Kalyan R. Piratla

Estimation of CO2 Emissions from the Life Cycle of a Potable Water Pipeline Project

The accumulation of CO2 emissions in the atmosphere is considered a major contributor to climate change. Consequently, it is essential to control the emissions generated by human activities to protect the environment for future generations. Many countries have set their own emission control targets to achieve by the middle of the century. In this context, it is important to quantify emissions from human activity and consider alternatives in order to reduce these emissions. This paper demonstrates a model for estimating life-cycle emissions resulting from an underground potable water-line project that could be used as a managerial decision support tool. The life cycle of the water pipeline is divided into different phases for the analysis. Different methods are used to estimate the emissions in each phase of the life cycle. The results indicate the life-cycle emissions from a demonstration 152.4-m (500-ft), 200-mm (8-in.)-diameter water pipeline at a representative 1.22-m (4-ft) depth range between 1,463.2...

Quantification of Sustainability Index for Underground Utility Infrastructure Projects

AbstractThis paper examines environmental impact, costs, and social impacts comparing four construction techniques commonly used in the installation of underground utility infrastructure. The three impact factors are quantified to develop an overall underground sustainability index rating (USIR) for evaluating utility projects with competing installation technologies. The main contribution to the overall body of knowledge is the demonstration of a method for calculating a sustainability index that enables decision makers to quantify public works utility projects with guidance for evaluating proposed technologies based on environmental impact, costs, and social impact criteria. The aim is to help change the myopic thought process of typical public works owners who typically base contractor selection on lowest cost, rather than examining sustainability factors. An emission calculator was used in this research to quantify environmental impact by comparing six airborne emissions: carbon dioxide (CO2), carbon ...

Reliability based optimal design of water distribution networks considering life cycle components

Water distribution systems play an important role in supplying water to consumers in a timely and efficient manner. The importance and complexity of such systems lead to extensive research in the area of optimal design of water distribution networks. Traditionally, only system costs are considered in design with few models incorporating environmental impacts. This paper presents a model for designing sustainable water distribution networks by minimising life cycle costs and life cycle CO2 emissions, while ensuring hydraulic reliability for the life time of the system. The model integrates a multi-objective genetic algorithm with water network simulation software, EPANET. A traditional benchmark water distribution network is used to demonstrate the model. Eight scenarios have been developed to test and validate the model for a variety of objectives with different constraints. Trade-offs between life cycle costs and life cycle emissions, along with hydraulic reliability of the system are illustrated.

Criticality Analysis of Water Distribution Pipelines

An approach to evaluate the relative criticality of different pipes in a water distribution system is presented. To quantify the relative criticality of pipelines, a term, relative criticality index (RCI), has been defined and measured. RCI was developed by summing up the effects of reliability, cost of break repairs, and energy required to repair breaks in pipelines. These three components have been quantified and added appropriately to obtain an overall criticality index of pipelines in water distribution systems. The model is demonstrated by using a 9.4-square-mile area of a water distribution system comprising downtown Phoenix, Arizona. The overall system availability of the selected land use is found to be 46.6%, and the relative criticality index clearly indicates that galvanized steel pipes followed by regular steel and ductile iron pipes in the system are most critical (i.e., vulnerable). The analysis also presents predicted future costs and energy requirements to repair breaks in the water distri...

Nexus between distributed generation and urban water infrastructure

With the increasing penetration of distributed generation (DG) in distribution systems and the concern of energy efficiency, the nexus between electrical and water systems is becoming more apparent and strengthened via combined heat and power (CHP). This paper investigates the nexus between DG penetration and urban water infrastructure. The AC optimal power flow (ACOPF) based optimization model is used to assess DG capacity and determinate DG location. The IEEE 123-bus distribution test system is selected as the test bed and the corresponding water distribution network is developed based on the system cost minimization to constrain the thermal output utilized by water and to check node pressure head. The results indicate which bus in the system is suitable to place a DER and the capacity that can be accommodated by the system. Finally, the nodal pressures of water system are checked to see if the existing water distribution system could support the large penetration of DG.

Resilience Evaluation of Water Supply Networks against Seismic Hazards

AbstractIt is imperative that water supply networks (WSNs) continue to perform even after subjected to natural and anthropogenic hazards, and it is even more important in the case of earthquakes for fighting fires that usually follow. Past earthquakes have caused significant damage to WSNs rendering them dysfunctional and potentially threatening human survival. Although there has been a lot of research conducted in the past on the behavior of buried pipelines, there are few metrics and models that are readily usable for improving the performance of large WSNs prone to seismic hazards. This paper proposes an easy-to-use metric for quantifying resilience and an optimization framework for improving WSN resilience subjected to budgetary constraints. The proposed resilience metric is dependent on hazard intensity, estimated pipeline response, and network topology. The use of the proposed metric and the optimization framework are demonstrated on a large (1,874 pipelines and 1,474 demand nodes), real-world WSN i...

Pipe Criticality Analysis for Water Distribution Systems

An approach to evaluate the relative criticality of different pipes in a water distribution system is presented. To quantify the relative criticality of pipelines, a term “Relative Criticality Index (RCI)” has been defined and measured. RCI was developed by summing up the effects of reliability, cost of break repairs and energy required to repair breaks. These three components have been quantified and added appropriately to obtain an overall criticality index of pipelines in water distribution systems. The model is demonstrated by using a 9.4 square mile area of a water distribution system comprising downtown Phoenix, Arizona. The availability of the study area was estimated to be 46.6% and the relative criticality index indicates that galvanized steel pipes followed by regular steel and ductile iron pipes in the system are critical (i.e. vulnerable) for the system considered. The analysis also presents predicted future costs and energy requirements to repair breaks in the water distribution system for a 20 year analysis period. The results indicate that the expenditures to repair pipe breaks in the system for the analysis period is estimated to be

Comparative Evaluation of Topological and Flow-Based Seismic Resilience Metrics for Rehabilitation of Water Pipeline Systems

17.1 million. Additionally, the energy required to repair these breaks during the same timeframe would be 2,486 MWH. A Relative Criticality Index (RCI), along with future requirements of critical resources, should aid cities in better planning and managing of their water distribution systems.

MULTI-OBJECTIVE CRITERIA FOR THE OPTIMAL DESIGN OF SUSTAINABLE WATER DISTRIBUTION NETWORKS

AbstractWhereas the continuous functioning of water distribution pipeline systems is important during normal times, it is paramount in the event of disasters such as earthquakes that are usually fo...

Field assessment of a Vacuum Microtunneling (VMT) system for on-grade pipeline installations

Water distribution systems play an important role in supplying water to consumers in a timely and efficient manner. The importance of such systems, in addition to the complexity of their design, has led to extensive research in the area of optimal design of water distribution networks. Traditionally, only system costs are considered in design with few models incorporating environmental impacts. This paper presents a model for designing sustainable Greenfield water distribution networks with the objectives of minimizing life cycle costs, life cycle CO2 emissions, while ensuring hydraulic reliability for the life time of the system. The model integrates a multi-objective genetic algorithm with water network simulation software, EPANET, using Visual Basic for Applications (VBA). A traditional benchmark water distribution network is used to demonstrate the model. Six scenarios have been developed to test and validate the model for a variety of objectives with different constraints. Trade-offs between life cycle costs and life cycle emissions, along with hydraulic reliability of the system are illustrated. The result of this research is a model that can be used to design large, sustainable and reliable water distribution networks.