In practice, different types of heat exchanger are used depending on requirements in order to ensure efficient heat transfer and avoid losses.
The WL 315C trainer is used to study and compare five different heat exchangers. Both parallel flow and counterflow operation are demonstrated, with their different temperature curves.
In the plate, tubular and shell & tube heat exchangers, heat is transferred between hot and cold water in tubes or between plates. In the finned tube heat exchanger, the air flows around pipes with hot water in crossflow.
In the stirred tank with double jacket and coiled tube, either the outer jacket or the inner coiled tube can be filled with hot water. A stirring machine ensures that the water inside the tank is mixed to achieve an even heat distribution.
The air volume flow for studying the finned tube heat exchanger is adjusted via a throttle valve at the fan outlet. Valves are used to switch between parallel flow and counterflow. The flow rate in the hot water or cold water circuit can also be adjusted by means of valves.
The air volume flow is measured with a fixed differential pressure sensor. The water pressure can be measured at different points using a portable differential pressure sensor. Temperatures and flow rates are also measured. The measured values are read from digital displays and can be transmitted simultaneously via USB directly to a PC where they can be analysed using the software included.
Hot and cold water is supplied either from the laboratory network or by means of the accessories WL 312.10 hot water generator and WL 312.11 water chiller.