Abstract
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.
Highlights
Thermal-hydraulic considerations in urban drainage networks are essential to utilise available heat capacities from waste- and stormwater
Convective heat transfer at interface B is usually recognized as a relevant process
The approach that we propose applies the heat transfer model established in Section 3.1 and it creates a new computing module for the treatment of the temperature variable leading to a new simulation code called SWMM-HEAT
Summary
We formally define the concept of compartments and interfaces to be unambiguous and consistent, and we designate the term bulk liquid to use it – in foresight – globally for storm- and wastewater indistinguishably. Heat transfer mechanisms occur due to the interaction between the four following compartments: bulk liquid, pipe wall, sewer headspace and soil (see Supplementary Information (SI)-Fig. 1). B Bulk liquid-sewer headspace, and, C Sewer headspace-pipe/soil. Heat transfer related processes that develop at each interface (SIFig. 1) are:. Based on the previous heat related processes an overall energy bal ance equation of a sewer pipe section (Fig. 1) is defined by,. Specific mechanisms that may affect the heat balance to a lesser extent and under special circumstances, e.g., heat generated by biological, exogenous degradation processes and/or biofilm generation, are discussed there
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
