Thermal design of a heat exchanger for heating or cooling blood.

Experimental data, and their correlation with predictions from theory, are presented for the thermal design of a countercurrent heat exchanger for heating or cooling blood. The thermal design considers the influence on the Nusselt number of blood and the heat exchanger effectiveness of variables such as the blood flow rate, tube diameter and length, and the thermal properties of blood. The data presented are compared with data from the literature and with predictions from theory. Insofar as the design of a blood heat exchanger is concerned, flowing blood can be considered a single-phase fluid. Results of the thermal design analysis are applicable to attempts to produce and control blood hyperthermia for applications such as the perfusion of tumours of the extremities, and to efforts to induce hypothermia during open-heart surgery.