Because of restrictions on the size of the overall framework

heat exchangers with limited structure are called limited heat exchangers. Based on the limited model in air-handling unit

a lumped parameter model was established to study different performance of fin-tube heat exchangers. The dichotomy iteration was employed to solve the model. The results show that the model will not only design and calculate the number of tube rows along the airflow direction

but also analyze and predict the performance of fin-tube heat exchangers with variable condition and structure. The calculated results of the model were verified by the experimental data: the mean relative deviations are lower than 2% and the maximal relative deviations are lower than 8%. Experiments of enthalpy difference were conducted to analyze the heat transfer and friction characteristics of fin-tube heat exchangers with variable parameters

which optimize the design of the heat exchanger and provide the basis for the selection of heat exchanger operation method.