Thermodynamic analysis of a novel compressed carbon dioxide energy storage system with low‐temperature thermal storage

Abstract

Summary Research projects on new electrical energy storage (EES) systems are underway because of the role of EES in balancing the electric grid and smoothing out the instability of renewable energy. In this paper, a novel compressed carbon dioxide energy storage with low‐temperature thermal storage was proposed. Liquid CO2 storage was employed to increase the storage density of the system and avoid its dependence on geological formations. Low‐temperature thermal energy storage technology was utilized to recycle the heat of compression and reduce the challenges to system components. The system configuration was introduced in detail. Four evaluation criteria, the round trip efficiency (RTE), exergy efficiency (ηEx), thermal efficiency (ηTE), and energy density (ρE) were defined to show the system performance. Parametric analysis was carried out to examine the effects of some key parameters on system performance and the genetic algorithm was adopted for system optimization. The calculated results show that, for the novel EES under the basic working condition, its RTE is 41.4%, ηTE is 59.7%, ηEx is 45.4%, and ρE is 15 kWh m−3. The value of ρE increases with the increasing pump outlet pressure for a fixed value of pressure ratio, and the changes of RTE, ηTE, and the total exergy destruction of the system (ED,total) with pump outlet pressure are complicated for different values of pressure ratio. When both pressure ratio and pump outlet pressure are high, the values of RTE and ρE can be maximized whereas the value of ED,total can be minimized. Besides, no matter how pump outlet pressure and pressure ratio change, the exergy destruction of the system mainly come from compressors and regenerators, which accounts for about 50% of the total exergy destruction.

Progress and Evaluation of Compressed Carbon Dioxide Energy Storage Systems: A Review

“…Because carbon dioxide is a greenhouse gas that has a significant impact on global temperature change, and the process of capturing and collecting carbon dioxide is complex, the CCES system uses closed technology, which means there is no material exchange with the outside world during the entire energy storage process, only energy exchange. Figure 3 depicts the CCES device in action, the working principle of the system is as follows: when storing energy, the carbon dioxide is compressed by surplus electric energy, stored after heat exchange by the heat storage device, and the highpressure carbon dioxide is stored in the storage tank, and the compressed heat is stored in the heat storage device; during energy release, the high-pressure carbon dioxide is heated by heat exchange, drives the expander to do work, and outputs electric energy, and the carbon dioxide after the work is cooled to the initial state to store [46,47]. To maintain the liquid or supercritical state of carbon dioxide working fluid in the gas storage chamber in the existing CCES system, the CCES system must use a specially manufactured gas storage tank to ensure the temperature and pressure of the gas storage chamber [48].…”

Thermodynamic analysis of a compressed carbon dioxide energy storage system with a big flexible holder

“…They employed flexible underwater energy bags in order to maintain isobaric storage. Zhang et al [4] proposed a novel liquid carbon dioxide energy storage (LCES) system. They utilized low-temperature thermal energy storage to improve utilization efficiency of compression waste heat.…”

An innovative s olar‐powered natural g as‐based compressed air energy storage system integrated with a liquefied air power cycle

“…Several working fluids are suitable for this purpose [19]. As an example of the compressed gas energy storage, the feasibility of compressed carbon dioxide energy storage (CCES) integrated with low-temperature thermal energy storage has been studied in the literature [20] in which the results show the feasibility of the cycle to be used in cogeneration systems. For the assessment of compressed air energy storage systems, the heat transfer mechanism and heat losses from the storage tank or cavern should be considered.…”