Software Development for Energy Assessments in Water Networks

Abstract

Energy assessment is one of the most important evaluations in water supply networks management. A water supply network is typically a large infrastructure that consumes a lot of energy to supply water with sufficient volume and pressure to users. An energy assessment in a water supply network aims to, therefore, determine the efficiency of the current system. Energy assessment follows the conservation of energy principle, which then requires to calculate energy balance. Initially, the energy into the system (E_in) is transformed into three energy elements: 1) the energy delivered to water users (E_U), 2) the energy exiting the system in a water loss form (E_l), and 3) the energy lost due to friction (E_F). Knowing the energy efficiency of each component facilitate plan making, management and decision making on appropriate strategies to increase efficiency, such as reducing water loss to reduce E_l, extension of pipe size to reduce E_F, etc. Traditionally, to calculate an energy balance, one has to extract results from the hydraulic model, which requires considerable resources. This research has developed a software that can assess energy by importing the hydraulics model of a water supply network from the EPANET program to facilitate energy balancing. The software has been validated using a water supply network model, the Office of the Metropolitan Waterworks Authority, Samut Prakan Branch. According to data of March 2018, it has been found that E_in, which equals to 36,920 kW-h/day (100%) has been converted to E_U 16,914 kW-h/day (45.8%), E_l is equal to 1039 kW-h/day (2.8%), and E_F is up to 18,967 kW-h/day (51.4%), indicating that pipe size should be increased to reduce E_F. This result shows a clear benefit of the developed software.