WIND TURBINE DYNAMICS

The wind tunnel that the turbine is mounted in has a bell mouth and honeycomb for flow settling on the inlet. Speed is measured by an anemometer that is stowed away when not in operation so the flow is not disturbed. The turbine can be viewed from both sides of the tunnel through a transparent window and a sliding door with an interlock. The turbine features motorised blade pitching and digital read-back so down time during experiments is reduced.

Attached to the base of the turbine is the yawing mechanism and the setting handle. The turbine is compatible with custom-designed 3D-printed blades built upon the hub CAD file provided by IMPACT. A removable silencer is attached to the rear of the wind tunnel to reduce noise pollution. The silencer can be stowed beneath the apparatus to reduce space when it is stored.

The built-in safety features include an interlock on the door so that it can’t be opened while the turbine is turning and a smart shut down system that isolates power to the turbine in the event that over current or over speed is detected.

The control box has two screens for standalone operation and a VDAS® output for connecting to a PC via USB. Controls for the operation of the product are on the top panel for:

• Door open (Interlock release)

• On/off buttons

• Wind speed

• Turbine speed

• Turbine pitch

PHOTOVOLTAIC CELLS

Shows students the working principles and performance of a photovoltaic cell array and battery storage system.

It uses a commercially available solar panel made from high efficiency cells. The solar panel is on a wheeled, lightweight frame that allows adjustment of panel angle, relative to the sun. A solarimeter on the frame measures incident radiation.

The panel recharges a choice of two batteries through a charge controller. The charge controller recharges the battery at the correct rate of charge without damage to the battery. The frame holds a high performance deep cycling battery in a storage box.

The equipment also includes a second lower rated battery. This allows students to examine the charge and discharge cycle of the system in a typical laboratory session. A control module contains the charge controller. The control module has digital displays and shows the panel and battery storage performance. It has indicators to show when the charge controller is in float mode and load cut mode. It also has two power outputs. Output 1 allows direct connection of external loads to the solar array, for direct load experiments. Output 2 allows connection through the charge controller to show how it works with a load and a battery.

A separate loading unit includes:

• A variable resistive load to show battery performance.
• An inverter to show practical conversion to AC voltages.
• Four switchable lamps to show a practical application.

The equipment works with IMPACT’s Versatile Data Acquisition System (VDAS-B, not included). IMPACT’s Versatile Data Acquisition System allows accurate real-time data capture, monitoring, display, calculation and charting of all the important readings on a computer.

FOCUSING SOLAR ENERGY COLLECTOR

A focusing solar energy collector on a mobile frame. Specially designed for educational use, the apparatus shows the principles, advantages and limits of this method of capturing solar energy.

It is a highly-polished stainless steel parabolic reflector, supported on trunnion bearings on a turntable. By adjusting the horizontal and vertical position of the reflector, students focus solar energy onto an energy collector. The energy collector is a copper cylinder with an embedded thermocouple that measures the cylinder temperature.

To enable students to compare different concentration ratios, IMPACT supply four different sizes of energy collector. Also supplied is a removable transparent cover for the collector, so students can study the properties of shielded and unshielded collectors.

Attached to the reflector carrier is a solarimeter (pyranometer) that measures the incident solar radiation. An extra thermocouple measures ambient temperature for reference.

The cylinder thermocouple, the solarimeter and the ambient temperature thermocouple connect to a Display Unit. The Instrumentation Unit shows ambient temperature, collector temperature and solar intensity from the solarimeter. It also has a socket for connection to IMPACT’s optional VDAS®.

The equipment works with IMPACT’s Versatile Data Acquisition System (VDAS-B, not included). IMPACT’s VDAS® allows accurate real-time data capture, monitoring, display, calculation and charting of all the important readings on a computer.

This equipment shows how a flat plate solar energy collector works. It allows students to measure and find the efficiency and heat losses of a flat plate solar energy collector.

The collector has a purpose designed and built panel for quality and reliability. The panel has a thin sheet metal absorber backed by riser tubes and insulating material to reduce heat loss to the rear. A box with a clear cover encloses the panel, forming the collector. A sturdy mobile frame supports the collector. To allow users to adjust its angle, the frame has a hinge.

Cold mains water enters the collector. Sunlight energy heats the water in the collector. The heated water returns to a pump that mixes the heated water with the incoming cold water. A pressure sensitive valve allows the heated water to leave the equipment at the same rate as cold water enters it. A flow transducer measures the water flow rate and a solarimeter (or pyranometer) measures incident radiation.

Thermocouples measure the water temperature at all the important points, and the shade temperature. The separate Instrumentation Unit displays the temperatures from the thermocouples, the flow rate and the radiation intensity. It includes a switch to control the pump and a socket for connection to IMPACT’s optional VDAS®.

For quick and reliable tests, IMPACT can supply the optional VDAS® (Versatile Data Acquisition System). VDAS® gives accurate real-time data capture, monitoring and display, calculation and charting of all the important readings on a computer. To compare efficiencies, the Flat Plate Solar Energy Collector is an ideal companion to IMPACT’s Focusing Solar Energy Collector (TE38).