Numerical study of heat transfer characteristics in BOG heat exchanger. (December 2016)

• Record Type: Journal Article
• Authors: Yan, Yan; Pfotenhauer, John M.; Miller, Franklin; Ni, Zhonghua; Zhi, Xiaoqin
• Is Part Of: Cryogenics. Volume 80:Part 1(2016)
• Page Start: 97
• Page End: 107
• Publication Date: 2016-12
• Subjects: BOG heat exchanger -- Heat transfer -- CFD method -- Numerical simulation -- Thermal response; Low temperature engineering -- Periodicals; Low temperature research -- Periodicals; 536.56
• DOI: 10.1016/j.cryogenics.2016.09.011
• Languages: English
• ISSNs: 0011-2275

Abstract

Highlights: Thermal condition in a BOG heat exchanger has been performed by CFD simulations. Simulation has been validated by the design specification from engineering data. Thermal effects on the local structure and shell-side mass flowrate were studied. There exists a cold region in the bottom-right corner of the heat exchanger. The ratio of heat flux grow to the mass flow interval is greater at lower mass flow. Abstract: In this study, a numerical study of turbulent flow and the heat transfer process in a boil-off liquefied natural gas (BOG) heat exchanger was performed. Finite volume computational fluid dynamics and the k – ω based shear stress transport model were applied to simulate thermal flow of BOG and ethylene glycol in a full-sized 3D tubular heat exchanger. The simulation model has been validated and compared with the engineering specification data from its supplier. In order to investigate thermal characteristics of the heat exchanger, velocity, temperature, heat flux and thermal response were studied under different mass flowrates in the shell-side. The shell-side flow pattern is mostly determined by viscous forces, which lead to a small velocity and low temperature buffer area in the bottom-right corner of the heat exchanger. Changing the shell-side mass flowrate could result in different distributions of the shell-side flow. However, the distribution in the BOG will remain in a relatively stable pattern. Heat flux increases along with the shell-side mass flowrate, but the increase is not linear. The ratio of increased heat flux to the mass flow interval is superior at lower mass flow conditions, and the threshold mass flow for stable working conditions is defined as greater than 0.41 kg/s.