Energy flow through an ORC turbine

An Againity ORC is usually installed open. The evaporator, turbine, generator, condenser and pumps are bolted to a frame and all of them are in plain sight, and none of that helps, because the vessels are sealed and the work happens to the fluids inside them.

The turbine goes into a heating plant that already exists. The plant burns wood chips, biogas or waste to heat water for a district heating network, and the ORC sits in that loop and takes electricity out of the water on the way past. The heat still carries on out to the network afterwards.

That is the part a customer has to believe before they buy anything. The heat is not spent, it passes through, and the electricity comes off the temperature drop in the middle. Municipal energy companies and plant operators are deciding whether to convert a plant they already own into combined heat and power, and there are more than 400 heating plants in Sweden with no electricity production at all, so it is a decision that comes up often and there is money in it.

The CAD came redacted. What was left had been triangulated into very uneven triangles, with shading artifacts across it, intersecting polygons, and loose polygons left behind where the proprietary parts had been taken out. Almost every part had to be remodelled before it would light or animate correctly. That was about a third of the production.

The turbine had to be rebuilt for a different reason. What the CAD showed was too specific to put on screen, and it is also the one component the film cannot leave out, so I remodelled it to read correctly as a turbine without showing detail that was not mine to show.

An engineer at Againity took me through how the process works and checked the animation for accuracy before the final render.

Opening the machine up is not the same as uncovering it, so I built a cross cut view of the components and animated the energy moving through them.

The film opens wide on the whole turbine, annotated only with heat in, heat out and electricity out. Then the camera moves in to the cross cut, where you can see inside the components and follow the flow through the turbine. The fluids are colour coded. Red is the hot water arriving from the boiler, blue is the cooler water going to and from the district heating network, and the working medium is green in both of its states. As it evaporates the green liquid breaks into particles, so the change from liquid to gas is something you watch instead of something you are told.

Showing direction inside a pipe was the awkward part. I gave the liquid a slight wave so the reflections carry motion, and put white markers travelling along the flow so the direction is unambiguous.

The film ends on a turntable, 45 degrees to the left round to 45 degrees to the right, counter clockwise.

Energy flow sequence · 46 s · 1920×1080
Overview, cross cut and turntable
MP4 masters in English, Swedish and Polish
Rebuilt and simplified geometry from client CAD

Againity used the animation on their homepage and on their YouTube channel, both on its own and inside the longer company film. It is still on the channel. The text graphics in the finished film were added by the agency running that production.

The company has since passed sixty ORC installations in Northern Europe.

Watch the finished film, the animation runs inside it.