Thermodynamic analyses and comparison of ammonia-, propane-and isobutane-based vapour compression refrigeration cycles are presented in this article using constant area mixing ejector as an expansion device. Optimization of ejector geometric parameter based on the maximum cooling COP and performance
Optimal synthesis of refrigeration cycles and selection of refrigerants
β Scribed by Shankar Vaidyaraman; Costas D. Maranas
- Publisher
- American Institute of Chemical Engineers
- Year
- 1999
- Tongue
- English
- Weight
- 273 KB
- Volume
- 45
- Category
- Article
- ISSN
- 0001-1541
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β¦ Synopsis
Abstract
The optimal synthesis of the refrigeration configuration and the selection of the best refrigerants that satisfy a set of process cooling duties at different temperatures is addressed. This approach simultaneously selects refrigerants and synthesizes refrigeration structures by minimizing a weighted sum of investment and operating costs. A superstructure representation considers the majority of refrigeration cycle features encountered in real complex multistage refrigeration cycles such as economizers, multiple refrigerants, and heat integration. A novel theoretical treatment of modeling representations and algorithmic improvements is introduced. Results, for example, involving multiple refrigerants, cooling loads, and heat sinks are obtained. Complex, nonintuitive topologies typically emerge as the optimal refrigeration configurations that are better than those obtained when refrigeration synthesis is performed after refrigerant selection.
π SIMILAR VOLUMES
Thermoeconomic optimization of simple refrigerators is formulated and applied to a speci"c case. Condenser and evaporator areas and compressor e$ciency are selected as the independent design variables of the system components. Exergy analysis is carried out to "nd local and total irreversibilities.
Electrochemical processes may be used to form thermodynamic cycles in a variety of manners. In this paper, an electrochemical cell and fuel cell are combined to form a refrigeration cycle. Water is chosen as an example for the analysis in order to show ideal performance characteristics of such a cyc
Ejector refrigeration systems can use low grade thermal energy, at temperatures as low as 60Β°C, to provide space cooling. Since this waste energy is widely available and the cost of its supply is negligible in many cases, cooling costs can be lower than conventional systems, which makes the method v