SwitchingValve33

Description

The component SwitchingValve33 is a model of a 3-way valve where the flow (at 100 % valve stroke) is set by NominalVolumeFlow and NominalPressureDifference.

For Input ≥ Input threshold to open the valve the valve switches in positive direction up to right position, for Input ≤ - Input threshold to open the valve the valve switches in negative direction up to left position. For - Input threshold to open the valve < Input < Input threshold to open the valve it switches into resting position (middle position).

The opening of the valve lasts always <>Time to open 0 % - 100 %<>, the closing always <>Time to close 100 % - 0 %<>, i. e. the switching from one end stop position to the other lasts <>Time to close 100 % - 0 %<> + <>Time to open 0 % - 100 %<>.

The valve stroke can be shifted by Valve edge general relative overlap. In accordance with common valve parameters a negative overlap will open the valve edge. Valve edge general relative overlap is applied to all valve edges simultaneously. If at least one of the edge-specific values, e. g. Valve edge PA relative overlap is set to a value different from 0, then Valve edge general relative overlap is ignored and the individual overlaps are used.

The default relationship between input signal and flow rate of the metering edge is linear, but can be changed through the use of a 1D look-up table. The look-up table is provided either manually or by importing a text file. If the parameter Table is provided by file is set to false, the manually entered datapoints from Manually provided look-up table will be used. If it is set to true, the table Table name on file from the file File where look-up table is stored will be utilized.

The text file must follow a specific syntax such that it can be read by Modelica. The input values as well as the output values must lie within the range from 0 to 1. An output value of 1 (100 %) corresponds to a fully-opened metering edge. An example for a properly formatted text file with two tables is given in the figure below:

A table is declared by its datatype (e. g. double), followed by the table name (e. g. tab1) and its dimensions in brackets (e. g. (5,2)). As can be seen, multiple tables can be defined in the same text file. The table declaration is followed by the actual data. The first column of the table represents the input of the 1D table, whereas the second column lists the corresponding output values. The input values of the table must be in increasing order. The component interpolates linearly between the listed input values. More information regarding the format of tables can be found at CombiTable1D.