Detail publikačního výsledku

Evaporation of refrigerant R134a, R404A and R407C with low mass flux in smooth vertical tube

HORÁK, P.; FORMÁNEK, M.; FEČER, T.; PLÁŠEK, J.

Originální název

Evaporation of refrigerant R134a, R404A and R407C with low mass flux in smooth vertical tube

Anglický název

Evaporation of refrigerant R134a, R404A and R407C with low mass flux in smooth vertical tube

Druh

Článek WoS

Originální abstrakt

This experimental study analysis the low mass flux of refrigerant R134a, R404A, and R407C in the smooth vertical evaporator tube with an inner diameter of 32 mm. This downward-flow refrigerant with a mass flux of about 9 kg m −2 s −1 in the parallel/counter flow of heating water shows suppressed heat trans- fer by convective boiling and dominant heat transfer by nucleate boiling. This dominant heat transfer by nucleate boiling is dependent on the superheated wall of evaporator tube. The experimentally obtained Nusselt number correlates 92.2 % for R134a, 92.4 % for R404A, and 83.2 % for R407C with the predicted Nusselt number for mass flux over 10 kg m −2 s −1 . In summary, the untypically low mass flux of refrig- erant about 9 kg m −2 s −1 is comparable with the current state of knowledge for low mass flux over 10 kg m −2 s −1 .

Anglický abstrakt

This experimental study analysis the low mass flux of refrigerant R134a, R404A, and R407C in the smooth vertical evaporator tube with an inner diameter of 32 mm. This downward-flow refrigerant with a mass flux of about 9 kg m −2 s −1 in the parallel/counter flow of heating water shows suppressed heat trans- fer by convective boiling and dominant heat transfer by nucleate boiling. This dominant heat transfer by nucleate boiling is dependent on the superheated wall of evaporator tube. The experimentally obtained Nusselt number correlates 92.2 % for R134a, 92.4 % for R404A, and 83.2 % for R407C with the predicted Nusselt number for mass flux over 10 kg m −2 s −1 . In summary, the untypically low mass flux of refrig- erant about 9 kg m −2 s −1 is comparable with the current state of knowledge for low mass flux over 10 kg m −2 s −1 .

Klíčová slova

Mass flux Heat flux Vapour quality Heat transfer coefficient Nusselt number

Klíčová slova v angličtině

Mass flux Heat flux Vapour quality Heat transfer coefficient Nusselt number

Autoři

HORÁK, P.; FORMÁNEK, M.; FEČER, T.; PLÁŠEK, J.

Rok RIV

2022

Vydáno

21.09.2021

Nakladatel

Elsevier

Místo

United Kingdom

ISSN

0017-9310

Periodikum

INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER

Svazek

181

Číslo

1

Stát

Spojené království Velké Británie a Severního Irska

Strany od

1

Strany do

8

Strany počet

8

URL

https://www.sciencedirect.com/science/article/pii/S0017931021009509

Plný text v Digitální knihovně

http://hdl.handle.net/

BibTex

@article{BUT172543,
  author="Petr {Horák} and Marian {Formánek} and Tomáš {Fečer} and Josef {Plášek}",
  title="Evaporation of refrigerant R134a, R404A and R407C with low mass flux in smooth vertical tube",
  journal="INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER",
  year="2021",
  volume="181",
  number="1",
  pages="1--8",
  doi="10.1016/j.ijheatmasstransfer.2021.121845",
  issn="0017-9310",
  url="https://www.sciencedirect.com/science/article/pii/S0017931021009509"
}