Heat transfer

Experimental and numerical study of the effect of water injection into the reaction zone of a flameless combustion furnace

The effect of water injection on the stability and emissions of a flameless combustion regime was evaluated. Flameless combustion operation was studied without self-regeneration, with self- regeneration, and with combustion air oxygen enrichment. For each case, increasing water flows were injected until the combustion regime was unstable. The evaluation criteria were temperature uniformity and pollutant emissions of species such as carbon monoxide and nitrogen oxide.

A numerical analysis of the effect of atmospheric pressure on the performance of a heating system with a self-recuperative burner

This work evaluated the performance of a combustion chamber operating with a self-recuperative burner at various atmospheric pressures by means of Computational Fluid Dynamics (CFD) simulation. The aim was to determine the effect of atmospheric pressure on the main variables of the combustion system through mathematical correlations and numerical simulations.

A numerical analysis of the effect of heat recovery burners on the heat transfer and billet heating characteristics in a walking-beam type reheating furnace

The present study presents a numerical simulation of the effects of using self-recuperative burners on the performance of a walking-beam reheating furnace. The study was done using CFD (Computational Fluid Dynamics) simulations where a low computational cost method was implemented to simulate the billet heating as a steady state system. The preheating temperature of the air was defined as a function of the air mass flow and the flue gas temperature in each burner, using a UDF (User-Defined Function).

Numerical analysis of internal recirculation into a radiant tube without internal ignition

This paper presents a numerical analysis using the CFD Fluent (6.3.26 version) program to identify the effects that can be generated when using radiant tubes with internal recirculation of combustion products, but with a pre-combustion chamber. The numerical results are validated with an experimental assembly based on the outlet deviation of gases temperature. These deviations were less than 5 % and are attributed principality to isolation deficiency in the re-radiant surface.

Effect of the trapped mass and its composition on the heat transfer in the compression cycle of a reciprocating engine

The use of the polytropic coefficient calculation during the compression process in the thermodynamic cycle of a reciprocating internal combustion engine is an interesting tool to minimize errors in the synchronization of pressure and volume signals, and to determine heat flux transferred to the cylinder walls. The accuracy of this calculation depends on the instantaneous values for pressure, volume, trapped mass and its composition, as well as on their variations.