The Manifold Problem

1949 ◽  
Vol 16 (1) ◽  
pp. 77-85
Author(s):  
J. D. Keller

Abstract This paper deals with the general problem of manifolds supplying fluids to a set of parallel pipes or ducts, or discharging through numerous openings distributed along the manifold length. Examples are the familiar “pipe burner” for gaseous fuels; the manifold of the “radiant-fire” type of gas burner; headers or manifolds for certain types of multitube air heaters; the distributing flues above and below the checkers of open-hearth furnaces and of glass tanks; furnace combustion chambers containing heat ports; distributing pipes in water-filtering systems; and many others. The very specialized problem of the gasoline-engine manifold is not considered here.

2020 ◽  
pp. 302-302
Author(s):  
Aleksandar Milivojevic ◽  
Miroljub Adzic ◽  
Milan Gojak ◽  
Mirjana Stamenic ◽  
Vuk Adzic

The paper presents results of theoretical numerical research dealing with CO and NOX emission performed in the process of optimization of the performance of low-power atmospheric burners. The theoretical part of this paper, whose main goals were better understanding of the complex issues of methodology and establishment of performance prediction and optimization of low-power atmospheric gas burner included numerical variation of independent parameters, such as burner geometry, the coefficients of primary and secondary air and different gaseous fuels including biogas. The findings of theoretically obtained performance prediction and optimization of atmospheric burners were experimentally investigated in purpose built test rigs for a number of variable parameters. The obtained results fully justified the proposed models of performance prediction and burner optimization.


Author(s):  
A. K. Malkogianni ◽  
A. Tourlidakis ◽  
A. L. Polyzakis

Coal gas and biofuels as alternative fuels have recently become more attractive, because of their benefits, especially in electrical power industry. The major obstruction to their use is the relatively low calorific values. This paper presents a comprehensive simulation method for calculating the adiabatic temperature of various fuels when they are used in combustion chambers under constant pressure. The adiabatic temperature is presented as a function of combustion fuel air ratios and the fuels low calorific values. In addition, the utilization of various gaseous fuels in single shaft and two shaft gas turbine engines is analyzed. This analysis includes the design point (DP) and off-design (OD) performance of the two engines. The calorific values of the four gases investigated correspond to natural gas (NG) and to fuels with significantly lower calorific values than that of NG (coal synthetic gases, biofuels). Two main conclusions are drawn from this analysis. Firstly, for both single shaft and two shaft engines and for a given turbine entry temperature (TET), both power and thermal efficiency are increasing when fuels with decreasing calorific value are burnt. Secondly, for both single shaft and two shaft engines and for a given power, the thermal efficiency is slightly reduced.


1977 ◽  
Vol 36 ◽  
pp. 143-180 ◽  
Author(s):  
J.O. Stenflo

It is well-known that solar activity is basically caused by the Interaction of magnetic fields with convection and solar rotation, resulting in a great variety of dynamic phenomena, like flares, surges, sunspots, prominences, etc. Many conferences have been devoted to solar activity, including the role of magnetic fields. Similar attention has not been paid to the role of magnetic fields for the overall dynamics and energy balance of the solar atmosphere, related to the general problem of chromospheric and coronal heating. To penetrate this problem we have to focus our attention more on the physical conditions in the ‘quiet’ regions than on the conspicuous phenomena in active regions.


Author(s):  
O. M. Salamov ◽  
F. F. Aliyev

The paper discusses the possibility of obtaining liquid and gaseous fuels from different types of biomass (BM) and combustible solid waste (CSW) of various origins. The available world reserves of traditional types of fuel are analyzed and a number of environmental shortcomings that created during their use are indicated. The tables present the data on the conditional calorific value (CCV) of the main traditional and alternative types of solid, liquid and gaseous fuels which compared with CCV of various types of BM and CSW. Possible methods for utilization of BM and CSW are analyzed, as well as the methods for converting them into alternative types of fuel, especially into combustible gases.Reliable information is given on the available oil and gas reserves in Azerbaijan. As a result of the research, it was revealed that the currently available oil reserves of Azerbaijan can completely dry out after 33.5 years, and gas reserves–after 117 years, without taking into account the growth rates of the exported part of these fuels to European countries. In order to fix this situation, first of all it is necessary to use as much as possible alternative and renewable energy sources, especially wind power plants (WPP) and solar photovoltaic energy sources (SFES) in the energy sector of the republic. Azerbaijan has large reserves of solar and wind energy. In addition, all regions of the country have large reserves of BM, and in the big cities, especially in industrial ones, there are CSW from which through pyrolysis and gasification is possible to obtain a high-quality combustible gas mixture, comprising: H2 + CO + CH4, with the least amount of harmful waste. The remains of the reaction of thermochemical decomposition of BM and CSW to combustible gases can also be used as mineral fertilizers in agriculture. The available and projected resources of Azerbaijan for the BM and the CSW are given, as well as their assumed energy intensity in the energy sector of the republic.Given the high energy intensity of the pyrolysis and gasification of the BM and CSW, at the present time for carrying out these reactions, the high-temperature solar installations with limited power are used as energy sources, and further preference is given to the use of WPP and SFES on industrial scale.


2017 ◽  
Vol 9 (1) ◽  
pp. 147-162
Author(s):  
Jeremy W. Skrzypek

It is often suggested that, since the state of affairs in which God creates a good universe is better than the state of affairs in which He creates nothing, a perfectly good God would have to create that good universe. Making use of recent work by Christine Korgaard on the relational nature of the good, I argue that the state of affairs in which God creates is actually not better, due to the fact that it is not better for anyone or anything in particular. Hence, even a perfectly good God would not be compelled to create a good universe.


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