The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform
Xiaodong Ren - One of the best experts on this subject based on the ideXlab platform.
-
Performance Improvement of a Supercritical CO2 and Transcritical CO2 Combined Cycle for Offshore Gas Turbine Waste Heat Recovery
Volume 11: Structures and Dynamics: Structural Mechanics Vibration and Damping; Supercritical CO2, 2020Co-Authors: Aozheng Zhou, Xiaodong RenAbstract:Abstract The supercritical CO2 (S-CO2) and transcritical CO2 (T-CO2) combined cycle is a promising technology for the waste heat recovery of the Offshore Gas turbine. In this paper, a new system layout is proposed to investigate the thermodynamic and economic performances improvement of the S-CO2-T-CO2 combined cycle. Compared to the original systems, the residual heat of the topping S-CO2 cycle is recovered and extra recuperation is added to the bottoming T-CO2 cycle. Sensitivity analysis of different systems is carried out based on the mathematical model and multi-objective optimization is conducted. The net power out and the net present value (NPV) are chosen as the objective functions of thermodynamic and economic aspects. The results reveal that at the design point, the improved system has more than 8.23% increment on the net power output and 3.55% increment on the NPV. Besides, the optimized net power output of the improved system attains at least 5.16% increment with 3.15% increment for the optimized NPV at the same time. The improved system can be applied in some practical cases from both the thermodynamic and economic views.
-
Improvement design and analysis of a supercritical CO2/transcritical CO2 combined cycle for Offshore Gas turbine waste heat recovery
Energy, 2020Co-Authors: Aozheng Zhou, Xiaodong RenAbstract:Abstract The supercritical CO2 (S–CO2) and transcritical CO2 (T-CO2) combined cycle is considered a promising technology for Offshore Gas turbine waste heat recovery. To further improve the thermodynamic and economic performances of the S–CO2/T-CO2 combined cycle for Offshore Gas turbine waste heat recovery, a new system layout is proposed in this paper. The net power output and net present value (NPV) are chosen as the objective functions of thermodynamic and economic performances, respectively. Compared to the basic systems presented by previous researchers, the new proposed S–CO2/T-CO2 combined cycle layout is modified in two aspects. One is that the residual heat of the topping S–CO2 cycle can be recovered by the bottoming T-CO2 cycle. The other is that a split flow branch is added in the bottoming T-CO2 cycle. The sensitivity analysis of different systems is carried out to explore the allowable ranges of independent parameters. Compared with the two basic layouts (Basic-I and Basic-II), the simulation results at the design point reveal that the proposed system has more than 10.53% increment on the net power output and 7.87% increment on the net present value (NPV). Besides, the multi-objective optimization results indicate the proposed system attains at least 8.30% increment on the optimized net power output and 3.79% increment on the optimized NPV at the same time. It is proved that the proposed system can be applied in some practical cases from the thermodynamic and economic views.
Aozheng Zhou - One of the best experts on this subject based on the ideXlab platform.
-
Performance Improvement of a Supercritical CO2 and Transcritical CO2 Combined Cycle for Offshore Gas Turbine Waste Heat Recovery
Volume 11: Structures and Dynamics: Structural Mechanics Vibration and Damping; Supercritical CO2, 2020Co-Authors: Aozheng Zhou, Xiaodong RenAbstract:Abstract The supercritical CO2 (S-CO2) and transcritical CO2 (T-CO2) combined cycle is a promising technology for the waste heat recovery of the Offshore Gas turbine. In this paper, a new system layout is proposed to investigate the thermodynamic and economic performances improvement of the S-CO2-T-CO2 combined cycle. Compared to the original systems, the residual heat of the topping S-CO2 cycle is recovered and extra recuperation is added to the bottoming T-CO2 cycle. Sensitivity analysis of different systems is carried out based on the mathematical model and multi-objective optimization is conducted. The net power out and the net present value (NPV) are chosen as the objective functions of thermodynamic and economic aspects. The results reveal that at the design point, the improved system has more than 8.23% increment on the net power output and 3.55% increment on the NPV. Besides, the optimized net power output of the improved system attains at least 5.16% increment with 3.15% increment for the optimized NPV at the same time. The improved system can be applied in some practical cases from both the thermodynamic and economic views.
-
Improvement design and analysis of a supercritical CO2/transcritical CO2 combined cycle for Offshore Gas turbine waste heat recovery
Energy, 2020Co-Authors: Aozheng Zhou, Xiaodong RenAbstract:Abstract The supercritical CO2 (S–CO2) and transcritical CO2 (T-CO2) combined cycle is considered a promising technology for Offshore Gas turbine waste heat recovery. To further improve the thermodynamic and economic performances of the S–CO2/T-CO2 combined cycle for Offshore Gas turbine waste heat recovery, a new system layout is proposed in this paper. The net power output and net present value (NPV) are chosen as the objective functions of thermodynamic and economic performances, respectively. Compared to the basic systems presented by previous researchers, the new proposed S–CO2/T-CO2 combined cycle layout is modified in two aspects. One is that the residual heat of the topping S–CO2 cycle can be recovered by the bottoming T-CO2 cycle. The other is that a split flow branch is added in the bottoming T-CO2 cycle. The sensitivity analysis of different systems is carried out to explore the allowable ranges of independent parameters. Compared with the two basic layouts (Basic-I and Basic-II), the simulation results at the design point reveal that the proposed system has more than 10.53% increment on the net power output and 7.87% increment on the net present value (NPV). Besides, the multi-objective optimization results indicate the proposed system attains at least 8.30% increment on the optimized net power output and 3.79% increment on the optimized NPV at the same time. It is proved that the proposed system can be applied in some practical cases from the thermodynamic and economic views.
H.j. Lindeboom - One of the best experts on this subject based on the ideXlab platform.
-
Marine fouling assemblages on Offshore Gas platforms in the southern North Sea
PLOS ONE, 2016Co-Authors: Van Der Tim Stap, Joop W. P. Coolen, H.j. LindeboomAbstract:Offshore platforms are known to act as artificial reefs, though there is on-going debate on whether this effect is beneficial or harmful for the life in the surrounding marine environment. Knowing what species exist on and around the Offshore platforms and what environmental variables influence this species assemblage is crucial for a better understanding of the impact of Offshore platforms on marine life. Information on this is limited for Offshore platforms in the southern North Sea. This study aims to fill this gap in our knowledge and to determine how the composition and the abundance of species assemblages changes with depth and along a distance-from-shore gradient. The species assemblages on five Offshore Gas platforms in the southern North Sea have been inventoried using Remotely Operated Vehicles inspection footage. A total of 30 taxa were identified. A Generalised Additive Model of the species richness showed a significant non-linear relation with water depth (p = 0.001): from a low richness in shallow waters it increases with depth until 15–20 m, after which richness decreases again. Using PERMANOVA, water depth (p≤0.001), community age (p≤0.001) and the interaction between distance from shore and community age (p≤0.001) showed a significant effect on the species assemblages. Future research should focus on the effect additional environmental variables have on the species assemblages.
Gianna Fabi - One of the best experts on this subject based on the ideXlab platform.
-
Trophic structure of polychaetes around an Offshore Gas platform.
Marine Pollution Bulletin, 2015Co-Authors: E. Punzo, Pierluigi Strafella, Giuseppe Scarcella, A. Spagnolo, A. M. De Biasi, Gianna FabiAbstract:The distribution of polychaetes associated with an Offshore Gas platform built on a muddy-sandy bottom in the northern Adriatic Sea was investigated with emphasis on their feeding structure. Polychaete species were collected at different distances from the rig using a Van Veen grab. Assessment of the polychaete community and trophic groups for impacts related to the presence of the platform demonstrated significantly different abundances at rising distances from the rig. The present findings highlight an effect of the rig on the spatial distribution of polychaete assemblages. Even though the effects of Gas platforms on surrounding benthic communities have been investigated in the Adriatic Sea, no studies have addressed the distribution of polychaete trophic groups along a gradient based on distance from the rig.
-
A multidisciplinary approach to evaluate the environmental impact of Offshore Gas platforms in the western Adriatic Sea
Chemistry and Ecology, 2011Co-Authors: Alessio Gomiero, Giuseppe Scarcella, A. Spagnolo, A. M. De Biasi, L. Da Ros, C. Nasci, Gianna FabiAbstract:Detecting the anthropogenic impacts of Offshore Gas platforms requires reliable tools, because the traditional evaluation based only on chemical analyses is neither appropriate nor sufficiently sensitive. Thus, a 3-year monitoring project was carried out to evaluate the impact of a platform based on a chemical–biological approach. Benthic communities are investigated as they are widely used to monitor the effects of marine impacts because the organisms are mostly sessile and integrate the effects of pollutants over time. Changes in benthic infauna, sediments and water quality, as well as biota bioaccumulation, caused by drilling and platform operations were evaluated experimentally. Furthermore, mussels (Mytilus galloprovincialis) were collected seasonally from the platform legs, both close to and far from the sacrificial anodes and at a control site. Responses of biomarkers of exposure and effect were related to the average levels of polycyclic and aliphatic hydrocarbons, organic matter content and heavy...
-
Effects of two Offshore Gas platforms on soft-bottom benthic communities (northwestern Adriatic Sea, Italy).
Marine environmental research, 2010Co-Authors: Sarine Manoukian, E. Punzo, Giuseppe Scarcella, A. Spagnolo, Roberta Angelini, Gianna FabiAbstract:Abstract The macrozoobenthos living around two Offshore Gas platforms, Barbara NW (pB) and Calipso (pC) located in the northwestern Adriatic Sea were investigated for three years after their construction to detect eventual effects due to the platforms. The sampling stations were spaced at increasing distance from the platforms up to 1000 m. Both multivariate and univariate analysis showed an initial defaunation (short-term effect) at pB and within a 120 m radius at pC. A general recovery in terms of abundance, species richness and diversity was observed for the benthic communities after one year. During the third monitoring year a mussel mound developed at both the platforms (longer-term effect) extending up to 30 m from pC, whereas similar soft-bottom communities were found at all the other distances. The geographical position plays an important role in the “timing” of the above effects. Moreover, despite the different environmental features, a 3-year monitoring plan can be effective to evaluate the potential impact on benthic communities of Offshore Gas platforms in the north-central Adriatic Sea.
Ju Pei - One of the best experts on this subject based on the ideXlab platform.
-
hydrate formation and decomposition regularities in Offshore Gas reservoir production pipelines
Energies, 2020Co-Authors: Na Wei, Yingfeng Meng, Jinzhou Zhao, Jo Kvamme, Shouwei Zhou, Liehui Zhang, Yao Zhang, Li Jiang, Ju PeiAbstract:In recent years, the exploitation and utilization of Offshore oil and Gas resources have attracted more attention. In Offshore Gas reservoir production, wellbore temperature and pressure change continuously when water-bearing natural Gas flows upward. The wellbore temperature is also affected by the low-temperature sea water. The combination of temperatures and pressures controlled by the upward flow, and cooling from the surrounding seawater frequently leads to the conditions of temperature and pressure for hydrate formation. This can lead to pipeline blockage and other safety accidents. In this study, we utilize mathematical models of hydrate phase equilibrium, wellbore temperature, wellbore pressure to study hydrate formation and decomposition in Offshore Gas reservoir production. Numerical solution algorithms are developed and numerical solutions are validated. The sensitivity influence of different parameters on the regions and regularities of hydrate formation and decomposition in wellbores are obtained through numerical simulations. It is found that increased daily Gas production, water content, or geothermal gradient in Offshore Gas reservoir production pipelines results in less hydrate formation in the wellbores. Accordingly, the risk of wellbore blockage decreases and production safety is maintained. Decreased tubing head pressure or seawater depth results in similar effects. The result of this study establishes a set of prediction methods for hydrate formation and decomposition that can be used in the development of guidelines for safe construction design.
