Energy saving potential in freezing applications by applying cold thermal energy storage with solid carbon dioxide

We evaluated the viability of integrating a cold thermal energy storage (CTES) into an all-electric ship to mitigate the aftermath of thermal cycling and cooling loss by providing additional thermal damping. 1D dynamic CTES and counterflow heat exchanger (HX) models were developed and solved in dimensionless forms to assess the proposed cooling configuration based on the following: (1) the impact of chiller HX (evaporator) design on thermal damping without the CTES; and (2) the effects of adding a CTES next to the chiller as a complementary thermal damper (HX + CTES). Numerical results demonstrate the higher sensitivity of the damping effect to the total number of transfer units (N) than the HX mass, and the required N to achieve the same damping effect reduces nonlinearly with increasing HX mass. Furthermore, the HX + CTES outperforms the HX of the same total mass at higher N when the effect of heat transfer overcomes that of thermal inertia, and its merit becomes more evident when we compare the operation of these two configurations. This work thus reveals the potential of HX + CTES as a practical approach for improving the overall ship cooling reliability.

A techno-economic assessment on the adoption of latent heat thermal energy storage systems for district cooling optimal dispatch & operations

Cold thermal energy storage (CTES) based on phase change materials (PCMs) has shown great promise in numerous energy-related applications. Due to its high energy storage density, CTES is able to balance the existing energy supply and demand imbalance. Given the rapidly growing demand for cold energy, the storage of hot and cold energy is emerging as a particularly attractive option. The main purpose of this study is to provide a comprehensive overview of the current research progress on the utilisation of PCMs in CTES. The greatest difficulties associated with using PCMs for CTES are also examined in this overview. In this regard, a critical evaluation of experimental and numerical studies of the heat transfer properties of various fundamental fluids using PCMs is conducted. Specifically, several aspects that affect the thermal conductivity of PCMs are investigated. These factors include nanoparticle-rich PCM, a form of encapsulated PCM, solids volume percentage, and particle size. Discussions focus on observations and conclusions are drawn from conducted studies on PCMs used in CTES. Based on the findings of this study, a set of plausible recommendations are made for future research initiatives.

Review on operation control of cold thermal energy storage in cooling systems

Amine infused hydrogel-based CO2 gas storage technology for CO2 hydrate-based cold thermal energy storage

A theoretical and experimental study of a TBAB salt hydrate based cold thermal energy storage in an air conditioning system

Thermal energy storage based on cold phase change materials: Charge phase assessment

Review on phase change materials for cold thermal energy storage applications

Cold thermal energy storage with lauryl alcohol and cetyl alcohol eutectic mixture: Thermophysical studies and experimental investigation

District cooling (DC) has emerged as a highly relevant pathway for reducing carbon emissions and enhancing energy efficiency. However, DC systems face operational challenges such as load variation and fluctuating electricity prices. Integrating energy storage technologies with DC systems offers a promising solution. Although several studies have been reported in literature, the potential of thermal energy storage (TES) for DC applications remains underexplored. This study aims to assess the feasibility of DC systems integrated with energy storage technologies, considering multiple parameters from technical, economic, and environmental domain. Data collection was conducted in the context of a university campus, depending on system alternatives and boundary conditions. Three system configurations (SC) were formulated to assess the impact of integrating energy storage: a typical DC plant (base case, BC), a typical DC system coupled with cold TES (SC1), and a DC system coupled with cold TES and electrical storage (SC2). At the system level, the observed energy efficiency ratios (EER) were 4.79 (BC), 4.78 (SC1), and 4.67 (SC2). This slight decline is attributed to the increased electricity consumption when energy storage is integrated. The economic assessment showed discounted payback periods of 7 years (BC), 5 years (SC1), and 6 years (SC2). While hybrid energy storage (thermal and electrical) reduced operational expenses, it increased investment and maintenance costs. Significant emission reductions were not achieved, as electricity remained the primary energy source in all configurations. The lowest and highest specific cooling emissions were found for BS (33.6 kgCO2/MWh) and SC2 (37.1 kgCO2/MWh), respectively. These findings are expected to strengthen the wider adoption of innovative DC solutions in the cities of Northern Europe.

Role of metal foam on ice storage performance for a cold thermal energy storage (CTES) system

Natural refrigerants such as ammonia, hydrocarbons and CO2 are becoming increasingly popular due to favorable thermo-physical properties, low environmental impact and low cost. Industrial refrigeration systems are often installed in applications where the difference in peak and average cooling load is substantial. Cold thermal energy storage (CTES) integrated into the system enables shifting of the load from peak hours to off-peak hours, which enables design of the system capacity closer to the average load rather than the peak load. This paper describes the design and development of a CTES unit and associated experimental test rig. The CTES unit consists of a stack of heat exchanger plates contained in a steel tank, initially filled with water as the phase change material (PCM). CO2 circulates within the plates to freeze and melt the water during charge and discharge cycles, respectively.

This paper presents a thorough review on the recent developments and latest research studies on cold thermal energy storage (CTES) using phase change materials (PCM) applied to refrigeration systems. The presented study includes a classification of the different types of PCMs applied for air conditioning (AC) systems (20 °C) to low-temperature freezing of food (−60 °C). An overview of the influencing thermophysical properties of PCMs, as well as their respective characterisation methods, are presented. The current available PCMs on the market in the temperature range 10 °C to −65 °C are listed. Finally, research on CTES using PCMs in refrigeration systems are reviewed and grouped into applications for food transport and packaging, commercial refrigeration and various other refrigeration systems. The findings show that using ice/water as PCM for AC applications is the most commonly studied system, due to widespread use of these systems, expected growth in the future and low cost of using water as the PCM. Over the last ten years the published research integrating CTES in different parts of the food cold chain, using water-salt solutions and paraffin PCM in both active and passive methods, has increased. Suggestions for the integration of CTES in supermarkets and industrial applications are also emerging. The technology has received increased interest from the scientific community the last five years, due to the benefits of achieving peak shaving of the refrigeration demand, exploiting low-cost electricity hours and offering backup refrigeration in case of blackouts.

Developing a cold thermal energy storage (CTES) technology is one of the most effective methods to solve energy shortage and environmental pollution all over the world. The current study deals with the modelling and simulation of a cold thermal energy storage tank consisting of an polyvinyl chloride pipe (PVC) heat exchanger partially filled with a phase change material (PCM). Water, as the heat transfer fluid (HTF), flows through the inner tubes and the outer one while propylene glycol as the phase change material fills. This paper focuses on studying the effect of the velocity characteristics on the heat transfer efficiency of polyvinyl chloride pipe (PVC) heat exchanger in cold thermal energy storage system by the numerical simulation. In this paper, the detail of heat transfer performance within the heat exchanger is numerically solved using computational fluid dynamics (CFD), for various velocity as well as different heat transfer for optimal design. Several results of changes in the temperature field at the outlet of the cold thermal energy storage tank are presented when the inlet water velocity changes from 1 m/s to 1.4 m/s. The results indicate that low input water velocity will provide better heat exchange efficiency. However, it is required to make sure that the flow inside the heat exchanger is the turbulent flow because the study uses turbulent flow modules.

A comprehensive review on sub-zero temperature cold thermal energy storage materials, technologies, and applications: State of the art and recent developments