Comparison of thermodynamic cycles in nuclear and coal power plant

Tato práce se zabývá tepelnými oběhy realizovanými ve velkých elektrárenských blocích. Shrnuje teoretické znalosti potřebné pro určování účinností skutečných tepelných oběhů v elektrárnách. V práci jsou popsány funkce jednotlivých zařízení používaných v tepelných obězích elektráren a jejich vliv na termickou účinnost. Tyto znalosti jsou použity pro určení účinností tepelných oběhů tří českých elektráren. Pro každou elektrárnu jsou stanoveny změny účinnosti při výpadku vybraných zařízení a vliv jednotlivých zařízení na celkovou termickou účinnost je vzájemně porovnán.This thesis deals with thermodynamic cycles realized in large power plant units. Theoretical knowledge necessary for assessing efficiency of real power plants is summarized. Functions of used devices are described together with their impact on cycle efficiency. Presented theoretical knowledge is then utilized to determine efficiencies of thermodynamic cycles in three Czech power plants. Change of thermodynamic efficiency caused by outage of selected devices is calculated for each power plant and mutually compared

Level of pre-medical first aid knowledge among recreational stay workers

Katedra tělesné výchovyFaculty of EducationPedagogická fakult

Open Phase Condition of a Nuclear Power Plant Power Supply

Tato práce se zabývá poruchami přerušení fáze při napájení vlastní spotřeby jaderné elektrárny. Nejprve rozebírá problematiku nesymetrických poruch a metody výpočtu parametrů soustavy při poruše přerušení fáze. Následně je rozebírán vliv jednotlivých zařízení elektrizační soustavy i zařízení vlastní spotřeby jaderné elektrárny při této poruše. Tyto znalosti jsou použity pro výpočet napěťových a proudových poměrů na rozvodnách vlastní spotřeby při této poruše v Jaderné elektrárně Temelín. Na základě zjištěných napětí i proudů jsou analyzovány dopady poruchy a možnosti její detekce.This thesis deals with the open phase condition on a nuclear power plant power supply. Firstly, asymmetrical failures are summarized together with calculation methods for the description of the open phase condition. Then, the influence of individual electrical power supply devices during the open phase condition is described. The presented theory is subsequently applied to a voltage and current calculation for the electrical substation of the Temelín nuclear power plant. Finally, the results of this calculation are used to analyze the possible impact of such a failure as well as the possible means of its detection

Effect of geotextile cover on snow and ice melt on Triangular Glacier, the north-eastern Antarctic Peninsula

A prominent increase in air temperature during the last decade has prompted summer melting and surface lowering of glaciers in the Antarctic Peninsula region. Accelerated mass loss from small land-terminating glaciers on James Ross Island has attracted research attention to local conditions of snow and ice melt that remain poorly known. This study focuses on the potential effects of non-woven geotextile on snow and ice melt on the surface of Triangular Glacier. The measurements of surface elevation changes reveal a total melt-season ablation of 1.3 to 1.6 m during the summer 2021/22. Over half of the melt season the surface lowering ranged from 0.5 m at the shaded glacier head to 0.8 m on the glacier surface unconstrained by topography, implying the importance of local topography on surface melting. The protection of glacier surface with non-woven geotextile covers reduced the snow and ice ablation by 40 to 69%. The lower effect of this protection is attributed to less intense surface melt at the shaded site. The efficiency of the geotextile cover is consistent with the reported values from mid-latitude sites but it is higher compared to the recently reported estimates from a high-elevation region in Asia

Snow and glacier melt contributions to streamflow on James Ross Island, Antarctic Peninsula

The Antarctic Peninsula is experiencing a rapid increase in air temperature, which has a major impact on the entire ecosystem, including the runoff process. Although water availability plays an important role in polar ecosystems, runoff generation in the Antarctic Peninsula region is still poorly understood. We analysed the variability in rain, snow and glacier contributions to runoff in relation to climate variability in a small, partly glaciated catchment on James Ross Island in the north-eastern Antarctic Peninsula. We used the hydrological model HBV to simulate the runoff process for the period 2010/11–2020/21 at a daily resolution. The model was calibrated against both measured discharge and glacier mass balance. Model simulations showed the negative mass balance of Triangular Glacier for 9 out of 11 study years with an average annual mass loss of 49 mm water equivalent. About 92 % of the annual runoff occurred between October and May. On average, peak runoff occurred in the second half of the summer season due to the combination of strong glacier and snow melt. The majority (76 %) of runoff originated from snowmelt, 14 % originated from glacier melt and 10 % from rainfall. The contribution of snowmelt to total runoff was higher in colder years with more precipitation. In contrast, glacier melt contributed dominantly during warmer years with less precipitation. Our simulation showed the presence of significant runoff-generating events outside the usual high summer runoff measurement season