Comparative analysis of a bottoming transcritical ORC and a Kalina cycle for engine exhaust heat recovery. (1st January 2015)

• Record Type: Journal Article
• Authors: Yue, Chen; Han, Dong; Pu, Wenhao; He, Weifeng
• Is Part Of: Energy conversion and management. Volume 89(2015)
• Page Start: 764
• Page End: 774
• Publication Date: 2015-01-01
• Subjects: Internal combustion engine -- Organic Rankine cycle -- Waste heat recovery (WHR) -- Kalina cycle -- Thermal match; Direct energy conversion -- Periodicals; Energy storage -- Periodicals; Energy transfer -- Periodicals; Énergie -- Conversion directe -- Périodiques; Direct energy conversion; Periodicals; 621.3105
• DOI: 10.1016/j.enconman.2014.10.029
• Languages: English
• ISSNs: 0196-8904

Abstract

Highlights: Thermal performance comparison of two eligible bottoming cycles is investigated. Thermal match between the temperature profiles of working fluid and exhaust is considered. Influences of the various-temperature heat source on the two WHR cycles are studied. Bottoming transcritical ORC shows advantages at a certain ICE load. Suitable working conditions for both of the bottoming cycles are given. Abstract: A performance comparison of two types of bottoming cycles, including a Kalina cycle and a transcritical organic Rankine cycle (ORC) using working fluids with sliding-temperature boiling characteristics, is conducted in order to analyze energy saving of the sensible exhaust waste heat recovery (WHR) under various internal combustion engine (ICE) working conditions. Through quantitatively analyzing the relation between exhaust waste-heat behaviors and the ICE load of a commercial ICE, two bottoming subsystems models, including a transcritical ORC using some several Alkanes and a Kalina cycle using NH3 –H2 O as working fluids, are build under the same ICE various-temperature exhaust heat-source and air heat-sink conditions. Compared to Kalina cycle, the transcritical ORC shows prominent advantages on the overall thermal efficiency, low operation pressure and simple components configuration at the ICE load with exhaust temperature over 491 K. The optimal thermal performance of the transcritical ORC appears at the ICE load with the certain exhaust temperature of 569–618 K. However, thermodynamic performance of the bottoming transcritical ORC is worsened considerably at the ICE load with the exhaust temperature over or under the certain value. Moreover, the extremely high turbine expansion ratio requires a complex multi-stage turbine design and big turbine dimensions for the bottoming transcritical ORC using Alkanes-based working fluid.