Analysis of Coal-Fired Power Unit Operation in Reduced Minimum Safe Load Regime

Żymełka, Piotr; Żyrkowski, Maciej; Bujalski, Maciej

doi:10.5772/intechopen.72954

Cited by 3 publications

(3 citation statements)

References 16 publications

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“…40 The typical operating mode is at 100% MCR (Maximum Continuous Rating) on daytime and between 40%MCR to 65%MCR conditions on nighttime, with the minimum load dictated by safe load operation of the boiler. 14 Derating is accomplished by reducing the reactant flow rate (fuel plus oxidizer) into the boiler thus lowering both heat release rate and flame temperature. Accordingly, off-design simulations were run under linearly decreasing fuel consumption and furnace temperature while reducing the load (Figure 4).…”

Section: Partial Load Operationmentioning

confidence: 99%

“…10 It is recommended to deeply characterize the minimum technical load in terms of thermal input, steam temperature and flue gas temperature, also with the help of modelling study and predictive tools. [11][12][13][14][15] In fact, a flue gas temperature lower than the nominal value can adversely affect the cleaning systems, such as selective catalytic reduction (SCR) and wet flue gas desulphurization (FGD) units because of changes in chemistry. There is also a risk of flue gas temperature falling below dew point of SO 3 so that acidic moisture condenses on particles, with a negative impact on the fabric filter.…”

Section: Introductionmentioning

confidence: 99%

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Performance evaluation of a supercritical circulating fluidized bed boiler for power generation under flexible operation

Bruzzone

Ravelli

2021

Proceedings of the Institution of Mechanical Engineers, Part A:

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It is well known that the Łagisza power plant in Poland is the world’s first supercritical circulating fluidized bed (CFB) boiler, whose commercial operation started on June 2009. It has attracted a great deal of interest and operational data are publicly available, therefore it has been chosen as the object of the present study aimed at assessing load and fuel flexibility of supercritical CFB plants. First, the thermal cycle was modelled, by means of the commercial code Thermoflex®, at nominal and part load conditions for validation purposes. After having verified the validity of the applied modelling and simulation tool, the advantage of having supercritical steam combined with CFB boiler over subcritical steam and pulverized coal (PC) boiler, respectively, was quantified in terms of electric efficiency. As a next step, the designed fuel, i.e. locally mined hard coal, was replaced with biomass: 100% biomass firing was taken into account in the case of subcritical CFB boiler whereas the maximum share of biomass with coal was set at 50% with supercritical CFB boiler, consistently with the guidelines provided by the world leading manufacturers of CFB units. A broad range of biomass types was tested to conceive mixtures of fuel capable of preserving quite high performance, despite the energy consumption in pretreatment. However, the overall efficiency penalty, due to biomass co-firing, was found to potentially undermine the benefit of supercritical steam conditions compared to conventional subcritical power cycles. Indeed, the use of low-quality biomass in thermal power generation based on steam Rankine cycle may frustrate efforts to push the steam cycle boundaries.

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Section: Partial Load Operationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Performance evaluation of a supercritical circulating fluidized bed boiler for power generation under flexible operation

Bruzzone

Ravelli

2021

Proceedings of the Institution of Mechanical Engineers, Part A:

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“…Çàðóб³жí³ äîñл³äíèêè âже äàâíî ä³éшлè âèñíîâêó, щî çб³лüшеííя ÷àñòêè íеðегóлüîâàíèõ â³äíîâлюâàíèõ äжеðел пîòðебóâàòèìе çб³лüшеííя ðегóлюâàлüíîгî çàпàñó пîòóжíîñòеé, яêèé ìîжíà ðеàл³çóâàòè пðè çб³лüшеíí³ ÷àñòêè âèðîблеííя ТЕС яê єäèíîгî íàä³éíîгî ðегóляòîðà àбî пðè îбìежеíîìó âèðîблеíí³, àле пðè ðîçшèðеíí³ ä³àпàçîíó ðегóлюâàííя íàâàíòàжеííя òеплîâèõ еíеðгîблîê³â. Ç óðàõóâàííяì цüîгî ó ðîбîò³ [11] У 2020 ðîц³ пîð³âíяíî ç 2019 ðîêîì пèòîìà âèòðàòà пàлèâà íà â³äпóñê елеêòðîеíеðг³ї ТЕС çðîñлà â³ä 402,7 äî 404,8 г ó.п./(êÂò⋅гîä), пðè цüîìó ñеðеäí³é ð³âеíü ìеõàí³÷íîгî íеäîпàлó бóâ íеâелèêèì òà пðàêòè÷íî íе çì³íèâñя (òàбл. 5).…”

Section: чинники òеплової еконоì³чноñò³ тес òа їх зì³на в уìовах зроñ...unclassified

State and Prospects of Thermal Power Generation in the Conditions of Ukraine’s Course on Carbon-Free Energy

Cherniavskyi

2021

Energ. Tech. & Res. Sav.

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The structure of electricity cost formation for consumers, including depending on the cost of TPP generation, «green» energy and other sources, is investigated, and the main conditions of the efficient regulatory function fulfillment in the power system by thermal power generation in the conditions of Ukraine's course on carbon-free energy are formulated. It is shown that excessive electricity losses in networks and, especially, accelerated increase of the share of «green» generation, much more expensive than nuclear, hydro and thermal, mainly contribute to the growth of electricity costs for non-household consumers and the need to raise tariffs for the population. This accelerated increase directly contradicts the Paris Climate Agreement, according to which plans to reduce Ukraine’s greenhouse gas emissions must be developed taking into account available energy resources and without harming its own economy. The dependences of the specific fuel consumption on the average load and the frequency of start-stops of units are found and it is shown that the increased specific fuel consumption on coal TPPs is an inevitable payment for their use as regulating capacities of UES of Ukraine. In this case, the higher the proportion of «green» generation and a smaller proportion of generating thermal power plants, especially increasing specific fuel consumption. It is proved that in the conditions of growth of the share of «green» generation in Ukraine the share of production of pulverized coal thermal power plants should be kept at the level of not less than 30 % of the total electricity generation. It is substantiated that a necessary condition for coal generation to perform a proper regulatory role in the power system is to introduce both environmental and technical measures, namely — reducing the suction of cold air to the furnace and other boiler elements, restoring condensers and cooling systems, etc. An important factor in reducing the average level of specific fuel consumption is also the reduction of coal burn-out at thermal power plants, where it still remains significant, due to the transfer of power units to the combustion of bituminous coal concentrate. Bibl. 12, Fig. 5, Tab. 5.

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