doiSerbia

Geothermal heat exchanger with coaxial flow of fluids

Pejić Dragan M. (Tehnološki fakultet, Leskovac)
Stojiljković Dragan T. (Tehnološki fakultet, Leskovac)
Stojiljković Staniša T. (Tehnološki fakultet, Leskovac)
Đurović-Petrović Maja (IHTM, Beograd)
Mitić Nebojša (Tehnološki fakultet, Leskovac)

The paper deals with a heat exchanger with coaxial flow. Two coaxial pipes of the secondary part were placed directly into a geothermal boring in such a way that geothermal water flows around the outer pipe. Starting from the energy balance of the exchanger formed in this way and the assumption of a study-state operating regime, a mathematical model was formulated. On the basis of the model, the secondary circle output temperature was determined as a function of the exchanger geometry, the coefficient of heat passing through the heat exchange areas, the average mass isobaric specific heats of fluid and mass flows. The input temperature of the exchanger secondary circle and the temperature of the geothermal water at the exit of the boring were taken as known values. Also, an analysis of changes in certain factors influencing the secondary water temperature was carried out. The parameters (flow temperature) of the deep boring B-4 in Sijarinska Spa, Serbia were used. The theoretical results obtained indicate the great potential of this boring and the possible application of such an exchanger.

Keywords: geothermal energy, heat exchanger, coaxial flow