In this video we want to show you the tools you have in our Aqueducts software to determine the minimum useful volume in Water Distribution Storage Tanks, considering not only the storage for supply or equalization, but also additional storage such as fire protection, among others.
You will see in the list of options available within the design button, the one corresponding to Capacity Calculation of Storage Tank.
Before using this option, it is important that you have already done the design of the water network by clicking the Calculation or Design button in order to update the corresponding water demand, and ensuring that the base calculation hypothesis is active.
Now, it is time to click the button to show the following dialog.
Here you will see, in the Equalization Storage tab, a box where the method of calculation of this volume can be selected.
By default, the mass curve method is active. In this method, the amount of equalization storage required is obtained through the comparison of the production rates with a typical day demand pattern. The area between the respective curves will be the equalization storage.
And, if your country’s regulations require it, you will see that there is also the option of calculating this equalization volume by entering a fraction or percentage of the mean daily water demand associated with the water network supplied from the storage tank.
Below, we have the box where it is required to specify which mean water demand will be used with the aforementioned methods.
The actually active one is the one that will use the mean flow calculated by the software for the whole water distribution network. Note that in this box the value is expressed as liters per day.
But, if you want to enter your own value, you can use the user defined option and enter the desired value in this text box.
I’ll keep the first option and, by clicking this button, the calculation is made, in this case, based on 30 percent of the network’s mean daily water demand.
Note that, in each calculation, the total volume is also updated, including the other uses that we will see later.
But let’s talk about the mass curve method which has, in fact, more information to take into account in order to be able to determine the equalization volume in a way that is more in line with the real conditions of the water network.
When I activate it, you will notice that the table on the right becomes enabled as well as these controls above.
From this table, the columns with the percentage symbol in the header are editable. In the Effluent percentage column, you must enter the values, as a percentage of the average flow, of the demand curve of the water network for the 24 hours of the typical day. It is the one that represents the flows that will be extracted from the storage tank.
Then, in this column, you must specify, also in percentage of the average flow, the values of the storage tank’s inflow curve. In other words, the amount of water that the source of the tank—a pumping station, for example—guarantees throughout the typical day.
For example, we have incorporated an option in which it is assumed that the inflow is a constant rate equal to the average flow of the network. Note that all values are 100 percent.
If this is the case for the water network, then simply click on the calculate button to update the accumulated volume data and, to show the respective cumulative volume curves, click this button to the right.
You will see the inflow curve in blue and the effluent one in red, just as we learned in university.
It is worth saying that you can give this graphic the format that best suits your preferences through these options here.
Then you can save it as an image or print it using these two buttons.
Let’s close here to show you more features of this dialog.
Here, in the upper part, you have seen a list of inflow Condition or curves as well as three buttons to add, delete, and edit them to the project.
The idea here is to be able to create and keep several inflow curves in your project and thus have the option of studying the differences between the storage volumes obtained for each case.
Suppose that the supply of the daily demand to the tank is carried out only in 8 hours. Let’s say that the tank is supplied from a pump.
In that case, I am interested in creating an inflow curve that reflects the values corresponding to this operational condition.
So I click the add button, and in this dialog I enter a name to differentiate it from the previous one.
This box allows you, optionally, to fill the values of this new curve for different ranges or groups of hours.
Remember that, in any case, once created, you will be able to modify your values one cell at a time.
But this option allows me to save a little work. So I add a row and specify the eight-hour range of this example, with the corresponding percentage of the average flow to be supplied.
When clicking OK, the dialog is closed and you will see the values of my new inflow curve within the table of volumes.
I’ll update the calculation to get the new equalization storage volume.
And, to allow you to see it better, I’ll show the accumulated curves.
It’s quite simple, as you will see.
As I said, you will always have here the inflow conditions that you have evaluated, and you can select them individually and, if you wish, present the values in the table and export them to Microsoft Excel or print them by clicking this button.
Finally, let’s look at the Fire and Emergency Storage tab.
Here you will find the field and options to calculate the storage volumes that could be, from the operative or normative point of view, additional to that of equalization storage.
So we have included in the left box the options to determine the fire storage.
In this specific case, we consider the option in which the applicable design codes specifies a duration of the fire, which by default is of two hours in the software, as well as a fire demand or fire flow which, generally, is the same one that we used in the verification of the network at the most unfavorable hydrant.
Here we have it at 16 liters per second.
A variant is that you directly enter, by activating the second option, the fire storage volume.
Of course, in each modification, it is necessary that you click the update button, in order to obtain the respective volume as well as the total down here.
Then, to the right, we have the box with options to consider emergency or contingency storage, such as faults in the supply to the tank.
In this case, we have three options.
The first one allows you to calculate the storage as a percentage with respect to the water network mean demand.
The second considers that the volume is obtained as a percentage of the mean inflow to the storage tank.
This would be the case in tanks supplied from pumping stations where, because of their vulnerability, there could be mandatory a storage calculated as the percentage of the mean daily pumped flow.
And, finally, in case none of the previous options suit your requirements, there is also the option of entering the value you consider appropriate for this storage.
Again, as you can see, you have in AQUEDUCTS a tool, if you will, that is quite didactic for calculating the useful volume of the water distribution storage tank of each network that you project with our software for the design of water distribution networks.
Thanks for your attention.