Das Internet der Dinge im städtischen Abwassersystem : Potenziale der LoRa-Technologie für reichweitenkritische Anwendungen im Untergrund

Das Paper wurde im Download-Bereich der Konferenz "Internet of Things: vom Sensor bis zur Cloud" erstveröffentlicht: https://events.weka-fachmedien.de/internet-of-things.Hat Niedrigenergiefunk (LPWAN) das Potenzial die Prozessüberwachung in Infrastrukturen im Untergrund zu revolutionieren? Inwieweit eignen sich LPWANs, als neuartige Drahtlos-überragung des Internet-der-Dinge bekannte Technologie, für eine räumlich differenzierte und effiziente Langzeitüberwachung? Kann der etablierte LoRaWAN-Standard für reichwei-tenkritische Anwendungen angepasst werden? Grundlage für die Erörterung dieser Fragen sind einerseits unsere Erfahrungen seit Mai 2016 beim Aufbau und dem Betrieb eines Drahtlossensornetzwerks mit im Untergrund in-stallierten Sensoren in einer mittelgrossen Schweizer Gemeinde, und andererseits die dar-aus entstandene Neuentwicklung eines vermaschten LPWANs basierend auf der LoRa-Technologie. Im Einzelnen beleuchten wir i) die technischen Anforderungen an Sensorik und der Datenübertragungstechnologie für Anwendungen im Untergrund, ii) die Anwen-dungserfahrungen bezüglich Funkreichweite, Skalierbarkeit und Übertragungszuverlässig-keit, und iii) eine technologische Weiterentwicklung, welche die Reichweitenlimitierung ent-schärft und so eine effiziente Übertragung aus dem Untergrund ermöglicht. Unsere Untersuchungen unterstreichen die grundsätzliche Eignung des LoRa-WAN - Standards für eine Echtzeit-Über-wachung von Prozessabläufen im Unter-grund. Technologiespezifische Grenzen (Reichweite, Quality of Service) werden durch unsere Langzeitexperimente quan-titativ aufgezeigt. Die Neuentwicklung ei-nes vermaschten, LoRa-basierten Funks verbessert die Zuverlässigkeit der Über-tragung erheblich. Sinnvoll eingesetzt kann diese Neuerung einen wesentlichen Beitrag zur stabilen Prozessüberwachung von Infrastruktur im Untergrund leisten

The value of meta-data for water resource recovery facilities

[EN] Meta-data refers to descriptive information essential to convert large volumes of raw data into useful resources. With the advance of digitalisation in the water sector, it is fundamental to avoid data graveyards and, on the other hand, using collected data to address current and future problems. This white paper focuses on the crucial role that meta-data has in responding to future and possibly unpredictable challenges. The aim of this document is to present the `meta-data challenge¿ and to highlight the need to consider meta-data when collecting information as part of good digitalisation practices.Aguado García, D.; Blumensaat, F.; Baeza, JA.; Villez, K.; Ruano, MV.; Samuelsson, O.; Plana, Q. (2021). The value of meta-data for water resource recovery facilities. H2Open Journal. 1-15. http://hdl.handle.net/10251/188561S11

Synchronous LoRa Mesh Network to Monitor Processes in Underground Infrastructure

Collecting precise real-time information on urban drainage system performance is essential to identify, predict, and manage critical loading situations, such as urban flash floods and sewer overflows. Although emerging low-power wireless communication techniques allow efficient data transfers with great above-ground performance, for underground or indoor applications in a large coverage range are difficult to achieve due to physical and topological limitations, particularly in dense urban areas. In this paper, we first discuss the range limitations of the LoRaWAN standard based on a systematic evaluation of a long-term operation of a sensor network monitoring in-sewer process dynamics. Analyses reveal an-on average-five-fold higher data packet loss for sub-surface nodes, which steadily grows with increasing distance to the gateway. Second, we present a novel LPWAN concept based on the LoRaR technology that enhances transmission reliability, efficiency, and flexibility in range-critical situations through meshed multi-hop routing and ensures a precise time-synchronization through optional GPS or DCF77 long-wave time signaling. Third, we illustrate the usefulness of the newly developed concept by evaluating the radio transmission performance for two independent full-scale field tests. Test results show that the synchronous LoRa mesh network approach clearly outperforms the standard LoRaWAN technique with regard to the reliability of packet delivery when transmitting from range-critical locations. Hence, the approach is expected to generally ease data collection from difficult-to-access locations such as underground areas.ISSN:2169-353

A framework for modelling in-sewer thermal-hydraulic dynamic anomalies driven by stormwater runoff and seasonal effects

Rain-induced surface runoff and seasons lead to short- to medium-term anomalies in combined storm- and wastewater flows and temperatures, and influence treatment processes in wastewater resource recovery facilities (WRRF). Additionally, the implementation of decentralized heat recovery (HR) technologies for energy reuse in buildings affect energy-related processes across the urban water cycle and WRRFs heat inflows. However, quantitative insights on thermal-hydraulic dynamics in sewers at network scale and across different scales are very rare. To enhance the understanding of thermal-hydraulic dynamics and the water-energy nexus across the urban water cycle we present a modular framework that couples thermal-hydraulic processes: i) on the surface, ii) in the public sewer network, iii) in households (including in-building HR systems), and iv) in lateral connections. We validate the proposed framework using field measurements at full network scale, present modelling results of extended time periods to illustrate the effect of seasons and precipitation events simultaneously, and quantify the impact of decentralized HR devices on thermal-hydraulics. Simulation results suggest that the presented framework can predict temperature dynamics consistently all year long including short- to long-term variability of in- sewer temperature. The study provides quantitative evidence that the impact of household HR technologies on WRRF inflow heat budgets is reduced by approximately 20% during wet-weather periods in comparison to dry-weather conditions. The presented framework has potential to support multiple research initiatives that will improve the understanding of the water-energy nexus, pollutant dispersion and degradation, and support maintenance campaigns at network scale.ISSN:0043-1354ISSN:1879-244

A distributed heat transfer model for thermal-hydraulic analyses in sewer networks

Thermal-hydraulic considerations in urban drainage networks are essential to utilise available heat capacities from waste- and stormwater. However, available models are either too detailed or too coarse; fully coupled thermal-hydrodynamic modelling tools are lacking. To predict efficiently water-energy dynamics across an entire urban drainage network, we suggest the SWMM-HEAT model, which extends the EPA-StormWater Management Model with a heat-balance component. This enables conducting more advanced thermal-hydrodynamic simulation at full network scale than currently possible. We demonstrate the usefulness of the approach by predicting temperature dynamics in two independent real-world cases under dry weather conditions. We furthermore screen the sensitivity of the model parameters to guide the choice of suitable parameters in future studies. Comparison with measurements suggest that the model predicts temperature dynamics adequately, with RSR values ranging between 0.71 and 1.1. The results of our study show that modelled in-sewer wastewater temperatures are particularly sensitive to soil and headspace temperature, and headspace humidity. Simulation runs are generally fast; a five-day period simulation at high temporal resolution of a network with 415 nodes during dry weather was completed in a few minutes. Future work should assess the performance of the model for different applications and perform a more comprehensive sensitivity analysis under more scenarios. To facilitate the efficient estimation of available heat budgets in sewer networks and the integration into urban planning, the SWMM-HEAT code is made publicly available.ISSN:0043-1354ISSN:1879-244

Partitioning the impacts of spatial rainfall variability and climate variability in urban drainage flow modelling

ISSN:1029-7006ISSN:1607-796

Partitioning the impacts of spatial and climatological rainfall variability in urban drainage modeling

ISSN:1027-5606ISSN:1607-793