Design and performance evaluation of an Organic Rankine Cycle system exploiting the low grade waste heat of the main engines in a LNG carrier

Organic Rankine Cycle technology may represent an interesting way to exploit the low grade waste heat rejected by the ship power generating plant. A simple ORC cycle, a regenerative cycle and a two-stage cycle have been investigated to exploit the heat associated with the jacket water, lubricating oil and charge air cooling of the main engines in a real LNG carrier. The maximum net power output (820 kW) achieved by the two-stage ORC almost doubles the simple cycle and regenerative ones