Experimental Analysis of Hot Startup and Cold Startup of Bog Compressor at LNG Terminal
Bandita Samal1, Sanam Sarita Tripathy2
1M.Tech in Environmental Engineering GIFT Autonomous College
2Assiastant professor in Civil Engineering Department, GIFT Autonomous College
Abstract - Liquified Natural Gas (LNG) terminals are crucial for receiving, storing, and transferring natural gas in liquid form. A key component of these terminals is the Boil off Gas (BOG) compressor, which is used to manage the vaporized LNG during storage and transfer processes. The compressor's ability to start up efficiently is critical for maintaining smooth terminal operations, especially in managing boil-off gas (BOG), which occurs when LNG naturally vaporizes due to heat ingress into storage tanks. This study presents a detailed comparison between Hot and Cold Startup procedures for Boil-Off Gas (BOG) compressors at an LNG terminal. BOG compressors are crucial for managing vaporized LNG during storage and transfer, and their startup processes significantly impact system performance and efficiency. Hot Startup refers to initiating the compressor without achieving the cryogenic temperature when the system components are at operational temperatures and pressures while Cold Startup occurs after an idle period, by gradually cooling the line and compressor for operating system at lower pressures and temperatures.
The experimental analysis was carried out for hot startup and Cold startup which primarily focused on key parameters such as pressure, temperature, energy consumption, Flow rate, cost and system stability during both startup conditions. The results indicated that Hot Startup requires lower energy consumption and results in quicker stabilization but leads to system stress thereby damaging the internal machinery parts whereas the cold startup requires more time, higher energy input leading to concerns about gas loss and environmental impact.
The findings highlight the operational challenges and efficiency trade-offs associated with each startup type, the design modifications made in cold start type to cater to the needs of optimizing LNG terminal operations and enhancing overall system performance without compromising with economic losses.
Keywords: BOG compressor, Hot startup, Cold startup, LNG industry
