Attractive nuclear energy
Energetyka 2011, nr 5, p. 267
Nuclear energy is one of the most attractive, from the economic point of view, technologies of electric energy generation. Despite the relatively high capital costs, resulting mainly from high safety standards and technical safety requirements applied in this industrial branch, the cost of electric energy generation (LDEGC) is comparable to, and in case of 5% discount rate even lower than, the one achieved in power industry based on coal or natural gas, taking into account the costs of carbon dioxide emission. Thus, the statement that nuclear energy is the most expensive way of electric energy generation cannot be confirmed by the facts published in the article.
Keywords: nuclear energy, nuclear energy costs, nuclear power plants of III+ generation
Herbert Leopold Gabryś
Power industry in Poland – 2011. Selected effects and challenges emerging in the year 2010 with special attention paid to problems resulting from the EU Climate and Energy Package
Energetyka 2011, nr 5, p. 271
Discussed are partial effects achieved by the Polish power industry in 2010. Attention is paid to the far-reaching consequences for Poland of the introduced by the EU Climate and Energy Package, emphasizing the fact that these consequences will affect the whole national economy and the Polish society as well and not only, as till now, companies belonging to the fuel and energy sector.
Keywords: effects achieved by the Polish power industry in 2010, the EU Climate and Energy Package, consequences for the Polish economy
Overview of design and beyond-design basis accidents in nuclear power plants
Energetyka 2011, nr 5, p. 274
The paper presents problems concerning postulated severe accidents and engineered safety features for their management in a new nuclear power plants. It has been shown that such an accidents can lead to core meltdown. They are caused by cooling system failures or by reactivity accidents initiated by control rod ejection. Described are safety systems to mitigate the consequences of radioactive material release limited by regulated radiation dose allowed. Two concepts to hold corium within the reactor are implemented: in – vessel-cooling system, which could prevent corium from leak outside the reactor and specific melted fuel catcher situated below the reactor pressure vessel. Considered are also beyond design basis accidents, albeit that due to very low propability of occurrence they usually do not take into consideration in Safety Analysis Report for nuclear power plants.
Keywords: nuclear power plants, design basis accidents
Roman KORAB, Robert OWCZAREK
Cross-border power flow control by using phase shifting transformers
Energetyka 2011, nr 5, p. 279
The current structure of the European interconnected power system as well as the schedule of generation between and within each of its parts are the main reasons of the loop flows that are systematically observed in the region of Central and Eastern Europe. These unscheduled compensatory power flows can occupy a significant part of the cross-border transmission capacity of the Polish Power System, thereby limiting the amount of transmission capacity which is available to the market participants interested in cross-border energy trading. One possible way that allow to reduce – and sometimes even to eliminate – loop flows is to use some devices that enables the Transmission System Operator to control the active power flows in the power system. These devices include the so-called phase shifting transformers. The paper discusses selected results of research whose main objective was to determine the effect of phase angle control of 400/220 kV transformers installed in Polish 400 kV border stations on the cross-border power flows.
Keywords: cross-border transmission lines, power flow control, phase shifting transformers
The influence of the method of THD factor determination on assigned inaccuracy caused by the utilization of instrument transformers in indirect distorted signals measurements
Energetyka 2011, nr 5, p. 285
Abstract The subjects of the laboratory research were determination of the THD factor measurement inaccuracy caused by the instrument transformers in conditions of distorted signals transformation and investigation of the applicability of the usage of this phenomena in voltage and current transformers accuracy definition for distorted signals.
Keywords: voltage transformers, current transformers, distorted voltages and currents, accuracy of distorted signals transformation, THD factor determination, power quality
Measurement of local heat flux in boiler combustion chambers
Energetyka 2011, nr 5, p. 288
Proposed is a new method of determining the local heat load on the walls of boilers’ combustion chambers. For the purpose of this measurement an eccentric insert is used, inside which some thermoelements are fitted. The eccentric measuring tube wall, from the side of a furnace, is thicker what enables more accurate load measurement as the distance between thermoelements is bigger. Also bigger are the differences in temperature shown by the thermoelements fitted in the front part of the insert. Influence of thermoelements’ location inaccuracy on the uncertainty of the determined heat load is also smaller because of bigger distances between thermoelements. Considered is that the heat conduction factor of the steel which thermometric insert is made of, depends on temperature. The measuring tube outer wall radiant coefficient and the thermal field in the insert cross-section are determined with the help of finite element method (FEM). On the basis of the carried out computer simulation determined is the function presenting heat load dependence on the characteristic temperature differences occurring in the front part of the insert. It enables fast and accurate determination of the heat load.
Keywords: boilers, combustion chamber walls, heat load measurement
Durability of power boilers’ pressure parts in the perspective of their further operation
Energetyka 2011, nr 5, p. 291
Possibility of further electric energy generation by long-operated domestic power plants depends on the actual technical condition of power facilities working there. Taken up are the problems connected with assessment of the remaining operational lifetime of a boiler’s main pressure elements. Discussed are the applied operational lifetime calculation methods as well as metalographic methods used to determine the level of material exhaustion. Presented are technical condition diagnostic tests of a boiler drum, superheater chambers, main pipelines and other power boiler elements. Given are exemplary results taken from the research practice.
Keywords: power boilers, boiler’s pressure elements, operational lifetime assessment
Generation of energy from renewable sources in the combustion process of a secondary mixed fuel containing biomass
Energetyka 2011, nr 5, p. 298
Presented are problems referring to the possibility of electric energy and heat generation from renewable sources, its balancing and achieving „green certificates” by applying in the technological process the so-called mixed secondary fuel which, according to the Polish law, is defined as the mixture of coal and biomass prepared somewhere outside the company combusting this fuel. Discussed are successive problems - beginning from legal and metrological requirements, through financial settlement methodology, ending with performance tests results.
Keywords: energy from renewable sources, mixed fuel combustion, biomass
Financial settlement of renewable sources energy generation in the case of biogas and natural gas co-combustion in cogeneration units
Energetyka 2011, nr 5, p. 305
Generation of electric energy in the process of combusting in cogeneration units the biogas produced at municipal landfill sites and sewage treatment plants, needs concession issued by the President of Energy Regulatory Office. Achieving the concession enables moving resolution to issue „green certificates” but before it happens it is necessary to conform the measuring and financial settlement system to Polish legal regulations. Described is a proposed solution of the problem.
Keywords: renewable sources, biogas combustion, electric energy generation, financial settlement method of electric energy generation
Emilia Anna JAKUBAS
Possibility to make use of devastated barrages to build small water-power plants (on the example of MEW Oborniki)
Energetyka 2011, nr 5, p. 310
Discussed are technical and ecological aspects of constructing small water-power plants in the areas where devastated barrages could be found on the example of MEW Oborniki in Wielkopolska part of Poland.
Keywords: small water-power plants, technical and ecological aspects, environmental advantages