The Experts below are selected from a list of 102 Experts worldwide ranked by ideXlab platform

Y. A. Kagramanov - One of the best experts on this subject based on the ideXlab platform.

  • Air-based coal gasification in a two-chamber gas reactor with circulating fluidized bed
    Thermal Engineering, 2017
    Co-Authors: A. M. Dubinin, V. G. Tuponogov, Y. A. Kagramanov
    Abstract:

    During the bed gasification of solid fuels, the process temperature in the reaction zone is not high enough for reaching the maximum rate of the chemical efficiency factor of the gasification process. In order to increase the chemical efficiency factor, it is necessary to supply extra heat to the reaction zone to increase the reaction temperature. In this article, coal gasification in a chamber with forced fluidized bed is considered and it is proposed to supply extra heat with a circulating flow of an inert particulate heat transfer agent. Circulating inert particulate material is successively heated by coal combustion in a cone chamber with bubbling fluidized bed and in a combustion chamber with a spherical nozzle that inhibits the forced fluidized bed. After that, the heat transfer agent heated to 930–950°C enters first in a gasification chamber with bubbling bed and then in a chamber with forced fluidized bed, where it transfers the physical heat to the air fuel mixture. The experiments conducted with crushed Borodinsky coal and inert particulate heat transfer agent (electrocorundum) showed the temperature rise in a gasification chamber with from 760 to 870°C and the increase in the Combustible Component (CO) concentration in the gasification products by 5.5%. Based on the kinetic equations of the fuel combustion reactions and the CO_2 reduction to CO and on the thermal balance equations of combustion and gasification chambers, the simulation model for the gas composition and the temperature rate calculated by the height of reaction chambers was developed. The experimental temperature rates and product gas compositions are in good agreement with the simulation results based on the proposed kinetic gasification model.

Ksenia Yu. Vershinina - One of the best experts on this subject based on the ideXlab platform.

  • Maximum combustion temperature for coal-water slurry containing petrochemicals
    Energy, 2017
    Co-Authors: Pavel A. Strizhak, Ksenia Yu. Vershinina
    Abstract:

    This study examines the temperature change of droplets of coal-water slurry containing petrochemicals (CWSP). The slurry consists of coal and oil processing waste. The temperature of oxidant in a modelled combustion chamber is varied between 600 and 1200 K. The initial size (radius) of CWSP droplets varied in the range of 0.5–3 mm. The study identifies typical temperature trends at the center and on the surface of the CWSP droplet. The temperature trends represent the following stages: (i) heating of fuel, (ii) evaporation of water and a liquid Combustible Component, (iii) thermal decomposition of coal and yield of volatiles, (iv) gas phase ignition of volatiles together with vapor of the Combustible liquid, and (v) heterogeneous ignition of carbon and its burnout. Moreover, these trends indicate the maximum combustion temperatures of CWSP that reflect corresponding heat release. The study specifies the parameters which influence the maximum combustion temperature: fuel Component composition, properties of Components, droplet size, and the oxidant temperature. Finally, the study defines the minimum ignition temperatures and delay times of sustainable combustion initiation that characterize the ignition inertia. The knowledge of influence of these factors will allow one to predict the optimal conditions for the combustion of the CWSP.

  • Variation of heating and ignition conditions for composite liquid fuel droplets on addition of dressed coal
    JP Journal of Heat and Mass Transfer, 2016
    Co-Authors: Dmitrii O Glushkov, Pavel A. Strizhak, Ksenia Yu. Vershinina
    Abstract:

    © 2016 Pushpa Publishing House, Allahabad, India. We investigate the macroscopic laws of variation of inertial heating and ignition conditions for composite liquid fuel droplets in an oxidant flow (air) by the special-purpose heating experimental equipment. Composite liquid fuel has been the conversion waste of the coal of rank K (Berezovskii field in Kemerovo region, Russia) and T (Kaltan coal pit in Kemerovo region, Russia), water, scavenge synthetic engine oil and fine particles of the dressed coal of relevant ranks. Further, we study the macroscopic laws of the inertial heating of a composite liquid fuel droplet boundary layer, thermal decomposition of the organic part, yield of volatiles and liquid Combustible Component evaporation, ignition of gaseous products and carbon residual of coal particles. Investigations demonstrate that the increase of dressed coal concentration in the composite liquid fuel leads to a significant reduction of expenses for the ignition (delay times shorten by 10-15%) of fuel composition.

Dmitrii O Glushkov - One of the best experts on this subject based on the ideXlab platform.

  • Evolution of temperature of a droplet of liquid composite fuel interacting with heated airflow
    Thermophysics and Aeromechanics, 2016
    Co-Authors: Dmitrii O Glushkov, Pavel A. Strizhak, A. V. Zakharevich, S. V. Syrodoy
    Abstract:

    The macroscopic patterns of a temperature change at the center of a droplet of three-Component (coal, water, petroleum) composite liquid fuel (CLF) were studied using a low-inertia thermoelectric converter and system of high-speed (up to 10^5 frames per second) video recording during the induction period at different heating intensity by the air flow with variable parameters: temperature of 670−870 K and motion velocity of 1−4 m/s. The studies were carried out for two groups of CLF compositions: fuel based on brown coal and coal cleaning rejects (filter cake). To assess the effect of liquid Combustible Component of CLF on characteristics of the ignition process, the corresponding composition of two-Component coal-water fuel (CWF) was studied. The stages of inert heating of CLF and CWF droplets with characteristic size corresponding to radius of 0.75−1.5 mm, evaporation of moisture and liquid oil (for CLF), thermal decomposition of the organic part of coal, gas mixture ignition, and carbon burnout were identified. Regularities of changes in the temperature of CLF and CWF droplets at each of identified stages were identified for the cooccurrence of phase transitions and chemical reactions. Comparative analysis of the times of ignition delay and complete combustion of the droplets of examined fuel compositions was performed with varying droplet dimensions, temperatures, and oxidant flow velocity.

  • Variation of heating and ignition conditions for composite liquid fuel droplets on addition of dressed coal
    JP Journal of Heat and Mass Transfer, 2016
    Co-Authors: Dmitrii O Glushkov, Pavel A. Strizhak, Ksenia Yu. Vershinina
    Abstract:

    © 2016 Pushpa Publishing House, Allahabad, India. We investigate the macroscopic laws of variation of inertial heating and ignition conditions for composite liquid fuel droplets in an oxidant flow (air) by the special-purpose heating experimental equipment. Composite liquid fuel has been the conversion waste of the coal of rank K (Berezovskii field in Kemerovo region, Russia) and T (Kaltan coal pit in Kemerovo region, Russia), water, scavenge synthetic engine oil and fine particles of the dressed coal of relevant ranks. Further, we study the macroscopic laws of the inertial heating of a composite liquid fuel droplet boundary layer, thermal decomposition of the organic part, yield of volatiles and liquid Combustible Component evaporation, ignition of gaseous products and carbon residual of coal particles. Investigations demonstrate that the increase of dressed coal concentration in the composite liquid fuel leads to a significant reduction of expenses for the ignition (delay times shorten by 10-15%) of fuel composition.

Pavel A. Strizhak - One of the best experts on this subject based on the ideXlab platform.

  • Maximum combustion temperature for coal-water slurry containing petrochemicals
    Energy, 2017
    Co-Authors: Pavel A. Strizhak, Ksenia Yu. Vershinina
    Abstract:

    This study examines the temperature change of droplets of coal-water slurry containing petrochemicals (CWSP). The slurry consists of coal and oil processing waste. The temperature of oxidant in a modelled combustion chamber is varied between 600 and 1200 K. The initial size (radius) of CWSP droplets varied in the range of 0.5–3 mm. The study identifies typical temperature trends at the center and on the surface of the CWSP droplet. The temperature trends represent the following stages: (i) heating of fuel, (ii) evaporation of water and a liquid Combustible Component, (iii) thermal decomposition of coal and yield of volatiles, (iv) gas phase ignition of volatiles together with vapor of the Combustible liquid, and (v) heterogeneous ignition of carbon and its burnout. Moreover, these trends indicate the maximum combustion temperatures of CWSP that reflect corresponding heat release. The study specifies the parameters which influence the maximum combustion temperature: fuel Component composition, properties of Components, droplet size, and the oxidant temperature. Finally, the study defines the minimum ignition temperatures and delay times of sustainable combustion initiation that characterize the ignition inertia. The knowledge of influence of these factors will allow one to predict the optimal conditions for the combustion of the CWSP.

  • Evolution of temperature of a droplet of liquid composite fuel interacting with heated airflow
    Thermophysics and Aeromechanics, 2016
    Co-Authors: Dmitrii O Glushkov, Pavel A. Strizhak, A. V. Zakharevich, S. V. Syrodoy
    Abstract:

    The macroscopic patterns of a temperature change at the center of a droplet of three-Component (coal, water, petroleum) composite liquid fuel (CLF) were studied using a low-inertia thermoelectric converter and system of high-speed (up to 10^5 frames per second) video recording during the induction period at different heating intensity by the air flow with variable parameters: temperature of 670−870 K and motion velocity of 1−4 m/s. The studies were carried out for two groups of CLF compositions: fuel based on brown coal and coal cleaning rejects (filter cake). To assess the effect of liquid Combustible Component of CLF on characteristics of the ignition process, the corresponding composition of two-Component coal-water fuel (CWF) was studied. The stages of inert heating of CLF and CWF droplets with characteristic size corresponding to radius of 0.75−1.5 mm, evaporation of moisture and liquid oil (for CLF), thermal decomposition of the organic part of coal, gas mixture ignition, and carbon burnout were identified. Regularities of changes in the temperature of CLF and CWF droplets at each of identified stages were identified for the cooccurrence of phase transitions and chemical reactions. Comparative analysis of the times of ignition delay and complete combustion of the droplets of examined fuel compositions was performed with varying droplet dimensions, temperatures, and oxidant flow velocity.

  • Variation of heating and ignition conditions for composite liquid fuel droplets on addition of dressed coal
    JP Journal of Heat and Mass Transfer, 2016
    Co-Authors: Dmitrii O Glushkov, Pavel A. Strizhak, Ksenia Yu. Vershinina
    Abstract:

    © 2016 Pushpa Publishing House, Allahabad, India. We investigate the macroscopic laws of variation of inertial heating and ignition conditions for composite liquid fuel droplets in an oxidant flow (air) by the special-purpose heating experimental equipment. Composite liquid fuel has been the conversion waste of the coal of rank K (Berezovskii field in Kemerovo region, Russia) and T (Kaltan coal pit in Kemerovo region, Russia), water, scavenge synthetic engine oil and fine particles of the dressed coal of relevant ranks. Further, we study the macroscopic laws of the inertial heating of a composite liquid fuel droplet boundary layer, thermal decomposition of the organic part, yield of volatiles and liquid Combustible Component evaporation, ignition of gaseous products and carbon residual of coal particles. Investigations demonstrate that the increase of dressed coal concentration in the composite liquid fuel leads to a significant reduction of expenses for the ignition (delay times shorten by 10-15%) of fuel composition.

A. M. Dubinin - One of the best experts on this subject based on the ideXlab platform.

  • Air-based coal gasification in a two-chamber gas reactor with circulating fluidized bed
    Thermal Engineering, 2017
    Co-Authors: A. M. Dubinin, V. G. Tuponogov, Y. A. Kagramanov
    Abstract:

    During the bed gasification of solid fuels, the process temperature in the reaction zone is not high enough for reaching the maximum rate of the chemical efficiency factor of the gasification process. In order to increase the chemical efficiency factor, it is necessary to supply extra heat to the reaction zone to increase the reaction temperature. In this article, coal gasification in a chamber with forced fluidized bed is considered and it is proposed to supply extra heat with a circulating flow of an inert particulate heat transfer agent. Circulating inert particulate material is successively heated by coal combustion in a cone chamber with bubbling fluidized bed and in a combustion chamber with a spherical nozzle that inhibits the forced fluidized bed. After that, the heat transfer agent heated to 930–950°C enters first in a gasification chamber with bubbling bed and then in a chamber with forced fluidized bed, where it transfers the physical heat to the air fuel mixture. The experiments conducted with crushed Borodinsky coal and inert particulate heat transfer agent (electrocorundum) showed the temperature rise in a gasification chamber with from 760 to 870°C and the increase in the Combustible Component (CO) concentration in the gasification products by 5.5%. Based on the kinetic equations of the fuel combustion reactions and the CO_2 reduction to CO and on the thermal balance equations of combustion and gasification chambers, the simulation model for the gas composition and the temperature rate calculated by the height of reaction chambers was developed. The experimental temperature rates and product gas compositions are in good agreement with the simulation results based on the proposed kinetic gasification model.