4 research outputs found

    Start-up Optimization of a Combined Cycle Power Plant

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    In the electricity market of today, with increasing demand for electricity production on short notice, the combined cycle power plant stands high regarding fast start-ups and efficiency. In this paper it has been shown how the dynamic start-up procedure of a combined cycle power plant can be optimized using JModelica. org, proposing a way to minimize the start-up time while maximizing the power production during start-up. The physical models have been developed in Modelica, adapted to suit optimization purposes and extended to optimization problems. Constraints keeping the lifetime consumption of critically stressed components under control are limiting factors. The plant models have been successfully optimized to full load

    Start-up Optimization of a Combined Cycle Power Plant

    Get PDF
    In the electricity market of today, with increasing demand for electricity production on short notice, the combined cycle power plant stands high regarding fast start-ups and efficiency. In this paper it has been shown how the dynamic start-up procedure of a combined cycle power plant can be optimized using JModelica. org, proposing a way to minimize the start-up time while maximizing the power production during start-up. The physical models have been developed in Modelica, adapted to suit optimization purposes and extended to optimization problems. Constraints keeping the lifetime consumption of critically stressed components under control are limiting factors. The plant models have been successfully optimized to full load

    Optimization of the Start-up Procedure of a Combined Cycle Power Plant

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    In the electricity market of today, with increasing demand on electricity production on short notice, the combined cycle power plant stands high regarding fast start-ups and efficiency. In this thesis it has been shown how the start-up procedure of a combined cycle power plant can be optimized using JModelica.org, proposing a way to minimize the start-up time while maximizing the power production during start-up. The physical models have been developed in Modelica, adapted to suit optimization purposes and extended to optimization problems with the Optimica extension. Constraints keeping the lifetime consumption of critically stressed components under control have been limiting factors and the plant models have been successfully optimized to full load

    SARS‐CoV‐2‐specific humoral and cellular immunity persists through 9 months irrespective of COVID‐19 severity at hospitalisation

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    Objectives Humoral and cellular immunity to SARS-CoV-2 following COVID-19 will likely contribute to protection from reinfection or severe disease. It is therefore important to characterise the initiation and persistence of adaptive immunity to SARS-CoV-2 amidst the ongoing pandemic. Methods Here, we conducted a longitudinal study on hospitalised moderate and severe COVID-19 patients from the acute phase of disease into convalescence at 5 and 9 months post-symptom onset. Utilising flow cytometry, serological assays as well as B cell and T cell FluoroSpot assays, we assessed the magnitude and specificity of humoral and cellular immune responses during and after human SARS-CoV-2 infection. Results During acute COVID-19, we observed an increase in germinal centre activity, a substantial expansion of antibody-secreting cells and the generation of SARS-CoV-2-neutralising antibodies. Despite gradually decreasing antibody levels, we show persistent, neutralising antibody titres as well as robust specific memory B cell responses and polyfunctional T cell responses at 5 and 9 months after symptom onset in both moderate and severe COVID-19 patients. Conclusion Our findings describe the initiation and, importantly, persistence of cellular and humoral SARS-CoV-2-specific immunological memory in hospitalised COVID-19 patients long after recovery, likely contributing towards protection against reinfection.Medicin
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