scholarly journals Analysis of specific heat of compressed gas fuel A and B combustion products in diesels

2021 ◽  
Vol 2021 (2) ◽  
pp. 65-74
Author(s):  
Anatoly Nikolaevich Sobolenko ◽  
Maria Vasilievna Florianskaya
Keyword(s):  
Heat Capacity ◽  
Water Vapor ◽  
Diesel Fuel ◽  
Chemical Elements ◽  
Combustion Products ◽  
Gas Content ◽  
Quantitative Composition ◽  
Fishing Vessels ◽  
Compressed Gas ◽  
Gas Fuel

The article underlines the interest to using gas fuel in diesel engines of the coastal fishing vessels. If the change to liquefied natural gas is limited by the lack of bunkering capabilities in the Russian ports, using compressed gas has become widespread in transport and in the household. A number of gas fueling stations are already available for this purpose. It seems reasonable to start the conversion of the port fleet to compressed gas from using the motor gas bottling equipment for that purpose. It is important to evaluate the change in engine performance parameters when converting to compressed gas. Compressed gas is a mixture of gases such as propane, ethane, butane, methane, etc. There is given the percentage of each gas content, according to GOST. The quantitative composition of the pure compressed gas combustion outcomes, as well as the gas ignited by the ignition diesel fuel was determined by the oxidation reactions of the chemical elements of which they consist, as well as by oxygen from air. As a result of regression analysis applied to define the properties of water vapor and gases, there have been derived linear and quadratic approximating dependences of the heat capacities of gases (CO2, N2) and water vapor (H2O) on temperature. There have been obtained the equations for determining the heat capacity of the combustion products of compressed gas for fuel grade A and B. There have been produced the formulas for determining heat capacity of pure combustion products of compressed gas ignited by the ignition diesel fuel. The obtained expressions are recommended to be used for analysis of the working cycle of a diesel engine running on the compressed gas.

scholarly journals CALCULATING SPECIFIC HEAT OF COMBUSTION PRODUCTS IN GAS MODE DIESEL ENGINES

2019 ◽  
pp. 48-55
Author(s):  
Anatoliy Nickolaevich Sobolenko
Keyword(s):  
Heat Capacity ◽  
Natural Gas ◽  
Specific Heat ◽  
Diesel Engines ◽  
Combustion Products ◽  
Engine Fuel ◽  
Gas Engine ◽  
Fishing Vessels ◽  
Gas Fuel ◽  
Clean Combustion

The task of using natural gas-engine fuel in transport diesel engines (marine and automobile) is very actual. The trends of converting diesel engines to gas mode on ships of the port fleet and fishing vessels are becoming widespread. The importance to clarify the calculation methods of the working process for gas mode diesel engines is growing. Natural gas has been stated to comprise different gases - methane, ethane, propane, butane, carbon monoxide, etc., the percentage correlations of which being presented. There has been studied the method of calculating heat capacity of “pure” combustion products, i.e. under fuel combustion with excessive air coefficient α =1. The chemical reactions of oxidation elements of gas fuel components during its combustion determine the amount of kilomole of combustion products. To determine the heat capacity of the components of the combustion products - CO2, H2O and N2, the known tables of gases and water vapor properties were used. As a result of data processing, approximating linear and quadratic dependences were obtained. Нeat capacities are calculated in the linear formula of the specific heat of “pure” combustion products as the heat capacity of the gas mixture. As a result, a formula for determining the heat capacity of “clean” combustion products of gas fuel has been obtained: CVG = 25.03 + 0.0065· T . For determining the heat capacity of “clean” combustion products of gas fuel with 10% additive of ignition diesel fuel the formula has the following form CVGZH = 24.57 + 0.006· T . The dependences obtained are fairly accurate and recommended for using in the practice of converting diesel engines to gas-engine fuel, as well as when carrying out works and watercraft technology in building the ships and water transport.

Lean Blowout Limit and NOx Production of a Premixed Sub-ppm NOx Burner With Periodic Recirculation of Combustion Products

2004 ◽  
Vol 128 (2) ◽  
pp. 247-254 ◽  
Author(s):  
Jochen R. Kalb ◽  
Thomas Sattelmayer
Keyword(s):  
Natural Gas ◽  
Flue Gas ◽  
Combustion Products ◽  
Gas Content ◽  
Stable Operation ◽  
Reacting Flow ◽  
Nox Emissions ◽  
Current Standard ◽  
Lean Blowout ◽  
Fresh Mixture

The technological objective of this work is the development of a lean-premixed burner for natural gas. Sub-ppm NOx emissions can be accomplished by shifting the lean blowout limit (LBO) to slightly lower adiabatic flame temperatures than the LBO of current standard burners. This can be achieved with a novel burner concept utilizing spatially periodic recirculation of combustion products: Hot combustion products are admixed to the injected premixed fresh mixture with a mass flow rate of comparable magnitude, in order to achieve self-ignition. The subsequent combustion of the diluted mixture again delivers products. A fraction of these combustion products is then admixed to the next stream of fresh mixture. This process pattern is to be continued in a cyclically closed topology, in order to achieve stable combustion of, for example, natural gas in a temperature regime of very low NOx production. The principal ignition behavior and NOx production characteristics of one sequence of the periodic process was modeled by an idealized adiabatic system with instantaneous admixture of partially or completely burnt combustion products to one stream of fresh reactants. With the CHEMKIN-II package, a reactor network consisting of one perfectly stirred reactor (PSR, providing ignition in the first place) and two plug flow reactors (PFR) has been used. The effect of varying burnout and the influence of the fraction of admixed flue gas has been evaluated. The simulations have been conducted with the reaction mechanism of Miller and Bowman and the GRI-Mech 3.0 mechanism. The results show that the high radical content of partially combusted products leads to a massive decrease of the time required for the formation of the radical pool. As a consequence, self-ignition times of 1 ms are achieved even at adiabatic flame temperatures of 1600 K and less, if the flue gas content is about 50–60% of the reacting flow after mixing is complete. Interestingly, the effect of radicals on ignition is strong, outweighs the temperature deficiency and thus allows stable operation at very low NOx emissions.

scholarly journals Temperature Measurement Using Infrared Spectral Band Emissions From H2O

2016 ◽  
Vol 138 (4) ◽  
Author(s):  
Daniel J. Ellis ◽  
Vladimir P. Solovjov ◽  
Dale R. Tree
Keyword(s):  
Water Vapor ◽  
Optical Measurement ◽  
Spectral Band ◽  
Combustion Products ◽  
Infrared Emission ◽  
Optical Measurements ◽  
Reactor Wall ◽  
Gas Temperature ◽  
Infrared Spectral ◽  
Gas Measurement

Currently, there is no satisfactory method for measuring the temperature of the gas phase of combustion products within a solid fuel flame. The industry standard, a suction pyrometer or aspirated thermocouple, is intrusive, spatially and temporally averaging, and difficult to use. In this work, a new method utilizing the spectral emission from water vapor is investigated through modeling and experimental measurements. The method employs the collection of infrared emission from water vapor over discrete wavelength bands and then uses the ratio of those emissions to infer temperature. This method was demonstrated in the products of a 150 kWth natural gas flame along a 0.75 m line of sight, averaged over 1 min. Results from this optical method were compared to those obtained using a suction pyrometer. Data were obtained at three fuel air equivalence ratios that produced products at three temperatures. The optical measurement produced gas temperatures approximately 3–4% higher than the suction pyrometer. The uncertainty of the optical measurements is dependent on the gas temperature being ±9% at 850 K and 4% or less above 1200 K. Broadband background emission assumed to be emitted from the reactor wall was also seen by the optical measurement and had to be removed before an accurate temperature could be measured. This complicated the gas measurement but also provides the means whereby both gas and solid emission can be measured simultaneously.

The temperature distribution along a radiating gas stream in which heat is being liberated by a chemical reaction

1951 ◽  
Vol 208 (1093) ◽  
pp. 247-262
Keyword(s):  
Heat Transfer ◽  
Heat Capacity ◽  
Heat Sink ◽  
Flame Temperature ◽  
Convection Heat Transfer ◽  
Combustion Products ◽  
Distance Curve ◽  
Fuel Jet ◽  
Initial Fuel ◽  
Fuel Stream

As a first approximation, to calculate the variation of flame temperature ( Y ) with distance ( X ) along a slowly burning flame, the flame is taken to consist of a central stream or jet of fuel which enters at the temperature ( T ) of the heat sink and entrains combustion air at a rate constant with respect to X . This entrained air is assumed to react rapidly with the fuel stream and the products of the reactions remain in the fuel stream, so that the temperature ( Y ) of the latter rises at a rate dY/dX which falls off as the heat capacity of this stream increases. When there is no heat loss from the fuel jet the temperature-distance curve is shown to be a rectangular hyperbola. The curvature at any point of the hyperbola increases as ( q ), the ratio of the heat capacity of the initial fuel stream to that of the final combustion products, decreases. In other cases heat transfer is supposed to take place by convection (α [ Y ─ T ]) orradiation (α [ Y 4 ─ T 4 ]) between the fuel jet and the heat sink with a heat-transfer coefficient which is assumed to be constant for a cylindrical flame and proportional to distance from the inlet for a conical flame. It is shown that in the case of the cylindrical flame the flame temperature must increase monotonically until combustion is complete, whereas the temperature in the conical flame can begin to fall off at an earlier stage. In the case of convection-heat transfer the shape of the temperature-distance curve is dependent only on ( q ) and on the ratio L/L 0 (where L ═ length for all combustion air to be entrained and L 0 ═ length in which all the combustion energy would be transferred to the surroundings if the flame remained at the adiabatic combustion temperature T a ). With radiative heat transfer the shape of the curves depends on ( q ) and L/L 0 but also on the ratio T/T a .

Heat capacity and cluster structure of saturated water vapor

2014 ◽  
Vol 88 (9) ◽  
pp. 1450-1455 ◽  
Author(s):  
N. P. Malomuzh ◽  
P. V. Makhlaichuk ◽  
S. V. Khrapatyi
Keyword(s):  
Heat Capacity ◽  
Water Vapor ◽  
Cluster Structure ◽  
Saturated Water Vapor ◽  
Saturated Water

Greenhouse effects of aircraft emissions as calculated by a radiative transfer model

1995 ◽  
Vol 13 (4) ◽  
pp. 413-418 ◽  
Author(s):  
J. P. F. Fortuin ◽  
R. van Dorland ◽  
W. M. F. Wauben ◽  
H. Kelder
Keyword(s):  
Water Vapor ◽  
Radiative Transfer ◽  
Indirect Effect ◽  
Radiative Forcing ◽  
Combustion Products ◽  
Ozone Production ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Aircraft Emissions ◽  
The North

Abstract. With a radiative transfer model, assessments are made of the radiative forcing in northern mid-latitudes due to aircraft emissions up to 1990. Considered are the direct climate effects from the major combustion products carbon dioxide, nitrogen dioxide, water vapor and sulphur dioxide, as well as the indirect effect of ozone production from NOx emissions. Our study indicates a local radiative forcing at the tropopause which should be negative in summer (–0.5 to 0.0 W/m2) and either negative or positive in winter (–0.3 to 0.2 W/m2). To these values the indirect effect of contrails has to be added, which for the North Atlantic Flight Corridor covers the range –0.2 to 0.3 W/m2 in summer and 0.0 to 0.3 W/m2 in winter. Apart from optically dense non-aged contrails during summer, negative forcings are due to solar screening by sulphate aerosols. The major positive contributions come from contrails, stratospheric water vapor in winter and ozone in summer. The direct effect of NO2 is negligible and the contribution of CO2 is relatively small.

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