METHOD OF CONTROLLING TUBE TEMPERATURES TO PREVENT FREEZING OF FLUIDS IN CROSS COUNTERFLOW SHELL AND TUBE HEAT EXCHANGER

摘要

Methods and apparatus for controlling tube temperatures may prevent freezing of fluids in cross counterflow shell and tube heat exchangers. Cold gas may flow inside the tubes of the heat changer and warm liquid may flow outside the tubes. The tube diameter and tube spacing may be varied through the tube passes through the heat exchanger in order to provide a hot side conductance to cold side conductance ratio which results in the tube temperature being safely above the liquid freezing point. The heat exchanger may be used in, for example, the aerospace industry as a fuel oil cooler or as a preconditioner for reactants in a spacecraft propulsion system.