China 
Africa 
Explore chapters and articles related to this topic
Environmental Impacts of Biofuel-Fired Small Boilers and Gasifiers
Published in Mateusz Szubel, Mariusz Filipowicz, Biomass in Small-Scale Energy Applications: Theory and Practice, 2019
Jozef Viglasky, Juraj Klukan, Nadezda Langova
Carbon monoxide poisoning: Carbon monoxide is a major constituent of producer gas and is by far the most common cause of gas poisoning. It is particularly insidious owing to its lack of color or smell. The accepted threshold limit value (TLV) is 50 ppm CO (0.005 vol.%), although concentration and exposure are closely linked. There is extensive documentation available on the effects, treatment, and controls laid down by the relevant statutory authorities. Since carbon monoxide is an odorless, colorless gas, it may be detected only through instrumentation, and personal detectors are necessary when working in confined spaces. All operating personnel should be aware of the hazards presented by the gas. The best way of avoiding the risk of CO poisoning is to build the gas generator in the open with the minimum of containment and with adequate ventilation, particularly where gases may collect.
Engine performance
Published in Mohammad H. Sadraey, Aircraft Performance, 2017
Turbojet engines, turbofan engines, and turboprop engines all have the same core (i.e., gas generator). A gas generator consists of a compressor, a combustion chamber, and a turbine. The specific fuel consumptions of these three types of turbine engines follow a similar trend. In addition, the piston engine has a completely different configuration. Thus, in terms of specific fuel consumption, turbojet, turbofan, and turboprop engines are grouped together.
Turbojet Engine
Published in Ahmed F. El-Sayed, Aircraft Propulsion and Gas Turbine Engines, 2017
The disadvantage of ramjet engine is that its pressure ratio depends on the flight Mach number. It cannot develop takeoff thrust and does not perform well unless the flight Mach number is much greater than one ([refer to the figure (T/m˙a) vs. M]; Example 3.6, Ramjet). To overcome this disadvantage, a compressor is installed in the inlet duct so that even at zero flight speed, air cannot be drawn into the engine. This compressor is driven by the turbine installed downstream of the combustion chamber and connected to the compressor by a central shaft. Addition of the two rotating parts or modules (compressor and turbine) converts the ramjet into a turbojet. The compressor, combustion chamber, and turbine constitute what is called gas generator. The air is squeezed in the compressor to many times its normal atmospheric pressure and then forced into the combustion chamber. Fuel is sprayed into the compressed air, ignited, and burned continuously in the combustion chamber. This raises the temperature of the fluid mixture to about 1100°F − 1300°F. The resulting burning gases expand rapidly rearward and pass through the turbine, which drives the compressor. The turbine extracts energy from the expanding gases to drive the compressor, which intakes more air. If the turbine and compressor are efficient, the pressure at the turbine discharge will be nearly twice the atmospheric pressure, and this excess pressure is sent to the nozzle to produce a high-velocity stream of gases. These gases bounce back and shoot out of the rear of the exhaust, thus produce a thrust pushing the plane forward. Substantial increases in thrust can be obtained by employing an afterburner or augmenter. It is a second combustion chamber positioned after the turbine and before the nozzle. The afterburner increases the temperature of the gas ahead of the nozzle. The result of this increase in temperature is higher jet velocity and more push. Thus, an increase of about 40% in thrust at takeoff and a much larger percentage at high speeds once the plane is in the air.
Influence of Doped H2O or H2 on Soot Production and Power Capability in the Fuel-rich Gas Generator
Published in Combustion Science and Technology, 2022
Yujun Li, Taichang Zhang, Tao Yuan, Xuejun Fan
In recent years, reusable rocket is a hot spot and a trend of space development at home and abroad, which can greatly reduce the cost of space launch (Donahue et al. 2008). The rocket engine system is the core of the rocket, and the gas generator cycle is one of the main cycle modes of the rocket engine. At present, the most popular reusable Falcon 9 rocket uses the Merlin series engine which employs the rich-fuel gas generator (Vozoff and Couluris 2008). For the LOX/kerosene rocket engine with gas generator cycle, the high concentration of soot and the large area of coke deposition in the pipeline (Edwards 2006) have adverse effects on the rocket engine system and structure, thus reducing the performance and operation life of the rocket engine. It is not conducive to the reuse of the rocket. Therefore, it is necessary to study influential factors on the formation mechanism as well as the amount of soot and coke deposition during the combustion of aviation kerosene. The relevant studies have been performed. In soot formation mechanism, Hai Wang (Wang 2011) reviewed the research status of sooting processes in the past 20 years, including soot precursor formation, particle nucleation, and mass/size growth. Formation mechanism of coke deposition, including the chemical processes of coke deposition formation and the factors affecting deposition content has been extensively studied (Beaver et al. 2005; Heneghan and Zabarnick 1994; Spadaccini, Sobel, Huang 2001). In the gas generator carbon deposition, the effects of mixture ratios and combustion pressure on soot formation and deposition characteristics were studied in a fuel-rich LOX/kerosene gas generator and a GOX/kerosene gas generator (Feng et al. 2017; Lausten, Rousar, Buccella 1985; Lawver 1983). The carbon deposition and soot formation characteristics of RP-3 kerosene under certain conditions were studied (Abdalla et al. 2020; Pei and Hou 2016), which indicates different types of kerosene also affect carbon deposition and the formation of soot. In addition, the development of numerical calculation also enables researchers to further study the characteristics of coke and soot (Foelsche et al. 1994; Yu and Lee 2007). For some hydrocarbon fuels, such as gasoline, the effects of the addition of alcohol and ether on the soot formation and combustion properties of the fuel were studied (Liu et al. 2018; Zhu et al. 2020), but as far as we know the additional components were rarely involved to suppress sooting in aviation kerosene and oxygen combustion. Moreover, influence of the additive on the power capability of combustion products of the gas generator were rarely studied.