Experimental performance assessment of a vacuum cooling system through exergy analysis method

Energy saving and environmental protection are topics of growing interest. In the light of these aspects alternative refrigeration principles become increasingly important. Shape memory alloys (SMA), especially NiTi alloys, generate a large amount of latent heat during solid state phase transformations, which can lead to a significant cooling effect in the material. These materials do not only provide the potential for an energy-efficient cooling process, they also minimize the impact on the environment by reducing the need for conventional ozone-depleting refrigerants. Our paper, presenting first results obtained in a project within the DFG Priority Program SPP 1599 “Ferroic Cooling”, focuses on the thermodynamic analysis of a NiTi-based cooling system. We first introduce a suitable cooling process and subsequently illustrate the underlying mechanisms of the process in comparison with the conventional compression refrigeration system. We further introduce a graphical solution to calculate the energy efficiency ratio of the system. This thermodynamic analysis method shows the necessary work input and the heat absorption of the SMA in stress/strain- or temperature/entropy-diagrams, respectively. The results of the calculations underline the high potential of this solid-state cooling methodology.

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Optimization of an Automotive Cooling System Based on Exergy Analysis

10.4271/2004-01-3541 ◽

2004 ◽

Author(s):

Haipeng Li ◽

Richard S. Figliola

Keyword(s):

Exergy Analysis ◽

Cooling System

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Study on Energy Consumption Analysis Method of Distributed Cryogenic Separation System

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.732-733.52 ◽

2013 ◽

Vol 732-733 ◽

pp. 52-56

Author(s):

Zhi Guo Wang ◽

Lei Zhang ◽

Chai Ling Yin

Keyword(s):

Energy Use ◽

Exergy Analysis ◽

Waste Heat ◽

Engineering Practice ◽

Analysis Method ◽

Analysis Model ◽

Two Stage ◽

Separation Plant ◽

Flow Energy ◽

Saving Effect

Cryogenic separation method is the main method to recycle NGL (Natural Gas Liquid). Oilfield two-stage expansion NGL cryogenic separation plant is a complex system composed of varieties of material flow, energy flow and equipments, is a typical distributed energy use system composed of three parts, energy supply, energy use and waste heat recovery. In this paper, according to the process characteristics of two-stage expansion cryogenic separation plant, three-box analysis method was used, the system was compartmentalized into six subsystems, represented the exergy analysis model of system—unit—equipment, given the specific analysis process and the assessment rules for the NGL system. Using the practical operational data, the writers conduct the exergy analysis on the operational working condition of Daqing oilfield NGL system. Based on the calculation results, this paper raises some proposals to improve the operational efficiency, and achieved a good energy saving effect in engineering practice.

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