A method of determining a fouling location of a shell and tube heat exchanger is provided. Under the method, a simulation model of the heat exchanger is partitioned into multiple segments. Each segment corresponds to a different one of multiple operating scenarios of the heat exchanger. For each operating scenario, temperature data and pressure drop data are generated from the simulation model of the heat exchanger. The fouling location of the heat exchanger corresponds to a respective segment in each of the multiple operating scenarios. The temperature data and the pressure drop data are classified based on the multiple segments of the simulation model by inputting the temperature data and the pressure drop data to one or more machine learning classification algorithms. The fouling location and a value of accumulated fouling at the fouling location are determined based on the classified temperature data and the classified pressure drop data.