Heat Transfer

(redirected from Boiling heat transfer)

Heat transfer

Heat, a form of kinetic energy, is transferred in three ways: conduction, convection, and radiation. Heat transfer (also called thermal transfer) can occur only if a temperature difference exists, and then only in the direction of decreasing temperature. Beyond this, the mechanisms and laws governing each of these ways are quite different. See Conduction (heat), Convection (heat), Heat radiation

By utilizing a knowledge of the principles governing the three methods of heat transfer and by a proper selection and fabrication of materials, the designer attempts to obtain the required heat flow. This may involve the flow of large amounts of heat to some point in a process or the reduction in flow in others. All three methods operate in processes that are commonplace.

In industry, for example, it is generally desired to extract heat from one fluid stream and add it to another. Devices used for this purpose have passages for each of the two streams separated by a heat-exchange surface in the form of plates or tubes and are known as heat exchangers. The automobile radiator, the hot-water heater, the steam or hot-water radiator in a house, the steam boiler, the condenser and evaporator on the household refrigerator or air conditioner, and even the ordinary cooking utensils in everyday use are all heat exchangers. See Heat

Heat transfer

A generic term for thermal conduction, convection, and radiation.

Heat Transfer

 

the spontaneous irreversible movement of heat in space owing to a nonuniform temperature field. In the general case, heat transfer may also result from the nonuniformity of the fields of other physical quantities; an example is a difference in concentrations. Heat is transferred in three ways: conduction, convection, and radiation. In practice, heat transfer usually occurs through all three mechanisms at the same time.

Heat transfer determines or accompanies many processes in daily life, in technology, and in nature—for example, meteorological processes at the earth’s surface and the evolution of stars and planets. In many cases, such as in the study of dehydration, evaporative cooling, and diffusion, heat transfer is considered together with mass transfer. A special case of heat transfer is the flow of heat from one heat-transfer fluid to another through a solid wall separating the fluids or through an interface between the fluids.

heat transfer

[′hēt ¦tranz·fər]
(thermodynamics)
The movement of heat from one body to another (gas, liquid, solid, or combinations thereof) by means of radiation, convection, or conduction.

Heat transfer

Heat, a form of kinetic energy, is transferred in three ways: conduction, convection, and radiation. Heat transfer (also called thermal transfer) can occur only if a temperature difference exists, and then only in the direction of decreasing temperature. Beyond this, the mechanisms and laws governing each of these ways are quite different. See Conduction (heat), Convection (heat)

By utilizing a knowledge of the principles governing the three methods of heat transfer and by a proper selection and fabrication of materials, the designer attempts to obtain the required heat flow. This may involve the flow of large amounts of heat to some point in a process or the reduction in flow in others. All three methods operate in processes that are commonplace.

In industry, for example, it is generally desired to extract heat from one fluid stream and add it to another. Devices used for this purpose have passages for each of the two streams separated by a heat-exchange surface in the form of plates or tubes and are known as heat exchangers. The automobile radiator, the hot-water heater, the steam or hot-water radiator in a house, the steam boiler, the condenser and evaporator on the household refrigerator or air conditioner, and even the ordinary cooking utensils in everyday use are all heat exchangers. See Heat exchanger

heat transfer

The flow of heat from one body at higher temperature to another body at a lower temperature, until the two temperatures are equal.
References in periodicals archive ?
Table 2 shows the main equations for the boiling heat transfer correlations.
Review of boiling heat transfer enhancement on micro/nanostructured surfaces, Experimental Thermal and Fluid Science 66: 173-196.
One important remark is that near the CHF both curves coincide because in those conditions boiling level is so high that boiling heat transfer outweighs forced-convection which can be expressed by equation (2) [1], that is normally accepted and states that the overall heat transfer at the wall can be obtained as the sum of forced convection and nucleate boiling.
They cover boiling heat transfer and critical heat flux phenomena of nanofluids; modeling for heat transfer of nanofluids using a fractal approach; thermal conductivity enhancement in nanofluids measured with a hot-wire calorimeter; two-phase laminar mixed convection Al2O3-water nanofluid in an elliptic duct; nano-oncology: molecular imaging, omics, and nanoscale flow-mediated medicine tumors strategies; and nanoscale flow applications in medicine.
ABSTRACT: A numerical analytical system is suggested to entice bubble nucleation for the concept of flow boiling heat transfer in microchannels heat sink.
Enhancement of boiling heat transfer due to the application of metallic powder coating of 30-75% porosity was analysed in (Afgan et al.
A team of engineering researchers in the US has succeeded in carrying out the first systematic investigation of the factors that control boiling heat transfer from a surface to a liquid.
The majority of the research in nanofluids for heat transfer applications has been around boiling heat transfer.
Nucleate pool boiling heat transfer characteristics of refrigerant/oil mixtures on metal foam covers were experimentally investigated at a wide range of oil concentrations.
Chen, A correlation for boiling heat transfer to boiling fluids in convective flow.
Nanotube and nanowire arrays are another effective way to enhance pool boiling heat transfer.
Electric Field Effects on Pool Boiling Heat Transfer experiments from the University of Maryland and University of Pisa, Italy; Jungho Kim and Paolo DiMarco, co-PIs.