不同海拔下甲醇替代率和主喷正时对RCCI发动机性能的影响     

黄粉莲  佘超杰  万明定  杨仕臣  雷基林  申立忠 《农业工程学报》2024,40(5):71-81

为探究不同海拔条件下甲醇/柴油反应活性控制压燃（reactivity controlled compression ignition, RCCI）发动机的运行特性,该研究基于甲醇/柴油双燃料发动机试验台架,试验研究1 800r/min、100%负荷和3 200r/min、100%负荷下不同甲醇替代率、柴油喷射正时对发动机燃烧与排放性能的影响规律。结果表明：不同海拔条件下随着甲醇替代率的增加,缸压和瞬时放热率峰值逐渐升高,燃烧始点和燃烧中心前移,当量有效燃油消耗率（equivalent brake specific fuel consumption, ESFC）降低,有效热效率升高,NO_x和碳烟排放大幅降低,THC（total hydrocarbons）和CO排放增加。1 800 r/min、100%负荷工况下,甲醇替代率由0增至20%,0、1 000、2 000m海拔下最大缸压平均增加1.72MPa,瞬时放热率峰值平均升高25.08J/(°),ESFC平均降低4.67%,有效热效率平均升高4.90%,NO_x和碳烟排放分别平均降低16.63%和50%,THC和CO排放量分别平均增加142.03、388.18 mg/kg。3 200 r/min下甲醇替代率由0增至7%,不同海拔高度下ESFC平均降低1.76%,有效热效率平均升高1.79%,NO_x和碳烟排放量分别平均降低8.17%和20.70%。海拔高度由0升至2 000m,1 800r/min、20%甲醇替代率与3 200r/min、7%甲醇替代率下,瞬时放热率峰值分别降低4.80和8.08J/(°),燃烧中心分别推迟1.44°和1.43°,有效热效率分别降低0.82%和0.68%,ESFC分别升高2.10%和1.99%,NO_x排放量分别减少10.61%和7.35%,碳烟排放分别增加26.54%和32.12%,THC排放分别升高29.88%和15.45%,CO排放量分别增加22.42%和18.15%。固定甲醇替代率后,随着柴油主喷正时提前,不同海拔条件下缸压和放热率峰值逐渐升高,燃烧中心向上止点靠近,ESFC逐渐降低,有效热效率升高,碳烟排放减少,NO_x、THC和CO排放增加。1 800 r/min、15%甲醇替代率下,主喷正时从-1.5°提前至-7.5°,不同海拔高度下ESFC平均降低8.27%,有效热效率平均升高9.08%,碳烟排放平均减少90.94%。为提升高海拔条件下甲醇/柴油RCCI发动机的热效率和燃油经济性,可以适当增大柴油主喷正时。研究结果可为不同海拔环境下甲醇/柴油RCCI发动机燃烧与污染物排放控制优化提供参考。  相似文献   

Nutritional and feeding value of crude glycerin for poultry. 2. Evaluation of feeding crude glycerin to broilers     

《The Journal of Applied Poultry Research》2011,20(4):514-527

  相似文献   

柴油-甲醇-水复合乳化燃料的乳化工艺的试验     

王延遐  刘永启 《农机化研究》2005,(4):184-186

柴油-甲醇-水复合乳化燃料综合了柴油-水乳化燃料和柴油-甲醇乳化燃料两者的优点,日益引起了人们的注意。为此,介绍了两种制备柴油-甲醇-水复合乳化燃料工艺—CR-2型乳化装置法和电动机械搅拌法,并给出了相应的研究结果。  相似文献   

柴油机燃用甲醇/柴油双燃料的试验研究   总被引：1，自引：2，他引：1  

张军昌  师帅兵  张娟利 《拖拉机与农用运输车》2005,(4):45-47

对原柴油机基本不改变其结构和调整参数的基础上,实现了甲醇/柴油双燃料的简单改造并进行了试验研究。研究表明,双燃料发动机在甲醇吸入量在212~722.89g/h范围内时,发动机能平稳工作,发动机的动力性、经济性和排放性能均优于原柴油机。  相似文献   

发酵蓝莓酒品质影响因素及其解决方法     

王爱军  陆敏  郭意如 《保鲜与加工》2021,21(5):56-62

以"北陆"蓝莓为原料,研究果胶酶、护色单宁、酿酒酵母、二氧化硫和原酒冷冻浓缩对蓝莓酒品质的影响,探讨蓝莓酒中甲醇含量高、色素不稳定、有硫臭味、干浸出物含量低、感官品质差的解决方法,以提高蓝莓酒品质.结果表明,蓝莓果浆采用20 mg/L Clarification果胶酶酶解效果好,蓝莓酒中的甲醇含量低;采用浓缩汁发酵蓝莓酒,未检出甲醇,但原酒的典型性减弱;发酵前期加入500 mg/L护色单宁Tanin VR Supra,或陈酿期加入500 mg/L护色单宁Tanin VR Color,可有效提高蓝莓酒色素的稳定性;发酵结束后原酒中加入30 mg/L二氧化硫,既没有硫臭味,又能防止酒体氧化;8％原酒冷冻浓缩为10％原酒可提高干浸出物含量,增强其典型性;使用拉弗德F33酵母发酵酿造蓝莓酒,酒香浓郁,果香鲜明,酒体协调,蓝莓酒品质较优.  相似文献   

8个杧果品种胶乳挥发性成分及胶乳的灼伤机制初探     

母军霞  高兆银  弓德强  李敏  吴家礼  于婧  李俊国  胡美姣 《热带作物学报》2021,42(12):3625-3632

以‘台农1号’‘贵妃’‘金煌’‘玉文’‘红象牙’‘四季蜜杧’‘金穗’和‘红杉林’8个杧果品种的胶乳为材料,利用气相色谱–质谱联用技术对其挥发性成分进行测定,用NIST 11标准谱库对测定的质谱数据进行自动检索对照,保留匹配度大于90%的化合物,并对不同杧果品种的胶乳挥发性成分进行差异性分析,旨在为确定杧果胶乳中灼伤果皮的主要挥发性成分提供科学参考,并采用超景深三维显微镜观察果皮灼伤前后变化,为初步探索胶乳灼伤果皮机制提供参考。结果表明：（1）8个杧果品种共鉴定出30种匹配度大于90%的化合物,这些化合物分为萜烯类、酚类、醛类和烷烃类。其中,萜烯类是主要挥发性成分,酚类、醛类和烷烃类占比极少。8个杧果品种胶乳中共有的化合物有α-蒎烯、3-蒈烯、α-水芹烯、4-蒈烯、(R)-(+)-柠檬烯、桧烯、(1R)-(+)-α-蒎烯、萜品油烯、L-石竹烯和2,4-二叔丁基苯酚共10种。其中,3-蒈烯和萜品油烯为8个杧果品种胶乳的主要挥发性成分。（2）根据8个杧果品种胶乳中各挥发性成分的相对含量为数据源进行主成分分析将其分为5类：第一类为‘贵妃’和‘金煌’,第二类为‘台农1号’和‘四季蜜杧’,第三类为‘红象牙’和‘金穗’,第四类为‘玉文’,第五类为‘红杉林’。同一类别杧果品种其胶乳的主要挥发性成分及相对含量相似,不同类别杧果品种其胶乳的主要挥发性成分及相对含量差异较大。（3）杧果胶乳导致果皮皮孔褐变损伤,‘台农1号’接触胶乳的1 h后发生轻微灼伤,贵妃接触胶乳10 min时明显灼伤。研究结果明确了8个杧果品种乳胶中挥发性成分及其在不同品种中相对含量的差异,为揭示不同杧果品种胶乳灼伤果皮机制提供了基础。  相似文献   

恩拉霉素提取工艺研究     

闵江  梁景乐 《中国兽药杂志》2022,56(2):42-45

为优化恩拉霉素提取工艺,以70%甲醇溶液为提取剂,提取恩拉霉素,经过浓缩、脱色、结晶、重结晶,制备高含量恩拉霉素产品。得到最佳提取工艺条件是：浸提pH3.5~4.0,浸提温度30 ℃,三次浸提时间1 h,一次浸提料液比1∶7,二次浸提料液比1∶3,三次浸提料液比1∶3,活性炭用量是浓缩液体积的1.0%~1.5%,粗精粉重结晶得到纯品,含量97%。  相似文献   

Reaction behavior of lignin in supercritical methanol as studied with lignin model compounds   总被引：2，自引：0，他引：2  

E.?Minami  H.?Kawamoto  S.?SakaEmail author 《Journal of Wood Science》2003,49(2):158-165

 The reaction behavior and kinetics of lignin model compounds were studied in supercritical methanol with a batch-type supercritical biomass conversion system. Guaiacol, veratrole, 2,6-dimethoxyphenol, and 1,2,3-trimethoxybenzene were used as model compounds for aromatic rings in lignin. In addition, 5-5, β-1, β-O-4, and α-O-4 types of dimeric lignin model compounds were used as representatives of linkages in lignin. As a result, aromatic rings and 5-5 (biphenyl)-type structures were stable in supercritical methanol, and the β-1 linkage was not cleaved in the β-1-type structure but converted rapidly to stilbene. On the other hand, β-ether and α-ether linkages of β-O-4 and α-O-4 lignin model compounds were cleaved rapidly, and these compounds decomposed to some monomeric compounds. Phenolic compounds were found to be more reactive than nonphenolic compounds. These results indicate that cleavages of ether linkages mainly contribute to the depolymerization of lignin, whereas condensed linkages such as the 5-5 and β-1 types are not cleaved in supercritical methanol. Therefore, it is suggested that the supercritical methanol treatment effectively depolymerizes lignin into the lower-molecular-weight products as a methanol-soluble portion mainly by cleavage of the β-ether structure, which is the dominant linkage in lignin. Received: December 19, 2001 / Accepted: April 30, 2002 Acknowledgments This research has been done under the research program for the development of technologies for establishing an ecosystem based on recycling in rural villages for the twenty-first century from the Ministry of Agriculture, Forestry and Fisheries, Japan; by a Grant-in-Aid for Scientific Research (B)(2) (no.12460144, 2001.4–2003.3) from the Ministry of Education, Culture, Sports, Science and Technology, Japan; and under the research program from Kansai Research Foundation for Technology Promotion, Japan. The authors thank them for their financial support. This study was presented in part at the 45th Lignin Symposium, Ehime, Japan, October 2000 and the 52nd Annual Meeting of the Japan Wood Research Society, Gifu, Japan, April 2002 Correspondence to:S. Saka  相似文献   

Decomposition behavior of woody biomass in water-added supercritical methanol     

Eiji Minami  Shiro Saka 《Journal of Wood Science》2005,51(4):395-400

The chemical conversion of Japanese beech (Fagus crenata Blume) in water-added supercritical methanol was studied for a wide range of water content using a batch-type reaction vessel to obtain chemicals from lignocellulosics. It was consequently found that addition of water enhanced the decomposition of wood cell wall components; cellulose, hemicelluloses, and lignin. In cases of high water content, however, it resulted in low solubility of lignin-derived products causing an increase in the mass of the residue. The water content was thus optimized to be around 10% (v/v) for the decomposition of wood. Concomitantly, the yields and selectivity of the chemicals from wood could be regulated by the addition of water, especially for the lignin-derived products. As a result, the monomeric compounds of lignin, coniferyl alcohol and sinapyl alcohol, were recovered as their γ-methyl ethers in the presence of water in higher yields than those obtained without addition of water.  相似文献   

3种植物提取物对小麦茎秆性状、光合特性及产量的影响     

郑瑞明  周小云  李进  张军高  陈勇  马德英  梁晶  龚静云  雷斌 《新疆农业科学》2022,59(5):1068-1076

【目的】研究苦豆子(Sophraalopecuroides)、孜然(Cuminum cyminum)、苦草(Vallisneria natans)3种植物甲醇提取物对小麦的生长调节作用,为新型植物源生长调节剂的研制提供依据。【方法】选用春小麦品种新春44号为材料,以清水处理为对照,将苦豆子、孜然和苦草甲醇提取物浸膏分别制备成3种不同浓度(1%、0.1%、0.01%)的溶液,于小麦拔节前期连续喷施3次,分析小麦株高等茎秆性状、光合特性及产量等相关指标的影响;采用主成分分析法,筛选并评价植物提取物的生物活性。【结果】0.01%苦豆子甲醇提取物处理后,小麦基部第1、2、3节间长度分别降低27.8%、13.4%、4.5%;茎粗分别增加9.4%、16.1%、14.3%;基部3节IAA含量提高16.2%;基部3节ABA含量降低7.9%;株高降低5.6%;旗叶净光合速率增加3.9%;旗叶SPAD值增加6.2%;千粒重、籽粒重量、容重分别增加2.8%、24.7%和3.6%。0.01%苦豆子处理效果显著优于其他处理组。【结论】苦豆子、孜然和苦草3种低浓度甲醇提取物对小麦均具有不同程度的生长调控作用,能缩短节间长度和增加茎粗,增强小麦抗倒伏能力,降低小麦株高的作用,改善田间的通风透光条件,提高旗叶光合作用,提高光能利用率和作物产量。0.01%苦豆子处理效果最优,0.01%孜然甲醇提取物次之。  相似文献