In seeking to fulfill its mission, the International Maritime Organization (IMO) is dependent on the capabilities of its Member States. While flag States remain primarily responsible for ensuring compliance of their registered vessels with instruments adopted under that United Nations specialized agency's aegis, coastal States also play a competing but complementary role in the balance of jurisdiction over ships. In particular, the right to regulate the vessel's intent on visiting the port, or its presence therein, is often relied upon to account for the limitations of flag State enforcement. The capacity to act as a port State under international law is the basis for certain implementation mechanisms stemming from treaty provisions on port state control, as well as for innovative practices of port States, either collectively or individually. This chapter provides the reader with an overview of the role of port State jurisdiction in IMO law and practice, and the challenges that can arise in the complex relationship between port States and the IMO.
The legal limbo that defines the maritime space over which the process of delimitation of the outer continental shelf is applied appears today as an eminently practical question that needs to be addressed. The institutional framework provided by UNCLOS, which establishes the existence of an internationalized space on the seabed - the area - seems limited to respond to a debate that confuses Geology with Law. This article focuses on the powers of the International Seabed Authority as an agency authorized to act on behalf of Mankind by exploring its weaknesses in its exercise of this mandate in the context of that process. By analyzing the conflict between the expansionist goals of States and the embodied principle that gives the Authority the assignment to act on behalf of Mankind in securing a space that, according to the text of the Convention, belongs to it, we conclude that there are apparent inconsistencies in the institutional framework created the Montego Bay Convention. In our exegesis of Part XI of the Convention, we work on the cogent force of that principle and raise questions about the legal legitimacy of the entire process, ie in the absence of a clear statement by the above-mentioned Authority. We conclude that the text of the Convention provides the possibility of a direct intervention by the Authority but that there are still no political conditions for such a possibility to be realised.
This article aims to present the most relevant practices of offshore oil contracting at an international level, in order to better understand the legal dynamics of the sector. The problem investigated deals with the terms of the legal relationship between the State and national and foreign public companies, as well as the relationship between States, with a view to the exploitation of shared offshore oil resources. This problem is current, taking into account both the fact that oil is a scarce resource, as well as the fact that its offshore exploration is particularly complex and risky. This article presents, in a non-exhaustive way, some examples of practices that illustrate contractual trends that have already crystallized. The approach to its content is made from an international law perspective, focused on the transnational challenges posed to States and operators. It is concluded that the sector is characterized by a huge variety of practices, which reveals an ability of operators to adapt to the characteristics of the concrete challenges of an offshore exploration project. It also shows the political and economic particularities of the States involved in the process.
Ship-source pollution represents a threat to the environment, regardless of where it occurs. The European Union has been developing standards that aim to counter accidental, operational and intentional pollution in the waters under its member-state's jurisdiction. However, and precisely because marine pollution knows no boundaries, the EU is not coy in contemplating what ships do beyond waters under the sovereignty of its member states. This article analyzes the international legality of EU claims to port state jurisdiction over ship-source pollution. It demonstrates that port state jurisdiction is today not only a means to ensure compliance with international standards but also a means to unilaterally enforce more stringent environmental standards.
This paper discusses the governance of port classification through the lens of multi-level governance theory, with a particular focus on the Port of Aalborg and the issue of classification of Limfjord waters, in Denmark. The study identifies a conflict in which national governmental decisions regarding the classification of navigable waterways obstruct the port's access to funding opportunities. Despite the port's autonomous operational capacity, national control over waterway classification and port typology shows a nested governance dynamic, thereby highlighting the intricacies of the European Union's subsidiarity principle. This paper argues that the case illustrates how the classification of inland waterways, although ostensibly legal, is intrinsically political and subject to national interests. The Danish government's refusal to designate the Limfjord as a navigable waterway potentially hinders regional development and impedes the EU's policy objectives for intermodality. Methodologically, the research synthesizes desk-based analysis with key-informant interviews to examine the legal, political, and geographical dimensions of this issue. The findings contribute to multi-level governance theory by describing the case as a hybrid model that integrates both nested and polycentric elements, thereby enriching the debate on governance complexities within the European context.
A numerical study on effects of the injection direction of the pilot diesel fuel on combustion and emissions under two-stroke dual-fuel marine engine-like conditions is presented in this paper. It is found that the injection direction of the pilot fuel has significant effects on the methane start of combustion as well as flame propagation direction which leads to different heat transfer trends to combustion chamber walls and flame- wall interaction. Furthermore, the injection direction of the pilot fuel changes the methane combustion intensity which leads to different trends for emission formation.
A computational fluid dynamics study of the scavenging process in a large two-stroke marine engine is presented in this work. Scavenging which is one of the key processes in the two-stroke marine engines, has a direct effect on fuel economy and emissions. This process is responsible for fresh air delivery, removing the combustion products from the cylinder, cooling the combustion chamber surfaces and providing a swirling flow for better air-fuel mixing. Therefore, having a better understanding of this process and the associated flow pattern is crucial. This is not achievable solely by experimental tests for large engines during engine operation due to the difficulties of measuring the flow field inside the cylinder. In this study, the axial and tangential velocities are compared and validated with the experimental results obtained from Particle Image Velocimetry (PIV) tests [1]. The simulations are conducted using both Unsteady Reynolds Averaged Navier Stokes (URANS) and Large Eddy Simulation (LES) turbulence models. We observe in general, there is a good agreement between the numerical and experimental results. The flow inside the cylinder is studied in different locations related to the bottom of the scavenging ports during the period with open exhaust valve. Moreover, the replacement of combustion products with fresh scavenge air is analysed. The effective flow angle is calculated for the air flow through the scavenging ports. It is found that the effective flow angle is different from the geometrical angle of the ports (20°). Results illustrate better performance of LES, especially in the prediction of the tangential velocity which is crucial for the simulation of an accurate swirl and air-fuel mixing inside the marine engines. LES predicts a uniform profile for the tangential velocity at the top of cylinder which is consistent with the experimental results while URANS predicts a solid body rotation.
The future fuel for marine engines is not yet decided. However, it is well-known that utilizing green alternative e- fuels is a big step in the way of decarbonization. Dual-fuel (DF) engines offer great fuel flexibility with possibility of using different green gaseous e-fuels like methane and ammonia. The ignition of the lean premixed gaseous fuel in a DF engine depends on the auto-ignition of the injected pilot diesel fuel. Therefore, a proper auto- ignition of the pilot diesel is important in these engines. In the present study, large eddy simulation is carried out to study the auto-ignition process of pilot diesel in premixed methane-diesel DF combustion in a constant volume combustion chamber. The entire DF combustion processes involving methane injection, methane/air mixing, pilot diesel injection, and ignition are simulated. The numerical model is validated against experimental data. The base case has a pilot diesel injector with 8 nozzle holes. The auto-ignition process in two other cases with 4 nozzle holes are investigated and compared with the base case. Considering same amount of pilot fuel, the injection rate is assumed to be double in one the cases, while in the other case, the injection duration is doubled. The results show that the ignition process in the case with 4 nozzle holes and double injection rate is incomplete due to flame impingement on the walls. However, a reduction of the nozzle hole numbers can improve diesel pilot ignition in the case with 4 nozzle holes and double injection duration. The higher fuel mass per orifice leads to an increased fuel concentration within the diesel pilot sprays and higher combustion rate than the base case. Furthermore, more confined spray envelope in the case with double injection duration leads to an increased reactivity and more efficient auto-ignition process than the case with double injection rate.
The offshore oilfields in the North Sea area are increasingly employed for projects beyond oil production, like carbon capture and storage (CCS). Still, the fossil fuel production from mature fields is significant. It has raised environmental concerns associated with discharging produced waters (PW) and drilling mud into the sea. These discharges, which may be highly saline and contain production chemicals, vary significantly in metals and particulate content. Due to density and release depth, the plume is assumed to sink towards the seafloor. Also, a single oilfield can input up to 7.5 tons of Ba, 675 kg of Fe, and 619 kg of P into the water column through PW. Therefore, this study investigates the impact of these discharges on seafloor sediments around two Danish oilfields, assesses the mobility of metals within these sediments, and evaluates the environmental status. PW samples were collected at the discharge outlets from the platforms. Sediment cores were taken near the two oil platforms and from control sites. Using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and an optimized BCR sequential extraction, we analyzed the composition and distribution of 24 elements in sediment samples. The results revealed significant differences in total extracted concentrations between sediments near the platforms and those from distant locations and stratigraphically older samples, with relevant levels of Br, Ba, and Sn near the platforms (averaged 14, 27, and 0.1 ppb, respectively). Sediment quality indices showed considerable enrichment and geo-accumulation of toxic metals, particularly at one of the platform sites. However, cumulative indices did not display significant pollution anomalies. Therefore, our findings suggest that oil extraction activities may increase the availability of toxic metals in nearby sediments, potentially impacting marine ecosystems.
Thermal energy storage, with its low energy storage cost and wide distribution in industrial processes, is an effective way to improve the operational flexibility of power plants. Due to colossal energy storage capacity and small deployment costs, this article proposes connecting district heating networks to combined cycle gas turbine (CCGT) plants as a thermal energy storage capacity, improving the flexibility of CCGTs. The main focus here is on developing an appropriate control strategy to effectively control the power-heat conversion, meet the heat and power demands of the connected network, and the operational flexibility of the plant. The major problem is that the intrinsic static and dynamic conversion relationship of power and heat in the CCGT and district heating network and the buildings are multi-factor interactive and unknown. Therefore, the CCGT bottom cycle and district heating network, and building models were built to obtain the power-heat conversion parameters and the dynamic model for control design. Then, the energy storage coefficient of 0.105 MW/kg/s is obtained through the model simulation instead of a complex thermodynamic calculation, corresponding to the 113.22 GJ energy storage capacity of the district heating network. Based on the obtained conversion rules, a new control strategy called ‘conversion coordinated control’ is designed and applied, using load signal decomposition and synergistic load response of flue gas mass flow rate and steam extraction valve. The simulation results show that the proposed method can promote a ramping load rate of 8.6 MW/min in the first 30 s with only 0.3 °C building temperature variation. The control strategy can effectively reduce the gap between the grid demand and CCGT power and ensure grid stability without compromising thermal users’ comfort.