HEAT TRANSFER ENHANCEMENT IN DOUBLE PIPE HEAT EXCHANGER USING WASHERS AS AN INSERTS

Researchers are used different heat transfer enhancement techniques in double pipe heat exchanger by inserting various types of twisted tapes in last few years. These techniques are more applicable in various industrial areas such as cryogenics, process industries, HVAC systems etc. There is need to improve the outside heat transfer coefficient, effectiveness and thermal performance of heat exchanger, thereby reducing the cost and size of heat exchanger. In present paper washers with octagonal slot used as a insert to improve heat transfer and to reduce the weight and size of heat exchanger. Heat transfer performance of heat exchanger with washers is higher than normal heat exchanger but pressure drop, pumping power is also higher. When only heat transfer and annulus heat transfer coefficient performance is considered no consideration of pressure drop, pumping power heat exchanger with washers is superior than normal heat exchanger.