Igor Hudák - Academia.edu (original) (raw)
Papers by Igor Hudák
Vysoké učení technické v Brně. Fakulta strojního inženýrství, Jun 21, 2010
Sustainability
A rotary kiln is a unique facility with widespread applications not only in the process industry,... more A rotary kiln is a unique facility with widespread applications not only in the process industry, such as building-material production, but also in the energy sector. There is a lack of a more comprehensive review of this facility and its perspectives in the literature. This paper gives a semi-systematic review of current research. Main trends and solutions close to commercial applications are found and evaluated. The overlap between process and energy engineering brings the opportunity to find various uncommon applications. An example is a biogas plant digestate treatment using pyrolysis in the rotary kiln. Artificial intelligence also finds its role in rotary kiln control processes. The most significant trend within rotary kiln research is the waste-to-energy approach in terms of various waste utilization within the process industry or waste pyrolysis in terms of new alternative fuel production and material utilization. Results from this review could open new perspectives for furt...
The dissertation thesis is focused on the investigation of the influence of inert gases on charac... more The dissertation thesis is focused on the investigation of the influence of inert gases on characteristic parameters of the combustion process. Inert gases are usually standard components of alternative gaseous fuels such as the producer gas, coal gas or biogas. For a long period some of the fuels were considered as waste gases and their potential was not sufficiently utilised. Compared with noble fuels such as natural gas, alternative fuels have different physical-chemical properties. For example, their lower heating value (LHV) can be lower even than 10 MJ/mN3. The composition of the alternative gaseous fuels can be various during their production process. Lower LHV is a result of the occurrence of inert gases that does not take a part in the combustion reactions. Inert gases have the ability to accumulate the heat. Under certain conditions it is possible to combust alternative fuels on conventional burners, but due to their different properties, problems can occur during the comb...
Energies
The objective of the present study was to experimentally investigate and compare the characterist... more The objective of the present study was to experimentally investigate and compare the characteristics of three oxygen-enhanced combustion (OEC) methods; premix enrichment (PE), air-oxy/fuel combustion (AO), and additionally also oxygen lancing (OL) method. The overall oxygen concentration varied from 21% to 38%. Combustion tests were carried out using the gas burner with the thermal input of 750 kW fired by natural gas. The characteristics of OEC methods, such as the concentration of nitrogen oxides and carbon monoxide in flue gas, in-flame temperatures distribution in the horizontal symmetry plane of the combustion chamber, heat flux to the combustion chamber wall, flue gas temperature, and the stability of flame were investigated. NOx emissions increased by more than 40 times and by 20 times for the PE method. The tests using the AO and OL methods with NOx emissions below 150 mg/Nm3 at all oxygen concentrations showed significantly better results. For all OEC methods, radiative hea...
Energies, 2021
To describe the effects of inert compounds in gaseous fuel, experiments on three different proces... more To describe the effects of inert compounds in gaseous fuel, experiments on three different process burners (staged fuel burner, staged air burner, and low-calorific burner) were carried out. The tested burners are commercially available, but they were specially designed for experimental usage. Tests were carried out in the semi-industrial burner testing facility to investigate the influence of inert gases on the flame characteristics, emissions, and heat flux to the combustion chamber wall. Natural gas was used as a reference fuel, and, during all tests, thermal power of 500 kW was maintained. To simulate the combustion of alternative fuels with lower LHV, N2 and CO2 were used as diluents. The inert gas in the hydrocarbon fuel at certain conditions can lower NOx emissions (up to 80%) and increase heat flux (up to 5%). Once incombustible compounds are present in the fuel, the higher amount of fuel flowing through nozzles affects the flow in the combustion chamber by increasing the Re...
The thesis is focused on the investigation of oxygen enhanced combustion (OEC) and its impact on ... more The thesis is focused on the investigation of oxygen enhanced combustion (OEC) and its impact on the burner characteristics. The OEC technology is used in various industrial applications, in which increased productivity, higher heat efficiency, improved flame characteristics, reduced equipment cost and/or improved product quality is required. However, the application of OEC technology can also cause problems such as refractory damage, nonuniform heating, flame disturbance, increased pollutant emission and/or flashback. The experiments were carried out at the burner testing facility that enables to test different types of burners (gaseous, liquid or combined) up to the thermal input 1 800 kW. During the tests two staged low-NO x burner fired by natural gas was used. The work was aimed at the studying of the influence of 21-46 % oxygen concentration on the NO x emissions, the flue gas temperature, the distribution of the heat extracted from the hot flue gas to the wall of the combustion chamber, and the flame pattern including its stability, shape and dimensions. The combustion tests of premixed air and air-oxy/fuel methods were carried out at the thermal inputs of 300 kW, 500 kW and 750 kW for two combustion modesone staged combustion and two staged combustion.
Energy, 2014
ABSTRACT This study was focused on the experimental investigation of the very promising combustio... more ABSTRACT This study was focused on the experimental investigation of the very promising combustion technology called as the oxygen-enhanced combustion (OEC), which uses the oxidant containing higher proportion of oxygen than in the atmospheric air, i.e. more than 21%. The work investigated and compared the characteristics of two OEC methods, namely the premix enrichment and air-oxy/fuel combustion, when the overall oxygen concentration was varied from 21% to 46%. The combustion tests were performed with the experimental two-gas-staged burner of low-NOx type at the burner thermal input of 750 kW for two combustion regimes – one-staged and two-staged combustion. The oxygen concentration in the flue gas was maintained in the neighborhood of 3% vol. (on dry basis). The aim of tests was to assess the impact of the oxidant composition, type of OEC method and fuel-staging on the characteristic combustion parameters in detail. The investigated parameters included the concentration of nitrogen oxides (NOx) in the flue gas, flue gas temperature, heat flux to the combustion chamber wall, and lastly the stability, shape and dimensions of flame. It was observed that NOx emission is significantly lower when the air-oxy/fuel method is used compared to the premix enrichment method. Moreover, when the fuel was staged, NOx emission was below 120 mg/Nm3 at all investigated oxygen flow rates. Increasing oxygen concentration resulted in higher heating intensity due to higher concentrations of CO2 and H2O. The available heat at 46% O2 was higher by 20% compared with that at 21% O2.
Vysoké učení technické v Brně. Fakulta strojního inženýrství, Jun 21, 2010
Sustainability
A rotary kiln is a unique facility with widespread applications not only in the process industry,... more A rotary kiln is a unique facility with widespread applications not only in the process industry, such as building-material production, but also in the energy sector. There is a lack of a more comprehensive review of this facility and its perspectives in the literature. This paper gives a semi-systematic review of current research. Main trends and solutions close to commercial applications are found and evaluated. The overlap between process and energy engineering brings the opportunity to find various uncommon applications. An example is a biogas plant digestate treatment using pyrolysis in the rotary kiln. Artificial intelligence also finds its role in rotary kiln control processes. The most significant trend within rotary kiln research is the waste-to-energy approach in terms of various waste utilization within the process industry or waste pyrolysis in terms of new alternative fuel production and material utilization. Results from this review could open new perspectives for furt...
The dissertation thesis is focused on the investigation of the influence of inert gases on charac... more The dissertation thesis is focused on the investigation of the influence of inert gases on characteristic parameters of the combustion process. Inert gases are usually standard components of alternative gaseous fuels such as the producer gas, coal gas or biogas. For a long period some of the fuels were considered as waste gases and their potential was not sufficiently utilised. Compared with noble fuels such as natural gas, alternative fuels have different physical-chemical properties. For example, their lower heating value (LHV) can be lower even than 10 MJ/mN3. The composition of the alternative gaseous fuels can be various during their production process. Lower LHV is a result of the occurrence of inert gases that does not take a part in the combustion reactions. Inert gases have the ability to accumulate the heat. Under certain conditions it is possible to combust alternative fuels on conventional burners, but due to their different properties, problems can occur during the comb...
Energies
The objective of the present study was to experimentally investigate and compare the characterist... more The objective of the present study was to experimentally investigate and compare the characteristics of three oxygen-enhanced combustion (OEC) methods; premix enrichment (PE), air-oxy/fuel combustion (AO), and additionally also oxygen lancing (OL) method. The overall oxygen concentration varied from 21% to 38%. Combustion tests were carried out using the gas burner with the thermal input of 750 kW fired by natural gas. The characteristics of OEC methods, such as the concentration of nitrogen oxides and carbon monoxide in flue gas, in-flame temperatures distribution in the horizontal symmetry plane of the combustion chamber, heat flux to the combustion chamber wall, flue gas temperature, and the stability of flame were investigated. NOx emissions increased by more than 40 times and by 20 times for the PE method. The tests using the AO and OL methods with NOx emissions below 150 mg/Nm3 at all oxygen concentrations showed significantly better results. For all OEC methods, radiative hea...
Energies, 2021
To describe the effects of inert compounds in gaseous fuel, experiments on three different proces... more To describe the effects of inert compounds in gaseous fuel, experiments on three different process burners (staged fuel burner, staged air burner, and low-calorific burner) were carried out. The tested burners are commercially available, but they were specially designed for experimental usage. Tests were carried out in the semi-industrial burner testing facility to investigate the influence of inert gases on the flame characteristics, emissions, and heat flux to the combustion chamber wall. Natural gas was used as a reference fuel, and, during all tests, thermal power of 500 kW was maintained. To simulate the combustion of alternative fuels with lower LHV, N2 and CO2 were used as diluents. The inert gas in the hydrocarbon fuel at certain conditions can lower NOx emissions (up to 80%) and increase heat flux (up to 5%). Once incombustible compounds are present in the fuel, the higher amount of fuel flowing through nozzles affects the flow in the combustion chamber by increasing the Re...
The thesis is focused on the investigation of oxygen enhanced combustion (OEC) and its impact on ... more The thesis is focused on the investigation of oxygen enhanced combustion (OEC) and its impact on the burner characteristics. The OEC technology is used in various industrial applications, in which increased productivity, higher heat efficiency, improved flame characteristics, reduced equipment cost and/or improved product quality is required. However, the application of OEC technology can also cause problems such as refractory damage, nonuniform heating, flame disturbance, increased pollutant emission and/or flashback. The experiments were carried out at the burner testing facility that enables to test different types of burners (gaseous, liquid or combined) up to the thermal input 1 800 kW. During the tests two staged low-NO x burner fired by natural gas was used. The work was aimed at the studying of the influence of 21-46 % oxygen concentration on the NO x emissions, the flue gas temperature, the distribution of the heat extracted from the hot flue gas to the wall of the combustion chamber, and the flame pattern including its stability, shape and dimensions. The combustion tests of premixed air and air-oxy/fuel methods were carried out at the thermal inputs of 300 kW, 500 kW and 750 kW for two combustion modesone staged combustion and two staged combustion.
Energy, 2014
ABSTRACT This study was focused on the experimental investigation of the very promising combustio... more ABSTRACT This study was focused on the experimental investigation of the very promising combustion technology called as the oxygen-enhanced combustion (OEC), which uses the oxidant containing higher proportion of oxygen than in the atmospheric air, i.e. more than 21%. The work investigated and compared the characteristics of two OEC methods, namely the premix enrichment and air-oxy/fuel combustion, when the overall oxygen concentration was varied from 21% to 46%. The combustion tests were performed with the experimental two-gas-staged burner of low-NOx type at the burner thermal input of 750 kW for two combustion regimes – one-staged and two-staged combustion. The oxygen concentration in the flue gas was maintained in the neighborhood of 3% vol. (on dry basis). The aim of tests was to assess the impact of the oxidant composition, type of OEC method and fuel-staging on the characteristic combustion parameters in detail. The investigated parameters included the concentration of nitrogen oxides (NOx) in the flue gas, flue gas temperature, heat flux to the combustion chamber wall, and lastly the stability, shape and dimensions of flame. It was observed that NOx emission is significantly lower when the air-oxy/fuel method is used compared to the premix enrichment method. Moreover, when the fuel was staged, NOx emission was below 120 mg/Nm3 at all investigated oxygen flow rates. Increasing oxygen concentration resulted in higher heating intensity due to higher concentrations of CO2 and H2O. The available heat at 46% O2 was higher by 20% compared with that at 21% O2.