Author: phineas

Publications

Sankey Diagrams for Material Flow Management

3 Comments on Sankey Diagrams for Material Flow Management

Mario Schmidt, a professor at Pforzheim’s University of Applied Sciences has published a paper on Sankey diagrams and their use in material flow management. The article, entitled “Der Einsatz von Sankey-Diagrammen im Stoffstrommanagement”, has two main sections: In the first part the author reviews how and where this type of diagrams have been used since they first appeared in a publication by Capt. Riall Sankey. This section also contains numerous samples: Sankey diagrams displaying the energy efficiency of the steam engine and of a 1911 a race car, material flow diagram from the iron and steel industries and many others. In the second part Schmidt elaborates on the methodology of Sankey diagrams and explains how extensions to the original Sankey diagrams (e.g. for cost flows or for material stocks) can be made.

The article is in German (sorry folks!), but according to Schmidt he’s working on an English publication…

Methodology

Java applet to explore Sankey energy diagram interactively

3 Comments on Java applet to explore Sankey energy diagram interactively

Researchers of the “energy flow” project at Weimar’s Bauhaus University have developed a Java applet to explore a Sankey energy diagram interactively.

Energy Flow Sankey Diagram, Bauhaus University Weimar

The accompanying explanation says:

We present a system that allows users to interactively explore complex flow scenarios represented as Sankey diagrams. Our system provides an overview of the flow graph and allows users to zoom in and explore details on demand. The support for quantitative flow tracing across the flow graph as well as representations at different levels of detail facilitate the understanding of complex flow situations.

The energy flow in a city serves as a sample scenario for our system. Different forms of energy are distributed within the city and they are transformed into heat, electricity, or other forms of energy. These processes are visualized and interactively explored. In addition our system can be used as a planning tool for the exploration of future scenarios by interactively manipulating different parameters in the energy flow network.

The Java-based online version (in German) allows the visitor to interactively explore the Sankey diagram. They can zoom in, move the nodes, or call additional data for individual layers.

General, Samples

Energy Losses in Industrial Ceramic Furnace

Here are two Sankey diagrams that show the energy losses in an industrial ceramic furnace. The diagrams are oriented top-down. The labels are in German.

The Sankey diagram in blue shows the energy use in an industrial ceramic furnace. The flows are shown in absolute values and in percentage values.

sankey furnace energy loss percent-v1

The second diagram in red is similar to the blue one, but it only show the relative flows in percentiles. Additionally the flows entering the diagram at the top have been separated to show their shares. Other flows (‘Rest’) have been grouped together and the individual contributions are shown on the label.

sankey furnace energy loss percent-v2

Samples

Energy Balance for Stoves in Indian Silk Industry

This article on the FAO website shows a comparison of several types of simples stoves and their energy balance using Sankey diagrams.

A stifling stove for cocoon cooking in India

The Sankey diagrams show how the energy (typically from wood firing) is lost, and that only a small fraction of 12 to 20 % is actually being used as “useful heat”.

Heat loss of stove (original Sankey diagram by FAO)

More of these “heat flow diagrams” can be found in chapter 4.2. of the article.

A rather special feature of the diagrams shown in this article is that the percentile values given for the flows cover a range (e.g. Ash and Char 5,97% – 12,15%), rather than a specific absolute value. This is rather untypical. Also, it can be noted, that the width of the arrows are not always to scale: compare, for example, the width of the “Surface” arrrow to that of the “Thermal Mass” arrow. It should be roughly four times wider.

The same Sankey diagram created with a Sankey software tool shows the arrow widths correctly.

Heat loss of stove (remake of original Sankey diagram)
General

Sankey Diagrams – a new kid on the blog

Welcome to Sankey Diagrams, a blog about a special type of flow diagram, that allows to represent material, energy or cost flows.

We will be presenting samples of Sankey diagrams and tidbits of information on these flow charts, widely used in engineering, especially in the energy field.

Of course we welcome your suggestions and comments. Do you have a Sankey diagram to share with the readers of this blog? Feel free to contact us.