Optimizing Pump System Energy Efficiency Using a Piping System Digital Twin and Integrated Pump Selection

Optimizing system efficiency for motor-driven fluid handling equipment continues to be a major source of cost and energy savings for owners and operators of pumps, compressors, blowers, fans, and other rotating equipment. Recent legislation such as the Ecodesign requirements for water pumps and the United States Department of Energy (DOE) legislation focused on specific types of pumps or fans sold in the USA to offer new energy efficiency metrics for purchase of new equipment. The method of True Weighted Efficiency (TWE) was later developed to offer a single efficiency metric applicable to any rotating machine operating under multiple operating conditions. These methods are valuable and confidently applied to extended products. Most energy savings opportunities apply to existing installed systems. Pumps are often oversized to accommodate worst case design conditions leading to suboptimal efficiency at normal operation. Further, operating conditions change over the lifespan of a pump system, often justifying the replacement or retrofit of the existing system with new pumps or system control methods. This requires energy efficiency analysis of the entire system, including the extended product (pump, motor, and control system) and the accompanying piping system network. These problem domains are typically analyzed separately using piping system analysis software, a pump selection optimization product, and calibration with operating data acquired over a specified time horizon. This paper examines pipe system analysis integrated with the actual selection of alternative pump-motor-control systems. A digital twin of the existing pump and piping system is developed and empirically adjusted to accurately model the actual performance data provided from on-site sensors. Once the digital twin is accurately calibrated to field sensor data, different system design modifications are evaluated to assess alternative energy-efficient scenarios. Three case studies are used to demonstrate a pipe system analysis with integrated pump selection to optimize the pump system and piping network. The goal of the paper is to promote awareness and broad application of this integrated method for industry practitioners working with motor-operated fluid handling equipment.