Comparative assessment of condensation and pool boiling heat transfer on horizontal plain single tubes for R1234ze(E), R1234ze(Z), and R1233zd(E)

Nagata, Ryuichi; Kondou, Chieko; Koyama, Shigeru

doi:10.1016/j.ijrefrig.2015.11.002

Cited by 61 publications

(11 citation statements)

References 30 publications

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“…In generally, it is not easy to judge which measurement value is correct in thermophysical property measurements. However, reliability of our data was able to be proved by measured condensation heat transfer coefficient by Nagata et al [9] where the experiments were carried out in the range of saturation temperature of 293.15 K and 313.15 K. The dotted and solid lines present the theoretically calculated heat transfer coefficient by Nusselt theory [10] with the viscosity values of REFPROP ver.9.1 and our data. As shown in figure, the experimental heat transfer coefficients agree well with Nusselt theory used our measured viscosity.…”

Section: Viscositysupporting

confidence: 62%

Developments of next generation refrigerants and heat transfer

Miyara

2018

MATEC Web Conf.

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Since the effect of refrigerants which are widely used in heat pump and refrigeration systems on the global warming has become a big environmental issue, researches and developments on the next generation refrigerants are being conducted intensively. Values of global warming potential (GWP) of most of currently used refrigerants are grater than 1000. R32 which becomes popular as a refrigerant of domestics air-conditioners for years has GWP=675. Recently, some hydrofluoroolefins (HFOs) are getting attention and their thermophysical properties and heat transfer characteristics are being clarified experimentally because GWP of HFOs are very small in which the values of some HFOs are less than 1 and those of others are less than around 10. For example, R1234yf and R1234ze(E) are promising candidate of R134a. In this paper, recent developments of the next generation refrigerants and its heat transfer characteristics are introduced.

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Section: Viscositysupporting

confidence: 62%

Developments of next generation refrigerants and heat transfer

Miyara

2018

MATEC Web Conf.

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“…As will be shown in the following model development, the ebullition part of the boiling heat flux is proportional to hfg ρv. Nagata et al (2016) presents boiling measurements on a smooth tube for several of the refrigerants of this study. The ratio of the Turbo-ESP heat transfer coefficient based on the projected area to the heat transfer coefficient of the smooth tube can be obtained by using the present measurements and the Nagata et al (2016) measurements at the same heat flux.…”

Section: Resultsmentioning

confidence: 99%

“…Nagata et al (2016) presents boiling measurements on a smooth tube for several of the refrigerants of this study. The ratio of the Turbo-ESP heat transfer coefficient based on the projected area to the heat transfer coefficient of the smooth tube can be obtained by using the present measurements and the Nagata et al (2016) measurements at the same heat flux. This enhancement ratio is equivalent to the smooth tube wall superheat divided by the Turbo-ESP wall superheat.…”

Section: Resultsmentioning

confidence: 99%

“…For example, no heat transfer studies were found in the literature that investigated the performance of R515A. Nagata et al (2016) measured both condensation and boiling on horizontal smooth tubes for R1234ze(E) and R1233zd(E). They found the measured boiling heat transfer coefficient of R1234ze(E) to be roughly 25 % larger than that of R134a and 333 % larger than that of R1233zd(E) at a saturation temperature of 283.15 K. Gorgy (2016) also made pool boiling measurements for R1234ze(E) and R1233zd(E); however, found that the performance of R134a to be similar to that of R1234ze(E).…”

Section: ____________________________________________________________mentioning

confidence: 99%

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Pool Boiling of R515A, R1234ze(E) and R1233zd(E) on a Reentrant Cavity Surface; Extensive Measurement and Analysis

Kedzierski¹,

Lin²

2019

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This paper quantifies the pool boiling performance of R515A, R1234ze(E), and R1233zd(E) on a flattened, horizontal Turbo-ESP surface for airconditioning applications for heat fluxes between roughly 10 kWm-2 and 100 kWm-2. Both R515A and R1234ze(E) are replacements for R134a, while R1233zd(E) is a replacement for R123. The measured boiling curve for R515A had roughly a 14 % larger heat flux than that of R1234ze(E) for heat fluxes greater than 45 kWm-2. For heat fluxes between 14 kWm-2 and 85 kWm-2 , R515A and R1234ze(E) exhibited a heat flux that was 33 % and 17 % larger than that for R134a. The heat flux of R1233zd(E) was roughly 18 % larger than that for R123 for heat fluxes between 30 kWm-2 and 87 kWm-2. A pool boiling model that was previously developed for pure and mixed refrigerants on the Turbo-ESP surface was improved by nondimensionalizing the model constants and improving their statistical significance. For most heat fluxes, the model predicted the measured superheat to within ± 0.7 K. The model was used to show that the vapor Prandtl number and the product of the latent heat and vapor density significantly influenced the boiling heat flux.

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“…A part from safety, toxicity, thermal stability and ecological effect another main attention to be paid is that the required refrigerant has equivalent thermo-dynamical and transport properties so that the equipment executes the heat transfer functions well. The low GWP refrigerant of R1234zd(E) is deliberated to be a prospective replacements for R134a, while isomers R1234ze(Z) and R1233zd(E) are expected to be low GWP alternatives for heat pump applications [55][56][57][58]. Condensation heat transfer across enhanced and plain surfaces is analyzed using low GWP refrigerants and comparisons are made.…”

Section: Experimental Heat Transfer Measurementsmentioning

confidence: 99%

An Overview of Recent Progress in Condensation Heat Transfer Enhancement Across Horizontal Tubes and the Tube Bundle

Bano

2021

Journal of Thermal Engineering

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The present paper presents a review of condensation heat transfer across smooth and enhanced horizontal surfaces due to its significance in refrigeration, air conditioning and heat pump applications. The emphasizes is on the recent understanding of experimental as well as the semi-empirical correlations to investigate the heat transfer phenomena during condensation associated with enhanced geometries. An effort has been made to submit freeconvection condensation effects outside of single tubes and the tube bundle with the influence of tube geometries, condensate retention and gravity on film condensation; however, comparison of forced convection is also presented. Alternative of conventional refrigerants in condensation process by low-global warming potential (GWP) refrigerants is addressed as well due to increase in atmospheric burden affected by hydro-fluoro-carbons (HFCs). Although many researchers have reviewed the condensation impact across enhanced surfaces, a few of them revised its behavior across pin-fin tubes. The effects of geometry, surface wettability, and operating conditions on the location, amount and form of condensate film are discussed. Various theoretical models prediction with the new experimental data across pin-fin tubes is also revealed. This review is distributed into two main sections: the first section focuses on condensation across enhanced tubes, sub dividing the study into integral-fin and pin-fin tubes based on theoretical and experimental investigations. It covers the geometrical effects concerning three dimensional (3D) surfaces, fin density, fin spacing and fin thickness. The later part of the paper concentrates on condensation behavior across the tube bundle incorporating the effects of fin density and refrigerant mixtures highlighting both theoretical and experimental knowledge. Recent research shows an agreement between theoretical and experimental models in the defined area; though, a considerable amount of work on semi-empirical correlation formulation is visible in the literature. The strength of this paper is the latest findings on condensation against different geometrical parameters of extended surfaces specifically across pin-fin tubes and the tube bundle. Finally, theoretical enhancement factors along with many heat transfer correlations are presented and recommendations are suggested for the future work.

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Comparative assessment of condensation and pool boiling heat transfer on horizontal plain single tubes for R1234ze(E), R1234ze(Z), and R1233zd(E)

Cited by 61 publications

References 30 publications

Developments of next generation refrigerants and heat transfer

Developments of next generation refrigerants and heat transfer

Pool Boiling of R515A, R1234ze(E) and R1233zd(E) on a Reentrant Cavity Surface; Extensive Measurement and Analysis

An Overview of Recent Progress in Condensation Heat Transfer Enhancement Across Horizontal Tubes and the Tube Bundle

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