Fins Free And Forced Convection Unit

The heat transport is substance-bound. The heat transport is substance-bound. In the convection process, the whole fluid is moving. So-called bulks of fluid move (and thus transfer heat) from warm zones into cold zones The different temperatures lead to density differences in the fluid so that a flow develops. In the case of free convection, the density differences result in a rather slow flow of the fluid with a more intensive heat transfer. In the case of forced convection, The flow is generated by a fan or pump. In this case, the heat transfer to fluid particles is lower, but more heat is transported than with free convection due to the much larger mass flow.
The core element of the experimental unit is a vertical duct into which a heating element is inserted. Three flows elements with different surfaces are available: a flat plate, a tube bundle Or fins. For experiments on forced convection, an additional fan has to be activated.
Sensors record the flow velocity of the air, the heating power and the temperatures at all relevant points.
The well-structured instructional material sets out the fundamentals and provides a step-by-step guide through the experiments.
Learning Objectives / Experiments
free and forced convection
heat transfer at different surfaces:
Flat plate
pipe bundle
fins
temperature distribution in the heat
determination of the Reynolds and numbers
calculation of heat transfer coefficient for free and
Forced convection
Technical details
Specification
heat transfer in the air duct by free and forced convection
air duct with axial fan
3 heating elements with different surfaces: flat plate, tube bundle or fins
sensors measure temperatures (upstream and downstream of the heating element and inside the heating element), flow velocity of the air and heating power
Technical Data
Air duct
flow cross-section: 120x120mm
height: 1m
Axial fan
max. volumetric flow rate: 170m3/h
max. pressure difference: 54Pa
power consumption: 6,5W
nominal speed: 2900min-1
Heating elements
temperature limitation: max. 150°C
max. heating power: 200W
surface of flat plate: 140cm2
surface of tube bundle: 980cm2
surface of fins: 1400cm2
Measuring ranges
flow velocity: 0...10m/s
temperature: 2x 0...100°C, 1x 0...200°C
heating power: 0...375W