Producer gas through gasification of biomass can be used as an alternate fuel in rural areas due to high potential of biomass resources in India.Experiments were conducted to study the performance of a diesel engine(f...Producer gas through gasification of biomass can be used as an alternate fuel in rural areas due to high potential of biomass resources in India.Experiments were conducted to study the performance of a diesel engine(four stroke,single cylinder,5.25 kW) with respect to its thermal efficiency,specific fuel consumption and diesel substitution by use of diesel alone and producer gas-cum-diesel(dual fuel mode).Three types of biomass,i.e.wood chips,pigeon pea stalks and corn cobs were used for generation of producer gas.A producer gas system consisting of a downdraft gasifier,a cooling cum cleaning unit,a filtering unit and a gas air mixing device was designed,fabricated and used to power a 5.25 kW diesel engine on dual fuel mode.Performance of the engine was reported by keeping biomass moisture contents as 8%,12%,16%,and 21%,engine speed as 1 600 r/min and with variable engine loads.The average value of thermal efficiency on dual fuel mode was found slightly lower than that of diesel mode.The specific diesel consumption was found to be 60%-64% less in dual fuel mode than that in diesel mode for the same amount of energy output.The average diesel substitution of 74% was observed with wood chips followed by corn cobs(78%) and pigeon pea stalks(82%).Based on the performance studied,the producer gas may be used as a substitute or as supplementary fuel for diesel conservation,particularly for stationary engines in agricultural operations in the farm.展开更多
The effect of temperature and metal ion components on the viscosity of HPAM solution was studied by means of orthogonal method.Five factors and 4 levels were considered for the orthogonal design.The five factors inclu...The effect of temperature and metal ion components on the viscosity of HPAM solution was studied by means of orthogonal method.Five factors and 4 levels were considered for the orthogonal design.The five factors included temperature,contents of Na+,Mg2+,Ca2+ and S2-,and the four levels mainly considered the level of produced water components in main oilfields in China.The experiment results show that temperature is the most important factor to control HPAM solution viscosity prepared by produced water.The effect of ions was in order of Na+>S2->Mg2+>Ca2+.The mechanism of each factor influencing viscosity was also discussed.Based on the actual condition of Nanyang oilfield,the desulfurization was used to improve the solution viscosity,and satisfactory result was obtained.展开更多
A laser-produced plasma(LPP) source was built using liquid as target and a Nd:YAG laser as the irradiation laser, and the LPP source's radiation with ethanol and acetone target respectively was measured by an AXUV...A laser-produced plasma(LPP) source was built using liquid as target and a Nd:YAG laser as the irradiation laser, and the LPP source's radiation with ethanol and acetone target respectively was measured by an AXUV100 silicon photodiode combined with a McPHERSON model 247 grazing incidence monochromator of the resolution Δλ≤0.075 nm and the wavelength scanning interval 0.5 nm. Both ethanol and acetone target LPP source had EUV emission at 11～20 nm wavelength. The comparison between the spectra of the two kinds of target materials shows that all the two kinds of target source's spectra are the result of oxygen ions' transitions under current source's parameters, but the spectrum intensity from different target sources is different. The spectra intensity from the ethanol target is higher than that from the acetone target. In addition, the target liquid is forced into the vacuum chamber by the background pressure supported by the connected external high pressure gas, and the influence of the background pressure on the source's intensity is investigated.展开更多
Pulsed laser produced plasmas(LPP)are important for industrial applications and fundamental researches,and their complex,multi-physical and cross-chemical processes need to be investigated more comprehensively.In this...Pulsed laser produced plasmas(LPP)are important for industrial applications and fundamental researches,and their complex,multi-physical and cross-chemical processes need to be investigated more comprehensively.In this work,images of the luminous plasma,the spatial density distribution,and the plasma parameters are experimentally investigated by using fast ICCD photography,schlieren photography,and optical emission spectroscopy.Plasmas are produced by a 1 064 nm,15 ns Nd:YAG laser.Free expanding and splitting phenomena are observed in vacuum(at the pressure of about 1×10 3Pa)and air(at the pressure of 20 Pa)using fast photography,respectively.Meanwhile,shock waves formed in the atmospheric laser produced plasma are visualized by schlieren photography.The formation of shock waves is interpreted with the Sedov-Taylor theory,and an averaged expansion velocity about 375 m/s of the shock waves is estimated during 200～1 000 ns.Atmospheric air is found to have significant confinement effects on the plasma expansions compared to that in vacuum or low pressure ambient.Based on the optical emission spectroscopy,after 1 000 ns,at 0.6 mm above the target,the plasma temperature is about 7 800 K and the electron number density is approximately 0.64×1016cm-3.展开更多
文摘Producer gas through gasification of biomass can be used as an alternate fuel in rural areas due to high potential of biomass resources in India.Experiments were conducted to study the performance of a diesel engine(four stroke,single cylinder,5.25 kW) with respect to its thermal efficiency,specific fuel consumption and diesel substitution by use of diesel alone and producer gas-cum-diesel(dual fuel mode).Three types of biomass,i.e.wood chips,pigeon pea stalks and corn cobs were used for generation of producer gas.A producer gas system consisting of a downdraft gasifier,a cooling cum cleaning unit,a filtering unit and a gas air mixing device was designed,fabricated and used to power a 5.25 kW diesel engine on dual fuel mode.Performance of the engine was reported by keeping biomass moisture contents as 8%,12%,16%,and 21%,engine speed as 1 600 r/min and with variable engine loads.The average value of thermal efficiency on dual fuel mode was found slightly lower than that of diesel mode.The specific diesel consumption was found to be 60%-64% less in dual fuel mode than that in diesel mode for the same amount of energy output.The average diesel substitution of 74% was observed with wood chips followed by corn cobs(78%) and pigeon pea stalks(82%).Based on the performance studied,the producer gas may be used as a substitute or as supplementary fuel for diesel conservation,particularly for stationary engines in agricultural operations in the farm.
基金Project(2007AA06Z214) supported by the National High-Tech Research and Development Program of ChinaProject(ts20070704) supported by Taishan Scholars Construction EngineeringProject(200873181) supported by National Natural Science Foundation of China
文摘The effect of temperature and metal ion components on the viscosity of HPAM solution was studied by means of orthogonal method.Five factors and 4 levels were considered for the orthogonal design.The five factors included temperature,contents of Na+,Mg2+,Ca2+ and S2-,and the four levels mainly considered the level of produced water components in main oilfields in China.The experiment results show that temperature is the most important factor to control HPAM solution viscosity prepared by produced water.The effect of ions was in order of Na+>S2->Mg2+>Ca2+.The mechanism of each factor influencing viscosity was also discussed.Based on the actual condition of Nanyang oilfield,the desulfurization was used to improve the solution viscosity,and satisfactory result was obtained.
文摘A laser-produced plasma(LPP) source was built using liquid as target and a Nd:YAG laser as the irradiation laser, and the LPP source's radiation with ethanol and acetone target respectively was measured by an AXUV100 silicon photodiode combined with a McPHERSON model 247 grazing incidence monochromator of the resolution Δλ≤0.075 nm and the wavelength scanning interval 0.5 nm. Both ethanol and acetone target LPP source had EUV emission at 11～20 nm wavelength. The comparison between the spectra of the two kinds of target materials shows that all the two kinds of target source's spectra are the result of oxygen ions' transitions under current source's parameters, but the spectrum intensity from different target sources is different. The spectra intensity from the ethanol target is higher than that from the acetone target. In addition, the target liquid is forced into the vacuum chamber by the background pressure supported by the connected external high pressure gas, and the influence of the background pressure on the source's intensity is investigated.
基金Project supported by National Natural Science Foundation of China（51237006）.
文摘Pulsed laser produced plasmas(LPP)are important for industrial applications and fundamental researches,and their complex,multi-physical and cross-chemical processes need to be investigated more comprehensively.In this work,images of the luminous plasma,the spatial density distribution,and the plasma parameters are experimentally investigated by using fast ICCD photography,schlieren photography,and optical emission spectroscopy.Plasmas are produced by a 1 064 nm,15 ns Nd:YAG laser.Free expanding and splitting phenomena are observed in vacuum(at the pressure of about 1×10 3Pa)and air(at the pressure of 20 Pa)using fast photography,respectively.Meanwhile,shock waves formed in the atmospheric laser produced plasma are visualized by schlieren photography.The formation of shock waves is interpreted with the Sedov-Taylor theory,and an averaged expansion velocity about 375 m/s of the shock waves is estimated during 200～1 000 ns.Atmospheric air is found to have significant confinement effects on the plasma expansions compared to that in vacuum or low pressure ambient.Based on the optical emission spectroscopy,after 1 000 ns,at 0.6 mm above the target,the plasma temperature is about 7 800 K and the electron number density is approximately 0.64×1016cm-3.
