二元活性剂对氨高温自着火特性影响分析

In the context of global carbon neutrality, ammonia has received widespread attention as a renewable and carbon-free fuel. The study utilized a shock tube experimental platform to measure the high-temperature ignition delay time of ammonia, ammonia/hydrogen, and ammonia/hydrogen/dimethyl ether (DME) fuels at an equivalence ratio of 1.0 and pressures of 0.14 MPa and 1.0 MPa. Additionally, a kinetic model suitable for high-temperature ignition of ammonia/hydrogen/DME was constructed. Experimental results indicate that the ternary mixture of ammonia/hydrogen/DME exhibits shorter ignition delay periods compared to the binary mixture of ammonia/hydrogen under the same conditions. Specifically, at 1.0 MPa, the ignition delay time (IDT) of the mixed fuel containing 5% H2 and 5% DME is reduced by nearly 45 times compared to pure ammonia at 0.14 MPa. Kinetic analysis reveals that the ternary mixture has a lower spontaneous ignition temperature, making it favorable for application in compression-ignition internal combustion engines. The key factors contributing to its higher reactivity are the significant generation of reactive radicals from DME and H2 during the early oxidation process, which activate the radical pool.