Heat Transfer

(redirected from Heat absorption)

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 ?
The IPCC explains that CO2 follows a logarithmic dependence, which means that it takes ever-doubling amounts of CO2 to keep adding the same amount of heat absorption in the atmosphere.
Our oceans do the heavy lifting with respect to carbon dioxide and heat absorption and their capacity to continue to do these things is one of many areas we are focused on through our climate research.
Silicon Park will leverage green building materials and control mechanisms as well as solar panels and double-glazed windows to reduce heat absorption.
The 223-unit community offers a wide range of innovative, energy-efficient design elements including heat absorption minimization from the sun and energy-efficient lighting systems, water conservation with low-flow plumbing fixtures providing 30 percent more water efficiency, highly reflective "cool-roof" surfacing and sustainable operation measures.
This solar reflective coating delivers an eco-friendly way to resist heat absorption from the sun without sacrificing durability, performance or beauty.
The Persian Gulf region is especially vulnerable, the researchers say, because of a combination of low elevations, clear sky, water body that increases heat absorption, and the shallowness of the Persian Gulf itself, which produces high water temperatures that lead to strong evaporation and very high humidity.
There would be escalators to enable people move up to the station without taking a single step and roof of the stations would be made of insulated sheets to avoid heat absorption.
And although recycled rubber roofs are durable, they off-gas, especially in sunlight, they contaminate rainwater, and their black color increases heat absorption, which heats up your house.
Also, to investigate the effect of PCM concentration (in CNT coating layer) on heat absorption, we repeated the test for an extra sample of solar tube coated with CNT and 14 gr [0.
With high-temperature polymers, oil cooling is preferred in the solids feeding area, as the high heat absorption of water--particularly as it flashes to steam--could extract enough heat from the screw to disrupt melting farther down the screw.
43] investigated the problem of an unsteady MHD free convective flow past an impulsively started vertical plate with ramped temperature immersed in a porous medium with rotation and heat absorption taken into account the Hall Effect.
This is heat absorption, do not confuse it with heat conductivity.