The convective heat transfer during pipe flow is determined by internal flow processes inside the tube and by heat conduction processes in the tube walls. With the WL 308 experimental unit, it is possible to study convective heat transfer on the pipe wall and inside the pipe of a tubular heat exchanger. Both parallel flow and counterflow mode with their different temperature curves are demonstrated in experiments.
The core element of the experimental unit is a double tube, which serves as the heat exchanger. Hot water is pumped through the inner tube. Cold water flows in the outer tube either in parallel flow or counterflow. The hot water emits part of its thermal energy to the cold water.
The non-linear temperature progression along the tubular heat exchanger is demonstrated by measuring the water temperatures in both tubes at the inlet, outlet and half of the transfer section. Measuring the tube wall temperature on the inner tube at half the transfer section allows the investigation of the convective heat transfer at the wall.
The closed hot water circuit contains a tank with electrical heater and a pump. Cold water is supplied and disposed of via the laboratory network. Valves are used to adjust the flow rate of hot and cold water.
The flow rate and all relevant temperatures are recorded and displayed on the experimental unit.