化工学报
化工學報
화공학보
JOURNAL OF CHEMICAL INDUSY AND ENGINEERING (CHINA)
2015年
5期
1656-1666
,共11页
刘剀%陆海峰%郭晓镭%刘一%潘响明%龚欣
劉剴%陸海峰%郭曉鐳%劉一%潘響明%龔訢
류개%륙해봉%곽효뢰%류일%반향명%공흔
文丘里管%燃料%两相流%压差%气力输送
文丘裏管%燃料%兩相流%壓差%氣力輸送
문구리관%연료%량상류%압차%기력수송
Venturi%fuel%two-phase flow%pressure drop%pneumatic conveying
研究粉煤密相气力输送系统高压、高浓度煤粉通过不同节流比(0.44、0.55、0.7)、收缩角(2.5°、5°、9°)、扩张角(2.5°、8°、13°)、喉段长度(23d、43d、80d)的文丘里管的流动特征和压差特性。结果表明,不同结构参数的文丘里管的量纲1化压力分布趋势一致,但程度不一。其中节流比影响最为显著,并最直接地影响煤粉流经文丘里管的压差。节流比越小,总压差越大,扩张段压差显著增大。其他结构参数在各自的结构序列下主要改变文丘里管内压力分布,而对总压差改变不大。2.5°收缩角的收缩段压差最大,高浓度体系下5°和9°收缩角的收缩段压差差别不大。80d 喉段长度的喉段压差最大。8°扩张角的扩张段压差最小。引入固相动量通量,获得本系统内煤粉流经文丘里管的压降经验方程,大部分实验点的计算偏差在30%以内,方程计算效果较好。
研究粉煤密相氣力輸送繫統高壓、高濃度煤粉通過不同節流比(0.44、0.55、0.7)、收縮角(2.5°、5°、9°)、擴張角(2.5°、8°、13°)、喉段長度(23d、43d、80d)的文丘裏管的流動特徵和壓差特性。結果錶明,不同結構參數的文丘裏管的量綱1化壓力分佈趨勢一緻,但程度不一。其中節流比影響最為顯著,併最直接地影響煤粉流經文丘裏管的壓差。節流比越小,總壓差越大,擴張段壓差顯著增大。其他結構參數在各自的結構序列下主要改變文丘裏管內壓力分佈,而對總壓差改變不大。2.5°收縮角的收縮段壓差最大,高濃度體繫下5°和9°收縮角的收縮段壓差差彆不大。80d 喉段長度的喉段壓差最大。8°擴張角的擴張段壓差最小。引入固相動量通量,穫得本繫統內煤粉流經文丘裏管的壓降經驗方程,大部分實驗點的計算偏差在30%以內,方程計算效果較好。
연구분매밀상기력수송계통고압、고농도매분통과불동절류비(0.44、0.55、0.7)、수축각(2.5°、5°、9°)、확장각(2.5°、8°、13°)、후단장도(23d、43d、80d)적문구리관적류동특정화압차특성。결과표명,불동결구삼수적문구리관적량강1화압력분포추세일치,단정도불일。기중절류비영향최위현저,병최직접지영향매분류경문구리관적압차。절류비월소,총압차월대,확장단압차현저증대。기타결구삼수재각자적결구서렬하주요개변문구리관내압력분포,이대총압차개변불대。2.5°수축각적수축단압차최대,고농도체계하5°화9°수축각적수축단압차차별불대。80d 후단장도적후단압차최대。8°확장각적확장단압차최소。인입고상동량통량,획득본계통내매분류경문구리관적압강경험방정,대부분실험점적계산편차재30%이내,방정계산효과교호。
The flow characteristics and pressure drop of gas-coal mixtures under high pressure and concentration through a Venturi with different structures, including diameter ratio(0.44, 0.55, 0.7), convergence angle (2.5°, 5°, 9°), diffuser angle (2.5°, 8°, 13°) and throat length (23d,43d,80d) were investigated in the dense phase pneumatic conveying of pulverized coal system. A similar trend but a varied degree in non-dimensional pressure distribution for the gas-coal mixture through different Venturis was observed. The most remarkable influence parameter was diameter ratio, which had the greatest influence on pressure drop. The increase in pressure drop of the Venturi and remarkable increase in pressure drop in the diffuser were observed with the decrease of diameter ratio. The major role of other structural parameters was to change pressure distribution inside the Venturi, while having little influences on total pressure drop. The greatest convergence pressure drop for the convergence angle series occurred in the 2.5°. There was little difference of convergence pressure drop between 5° and 9° under high pressure and concentration. The greatest throat pressure drop for the throat length series occurred in the 80d. The least diffuser pressure drop for the diffuser angle series occurred in the 8°. By introducing solids momentum flux,an empirical equation of pressure drop of gas-coal mixture through the Venturi was established. It showed good prediction with deviations from most experimental value within 30%.