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Paper on aerodynamic and mechanical design of large gas turbines presented by City, University of London and Baker-Hughes at ASME Turbo Expo, Boston (USA)

15 July, 2023/in Conference and journal papers /by jose

Turbine assembly cross section (©Baker Hughes Company, All Rights Reserved) The results of the collaboration between City, University of London (United Kingdom) and Baker-Hughes (Italy) have been have presented at ASME Turbo Expo in Boston (USA). This joint research has taken place within Work Package 3 – Turbomachinery Design of SCARABEUS, aimed at developing […]

Paper on energy losses in radial turbines presented by City, University of London at ASME Turbo Expo, Boston (USA)

15 July, 2023/in Conference and journal papers /by jose

Fan power consumption at reduced mass flow rate for different ACC designs The researchers at City, University of London have presented their work assessing the different contributions to energy losses experienced by radial turbines working with Carbon Dioxide mixtures in supercritical power cycles. This research work also considers the effect of turbine scale on […]

Paper on aerodynamic and mechanical design of large gas turbines presented by City, University of London and Baker-Hughes at ASME Turbo Expo, Boston (USA)

15 July, 2023/in Conference and journal papers /by jose

Paper on energy losses in radial turbines presented by City, University of London at ASME Turbo Expo, Boston (USA)

15 July, 2023/in Conference and journal papers /by jose

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Paper on aerodynamic and mechanical design of large gas turbines presented by City, University of London and Baker-Hughes at ASME Turbo Expo, Boston (USA)

15 July, 2023/in Conference and journal papers /by jose

The results of the collaboration between City, University of London (United Kingdom) and Baker-Hughes (Italy) have been have presented at ASME Turbo Expo in Boston (USA). This joint research has taken place within Work Package 3 – Turbomachinery Design of SCARABEUS, aimed at developing turbine designs able to attain high efficiency when working with Carbon Dioxide mixtures at very high pressures and temperatures.

Turbine design is strongly influenced by the composition of the working fluid because of the impact of this feature on the operating conditions of the cycle that attain peak thermal efficiency, and also the impact of composition on fluid characteristics.

Flow field of three different designs of the exhaust section

The paper presents the results of the unsteady simulations of the last turbine stage and exhaust section to assess unsteady loads on the rotor, as well as aerodynamic losses in the diffuser and exhaust section. Rotordynamics are also studied.

The paper can be downloaded free of charge from the conference website (link). Check the abstract below:

In this paper, the design of a large-scale axial turbine operating with supercritical carbon dioxide (sCO₂) blended with sulfur dioxide (SO₂) is presented considering aerodynamic and mechanical design aspects as well as the integration of the whole turbine assembly. The turbine is 130 MW, designed for a 100 MWe concentrated-solar power plant with turbine inlet conditions of 239.1 bar and 700 °C, total-to-static pressure ratio of 2.94 and mass-flow rate of 822 kg/s. The aerodynamic flow path, obtained in a previous study, is first summarised before the aerodynamic performance is evaluated using both steady-state and unsteady 3D numerical models to simulate the aerodynamic performance of the turbine. Whole-annulus unsteady simulations are performed for the last turbine stage and the exhaust section to assess the unsteady loads on the rotor due to downstream pressure field distortion and to assess aerodynamic losses of the diffuser and exhaust section. The potential low engine order excitation on the last rotor stage natural frequency modes due to downstream pressure distortion is assessed. The design of the turbine assembly is constrained by current manufacturing capabilities and the proposed working fluid properties. High-level flow-path design parameters, such as pitch diameter and number of stages, are established considering a trade-off between weight and footprint, turbine efficiency and rotordynamics. Rotordynamic stability is assessed considering the high fluid density related to cross coupling effects. Finally, shaft end sizing, cooling system design and the integration of dry gas seals are discussed.

Paper on energy losses in radial turbines presented by City, University of London at ASME Turbo Expo, Boston (USA)

15 July, 2023/in Conference and journal papers /by jose

Fan power consumption at reduced mass flow rate for different ACC designs

The researchers at City, University of London have presented their work assessing the different contributions to energy losses experienced by radial turbines working with Carbon Dioxide mixtures in supercritical power cycles. This research work also considers the effect of turbine scale on the breakdown of energy losses, assessing this for turbines in cycles rated at 0.1 MWe, 1 MWe and 10 MWe. The work makes use of meanline design codes and CFD analysis to assess the impact of fluid composition and scale and to compare the data obtained against data from literature.

Meridional profile of radial inflow turbines working with different Carbon Dioxide mixtures and with different scales (plots are not to scale)

The paper can be downloaded free of charge from the conference website (link). Check the abstract below:

Recent studies have indicated the potential of CO₂-mixtures to lower the cost of concentrated solar power plants. Based on aerodynamic and cost considerations, radial inflow turbines (RIT) can be a suitable choice for small to medium sized sCO₂ power plants (about 100 kW to 10 MW). The aim of this paper is to quantify the effect of doping CO₂ on the design of RITs. This is achieved by comparing the 1D mean-line designs and aerodynamic losses of pure sCO₂ RITs with those of three sCO₂ mixtures containing tetrachloride (TiCl4), sulphur dioxide (SO₂), and hexaflourobenzene (C₆F₆).

Results show that the optimal turbine designs for all working fluids will have similar rotor shapes and velocity diagrams. However, factors such as the clearance-to-blade-height ratio, turbine pressure ratio, and the difference in the viscosity of the fluids cause variations in the achievable turbine efficiency. Once the effects of these factors are eliminated, differences in the total-to-static efficiency amongst the fluids may become less than 0.1%. Moreover, if rotational speed limits are imposed, then greater differences in the designs and efficiencies of the turbines emerge amongst the fluids. It was found that limiting the rotational speed reduces the total-to-static efficiency in all fluids; the maximum reduction is about 15% in 0.1 MW CO₂ compared to the 3% reduction in CO₂/TiCl₄ turbines of the same power.

Among the mixtures studied, CO₂/TiCl₄ achieved the highest performance, followed by CO2/C6F6, and then CO2/SO2. For example, 100 kW turbines for CO₂/TiCl₄, CO₂/C₆F₆, CO₂/SO₂, and CO₂ achieve total-to-static efficiencies of 80.0%, 77.4%, 78.1%, and 75.5% respectively. Whereas, the efficiencies for 10 MW turbines are 87.8%, 87.3%, 87.5%, and 87.2%, in the same order. differences in the designs and efficiencies of the turbines emerge

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Paper on aerodynamic and mechanical design of large gas turbines presented by City, University of London and Baker-Hughes at ASME Turbo Expo, Boston (USA)

Paper on energy losses in radial turbines presented by City, University of London at ASME Turbo Expo, Boston (USA)

Paper on aerodynamic and mechanical design of large gas turbines presented by City, University of London and Baker-Hughes at ASME Turbo Expo, Boston (USA)

Paper on energy losses in radial turbines presented by City, University of London at ASME Turbo Expo, Boston (USA)

Full Sized Blog Element (Big Preview Pic)

Paper on aerodynamic and mechanical design of large gas turbines presented by City, University of London and Baker-Hughes at ASME Turbo Expo, Boston (USA)

Paper on energy losses in radial turbines presented by City, University of London at ASME Turbo Expo, Boston (USA)

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