From waste to hydrogen: An optimal design of energy production and distribution network

2010 ◽  
Vol 46 (4) ◽  
pp. 534-545 ◽  
Author(s):  
Nathan Parker ◽  
Yueyue Fan ◽  
Joan Ogden
Keyword(s):  
Optimal Design ◽  
Energy Production ◽  
Distribution Network ◽  
Production And Distribution

scholarly journals Optimal Design of District Metered Areas in a Water Distribution Network Using Coupled Self-Organizing Map and Community Structure Algorithm

Water ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 836
Author(s):  
Xuan Khoa Bui ◽  
Malvin S. Marlim ◽  
Doosun Kang
Keyword(s):  
Community Structure ◽  
Optimal Design ◽  
Water Distribution ◽  
Distribution Network ◽  
Coupled Model ◽  
Water Distribution Network ◽  
Self Organizing Map ◽  
Structure Algorithm ◽  
Demand Variability ◽  
Self Organizing

Operation and management of a water distribution network (WDN) by district metered areas (DMAs) bring many benefits for water utilities, particularly regarding water loss control and pressure management. However, the optimal design of DMAs in a WDN is a challenging task. This paper proposes an approach for the optimal design of DMAs in the multiple-criteria decision analysis (MCDA) framework based on the outcome of a coupled model comprising a self-organizing map (SOM) and a community structure algorithm (CSA). First, the clustering principle of the SOM algorithm is applied to construct initial homologous clusters in terms of pressure and elevation. CSA is then coupled to refine the SOM-based initial clusters for the automated creation of multiscale and dynamic DMA layouts. Finally, the criteria for quantifying the performance of each DMA layout solution are assessed in the MCDA framework. Verifying the model on a hypothetical network and an actual WDN proved that it could efficiently create homologous and dynamic DMA layouts capable of adapting to water demand variability.

scholarly journals Diversity, Community Composition, and Dynamics of Nonpigmented and Late-Pigmenting Rapidly Growing Mycobacteria in an Urban Tap Water Production and Distribution System

2013 ◽  
Vol 79 (18) ◽  
pp. 5498-5508 ◽  
Author(s):  
S. Dubrou ◽  
J. Konjek ◽  
E. Macheras ◽  
B. Welté ◽  
L. Guidicelli ◽  
...  
Keyword(s):  
Surface Water ◽  
Distribution System ◽  
Distribution Systems ◽  
Tap Water ◽  
Distribution Network ◽  
Water Production ◽  
Prevalence Index ◽  
Content Type ◽  
Rapidly Growing Mycobacteria ◽  
Production And Distribution

ABSTRACTNonpigmented and late-pigmenting rapidly growing mycobacteria (RGM) have been reported to commonly colonize water production and distribution systems. However, there is little information about the nature and distribution of RGM species within the different parts of such complex networks or about their clustering into specific RGM species communities. We conducted a large-scale survey between 2007 and 2009 in the Parisian urban tap water production and distribution system. We analyzed 1,418 water samples from 36 sites, covering all production units, water storage tanks, and distribution units; RGM isolates were identified by usingrpoBgene sequencing. We detected 18 RGM species and putative new species, with most isolates beingMycobacterium chelonaeandMycobacterium llatzerense. Using hierarchical clustering and principal-component analysis, we found that RGM were organized into various communities correlating with water origin (groundwater or surface water) and location within the distribution network. Water treatment plants were more specifically associated with species of theMycobacterium septicumgroup. On average,M. chelonaedominated network sites fed by surface water, andM. llatzerensedominated those fed by groundwater. Overall, theM. chelonaeprevalence index increased along the distribution network and was associated with a correlative decrease in the prevalence index ofM. llatzerense, suggesting competitive or niche exclusion between these two dominant species. Our data describe the great diversity and complexity of RGM species living in the interconnected environments that constitute the water production and distribution system of a large city and highlight the prevalence index of the potentially pathogenic speciesM. chelonaein the distribution network.

scholarly journals Optimal Design of a Helical Coil Support for Dewars in Fuel Cell Applications

2021 ◽  
Author(s):  
Baby Nitin ◽  
Pavitra Sandilya ◽  
Goutam Chakraborty
Keyword(s):  
Fuel Cell ◽  
Optimal Design ◽  
Mechanical Strength ◽  
Support System ◽  
Energy Production ◽  
Support Systems ◽  
Optimization Technique ◽  
Dynamic Loads ◽  
Helical Coil ◽  
Helical Coils

Abstract Fuel cells are gaining popularity because of their efficient energy production without causing environmental pollution. Recently DRDO, has developed a fuel cell-based fuel cell-based Air Independent Propulsion (AIP) system. In this system, the hydrogen is produced onboard while oxygen is carried in liquified form (LOX) from the land in specially designed insulated storage vessels called dewars. Such vessels are needed because LOX has low boiling point (NBP ~ 90K) and heat of vaporization (~213 kJ/kg) due to which it boils off easily even when there is small amount of heat inleak from the ambient. A typical dewar consists of two vessels separated by insulation. Support members are used to hold the two vessels together. Heat inleak through the supports and the insulation of the dewar causes the boiling of LOX. The vessels are subjected to dynamic loads during the voyage as well as due to the filling and consumption of LOX. Therefore, the support system should be designed so that it can withstand the dynamic loads experienced by the dewar. While the support system should have enough mechanical strength to withstand the loads it is subjected to, it should also restrict the heat inleak from the ambient to minimize the LOX boil-off. To meet this requirement, we need to optimize the support system design. Design optimization of support systems is especially critical in submarines to reduce the snorkeling frequency. Even though the dewars are available commercially for various applications, their design methodologies are not available in the open literature. Cylindrical rods are generally used as support members. In earlier studies, the authors have shown that helical coils give better thermal performance than tension rods as dewar supports. These two support systems involve different design criteria. It is important to evolve an optimal design of the support system to maximize the mechanical strength of the support while minimizing the heat inleak through the support. In this paper we are presenting a design methodology for optimizing a helical support. We have proposed a modified optimization technique derived from the classical genetic algorithm (GA) for this purpose. The modification has been done by ensuring design feasibility of the coil at each step of the algorithm. The proposed optimization technique has been tested on a LOX dewar and an optimal design of the helical coil support has been obtained.

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