This report, Waste heat recovery – use of absorption systems on ships, is a bachelor report at the education Bachelor of Technology Management and Marine Engineering at Aarhus School of Marine and Technical Engineering. The report is written in corporation with the Danish shipping company TORM A/S. Ideas and data supporting this project is taken from the ship, M/T TORM Ragnhild, during a 10 weeks stay in February-April 2013.
At TORM A/S recycling energy is a primary goal. Their priority is to reduce 20% CO2 emissions by 2020.
The report will describe the function of an absorption heat pump and analyse the possibility to reuse wasted heat, in terms of cooling water from the auxiliary engines via an absorption heat pump. The process involves the use of the high temperature cooling water to create a chilled water circuit. As a result, the water circuit will deliver the cooling capacity for the central AC system minimalizing the use of the installed refrigeration system. The implemented absorption process shows an 8% reduction in electrical power consumption, resulting in a total CO2 emission reduction by 1.2% for M/T TORM Ragnhild.
In addition to effectively reducing the utilization of the refrigeration compressor, there are other peripheral systems that will gain efficiency. The process requires a change in the current cooling water system that cannot exceed 33°C, otherwise the efficiency is being compromised. Therefore, the system would be most beneficial for a ship that sails in colder climates.
An audit between the current energy consumption versus the implementation of the new system will illustrate if the installation will be a beneficial investment. Such an installation is considered an attractive solution to not only decrease CO2 emissions but also to decrease the operating expenses.