Molecular Gas Band Radiation

TLDR: In this article, a nongray radiation heat transfer analysis for problem situations involving molecular gases with infrared vibration rotation bands when the gaseous mixture is in a state corresponding to thermodynamic equilibrium at the local thermodynamic state variables: pressure, temperature, and composition.

Abstract: Publisher Summary Radiation heat transfer involving molecular gases is the desirable effect in fossil-fuel or waste-fired steam generators for power production or process steam supply and in industrial heat-treating, melting, or enameling furnaces Heat radiation from gases may be utilized as a means of heat transfer and also of information transfer Information on the location, extent, composition, and temperature of a volume of molecular gases can be inferred from thermal radiation measurements The information obtained can be used by process control, fire and air pollution warning and monitoring systems, and by weapon and brush-fire-suppressant targeting or guidance systems This chapter examines how to make a nongray radiation heat transfer analysis for problem situations involving molecular gases with infrared vibration rotation bands when the gaseous mixture is in a state corresponding to thermodynamic equilibrium at the local thermodynamic state variables: pressure, temperature, and composition The special circumstances under which total emissivity and total absorptivity appear as useful quantities are derived, and approximations extending their utility are discussed The chapter examines how the more general and difficult problem of a nonisothermal gas is treated Some particular solutions for the parallel-plate duct are described, both to illustrate nonisothermal gas analysis and to obtain wall-layer transmission factors to extend the utility of engineering models employing an isothermal gas volume concept The chapter provides a brief description of the experimental knowledge of molecular gas behavior and a review of the fundamental ideas of radiation transfer The spectral band nature of gas radiation is briefly described and correlations for working calculations of gas radiation properties are presented