天津大学学报
天津大學學報
천진대학학보
JOURNAL OF TIANJIN UNIVERSITY SCIENCE AND TECHNOLOGY
2014年
1期
1-8
,共8页
舒歌群%许晓菲%田华%贾琦%孙秀秀%刘丽娜
舒歌群%許曉菲%田華%賈琦%孫秀秀%劉麗娜
서가군%허효비%전화%가기%손수수%류려나
柴油机%多品位余热%低 (火用)损%跨临界有机朗肯循环%联合循环
柴油機%多品位餘熱%低 (火用)損%跨臨界有機朗肯循環%聯閤循環
시유궤%다품위여열%저 (화용)손%과림계유궤랑긍순배%연합순배
diesel engine%multiple grades waste heat%low exergy destruction%transcritical organic Rankine cycle%combined cycle
为了提高柴油机多品位、大温差余热的回收利用率,提出了一种低(火用)损跨临界有机朗肯联合循环,其中高温级循环用于回收温度较高的柴油机排气余热和废气再循环(EGR)余热,低温级循环回收柴油机冷却水余热、增压空气余热、与高温级循环换热后的排气余热和 EGR 余热.高温级对比分析了3种硅氧烷工质 MM、MDM 和 D4,低温级选用了 R143a,模拟研究了高低温级参数对循环性能的影响.结果表明:高低温级均存在最优的蒸发压力,高温级冷凝压力在允许范围内越低越好;高温级采用 MM 较 MDM 和 D4循环性能更好,循环净功最高可以达到36.36,kW,(火用)损只有4.5,kW;各部分余热的利用率均在86%以上;增加高低温级的回热效能均可以提高循环性能.
為瞭提高柴油機多品位、大溫差餘熱的迴收利用率,提齣瞭一種低(火用)損跨臨界有機朗肯聯閤循環,其中高溫級循環用于迴收溫度較高的柴油機排氣餘熱和廢氣再循環(EGR)餘熱,低溫級循環迴收柴油機冷卻水餘熱、增壓空氣餘熱、與高溫級循環換熱後的排氣餘熱和 EGR 餘熱.高溫級對比分析瞭3種硅氧烷工質 MM、MDM 和 D4,低溫級選用瞭 R143a,模擬研究瞭高低溫級參數對循環性能的影響.結果錶明:高低溫級均存在最優的蒸髮壓力,高溫級冷凝壓力在允許範圍內越低越好;高溫級採用 MM 較 MDM 和 D4循環性能更好,循環淨功最高可以達到36.36,kW,(火用)損隻有4.5,kW;各部分餘熱的利用率均在86%以上;增加高低溫級的迴熱效能均可以提高循環性能.
위료제고시유궤다품위、대온차여열적회수이용솔,제출료일충저(화용)손과림계유궤랑긍연합순배,기중고온급순배용우회수온도교고적시유궤배기여열화폐기재순배(EGR)여열,저온급순배회수시유궤냉각수여열、증압공기여열、여고온급순배환열후적배기여열화 EGR 여열.고온급대비분석료3충규양완공질 MM、MDM 화 D4,저온급선용료 R143a,모의연구료고저온급삼수대순배성능적영향.결과표명:고저온급균존재최우적증발압력,고온급냉응압력재윤허범위내월저월호;고온급채용 MM 교 MDM 화 D4순배성능경호,순배정공최고가이체도36.36,kW,(화용)손지유4.5,kW;각부분여열적이용솔균재86%이상;증가고저온급적회열효능균가이제고순배성능.
Diesel engine has multiple grades waste heat with large temperature difference. In order to improve the efficiency of waste heat recovery,a transcritical combined organic Rankine cycle with low exergy destruction is pre-sented. High-temperature stage cycle recovers high grades waste heat including exhaust and exhaust gas recircula-tion(EGR),while low-temperature stage cycle recovers low grades waste heat including cooling water,supercharged air,exhaust and EGR after rejecting heat at high-temperature stage cycle. Considering MM,MDM and D4 as the working fluid for high-temperature stage cycle,and R143a for low-temperature stage cycle,the effect of cycle pa-rameters is simulated and analyzed. The results show that both high-and low-temperature stage cycles have an optimal evaporating pressure,and high-temperature stage condensing pressure should be smaller within its allowable range. MM system has better performance than that using MDM and D4 with maximum net power being 36.36,kW and the exergy destruction being 4.5,kW. Each grade of waste heat recovery ratio is above 86%. Increasing the regenerator efficiency of both the high-and low-temperature stage can improve cycle performance.