Thermal-power cycles operating with supercritical carbon dioxide (sCO2) could have a significant role in future power generation systems applications including fossil fuel, nuclear power, concentrated-solar and waste-heat recovery. The use of sCO2 as working fluid offers potential benefits high thermal efficiencies using heat-source temperatures ranging between approximately 350∘C 800∘C, simple compact physical footprint, good operational flexibility, which realise lower levelised costs...

In March 2023, the European Parliament and Council reached a consensus to increase binding renewable energy target (RES) minimum of 42.5% by 2030, effectively doubling proportion RES from 2020 baseline. This significant development aligns EU more closely with objectives Green Deal REPowerEU initiative. High-temperature heat pumps (HTHP), due their appropriateness for industrial-scale applications, integrate perfectly within this progressive trajectory. They enable waste generated various...

An advanced numerical model for the simulation of steady and unsteady viscous compressible e ows turbomachinery applications is described. The Favre-averaged Navier ‐Stokes equations are used together with a one-equation turbulence model. ow domain discretized using unstructured hybrid grids that can contain mixture hexahedral, pentahedral, tetrahedral, triangular prismatic cells. node-centered nite volume scheme relies on representing mesh an edge-based data structure. A dual time stepping...

Abstract This paper describes a novel way of prescribing computational fluid dynamics (CFD) boundary conditions for axial-flow compressors. The approach is based on extending the standard single passage domain by adding an intake upstream and variable nozzle downstream. Such route allows us to consider any point given speed characteristic simply modifying area, actual being set atmospheric ones in all cases. Using fan blade, it shown that method not only going past stall but also captures...

The utilisation of certain blends based on supercritical CO2 (sCO2), namely CO2/TiCl4, CO2/C6 F6 and CO2/SO2, have been found to be promising for enhancing the performance power cycles Concentrated Solar Power (CSP) applications; allowing up a 6% enhancement in cycle efficiency with respect simple recuperated cycle, depending upon nature used blend configuration choice. This paper presents an investigation impact adopting these sCO2-based flow path design multi-stage axial turbine whilst...

Loss models are used to evaluate the aerodynamic performance of axial turbines at preliminary design stage. The commonly loss were derived for air and steam have not been sufficiently investigated working with non-conventional fluids, relevant new power systems, such as organic fluids supercritical CO2 (sCO2). Thus, aim this study is explore deviation between predictions different models, namely Dunham Came, Kacker Okapuu, Craig Cox Aungier, where may differ in operation than conventional or...

Supercritical carbon dioxide (sCO2) can be mixed with dopants such as titanium tetrachloride (TiCl4), hexafluoro-benzene (C6F6), and sulphur (SO2) to raise the critical temperature of working fluid, allowing it condense at ambient temperatures in dry solar field locations. The resulting transcritical power cycles have lower compression work higher thermal efficiency. This paper presents aerodynamic flow path design a utility-scale axial turbine operating an 80–20% molar mix CO2 SO2....

The integration of thermal-energy storage (TES) within waste-heat recovery power generation systems has the potential to improve energy-efficiency in many industrial processes with variable and/or intermittent streams. first objective this paper is present a novel model these that can be used at an early design stage provide fast and accurate estimates performance. More specifically, method identify optimal temperature latent-heat TES for applications based only on known heat-source...

Supercritical carbon dioxide (sCO2) power cycles are promising candidates for concentrated-solar and waste-heat recovery applications, having advantages of compact turbomachinery high cycle efficiencies at heat-source temperature in the range 400 to 800 ∘C. However, distributed-scale systems (0.1–1.0 MW) choice type is unclear. Radial turbines known be an effective machine micro-scale applications. Alternatively, feasible single-stage axial turbine designs could achieved allowing better heat...

A e rst aim is to distinguish between two utter regimes that are commonly referred as stall because of their occurrence a raised working line and the boundary. The one aeroacoustic origin, it arises from match acoustic impedance intake duct upstream pressure perturbation due fan vibration. second type directly related ow separation effects shock properties. Further objectives describe several numerical prediction methods, compare relative computational requirements, establish bounds...

The aim of this paper is to conduct a generalised assessment both optimal working fluids and radial turbine designs for small-scale organic Rankine cycle (ORC) systems across range heat-source temperatures. former has been achieved by coupling thermodynamic model subcritical, non-recperated cycles with the Peng–Robinson equation state, optimising working-fluid parameters temperatures ranging between 80 ° C 360 . critical temperature fluid found be an important parameter governing selection....

The design of optimal organic Rankine cycle (ORC) systems requires the simultaneous identification architecture, operating conditions and working fluid, whilst accounting for effect these parameters on expander performance. In this paper, a novel method predicting design-point efficiency radial turbine is developed, which can predict achievable based only thermodynamic conditions. This model integrated into an optimisation framework in fluid modelled using Peng-Robinson equation state (i.e.,...

Supercritical CO2 (sCO2) power cycles have gained prominence for their expected excellent performance and compactness. Among benefits, they may potentially reduce the cost of Concentrated Solar Power (CSP) plants. Because critical temperature is close to ambient temperatures in areas with good solar irradiation, dry cooling penalise efficiency sCO2 CSP Recent research has investigated doping different materials increase its temperature, enhance thermodynamic cycle performance, adapt it arid...

A numerical study of a labyrinth-type turbine seal flutter in large turbofan engine is described. The analysis was conducted using coupled fluid-structure interaction code, which originally developed for turbomachinery blade applications. flow model based on an unstructured, implicit Reynolds-averaged Navier–Stokes solver. solver to modal the structure obtained from standard structural finite element code. During aeroelasticity computations, aerodynamic grid moved at each time step follow...

This paper focuses on the optimisation of small-scale micro gas turbines totally powered by concentrated solar power to generate electricity in range 5–30kWe. The objective this is investigate potential such systems for generation at reasonable costs. computational model uses a component-based approach thermodynamic performance simulation and features an integrated economic which allows evaluation indicators including levelised cost electricity. coupled genetic algorithm framework find...

This paper presents an analysis and experimental investigation of the effect integrating Phase Change Material (PCM) within a heat exchanger Micro Combined Heat Power (Micro-CHP) system intended for residential applications. A commonly used Micro-CHP layout is replicated in test rig to characterise performance two alternative arrangements. The first conventional arrangement where exhaust gas produced by prime mover directed air-to-water water store it tank. In second arrangement, PCM...

This paper describes the formulation and application of an advanced numerical model for simulation blade-passing low-engine order forced response in turbomachinery core compressors. The Reynolds averaged Navier–Stokes equations are used to represent flow a nonlinear time-accurate fashion on unstructured meshes mixed elements. structural is based standard finite-element representation. fluid mesh moved at each time step according motion so that changes blade aerodynamic damping unsteadiness...

Fan blades of high bypass ratio gas turbine engines are subject to substantial aerodynamic and centrifugal loads, producing the well-known phenomenon fan blade untwist. The accurate prediction running geometry, as opposed cold geometry at rest, is crucial in assessment performance, vibratory response, noise production fan. situation further complicated by fact that some geometric variation inevitable even for state-of-the-art manufacturing processes used. aim this paper investigate effect...

Computational analyses such as computational fluid dynamics and structural have made major advances towards maturity engineering tools. aeroelasticity (CAE) is the integration of these disciplines. As CAE matures, it also finds an increasing role in design analysis aerospace vehicles. This paper presents a survey current state with discussion recent research, success continuing challenges its progressive into multidisciplinary design. It approaches from perspective two main areas...

For small-scale organic Rankine cycles (ORCs) to be a competitive technology, it is reasonable assume that the same turbine design will implemented into range of different applications. It therefore critical able predict off-design performance over operating conditions while utilizing working fluids. Similitude theory can used for this purpose, and has been well validated ideal gases. However, cannot said its applications fluids found within ORCs. This paper considers candidate subsonic with...