The combined heat and mass transit processes of water droplets in biofuel technologies

Abstract

The number of thermal technologies is based on water droplets heat and mass transfer processes. In this paper droplets heat transfer and phase transformations were modelled in the context of water spraying in humid flue gases application for biofuel combustion technologies. Droplets warming is defined when its surface instantaneous temperature is calculated according to an iterative numerical scheme, which is based on heat fluxes balance that flows in and from the droplet surface. The transfer processes interaction is taken into account. The influence of spraying water temperature, biofuel flue gases temperature and its humidity as well as droplets heating process impact on spraying water droplets transit phase transformation regimes were highlighted. Technological cases of water spraying in a biofuel furnace and heat recovery from removed flue gases were highlighted. In condensing economizers at recovered flue gases sprayed droplets heat transfer conditions are defined by their slipping factor in flue gases, while in the case of biofuel combustion in the furnace, droplets slipping and its surrounding radiation factors are equivalent.

Hydrogen Oxyfuel Combustion for Energy-Intensive Industries

“…As the name suggests, latent heat of the flue gas stream is also utilized in a condensing economizer. Usually installed by the district heat producers to increase the total efficiency [51,52], condensing economizers are also discussed for the flue gas heat recovery. However, the heat recovered would be useful only for low-temperature heat demand.…”

A Study of Air Velocity in a Cooling Tower that Affects the Diameter of the Droplet

“…Then, the mathematical model that calculates interactions between water and airin the form of changes in droplet radius R(z) (m), droplet fall velocity v(z) (m/s), droplet temperature Tw(z) (K), air temperature Ta(z) (K), and droplet density ρ(z) (kg/m 3 ) along the z-axis is presented by Equation (11), Equation (12), Equation (13), Equation ( 14), and Equation (15), respectively [15,16].…”

“…Investigation about the phenomena of the water and air that work in it is an enticing thing to do, such as the droplet evaporation [1,6]. Observations were made to the level of droplets to get a high level of accuracy [6][7][8][9][10][11][12]. It described fluid interactions in the form of mathematical modelling obtained from governing equations, for example, the droplet surface temperature, the average water temperature, change in velocity of the falling droplet, and so on [13][14][15][16].…”