Combustion and Heat Transfer Analysis of Gas fired heat exchanger unit using CFD

Abstract

Understanding of combustion process and heat transfer rate and its performance is critical to complying with (progressively more) rigorous emissions requirements and to improving industrial productivity. Even small improvements in heat transfer rate will increase in energy efficiency and performance of the subsystems and which can have significant impacts in a continuous operation. While tremendous advances have been made in understanding the fundamental science of combustion process and the conjugate heat transfer, the remaining challenges are extremely complex. Today, trial and error is the only satisfactory method heat exchanger tubes design and problem-solving approach. To make improvements, it is critical to understand and accurately predict how heat is released and heat transferred across tube thickness and heat pickup by external air which is result in temperature rise by external air. Computational fluid dynamics (CFD) offers a numerical modeling methodology that helps in this understanding. Combustible character of Natural gas (Methane) is one major area which uses Natural gas as a fuel. Hot combustible gas passes through inside the tube and cold air passes around the tubes understanding heat transfer across tube thickness and improve the design of tubes to increase the effectiveness of heat transfer is very important in design optimization of gas heaters system for HVAC industrial application. Burner and tubes are being the component where the combustion process takes place, produces emissions & heat transfer taken place across tubes thickness, thereby, making the fuels less environment friendly. But, with the use of natural gas as fuel for burner, the emissions are reduced to a considerable extent.