Characteristics of countercurrent flow heat exchangers

The paper includes equations described heat exchange in countercurrent flow heat exchangers. Taking the energy balance formula as a basis and dividing the heat exchanger into sections, the thermal balances of the cooled fluid, plate and heated fluid are prepared and pertinent system of three differential equations is derived. The E-NTU method is used in the analysis. Exemplary temperature profiles in steady state conditions are presented in a graphic form. Transfer functions and dynamic characteristic are determined. Response on step disturbance of inlet temperature is found. Responses on step or on sin disturbance of inlet temperature in steam condensation heat exchangers are found. The results of calculations are presented in a graphic form.