張林偉小組英語(yǔ)

1、Chemical Engineering Chemical Engineering and and TechnologyTechnology張林偉張林偉張佳佳張佳佳張安媛張安媛易佳佳易佳佳13化工Heat exchanger13化工A heat exchanger is a device built for efficient heat transfer from one medium to another. The media may be separated by a solid wall, so that they never mix, or they may be in direct

2、contact.They are widely used in space heating, refrigeration, air conditioning, power plants, chemical plants, petrochemical plants, petroleum refineries, natural gas processing, and sewage treatment. One common example of a heat exchanger is the radiator in a car, in which the heat source, being a

3、hot engine-cooling fluid, water, transfers heat to air flowing through the radiator (i.e. the heat transfer medium).1、Introduction09化工2、Types of heat exchangersShell and tube heat exchangers consist of (由由組成組成)a series of tubes. One set of these tubes contains the fluid that must be either heated or

4、 cooled. The second fluid runs over the tubes that are being heated or cooled so that it can either provide the heat or absorb the heat required. A set of tubes is called the tube bundle and can be made up of several types of tubes: plain, longitudinally finned, etc. Shell and tube heat exchangers a

5、re typically used for high-pressure applications (with pressures greater than 30 bar and temperatures greater than 260C). This is because the shell and tube heat exchangers are robust due to their shape. that引導(dǎo)的定語(yǔ)從句修飾引導(dǎo)的定語(yǔ)從句修飾 the fluid。 that引導(dǎo)的是定語(yǔ)從句，說(shuō)明其前的引導(dǎo)的是定語(yǔ)從句，說(shuō)明其前的the tubes的狀況，的狀況，so that引導(dǎo)了一個(gè)目

6、的引導(dǎo)了一個(gè)目的狀語(yǔ)從句。狀語(yǔ)從句。13化工3、inside constitute of heat exchangers13化工13化工Another type of heat exchanger is the plate heat exchanger. One is composed of multiple, thin, slightly-separated plates that have very large surface areas and fluid flow passages for heat transfer. This stacked-plate arrangement ca

7、n be more effective, in a given space, than the shell and tube heat exchanger. Advances in gasket and brazing technology have made the plate-type heat exchanger increasingly practical. In HAVC applications, large heat exchangers of this type are called plate-and-frame; when used in open loops, these heat exchangers are normally of the gasketed type to allow periodic disassembly, cleaning, and i