甲醇作为船舶燃料研究展望

减少船舶温室气体排放和满足越来越严格的NOx排放控制法规,甲醇作为一种可再生低碳燃料已经在船舶领域开展了大量研究。对甲醇的生产及燃料特点和甲醇在发动机上应用的研究现状进行综述。通过分析得出,虽然甲醇在船舶运输和储存上技术已经成熟,但由于甲醇单位体积热值相对较低,需要更大的船舶燃料储存空间。发动机使用甲醇燃料可以有效降低NOx和碳烟颗粒的排放,同时会产生甲醇和甲醛等污染物。相较于燃料掺混和直接压燃,柴油引燃甲醇发动机更适用于船用动力。

生物柴油在船用低速机上的燃烧分析研究

To study the applicability of biodiesel in marine engines,this research investigated the performance,combustion characteristics,and emission characteristics of biodiesel(B100),diesel,and a 50%volume blend of the two fuels(B50)in a marine engine.This study was conducted on a 4-cylinder,520 mm-bore,two-stroke,low-speed marine engine with a common rail fuel and exhaust gas charge system.The three fuels were tested at different loads from 25%–100%with a step size of 25%.Results showed that the fuel consumption of pure biodiesel increased by about 13.5%and 3.8%relative to that of diesel at 25%and 100%loads,respectively,and by about 6%at 50%and 75%loads.In-cylinder combustion pressure was slightly reduced when the engine ran on biofuel,and black carbon emissions from biodiesel were reduced by an average of 54.7%.Compared with those from diesel,the carbon CO and total hydrocarbon emissions from B100 were reduced by 11.3%and 39%,respectively.Nitroxide emissions were elevated for B100 and B50 under all loading conditions.The properties of B50 blended diesel lie between those of B100 and diesel.In terms of combustion characteristics and emissions,biodiesel can be used without changing the engine parameters and can effectively reduce pollution,such as black carbon and carbon monoxide.

船舶柴油机黑炭排放因子测量

为计算船舶柴油机黑炭排放的具体数量,评估船舶柴油机黑炭排放的现状,必须准确地测量出各种船舶发动机在不同燃油条件下的黑炭排放因子。利用船用二冲程柴油机台架,对柴油机尾气排放物进行监测,研究黑炭排放因子的测量与计算方法。对硫的质量分数分别为1.0%、0.5%、0.1%的3种燃油条件下的发动机黑炭及其他污染物排放进行实验研究,分析不同燃油对各污染物排放的影响。计算得出3种燃油条件下船舶黑炭基于做功的排放因子分别为9.12、7.51、1.34 mg/(kW·h),基于燃油消耗的排放因子分别为47.56、38.34、7.53 g/t,为船舶柴油机黑炭排放的相关研究提供依据。

汽车发动机常见设计与制造缺陷研究

这几年我国社会经济发展速度越来越快,汽车人均占有量数值也在逐步攀升。为了让汽车产业能够蓬勃发展,为其提供更加广阔的空间,汽车发动机作为汽车产品提供动力的最重要内容,性能比和使用的年限占据了非常关键的作用。在设计和制造上存在的普遍问题时,需要我国汽车产业的生产企业了解到现在生产过程中之所以会出现缺陷的原因。