Heat exchangers: types .................................................................................................................................. 1 Plate heat exchangers ................................................................................................................................ 4 Shell-and-tube heat exchangers ............................................................

Heat exchangers: types .................................................................................................................................. 1 Plate heat exchangers ................................................................................................................................ 4 Shell-and-tube heat exchangers ............................................................

Nucleate boiling heat transfer coefficients may be strongly reduced by scale formation, even for conditions where the bulk foulant concentration is well below the saturation concentration. Due to the mechanism of micro-layer evaporation, the local concentration at the heat transfer surface can be considerably increased, causing the formation of scale and changes in bubble frequency and bubble d...

In this study, thermal performance across straight convecting- radiating fin with temperature dependent thermal conductivity is considered. The variation of parameters (VPM) is adopted to analyze the nonlinear higher order differential equations arising due to thermal conductivity and heat transfer coefficient on temperature distribution. Pertinent parameters such as thermo geometric and radiat...

This paper presents some of the results of the simulation in the radiation section of an industrial boiler using an advanced mathematical model. Calculations are described for the flow, heat transfer, and chemical reaction processes occurring within a gas-fired cylindrical furnace. The calculation procedure is a two dimensional one in which the main hydrodynamic variables are the velocity and s...

For many countries, increasing energy efficiency and reducing greenhouse gas emissions are key countermeasures to cope with the energy crisis and climate change. Of the various heating equipment such as heat pumps, gas-fired boilers, oil-fired boilers, or electric boilers, heat pumps are widely adopted for space heating, water heating, and process heating by households, business, and industry d...

The operating principle of condensing boilers is based on exploiting heat from flue gases to pre-heat cold water at the inlet of the boiler: by condensing into liquid form, flue gases recover their latent heat of vaporization, leading to 10e12% increased efficiency with respect to traditional boilers. However, monitoring the energy efficiency of condensing boilers is complex due to their nonlin...

The management of coal ash in utility boilers continues to be one of the most important fuel property considerations in the design and operation of commercial boilers. The behavior of mineral matter in coal can significantly influence furnace sizing, heat transfer surface placement, and convection pass tube spacing. Ironically, many of the more reactive, low rank U. S. coals must have larger fu...

Renewable energy sources are essential paths towards sustainable development and CO2 emission reduction. For example, the European Union has set the target of achieving 22% of electricity generation from renewable sources by 2010. However, the extensive use of this energy source is being avoided by some technical problems as fouling and slagging in the surfaces of boiler heat exchangers. Althou...