The appliance of data science to hybridisation
Stefan Goranov, Program Manager – Hybridisation at engine designer WinGD discusses the progress of the company’s hybridisation programme.
Hybridisation in the marine sector is rapidly evolving, but as received wisdom has it, today’s marine grade lithium-ion batteries have relatively low energy density. This leads to the significantly high weight and volume to store enough energy for the high-power requirements for propulsion of larger merchant marine ships. Hence, the limited wider applicability for deep-sea vessels. The most economical way ahead is to match the complete system topology and its operation strategy with concrete business objectives and the vessel’s mission. Different cargoes, equipment, and desired modes of operation have immense impact on the system architecture, and consequentially on the capital expenditures and operational costs.
Winterthur-based two-stroke engine designer WinGD plans to throw light on the commercial case for hybridisation in the deep-sea market, by introducing detailed use cases for two separate vessel types “by early 2020”, Stefan Goranov, Program Manager – Hybridisation told The Motorship in an interview in July.
“We are working on a feasibility study to quantify the benefits and the tradeoffs between a conventional and hybrid propulsion system with WinGD two-stroke main engines.”
The programme goes far beyond the application of power takeoff (PTO)/power take in (PTI) solutions to two-stroke engines. WinGD already offers such solutions to customers, and the technology has been installed on multiple vessels, including shuttle tankers featuring twin propulsion 520mm-bore XDF engines and dynamic positioning system (DPS).
The goal of the programme is to deliver solutions that arrange other technologies around the main propulsion engine and enhance the overall system performance through efficient integration.
Goranov stressed the project from WinGD’s perspective was primarily focused on deep-sea vessels’ main propulsion engines.
“Using battery storage enables us to run the engine at its most efficient operational point in terms of fuel consumption. Other modes being foreseen are power boost, peak shaving, electrical engine start and manoeuvring for zero-emission propulsion in port, and provision of spinning reserve for black-out prevention. Downsizing the main engine might also be possible.”
Goranov added that there were potential advantages also in terms of reducing auxiliary engines’ power requirements, which might interest ship owners and impact the financial case of such models, by permitting the number of auxiliary engines to be rationalised, while the optimisation of auxiliary engine operation would lead to reduced fuel consumption, maintenance costs and longer service lives.
The potential advantages would vary depending on the type of vessel, its operational profiles and would be vessel-specific, taking into account route specific and detailed system-specific energy consumption data.
The regulatory environment is helping to drive interest in hybridisation. The implementation of EEDI Phase 3 for a number of ship types, including container ships, general cargo ships, gas carriers and LNG Carriers is likely to be brought forward to 2022 (from 2025). Meanwhile, industry observers have noted that comparatively few oil tanker designs are currently able to comply with Phase 3 requirements.
Goranov noted that hybridisation offered potential advantages for oil tankers, which could potentially help them meet upcoming EEDI requirements. Ro-Ro ships also represented a very interesting vessel class, Goranov added.
Technical use case
One of the first deliverables for the program will be technical use cases to allow WinGD to demonstrate the value of such a system. “They will provide a detailed breakdown of the gains and trade-offs, the specific data and the savings”, Goranov said.
The use cases under development compare a conventional propulsion setup with WinGD engines with a battery hybrid solution operating in conjunction with WinGD engines. “We plan to release the cases early 2020, to obtain market feedback for the proposed solutions, align our activities accordingly, and maximise the value to our customers”.
This would require highly detailed analyses of energy consumption profiles. “Once the system requirements and desired features are defined, we are looking deep into relevant power request profiles from both the propeller and ship’s grid. We then feed the prepared data into topology sizing and control optimisation algorithms, in order to iterate alternatives, derive the boundary conditions and recommend the appropriate size of system’s components and strategies for energy management.”
Meanwhile, a separate deliverable from the development project is planned in mid-term, a platform with embedded high-fidelity simulation models for use by system integrators and ship designers, covering hydrodynamics such as hull design and propellers, as well as propulsion packages.
“Our goal is to maximise the efficiency of the system as a whole through efficient integration, determining the optimum topology, tuning, and operation strategy. The two-stroke engine is at the heart of such a system”, Goranov said.
Furthermore, WinGD could investigate the impact of different propeller designs, hull designs, friction increase due to hull fouling. By means of our approach, the engine designer might be able to help ship designers to quantify (in terms of fuel consumption) the improvements they make on the ship hull or propeller design.
All the above is only possible with high-fidelity simulation models and a state-of-the art digital toolchain. WinGD’s way to plausibly virtualise the development environment is by deploying a modular full-system simulation platform, containing transient-capable engine- and electromechanical components’ models.
Taking the complete system into consideration is imperative for determining the best fitted propulsion system for a given ship design. We also aim to enable creation of multiple power request profiles for a given sea route, depending on desired ship speed and sea weather. Hence the best performing control strategies can be identified.
“Our intention is to have a propulsion system that fits like a glove for a given ship.”
The Motorship notes that this would also contribute towards IMO-level discussions about the minimum propulsion power required for tankers or bulk carriers to maintain manoeuvrability in adverse conditions.
The research project is being led from WinGD, Winterthur and the research is being undertaken in collaboration with a number of Swiss research institutions, following WinGD’s model of sustaining advanced engineering research networks. WinGD is collaborating with equipment suppliers, ship designer and research institutions in China, drawing on existing relationships with affiliates of CSSC.
WinGD is also seeking to work together with battery suppliers and system integrators in the project, as well as to strengthen in-house expertise in the area. “Our role as an engine designer is to recommend certain integration strategies with our engines and certain solutions, but we have no intention of moving into the battery cell supply business”, Goranov said.
“We are also building up hardware-in-the-loop test systems in Winterthur in order to permit fine-tuning of the hybrid model in a “semi-physical” set-up.”
As a measure of WinGD’s commitment to the hybridisation project, Goranov noted that the second test engine in Winterthur will also be upgraded to allow the testing and validation of the hybrid system.
Goranov has particular expertise in managing these projects, having recently led WinGD’s next generation engine control development, WiCE. Prior to joining WinGD, Goranov began his career at sea, culminating in a role as chief electrical engineer aboard a cruise ship. He then moved to Wartsila, where he worked in Automation and Control.
“The two issues we face in terms of electrifying a two-stroke propulsion system are that the power needs are high and the upfront cost, when the complete energy system is not optimised, is quite significant.” Goranov noted that rapid progress in battery production costs had seen the cost of battery systems fall over the last ten years to a remarkable extent.
There are some bottlenecks in the battery sector. “When we look at the cost structure of a battery package, we struggle to see much scope for prices to keep substantially falling, if the technologies behind do not sensibly evolve”, although efficiencies from manufacturing at scale may offset some of the pressures from raw material input prices.
A number of battery suppliers have products that meet the requirements and each solution has its own relative advantages. Chemistry, energy density, charging and discharging (C) rates, and other considerations all need to be taken into account for “fit for purpose” solutions, he concluded.
LATEST PRESS RELEASES
Date: March - April 2019 Customer Name: UK Cruise Operator AtZ Contact: Project Engineer Clive ... Read more
When a customer in Singapore contacted Vickers Oils needing urgent help, we were able to deliver des... Read more
Trinity House, a UK based charity dedicated to safeguarding shipping and seafarers since 1514, has b... Read more
Stolt Tankers and DESMI Ocean Guard sign Frame Agreement for the Supply of CompactClean Ballast Wate... Read more
DESMI Ocean Guard’s CompactClean Ballast Water Management System receives amended US Coast Guard Typ... Read more
DESMI has gained a solid reputation over the years for selecting exactly the right materials for its... Read more