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PWN
Heemskerk, Netherlands

Bakker M.,Technical University of Delft | Van Der Made K.-J.,Wiertsema and Partners | De Haas S.,PWN
Water Resources Research | Year: 2015

A new approach is developed to insert fiber optic cables vertically into the ground with direct push equipment. Groundwater temperatures may be measured along the cables with high spatial and temporal resolution using a Distributed Temperature Sensing system. The cables may be inserted up to depths of tens of meters in unconsolidated sedimentary aquifers. The main advantages of the method are that the cables are in direct contact with the aquifer material, the disturbance of the aquifer is minor, and no borehole is needed. This cost-effective approach may be applied to both passive and active heat tracer experiments. An active heat tracer experiment was conducted to estimate horizontal groundwater velocities in a managed aquifer recharge system in the Netherlands. Six fiber optic cables and a separate heating cable were inserted with a 1 m spacing at the surface. The heating cable was turned on for 4 days and temperatures were measured during both heating and cooling of the aquifer. Temperature measurements at the heating cable alone were used to estimate the magnitude of the groundwater velocity and the thermal conductivity of the solids. The direction of the velocity and heat capacity of the solids were estimated by including temperature measurements at the other fiber optic cables in the analysis. The latter analysis suffered from the fact that the cables were not inserted exactly vertical. The three-dimensional position of the fiber optic cables must be measured for future active heat tracer experiments. Key Points Fiber optic cables are inserted into the ground with direct push equipment Temperature is measured along vertical fiber optic cables with DTS unit Active heat tracer experiment is carried out to estimate groundwater velocities © 2015. American Geophysical Union. All Rights Reserved. Source


Worm G.I.M.,PWN | Worm G.I.M.,Technical University of Delft | Wuister J.J.G.,Royal HaskoningDHV | Van Schagen K.M.,Royal HaskoningDHV | Rietveld L.C.,Technical University of Delft
Journal of Water Supply: Research and Technology - AQUA | Year: 2013

This research adds a method to evaluate control strategies to the design methodology for drinking water treatment plants. A process model dealing with parameters related to the calcium carbon dioxide equilibrium was set up. Using the process model, the existing control strategy was compared with a new control strategy and the effects of two different sets of input data were studied. It was demonstrated that the efficiency of the pellet softening process and the plant's capacity were increased, and that chemicals and energy usage were reduced. At the same time, the deviation of the total hardness of the produced water to the desired value was decreased. © IWA Publishing 2013. Source


Worm G.I.M.,PWN | Worm G.I.M.,Technical University of Delft | Kelderman J.P.,PWN | Kelderman J.P.,Technical University of Delft | And 4 more authors.
Water Science and Technology: Water Supply | Year: 2013

This research deals with the contribution of process simulation models to the factory acceptance test (FAT) of process automation (PA) software of drinking water treatment plants. Two test teams tested the same piece of modified PA-software. One team used an advanced virtual commissioning (AVC) system consisting of PA-emulation and integrated process simulation models. The other team used the same PA-emulation but basic parameter relations instead of the process simulation models, the virtual commissioning (VC) system. Each test team found one (different) error of the 13 errors put into the software prior to the experiment; most of the errors were found prior to the functional test. The team using the AVC-system found three errors, the team using the VC-system found four, but the AVC-team judged 1% of the test items 'not possible', the VC-team 17%. It was concluded that the hypothesis that with AVC more errors could be found than with VC could not be accepted. So, for the FAT of PA-software of drinking water treatment plants, the addition of basic parameter relations to PA-emulation was sufficient. It was not the exact process behavior that helped to find errors, but the passing of process thresholds. © IWA Publishing 2013. Source


Beuken R.,KWR Watercycle Research Institute | Horst P.,PWN | Diemel R.,Brabant Water | Mesman G.,KWR Watercycle Research Institute
Procedia Engineering | Year: 2014

The total length of the drinking water distribution network in the Netherlands is approximately 117,000 kilometers. The total replacement value is estimated at 20,000 to 30,000 million Euro. Several methods are available to obtain information to determine which mains should be replaced and when. Recently the echopulse technique was introduced in the Netherlands. The echopulse results were compared to phenolphthalein staining tests and radar. The validation of results reported here shows that the echopulse method provides reliable results for AC mains. However, a prerequisite for reliable results is the availability of reliable data on the properties of the mains, especially the initial wall thickness and the Young's modulus. © 2014 Published by Elsevier Ltd. Source


Van Thienen P.,KWR Watercycle Research Institute | Vries D.,KWR Watercycle Research Institute | Vries D.,Center of Excellence for Sustainable Water Technology | De Graaf B.,Vitens | And 3 more authors.
Procedia Engineering | Year: 2014

In this paper, we investigate the relevance of the stochastic nature of water demand for backtracing of contaminations in drinking water distribution networks. We present an approach to deal with the uncertainty introduced by stochastic demand, which is applied to a full detail part (all pipes) of a hydraulic model of a distribution network in the Netherlands. It is demonstrated that stochastic water demand can introduce significant amounts of uncertainty for backtracing in some parts of tertiary (reticulation) networks in specific, looped configurations. In other parts, the additional uncertainty introduced by stochastic water demand can be limited. © 2013 The Authors. Published by Elsevier Ltd. Source

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