ZHENIT - D 2.5: Collection of guidelines for future scaling up of technologies for onboard integration

The ZHENIT project aims at developing and validating some innovative technologies for waste heat valorization on board of vessels (i.e. adsorption chiller and desalination unit, ORC – heat pump with ejector, Isobaric Engine) and to support the main engine through innovative sails (i.e. rigid sails). Specifically, the proposed technologies for waste heat valorization are still at low TRL, ranging from TRL 4 up to TRL 5, while the innovative eSails are closer to a real marketability. Accordingly, at this stage it is important to define some preliminary guidelines for upscaling of these technologies in order to guide the future design efforts towards the future commercialization. At this stage, only energy efficiency and power density are considered, since techno-economic analyses will be provided by the end of the project. In order to evaluate the efficiency aspects, the simplified integration analysis on board of three reference vessels, namely, a large ferry ship, a cargo vessel, and a large fishing vessel was performed. This analysis mainly aimed at evaluating the impact of the integration of the technologies on board, with a focus on the possible fuel saving achievable by the different scenarios. This exercise considered, on one hand, the available waste heat on board of the reference vessels and the possible demands, in terms of heating, cooling, power and desalinated water. On the other hand, possible space constraints on board were analyzed. The starting point for each of the ZHENIT solutions was the energy efficiency and the power density evaluated either experimentally or numerically during the first phase of the project. The power density was only considered for the adsorption machine, being the one closer to a commercial level. The obtained data demonstrated that the ZHENIT solutions can be extremely attractive in application where the space available on board of the vessels does not represent a critical barrier. This is especially valid for large vessels, such as ferries, cruises and cargos. Moreover, in case of newly built vessels, the possibility of analyzing the integration on board since the designing phase could make this aspect easy to overcome. In vessels having these features, relevant fuel savings up to 7% of the overall consumption on board can be achieved. On the other hand, cases where the space constraints become critical, like the fishing vessels, are less attractive for the ZHENIT integration. Based on the above mentioned results, preliminary guidelines for upscaling foresee the further increase of the energy efficiency of each technology of at least 20% compared to the current development level. Moreover, a power density of 20 kW/m3 could be considered as a relevant target to meet. Similarly, a reduction the footprint of the eSails could be useful to increase the number of sails that can be installed in each vessel.