Thermodynamic and Environmental Analysis of Low-Grade Waste Heat Recovery System for a Ship Power Plant

Abstract

Shipping is a growing sector in the global economy and its contributions to global greenhouse gas (GHG) emissions are expected to increase. Energy efficiency has always been an important factor to minimize GHG emissions. Waste heat recovery (WHR) systems can be used for both improving energy efficiency and reducing energy consumption and GHG emissions. Organic Rankine Cycles (ORC) systems are the most widely used technology for low temperature heat recovery from exhaust gases in the industrial applications. But this system is not widely used in ship applications. In this study thermodynamic performance criteria of ORC system for a container ship are developed and thermodynamic, environmental and economic effects of the system are analyzed. It can be achieved additionally 2% reduction for the ship fuel consumption by utilizing the ORC system.

Advanced Exergy Analysis of an Organic Rankine Cycle Waste Heat Recovery System of a Marine Power Plant

“…Beside the lever position as parameter, second parameter is chosen as organic fluid. With respect to the main engine data, 7 organic compound selected from previous works as cyclohexane [18], isohexane [28], R141b [29], R601 and R601a [30], R113 [9], lastly most frequently used R245fa [10,11,17,18,[28][29][30][31]. All of them were evaluated in EES software [32] with respect to working interval of temperature and pressure.…”

“…Cycle data could be found in Table 5 ANALYSIS By using information given in Table 5, real cycles are designed. Temperature of exhaust stack after economizer is fixed at 160 ℃ to avoid low temperature corrosion risk [30]. That restriction will give the highest possible waste heat harvesting opportunity.…”

Advanced Exergoeconomic Analysis of Organic Rankine Cycle Waste Heat Recovery System of a Marine Power Plant

“…VLCC ship data used in this study. Organic fluids are selected as working fluids for WHR ORC systems from previous works of R141B [15], R601 and R601A [48], R113 [12,[16][17], and R245FA analyzed in [15, 23-24, 48, 51-54]. They are selected considering their working temperatures, pressures and performances among other organic fluids [29] and are given in Table 3.…”

Advanced Exergoeconomic Analysis of Organic Rankine Cycle Waste Heat Recovery System of a Marine Power Plant

“…Thus, there is an already WHR system installed in the investigated ship. At the end of the exhaust boiler, before to be discharged to atmosphere, exhaust gases still have a relatively high temperature above Sulphur corrosion point (160℃) [48], thus a closed ORC system can be utilized. General information of investigated ship and main engine is in Table1 and the VLCC data at fully loaded condition for this study is given in Table 2 [29].…”