The Study of Working Fluid Selection for LNG Cold Power Generation Process

• Main Authors: Chang, Shin yun, 張新運
• Other Authors: Su, Yuan Yuan
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/27760448868461033008

碩士 === 國立臺北科技大學 === 化學工程系碩士班 === 92 === This study employed PRO-II process simulation software with the operating data from the existing Rankine Cycle process in Yuan An LNG Receiving Terminal to establish the basic simulation model for power generation driven by LNG cold power. By fixing system conditions of LNG inlet and outlet streams, seawater temperature and available temperature difference, the vaporizing temperature and condensing pressure of working fluid, five working fluids such as propylene, ethylene, R12, R13 and R22 in place of propane was adopted to perform overall system thermal efficiency and power generating beneficial analysis. It was found that there is no a simple rule of thumb to determine the most appropriate working fluid for maximum power generation profit by any one condition of the higher system thermal efficiency, the larger LNG/working fluid heat exchanged rate, higher Rankine Cycle circulation pressure or higher expander pressure difference. However, after grabing the vaporizing and condensing temperature of working fluid in Rankine Cycle process from P-T diagram, we constructed an enclosed area, representing net work of unit mass, on T-S diagram by following Rankine cycle. It indicated that the product of net work of unit mass and mass flow rate of selected working fluid fairly matches the simulation result obtained by PRO-II. This simple and quick approach can be used to determine the power generation efficiency for any considered working fluid.