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The development of a sub-atmospheric two-phase thermosyphon natural gas preheater using a lumped capacitance model and comparison with experimental results / H. Matallah; W. Newton; D. James; I. Cameron; J. Sienz; S. Romocki; N.P. Lavery

Applied Thermal Engineering, Volume: 104, Pages: 767 - 778

Swansea University Author: Lavery, Nicholas

Abstract

The pre-heating of natural gas supplied to both domestic and industrial use is required to counteract the Joule–Thomson effect due to pressure reduction. Most existing pre-heaters are in the form of water bath heaters, where both the burner and exchanger are immersed in a closed water tank. These sy...

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Published in: Applied Thermal Engineering
ISSN: 1359-4311
Published: 2016
Online Access: Check full text

URI: https://cronfa.swan.ac.uk/Record/cronfa38093
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Abstract: The pre-heating of natural gas supplied to both domestic and industrial use is required to counteract the Joule–Thomson effect due to pressure reduction. Most existing pre-heaters are in the form of water bath heaters, where both the burner and exchanger are immersed in a closed water tank. These systems usually have a low efficiency, and as a result of thermal inertia have a long time lag to accommodate changes in Natural Gas (NG) mass flow rates.In this paper, the two-phase thermosyphon theory is implemented in a sub-atmospheric context to design and study a new preheating system in a transient fashion. This system is partially vacuumed (absolute pressure of 2 kPa) to lower the temperature operation range to reduce the required working fluid volume, hence reduce the required energy and improve the response time. The transient numerical model is based on a lumped capacitance method, and the full system is solved by using a fourth order Runge–Kutta method. The numerical model is validated through comparison with experimental results. Minimum efficiency of 68% has been achieved in some tests, whilst maximum efficiency of 80% in other tests.Simulations of the thermosyphon preheater system have been performed to analyse the effect of changing the working fluid volume and composition.
Keywords: Thermosyphon, Sub-atmospheric, Heat transfer, Joule–Thomson, Lumped-capacitance, Runge–Kutta
College: College of Engineering
Start Page: 767
End Page: 778