Tomasz CZAKIERT, Wojciech NOWAK
Oxy-combustion in PC, CFB and PCFB power units
Oxy-combustion is actually a subject of detailed experimental studies as well as of technical and economic analyses being carried on as one of the four Research Tasks - Project No 2 entitled “Oxy-combustion technology for PC and FBC boilers with CO2 capture” and realized within the frames of the Research and Development Strategic Program “Advanced Technologies for Energy Generation” supported by the National Centre for Research and Development (NCBR) in Poland. The broad range of investigations includes first of all basic investigations and specific processes on a bench scale, technology research on a pilot scale as well as the problems concerning oxygen production and purification of the obtained CO2. Complex handling of constituent processes and their realizing systems is to finally lead to elaboration of a feasibility study for an oxyfuel power unit with CCS. The investigations are also to help select one of the three analyzed in this project coal combustion technologies i.e. PC (pulverized coal combustion), CFB (circulating fluidized bed) and PCFB (pressurized circulating fluidized bed) that eventually will be recommended for oxyfuel combustion.
One of the more important problems, brought up for discussion in the frames of this project, is also the estimation of adaptive abilities of the part-worn older power units intended in the derogation program to realize oxyfuel combustion what in turn could become an option for power restoring and modernization of the Polish power system. It is also assumed that the results and analyses carried out in the Project No 2 will become especially helpful at the stage of making decisions concerning further development of clean coal technologies in Poland.
Keywords: oxyfuel combustion, strategic program, CO2 capture
Henryk ŁUKOWICZ, Andrzej KOCHANIEWICZ
Analysis of the use of waste heat in the turbine regeneration system of a 900 MW supercritical coal-fired power unit
Determined are factors of a 900 MW supercritical coal-fired power unit working with the use of a flue gas heat recovery system. Analysis is made of various options of flue gas heat recovery for heating the condensate flowing through the low-pressure regeneration system as well as the feed water in the high-pressure regeneration exchangers. Examined was the influence of a localization of a place where the heated condensate is injected into the circuit on the power unit efficiency and capacity. The analysis was carried out for two different ways of waste heat use - in one of them it is only the heat recovered from flue gases at the boiler outlet (after the air heater) that is used to heat water in the regeneration system while in the other utilized is also the additional heat recovered from flue gases before the air heater. Investigations were made for flue gases produced in the process of hard and brown coal combustion separately.
Keywords: waste heat recovery, coal-fired power units, power plant efficiency, low-temperature heat
Katarzyna JANUSZ-SZYMAŃSKA, Grzegorz WICIAK
Comparative analysis of numerical simulation and experimental measurement results in the context of CO2 separation membrane method parameters investigation
Described is the methodology of analysis conducted for the results of numerical investigations aimed at determination of separation process mathematical model elements with the application of a polymeric membrane. The data needed for elaboration of this model were obtained by way of an experiment. Comprised is also a comparative analysis of experimental data and numerical calculations results. Presented are assumptions and criteria of calculation process reliability estimation on the basis of which the assumptions for further CO2 separation experimental investigations of a membrane separator working in various conditions were elaborated.
Keywords: CO2 separation, separation parameters, membrane method
Marcin SZEGA
Authentication of measurements in thermal processes by application of data validation and reconciliation (DVR) methodology with the use of fuzzy measurement uncertainties
Results of measurement authentication with the application of data reconsiliation method depend on their assumed uncertainty values. In thermal processes, realized in an industry, the measurement uncertainties are most often determined by using the knowledge based on all available informations concerning possible variations of a measurement result. In many cases, the researchers› experience and occupational knowledge is needed. Presented is an idea to apply in the DVR the measurement uncertainties expressed by fuzzy numbers. Elaborated is the methodology of solving the optimization task with the application of fuzzy measurement uncertainties. Assumed is the value of an optimization task function as the result of an unfuzzy transformation. To illustrate the proposed methodology a calculation example was prepared with the aim to authenticate measurements conducted for two regenerative heat exchangers with a cascade condensate flow. Compared are results of measurement authentication calculations obtained for deterministic and fuzzy measurement uncertainty values. The applied comparison criterion in the form of measurement information relative entropy before and after authentication shows that better results are obtained when using the proposed fuzzy measurement uncertainty methodology.
Keywords: supervision of machines and power equipment operation, measurement of energy carriers thermal parameters, fuzzy measurement uncertainties
Łukasz KOWALCZYK, Witold ELSNER, Stanisław DROBNIAK
Thermoeconomic analysis of supercritical coal fired power plant using RRM method
The paper presents the thermoeconomic analysis for a novel concept of an ultra-supercritical coal-fired steam cycle. The main purpose of this paper was to show basic assumption of RRM method which was used for three different structural configurations of a power unit. The calculations were performed with IPSEpro and RRM methods. Our results confirm the literature data that RRM method is the most suitable one for the energy sector. Additionally this method is one of the most advanced procedures used in the financial analysis. It allows to estimate investment costs for which the revenues provide minimum acceptable cost return for investors. This method was implemented for IPSEpro and MO Excel software. For PEC calculation a new library, called APP_ECO_Lib, was created. Three cases with different structure configurations were analysed. From the viewpoint of thermodynamic the case nr 3 is the most effective system, as the increase of efficiency seems to be sufficient to compensate investment cost associated with structural change. It should be mentioned that some of calculation uncertainty is related with material factors. The analyses have shown that calculations for critical and under-critical steam cycles are sufficiently reliable. However, there is a lack of data for new materials which will be used for design of for ultra-supercritical steam cycle components, that is why calculations for these cases may be biased with some error which is difficult to estimate.
Keywords: thermoeconomic analysis, IPSEpro and RRM methods, material factors
Anna NITKIEWICZ, Monika MUCHA, Waldemar MUSKAŁA, Izabela MAJCHRZAK-KUCĘBA, Dariusz WAWRZYŃCZAK
Methods for monitoring and allocation of SO2 emission rights in the world’s emission trading systems
Programs concerning emissions trading gain respect in the whole world as an effective political tool to reduce emissions levels. The experience in this field shows that effective designing and implementation of emission trading programs allows to achieve the environment goals faster and at lower costs. The aim of this article is to present the models of the SO2 emission trading system functioning in the world and especially of emission allocation rights and their monitoring. In the face of plans relating to introduction of SO2 emission trading system in Poland, the presented here review of the world’s experience in this field may help in creation of a new SO2 trading system. Comprised is the review of the main methods referring to SO2 emission allocation rights and their functioning in the world’s programs aiming at the SO2 emission reduction. Described in detail are four methods of the rights allocation i.e. the historical one, the calorific value, the output value and the emission rate method. Further described are basic elements of numerical infrastructure supporting emissions trading like emission allowance monitoring system, emission monitoring system and emission continuous monitoring system.
Keywords: SO2 emission allowance, monitoring, allocation of emission allowances
Henryk KAPROŃ, Antoni SALIJ
Selected disturbations in turbine condensers operation and their influence on a power unit technical and economic factors
Discussed are examples of disturbances in the work of turbine condensers during their regular operation. Results of these happenings are illustrated by the values of main quality factors of condensers calculated on the basis of indications obtained from a standard measuring equipment located in characteristic places of the installation. Shown are also a power unit basic technical and economic factors having close connection with the parameters characterizing a condenser work. Those mutual indicator relations are used to present the influence of individual disturbances in a condenser work on a power unit economics. The aim of the mentioned examples is to illustrate the relevance of making proper decisions as well as the need of appropriate inspection of such type of an equipment conducted by the continuous operation personnel.
Keywords: condenser, condenser technical factors, thermal flux
Jakub BIENIEK, Aleksandra ŚCIUBIDŁO, Izabela MAJCHRZAK-KUCĘBA
Properties of fly ash derived from coal combustion in air and in oxygen enriched atmosphere in a pilot plant installation Oxy-Fuel CFB 0,1 MW
Presented are results of investigations on physical and chemical properties of fly ash. The fly ash samples derive from the combustion of hard coal in a pilot-scale laboratory 0,1 MWe boiler with circulating fluidized bed (CFB). Selected were ashes derived from combustion in three types of atmospheres: conventional air atmosphere (N2/O2 – 79%:21%), atmosphere with nitrogen replaced by carbon dioxide (CO2/O2 – 79%:21%) and oxygen enriched atmosphere (CO2/O2 – 75%:25%). Investigated was chemical composition of the obtained ashes and the content of the following elements: C, H, S, N, Al, Si, Ca, Fe, Mg, P, K, Mn, Na and Ti was determined. Carried out were also investigations concerning several more physical properties such as thermogravimetrical analysis (TGA) of decomposition, surface properties (average pore volume, micropore volume, BET and Langmuir surface areas) and particle-size distributions. In addition, determined was the loss on ignition (LOI) as well as an analysis of spectra obtained by infrared spectroscopy (FTIR) was carried out.
Keywords: fly ash, physical and chemical properties, surface properties, loss on ignition
Karol WITKOWSKI, Sławomir GRĄDZIEL
Influence of biomass co-combustion on the coefficient of an OP-380 boiler heating surfaces thermal efficiency
Pulverized boilers were once designed mainly to combust pulverized hard coal or lignite. However, recent years have caused that biomass co-combustion in the Polish power industry has become quite common and many boilers have been modernized to biomass co-firing. Calculated is the coefficient of thermal efficiency and the time of full recovery of ash deposits in the RHII’s area of the OP-380 boiler. The analyzed boiler was equipped with a dedicated installation for a biomass direct application. Wood pellets and sunflower husk pellets were co-combusted and sent to the boiler as a fuel with a mass ratio of above 30%. During the unit operation intense accumulation of ash deposits on the reheater tubes was observed and there also occurred some problems with erosion of pipes. Futhermore, evaluated was the impact of biomass on installation’s failure frequency as well as the total costs of failures were divided among those which were triggered by biomass co-combustion and the rest of them.
Keywords: biomass, co-combustion, ash deposit, failure frequency, thermal efficiency coefficient
Anna GAIK, Aleksandra ŚCIUBIDŁO
Physicochemical analysis of the biomass combustion fly ash fractions properties
Presented is the research of a power plant fly ash deriving in 100% from biomass combustion (79% of forest and 21% of agro biomass). Sieve analysis with the use of a dry method and a granulometric analysis by a wet method were done. In nine fractions of fly ashes, obtained by sieve analysis, the loss on ignition (LOI), the percentage share of C, S, N and the content of main elements like Ca, K, Al, Mg, Si, Na, Fe, Ti and Mn were determined. The particle size distribution, obtained during sieve analysis, shows that the biggest share by weight concerns the fractions sized 315 ÷ 500 µm (65,93% wt.) and the lowest the fractions of less than 200 µm (6,24% wt.). As a result of a detailed grain size analysis with the use of a Malvern analyzer, a percentage share increase of ash particles up to a diameter of 549,541 µm was reported while the amount of particles above this size decreased. The results of a precise granulometric analysis carried out for fractions below 250 µm show the biggest share of particles of a diameter between 79,43 µm and 158,49 µm (31,81% wt.). All fly ash fractions were characterized by relatively low losses on ignition from 0.05% to 4.31%, and the highest value was reported for fractions below 125 µm. High percentage content of Ca, K, Mg, Al, Si and low content of Fe, Ti and Mn were also reported. The biggest content of S, C, Ca, Mg, K and Mn occurs mainly in smaller fractions. Furthermore, the results indicate a high content of Si in all fractions with the highest value in a fraction of 500 µm.
Keywords: fly ash, biomass, chemical composition, fly ash fractions
Małgorzata WILK, Aneta MAGDZIARZ, Paweł GARA
Analysis of a wood biomass thermal conversion and a torification process (torrefaction) in particular
The process of a wood biomass sample thermal conversion was investigated in temperatures ranging from an ambient one to 700oC by the method of thermal analysis (TG and DTG curves) in air and argon atmosphere, with special attention paid to 230oC, 260oC and 290oC temperatures charactiristic for the torification process. A wood biomass sample carbonization occurring in a torification process in temperatures of 230oC, 260oC and 290oC and with a 0,5 h, 1,0 h and 1,5 h heating time was investigated in a laboratory electric furnace with an argon atmosphere. It was found that the most efficient carbonization occurred during the torification process conducted for one hour and in the temperature of 260oC.
Keywords: wood biomass, thermal conversion, biomass carbonization
Sławomir RAJCA, Ewald GRZESICZEK, Jerzy TRZESZCZYŃSKI
Assessment and forecast of HP and IP rotors’ lifetime of 13K215 turbines planned to be operated up to 350 000 hours
Operating period of most 200 MW power units is extended beyond its designed lifetime, which is caused by necessity meant as lack of new sources of power in the Polish National Power System. On the basis of positive operational experiences it is assumed that it is possible and safe with no need to replace critical elements, especially HP and IP rotors. That intuitional idea should be verified with both: complex material testing of rotors decommissioned after 250 000 hours of operation and analysis of stress level using Finite Element Method assuming that working conditions are same as recommended by turbine supplier. Taking into consideration the knowledge from testing and calculations the methodology of assessment and forecast of HP and IP rotors’ lifetime, which are planned to be remained in service up to 350 000 hours has been elaborated.
Keywords: 13K215 turbines, WP and SP rotors, technical condition assessment, lifetime prediction
Sławomir SROCZYŃSKI, Artur MERCHUT, Norbert BUCHALIK
Stoker modernization – new construction of fire-bars for travelling grates
FPM S.A. is a mechanical stoker supplier with a long-time tradition. Stoker constructions are being constantly developed and improved by its own design office. In recent years a large number of stokers have been manufactured for the heat, industrial and commercial power engineering sectors. At the same time many new constructional solutions have been introduced improving combustion efficiency of furnace grates. The latest solution, registered at the Patent Office, is the fire-bar construction called „openwork fire-bar”. After a new fire-bars trial batch had been cast, it was installed as a boiler grate in one of the municipal CHP plants. Comprehensive measurements and tests of the boiler grate of the openwork fire-bars type had been carried out and the results were compared with some other grates equipped with the so far used massive fire-bars tested at the same time. The comparison of the obtained results shows many benefits connected with the application of openwork fire-bars in travelling grates.
Keywords: mechanical stokers, new constructional solutions, openwork fire-bars
Rafał KUCZYŃSKI, Bogdan SOBCZAK
Simulator of the Polish Power System – a new tool for training of dispatchers working for the Transmission System Operator
Dispatcher training is a fairly complicated process. One of the tools for a training process realization, both the preliminary one and for the continuous training, applied by the present-day transmission system operators are simulators. PSE SA had made a decision to possess their own simulator and, after 2-years of scrutinizing the problem, they purchased the Aristo simulator (including the service agreement) from the Swedish Transmission System Operator Svenska Krafnett. After the delivery, data concerning our TSO were introduced; among the other problems there was a need to work out, with the use of external applications, a model of a central regulator. Presented are the TSO Simulator abilities, informations about the introduced data and plans of PSE concerning further use of this tool for dispatcher services training.
Keywords: the Polish Transmission System, Transmission System Operator, dispatcher’s training