After the start of the program the table sheets for pipes, pumps and knot (fig. 1) appear.
The input can take place in the respective input mask (white input fields to the left of the yellow table) and operate then through the Buttons adding into the table to be shifted.
If all input data of all table sheets were shifted into the tables, with the Button finishing in the table sheet of the knots the file for the computation procedure is finished and stored.
Once finished input files can be called with the instruction working on, project again.
The computation is accomplished with the instruction working on, calculation. The expenditure of the results takes place tabular in a further window.
Abbildung1:
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All
inputs can be settled also with the graphic input support (GEU). In the
GEU can schematized flow patterns provided (drawing mode) and be
nummeriert automatically. In the connection the strands and pumps in
the “data input mode” the numberings will through
click into the input mask of the main program will transfer. Step 1 Click on the symbol of the GEU. It opens an additional window with a 2D Grid Step 2 Change into “drawing mode” Step 3 Select first the knot symbol. All Gridfelder to be now clicked receives a knot. Proceed exactly the same with the strands and pumps, until the system pattern is finished. On the left of no element selected to separate if the white field is clicked, those can be deleted element. |
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Step 4 With execution of the “numbering” the knots, strands and pumps are durchnummeriert. Numbering direction is from left to the right above down. There the pump direction of flow by the knot numbering is determined is if necessary by hand the numbering accordingly to be supplemented. This is the case if pump symbols with direction of flow was upward or to the left selected. Then the numbering direction should have turned around. The change can change “number” with the instruction to take place. But best one schematizes in such a way, which the pump symbols show to the right or downward. Then one does not need to change anything. Step 5 After the change in the “Dateneigabemodus” first z becomes. Ex. the strand Nr.1 in the 2D Grid clicked. Those available numbering data (strand number, Anfangsknotennr., end node number) are transferred thereby into the input mask of the main program. Length, diameters, Ks-value and single losses are to be still supplemented then. By clicking the Buttons “adding” the values of the strand are transferred into the data base. In the following all strand data can be transmitted in the same way. Similar can be proceeded with the pumps. Step 6 If all strands and pumps are entered, “Knotnumakt” (knot numbers to update) can be transferred all used knot numbers into the table sheet “knot” with the Button |
Step 7
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Data in-giving input “strand”
The
pipeline which can be examined is divided into strands. A strand
consists of a pipe without branches with constant diameter.
The strands are interconnected at points of coupling. The points of
coupling are called knots.
The input values for each strand are:
Strangnr.
Anfangsknotennr. AKN
Endknotennr EKN
L in m lengthens
Diameter DN in mm
roughness concerned ks in mm
The initial knot number must be ever smaller than the end node number, since otherwise the pressure loss computation with an error message is occupied.
The water flows from the end node to the initial knot the quantity river as negative result is spent.
Armatures and shaped parts can to be seized be able to be taken over “Zeta values”, those the technical literature, and/or in the program a Pulldownmenue. The Zeta values can be added to the respective strand or be entered as separate strand.
The numbering of the knots is to be made with larger nets in form of a border moving over the drainage system. Thus the matrix of the set of equations receives a bandförmigen character, so that as good a convergence as possible is reached. The knot numbering can take place for example in 10er steps, then the possibility exists to insert afterwards knots. One does not select a numbering without sufficient distance exists this possibility and with one later necessarily becoming change must that net is again nummeriert and is completely again entered.
Through click the 1. Line in the table can be accomplished an assortment up or downward after line number, strand number knot number, length, DN or ks. With the computation of additional variants of the pipeline or with subsequent restructuring the again which are added strands are in the first free line after the lines already occupied always anzuordnden.Input of the pump data in the table sheet „pump “
Centrifugal pumps find over an approximation of the pump characteristic after “Hermite” as “spline-curve” in the net consideration (S. fig. 2) and are separate by knots from the strands.
The input values for each pump are:
Pumpennr.
Anfangsknotennr.
Endknotennr.
Hoisting depth of h in m (min. of 3 and up to 8 basic values of the pump characteristic)
Flow rate Q in l/s (min. of 3 and up to 8 basic values of the pump characteristic)
The operating point of the pump lies between the first and second basic value in the tabular expenditure for result is indicated that the operating point lies outside of the optimal range. During the input the basic values should be selected as in such a way as possible that the optimal work area begins only after the second basic value.
Input of the knot data in the table sheet „knots “
Boundary conditions must be assigned to the system such as pressure defaults, quantity feeds.
Is at least one indication of pressure height as well as at least one quantity feed and/or /-entnahme at another knot than the pressure height default necessary, or an indication of pressure height in the inlet and one in the expiration.For the respective knots the quantity feed and/or quantity withdrawal is to be entered. Knot, at which an indication of pressure height is already present becomes the actual quantity feed and/or - withdrawal of the program calculates, a quantity specification is unnecessary therefore at this knots.
The
fields at those will not be present boundary conditions concerning
quantity feed and/or - withdrawal, or well-known pressure height simply
released.
Tap:
With the Button Knotnum
act. (Knot numbers update) will all knots in the table
sheets the pipe and pump were entered in the correct order to transfer.
The further boundary conditions can click then directly in the table
through the respective field to be entered. In the framework by
restructuring of the pipeline strands and/or pumps are deleted or come
further strands /Pumpen in addition are first the knots if necessary
which are void to delete (over search
knot and removing)
and to it with Knotnum
act. the additional knots add. Afterwards the appropriate
boundary conditions at the new knots are to be inserted.
Results
The results are tabular spent. The expression and the further treatment can be made in the editor inside the program and/or are by the program “WORD”, “Excel” or “WordPad” o. ä. possible
Results for strands are: Results for knots are:
Flow rate energy height
Direction of flow and discharge quantities
Speed
Pressure loss
Results of the pumps are:
Delivery
Hoisting depth
The hoisting depth is spent as negative value, i.e. the negative loss of energy corresponds here to the energy gain by the Pumpenleistung.
There is the possibility for the production of hydraulic lengthening cuts (S. fig. 3)
Illustration 3:
Special characteristics of the program
As here is the case for each computation program also, (in particular with larger nets with high cross-linking degree) a plausibility check of the results should be accomplished. Before the background that so far only little practical experiences are present concerning the computation results, is control of special importance. A guarantee for the correctness of the results is not given.
