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16 Cards in this Set
- Front
- Back
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Define a heat exchanger |
A heat exchanger is a device used to exchange thermal energy between two fluids or mixture's, from the hotter one to the cooler one. |
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What is a common working fluid in a heat exchanger |
Steam |
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Why is steam used as a heat exchanger. |
- good at carrying heat by convection. - high heat capacity, so it won't change its temperature much in the exchanger. - relatively cheaper.although steam is expensive to produce it can be obtained from water, which is cheaper than other working fluids. |
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Applications of heat exchanger |
Chemical plants Power plants Process plants Air conditioning Space heating |
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What are the 3 flow arrangements of the heat exchanger |
Parallel flow Counter flow Cross flow |
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Explain parallel flow arrangement |
Enter at the same side. Travel parallel to each other in same direction Exit at the same end of exchanger |
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Explain counter flow pattern |
Enter at diff ends Flow parallel to eachother but in opposite directions Leave at dear diff ends |
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Explain Cross flow arrangement |
Enter at same end of exchanger. Travel perpendicular to each other Exit at the same end |
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List 4 types of heat exchangers |
Plate HE shell and tube HE Double pipe HE Shell HE Shell HE HE |
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What heat exchanger type is focuses on in this module |
Plate HE |
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Describe the structure of a plate heat exchanger |
Composed of multiple thin slightly spaced plates. plates have large surface area and fluid flow passages for heat transfer. They are separated by rubber sealing gaskets, cemented to the corners of each plate. Plates are pressed to form troughs at right angles to the direction of fluid flow. They are arranged so that they can interlink with the other trays, forming gap of 1.3-1.5mm |
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We want to increase the temperature difference in the plate heat exchanger. What to do? |
Increase the number of plates. |
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Applications of heat exchanger acronym |
WWHTCF |
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Applications of heat exchanger |
Water heater Waste heat recovery Heat pump isolation Thermal (ice) storage system Cooling tower isolation Free cooling |
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Describe the maintenance required by the water heater |
Must be periodically disassembled and cleaned. In large scale water cooling systems, water treatment must occur which includes, water purification adding chemicals, testing. This is one to prevent the fouling of heat exchanger equipment. |
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Costs |
? |
