Conceptual Design and Analysis of a Novel CO₂ Hydrate-Based Refrigeration System with Cold Energy Storage

Abstract

CO 2 hydrate can be used as an alternate cooling substance in air-conditioning systems to minimize the use of traditional refrigerants, such as HFCs and HCFCs. A novel CO 2 hydrate-based refrigeration system with a function of cold energy storage was designed and investigated, using tetrahydrofuran (THF) as the thermodynamic promoter. Coefficient of performance (COP) of this system was calculated based on the simulation results. Effects of various operation parameters were also studied closely. The cold storage operation was then designed to investigate the energy storage ability of the current system. Results show that the system COP is 6.8, which is the major strength of this novel system. Because of the energy intensive process of CO 2 compression, the work imposed on elevating the gas pressure was considerable. A search for more appropriate additives or alternate guest substances should be conducted. In addition, compressor efficiency and pump efficiency are both critical for improving the energy efficiency. Enhanced refrigeration performance can also be realized at higher hydrate mass fraction. In addition, two different cold energy storage operation strategies were obtained. This research is of great significance to the in-depth development of hydrate-based refrigeration and cold energy storage system. The proposed system might contribute to minimizing the use of conventional coolants and realizing peak load shifting in the near future.

Development and Continuous Operation of a Bench‐Scale System for the Production of O3 + O2 + CO2 Hydrates

“…The application of clathrate hydrate (hydrate) in gas separation and molecular storage techniques has already been proposed and investigated [11][12][13][14][15][16][17]. As a molecular storage technology, hydrates containing O 3 have been used [18][19][20][21][22][23][24][25].…”

Assessment of Low Global Warming Potential Refrigerants for Drop-In Replacement by Connecting their Molecular Features to Their Performance

“…Even though environmentally friendly refrigeration and cooling technologies are being developed such as absorption refrigeration, − adsorption refrigeration, and other novel systems, the cooling industry is still heavily reliant on the more efficient vapor compression refrigeration cycles (VCRCs) with fluorinated compounds as working fluids. As such, in lieu of the current targets of environmental legislations, the search for alternative refrigerants replacing HFCs for today’s market is solely dictated by eco-friendly properties such as zero ODP, low GWP, and moderate safety-related properties (i.e., flammability, and toxicity), examining a wide array of substances both natural and synthetic as potential replacements to the currently used third generation refrigerants.…”

Improved Operation of Continuous Ozone Hydrate Production

“…Molecular storage technologies of clathrate hydrate (hydrate) would be useful applications for the storage of chemically unstable compounds 10–16. Hydrates are crystalline solids consisting of hydrogen‐bonded water molecules which form cages, and guest molecules are encapsulated in the cages.…”