Energetic and economic analysis of trans-critical CO2 booster system for refrigeration in warm climatic condition

Purohit, Nilesh; Gupta, D.; Dasgupta, Mani Sankar

doi:10.1016/j.ijrefrig.2017.04.023

Cited by 44 publications

(23 citation statements)

References 27 publications

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“…Some of these improvements are: parallel compression [17] to reduce the mass flow rate of the medium temperature compressor (MTC), mechanical subcooling [18,19] to increase the specific cooling capacity in evaporators, systems with ejectors and parallel compression [20,21] to reduce exergy losses in the expansion processes and the MTC mass flow rate, and overfeed evaporators [22,23] to achieve higher evaporation temperature. In addition, the heating and air conditioning integration in the booster architecture is possible and it is an efficient solution to reduce annual energy consumption as analysed by Karampour et al [15] and Hafner et al [24].…”

Section: Introductionmentioning

confidence: 99%

Energy Evaluation of Multiple Stage Commercial Refrigeration Architectures Adapted to F-Gas Regulation

et al. 2018

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This work analyses different refrigeration architectures for commercial refrigeration providing service to medium and low temperature simultaneously: HFC/R744 cascade, R744 transcritical booster, R744 transcritical booster with parallel compression, R744 transcritical booster with gas ejectors, R513A cascade/R744 subcritical booster, and R513A cascade/R744 subcritical booster with parallel compression. The models were developed using compressor manufacturers’ data and real restrictions of each system component. Limitations and operating range of each component and architecture were analysed for environment temperatures from 0 to 40 °C considering thermal loads and environment temperature profiles for warm climates. For booster systems, cascade with subcritical booster with parallel compression provide highest coefficient of performance (COP) for temperatures below 12 °C and above 30 °C with COP increases compared basic booster up to 60.6%, whereas for transcritical boosters, architecture with gas ejectors obtains the highest COP with COP increases compared to the basic booster up to 29.5%. In annual energy terms, differences among improved booster systems are below 8% in the locations analysed. In Total Equivalent Warming Impact (TEWI) terms, booster architectures get the lowest values with small differences between improved boosters.

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Section: Introductionmentioning

confidence: 99%

Energy Evaluation of Multiple Stage Commercial Refrigeration Architectures Adapted to F-Gas Regulation

et al. 2018

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“…According to the ambient temperature, the system can be divided into four stages, 27 which is given in Table 2: the condenser temperature and approach temperature is fixed when the outdoor temperature is below 4°C; when the temperature is between 4°C and 17°C, both auxiliary compressor and bypass valve are closed, the system is running at sub‐critical mode; when the temperature is higher than 17°C but lower than 27°C, the fluid in the system is in transition state and trans‐critical cycle; the system completely enters the trans‐critical mode while the range of the systems' ambient temperature is between 27°C and 47°C, and the gas cooler pressure should be optimized through curve fitting.…”

Section: System Descriptionsmentioning

confidence: 99%

Thermodynamic performance evaluation of the CO ₂ parallel compression supermarket refrigeration system with a subcooler

et al. 2020

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Summary Commercial refrigeration systems in supermarkets are intensive users of energy and CO2 is recognized as the most promising refrigerant such systems. The CO2 parallel compression system has been considered in medium‐ and low‐temperature supermarket refrigeration systems, with auxiliary compressors to enhance system performance. This study is intended to investigate the effects of adding a subcooler in a CO2 trans‐critical supermarket refrigeration system with parallel compression (SPR system). Mathematical models based on mass and energy conservation are built. Optimization is performed for the gas cooler pressure and the receiver pressure for maximizing the coefficient of performance (COP). The performance of the parallel compression system with a subcooler is analyzed and compared to a baseline parallel compression system in different cities of China. A 6.8% average promotion at least in seasonal energy efficiency ratio (SEER) is predicted, and the energy consumption of the whole system decreases 7.1% totally in Haikou. Gas cooler, taking up 63.3% of the total exergy destruction rate, is the key component to increase efficiency through exergy analysis.

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“…It was obvious that the Ref system leads to higher COP compared to the ACH-SC system for all the cases. The reason for this result is based on the definition of COP according to Equation (9). This equation evaluates the work and the heat input in the same way by simply adding them in the denominator of the COP.…”

Section: Absorption Chiller Subcooling System Performancementioning

confidence: 99%

“…This fact is the key parameter that leads to a decreased coefficient of performance (COP) and, consequently, to higher electricity consumption. In this direction, a lot of researchers have studied the use of alternative methods for enhancing the COP of the refrigeration cycle with CO 2 [9].…”

Section: Introductionmentioning

confidence: 99%

CO2 Transcritical Refrigeration Cycle with Dedicated Subcooling: Mechanical Compression vs. Absorption Chiller

Bellos

Tzivanidis

2019

Applied Sciences

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The objective of this paper is the comparison of two dedicated subcooling methods, after the gas cooler, in a CO2 transcritical refrigeration system. The use of vapor compression refrigeration with R134a for subcooling is the first method, and the second is the use of an absorption chiller that operates with a LiBr-H2O working pair. The examined systems are compared energetically and exegetically with the reference transcritical CO2 refrigeration cycle without subcooling. The analysis is conducted for different operating scenarios and in every case, the system is optimized by selecting the proper temperature and pressure levels. The analysis is performed with a developed and validated model in Engineering Equation Solver. According to the final results, the use of the absorption chiller is able to decrease the system electricity consumption by about 54% compared to the simple transcritical cycle, while the decrease with the mechanical subcooling is 41%. Both systems with dedicated subcooling are found to have an important increase in the system exergy performance compared to the simple transcritical cycle. However, the system with the mechanical subcooling is found to be the best choice exegetically, with a small difference from the system with the absorption chiller.

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Energetic and economic analysis of trans-critical CO2 booster system for refrigeration in warm climatic condition

Cited by 44 publications

References 27 publications

Energy Evaluation of Multiple Stage Commercial Refrigeration Architectures Adapted to F-Gas Regulation

Energy Evaluation of Multiple Stage Commercial Refrigeration Architectures Adapted to F-Gas Regulation

Thermodynamic performance evaluation of the CO ₂ parallel compression supermarket refrigeration system with a subcooler

CO2 Transcritical Refrigeration Cycle with Dedicated Subcooling: Mechanical Compression vs. Absorption Chiller

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Energetic and economic analysis of trans-critical CO2 booster system for refrigeration in warm climatic condition

Cited by 44 publications

References 27 publications

Energy Evaluation of Multiple Stage Commercial Refrigeration Architectures Adapted to F-Gas Regulation

Energy Evaluation of Multiple Stage Commercial Refrigeration Architectures Adapted to F-Gas Regulation

Thermodynamic performance evaluation of the CO 2 parallel compression supermarket refrigeration system with a subcooler

CO2 Transcritical Refrigeration Cycle with Dedicated Subcooling: Mechanical Compression vs. Absorption Chiller

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Thermodynamic performance evaluation of the CO ₂ parallel compression supermarket refrigeration system with a subcooler