Introduction To determine the temperature differences encountered in the flow of heat within electronic systems, it is necessary to recognize the relevant heat transfer mechanisms and their governing relations. In a typical system, heat removal from the active regions of the microcircuit(s) or chip(s) may require the use of several mechanisms, some operating in

AIR-HEATING PROCESSES Air can be heated by burning fuel or by recovering waste heat from another process. In either case, the heat can be transferred to air directly or indirectly. Indirect air heaters are heat exchangers wherein the products of combustion never contact or mix with the air to be heated. In waste heat recovery, the heat exchanger is termed a recuperator. Direct air heaters or direct-fired air heaters heat the air by intentionally mixing the products or combustion of waste gas with the air to be heated. ...

Heat exchangers permit exchange of energy from one fluid to another, usually without permitting physical contact between the fluids. The following configurations are commonly used in the power and process industries.

ENERGY MANAGEMENT AND THE ENERGY AUDIT Energy auditing is the practice of surveying a facility to identify opportunities for increasing the efficiency of energy use. A facility may be a residence, a commercial building, an industrial plant, or other installation where energy is consumed for any purpose. Energy management is the practice of organizing

Geothermal energy is the internal heat of the Earth. For centuries, geothermal energy was apparent only through anomalies in the Earth's crust that allow the heat from the Earth's molten core to venture close to the Earth's surface. Volcanoes, geysers, fumaroles, and hot springs are the most visible surface manifestations of these anomalies. Geothermal energy has been used for centuries where it is available for

Solar energy is defined as that radiant energy transmitted by the sun and intercepted by earth. It is transmitted through space to earth by electromagnetic radiation with wavelengths ranging between 0.20 and 15 microns.

Nature Coal is a dark brown to black sedimentary rock derived primarily from the unoxidized remains of carbon-bearing plant tissues. It is a complex, combustible mixture of organic, chemical, and mineral materials found in strata, or "seams," in the earth, consisting of a wide variety of physical and chemical properties.

The major source of liquid fuels is crude petroleum; other sources are shale and tar sands. Synthetic hydrocarbon fuels—gasoline and methanol—can be made from coal and natural gas. Ethanol, some of which is used as an automotive fuel, is derived from vegetable matter. Crude petroleum and refined products are a mix of a wide variety of hydrocarbons—aliphatics (straight- or branched-chained paraffins and olefins), aromatics (closed rings, six carbons per ring with alternate double bonds joining the ring carbons, with or without aliphatic side chains), and naphthenic or cycloparaffins (closed...

Gaseous fuels are generally easier to handle and burn than are liquid or solid fuels. Gaseous fossil fuels include natural gas (primarily methane and ethane) and liquefied petroleum gases (LPG; primarily propane and butane). Gaseous man-made or artificial fuels are mostly derived from liquid or solid fossil fuels. Liquid fossil fuels have evolved from animal remains through

A new and increasing responsibility of furnace designers and operators is to provide controls for toxic, combustible, or particulate materials in furnace flue gases, to meet federal or local standards for air quality.

This chapter has been prepared for the use of engineers with access to an electronic calculator and to standard engineering reference books, but not necessarily to a computer terminal. The intent is to provide information needed for the solution of furnace engineering problems in areas of design, performance analysis, construction and operating cost estimates, and improvement programs.

Air-Fuel Ratios Combustion is rapid oxidation, usually for the purpose of changing chemical energy into thermal energy—heat. This energy usually comes from oxidation of carbon, hydrogen, sulfur, or compounds containing C, H, and/or S. The oxidant is usually O2—molecular oxygen from the air.

In other types of heat exchangers, where the values of the overall heat transfer coefficient, [/, may vary over the area of the surface, the LMTD may not be representative of the actual average temperature difference.

The exchange of energy or heat resulting from the kinetic energy transferred through the direct impact of molecules is referred to as conduction and takes place from a region of high energy (or temperature) to a region of lower energy (or temperature).

In this chapter, we review two important methods that account for much of the newer work in engineering thermodynamics and thermal design and optimization. The method of exergy analysis rests on thermodynamics alone.

Thermodynamics has historically grown out of man's determination—as Sadi Carnot put it—to capture "the motive power offire."Relative to mechanical engineering, thermodynamics describes the relationship between mechanical work and other forms of energy. There are two facets of contemporary thermodynamics that must be stressed in a review such as this. The first is the equivalence of work and heat as two

A solid generally has a definite shape; a fluid has a shape determined by its container. Fluids include liquids, gases, and vapors, or mixtures of these. A fluid continuously deforms when shear stresses are present; it cannot sustain shear stresses at rest.

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Physical properties of metals, ceramics, and polymers, such as ductility, thermal expansion, heat capacity, elastic modulus, electrical conductivity, and dielectric and magnetic properties, are a direct result of the structure and bonding of the atoms and ions in the material. An understanding of the origin of the differences in these properties is of great engineering importance.

These handling methods are implemented individually, or in combination, by commercially available material-handling equipment types. 38.5 MATERIAL-HANDLING EQUIPMENT CONSIDERATIONS AND EXAMPLES 3 . . Developing the Plan 851 Once the material-handling problem has been identified and the relevant data have been collected and analyzed, the next step in the design process is to develop a plan for solving the problem. This usually involves the design and/or selection of appropriate types, sizes, and capacities of materialhandling equipment. In order to properly select material handling equipment, it must be realized that in most cases, the solution to the problem does not consist...