DOCSLIB.ORG

Experimental Study and Modelling Heat Transfer During Condensation

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Experimental Study and Modelling Heat Transfer During Condensation Experimental study and modelling heat transfer during condensation of pure fluid and binary mixtures ona bundle of finned tubes Mourad Belghazi, André Bontemps, Christophe Marvillet To cite this version: Mourad Belghazi, André Bontemps, Christophe Marvillet. Experimental study and modelling heat transfer during condensation of pure fluid and binary mixtures on a bundle of finned tubes. Interna- tional Journal of Refrigeration, Elsevier, 2003, 26 (2), pp.214-223. 10.1016/S0140-7007(02)00042-7. hal-00184124 HAL Id: hal-00184124 https://hal.archives-ouvertes.fr/hal-00184124 Submitted on 11 Feb 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Distributed under a Creative Commons Attribution| 4.0 International License Experimental study and modelling of heat transfer during condensation of pure fluid and binary mixture on a bundle of horizontal finned tubes M. Belghazia, A. Bontempsb,*, C. Marvilleta,1 aGroupement pour la Recherche sur les Echangeurs thermiques (GRETh), Commissariat a` l’Energie Atomique, 17, rue des Martyrs, 38054 Grenoble Cedex 9, France bLEGI/GRETh, Universite´ Joseph Fourier, Grenoble, France An experimental investigation was conducted to measure the local heat transfer coefficient for each row in a trape- zoidal finned horizontal tube bundle during condensation of both pure fluid (HFC 134a) and several compositions of the non-azeotropic binary mixture HFC 23/HFC 134a. The test section is a 13Â3 (rows  columns) tube bundle and the heat transfer coefficient is measured using the modified Wilson plot method. The inlet vapour temperature is fixed at 40 C and the water flow rate in each active row ranges from 170 to 600 l/h. The test series cover five different finned tubes all commercially available, K11 (11 fins/inch), K19 (19 fins/inch), K26 (26 fins/inch), K32 (32 fins/inch), K40 (40 fins/inch) and their performances were compared. The experimental results were checked against available models predicting the heat transfer coefficient during condensation of pure fluids on banks of finned tubes. Modelling of heat exchange during condensation of binary mixtures on bundles of finned tubes based on the curve condensation model is presented. Keywords: Heat transfer; Mass transfer; Condensation; Refrigerant; Binary mixture; Finned tube; Exterior; Bundle; Heat transfer coefficient; Measurement; Modelling * Corresponding author. Tel.: +33-4-3878-3155; fax: +33-4-3878-5172. E-mail address: [email protected] (A. Bontemps). 1 Nomenclature Greek letters avg vapour phase mean heat transfer coefficient a thermal diffusivity (m2 sÀ1) in the bundle (W mÀ2 KÀ1) À2 A ratio of the total to the plain tube e vapour-side heat transfer coefficient (W m surfaces KÀ1) À2 À1 b fin spacing (m) i inner heat transfer coefficient (W m K ) À1 À1 Cp specific heat capacity (J kg K ) l heat transfer coefficient in the liquid phase 2 À1 À2 À1 D1,2 mass diffusivity (m s ) (W m K ) De diameter at the fin tip (m) v local heat transfer coefficient in the vapour À2 À1 Dh hydraulic diameter (m) phase (W m K ) Di inner diameter (m) inundation coefficient Dr Diameter at the fin root (m) enhancement factor e fin height (m) l thermal conductivity (W mÀ1 KÀ1) F correction factor È flooding angle (rad) g gravity (m sÀ2) halph angle at the fin tip (rad or degree) À1 À1 hm specific enthalpy (J kg ) surface tension (N m ) j row index K constant Subscripts : m mass flow rate (kg sÀ1) c coolant N row number g gas p fin pitch (m) G Gnielinski P pressure (N mÀ2) in inlet q heat flux (W mÀ2) j row index Q heat flow rate (W) l liquid S exchange surface area (m2) out outlet t fin thickness (m) T total T temperature (K) v vapour U overall heat transfer coefficient w wall (W mÀ2 KÀ1) v vapour velocity (m sÀ1) Dimensionless numbers xg vapour quality Le Lewis number y HFC23 mass fraction Nu Nusselt number Z: Bell and Ghaly parameter Pr Prandtl number Z modified Bell and Ghaly parameter Re Reynolds number 1. Introduction to underline the influence of the fin pitch, (ii) to study condensation of several compositions of the In the European context where existing and new binary mixture (HFC 23/HFC 134a), (iii) to under- refrigerating machines have to be adapted to HFCs stand heat transfer in enhanced tube banks both (HydroFluoroCarbons), the questions asked of heat with pure fluids and with mixtures, and (iv) to model exchanger designers and thermal engineers generally heat transfer in tube bundles during condensation of fall into two groups. The first concerns the behaviour zeotropic mixtures by means of the equilibrium method. of traditionally designed TEMA X1 condensers which have to operate with retrofitting refrigerants especially 2. A short review of relevant works with zeotropic mixtures. The second covers the optimi- sation of the TEMA X condenser to pure HFCs as HFC 2.1. Pure fluid case 134a and to mixed refrigerants (e.g. HFC 407C). To answer the both items, the present study, which Theoretical models to predict the heat transfer coeffi- expands on a preliminary study on smooth tube bundles cient (HTC) for single low-finned tubes have been well [1], deals with the experimental evaluation of heat developed since the 19400s, in particular with the pio- transfer performance of tube bundles equipped with neering work of Beatty and Katz [2]. Their model finned tubes whose density ranges from 11 to 40 fpi. assumed that the condensate is drained only via gravity. The present work has four aims: (i) to study con- Gregorig [3] was the first author to develop a model of densation outside five different finned tubes in order condensation around profiled surfaces, taking into 2 account only the surface tension forces. A review of finned tubes during condensation of the binary mixture surface tension effects during condensation of pure (90% R113+ 10% R114) and they found that the tube fluids is given by Shah et al. [4]. with high fins (3 mm) is better than the one with small Theoretical models combining both gravity and sur- fins (0.8 mm), contrary to the condensation of pure face tension forces are used to predict the HTC of a fluids. Honda et al. [14] conducted experiments during single horizontal tube with sufficient accuracy. Rose [5] condensation of a downward-flowing zeotropic mixture proposed a semi-empirical model for a horizontal tube HFC123/HFC134a (about 9% HFC134a at the test having trapezoidal fins. To compare his model to section inlet), on a 13  15 (columns  rows) staggered experimental results, Rose [5] used various finned tubes bundle of horizontal low finned tubes. Their experi- with different fin pitchs, heights and diameters as well as mental data show that both the heat and mass transfer various fluids (water, ethylene glycol, methanol, R113, coefficients increase with the row number up to the R11, R12...). He found a deviation of 12.4% from the third (or the second) row, then decrease mono- experimental data used. tonically with increasing row number, finally to The foregoing models for a single tube are not increase at the last row. To correlate their results directly applicable to tube banks, since heat transfer in they proposed a dimensionless correlation of the mass the lower rows is affected by condensate inundation and transfer coefficient based on the analogy between heat the HTC is lower for these tubes. In the literature there and mass transfer. are two approaches to this problem. The first simply consists of multiplication of the HTC for a single tube by a factor less than unity, taking into account the row 3. Experimental apparatus position in the bundle. The second, more accurate, con- sists in the development of a model, first for a single The experimental apparatus consists of a thermosi- tube, and then for a bundle. Such a model was proposed phon refrigerant loop and a forced circulation coolant by Honda and Nozu [6,7] based on a bidimensional (water) loop (Fig. 1). The test rig used in this investiga- analysis of the film condensate. Murata and Hashizume tion is the same as that of a previous study [1]. In the [8] developed a model predicting the HTC of tube bun- refrigerant loop the vapour is generated in a boiler dles having rectangular fins. To validate their model heated with hot water which is itself heated by an elec- they compared it to experimental data during con- tric heater. The vapour flows towards the test section, densation of R11 and R114 in bundles of eight rows, passes vertically downwards and condenses outside the with rectangular fin tubes of various fin pitches. Theory water cooled tubes. The test section (Fig. 2) is a stainless and experiments differed by about 20%. steel duct and contains a staggered copper tube bank There are few experiments on the condensation of consisting of 13 rows, each of two (even rows) or three HFC134a on low finned tubes. In the work of Blanc [9], tubes (odd rows). In Fig. 2 the cross-hatched tubes are the HTC on trapezoidal fin tubes (K26) is compared dummies (no heat exchange), while the others are active. with current theories. In particular, the Honda model Half tubes are attached to the vertical walls of the test underestimates by up to À30% the inundation effect of section in order to eliminate vapour by-pass.
Load more

Recommended publications
  • The Use of Organic Zeotropic Mixture with High Temperature Glide As a Working Fluid in Medium-Temperature Vapor Power Plant
    Borsukiewicz, A.: The Use of Organic Zeotropic Mixture with … THERMAL SCIENCE, Year 2017, Vol. 21, No. 2, pp. 1153-1160 1153 THE USE OF ORGANIC ZEOTROPIC MIXTURE WITH HIGH TEMPERATURE GLIDE AS A WORKING FLUID IN MEDIUM-TEMPERATURE VAPOR POWER PLANT by Aleksandra BORSUKIEWICZ* ORC Power Plants Research and Development Centre, West Pomeranian University of Technology, Szczecin, Poland Original scientific paper https://doi.org/10.2298/TSCI141120088B The paper presents the idea of using organic substances as working fluids in va- por power plants, in order to convert the low and medium temperature thermal energy sources into electrical energy. The calculation results of the power plant efficiency for butane-ethane zeotropic mixtures of different mass compositions, for the power plant supplied with hot water having a temperature of 120 °C. Based on the results of thermal-flow calculations it was found that the use of zeo- tropic mixture does not allow to increase the efficiency and output of the power plant (these values appeared as slightly lower ones). However, it was found that, through the selection of a mixture of sufficiently large temperature glide, the heat exchange surface of the condenser can be reduced or a co-generation system can be implemented. Key words: organic Rankine cycle, zeotropic mixture, high temperature glide Introduction Energy, except at food production and medicine, is the most important aspect of hu- man development, having a direct impact on quality of life. The search for new sources of ener- gy, especially from renewables and waste, and more efficient ways of energy conversion into usable forms are all currently under intensive development.
    [Show full text]
  • In-Tube Condensation of Zeotropic Refrigerant R454C from Superheated Vapor to Subcooled Liquid Tabeel A
    In-Tube Condensation of Zeotropic Refrigerant R454C from Superheated Vapor to Subcooled Liquid Tabeel A. Jacoba and Brian M. Fronka* a School of Mechanical, Industrial and Manufacturing Engineering Oregon State University Corvallis, OR 97331, USA, * Corresponding Author: Email: [email protected] Tabeel A. Jacob (Student Member ASHRAE) is a graduate research assistant in the School of Mechanical, Manufacturing and Mechanical Engineering (MIME), Oregon State University, Corvallis, OR. Brian M. Fronk (Associate Member ASHRAE) is an assistant professor in the School of MIME, Oregon State University, Corvallis, OR In-Tube Condensation of Zeotropic Refrigerant R454C from Superheated Vapor to Subcooled Liquid ABSTRACT This paper investigates the in-tube, superheated, saturated and subcooled condensation of zeotropic refrigerant mixture R454C. R454C is proposed to replace R404A for commercial refrigeration applications. Quasi-local heat transfer coefficients were measured in a 4.7 mm horizontal tube at mass fluxes ranging from 100 – 500 kg m-2 s-1 at three different saturation conditions (40, 50 and 50 °C). The resulting data was compared with the non- equilibrium condensation models of Agarwal & Hrnjak (2014), Kondou & Hrnjak (2012) and Xiao & Hrnjak (2017), as well as the equilibrium model of Cavallini et al. (2006) with the Gnielinski (1976) correlation for predictions in subcooled and saturated regions. The additional mass transfer effects were accounted for by applying the Silver (1947), Bell & Ghaly (1973) mixture correction. The non-equilibrium Kondou & Hrnjak (2012) model, with the predictions in the subcooled region from Gnielinski (1976) correlation, agrees best with the data (mean average percent error = 9%). An air-cooled condenser for a 1055 kW refrigeration system is designed by following both the non-equilibrium and equilibrium approaches.
    [Show full text]
  • Postprint Zeotropic
    Downloaded from orbit.dtu.dk on: Oct 05, 2021 A review of recent research on the use of zeotropic mixtures in power generation systems Modi, Anish; Haglind, Fredrik Published in: Energy Conversion and Management Link to article, DOI: 10.1016/j.enconman.2017.02.032 Publication date: 2017 Document Version Peer reviewed version Link back to DTU Orbit Citation (APA): Modi, A., & Haglind, F. (2017). A review of recent research on the use of zeotropic mixtures in power generation systems. Energy Conversion and Management, 138, 603–626. https://doi.org/10.1016/j.enconman.2017.02.032 General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. Users may download and print one copy of any publication from the public portal for the purpose of private study or research. You may not further distribute the material or use it for any profit-making activity or commercial gain You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. A review of recent research on the use of zeotropic mixtures in power generation systems Anish Modia,∗, Fredrik Haglindb aDepartment of Energy Science and Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, Maharashtra, India bDepartment of Mechanical Engineering, Technical University of Denmark, Nils Koppels All´e,Building 403, DK-2800 Kgs.
    [Show full text]
  • Experimental Study and Optimization of the Organic Rankine Cycle with Pure Novectm649 and Zeotropic Mixture Novectm649/HFE7000 As Working Fluid
    applied sciences Article Experimental Study and Optimization of the Organic Rankine Cycle with Pure NovecTM649 and Zeotropic Mixture NovecTM649/HFE7000 as Working Fluid Quentin Blondel 1,2,*, Nicolas Tauveron 1, Nadia Caney 2 and Nicolas Voeltzel 1 1 Department LITEN, University Grenoble Alpes, CEA, LITEN, L2ST, 38054 Grenoble, France; [email protected] (N.T.); [email protected] (N.V.) 2 Department LEGI, University Grenoble Alpes, CNRS, LEGI, 38000 Grenoble, France; [email protected] * Correspondence: [email protected] Received: 18 April 2019; Accepted: 5 May 2019; Published: 7 May 2019 Featured Application: This work shows the interest in new low Global Warming Potential replacement fluids for Organic Rankine Cycles and suggests the use of zeotropic mixtures to improve Organic Rankine Cycle systems. Abstract: The Organic Rankine Cycle (ORC) is widely used in industry to recover low-grade heat. Recently, some research on the ORC has focused on micro power production with new low global warming potential (GWP) replacement working fluids. However, few experimental tests have investigated the real performance level of this system in comparison with the ORC using classical fluids. This study concerns the experimental analysis and comparison of a compact (0.25 m3) Organic Rankine Cycle installation using as working fluids the NovecTM649 pure fluid and a zeotropic mixture composed of 80% NovecTM649 and 20% HFE7000 (mass composition) for low-grade waste heat conversion to produce low power. The purpose of this experimental test bench is to study replacement fluids and characterize them as possible replacement fluid candidates for an existing ORC system. The ORC performance with the pure fluid, which is the media specifically designed for this conversion system, shows good results as a replacement fluid in comparison with the ORC literature.
    [Show full text]
  • Analysis of Zeotropic Mixture in a Geothermal Organic Rankine Cycle Power Plant with an Air-Cooled Condenser H
    ANALYSIS OF ZEOTROPIC MIXTURE IN A GEOTHERMAL ORGANIC RANKINE CYCLE POWER PLANT WITH AN AIR-COOLED CONDENSER H. C. Jung1 and Susan Krumdieck2 1,2Department of Mechanical Engineering, University of Canterbury, Private Bag 4800, Christchurch 8041, New Zealand [email protected] [email protected] Keywords: Working fluid, Zeotropic mixture, Air-cooled The working fluid plays a vital role in the energy conversion Condenser, Geothermal, Organic Rankine cycle. efficiency of ORC machine. Numerous studies have been focused on the proper selection of pure fluids, including ABSTRACT refrigerants such as R-134°, R-123 and R-245fa and volatile The purpose of this research is to investigate a zeotropic hydrocarbons such as butane and pentane (Saleh et. al., working fluid mixture in terms of its performance in an 2007, Wang et. al., 2011). General selection criteria for a organic Rankine cycle (ORC) and the heat transfer potential fluid were proposed by Chen et. al. (2010). characteristics in an air-cooled condenser (ACC). The motivation of this study is that it is well known that the use The suggestion of using a working fluid mixture in vapour of a mixture improves the efficiency of an ORC system. compression systems was first made in 1888 by Pictet However, the behaviour of the mixture in the condensers is (Radermacher 1989). The benefits of using organic fluid not well understood. A standard ORC unit utilising hot mixtures as the working fluid in ORC systems were spring water to generate electricity is considered for the investigated by Angelino and Paliano (1998). By using a analysis.
    [Show full text]
  • Impact of Refrigerants R1234yf, R455A, R454C on the Behaviour of Direct Expansion Refrigeration Circuits
    Impact of refrigerants R1234yf, R455A, R454C on the behaviour of direct expansion refrigeration circuits Table of contents 1. Context: ........................................................................................................................................... 3 2. Refrigerants environmental data: ................................................................................................... 4 2.1. ISO 817 rating .......................................................................................................................... 4 2.2. Definition – Refrigerants composition .................................................................................... 4 2.3. Environmental data ................................................................................................................. 4 2.4. Some safety data ..................................................................................................................... 5 3. Thermodynamic data ...................................................................................................................... 5 3.1. Refrigerant R1234yf ................................................................................................................ 5 3.1.1. Mollier diagram ................................................................................................................... 6 3.1.2. Temperatures-Pressures curves .......................................................................................... 7 3.2. Refrigerants R455A - R454C ...................................................................................................
    [Show full text]
  • Experimental Study of Zeotropic Refrigerant Mixture HFC-407C As a Replacement for HCFC-22 in Refrigeration and Air Conditioning Systems
    Experimental study of Zeotropic refrigerant mixture HFC-407C as a replacement for HCFC-22 in Refrigeration and air conditioning systems By Changiz M. Tolouee B. Sc. (Mech. Eng.) and M. Sc. (Mech. Eng.) A thesis submitted for the degree of DOCTOR OF PHILOSOPHY School of Engineering and Science Swinburne University of Technology 2006 1 DECLARATION This thesis contains no material which has been accepted for the award of any other degree or diploma, except where due reference is made in the text of the thesis. To the best of my knowledge, this thesis contains no material previously published or written by another person except where due reference is made in the text of the thesis. Signed ……………………………. 2 ABSTRACT HCFC-22 is the world’s most widely used refrigerant. It serves in both residential and commercial applications, from small window units to large water chillers, and everything in between. Its particular combination of efficiency, capacity and pressure has made it a popular choice for equipment designers. Nevertheless, it does have some ODP, so international law set forth in the Montreal Protocol and its Copenhagen and Vienna amendments have put HCFC-22 on a phase out schedule. In developed countries, production of HCFC-22 will end no later than the year 2030. Zeotropic blend HFC-407C has been established as a drop-in alternative for HCFC-22 in the industry due to their zero Ozone Depletion Potential (ODP) and similarities in thermodynamic properties and performance. However, when a system is charged with a zeotropic mixture, it raises concerns about temperature glide at two-phase state, differential oil solubility and internal composition shift.
    [Show full text]
  • Temperature Glide Matching in a Zeotropic Mixture Heat Pump
    PROCEEDINGS OF ECOS 2017 - THE 30TH INTERNATIONAL CONFERENCE ON EFFICIENCY, COST, OPTIMIZATION, SIMULATION AND ENVIRONMENTAL IMPACT OF ENERGY SYSTEMS JULY 2-JULY 6, 2017, SAN DIEGO, CALIFORNIA, USA Temperature glide matching in a zeotropic mixture heat pump V. Venzika and B. Atakanb a University of Duisburg-Essen, Thermodynamics, Duisburg, Germany, [email protected] b University of Duisburg-Essen, Thermodynamics, Duisburg, Germany, [email protected] Abstract: The use of zeotropic mixtures in heat pumps should lead to a reduction of the exergy losses within the heat exchangers due to the temperature glide (TG) and thus to an improvement of the entire process. In a previous publication (ECOS 2016), the coefficient of performance (COP) as a function of evaporation / condensation temperature, compressor rotation speed and composition of a zeotropic mixture (isobutane / propene) was investigated. Contrary to theoretical analysis, it was shown that the COPs of the mixtures increase only slightly compared to the better performing pure fluid. The temperature change of the secondary fluid in the heat exchangers was relatively small. In the present work, it is experimentally investigated whether a better matching of the temperature glide in the evaporator raises the COP of a zeotropic mixture compared to the better performing pure fluid. The targeted utilization of the TG is achieved by matching the temperature variation of the mixture and the temperature variation of the heat source; this was adjusted by varying the heat capacity flowrate of the source. An isobutane/propene mixture (42:58) with a TG of 8.03 K is investigated as the working fluid, together with investigations of the pure fluids isobutane and propene, all for equal boundary conditions.
    [Show full text]
  • In-Tube Condensation of Zeotropic Refrigerant R454C from Superheated Vapor to Subcooled Liquid
    In-Tube Condensation of Zeotropic Refrigerant R454C from Superheated Vapor to Subcooled Liquid ABSTRACT This paper investigates the in-tube, superheated, saturated and subcooled condensation of zeotropic refrigerant mixture R454C. R454C is proposed to replace R404A for commercial refrigeration applications. Quasi-local heat transfer coefficients were measured in a 4.7 mm horizontal tube at mass fluxes ranging from 100 – 500 kg m-2 s-1 at three different saturation conditions (40, 50 and 50 °C). The resulting data was compared with the non- equilibrium condensation models of Agarwal & Hrnjak (2014), Kondou & Hrnjak (2012) and Xiao & Hrnjak (2017), as well as the equilibrium model of Cavallini et al. (2006) with the Gnielinski (1976) correlation for predictions in subcooled and saturated regions. The additional mass transfer effects were accounted for by applying the Silver (1947), Bell & Ghaly (1973) mixture correction. The non-equilibrium Kondou & Hrnjak (2012) model, with the predictions in the subcooled region from Gnielinski (1976) correlation, agrees best with the data (mean average percent error = 9%). An air-cooled condenser for a 1055 kW refrigeration system is designed by following both the non-equilibrium and equilibrium approaches. This non-equilibrium approach leads to a 4.8% and 9.1% reduction in heat transfer area for R454C and R404A, respectively. R454C condenser area is 17-21% larger than that of a R404A condenser. Preprint submitted to Science and Technology for the Built Environment June 26, 2020 INTRODUCTION Flammability, decreased system performance and increased equipment size are some of the critical risks of implementing new, lower global warming potential (GWP) refrigerants in the heating, ventilation, air conditioning, and refrigeration (HVAC&R) industry.
    [Show full text]
  • The Circulation Composition Characteristic of the Zeotropic Mixture R1234ze(E)/R32 in a Heat Pump Cycle
    Purdue University Purdue e-Pubs International Refrigeration and Air Conditioning School of Mechanical Engineering Conference 2012 The irC culation Composition Characteristic of the Zeotropic Mixture R1234ze(E)/R32 in a Heat Pump Cycle Sho Fukuda [email protected] Nobuo Takata Shigeru Koyama Follow this and additional works at: http://docs.lib.purdue.edu/iracc Fukuda, Sho; Takata, Nobuo; and Koyama, Shigeru, "The irC culation Composition Characteristic of the Zeotropic Mixture R1234ze(E)/R32 in a Heat Pump Cycle" (2012). International Refrigeration and Air Conditioning Conference. Paper 1221. http://docs.lib.purdue.edu/iracc/1221 This document has been made available through Purdue e-Pubs, a service of the Purdue University Libraries. Please contact [email protected] for additional information. Complete proceedings may be acquired in print and on CD-ROM directly from the Ray W. Herrick Laboratories at https://engineering.purdue.edu/ Herrick/Events/orderlit.html 2229, Page 1 The Circulation Composition Characteristic of the Zeotropic Mixture R1234ze(E)/R32 in a Heat Pump Cycle Sho FUKUDA1*, Nobuo TAKATA1, and Shigeru KOYAMA2 1 Interdisciplinary Graduate School of Engineering Sciences, Kyushu University Kasuga, Fukuoka, 816-8580, Japan Phone: +81-92-583-7840, Fax: +81-92-583-7833, E-mail: [email protected] 2 Faculty of Engineering Sciences, Kyushu University Kasuga, Fukuoka, 816-8580, Japan Phone: +81-92-583-7831, Fax: +81-92-583-7833, E-mail: [email protected] ABSTRACT This study presents an experimental investigation of the circulation composition in a heat pump cycle for considering the effect of its difference from the charged composition on the cycle performance prediction.
    [Show full text]
  • Zeotropic Mixture Selection for an Organic Rankine Cycle Using a Single Screw Expander
    energies Article Zeotropic Mixture Selection for an Organic Rankine Cycle Using a Single Screw Expander Xinxin Zhang 1,2,* , Yin Zhang 1,2, Zhenlei Li 1,2, Jingfu Wang 1,2, Yuting Wu 1,2 and Chongfang Ma 1,2 1 MOE Key Laboratory of Enhanced Heat Transfer and Energy Conservation, College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124, China; [email protected] (Y.Z.); [email protected] (Z.L.); [email protected] (J.W.); [email protected] (Y.W.); [email protected] (C.M.) 2 Beijing Key Laboratory of Heat Transfer and Energy Conversion, College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124, China * Correspondence: [email protected]; Tel.: +86-10-6739-1985 Received: 20 December 2019; Accepted: 21 February 2020; Published: 25 February 2020 Abstract: The organic Rankine cycle (ORC) is a popular and promising technology that has been widely studied and adopted in renewable and sustainable energy utilization and low-grade waste heat recovery. The use of zeotropic mixtures in ORC has been attracting more and more attention because of the possibility to match the temperature profile of the heat source by non-isothermal phase change, which reduces the irreversibility in the evaporator and the condenser. The selection of working fluid and expander is strongly interconnected. As a novel expander, a single screw expander was selected and used in this paper for efficient utilization of the wet zeotropic mixtures listed in REFPROP 9.1 in a low-temperature subcritical ORC system. Five indicators, namely net work, thermal efficiency, heat exchange load of condenser, temperature glide in evaporator, and temperature glide in condenser, were used to analyze the performance of an ORC system with wet and isentropic zeotropic mixtures as working fluids.
    [Show full text]
  • 2-6 Azeotropic/Zeotropic Refrigerants
    Republic of Iraq Ministry of Higher Education & Scientific Research Northern Technical University Technical Institute /Kirkuk Equipments & Machineries Dep./ Branch of Ref. & Air Conditioning A Research Submitted to ((Equipments & Machineries Dep./ Branch of Ref. & Air Conditioning)) Prepared by Ibrahim Najmaldeen Mahmood Jalal Ali Asgher Ahmed Bahir Mohammed Ibrahim Ahmed Mohammed George Odisho Bawith Supervised by 2018 1439 بِسْمِ ِهللا الرَّحْمهِ الرَّحٍِم ِ ﴿ رَبِّ أَوْزِعْىًِ أَنْ أَشْكُرَ وِعَْمتَكَ التًِ أَوعمت علً وعلى واِلدي َّ ََْْ َََّ َََ َ َ َّ وَأَنْ أَعَْملَ صَاِلحًا َترْضَاُي وَأَدْخِلْىًِ بِرَحَْمتِكَ فًِ عِبَادِك الصَّاِلحٍِه ﴾ صدق هللا العظٍم ََ ْ (19) اﻻٌت سورة الىمل إليي ﻻ يطيب الميل إﻻ بشكرك وﻻ يطيب النيار إﻻ بطاعتك .. وﻻ تطيب المحظات إﻻ بذكرك .. وﻻ تطيب اﻵخرة إﻻ بعفوك .. وﻻ تطيب الجنة إﻻ برؤيتك .. اذا كان اﻻىداء يعبر ولو بجزء من الوفاء فاﻻىداء إلى من بمغ الرسالة وأدى اﻷمانة .. ونصح اﻷمة .. إلى نبي الرحمة ونور العالمين .. الى الوالدين الحبيبين الشموع التي تنير لنا دروب الحياة .. الى اخواننا و اخواتنا الذين يؤازرونا ويدعموننا.. الى كل صديق اضاف لنا تقدما في الحياة .. الى اساتذتنا و مربونا .. الــــــى من ميدوا الطريق امامنا لموصول الى ىذه المرحمة نيدي لكم ثمرة جيدنا واجتيادنا .. الباحثون "كن عالما .. فإن لم تستطع فكن متعمما ، فإن لم تستطع فأحب العمماء ،فإن لم تستطع فﻻ تبغضيم" بعد رحمة بحث و جيد و اجتياد تكممت بإنجاز ىذا البحث ، نحمد اهلل عز وجل عمى نعمو التي انعميا عمينا فيو العمي القدير ، كما ﻻ يسعنا إﻻ أن نخص بأسمى عبارات الشكر و التقدير لﻷستاذة.. كما نتقدم بالشكر الجزيل لكل من أسيم في تقديم يد العون ﻹنجاز ىذا البحث، و نخص بالذكر أستاذتنا الكرام الذين أشرفوا عمى تكوين دفعة.
    [Show full text]