modelSteadyStateAnalysis

Information

Temperature distributions of the heat exchangers in cocurrent and countercurrent mode are given. T_H and T_c represent the temperature of the hot fluid and the cold fluid, respectively.

∆T represents the temperature difference between hot and cold fluids along the heat exchangers. And, x is a point along the channels of the heat exchanger. In the countercurrent mode, ∆T does not vary along the channels as much as the ∆T in the cocurrent mode. Moreover, in cocurrent mode, ∆T is very large at the inlet of the channels and getting smaller progressively. Countercurrent heat exchanger can be evaluated as more efficient with respect to cocurrent heat exchanger since countercurrent mode requires smaller heat transfer area to provide the same heat transfer rate.

At the steady state, the total flow rates of Q_A and Q_B is equal to a steady state rate equation and it is used for the verification of the models. Steady state heat rate equation for a heat exchanger is written as follows:

Q=UA∆Teog

UA=Lω(γ_A γ_B)/(γ_A+γ_B )

where L is the length, ω is the perimeter of the channels, γ_A and γ_B are the heat transfer coefficients of fluid A and B respectively.

Parameters

Components