T7 in a stirling engine dynamometer

This is a good example of how LabJack devices are used in the wild. Martin Beck, an engineer working with VE Engineers in Germany, employed the T7-PRO for data acquisition within a dynamometer. The dynamometer is used to measure the output from a stirling engine.

Signals Acquired

  • Eight (8) temperatures through Type K Themocouples. Directly connected to T7-PRO´s CB37 board without further amplification. Sample rate = 1 Hz. CJ compensation via LM34CAZ.
  • Torque, ±50 Nm. Output of torque-gauge ±10V. Directly connected to LabJack T7-PRO. Sample rate = 1 kHz.
  • Absolute internal pressure, 0-20 bar abs. Output of pressure-transducer 0-10V. Directly connected to LabJack. Sample rate = 1 kHz.
  • Crankshaft angle and velocity. Incremental encoder with quadrature output. 360 tics per rev max. 36 kEdges per sec. Directly connected to LabJack. Counter is quadrature-counter. Sampling of Counter-value with 1 kHz. Resetting of counter through inductive initiator.

T7-PRO in the dyno electronics enclosure

A view of the electronics enclosure on the side of the engine/dyno.

Dynometer view 1

The engine setup

Dynometer view 2

Another view

Dynometer view 3

Close-up of the engine

stirling engine heat source

The heat source for the stirling engine exposed for viewing.

Much information is derived from the acquired data, such as thermal and mechanical power, efficiency, etc. Quite a few graphs are automatically generated, such as high speed data over time and over crankshaft angle; p-over-V diagram; Power, Torque, Efficiency over velocity, etc.

The application was programmed in LabVIEW using the LJM Library and LJM LabVIEW example code. Other active components are a frequency-inverter from SEW-Eurodrive and a temperature-controller from Watlow. Both with ModBus/TCP interfaces. This makes a very neat system-concept, with just one Ethernet-cable coming out of the machine, for the entire control and data-acquisition.

2 comments

martin beck mechatronic's picture

Videos are not really great, but here you can see the biest in action:

https://www.youtube.com/watch?v=O3KqTUR5y9g

https://www.youtube.com/watch?v=NLDJTWXv0Rc

Enjoy!

Greetings from Germany,

Martin

LabJack Support's picture

Thank you for the videos.