchi, H. Kaiho, T. Hayashi, “The research of zero level emission vehicle using gasoline: effient method for using the hybrid catalyst and EHC,” JSAE Review, 21(2000) pp. 9-14.

[8]R. Joumard, M. Andre, R. Vidon, P. Tassel, C. Pruvost, “Influence of driving cycles on unit emissions from passenger cars,” Atmospheric Environment, 34(2000)pp. 4621-4628.