Blar i NTNU Open på forfatter "Nord, Lars O."
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Fluid selection and thermodynamic optimization of organic Rankine cycles for waste heat recovery applications
Agromayor, Roberto; Nord, Lars O. (Journal article; Peer reviewed, 2017)Organic Rankine cycles are effective to convert waste heat to power. One of the advantages and challenges of these cycles is that the most suitable working fluid and cycle configuration have to be selected for every ... -
Gas turbine exhaust gas heat recovery by organic Rankine cycles (ORC) for offshore combined heat and power applications - Energy and exergy analysis
Nami, Hossein; Ertesvåg, Ivar Ståle; Otero, Roberto Agromayor; Riboldi, Luca; Nord, Lars O. (Journal article; Peer reviewed, 2018)Effective heat and power supply to offshore installations leads to environmental benefits, but the efficiency is often limited by requirements and constraints connected to the offshore environment. An exergetic analysis ... -
Identifying operational requirements for flexible CCS plant in future energy systems
Mocholí Montañés, Rubén; Korpås, Magnus; Nord, Lars O.; Jaehnert, Stefan (Journal article; Peer reviewed, 2016)This paper aims at a discussion of operational requirements for thermal power plants with carbon capture and storage in terms of their interaction with the power system, in regions with high penetration of variable renewable ... -
An improved combined heat and power economic dispatch model for natural gas combined cycle power plants
Yu, Haiquan; Nord, Lars O.; Cong, Yu; Jianxin, Zhou; Fengqi, Si (Peer reviewed; Journal article, 2020)An increasing number of natural gas combined cycle (NGCC) plants are operated under combined heat and power mode. Therefore, a combined heat and power economic dispatch (CHPED) is the key to achieve the optimal utilization ... -
Innovative Hybrid Energy System for stable Power and Heat Supply in offshore oil & gas Installation (HES-OFF): System Design and Grid Stability
Riboldi, Luca; Alves, Erick Fernando; Pilarczyk, Marcin; Tedeschi, Elisabetta; Nord, Lars O. (Peer reviewed; Journal article, 2020)This paper presents an innovative hybrid energy system for stable power and heat supply in offshore oil & gas installations (HES-OFF). The hybrid concept integrates offshore wind power with gas turbines and a H2 energy ... -
Lifetime Assessment of Combined Cycles for Cogeneration of Power and Heat in Offshore Oil and Gas Installations
Riboldi, Luca; Nord, Lars O. (Journal article; Peer reviewed, 2017)The utilization of combined cycles for offshore cogeneration of power and heat is an attractive option to reduce the CO2 emissions directly related to the oil and gas sector. Main challenges for their efficient implementation ... -
Model predictive control for combined cycles integrated with CO2 capture plants
Rúa, Jairo; Nord, Lars O.; Hillestad, Magne (Peer reviewed; Journal article, 2021)Flexible thermal power plants integrated with CO2 capture systems can balance the intermittent power generation of renewable energy sources with low-carbon electricity. Among these power systems, natural gas combined cycles ... -
Offshore Power Plants Integrating a Wind Farm: Design Optimisation and Techno-Economic Assessment Based on Surrogate Modelling
Riboldi, Luca; Nord, Lars O. (Journal article; Peer reviewed, 2018)The attempt to reduce the environmental impact of the petroleum sector has been the driver for researching energy efficient solutions to supply energy offshore. An attractive option is to develop innovative energy systems ... -
One-Dimensional Annular Diffuser Model for Preliminary Turbomachinery Design
Agromayor, Roberto; Müller, Bernhard; Nord, Lars O. (Journal article; Peer reviewed, 2019)Annular diffusers are frequently used in turbomachinery applications to recover the discharge kinetic energy and increase the total-to-static isentropic efficiency. Despite its strong influence on turbomachinery performance, ... -
Optimal control of flexible natural gas combined cycles with stress monitoring: Linear vs nonlinear model predictive control
Rúa, Jairo; Nord, Lars O. (Peer reviewed; Journal article, 2020)In future energy markets, traditional thermal power plants are expected to cycle more to adapt their operation to the intermittent power generation of renewable energy sources. Gas turbine load ramps and stresses in ... -
Optimal Design of a Hybrid Energy System for the Supply of Clean and Stable Energy to Offshore Installations
Riboldi, Luca; Alves, Erick Fernando; Pilarczyk, Marcin; Tedeschi, Elisabetta; Nord, Lars O. (Peer reviewed; Journal article, 2020)This paper presents an innovative hybrid energy system for stable power and heat supply in offshore oil and gas installations. The proposed concept integrates offshore wind power, onsite gas turbines and an energy storage ... -
Optimal Design of Flexible Power Cycles through Kriging-based Surrogate Models
Riboldi, Luca; Nord, Lars O. (Chapter, 2018)The paper presents a novel technique to define the optimal design of a power cycle considering design and off-design performance. A Kriging-based surrogate model is developed in order to simulate the power cycle at design ... -
Optimal dynamic operation of natural gas combined cycles accounting for stresses in thick-walled components
Rúa, Jairo; Nord, Lars O.; Agromayor, Roberto; Hillestad, Magne (Journal article; Peer reviewed, 2020)Flexible natural gas combined cycles will play a fundamental role in future electric markets.Stressesinthick-walled components and gasturbine load ramps are arguably the main limiting factors during transient operation.Classical ... -
Optimal operation and control of heat to power cycles: A new perspective from a systematic plantwide control approach
Zotica, Cristina; Nord, Lars O.; Kovács, Jenő; Skogestad, Sigurd (Peer reviewed; Journal article, 2020)In this work, we use a plantwide control framework to systematically identify the control objectives, operational and environmental constraints, and degrees of freedom for a heat to power cycle with a drum, one pressure ... -
Optimal Operation and Control of Heat-to-Power Cycles: a New Perspective using a Systematic Plantwide Control Approach
Zotica, Cristina Florina; Nord, Lars O.; Kovács, Jenő; Skogestad, Sigurd (Journal article; Peer reviewed, 2019)We use a systematic plantwide control framework to analyze optimal operation of a simple heatto- power steam cycle with a single pressure level and a drum. The present control solutions for power plants1 have been developed ... -
Optimal scheduling of flexible thermal power plants with lifetime enhancement under uncertainty
Rúa, Jairo; Verheyleweghen, Adriaen; Jäschke, Johannes; Nord, Lars O. (Peer reviewed; Journal article, 2021)Renewable energy sources have been the focal point to decarbonise the power sector. The large deployment of these intermittent power generation units requires mechanisms to balance the grid. Thermal power plants can provide ... -
Optimisation of flexible operation of natural gas combined cycles with postcombustion CO2 capture
Pazos, Jairo Rúa (Doctoral theses at NTNU;2021:184, Doctoral thesis, 2021)Anthropogenic greenhouse gas emissions have continuously grown since the Industrial Revolution. Global warming is the result of increasing concentrations of these gases in the atmosphere, which create imbalances between ... -
Optimization of Organic Rankine Cycles for Waste Heat Recovery From Aluminum Production Plants
Castelli, Alessandro Francesco; Elsido, Cristina; Scaccabarozzi, Roberto; Nord, Lars O.; Martelli, Emanuele (Journal article; Peer reviewed, 2019)This paper presents the optimization of organic Rankine cycles (ORCs) for recovering waste heat from a hypothetical aluminum production plant to be installed in Norway. The case study is particularly interesting because ... -
Preliminary Design and Optimization of Axial Turbines Accounting for Diffuser Performance
Agromayor, Roberto; Nord, Lars O. (Journal article; Peer reviewed, 2019)Axial turbines are the most common turbine configuration for electric power generation and propulsion systems due to their versatility in terms of power capacity and range of operating conditions. Mean-line models are ... -
Process simulation and plant layout of a combined cycle gas turbine for offshore oil and gas installations
Bimüller, Johannes D.; Nord, Lars O. (Journal article; Peer reviewed, 2015)Since the development of the first oil fields on the Norwegian Continental Shelf, the petroleum industry in Norway has been making continuous progress in oil production engineering. With greater environmental awareness ...