Energy, Exergy, and Emission Analysis on Industrial Air Compressors

Abstract

Air compressors, a key fluid power technology, play an important role not only in industrial plants but also in office buildings, hospitals, and other types of facilities. The efficient use of the air compressor is crucial to control unnecessary inefficiencies that cause high energy consumption. This study aims to provide energy and exergy analysis on air compressors for different industries. Detailed case studies are also analyzed. The case study focuses on the energy and exergy analysis of the compressed air system of foundry industries. The results indicate that applying the six improvement recommendations yield significant amounts of energy and cost savings as well as significant improvements in the overall performance of the system. The payback periods for different recommendations are economically feasible and worthwhile to use. The suggested improvement methods can provide high costs with a low payback period.

A Review of Energy Overconsumption Reduction Methods in the Utilization Stage in Compressed Air Systems

“…At point 3, the actuator piston reaches its extreme position and stops. However, there is still an inflow of compressed air into the extend chamber, and the pressure increases to the supply pressure (3)(4). This means that one movement of the actuator will always consume air with a mass corresponding to the volume of the total chamber and the supply pressure.…”

“…Various strategies have been proposed to reduce energy consumption in the compressor. The proposed solutions are to reduce the outlet pressure [1,3,9,42,47,48], reduce the temperature of the intake air [1,3,9,42,47], recover heat [1,9,42,49,50], minimize the use of air [1,9,42,48], select the appropriate compressor [3,9,42,47], and use a variable-speed motor [1,49,51,52]. For example, in a study conducted by J. K. Bader [42], the exergy analysis of five different compressor modifications was explored: pressure reduction, reduction in intake air temperature, heat recovery, reduction in air consumption, and correct compressor selection.…”

“…This results in less load on the compressor or replacement with a smaller unit. Energy savings by selecting the appropriate compressor size for the pneumatic system can reach up to 49% [3,42].…”

“…The advantages of compressed air systems include simplicity, reliability, the ability to automate various processes, and a relatively low environmental impact [2]. However, a significant drawback of CAS is their relatively low energy efficiency, making compressed air the most expensive energy medium, more expensive than natural gas, steam, or electricity [3]. Energy efficiency is a measure of the usable energy compared to energy input, which indicates the amount of energy lost in a given process.…”

Exergy Analysis for the Intermittent Air Supply in Pneumatic Machines

“…Energy losses in CAS occur during compression, transmission due to leaks [5] and the utilisation stage through excessive air consumption [6]. Methods to improve efficiency in compressors and air leaks are well described in the literature and technology [7][8][9]. However, methods for reducing compressed air consumption are less well presented and can achieve an increase in energy efficiency by up to 40%.…”