ANALYSIS OF THE REGION OF VALIDITY OF EQUATIONS FOR CALCULATING HEAT EXCHANGERS OF THE TUBE-IN-TUBE TYPE

Based on the traditional model with direct fl ow and counterfl ow of heat transfer agents in a stationary regime, the operation of a heat exchanger of the tube-in-tube type is analyzed. Account is taken of the natural limitations for the model that are connected with the possibility of practical realization of the similarity numbers involved in the equations of the model, as well as with the conditions (assumptions) invoked in the derivation of the model. A comparison of the effi ciency of heat transfer in the noted regimes of heat transfer agent motions is made. For the purposes of this comparison, it is proposed to use an averaged value of the function that represents the ratio of effi ciencies with heat transfer agent direct fl ow and counterfl ow over the region of possible values of similarity numbers. The necessary calculations and illustrations are presented.
   
Author:  A. I. Moshinskii
Keywords:  heat transfer, heat exchanger, heat transfer agent, direct flow, counterflow
Page:  1119