Characteristics of air cooling for cold storage and power recovery of compressed air energy storage (CAES) with inter-cooling

Abstract

A combined cooling and power (CCP) system driven by the compressed air energy storage (CAES) with inter-cooling is presented, and the air cooling is compared with that of an air compression refrigeration cycle (ACRC). The main objective of this paper is to evaluate the system performance, such as the volumetric flow ratio (VFR), the size parameter (SP), the ambient temperature, the temperature at the expander inlet, the power consumption of the compressor, and the power output of the air expander. The air discharge from the cold storage is used as the heat sink for air inter-cooling. Results show that the air expander can recover most of the power consumed by the air compressor. The air temperature at the expander outlet can be controlled by adjusting the air temperature difference (ATD) between the compressor outlet and the expander inlet, and the ATD is one of the main factors that influence the power output of the air expander and the net power consumption. To realize the air cooling for the cold storage, most of the power consumption of the compressor can be simultaneously recovered by the air expander. Compared with the ACRC, the air cooing by the air expander is superior for the ATD higher than 36°C. Overall, the CCP can recover most of the power consumption of the air compressor and realize the air cooling as a by-product for cold storage, which can be popularized in engineering applications.