Tingguang Ma | Oklahoma State University (original) (raw)
Papers by Tingguang Ma
Ignitability and Explosibility of Gases and Vapors, 2015
Ignitability and Explosibility of Gases and Vapors, 2015
Ignitability and Explosibility of Gases and Vapors, 2015
Ignitability and Explosibility of Gases and Vapors, 2015
Ignitability and Explosibility of Gases and Vapors, 2015
Ignitability and Explosibility of Gases and Vapors, 2015
Ignitability and Explosibility of Gases and Vapors, 2015
Ignitability and Explosibility of Gases and Vapors, 2015
Fire Technology, 2014
ABSTRACT Background One of the challenges in controlling an underground coal mine fire is that it... more ABSTRACT Background One of the challenges in controlling an underground coal mine fire is that it is fully sealed with limited information available through gas sampling. Most of previous works look at the fuel content of the mixture, or the explosibility. Here we are proposing a progress variable to check both fuel and oxygen for diagnosing what is the status of fire after sealing, and when the sealed atmosphere is explosive if a leaking is allowed.In essence, the flammability problem of mine gases is a mixture problem of multiple fuels, with carbon dioxide as the diluent, in an oxygen-modified air [1]. In order to determine the status of a sealed fire, a progress variable, heating/quenching ratio, is proposed as the completion between heating and quenching, whereas heating can be oxygen-based or fuel-based. ...
Ignitability and Explosibility of Gases and Vapors, 2015
Process Safety Progress, 2012
The Incident Command System (ICS) is a standardized approach typically structured into five funct... more The Incident Command System (ICS) is a standardized approach typically structured into five functional areas: command, operations, planning, logistics, and finance. The system allows for the integration of personnel, facilities, equipment, procedures, and communications within an organizational structure. It is a mature system and has been used by industries for a long time to aid in the proper mitigation of industrial incidents. The course named ''Hazardous Materials Incident Management'' is taught in the Department of Fire Protection & Safety at Oklahoma State University, which is designed to prepare students to manage hazardous materials emergencies through extensive hands-on trainings. This article shows three design scenarios and how the ICS procedures are applied by student teams during the field trainings. Emergency response can be safely and effectively accomplished only when procedures are established and standardized through appropriate training. The discussion will help the academia and industry to well prepare/train the next generation of both public and private sector emergency response personnel.
Recently, a thermal method was proposed to recheck the concept of flammability by manipulating th... more Recently, a thermal method was proposed to recheck the concept of flammability by manipulating the competition between heating and quenching. This method is further explored here to reconstruct flammability diagrams, explaining the contribution of each component toward flammability change for a mixture. Based on the assumption that a diluent will not change the flame temperature at the flammability limits, these isothermal processes lead to a conservative estimation of the flammable zone. Although rough near the inertion point, the theoretical flammability envelop has the potential to guide future purging and diluting operations. It will be a powerful tool for both educational purposes and practical utilities.
A generic method is proposed to use the flammability diagram to determine the flammable state of ... more A generic method is proposed to use the flammability diagram to determine the flammable state of a mixture and the dilution requirements. All graphs are derived from theory, without any empirical constants. This method is comprehensive and consistent with a same treatment for fuel(s)/oxidizer(s)/diluent(s). The theoretical LFL lines are generally lower than the experimental lines due to the assumption on constant flame temperature. So, the prediction is usually conservative, which is good for estimation purposes.
Flammability diagrams are frequently used for guiding dilution and purge operations. Here Jones d... more Flammability diagrams are frequently used for guiding dilution and purge operations. Here Jones diluted flammability diagram is further developed to include the theoretical envelope and analytical dilution/purge lines. A thermal explanation is provided for this theoretical flammability diagram. With theoretical dilution/purge curves, this diagram provide the same results as those from Zabetakis tertiary diagram. Comparing with experimental diagram, this theoretical approach is more conservative and has the advantages of flexibility on various fuel/diluents. Practical problems are solved to demonstrate the utility and the equivalency with existing tertiary diagrams. It will be an important tool for guiding both educational and industrial practices.
Out of the thermal balance method, a method of presenting mine fire data is proposed in this work... more Out of the thermal balance method, a method of presenting mine fire data is proposed in this work. By grouping fuels into a pseudo fuel, grouping nitrogen and oxygen into a pseudo air, and using carbon dioxide as the diluent, a diluted flammability diagram is reconstructed for this oxygen-modified environment. The flammability envelop is controlled by oxygen availability, while the operation point is controlled by fuel/diluent availability. The relative position between the envelop and the operation point shows the flammable state of this mixture. Coward's explosive triangle is also applied using the limiting oxygen concentration derived from the diagram. Both are most useful in guiding the suppression operation for an underground coal mine fire.
Starting from the flammability diagram, a thermal theory is proposed to scale various critical co... more Starting from the flammability diagram, a thermal theory is proposed to scale various critical concentrations in combustion. By an analogy between ignition and suppression, the flammability limits are extrapolated to minimum extinguishing concentrations. Thus the suppressibility of a fuel will be evaluated from its flammability, while the suppression capability of an agent will be evaluated using the cupburner (CB) value. By setting up the thermal balance at extinguishing, the synergistic effect can also be explained by an adjustable flame temperature factor. This thermal mechanism will guide the future work on selecting new combinations of binary agents.
and sharing with colleagues.
The objective of this work was to determine the accuracy and limitations of a new version of Fire... more The objective of this work was to determine the accuracy and limitations of a new version of Fire Dynamics Simulator (FDS), developed by McGrattan et al., on axi-symmetric fire plumes. The current version uses LES for turbulence, a mixture-fraction-based infinitely fast chemistry model for combustion, and a constant radiative loss fraction. These sub-models have been tested for unconfined fires of different sizes, based on a dimensionless heat release rate Q Ã D in the range of 0.1 to 10.0, which covers most natural fire scenarios. No adjustment of constants or algorithms in the model FDS2.0 have been made. An examination of plume theory is made first to find the benchmark correlations. This shows a generalization for a collection of correlations based on theory, and which might be ''the best''. Using the characteristic length as the scaling factor, it is found that the optimum resolution of a pool fire simulation is around 0.05. With this resolution, the flame height prediction is found to fit well with flame height correlations. Some other parameters such as temperature and mixture fraction are found to be close to the empirical estimations at flame tips. The Froude number, which describes the relative strength of momentum and buoyancy, falls within the measurement range of many researchers. The simulation also reveals that the temperature near the burner is over-predicted, while the centerline temperature and velocity in the noncombusting region is predicted well. r
Ignitability and Explosibility of Gases and Vapors, 2015
Ignitability and Explosibility of Gases and Vapors, 2015
Ignitability and Explosibility of Gases and Vapors, 2015
Ignitability and Explosibility of Gases and Vapors, 2015
Ignitability and Explosibility of Gases and Vapors, 2015
Ignitability and Explosibility of Gases and Vapors, 2015
Ignitability and Explosibility of Gases and Vapors, 2015
Ignitability and Explosibility of Gases and Vapors, 2015
Fire Technology, 2014
ABSTRACT Background One of the challenges in controlling an underground coal mine fire is that it... more ABSTRACT Background One of the challenges in controlling an underground coal mine fire is that it is fully sealed with limited information available through gas sampling. Most of previous works look at the fuel content of the mixture, or the explosibility. Here we are proposing a progress variable to check both fuel and oxygen for diagnosing what is the status of fire after sealing, and when the sealed atmosphere is explosive if a leaking is allowed.In essence, the flammability problem of mine gases is a mixture problem of multiple fuels, with carbon dioxide as the diluent, in an oxygen-modified air [1]. In order to determine the status of a sealed fire, a progress variable, heating/quenching ratio, is proposed as the completion between heating and quenching, whereas heating can be oxygen-based or fuel-based. ...
Ignitability and Explosibility of Gases and Vapors, 2015
Process Safety Progress, 2012
The Incident Command System (ICS) is a standardized approach typically structured into five funct... more The Incident Command System (ICS) is a standardized approach typically structured into five functional areas: command, operations, planning, logistics, and finance. The system allows for the integration of personnel, facilities, equipment, procedures, and communications within an organizational structure. It is a mature system and has been used by industries for a long time to aid in the proper mitigation of industrial incidents. The course named ''Hazardous Materials Incident Management'' is taught in the Department of Fire Protection & Safety at Oklahoma State University, which is designed to prepare students to manage hazardous materials emergencies through extensive hands-on trainings. This article shows three design scenarios and how the ICS procedures are applied by student teams during the field trainings. Emergency response can be safely and effectively accomplished only when procedures are established and standardized through appropriate training. The discussion will help the academia and industry to well prepare/train the next generation of both public and private sector emergency response personnel.
Recently, a thermal method was proposed to recheck the concept of flammability by manipulating th... more Recently, a thermal method was proposed to recheck the concept of flammability by manipulating the competition between heating and quenching. This method is further explored here to reconstruct flammability diagrams, explaining the contribution of each component toward flammability change for a mixture. Based on the assumption that a diluent will not change the flame temperature at the flammability limits, these isothermal processes lead to a conservative estimation of the flammable zone. Although rough near the inertion point, the theoretical flammability envelop has the potential to guide future purging and diluting operations. It will be a powerful tool for both educational purposes and practical utilities.
A generic method is proposed to use the flammability diagram to determine the flammable state of ... more A generic method is proposed to use the flammability diagram to determine the flammable state of a mixture and the dilution requirements. All graphs are derived from theory, without any empirical constants. This method is comprehensive and consistent with a same treatment for fuel(s)/oxidizer(s)/diluent(s). The theoretical LFL lines are generally lower than the experimental lines due to the assumption on constant flame temperature. So, the prediction is usually conservative, which is good for estimation purposes.
Flammability diagrams are frequently used for guiding dilution and purge operations. Here Jones d... more Flammability diagrams are frequently used for guiding dilution and purge operations. Here Jones diluted flammability diagram is further developed to include the theoretical envelope and analytical dilution/purge lines. A thermal explanation is provided for this theoretical flammability diagram. With theoretical dilution/purge curves, this diagram provide the same results as those from Zabetakis tertiary diagram. Comparing with experimental diagram, this theoretical approach is more conservative and has the advantages of flexibility on various fuel/diluents. Practical problems are solved to demonstrate the utility and the equivalency with existing tertiary diagrams. It will be an important tool for guiding both educational and industrial practices.
Out of the thermal balance method, a method of presenting mine fire data is proposed in this work... more Out of the thermal balance method, a method of presenting mine fire data is proposed in this work. By grouping fuels into a pseudo fuel, grouping nitrogen and oxygen into a pseudo air, and using carbon dioxide as the diluent, a diluted flammability diagram is reconstructed for this oxygen-modified environment. The flammability envelop is controlled by oxygen availability, while the operation point is controlled by fuel/diluent availability. The relative position between the envelop and the operation point shows the flammable state of this mixture. Coward's explosive triangle is also applied using the limiting oxygen concentration derived from the diagram. Both are most useful in guiding the suppression operation for an underground coal mine fire.
Starting from the flammability diagram, a thermal theory is proposed to scale various critical co... more Starting from the flammability diagram, a thermal theory is proposed to scale various critical concentrations in combustion. By an analogy between ignition and suppression, the flammability limits are extrapolated to minimum extinguishing concentrations. Thus the suppressibility of a fuel will be evaluated from its flammability, while the suppression capability of an agent will be evaluated using the cupburner (CB) value. By setting up the thermal balance at extinguishing, the synergistic effect can also be explained by an adjustable flame temperature factor. This thermal mechanism will guide the future work on selecting new combinations of binary agents.
and sharing with colleagues.
The objective of this work was to determine the accuracy and limitations of a new version of Fire... more The objective of this work was to determine the accuracy and limitations of a new version of Fire Dynamics Simulator (FDS), developed by McGrattan et al., on axi-symmetric fire plumes. The current version uses LES for turbulence, a mixture-fraction-based infinitely fast chemistry model for combustion, and a constant radiative loss fraction. These sub-models have been tested for unconfined fires of different sizes, based on a dimensionless heat release rate Q Ã D in the range of 0.1 to 10.0, which covers most natural fire scenarios. No adjustment of constants or algorithms in the model FDS2.0 have been made. An examination of plume theory is made first to find the benchmark correlations. This shows a generalization for a collection of correlations based on theory, and which might be ''the best''. Using the characteristic length as the scaling factor, it is found that the optimum resolution of a pool fire simulation is around 0.05. With this resolution, the flame height prediction is found to fit well with flame height correlations. Some other parameters such as temperature and mixture fraction are found to be close to the empirical estimations at flame tips. The Froude number, which describes the relative strength of momentum and buoyancy, falls within the measurement range of many researchers. The simulation also reveals that the temperature near the burner is over-predicted, while the centerline temperature and velocity in the noncombusting region is predicted well. r