scholarly journals Use of waste material mixtures for energy purposes in small combustion devices

2014 ◽  
Vol 60 (No. 2) ◽  
pp. 50-59 ◽  
Author(s):  
J. Malaťák ◽  
J. Bradna

The article assesses the energy use of solid biofuels (wheat and rape straw) and their blends with suitable additives (cocoa husks, brown coal and coal sludge). The elemental and stoichiometric analysis evaluates their suitability for energy recovery. Furthermore, thermal emission characteristics in automatic hot water boiler VERNER A251 are observed. The results of thermal emission measurements show that all samples meet the requirements of the Directive No. 13/2006 for carbon monoxide (2,000 mg/m<sup>3</sup>). The average nitrogen oxides emission concentrations exceed emission limits compared with the Directive No. 13/2006 (250 mg/m<sup>3</sup>) for all samples of solid biofuels. One reason is the high temperature in the combustion chamber that increases combustion temperature and results in high temperature of nitrogen oxides. Another problem is carbon monoxide that depends on the coefficient of excess air. The value of this coefficient drops under its optimum (2.5) and subsequently follows an increasing trend. &nbsp;

1983 ◽  
Vol 30 ◽  
Author(s):  
F. W. Giacobbe ◽  
D. W. Schmerling

ABSTRACTA unique and efficient plasma jet reactor has been developed and used to study the high temperature production of carbon monoxide from a reaction between powdered carbon and a pure carbon dioxide plasma. The plasma jet reactor was designed to allow the injection of powdered carbon above the arc discharge region rather than into the plasma flame below the arc discharge region. High yields of carbon monoxide, produced at relatively high efficiencies, were a direct result of this technique. The plasma jet was also designed to enable rapid changing and testing of various anode insertsAverage yields of carbon monoxide in the product gases were as high as 80–87% in selected experimental trials. Carbon monoxide was produced at rates exceeding 15,000 1/hr (at STP) with a power expenditure of 52 Kw.


2020 ◽  
Vol 0 (10) ◽  
pp. 35-40
Author(s):  
S.I. Gertsyk ◽  
◽  
I.V. Belyakov ◽  

The formation probability of nitrogen oxides in combustion products of mixed blast-furnace and natural gases under different conditions of combustion was calculated. It has been found out that heating the air incoming into burners of high-temperature blast-furnaces sharply increases concentration of nitrogen oxides in combustion products (by 1.5-1.75 times). It was notices that in furnaces where temperature was less than 950-1000 °С, heating the air up to 400 °С increased NOx content in gases released to the atmosphere no more than by 20-23%, and oxide concentration was in limits of sanitary standards.


2021 ◽  
pp. 28-32
Author(s):  
VALERIY L. CHUMAKOV ◽  

The paper shows some ways to improve the environmental characteristics of a diesel engine using gaseous hydrocarbon fuel and operating the engine in a gas-diesel cycle mode. Some possibilities to reduce toxic components of exhaust gases in a gas-diesel engine operating on liquefi ed propane-butane mixtures have been studied. Experiments carried out in a wide range of load from 10 to 100% and speed from 1400 to 2000 rpm showed that the gas-diesel engine provides a suffi ciently high level of diesel fuel replacement with gas hydrocarbon fuel. The authors indicate some eff ective ways to reduce the toxicity of exhaust gases. The engine power should be adjusted by the simultaneous supply of fuel, gas and throttling the air charge in the intake manifold. This method enriches the fi rst combusting portions to reduce nitrogen oxides and maintains the depletion of the main charge within the fl ammability limits of the gas-air charge to reduce carbon monoxide and hydrocarbons. The authors found that when the engine operates in a gas-diesel cycle mode, the power change provides a decrease in nitrogen oxide emissions of gas-diesel fuel only due to gas supply in almost the entire load range as compared to the pure diesel. At high loads (more than 80%) stable engine operation is ensured up to 90% of diesel fuel replaced by gas. Even at 10% of diesel fuel used the concentration of nitrogen oxides decreases by at least 15…20% as compared with a diesel engine in the entire load range. However, there is an increased emission of hydrocarbons and carbon monoxide in the exhaust gases. Further experimental studies have shown that optimization of the gas diesel regulation can reduce the mass emission of nitrogen oxides contained in exhaust gases in 2…3 times and greatly reduce the emission of incomplete combustion products – carbon monoxide and hydrocarbons.


Author(s):  
Ali Afrazeh ◽  
Hiwa Khaledi ◽  
Mohammad Bagher Ghofrani

A gas turbine in combination with a nuclear heat source has been subject of study for some years. This paper describes the advantages of a gas turbine combined with an inherently safe and well-proven nuclear heat source. The design of the power conversion system is based on a regenerative, non-intercooled, closed, direct Brayton cycle with high temperature gas-cooled reactor (HTGR), as heat source and helium gas as the working fluid. The plant produces electricity and hot water for district heating (DH). Variation of specific heat, enthalpy and entropy of working fluid with pressure and temperature are included in this model. Advanced blade cooling technology is used in order to allow for a high turbine inlet temperature. The paper starts with an overview of the main characteristics of the nuclear heat source, Then presents a study to determine the specifications of a closed-cycle gas turbine for the HTGR installation. Attention is given to the way such a closed-cycle gas turbine can be modeled. Subsequently the sensitivity of the efficiency to several design choices is investigated. This model is developed in Fortran.


2018 ◽  
Vol 44 ◽  
pp. 00056 ◽  
Author(s):  
Sylwia Janta-Lipińska ◽  
Alexander Shkarovskiy

Nitrogen oxides are considered to be much more toxic than, for example, carbon monoxide. For this reason, the Authors developed and implemented a method for decrease of NOX emission into the atmosphere from DKVR 10-13 boilers. As an effective method for boilers propose injection of steam into the combustion zone. After series of experimental studies an optimal design of the head for steam injection was developed, according to the proprietary technology. The injector head was kept unchanged while the spraying end caps were modified (Fig. 2). Three levels of possible impact of emissions from boiler on the atmosphere pollution were taken into account during studies. After the analysis, it was assumed that the level of the real maximum emission should be taken as the reference level in relation to which the decrease of NOX emission should be determined. The results obtained by the Authors calculated into mass emission and as objective values of nitrogen oxides concentration calculated into α = 1 (Figures 3 and 4). Realization of the study plan, assumed by the Authors, allowed to determine the optimal parameters of the NOx emission decrease method, assuming the expected 30% level of emission decrease at a limited consumption of injected.


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