Comparative Study on Continuous Compressed Air Flow Estimation: Pressure Decay Method vs Duty Cycle Approach

Abstract Compressed air is considered the fourth utility after electricity, water, and natural gas to power industrial processes. Due to its versatility, it has been used in more than 75% of manufacturing facilities across the United States. Unknown to manufacturers, in most cases, inefficient practices around compressed air systems often result in considerable energy and financial losses. Monitoring operational parameters is thus critical for detecting and diagnosing inefficiencies like leaks, artificial demand, inappropriate control, and unwanted usage of compressed air. Among the primary parameters used to monitor compressed air system performance are power consumption and pressure, both of which are relatively straightforward to measure. However, tracking compressed air flow, an equally important metric, is more challenging. Indirect measurement methods offer a viable alternative for estimating air consumption. By leveraging statistical approach to analyze power consumption trends and pressure fluctuations, continuous compressed air flow monitoring can be achieved. This paper explores and compares two distinct methodologies for estimating compressed air flow, one based on current consumption and another on system pressure profile. Estimations from both methods, are in close agreement to each other, with uncertainty of ±10%. Hence knowing pressure or current data can produce reliable consumption flow prolife. To illustrate the effectiveness of these methodologies, two case studies are presented. Furthermore, this paper provides insight into continuous compressed air monitoring in industrial systems, which has implications for enhancing energy efficiency and operational savings.