<div>
	Numerical study on the straight, helical and spiral capillary tube for the CO<sub>2</sub> refrigerant</div>

Pravin Jadhav, Anjan Kumar Sahu, Sunita Ballal

2022 , VOLUME 22, NUMBER 4 ( July-August )

ISSN 2226-1494 (print), ISSN 2500-0373 (online)

Publications

Editor-in-Chief

Nikiforov
Vladimir O.
D.Sc., Prof.

Partners

doi: 10.17586/2226-1494-2022-22-4-804-811

Numerical study on the straight, helical and spiral capillary tube for the CO₂ refrigerant

J. Pravin, K. Anjan, B. Sunita

Read the full article

Article in English

For citation:

Jadhav P., Sahu A., Ballal S. Numerical study on the straight, helical and spiral capillary tube for the CO2 refrigerant. Scientific and Technical Journal of Information Technologies, Mechanics and Optics, 2022, vol. 22, no. 4, pp. 804–811. doi: 10.17586/2226-1494-2022-22-4-804-811

Abstract

A numerical study has been carried out for straight, spiral and helical capillary tubes and their performance has been compared with CO₂ refrigerant. The numerical models are developed based on the fundamental conservation principles of mass, momentum, and energy. Within this, outer loop, the ordinary differential equations are solved from the inlet to the exit of the capillary tube. The study has been carried out to calculate the mass flow rate by bisection method where the mass is iteratively calculated at the specified capillary length or vice versa. In-house coding programming employs the finite difference approach for numerical solutions. The characterization of the capillary tube has been done by calculating the length for the given mass or by calculating mass for the given length. The comparison of the straight capillary with helical capillary tube (50 mm coil diameter) and spiral capillary tube (50 mm pitch) has been reported. For a change in tube diameter, surface roughness, and length, the percentage reduction in mass flow rate in capillary tubes (straight, helical, and spiral) is calculated. The percentage reduction in mass in a helical capillary tube compared to the straight capillary tube is about 7–9 %. The percentage reduction in mass in a spiral tube compared to the straight capillary tube is nearly 23–26 %. Additionally, the percentage reduction in mass in a spiral tube compared to the helical capillary tube is almost 17–19 %. Additionally, the percentage reduction in length in a spiral tube compared to straight capillary tube ranges from 37 % to 43 %. Similarly, the percentage reduction in length in a spiral tube compared to helical capillary tube is ranging from 25 % to 32 %

Keywords: straight tube, helical tube, spiral tube, capillary tube, adiabatic, mass flow rate

References

Kim M., Pettersen J., Bullard C.W. Fundamental process and system design issues in CO₂ vapor compression systems. Progress in Energy and Combustion Science, 2004,vol. 30, no. 2, pp. 119–174.https://doi.org/10.1016/j.pecs.2003.09.002
Jadhav P.,Agrawal N. A review on flow characteristics of the straight and coiled capillary tubes. International Journal of Air-Conditioning and Refrigeration, 2021, vol. 29, no. 3, pp. 2130004.https://doi.org/10.1142/S2010132521300044
Stoecker W., Jones J. Refrigeration and Air Conditioning. 2^nd ed. McGraw-Hill, 1982, pp. 260–272.
Jabaraj D., Vettri Kathirvel A.,Mohan Lal D. Flow characteristics of HFC407C/HC600a/HC290 refrigerant mixture in adiabatic capillary tubes. Applied Thermal Engineering, 2006,vol. 26, no. 14-15, pp. 1621–1628.https://doi.org/10.1016/j.applthermaleng.2005.11.017
RastiM., JeongJ. Agene ralized continuo use mpirical correlation for the refrigerant mass flow rate through adiabaticstraight and helically coiled capillary tubes. Applied Therma lEngineering, 2018, vol. 143,pp. 450–460. https://doi.org/10.1016/j.applthermaleng.2018.07.124
Choi J., Kim Y., Kim H. A generalized correlation for refrigerant mass flow rate through adiabatic capillary tubes. International Journal of Refrigeration, 2003, vol. 26, no. 8, pp. 881–888.https://doi.org/10.1016/S0140-7007(03)00079-3
Chingulpitak S.,Wongwises S. Two-phase flow model of refrigerants flowing through helically coiled capillary tubes. Applied Thermal Engineering, 2010, vol. 30, no. 14-15, pp. 1927–1936.https://doi.org/10.1016/j.applthermaleng.2010.04.026
Jadhav P.,Agrawal N. Comparative study on a straight and helical capillary tube for CO2and R22 refrigerant. Journal of Thermal Science and Engineering Applications, 2021, vol. 13, no. 2,pp. 024502. https://doi.org/10.1115/1.4047822
Jadhav P.,Agrawal N. A comparative study of flow characteristics of adiabatic spiral and helical capillary tube in a CO₂transcritical system.International Journal of Ambient Energy,2021,in press. https://doi.org/10.1080/01430750.2021.1913645
Jadhav P.,Agrawal N. Flow behavior of spiral capillary tube for CO₂transcritical cycle.Journal of Thermal Analysis and Calorimetry, 2020,vol. 141, no. 6,pp. 2177–2188.https://doi.org/10.1007/s10973-020-09536-8
Mittal M., Kumar R.,Gupta A. Numerical analysis of adiabatic flow of refrigerant through a spiral capillary tube. International Journal of Thermal Sciences, 2009, vol. 48, no. 7,pp. 1348–1354.https://doi.org/10.1016/j.ijthermalsci.2009.01.003
Khan M., Kumar R.,Sahoo P. An experimental study of the flow of R-134a inside an adiabatic spirally coiled capillary tube. International Journal of Refrigeration, 2008, vol. 31,no. 6, pp. 970–978.https://doi.org/10.1016/j.ijrefrig.2008.01.008
Churchill S.W. Friction-factor equation spans all fluid-flow regimes.Chemical Engineering,1977, vol. 84, no. 24, pp. 91–92.
Mori Y., Nakayama W. Study on forced convective heat transfer in curve pipes II.International Journal of Heat and Mass Transfer, 1967, vol. 10,no. 1, pp. 37–59.https://doi.org/10.1016/0017-9310(67)90182-2
Ju H., Huang Z., Xu Y., Duan B., Yu Y.Hydraulic performance of small bending radius helical coil-pipe. Journal of Nuclear Science and Technology,2001, vol. 38, no. 10, pp. 826–831. https://doi.org/10.1080/18811248.2001.9715102

This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License