Task 4 Read the text. Write an abstract to the following text.
Task 4
Read the text. Write an abstract to the following text.
The length of the abstract is 100–120 words.
Max score -5 / Min score-2.
Send your answer as an attached file.
Try to use the recommendations in the attached file.
HEAT EXHANGER
A device used to transfer heat from a fluid flowing on one side of a barrier to another fluid flowing on the other side of the barrier. When used to accomplish simultaneous heat transfer and mass transfer, heat exchangers become special equipment types, often known by other names. When fired directly by a combustion process, they become furnaces, boilers, heaters, tube-still heaters, and engines. If there is a change in phase in one of the flowing fluids – condensation of steam to water, for example – the equipment may be called a chiller, evaporator, sublimator, distillation-column reboiler, condenser, or cooler-condenser.
Heat exchangers may be so designed that chemical reactions or energy generation processes can be carried out within them, e.g. a nuclear reactor, catalytic reactor, or polymerizer. Heat exchangers are normally used for the transfer and useful elimination or recovery of heat without an accompanying phase change. The fluids on either side of the barrier are usually liquids, but they may also be gases such as steam, air, or hydrocarbon vapors; they may be liquid metals such as sodium or mercury.
Most often the barrier between the fluids is a metal wall such as that of a tube or pipe. It can be fabricated from flat metal plate, graphite, plastic, or other corrosion-resistant materials of construction. Heat exchangers find wide application in the chemical process industries, including petroleum refining; in the food industry for pasteurization of milk and canning of processed foods; in the generation of steam for production of power and electricity; in nuclear reaction systems; in aircraft and space vehicles; and in the field of cryogenics for the low temperature separation of gases. Heat exchangers are the workhorses of the entire field of heating, ventilating, air-conditioning, and refrigeration.
