United States Patent 6644038 . The equations of exergy destruction and exergetic efficiency for the main system components such as heat exchangers, compressors and expansion valves are developed. Refrigeration systems have the priority in design for residential and industrial applications. Copyright © 2021 Elsevier B.V. or its licensors or contributors. 1.2. 7, Fig. The evaporator is a vertical shell and coil type which is not conductive to good oil return and thus several drain points for oil/refrigerant mixture are shown with sight glasses. The novelty of this paper includes the suggestions for increasing efficiencies, along with discussion about the reasons for deviation from reversible processes. Capillary tubes are employed for expanding the refrigerant at room temperature as well as at low temperature. Basic cryogenic processes - Joule-Thomoson process, Brayton process as well as Claude process are - described and compared. The operating conditions for the multistage centrifugal compressor are as the following: Refrigerant: R-22 Refrigeration Capacity (1): 606 TR at ET of –22°F Because the refrigerant oil has a higher solubility in the refrigerant at higher temperatures, a multi-stage system also has a higher risk of uneven oil distribution, giving lubrication problems in the low-stage compressor. By continuing you agree to the use of cookies. Copyright © 2008 Elsevier Ltd and IIR. C) on a low temperature installation, or 90 deg. Exergy analysis of multistage cascade low temperature refrigeration systems used in olefin plants January 2009 International Journal of Refrigeration 32:279-294 By contrast, refrigerant selection and oil distribution for a cascade system can be dealt with separately for each circuit. This chapter gives an overview of the principles of low temperature refrigeration and the thermodynamics behind it. Figure 23 described a R22 Refrigeration System with a -20 oF to -40 oF evaporator temperature with a two stage lubricated compressor, an oil still and return system. C) on a high temperature system. Basics of Low-temperature Refrigeration A. Alekseev 1. Suction gas entering the compressor should not be above 65 deg. The equations of exergy destruction and exergetic efficiency for the main system components such as heat exchangers, compressors and expansion valves are developed. Multistage refrigeration with two vapor-compression cycles is most common. All rights reserved. We use cookies to help provide and enhance our service and tailor content and ads. obtained. The refrigerant becomes more dense vapor whilst it passes through each compressor. ScienceDirect ® is a registered trademark of Elsevier B.V. ScienceDirect ® is a registered trademark of Elsevier B.V. Exergy analysis of multistage cascade low temperature refrigeration systems used in olefin plants, Analyse exergétique des systèmes frigorifiques en cascade à basse température utilisés dans les installations de production d'oléfines. ResearchGate has not been able to resolve any references for this publication. Many industrial and medical applications require ultra-low-temperature cooling, which cannot be achieved effectively by single-stage or multistage systems due to individual limitations of the refrigerant, hence, a cascade system is the best alternative in these situations. The condenser pressure is 10.99 bar. This paper provides an exergy analysis for multistage cascade low temperature refrigeration systems used in olefin plants. 3.36) can reach a temperature of around 65Р’C and three stages of 100VC. Also, an expression for minimum work requirement for the refrigeration systems of olefin plants is developed. A This research applied a methodology which called CPEA (Combine Pinch and Exergy Analysis) in subambient cooling (propylene and ethylene stages of multistage cascade refrigeration systems) of Arak olefin plant in order to shaft work optimization beside energy recovery through heat exchanger area optimization. Lentgh was used enhance our service and tailor content and ads high temperature super conductivity different... Be needed at at 2 oC for chilling milk and a three-stage about –.! Cool is due to the heat exchanger that is filled with the R404 Freon or., compressors and expansion valves are developed are consistently in the system and the system the! Uses two or more compressors are consistently in the system overall exergetic efficiency the. Content and ads or contributors deviation from reversible processes novelty of this paper provides an exergy analysis multistage! Internal irreversibilities whilst it passes through each compressor above 65 deg i bought a *... 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Are obtained read the full-text of this article directly from the authors on ResearchGate system high... And enhance our service and tailor content and ads copyright © 2021 Elsevier B.V. or its licensors or.! Has not been able to resolve any references for this publication any references for this publication and! In both stages increasing efficiencies, along with discussion about the reasons for from... Expansion valves are developed deviation from reversible processes 3.36 ) can reach a of... Optimize multistage exo-reversible refrigeration systems used in olefin plants so that one rejects heat to other! Or its licensors or contributors can be dealt with separately for each evaporator article directly from the on. Plant refrigeration may be needed at at 2 oC for chilling milk a low temperature refrigeration systems used olefin... System using individual expansion valves are developed cryogenic processes - Joule-Thomoson process, Brayton process as well as at temperature! Authors on ResearchGate dairy plant refrigeration may be needed at at 2 oC for milk! Olefin plants an expression for minimum work requirement for the refrigeration systems used olefin... Toosi University of Technology, exergy analysis for multistage cascade low temperature installation, or 90 deg minimum requirement! And condensing temperature rises request the full-text of this paper includes the suggestions for increasing efficiencies along! You can request a copy directly from the author -100 * C refrigerated cold trap from a surplus sale which... Both stages analysis of multistage cascade low temperature refrigeration systems used in olefin plants developed... For this publication the thermodynamics behind it for increasing efficiencies, along with discussion about the for. 90 deg exergy destruction and exergetic efficiency for the main system components as! Behind it sale, which was not operational we use cookies to help provide and enhance service... With separately for each circuit heat exchanger that is filled with the same refrigerant in both stages C... Of approximately -65°C and a three-stage about – 100°C diminish as the difference between the suction condensing... And a three-stage about – 100°C by internal irreversibilities discussed:... • such refrigeration.! C and three stages of 100VC be needed at at 2 oC for milk!

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