Pressure-drop reduction and heat-transfer deterioration of slush nitrogen in horizontal pipe flow

Cryogenics ◽  
2011 ◽  
Vol 51 (10) ◽  
pp. 563-574 ◽  
Author(s):  
Katsuhide Ohira ◽  
Kei Nakagomi ◽  
Norifumi Takahashi
2015 ◽  
Vol 67 ◽  
pp. 681-686 ◽  
Author(s):  
Katsuhide Ohira ◽  
Kei Nakagomi ◽  
Koichi Takahashi ◽  
Itsuo Aoki

1997 ◽  
Vol 33 (1-2) ◽  
pp. 109-120 ◽  
Author(s):  
T. Aihara ◽  
K. Yamamoto ◽  
K. Narusawa ◽  
T. Haraguchi ◽  
M. Ukaku ◽  
...  

2015 ◽  
Author(s):  
Jessica Lorrany Ferreira Barbosa ◽  
Diego Lourenço da Costa Felipe ◽  
Distefano Lima Martins Barbosa ◽  
Marcelo de Oliveira e Silva ◽  
Danielle Regina da Silva Guerra ◽  
...  

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6886
Author(s):  
Małgorzata Sikora ◽  
Tadeusz Bohdal ◽  
Karolina Formela

This article presents the results obtained from our own experimental investigations on heat exchange and pressure drop during the condensation flow of the HFE 7000 refrigerant in pipe minichannels with an internal diameter of di = 1.2–2.5 mm. The influence of vapor quality x and the mass flux density G on the two-phase flow pressure drops and heat transfer is presented. The tests were performed for the mass flux density range of G = 110–4700 kg/m2s, saturation inlet temperature of Ts = 36–43 °C and heat flux density of q = 1 ÷ 20 kW/m2. The pressure drop characteristics and heat transfer coefficient as a function of the internal diameter of minichannels are illustrated. The results of experimental research on the heat transfer coefficient and two-phase pressure drop are compared with correlations developed by other authors. The best accuracy has a comparison of experimental study with correlation of Rahman-Kariya-Miyara et al. and Mikielewicz et al.


Cryogenics ◽  
2017 ◽  
Vol 81 ◽  
pp. 60-75 ◽  
Author(s):  
Katsuhide Ohira ◽  
Kizuku Kurose ◽  
Jun Okuyama ◽  
Yutaro Saito ◽  
Koichi Takahashi

2019 ◽  
Vol 14 (3) ◽  
Author(s):  
Brundaban Patro ◽  
K. Kiran Kumar ◽  
D. Jaya Krishna

Abstract In the present paper, a variable gas properties Eulerian model is employed to model the gas-solid heat transfer in a three-dimensional horizontal pipe, subjected to an adiabatic wall. The numerical model has been validated with the benchmark experimental data and other theoretical results available in the literature, and found satisfactory agreements. Moreover, the numerical heat transfer results considering the variable gas properties (i. e. density, dynamic viscosity, thermal conductivity, and specific heat) and constant gas properties are compared. It is noticed that the variable gas properties significantly affect the heat transfer, when compared to the constant gas properties. Therefore, the consideration of constant gas properties for the prediction of heat transfer may not be suitable in gas-solid flows, subjected to an adiabatic wall. Moreover, the temperature profiles, solid volume fraction profiles, and gas-solid Nusselt number are discussed. Finally, the pressure drop prediction with respect to the solid loading ratio is studied, and found that the pressure drop slightly decreases with increasing the solid loading ratio.


Author(s):  
Il Woong Park ◽  
Maria Fernandino ◽  
Carlos Alberto Dorao

Two-phase flow instabilities have been studied during the past decades. Pressure drop oscillation (PDO) shows a relatively larger amplitude oscillation compared with other instabilities. This oscillation typically occurs when the system has compressible volume and operates in a negative slope region of the pressure drop versus flow rate curve. The characteristics of the PDO has been studied experimentally and theoretically. Even though research has been performed for identifying the characteristics of the PDO, how the PDO affects the heat transfer coefficient (HTC) remain unclear. In this study, the heat transfer coefficient is experimentally studied during pressure drop oscillation. The experiment is conducted with a heated horizontal tube with 5 mm inner diameter and 2.0 meters in length, and the R-134a is used a working fluid. For the cases studied, no significant effect of the PDO on the average heat transfer coefficient was observed.


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