6135 柴油发动机动态性能试验

波动负荷是工程机械、拖拉机等作业机械负荷工况最重要的特征之一．介绍了在Ｆ３５快速响应水力测功机上对６１３５柴油机所进行的某些试验，分析了各种因素对柴油机动态响应特性的影响．     

远洋拖网渔船电力推进系统及其控制

柴油机动力渔船存在工作负荷波动大、低负荷油耗高、污染严重和动力特性差等缺点。为解决柴油机动力远洋渔船长时间低负荷、大功率波动情况下低效率、高排放的问题,文章提出一种远洋渔船电力推进动力系统的优化拓扑结构及其控制方式,其采用双电枢、单螺旋桨的推进系统拓扑,并根据其负荷变化规律采取单、双电枢工作下的优化控制策略,实现渔船综合能效的提升。经实船验证,优化后的渔船控制策略可降低约5%的综合燃油消耗率。     

柴油机过热故障及诊断

工程机械工作在恶劣的环境中，负荷重且变化较大。柴油机是工程机械的主要动力源，柴油机过热故障危害较大，易引起机件的变形、熔化、卡死和拉缸等，会增加燃油消耗、降低输出功率。因此，发现和排除柴油机的过热故障，对于充分发挥工程机械的经济性和动力性，提高使用寿命有着十分重要的意义。１柴油机过热故障产生的原因引起柴油机过热的原因很多，尤其是在坡道进行大负荷工作，或在环境气温较高的炎热夏季和沙漠高原地带工作时，冷却系统受到影响而不能充分起作用很易引起过热故障。长时间的超载和高速运转，柴油机的温度也会急剧升高甚…     

柴油机常见故障应急修理“六法”

柴油机是土方机械中最常用的动力装置，其工况多变、工作地点不固定、载荷波动大、工作条件恶劣、维护保养条件差，在工作中会出现一些常见故障。根据柴油机各部件的作用、结构和工作原理的不同，结合工作实践，归纳总结出了以下快速应急排除柴油机常见故障的方法，供同仁参考。     

全液压铣刨机转速波动问题探讨

通过对铣刨过程力学模型的理论分析,对影响铣刨鼓转速波动的因素及提高铣刨鼓转速稳定性的方法进行了探讨,指出影响铣刨鼓转速波动的主要因素是铣刨负荷、铣刨机行走速度、铣刨厚度。提高液压系统的刚度,减小负荷增加时液压系统泄漏量,能够有效提高铣刨机作业质量、作业效率和铣刨鼓转速稳定性,对铣刨机整机性能和节能减排也有贡献。     

柴油机着火异常敲击声的故障判断与排除

柴油机着火敲击声发生在滞燃期终了时，由于燃烧室内积聚燃料过多，点火时燃气压力上升过于剧烈，造成活塞与气缸壁以及曲柄连杆机构和相对运动零部件之间产生冲击，而发出的一种异常的金属敲击声。高速运转时的着火敲击声比较尖锐、清脆；在怠速与中速之间无负荷运转时，是连贯的“嘎啦嘎啦”的响声。这些响声是随负荷的增大而增大的，并严重影响柴油机的正常工作，加剧柴油机的损坏，缩短使用寿命，因此必须认真进行判断排除。 当柴油机产生的异响是有规律的，每喷油一次发出一次敲击声，并伴有机身抖动，则可由怠速或中低速向高速加大油…     

柴油机常见故障应急修理“六法”

柴油机是土方机械中最常用的动力装置,其工况多变、工作地点不固定、载荷波动大、工作条件恶劣、维护保养条件差,在工作中会出现一些常见故障。根据柴油机各部件的作用、结构和工作原理的不同,结合工作实践,归纳总结出了以下快速应急排除柴油机常见故障的方法,供同仁参考。     

论农村柴油机喷油泵使用寿命的原因

<正>在拖拉机、农用车的使用中,如何延长柴油机喷油泵系统的使用寿命,是每一位驾驶员都非常关心的。除日常生活工作中需要正确、合理的使用外,还需要加强保养和维修,在此,仅对保养和维修不当造成喷油泵工作失常的原因进行分析,提出几点改进措施。柴油机喷油泵系统的作用是把适量、干净的柴油以足够的压力按照柴油机的发火次序和负荷大小,在规定的时刻和延续时间内,喷入燃烧室。多缸柴油机喷油泵保证各缸供油大小相     

山东禹城污水处理厂主体工艺调试经验与分析

介绍了禹城污水处理厂的调试运行状况，并从培菌启动条件、设备配置、水力流态等方面对调试过程中出现的问题进行了分析与探讨，在此基础上提出了适合中小城镇污水处理厂面对进水水量波动较大，冲击负荷高的情况下的调试经验。     

压路机用发动机的常见故障及排除（一）

柴油机发生故障时，会出现一些异常迹象，例如：①异常声响，如不正常的敲击声、爆炸声、吹嘘声等；②异常动作，如柴油机不宜启动，不能带负荷运转，工作中伴有剧烈振动，运转不稳定甚至突然停车；③异常排放，如排气管冒黑烟、白烟、蓝烟；④异常温度，如润滑油和冷却水温度过高，     

Parametric optimisation of exergy destruction in small DI diesel engine fuelled with neem biodiesel using the Taguchi method

ABSTRACT

Large amount of emissions from vehicles have led to the degradation of urban air quality and have resulted in serious health issues. Biodiesel, a substitute fuel for diesel engine, is receiving great attention worldwide. This work investigates the merits of using neem-biodiesel and diesel blends for single cylinder small direct injection diesel engine. The energy (the first law) and exergy (the second law) analyses of direct injection diesel engine using neem-biodiesel blends have been presented. Taguchi’s ‘L’ 16’ orthogonal array has been used for the design of experiments. The engine was tested at different engine speeds, load percentages and blend ratios, using neem biodiesel. The results show that the optimum operating conditions for minimum brake specific fuel consumption are achieved when the engine speed is 1900?rev/min, load percentage is 75 and the engine is fuelled with B40.     

Particle size distribution from a GTL engine

Measurements of exhaust particle number concentration and size distribution from an engine fueled with GTL at different engine loads and speeds were carried out by using a two-stage dilution system. The results for GTL were compared with those from the original engine fueled with diesel. The fuel composition and engine operation condition had significant effects on the exhaust particle size distribution, the total exhaust particle number and volume concentrations. For both fuels, the load had no significant influence on the total exhaust particle number concentration at middle speed, while the total exhaust particle number concentration increased with the increase of the load at high speed. At 1400 rpm and 2200 rpm, the total exhaust particle volume concentration increased as the load increased for both fuels. GTL was found to be a "cleaner" fuel. Compared with diesel, under the same operation conditions, the total exhaust particle number concentrations decreased 18-92%, and the total exhaust particle volume concentrations for GTL decreased 21-59%.     

Performance of a twin cylinder dual-fuel diesel engine using blends of neat Karanja oil and producer gas

In the present study, performance and emission analysis are done in a twin cylinder four-stroke dual-fuel diesel engine in two cases of operation. In the first case, the engine is tested using diesel, K10 (10% neat oil+90% diesel) and K20 (20% neat oil+80% diesel) in single mode and in the dual-fuel mode with an optimum producer gas flow rate of 21.49 kg/h under different load conditions. In the second case, the engine is tested using the same test fuels in the dual-fuel mode at different gas flow rates under a constant load of 10 kW. The study reveals that the dual-fuel operation of all test fuels shows a lower engine performance and better control of smoke and oxide of nitrogen emission compared with their single-mode operation under all load conditions. Whereas other emission parameters such as carbon monoxide, carbon dioxide and hydrocarbon are at a higher level.     

Effects of hydrocarbon fuel extracted from waste transformer oil on a DI diesel engine

In this study, hydrocarbon fuel (HCF) was derived from waste transformer oil through a traditional base-catalysed trans-esterification process. The experimental investigations using its blends of 25%, 50%, 75%, 100% and diesel fuel were carried out separately. The HCF obtained from waste transformer oil is used in a direct injection (DI) diesel engine without any engine modification to evaluate its performance, emission and combustion characteristics. The results indicate that the engine operating on test fuel blends shows a marginal increase in brake thermal efficiency (BTE) with a significant reduction in smoke. Nitrous oxides (NO_x) emission was slightly higher for test fuel blends than for diesel. The results show that at maximum load conditions, 25% HCF reduces carbon monoxide, smoke and hydrocarbon emission by 50%, 31% and 10%, respectively, whereas 50% HCF shows a greater BTE than other blends and is 12% higher than that of the diesel fuel. The combustion characteristics of fuel blends closely followed those of standard diesel.     

Performance characteristics of palm kernel biodiesel and its blend in a CI engine

The full load performance characteristics of a diesel engine fuelled with palm kernel biodiesel and its blend with diesel fuel are presented in this paper. The biodiesel was synthesised from Nigerian palm kernel oil through a direct base catalysed transesterification process using sodium hydroxide and methanol as the catalyst and alcohol, respectively. The produced biodiesel was blended with neat diesel fuel at a ratio of 20% biodiesel to 80% diesel by volume. The engine torque, brake power, brake specific fuel consumption and brake mean effective pressure were determined for each of the fuels at 400 rpm intervals between 1200 and 3600 rpm. In other to establish a baseline for comparison, the engine was first run on neat diesel. The test results interestingly revealed that the fuel blend (B20) produced higher torque at low and medium engine speeds than neat diesel fuel and unblended biodiesel (B100). This suggests that it can be a suitable fuel for heavy duty engines that are required to develop high torque at low engine speeds. It was also observed that diesel fuel developed higher torque and brake power than the unblended biodiesel (B100) at all tested speeds and showed the least brake specific fuel consumption possibly because of its higher heating value. In all, the palm kernel biodiesel and its blend (B20) exhibited performance characteristic trends very similar to that of diesel fuel thus confirming them as suitable alternative fuels for compression ignition engines.     

工程机械中电源处理电路的优化设计

市政工程中所用到的工程机械,如挖掘机、吊车、叉车、铺路机等,因输出功率大,需采用柴油机作为动力源;然而,柴油机所提供的电源非常不稳定,影响了监控其运行状态的电子设备。介绍了一般的电源处理电路中采取的三端稳压芯片降压、稳压芯片和滤波电容组合以及前置熔丝等3种方法。着重就电源处理电路的优化设计、电路构成及功能分析进行了论述。该项技术运用于叉车的监控系统,能保证其正常运行。该叉车组合仪表用电源电路已申请专利并获批准。     

Effect of the addition of 1-pentanol on engine performance and emission characteristics of diesel and biodiesel fuelled single cylinder diesel engine

ABSTRACT

Bioalcohols have recently become one of the promising alternate fuels. Lower alcohols exhibit some problems like phase separation, stability issues, storage problems, corrosion etc. Hence, the addition of higher alcohols is regarded least-problematic and the concept of using higher alcohols as fuel blends is relatively new. In this article, the effects of the addition of higher alcohol (1-pentanol) on engine performance and emission characteristics are discussed. Two reference fuels (diesel and biodiesel derived from waste cooking oil) and two test fuels (blends of 20% of 1-pentanol and 80% of either diesel or biodiesel) are tested in a single cylinder compression ignition diesel engine for six load conditions (0, 4, 8, 12, 16, and 20?kg) at a constant speed of 1200?rpm. The engine performance and emission characteristics are determined and discussed.     

Experimental analysis of diesel engine exhaust gas coupled with water desalination for improved potable water production

Exhaust gas temperature of diesel engine is higher compared with a petrol engine and also creates higher pollution in the environment. Exhaust gas recirculation system and many other systems have used for reuse of exhaust gas to improve the performance of diesel engine, but the use of diesel engine for production of potable water production is still unattended by the researchers. The main aim of this research work is to use the waste heat of exhaust gas for potable water production from the low-capacity desalination system integrated with a evaporator and condenser unit. In this work, single pass evaporator and water-cooled condenser used for evaporation and condensation of saline water were designed and fabricated by locally available materials. The experiments were performed on a 10?HP diesel engine with varying the load to get potable water. It has found that 4.2?L/hr of potable water is obtained from the exhaust gas without varying the performance of the engine. Also, it has found that, temperature of saline water is heated more than 70°C in the condenser unit.     

柴油机缸内燃烧过程对羰基物排放的影响

采用生物柴油、柴油及其调合油进行柴油机台架试验,测量了缸内瞬变压力随曲轴转角的变化情况,通过放热规律计算,结合柴油机羰基物排放的测量结果,分析了缸内燃烧过程与羰基类污染物生成之间的内在关系。研究结果表明,预混燃烧阶段发生燃料氧化反应,形成甲醛、C7、C5、CO、C2H2等燃烧中间产物;随着负荷的增加,扩散燃烧期延长,成为羰基类燃烧中间产物再次氧化分解的主要阶段;随着负荷的增大,缸内温度、压力提高,滞燃期缩短,在高温、高压区域的滞留时间延长,羰基类污染物被再次氧化、转化几率增加;高负荷时,排气温度较高,有利于羰基类物质发生再次氧化。