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RTC4Water - July 2017

Recently one of our close partners, the Syndicat des Eaux du Sud (SES), asked our team to assess how an automated network optimization system might reduce pressure fluctuations. While this request was a little outside of the scope of our normal activities, we readily agreed to look deeper into this question. But there was a catch: we had no pressure monitoring tools to guide our work.

 Pressure fluctuations: is this a problem?

Experts estimate that Europe has a water distribution network that exceeds 3.5 million kilometers. Naturally pipeline leaks are a serious concern for the industry and, by extension, so are the effects of pressure fluctuations on a network’s longevity. Research has determined that by deploying dynamic pressure management tools, organizations can expect a 10 to 15% savings on long-term capital expenditures[1]. But with budget and staff limitations, small or medium sized distribution networks may not have the ability to deploy and monitor wireless sensors or even install pressure reduction valves. For many organizations, finding additional support to implement cost efficient tools which extend the lifespan of existing infrastructure can be a difficult.

Where to Start?

As there were no pressure monitoring tools available, our team had to rely on the modelling tools and techniques that were already being developed for the client. SES was already concerned with finding new ways to create savings and so our team was already working with them to improve network efficiency without increasing operator workload. One section of their network was chosen and, once the mapping and modeling of the system was completed, a virtual environment was developed using EPANET and our Global Predictive Controller™ to dynamically test the network’s behavior with and without automated optimization. Specifically, an examination of the pressure fluctuations at the point of entry of the tanks was used to provide an indication of the expected reduction in pressure fluctuations.  It is interesting to note that SES uses advanced flow control valves on some of their inlet valves and these valves are set-up to have reduced maximum flows – one way to reduce pressure fluctuations. And as most of the receiving reservoirs in this section did not have a large difference in elevation, we knew that this test might not show extraordinary results.

Preliminary results

The Global Predicative Controller is designed to “smooth out” or homogenize the activity of all basins, pumps and valves within the network based on organizations goals such as reserved capacity levels, water quality or pumping costs. In theory, this homogenization should reduce the long-term stress on the distribution infrastructure. With only modelling data to work with, it is difficult to assign a “real world” number which quantifies these cost savings. However, our analysis did show that there would be a significant reduction in pressure fluctuations for all reservoir inlets. Below is an example from one of the reservoirs:

 

 

Since the difference in elevation between reservoirs for this test was not great, it cannot be said that the reduction in pressure fluctuations will have a large impact on the network’s lifespan. However, it is reasonable to accept that networks which operate under higher pressure conditions will see a significant benefit.

What can be said with some confidence is that the implementation of our system will improve the specific difficulty currently experienced here, which is that under certain conditions a reservoir may not receive a sufficient flow because other reservoirs are also filling up.

Exploring new technologies and looking for better ways to add value takes courage, and we are especially grateful to the SES team and Mr. Tom Levy for their support, not only as clients, but as experts dedicated to improving water quality. Mr. Levy was also instrumental to helping us present the technical results of this research at this year’s CEOCOR conference. Please see their website for the full abstract on this research and, as always, please contact us if you would like to know more about our products and services. We hope to repeat this analysis again using pressure data so please check out our Blog page from time to time if this topic is of interest to you.

 

[1] http://www.ee.co.za/article/advantages-water-pressure-management.html

Published in RTC4Water Blog