A semi-analytical method for determining unsteady temperature field in a parallel-flow three-fluid heat exchanger

Transient temperature field in a parallel-flow three-fluid heat exchanger with the thermal capacitance of the walls and the longitudinal walls conduction

“…The correctness of the mathematical model adopted and the method of solution used is verified by comparing the results obtained from the numerical method with those from a semi-analytical solution for the case of a co-current three-fluid heat exchanger with two thermal couplings [10]. The present model with three thermal 13 couplings, accounting for the thermal capacity of the walls and heat conduction along the walls, is reduced to the model analysed in the work [10] Verifying calculations are carried out assuming that the system, initially at steady-state, undergoes an exponential rise of the inlet temperature of the fluid flowing through channel no.…”

“…The present model with three thermal 13 couplings, accounting for the thermal capacity of the walls and heat conduction along the walls, is reduced to the model analysed in the work [10] Verifying calculations are carried out assuming that the system, initially at steady-state, undergoes an exponential rise of the inlet temperature of the fluid flowing through channel no. 1.…”

“…(1) - (13) is solved numerically by means of the MacCormack implicit predictor-corrector method [22 -24]. This two-step finite difference method of second order accuracy is very effective 9 for solving classical transient heat transfer problems in heat exchangers, both for a step change in flow rate and for a step change in inlet temperature [10,11,13].…”

“…However, in most cases, the solutions presented ACCEPTED MANUSCRIPT 4 refer to the determination of steady-state temperature fields [1 -7]. According to the best knowledge of the authors, the available literature gives little information regarding mathematical modelling of transient behaviour of such exchangers [8][9][10][11][12][13][14][15][16][17][18][19][20][21]. Sekulic and…”

New integral-mean temperature difference model for thermal design and simulation of parallel three-fluid heat exchanger

“…Bielski and Malinowski [21] presented a semi-analytical method and analytical method [22] to analyze the dynamic behaviour of parallel three-fluid heat exchanger with two thermal communications. Recently, they further set up the numerical model [23] that takes into account the thermal capacitance of the walls, the longitudinal heat conduction through the walls, and the conductive resistance across the walls to study the transient temperature response of the parallel three-fluid heat exchanger.…”