Enhancement of LNG Plant propane cycle through waste heat powered absorption cooling

CATEGORY: LNG – LIQUEFIED NATURAL GAS
Applied Thermal Engineering, Available online 21 April 2012, In Press, Accepted Manuscript — Note to users
Enhancement of LNG Plant propane cycle through waste heat powered absorption cooling
P. Rodgers a, A. Mortazavi b, V. Eveloy a, S. Al-Hashimi a, Y. Hwang b, R. Radermacher b
a The Petroleum Institute, Abu Dhabi, U.A.E
b Department of Mechanical Engineering, University of Maryland, College Park, MD, U.S.A
Abstract
In liquefied natural gas (LNG) plants utilizing sea water for process cooling, both the efficiency and production capacity of the propane cycle decrease with increasing sea water temperature.  Authors address this issue by studying several propane cycle enhancement approaches.  They require minimal modification of the existing plant configuration.
The approaches rely on the use of gas turbine waste heat powered water/lithium bromide absorption cooling to either (i) subcool propane after the propane cycle condenser, or (ii) reduce propane cycle condensing pressure through pre-cooling of condenser cooling water. Two alternative methods of pre-cooling condenser cooling water are considered nn the second approach, consisting of an open sea water loop, and a closed fresh water loop. In all cases, three candidate absorption chiller configurations are evaluated.  They are: single-effect, double-effect, and cascaded double- and single-effect chillers. The thermodynamic performance of each propane cycle enhancement scheme, integrated in an actual LNG plant in the Persian Gulf, is evaluated using actual plant operating data.
Full Text Source (Subscription or Fee): http://www.sciencedirect.com/science/article/pii/S1359431112002748