应用自行开发的柴油机瞬态工况测控系统,研究了GTL(Gas to liquid)添加比例对小型直喷式柴油机稳态及恒转速增转矩瞬态工况下燃烧特性的影响规律。结果表明:在稳态和恒转速增转矩瞬态工况下,GTL添加比例对燃烧参数的影响具有基本相同的...应用自行开发的柴油机瞬态工况测控系统,研究了GTL(Gas to liquid)添加比例对小型直喷式柴油机稳态及恒转速增转矩瞬态工况下燃烧特性的影响规律。结果表明:在稳态和恒转速增转矩瞬态工况下,GTL添加比例对燃烧参数的影响具有基本相同的规律,随着GTL燃料添加比例的增加,着火始点提前,滞燃期缩短,预混合燃烧期和预混合燃烧量减小,缸内压力峰值、放热率峰值、燃烧温度有所降低,有利于降低NOx的排放量和燃烧噪声。当添加少量GTL燃料时,燃烧持续期延长,随着GTL添加比例的增加,燃烧持续期有所缩短。100%GTL燃料的燃烧持续期与柴油相当。展开更多
In this paper the premixed catalytic combustion emissions such as CO, unburned hydrocarbon (UHC), NOx and the temperature distribution in the catalytic monolith with ultra low concentration of Pd were studied. Three t...In this paper the premixed catalytic combustion emissions such as CO, unburned hydrocarbon (UHC), NOx and the temperature distribution in the catalytic monolith with ultra low concentration of Pd were studied. Three types of monoliths were used for experiments and the temperature of preheated air was respectively 50℃ , 100℃ and 200℃ . The results showed that preheated air made radial temperature in the catalytic monolith uniform which helped to avoid local hot spots so as to decrease NOx emission. The experiment also proved that the shorter monolith showed much better catalytic combustion performance than longer one and the temperature at the exit of the shorter monolith was relatively lower. On the contrary, the temperature was higher in the longer monolith and the lethal NOx emission was slightly increased.展开更多
A statistical-mechanical-based equation of state(EOS)for pure substances,the Tao-Mason equation of state,is successfully extended to prediction of the(p-v-T)properties of fourteen natural gas mixtures at temperatures ...A statistical-mechanical-based equation of state(EOS)for pure substances,the Tao-Mason equation of state,is successfully extended to prediction of the(p-v-T)properties of fourteen natural gas mixtures at temperatures from 225 K to 483 K and pressures up to 60.5 MPa.This work shows that the Tao-Mason equation of state for multicomponent natural gas is predictable with minimal input information,namely critical temperature,critical pressure,and the Pitzer acentric factor.The calculated results agree well with the experimental data.From a total of 963 data of density and 330 data of compressibility factor for natural gases examined in this work,the average absolute deviations(AAD)are 1.704%and 1.344%,respectively.The present EOS is further assessed through the comparisons with Peng-Robinson(PR)equation of state.For the all of mixtures Tao-Mason(TM)EOS outperforms the PR EOS.展开更多
文摘应用自行开发的柴油机瞬态工况测控系统,研究了GTL(Gas to liquid)添加比例对小型直喷式柴油机稳态及恒转速增转矩瞬态工况下燃烧特性的影响规律。结果表明:在稳态和恒转速增转矩瞬态工况下,GTL添加比例对燃烧参数的影响具有基本相同的规律,随着GTL燃料添加比例的增加,着火始点提前,滞燃期缩短,预混合燃烧期和预混合燃烧量减小,缸内压力峰值、放热率峰值、燃烧温度有所降低,有利于降低NOx的排放量和燃烧噪声。当添加少量GTL燃料时,燃烧持续期延长,随着GTL添加比例的增加,燃烧持续期有所缩短。100%GTL燃料的燃烧持续期与柴油相当。
基金Supported by the Key Project of the National 973 Program of China (No.2005CB724201)the Natural Science Foundation ofBeijing (No.06C0002)the Beijing Education Commission Key Laboratory of Heat Transfer and Energy Conversion Fund(No.05005790200406).
文摘In this paper the premixed catalytic combustion emissions such as CO, unburned hydrocarbon (UHC), NOx and the temperature distribution in the catalytic monolith with ultra low concentration of Pd were studied. Three types of monoliths were used for experiments and the temperature of preheated air was respectively 50℃ , 100℃ and 200℃ . The results showed that preheated air made radial temperature in the catalytic monolith uniform which helped to avoid local hot spots so as to decrease NOx emission. The experiment also proved that the shorter monolith showed much better catalytic combustion performance than longer one and the temperature at the exit of the shorter monolith was relatively lower. On the contrary, the temperature was higher in the longer monolith and the lethal NOx emission was slightly increased.
文摘A statistical-mechanical-based equation of state(EOS)for pure substances,the Tao-Mason equation of state,is successfully extended to prediction of the(p-v-T)properties of fourteen natural gas mixtures at temperatures from 225 K to 483 K and pressures up to 60.5 MPa.This work shows that the Tao-Mason equation of state for multicomponent natural gas is predictable with minimal input information,namely critical temperature,critical pressure,and the Pitzer acentric factor.The calculated results agree well with the experimental data.From a total of 963 data of density and 330 data of compressibility factor for natural gases examined in this work,the average absolute deviations(AAD)are 1.704%and 1.344%,respectively.The present EOS is further assessed through the comparisons with Peng-Robinson(PR)equation of state.For the all of mixtures Tao-Mason(TM)EOS outperforms the PR EOS.
