Hybrid Dynamic Surrogate Modelling for a Once-Through Steam Generator

Hybrid Dynamic Surrogate Modelling for a Once-Through Steam GeneratorFour surrogate modelling techniques are compared in the context of modelling once-through steam generators (OTSGs) for offshore combined cycle gas turbines (GTCCs): Linear and polynomial regression, Gaussian process regression and neural networks for regression. Both fully data-driven models and hybrid models based on residual modelling are explored. We find that speed-ups on the order of 10k are achievable while keeping root mean squared error at less than 1%. Our work demonstrates the feasibility of developing OTSG surrogate models suitable for real-time operational optimization in a digital twin context. This may accelerate the adoption of GTCCs in offshore industry and potentially contribute towards a 25% reduction in emissions from oil & gas platforms.acceptedVersio

Achieving 50% weight reduction of offshore steam bottoming cycles

Adding a bottoming cycle to the gas turbines powering offshore oil and gas production plants allows additional power to be produced from recovered excess heat. Hence, the power demand of the platform can be met by burning less natural gas, and the CO2 emissions reduced by up to 25%. However, the weight of the current bottoming cycles must come down to enable widespread implementation. This work presents a thorough weight minimization of a steam bottoming cycle utilizing gas turbine exhaust heat. Unconventional, but feasible designs of heat exchangers, ductwork and structural components are considered along with materials switching. Overall weight reductions of 38% and 52% were achieved for a 16 MW and a 12 MW offshore bottoming cycle respectively when compared to a 16 MW reference system. Key factors in achieving the weight reduction were the use of small steam generator tubes with an inner diameter of only 10 mm, improved condenser design and the use of aluminium structural framework replacing steel. By more than halving the weight of the bottoming cycle, it's implementation potential on offshore platforms has been greatly improved and can move the oil and gas industry towards significantly reduced CO2 emissions.publishedVersio

Design optimization of compact gas turbine and steam combined cycles for combined heat and power production in a FPSO system–A case study

This case study aims to cover a wide range of relevant aspects related to combined cycle design, mechanical integrity and operational reliability for cogeneration of heat and power in FPSO systems. The methods consist of combined optimization of combined cycle thermodynamic design and geometry of steam generator; vibration analysis for flow induced vibrations; and thermal stress estimation of casings during cold start-stop scenarios. Challenges and opportunities for reliable water treatment systems are explored. The results show that small tubes, a compact tube bundle and a low condensation temperature reduces the once-trough steam generator (OTSG) weight. The vibrations numerical simulations in this work support the standard recommendations of using 35 times tube OD as upper limit for the unsupported tube length, which could be used as a reasonable design criterion. Thermal stresses analysis indicates that the design of beam arrangement, location, and stiffness of beams has a major impact on thermal stresses, and can be optimized to different plate thicknesses in order to avoid fatigue damage. Focus should be on reducing leaks of deaerator, steam turbine and condenser. It is recommended to add Na sensors after condenser and investigating the use of Electrodeionization (EDI) technology for make-up water production from seawater.publishedVersio

Low carbon power generation for offshore oil and gas production

Emission reductions in power generation for offshore oil and gas activities are key in order to reach climate targets in regions with this industry. This study presents a review of both established and immature low carbon power generation concepts, an analysis of their potential for greenhouse gas (GHG) emission reduction, and an evaluation of their offshore applicability. The potential for GHG emission reduction is quantified by estimating CO2 equivalent intensity for implementation on the Norwegian Continental Shelf. The offshore applicability is evaluated with emphasis on weight, infrastructure requirements, process heat availability, technical maturity, as well as health, safety, and environment (HSE). It is shown that power from shore is the only technically mature concept with potential for very high emission reductions (>95 %, provided that low GHG electric power is available). There are several alternative concepts under development that also can give significant emission reductions (>70 %), including fuel switching, CO2 capture and storage, and renewable power combined with energy storage. Combined cycle gas turbines and offshore wind power combined with gas turbines are technically mature and can achieve partial emission reductions (around 15–50 %, with the assumed system configurations). Other concepts offering partial emission reductions are under development, but do not show clear advantages over those already mentioned. It is pointed out that, to enable reaching the net zero emission targets, only efficiency improvements and power from shore are not enough, and there is a need to develop additional low emission technologies not yet on the market. The present study has compiled a large database of specifications for assessing low carbon power production concepts and proposes a methodology that is valuable in screening a large number of commercial and immature technologies.publishedVersio

Annex 15- Excess Heat: Summary of Meeting May 26th -May 27th and Way Forward

Abstract heading Annex 15- Excess Heat sorts under the IETS (Industrial Energy –Related Technologies and Systems). It is an implementing agreement established under the auspices of the IEA. The goal is to show that there is potential for waste heat utilization in the world. This report summarizes a few key points from the Annex 15 meeting in Lisbon, on May 26-27th and describes remaining work to be performed to complete Phase I of the Annex and the effort required to participate in Phase II of Annex 15.publishedVersio

Industrial Excess Heat Recovery - Status of the Norwegian Industry - Report within the framework of SINTEF's participation in IEA IETS Annex XV

This report is a deliverable to International Energy Agency ‐ Industry‐related Energy and Technology Systems (IEA IETS) Annex XV, focusing of industrial excess heat recovery. SINTEF Energy Research represents Norway in the Annex XV. The associated deliverables for the subtasks defined in the Annex XV Task 2 are summarized in this report. Subtask 1: Evaluation and inventory of excess heat levels Deliverable (Del) 1 ‐ Inventory of projects implemented for excess heat utilization in Norwegian industry Subtask 2: Methodology for the practical inventory Del.2 ‐ Proposal for a standardized survey method for excess heat inventory from industrial plants Subtask 3: Possible policy instruments and the influence on future use of excess heat Del.3 ‐ Matrix of available policy instruments with their effects Subtask 4 Technology development (contributions from R&D) Del.4 ‐ Recent results from research projects in the field of novel hightemperature heat pumps.publishedVersio

Industrial Excess Heat Recovery – Status of the Norwegian Industry

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Industrial Excess Heat Recovery – Status of the Norwegian Industry

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Wet expansion steam cycles for offshore industry

Urokinazni plazminogenski aktivator izvanstanična je proteaza koja sudjeluje u procesima razgradnje izvanstaničnog matriksa te može biti regulirana sustavom koji upravlja procesima epitelno-mezenhimske tranzicije. Procesi tranzicije često su regulirani putem TGFβ koji potiče ekspresiju gena tipičnih za mezenhimski fenotip, kao i migraciju. Cilj ovog istraživanja bio je utvrditi ulogu signalnog puta TGFβ u regulaciji sustava urokinaznog plazminogenskog aktivatora (uPA) i u mehanizmu djelovanja natrijevog salicilata na promjenu aktivnosti uPA kod nekoliko staničnih linija tumora. Uzgojene su stanice glioblastoma transficirane plazmidom sa sekvencom za TGFβ koje su imale veću aktivnost urokinaze u odnosu na roditeljske, brže su migrirale, ali su im stopa proliferacije i morfologija bile nepromijenjene. Analizom proteina nije detektirano povećanje ekspresije urokinaze, ali jest njenog inhibitora. Inhibicija receptora TGFβ smanjila je bazalnu aktivnost urokinaze glioblastomskih stanica, kao i aktivnost induciranu obradom natrijevim salicilatom. Kod drugih dviju staničnih linija inhibicija puta TGFβ nije smanjila aktivnost urokinaze. Zaključeno je da TGFβ može sudjelovati u regulaciji sustava urokinaze, na stanično specifičan način.Urokinase plasminogen activator is an extracellular protease involved in the processes of extracellular matrix remodelling which is supposed to be regulated by mechanism of epithelial-mesenchymal transition. These processes can be regulated by TGFβ which induce expression of genes typical for mesenchymal phenotype, as well as migration. The aim of this investigation was to establish the role of TGFβ signalling pathway in urokinase plasminogen activator (uPA) system regulation and in the mechanism of uPA activity changes caused by sodium salicylate in several tumour cell lines. We analysed glioblastoma cells transfected with plasmid containing TGFβ sequence and found higher urokinase activity and increased migration in comparison with parental cells, but proliferation rate and morphology were unchanged. Protein analysis did not reveal increase in urokinase expression but plasminogen inhibitor expression was upregulated. TGFβ receptor inhibition decreased the basal urokinase activity in glioblastoma cells, as well as activity induced by sodium salicylate treatment. In two other cell lines TGFβ signalling inhibition did not decrease urokinase activity. It was concluded that TGFβ can participate in urokinase system regulation, but in a cell specific way