烃类燃料的能量特性

本文对烃类燃料的能量特性进行了分析比较.三种烃(CH_4、C_3H_8、RP-1)分别同液态氧组合,其中含氢较高的CH_4具有最高的比冲和较低的燃烧室温度,其燃烧产物中固炭量低于C_3H_8与RP-1.三种烃分别同液态氧组合的比冲均高于O_2/C_2H_5OH与N_2O_4/(CH_3)_2NNH_2.本文还指出了烃同液氧组合比冲随α与p_c变化的关系.最后,对烃类燃料性能改进问题进行了论述.结果表明,将一定量的液氢加入烃中混合燃烧可提高比冲,减少低α条件下燃烧产物中固态炭量.另一方面,通过加液氢还可使燃气发生器工质的R_cT_c值提高.

THE PERFORMANCES OF HYDROCARBON FUELS

The thermodynamic performance of hydrocarbon fuels are analysed and compared with each other in this paper. In the comparison of hydrocarbons (CH4, C3H8and RP-1),it is shown that higher hydrogen content of O2/CH4 combination leads to the highest specific impules of hydrocarbon propellants based on oxygen. The Tc (combustion chamber temperature) value and solid carbon in the combustion products for O2/CH4combination are lower than those for O2/C3H8 and O2/RP-1. The Is values for hydrocarbon propellants combined with oxygen are also higher than that for O2/C2H5OH as well as N2O4/(CH3)2 NNH2. The variation of Is with oxidizer/fuel ratio and combustion chamber pressure for hydrocarbon fuels combined with oxygen is also presented in- this paper. Finally, further improvement work is presented and studied. It is shown that adding liquid hydrogen is available to increase the specific impulses for hydroca-rbon-O2 systems and to reduce solid carbon in combustion products at lower oxidizer/fuel ratio. On the other hand, the higher Rc Tc value of gaseous working fluid of generator can be obtained by. the. addition of liquid hydrogen.