The Effect of Water Spray upon Incineration Flue Gas Clean-up

The existence of liquid water was found very important in incineration flue gas clean-up systems for enhancing the absorption of acid components contained. In a newly developed incineration flue gas clean-up tower, which works in a semi-dry mode, the water is injected in the form of spray to maximum its contact surface with the gas. The criteria for the design of the water nozzles would be nigh water concentration but no liquid impinging on the solid wall and complete evaporation inside the tower. In order to optimize the atomizer design, the effects of the spray type (hollow or solid cone), their initial droplet she distribution and water flow rate on the performance of the acid gas absorption were investigated. The liquid behaviour was studied with a fluid dynamic simulation code, and the overall performance was checked experimentally. This paper presents the use of a commercial CFD code, FLUENT, and some modifications made during such investigation. The modification includes the viscosity of the flue gas defined as a function of the temperature, and the initial mass fraction of different droplet size group described with an exponential distribution formula of Rosin-Rammler. The investigation results (the optimal spray parameters) were used to guide the water nozzle design. The general performance of the flue gas clean-up system measured during the plant operation complied with the design criteria.

Fuel Property Effects on Liquid and Vapor Penetrations of Evaporating Sprays

The purpose of this study is to investigate the effect of fuel properties on liquid and vapor penetrations in evaporating spray systems. A recently developed model, which can simultaneously account for the finite thermal conductivity, finite mass diffusivity and turbulence effects within atomizing multi-component liquid fuel sprays, is utilized for the numerical predictions. Two different multi-component fuels with different boiling temperatures,densities and other thermal properties are implemented in the KIVA-3V computational fluid dynamics(CFD)code to study the evaporation behaviors. A six-component surrogate fuel is used to emulate the relevant volatility property of the real diesel fuel, and a second bi-component fuel is chosen to represent a low boiling-temperature fuel. The numerical results are compared with the experimental data, and the representative results are obtained.For a lower density and lower boiling temperature fuel, the liquid penetration length is shorter. However, the vapor penetration lengths are not affected by the fuel type in terms of fuel volatility. Available experimental data are used for validation and appraisal of the multi-component evaporation model.

Large matrix polymer solar cells fabricated by low cost air-brush spray deposition

In this paper,a 64 mm×64 mm matrix polymer solar cell(PSC) was fabricated by air-brush spray deposition.Although the open-circuit voltage(Voc) and the fill factor(FF) both need to be improved,the efficiency of matrix PSCs still reaches about 1.82%,and especially the current density achieves nearly 20 m A/cm2.The results verify that air-brush spray deposition is a suitable method to prepare large area PSC devices,and the process we use in this paper can be easily transplanted to roll-to-roll production.