Purpose

The purpose of this paper is to investigate power performance, economy and hydrocarbons (HC)/carbon monoxide (CO) emissions of diesel fuel on a two-stoke direct injection (DI) spark ignition (SI) engine.

Design/methodology/approach

Experimental study was carried out on a two-stroke SI diesel-fuelled engine with air-assisted direct injection, whose power performance and HC/CO emissions characteristics under low-load conditions were analysed according to the effects of ignition energy, ignition advance angle (IAA), injection timing angle and excess-air-ratio.

Findings

The results indicate that, for the throttle position of 10%, a large IAA with adequate ignition energy effectively increases the power and decrease the HC emission. The optimal injection timing angle for power and fuel consumption is 60° crank angle (CA) before top dead centre (BTDC). Lean mixture improves the power performance with the HC/CO emissions greatly reduced. At the throttle position of 20%, the optimal IAA is 30°CA BTDC. The adequate ignition energy slightly improves the power output and greatly decreases HC/CO emissions. Advancing the injection timing improves the power and fuel consumption but should not exceed the exhaust port closing timing in case of scavenging losses. Burning stoichiometric mixture achieves maximum power, whereas burning lean mixture obviously reduces the fuel consumption and the HC/CO emissions.

Practical implications

Gasoline has a low flash point, a high-saturated vapour pressure and relatively high volatility, and it is a potential hazard near a naked flame at room temperature, which can create significant security risks for its storage, transport and use. The authors adopt a low volatility diesel fuel for all vehicles and equipment to minimise the number of different devices using various fuels and improve the potential military application safety.

Originality/value

Under low-load conditions, the two stroke port-injected SI engine performance of burning heavy fuels including diesel or kerosene was shown to be worse than those of gasoline. The authors have tried to use the DI method to improve the performance of the diesel-fuelled engine in starting and low-load conditions.

中文翻译：

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柴油二冲程直喷火花点火气动活塞发动机低负荷性能研究

目的

本文的目的是研究两冲程直喷 (DI) 火花点火 (SI) 发动机上柴油燃料的动力性能、经济性和碳氢化合物 (HC)/一氧化碳 (CO) 排放。

设计/方法/方法

对空气辅助直喷二冲程SI柴油发动机进行了试验研究，根据点火能量、点火提前角（ IAA)、喷射正时角和过量空气比。

发现

结果表明，对于10%的节气门位置，具有足够点火能量的大IAA有效地增加了功率并减少了HC排放。功率和燃料消耗的最佳喷射正时角是上止点 (BTDC) 前 60° 曲柄角 (CA)。稀混合气提高了动力性能，同时大大减少了 HC/CO 排放。在 20% 的节气门位置，最佳 IAA 为 30°CA BTDC。充足的点火能量略微提高了功率输出并大大降低了HC/CO排放。提前喷射正时可提高功率和燃油消耗，但不应超过排气口关闭正时，以防出现扫气损失。燃烧化学计量混合气可实现最大功率，而燃烧稀薄混合气明显降低燃料消耗和 HC/CO 排放。

实际影响

汽油闪点低、饱和蒸气压高、挥发性相对较高，常温下靠近明火具有潜在危害，对其储存、运输和使用产生重大安全隐患。作者为所有车辆和设备采用低挥发性柴油燃料，以尽量减少使用各种燃料的不同设备的数量，并提高潜在的军事应用安全性。

原创性/价值

在低负荷条件下，燃烧包括柴油或煤油在内的重质燃料的二冲程端口喷射 SI 发动机性能比汽油差。作者尝试使用 DI 方法来提高柴油发动机在启动和低负载条件下的性能。