点火和喷氢正时对增压直喷氢内燃机性能、燃烧和排放特性影响
Effects ofignition and injection timing on performance, combustion and emissions characteristics of a turbo-charged direct injection hydrogen engine
氢气具备可再生、零碳排放和良好的经济效益,其作为内燃机的替代燃料在“双碳”背景下具有重要战略意义。在利用氢能的利用中,直喷氢内燃机(DI-HICE)具有高动力性、高经济性和零碳排放等优势。本文主要研究了点火正时和喷射正时对涡轮增压直喷氢内燃机的性能、燃烧和排放特性的影响。结果表明,通过调整点火正时,推迟燃烧重心,降低气缸温度,最多可以减少92%的氮氧化物排放,而涡轮增压器可以弥补延迟点火造成的部分能量损失;同时,推迟喷射正时可以使氢内燃机的有效热效率 (BTE) 提高1.47%,但同时也会使混合气不均匀,导致缸内最大爆发压力升高0.27 MPa, 压力升高率从0.47 MPa/°CA提高到1.06 MPa/°CA。此外,点火正时和喷油正时的优化需要考虑氮氧化物(NOx)排放特性(接近零排放:NOx < 20ppm)。
Hydrogen shows promise as an alternative fuel for combustion engines due to its renewability, zero carbon emissions, and favorable economic efficiency. In the process of utilizing hydrogen, the direct-injection (DI) hydrogen internal combustion engine (HICE) has been proven to generate significant power with high thermal efficiency and a low risk of abnormal combustion. This study investigates the effects of the ignition timing and injection timing influence the turbocharged DI-HICE performance, combustion and emissions characteristics. The results show that by adjusting the ignition timing, delaying the combustion center of gravity and lowering the cylinder temperature, the nitrogen oxide emission can be reduced by up to 92%, and the turbocharger can make up for part of the energy loss caused by delayed ignition. At the same time, delaying injection timing can increase the BTE of hydrogen engines by 1.47%, but at the same time, it will also make the mixture uneven, resulting in a maximum cylinder pressure increase of 0.27 MPa, and the pressure increase rate from 0.47 MPa/°CA to 1.06 MPa/°CA.. The optimization of ignition timing and injection timing needs to consider the nitrogen oxides (NOx) emissions characteristics (Near zero emissions: NOx < 20ppm). Moreover, higher coolant temperatures can reduce 3.33% of the heat transfer losses proportion and 2.22kW of the other energy losses in the load of 0.4 MPa.
张诗蔚;孙柏刚;罗庆贺;赖丰羽;王康达;
北京理工大学大学 机械与车辆学院,北京100081;北京理工大学大学 机械与车辆学院,北京100081;北京理工大学大学 机械与车辆学院,北京100081;北京理工大学大学 机械与车辆学院,北京100081;北京理工大学大学 机械与车辆学院,北京100081;
TK4
Direct-injection hydrogen engine Ignition timing Injection timing Energydistribution characteristics
1-9 / 9
评论