Cryogenic pipe flow simulation for liquid nitrogen under steady state conditions

Cryogenics, a thermodynamics study on fluids at temperatures less than 120 K, has many applications in a variety of fields. However, the problem of the high temperature difference between ambient air and temperature of the cryogenic liquid in the transfer line, is...

Full description

Saved in:

Bibliographic Details
Main Author:	Lim, Chong Lye
Format:	Thesis
Language:	English
Published:	2019
Subjects:	Thermodynamics Low temperature engineering
Online Access:	http://psasir.upm.edu.my/id/eprint/85507/1/FK%202020%2017%20-%20ir.pdf
Tags:	Add Tag No Tags, Be the first to tag this record!

id	my-upm-ir.85507
record_format	uketd_dc
spelling	my-upm-ir.855072021-12-14T08:30:25Z Cryogenic pipe flow simulation for liquid nitrogen under steady state conditions 2019-11 Lim, Chong Lye Cryogenics, a thermodynamics study on fluids at temperatures less than 120 K, has many applications in a variety of fields. However, the problem of the high temperature difference between ambient air and temperature of the cryogenic liquid in the transfer line, is a limiting factor. Thus, temperature leakage for heat gain in the transfer line is of utmost concern. Experimental works can be rather costly and dedicated Computational Fluid Dynamics (CFD) for cryogenics are limited and require many supporting peripherals. The aim of this study is to simulate velocity and temperature profiles of line liquid nitrogen using common CFD package (FLUENT) for fast tracking of flow characteristics of liquid nitrogen (LN2). In addition, this study numerically investigates the thermal and hydrodynamic performance of the Vacuum Insulated Pipe (VIP) and Polyurethane (PU) foam insulations by using an experimentally validated finite volume method (FVM) model. The continuum, momentum and energy equations are solved in the cryogenic temperature range. The LN2 is assumed as a homogenous liquid and incompressible at 4 bar operating pressure. The geometry and physics of the liquid nitrogen flow are axisymmetric for the horizontal transfer line. The simulation model in this study is solved using the commercially available CFD computational code. This study numerically investigates single phase heat transfer of LN2 pipe flow for the inlet volume flow range of 250 to 2000 litre per hour (LPH) at 4 bar operating pressure and 300 K ambient temperature under steady state conditions. A three-dimensional LN2 pipe flow with k-epsilon (k-ε) turbulence simulation model has been conducted using CFD ANSYS FLUENT. Both insulator and jacket pipe layers are created as shell layers where the shell conduction model predicts the thermal resistance incurred in the presence of multilayers. The axisymmetric velocity results from the investigation are within the range of 0.44 to 3.39 m/s for inlet volume flow rates of 250 to 2000 LPH. The temperature distributions resulting from the LN2 pipe flow simulation with VIP are within the range of 77.0 K to 82.1 K for inlet volume flow rates of 250 to 2000 LPH. The wall heat flux for VIP used for the present study shows the relatively high heat transfer at the wall as compared to PU foam. In conclusion, the simulation model of LN2 pipe flow successfully developed and shown an optimum combination of multilayer insulation (MLI) with 20 layers and high vacuum provides the wall heat flux less than 1 W/m2. The simulation results provide useful insights on the flow field of the cryogenic transfer line. Thermodynamics Low temperature engineering 2019-11 Thesis http://psasir.upm.edu.my/id/eprint/85507/ http://psasir.upm.edu.my/id/eprint/85507/1/FK%202020%2017%20-%20ir.pdf text en public doctoral Universiti Putra Malaysia Thermodynamics Low temperature engineering Adam, Nor Mariah
institution	Universiti Putra Malaysia
collection	PSAS Institutional Repository
language	English
advisor	Adam, Nor Mariah
topic	Thermodynamics Low temperature engineering
spellingShingle	Thermodynamics Low temperature engineering Lim, Chong Lye Cryogenic pipe flow simulation for liquid nitrogen under steady state conditions
description	Cryogenics, a thermodynamics study on fluids at temperatures less than 120 K, has many applications in a variety of fields. However, the problem of the high temperature difference between ambient air and temperature of the cryogenic liquid in the transfer line, is a limiting factor. Thus, temperature leakage for heat gain in the transfer line is of utmost concern. Experimental works can be rather costly and dedicated Computational Fluid Dynamics (CFD) for cryogenics are limited and require many supporting peripherals. The aim of this study is to simulate velocity and temperature profiles of line liquid nitrogen using common CFD package (FLUENT) for fast tracking of flow characteristics of liquid nitrogen (LN2). In addition, this study numerically investigates the thermal and hydrodynamic performance of the Vacuum Insulated Pipe (VIP) and Polyurethane (PU) foam insulations by using an experimentally validated finite volume method (FVM) model. The continuum, momentum and energy equations are solved in the cryogenic temperature range. The LN2 is assumed as a homogenous liquid and incompressible at 4 bar operating pressure. The geometry and physics of the liquid nitrogen flow are axisymmetric for the horizontal transfer line. The simulation model in this study is solved using the commercially available CFD computational code. This study numerically investigates single phase heat transfer of LN2 pipe flow for the inlet volume flow range of 250 to 2000 litre per hour (LPH) at 4 bar operating pressure and 300 K ambient temperature under steady state conditions. A three-dimensional LN2 pipe flow with k-epsilon (k-ε) turbulence simulation model has been conducted using CFD ANSYS FLUENT. Both insulator and jacket pipe layers are created as shell layers where the shell conduction model predicts the thermal resistance incurred in the presence of multilayers. The axisymmetric velocity results from the investigation are within the range of 0.44 to 3.39 m/s for inlet volume flow rates of 250 to 2000 LPH. The temperature distributions resulting from the LN2 pipe flow simulation with VIP are within the range of 77.0 K to 82.1 K for inlet volume flow rates of 250 to 2000 LPH. The wall heat flux for VIP used for the present study shows the relatively high heat transfer at the wall as compared to PU foam. In conclusion, the simulation model of LN2 pipe flow successfully developed and shown an optimum combination of multilayer insulation (MLI) with 20 layers and high vacuum provides the wall heat flux less than 1 W/m2. The simulation results provide useful insights on the flow field of the cryogenic transfer line.
format	Thesis
qualification_level	Doctorate
author	Lim, Chong Lye
author_facet	Lim, Chong Lye
author_sort	Lim, Chong Lye
title	Cryogenic pipe flow simulation for liquid nitrogen under steady state conditions
title_short	Cryogenic pipe flow simulation for liquid nitrogen under steady state conditions
title_full	Cryogenic pipe flow simulation for liquid nitrogen under steady state conditions
title_fullStr	Cryogenic pipe flow simulation for liquid nitrogen under steady state conditions
title_full_unstemmed	Cryogenic pipe flow simulation for liquid nitrogen under steady state conditions
title_sort	cryogenic pipe flow simulation for liquid nitrogen under steady state conditions
granting_institution	Universiti Putra Malaysia
publishDate	2019
url	http://psasir.upm.edu.my/id/eprint/85507/1/FK%202020%2017%20-%20ir.pdf
_version_	1747813552404561920

Cryogenic pipe flow simulation for liquid nitrogen under steady state conditions

Similar Items