12-12-2012, 04:03 PM
Losses Due to Ineffectiveness of Regenerator in a Pulse Tube Refrigerator
Abstract
Regenerator is a heat exchanger in which heat and cold fluids pass alternately through a space containing solid matrix particles. A regenerator generally operates periodically used in cryogenic. The regenerator has several distinctadvantages it can be made relativelywall,its efficiency is very high, matrix materials are readily available, its construction is simple.
Regenerator loss in the regenerator is one of main factors to improve the cooling characteristics. Refrigeration capacity of a pulsetube refrigerator decreases due to the additional losses associated with the regenerator are the thermal loss, pressure loss, ineffectiveness, regenerator pneumatic loss and conduction loss. Since a number of screens and lead spheres are tightly packed into the regenerator to increase the heat transfer area, which cause the pressure drop for flow through the regenerator results in a cooling power loss. But if we reduce the screens and lead spheres it will affect heat transfer area which will decrease the heat transfer rate in the regenerator and increases the temperature at the cold end of the regenerator, and results an additional load on the cold heat exchanger. These losses are quantified by the regenerator ineffectiveness. In the present research work different type of regenerator losses are calculated using the commands of Matlab. Result shows that if these losses we can decrease there increase in refrigeration capacity of a Pulse tube refrigerator.