Expansion of organic Rankine cycle working fluid in a cylinder of a low-speed two-stroke ship engine
Journal article, 2017

Electricity and power produced from waste heat is particularly relevant in shipping because fuel expenses constitute the majority of the cost of operating the ships; however, the cost-benefit aspect limits the widespread implementation of waste heat recovery power units on ships. This paper presents the thermodynamic analysis of a concept that aims at reducing the cost of an organic Rankine cycle unit by using one of the cylinders in a large diesel engine as expansion device. Numerical models were used to optimise the process parameters and thereby determine the power potential for this concept. The evaluation of 104 working fluids points to cyclopropane, R245fa and R1234ze(z) as the most promising. The results suggest that the power produced by the organic Rankine cycle cylinder is at least equivalent to that of the cylinders operating with the diesel process. This enables potential fuel savings and emissions reductions of about 8.3% in the studied scenario.

Piston expander

Novel configuration

Waste heat recovery

Organic Rankine cycle

Marine diesel engine


Ulrik Larsen

Chalmers, Shipping and Marine Technology, Maritime Environmental Sciences

Jorrit Wronski

IPU, Denmark

J. G. Andreasen

Technical University of Denmark (DTU)

Francesco Baldi

Chalmers, Shipping and Marine Technology, Maritime Environmental Sciences

L. Pierobon

Technical University of Denmark (DTU)


0360-5442 (ISSN)

Vol. 119 1212-1220

Driving Forces

Sustainable development

Areas of Advance



Subject Categories

Energy Engineering

Vehicle Engineering



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