Search results

Filters

  • Journals
  • Authors
  • Keywords
  • Date
  • Type

Search results

Number of results: 2
items per page: 25 50 75
Sort by:
Download PDF Download RIS Download Bibtex

Abstract

The objective of this work is to present an energy analysis of different absorption refrigerating systems operating with diverse refrigerants. Also is applied the method of experimental design to optimize configurations proposed by the absorption pairs used and the operating conditions. Both acceptable coefficient of performance and low operating generator temperature are scrutinised. Therefore, a computer program is developed. An investigation of the thermodynamic properties is presented. Results show the coefficient of performance evolution versus respectively the evaporator temperature, temperature of condensation and generator temperature. A particular interest is devoted to the intermediate pressure effect on the performance of different systems. In order to better converge in the selection of the configuration and the refrigerant, which can ensure a high coefficient of performance associated to relatively low operating generator temperature the plan of experiments has been developed, taking in account all parameters influencing the system performance and the function of operating temperature. Results show that the refrigerating machine containing a compressor between the evaporator and the absorber has a coefficient of performance quite acceptable and that it can work at low generator temperature for about 60 ◦C and using the NH3/LiNO3 as refrigerant.

Go to article

Authors and Affiliations

Ridha Ben Iffa
Lakdar Kairouani
Nahla Bouaziz
Download PDF Download RIS Download Bibtex

Abstract

The geometry and operating parameters have an important influence on the performance of ejectors. The improvement of the refrigeration cycle performance and the design of the ejectors for the compression energy recovery requires a detailed analysis of the internal ejector working characteristics and geometry. To this aim, an experimental investigation of an ejector refrigeration system is conducted to determine the effect of the most important ejector dimensions on ejector working characteristics and system performance. Different dimensions of ejector components are tested. The influence of the ejector’s geometrical parameters on the system performance was analysed. The experiments with respect to the variation of ejector geometry such as the motive nozzle throat diameter, the mixing chamber diameter and the distance between the motive nozzle and diffuser were carried out. There exist optimum design parameters in each test. The experimental results show that the performance (entrainment ratio and a compression ratio of the ejector) increases significantly with the position between the primary nozzle and the mixing chamber. A maximum entrainment ratio of 57.3% and a compression ratio of 1.26 were recorded for the different parameters studied. The results obtained are consistent with experimental results found in the literature.
Go to article

Bibliography

[1] Elbel S., Hrnjak P.: Experimental validation of a prototype ejector designed to reduce throttling losses encountered in transcritical R744 system operation. Int. J. Refrig. 31(2008), 3, 411–422.
[2] Liu J.P., Chen J.P., Chen Z.J.: Thermodynamic analysis on transcritical R744 vapor compression/ejection hybrid refrigeration cycle. In: Prelim. Proc. 5th IIR Gustav Lorentzen Conf. on Natural Working Fluids, Guangzhou 2002, 184–188.
[3] Jeong J., Saito K., Kawai S., Yoshikawa C., Hattori K.: Efficiency enhancement of vapor compression refrigerator using natural working fluids with two-phase flow ejector. In: Proc. 6th IIR-Gustav Lorentzen Conf. on Natural Working Fluids at Glasgow 2004, CD-ROM.
[4] Jian-qiang Deng, Pei-xue Jiang, Tao Lu, Wei Lu: Particular characteristics of transcritical CO2 refrigeration cycle with an ejector. Appl. Therm. Eng. 27(2007), 381–388.
[5] Da Qing Li, Groll E.A.: Transcritical CO2 refrigeration cycle with ejectorexpansion device. Int. J. Refrig. 28(2005), 5, 766–773.
[6] Ksayer E.B., Clodic D.: Enhancement of CO2 refrigeration cycle using an ejector: 1D analysis. In: Proc. Int. Refrigeration and Air Conditioning Conf., Purdue 2026, Purdue Univ. R058.2006.
[7] Bartosiewicz Y., Aidoun Z., Mercadier Y.: Numerical assessment of ejector operation for refrigeration applications based on CFD. Appl. Therm. Eng. 26(2006), 5-6, 604–612.
[8] Petrenko V.O., Huang B.J., Ierin V.O.: Design-theoretical study of cascade CO2 sub-critical mechanical compression/butane ejector cooling cycle. Int. J. Refrig. 34(2011), 7, 1649–1656.
[9] Martel S.: Étude numérique d’un écoulement diphasique critique dans un convergent- divergent. PhD thesis, Université de Sherbrooke, Sherbrooke 2013 (in French).
[10] Marynowski T.: Étude expérimentale et numérique d’écoulements supersoniques en éjecteur avec et sans condensation. PhD thesis, Université de Sherbrooke, Sherbrooke 2007 (in French).
[11] Scott D., Aidoun Z., Ouzzane M.: An experimental investigation of an ejector for validating numerical simulations. Int. J. Refrig. 34(2011), 7, 1717–1723.
[12] Chen H., Zhu J., Ge J., Lu W., Zheng L.: A cylindrical mixing chamber ejector analysis model to predict the optimal nozzle exit position. Energy 208(2020), 118302.
[13] Mondal S., De D.: Performance assessment of a low-grade heat driven dual ejector vapor compression refrigeration cycle. Appl. Therm. Eng. 179(2020), 115782.
[14] Ringstad K.E., Allouche Y., Gullo P., Banasiak K., Hafner A.: A detailed review on CO2 two-phase ejector flow modeling. Thermal Sci. Eng. Progress 20(2020), 100647.
[15] Yu B., Yang J., Wang D., Shi J., Chen J.: An updated review of recent advances on modified technologies in transcritical CO2 refrigeration cycle. Energy 189(2019), 116147.
[16] Chen W., Liu M., Chong D., Yan J., Little A.B., Bartosiewicz Y.A.: 1D model to predict ejector performance at critical and sub-critical operational regimes. Int. J. Refrig. 36(2013), 6, 1750–1761.
[17] Banasiak K., Hafner A., Andresen T.: Experimental and numerical investigation of the influence of the two-phase ejector geometry on the performance of the R744 heat pump. Int. J. Refrig. 35(2012), 6, 1617–1625.
[18] Domanski P.A.: Theoretical Evaluation of the Vapor Compression Cycle With a Liquid-Line/Suction-Line Heat Exchanger, Economizer, and Ejector. National Institute of Standards and Technology, NISTIR-5606, 1995.
[19] Elbel S.W., Hrnjak P.S.: Effect of internal heat exchanger on performance of transcritical CO2 systems with ejector. In: Proc. 10th Int. Refrigeration and Air Conditioning Conf. Purdue 2004, R166, West Lafayette 2004.
[20] Kornhauser A.A.: The use of an ejector as a refrigerant expander. In: Proc. USNC/IIR-Purdue Refrigeration Conf., Purdue Univ.,West Lafayette 1990, 10–19.
[21] Lawrence N., Elbel S.: Experimental and analytical investigation of automotive ejector air-conditioning cycles using low-pressure refrigerants. In: Proc. Int. Refrigeration and Air Conditioning Conf., Purdue, July 16-19, 2012, 1169, 1–10.
[22] Liu F., Li Y., Groll E.A.: Performance enhancement of CO2 air conditioner with a controllable ejector. Int. J. Refrig. 35(2012), 6, 1604–1616.
[23] Domanski P.A.: Minimizing throttling losses in the refrigeration cycle. In: Proc. 19th Int. Congress of Refrigeration, Hague 1995, 766–773.
[24] Varga S., Oliveira A., Diaconu B.: Influence of geometrical factors on steam ejector performance – A numerical assessment. Int. J. Refrig. 32(2009), 7, 1694– 1701.
[25] Sarkar J.: Optimization of ejector-expansion transcritical CO2 heat pump cycle. Energy 33(2008), 9, 1399–1406.
[26] Elbel S.: Historical and present developments of ejector refrigeration systems with emphasis on transcritical carbon dioxide air-conditioning applications. Int. J. Refrig. 34(2011), 7, 1545–1561.
[27] Lee J.S., Kim M.S., Kim M.S.: Experimental study on the improvement of CO2 air conditioning system performance using an ejector. Int. J. Refrig. 34(2011), 7, 1614–1625.
[28] Lucas C., Koehler J.: Experimental investigation of the COP improvement of a refrigeration cycle by use of an ejector. Int. J. Refrig. 35(2012), 6, 1595–1603.
[29] Nakagawa M., Marasigan A.R., Matsukawa T., Kurashina A.: Experimental investigation on the effect of mixing length on the performance of two-phase ejector for CO2 refrigerationcycle with and without heat exchanger. Int. J. Refrig. 34(2011), 7, 1604–1613.
[30] Nakagawa M., Marasigan A.R., Matsukawa T.: Experimental analysis on the effect of internal heat exchanger in transcritical CO2 refrigeration cycle with twophase ejector. Int. J. Refrig. 34(2011), 7, 1577–1586.
[31] Nakagawa M., Marasigan A.R., Matsukawa T.: Experimental analysis of two phase ejector system with varying mixing cross-sectional area using natural refrigerant CO2. Int. J. Air-Cond. Refrig. 18(2010), 4, 297–307.
[32] Liu F., Groll E.A., Li D.: Investigation on performance of variable geometry ejectors for CO2 refrigeration cycles. Energy 45(2012), 1, 829–839.
[33] Liu F., Groll E.A.: Analysis of a two-phase flow ejector for transcritical CO2 cycle. Int. Refrig. Air Cond. Conf., Purdue, July 14–17, 2008, 924.
[34] Liu F., Groll E.A.: Study of ejector efficiencies in refrigeration cycles. Appl. Therm. Eng. 52(2013), 2, 360–370.
[35] Lawrence N., Elbel S.: Experimental investigation on the effect of evaporator design and application of work recovery on the performance of two-phase ejector liquid recirculation cycles with R410A. Appl. Therm. Eng. 100(2016), 398–411.
[36] Van Nguyen V., Varga S., Soares J., Dvorak V., Oliveira A.C.: Applying a variable geometry ejector in a solar ejector refrigeration system. Int. J. Refrig. 113(2020), 187–195.
[37] Pereira P.R., Varga S., Soares J., Oliveira A.C., Lopes A.M., de Almeida F.G., Carneiro J.F.: Experimental results with a variable geometry ejector using R600a as working fluid. Int. J. Refrig. 46(2014), 77–85.
[38] Liu F., Groll E.: A preliminary study of the performance enhancement of a dualmode heat pump using an ejector. In: Proc. 25th IIR Int. Cong. of Refrigeration, ICR2015, Yokohama, Aug. 16-22, 2015, 16–22.
[39] Eames I.W., Wu S., Worall M., Aphornratana S.: An experimental investigation of steam ejectors for application in jet-pump refrigerators powered by low-grade heat. P. I. Mech. Eng. A-J Pow. A 213(1999), 5, 351–361. [40] Lee J.S., Kim M. Se, Kim M. Soo: Experimental study on the improvement of CO2 air conditioning system performance using an ejector. Int. J. Refrig. 34(2011), 7, 1614–1625.
[41] Bouzrara A.: Etude expérimentale des éjecteurs- application à la récupération de l’énergie de détente des machines frigorifiques au CO2. PhD thesis, INSA Lyon (CETHIL)-ENI Tunis 2018 (in French).
Go to article

Authors and Affiliations

Philippe Haberschill
1
Ezzeddine Nehdi
2
Lakdar Kairouani
2
Mouna Abouda Elakhdar
2

  1. University of Lyon, CNRS, INSA-Lyon, CETHIL UMR5008, F-69621, Villeurbanne, France
  2. Research Lab Energetic and Environment, National Engineering School of Tunis, Tunis El Manar University, Tunisia

This page uses 'cookies'. Learn more