Modelling and experimental validation of a small scale trigenerative compressed air energy storage system
Abstract New advances in compressed air energy storage systems have been recently made especially regarding the use of heat generated from compression. On this basis, the concept of the trigenerative compressed air energy storage (T CAES) has recently been proposed. Many studies highlighted the feasibility and the benefits of this system to be placed close to the energy demand. The aim of this study is to examine a simple configuration of this system by a coupled experimental/modelling approach. This paper presents a detailed thermodynamic model of both the main components and the whole system. An experimental bench is used to validate the model and to investigate the effect of the operating parameters on the system efficiency and the model accuracy. The model predictions are consistent with the experimental measurements during the charge, storage and discharge phases. It has been found that the temperature drop across the pressure regulator should not be ignored and is governed by the Joule Thomson effect. Besides, it has been observed that the input temperature of the air motor must be accounted for in the assessment of future improved configurations. It was noted that the system efficiency increases significantly by adding the cooling and heating potentials. However, the round trip efficiency remains low at 15.6% Output values of the model are in good agreement with the experimental results with an error less than 13.2% The model can be applied as a basis for the performance assessment of prospective configurations and improvements of trigenerative compressed air energy storage.
Applied Energy