Marine Waste Heat Recovery System

Abstract

Abstract The usage of wasted energy in human‐made processes to reduce the need of more energy coming from raw materials has been recorded since the Industrial Revolution. Shipping, being the most energy‐efficient means of transportation, commonly uses waste heat recovery systems on board to further increase its operative efficiency. Waste heat is used to produce steam or electricity which is consumed on board. As main engines' thermal efficiencies start to plateau because they are close to the theoretical maximum efficiencies and as emission regulation becomes more stringent, it is important to look for alternative usages, processes, and designs of waste heat recovery systems. The purpose of this article is to give the reader a broad idea of how the energy on board a ship can be reutilized in order to increase the ship's fuel consumption, hence reducing the emission of noxious gases (e.g., CO 2 and NO x ) into the environment. Also, it explores traditional and alterative waste heat recovery processes, usages, and systems, which are installed on board nowadays or could be in the near future. This work focuses mainly on the use of the ship's prime mover waste heat, but this does not mean that the technologies and approaches described in this article cannot be applied to other systems such as auxiliary engines or electrical generators on board. This article starts with the history of waste recovery systems and then moves for a brief description of different marine CO 2 ‐mitigating strategies and where the available waste heat can be found on board. It then covers what a thermal machine is and how it can be used to produce heating, cooling, and mechanical and electrical power through different thermodynamic and electrical processes. Finally, it concludes that traditional and alternative waste heat recovery systems installed on board are important players in achieving more efficient shipping.