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Abstract

Generally, the temperature of flue gases at the furnace outlet is not measured. Therefore, a special computation procedure is needed to determine it. This paper presents a method for coordination of the numerical model of a pulverised fuel boiler furnace chamber with the measuring data in a situation when CFD calculations are made in regard to the furnace only. This paper recommends the use of the classical 0-dimensional balance model of a boiler, based on the use of measuring data. The average temperature of flue gases at the furnace outlet tk" obtained using the model may be considered as highly reliable. The numerical model has to show the same value of tk" . This paper presents calculations for WR-40 boiler. The CFD model was matched to the 0-dimensional tk" value by means of a selection of the furnace wall emissivity. As a result of CFD modelling, the flue gas temperature and the concentration of CO, CO2, O2 and NOx were obtained at the furnace chamber outlet. The results of numerical modelling of boiler combustion based on volumetric reactions and using the Finite-Rate/Eddy-Dissipation Model are presented.

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Authors and Affiliations

Bartłomiej Hernik
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Abstract

Power boilers should be characterized by high flexibility in terms of loads, which results from the demand for electricity. In addition to the flexibility of the boiler, it is also important for the boiler to operate under technical minimum conditions while maintaining harmful emissions standards. A boiler operating with a technical minimum should also exhibit a stable combustion process. The paper presents the results of numerical combustion research for the minimum load of the two-pass ultrasupercritical boiler with front wall swirl burners system. The combustion stability for the minimum boiler load of 40% for the three mill system configurations has been demonstrated. Based on the numerical tests carried out in terms of obtaining the most favourable combustion conditions and the emission of harmful substances, the most favourable of them cases was indicated.

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Authors and Affiliations

Bartłomiej Hernik
Wiesław Zabłocki
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Abstract

Construction elements of supercritical power plants are subjected to high working pressures and high temperatures while operating. Under these conditions high stresses in the construction are created. In order to operate safely, it is important to monitor stresses, especially during start-up and shut-down processes. The maximum stresses in the construction elements should not exceed the allowable stress limit. The goal is to find optimum operating parameters that can assure safe heating and cooling processes [1-5]. The optimum parameters should guarantee that the allowable stresses are not exceeded and the entire process is conducted in the shortest time. In this work new numerical method for determining optimum working parameters is presented. Based on these parameters heating operations were conducted. Stresses were monitored during the entire processes. The results obtained were compared with the German boiler regulations - Technische Regeln für Dampfkessel 301.

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Authors and Affiliations

Piotr Duda
Dariusz Rząsa
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Abstract

This paper presents an analysis of the corrosion hazard in the burner belt area of waterwalls in pulverised fuel (PF) boilers that results from low-NOx combustion. Temperature distributions along the waterwall tubes in subcritical (denoted as SUB) and supercritical (SUP) boilers were calculated and compared. Two hypothetical distributions of CO concentrations were assumed in the near-wall layer of the flue gas in the boiler furnace, and the kinetics of the waterwall corrosion were analysed as a function of the local temperature of the tubes. The predicted rate of corrosion of the boiler furnace waterwalls in the supercritical boilers was compared with that of in the subcritical boilers.

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Authors and Affiliations

Marek Pronobis
Rafał Litka
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Abstract

In the paper the methodology of furnace exit gas temperature calculations by using well known normative standard method CKTI is presented. There are shown changes in methodology approach for three editions of it and in additional developments. Furnace exit gas temperature for two stoker grate boilers is calculated. By using described methods, it was possible to determine their effectiveness by comparing with measurements. Knowledge of the furnace exit gas temperature allows to define the division into irradiated and convection surfaces, which has an impact on the design features of the boiler as well as its dimensions and weight.
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Bibliography

[1] Kashnikov S.P., Tsygankov V.N.: Calculation of Boiler Units. In Examples and Problems. Gosenergoizdat, Moscow 1951 (in Russian).
[2] Kuznetsov N.V., Mitor V.V., Dubovsky I.E., Karasina E.S. (Eds.): Thermal Calculation of Boiler Units. Normative Method (2nd Edn.). Energia, Moscow 1973 (in Russian).
[3] Blokh A.G.: Heat Transfer in Steam Boiler Furnaces. Energoatomizdat, Moscow 1984 (in Russian).
[4] Blokh A.G.: Heat Transfer in Steam Boiler Furnaces, Springer Verlag, 1988.
[5] Kagan G.M.: Thermal Calculation of Boilers. Normative Method (3rd Edn.). NPO CKTI, Sankt-Peterburg 1998 (in Russian).
[6] Ye Weijie, Cheng Leming (Eds.): Thermal Calculation Method for Grate-Firing and Fluidized Bed Industrial Boiler, General Methods of Calculation and Design for Industrial Boiler. Standards Press, Bejing 2003 (in Chinese).
[7] Zhang Y.: Theory and Calculation of Heat Transfer in Furnaces. Elsevier, 2016.
[8] Kamenetskii B.Ya.: Applicability of the standard method for calculating heat transfer in furnaces with stokers. Therm. Eng. 53(2006), 2, 138–142.
[9] Kamenetskii B.Ya.: Calculation of heat transfer in boiler furnaces during firing of fuel in a bed. Therm. Eng. 55(2008), 5, 442–445.
[10] EN 12952-15. Water tube boilers and auxiliary installations – Part 15: Acceptance tests.
[11] EN ISO 9001:2015. Quality management systems – Requirements.
[12] EN ISO 14001:2015. Environmental management systems. Requirements with guidance for use.
[13] PN-N-18001:2004. Occupational health and safety management systems – Requirements
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Authors and Affiliations

Łukasz Rutkowski
1
Ireneusz Szczygieł
2

  1. Boilers Manufacturer SEFAKO S.A., Przemysłowa 9, 28-340 Sedziszów, Poland
  2. Silesian University of Technology Institute of Thermal Technology, Konarskiego 22, 44-100 Gliwice, Poland
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Abstract

In this paper an attempt has been made towards the design and evaluation of a solar parabolic trough collector (PTC) system integrated with a conventional oil boiler (COB) to increase the energy utilization effectiveness and reduce the environmental emission of the existing conventional oil boiler in the Kombolcha textile factory, in Ethiopia. The factory uses 8500 ton/annum of heavy fuel oil to generate 26 ton/hour of pressurized hot water at 140°C temperature which causes an increase in greenhouse gas emissions, so the solar parabolic trough collector hot water generation system will be an appropriate solution for this application. Based on the available annual solar radiation, estimates of the solar fraction, solar energy unit price and system pay-back period have been carried out. The proposed system has the potential to save 1055.9 ton/year of fuel oil. The unit cost of PTC solar energy is estimated to be 0.0088 $/kWh and the payback period of the plant is five years. Since the unit price of oil energy (0.0424 $/kWh) is much greater than the unit price of solar energy by a substantial margin (0.033 $/kWh) in Ethiopia, therefore the water heating system by
a solar parabolic trough collector is a feasible alternative to heating by a conventional oil boiler.
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Bibliography

[1] Sharew Anteneh, Solar Energy Assessment in Ethiopia: Modelling and Measurement, Addis Ababa, Ethiopia, vol. 12, iss. 4, pp. 135–145 (2007).
[2] Mekuannint Mesfin, Modelling, Simulation and Performance Evaluation of Parabolic Trough Solar Collector Power Generation System, Addis Ababa University, vol. 12, iss. 4, pp. 65–75 (2009).
[3] Robert A., Parabolic Trough Solar Technology, Encyclopedia of Sustainability Science and Technology, Meyers (ed.) (2012), DOI: 10.1007/978-1-4419-0851-3.
[4] Derese T. Nega, Getachew S. Tibba et al., Software Development for Design, Simulation and Sizing of Parabolic Trough Solar Thermal Power Plant (EthioSolA), Proceedings of the IEEE (2015).
[5] Yahusa I., Rufai Y.A., Tanimu L., Design Construction and Testing of Parabolic Solar Oven, vol. 12, iss. 4 (2016), DOI: 10.4172/2168-9873.1000212.
[6] Alhassan Salami Tijani, Ashraf M.S., Bin Roslan, Simulation Analysis of Thermal Losses of Parabolic trough Solar Collector in Malaysia Using Computational Fluid Dynamics, Procedia Technology 15, pp. 842–849 (2014).
[7] Caiyan Qin, Joong Bae Kim et al., Comparative Analysis of Direct-Absorption Parabolic-Trough Solar Collectors Considering Concentric Nanofluid Segmentation, vol. 44, iss. 5, pp. 4015–4025 (2020), DOI: 10.1002/Er.5165.
[8] Zhiyong Wu, Shidong Li et al., Three-dimensional numerical study of heat transfer characteristics of parabolic trough receiver, Applied Energy, vol. 113, pp. 902–911 (2014).
[9] Hachicha A.A., Rodríguez I., Capdevila R., Oliva A., Heat transfer analysis and numerical simulation of a parabolic trough solar collector, Applied Energy, vol. 111, pp. 581–592 (2013).
[10] Bellos E., Tzivanidis C., Antonopoulos K.A., A Detailed Working Fluid Investigation for Solar Parabolic Trough Collectors, Applied Thermal Engineering, vol. 114, pp. 374–386 (2017).
[11] Badreddine El Ghazzani, Diego Martinez Plaza et al., Thermal Plant Based on Parabolic Trough Collectors for Industrial Process Heat Generation in Morocco, Renewable Energy, vol. 113, pp. 1261–1275 (2017).
[12] Dagim Kebede, Design and analysis of solar thermal system for hot water supply to Minilk hospital new building, Addis Ababa University, vol. 8, iss. 1, pp. 5–14 (2016).
[13] Environmental and Energy Study Institute (EESI), Solar Thermal Energy for Industrial Uses (2011).
[14] El Jai M-C., Chalqi F-Z., A Modified Model for Parabolic Trough Solar Receiver, American Journal of Engineering Research (AJER), e-ISSN: 2320-0847 p ISSN: 2320-0936, vol. 2, iss. 5, pp. 200–211 (2019).
[15] Mutlak F.A.A., Baha T. Chiad, Naseer K. Kasim, Design and Fabrication of Parabolic Trough Solar Collector for Thermal Energy Applications, Republic of Iraq Ministry of Higher Education and Scientific Research University of Baghdad College of Science, vol. 2, iss. 1, pp. 165–175 (2011).
[16] https://www.nationsonline.org/oneworld/map/google_map_ethiopia.htm, accessed 20/11/2018.
[17] Michael Geyer, Eckhard Lüpfert et al., EUROTROUGH Parabolic Trough Collector Developed for Cost Efficient Solar Power Generation, https://www.researchgate.net/publication/282858870 (2015).
[18] Michael Geyer, Eckhard Lupfert et al., EUROTROUGH Parabolic Trough Collector Developed for Cost Efficient Solar Power Generation, 11th SolarPACES International Symposium on Concentrated Solar Power and Chemical Energy Technologies (2002).
[19] Lourdes A. Barcia, Rogelio Peon Menendez et al., Dynamic Modelling of the Solar Field in Parabolic Trough Solar Power Plants, Energies Published; eISSN 1996-1073, vol. 8, no. 12, pp. 13361–13377 (2015).
[20] Holman J.P., Heat Transfer Tenth Edition, Department of Mechanical Engineering Southern Methodist University (eBook) (2010).
[21] Christos Tzivanidis, Evangelos Bellos, The use of parabolic trough collectors for solar cooling – A case study for Athens climate, Case Studies in Thermal Engineering, vol. 8, pp. 403–413 (2016).
[22] Allouhi A., Benzakour Amine M., Kousksou T., Jamil A., Lahrech K., Yearly performance of lowenthalpy parabolic trough collectors in MENA region according to different sun-tracking strategies, Applied Thermal Engineering, vol. 128, pp. 1404–1419 (2018).
[23] Addisu Bekele, Large Scale Application of Solar Water Heating System in Ethiopia, Addis Ababa University (2007).
[24] Yidnekachew Messele, Thermal Analysis, Design and Experimental Investigation of Parabolic Trough Solar Collector, Addis Ababa University (2012).
[25] Duffie J.A., Beckman W.A., Solar Engineering of Thermal Processes, 4th Edition, ISBN: 978-0-470- 87366-3 (2013).
[26] Abhishek Saxena, Ghanshyam Srivastava, Potential and Economics of Solar Water Heating, MIT International Journal of Mechanical Engineering, vol. 2, no. 2, pp. 97–104 (2012).
[27] Dejen Assefa, Techno-Economic Assessment of Parabolic Trough Steam Generation for Hospital, Addis Ababa University, vol. 9, iss. 2, pp. 35–39 (2011).
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Authors and Affiliations

Mustefa Jibril Taha
1
Fiseha Bogale Kibret
2
Venkata Ramayya
3
Balewgize Amare Zeru
4

  1. Control Engineering, Dire Dawa University, Ethiopia
  2. Sustainable Energy Engineering, Kombolcha Institue of Technology (KIoT), Wollo University, P.O.Box 208, Kombolcha, Ethiopia
  3. Sustainable Energy Engineering, Jimma Institue of Technology (JiT), Jimma University, Ethiopia
  4. Thermal Engineering, Jimma Institue of Technology (JiT), Jimma University, Ethiopia
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Abstract

This paper presents a test stand equipped, among others, with two boilers intended for the combustion of solid fuels. The first is a single-fuel boiler designed to burn wood pellets only. The second is a multi-fuel boiler intended for the combustion of mainly hard coal (basic fuel) with the grain size of 0.005–0.025 m. Wood pellets can also be fired in this boiler, which in such a case are treated as a substitute fuel. There is a developed and verified algorithm for the control of the multi-fuel boiler operation in a wide range of loads for the basic fuel. However, for the substitute fuel (wood pellets) there are no documented and confirmed results of such testing. The paper presents selected results of testing performed during the combustion of wood pellets in a multi-fuel automatically stoked boiler. Several measuring series were carried out, for which optimal operating conditions were indicated. These conditions may serve as the basis for the development of the boiler operation control algorithm. A detailed analysis was carried out of the flue gas temperatures obtained at the outlet of the boiler combustion chamber and of the contents of carbon monoxide and oxygen in the boiler flue gases.
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Bibliography

[1] Announcement of the Sejm Speaker of the Republic of Poland on the promulgation of a consolidated text of the Act on renewable energy sources. Journal of Laws – Republic of Poland (Dziennik Ustaw Rzeczypospolitej Polskiej) 2021, Item 610 (in Polish).
[2] Regulation of the Minister of Development and Finance on the requirements for solid-fuel boilers. Journal of Laws – Republic of Poland (Dziennik Ustaw Rzeczypospolitej Polskiej) 2017, Item 1690 (in Polish).
[3] EN 303-5:2021: Heating boilers – Part 5: Heating boilers for solid fuels, manually and automatically stoked, nominal heat output of up to 500 kW – Terminology, requirements, testing and marking.
[4] Poland’s Energy Policy until 2040. Ministry of Climate and the Environment, Appendix to Resolution 22/2021 of the Council of Ministers, 2021 (in Polish).
[5] Commission Regulation (EU) 2019/2146 amending Regulation (EC) 1099/2008 of the European Parliament and of the Council on energy statistics, as regards the implementation of updates for the annual, monthly and short-term monthly energy statistics. OJ L 325, 16.12.2019.
[6] Directive (EU) 2018/2001 of the European Parliament and of the Council on the promotion of the use of energy from renewable sources. OJ L 328, 21.12.2018.
[7] Zima W., Ojczyk G.: Current status and prospects for solid multi-fuel boilers of low power. Rynek Energii 5(2013), 108, 50–56 (in Polish).
[8] Juszczak M., Pałaszynska K., Rolirad K., Janicki M., Szczechowiak E.: Attempt to use additives increasing ash melting point while firing agricultural biomass pellets in order to avoid slag production in the furnace. Ciepłownictwo, Ogrzewnictwo, Wentylacja 48(2017), 8, 320–326 (in Polish).
[9] Ciupek B., Urbaniak R., Judt W.: Experimental research of changes in co, nox and pm concentrations in flue gases during combustion of wood pellets with wheat seeds. Ciepłownictwo, Ogrzewnictwo, Wentylacja 50(2019), 2, 56–61.
[10] Orłowska A., Sroka K.: Changes in legal regulations concerning supplying households with heat. Rynek Energii 140(2019), 1, 38–47.
[11] Zima W., Ojczyk G.: Analysis of combustion of wood pellets as a substitute fuel in a low-power boiler. Arch. Combust. 35(2015), 2, 117–130.
[12] Ziebik A., Stanek W.: Energy effciency – selected thermo-ecological problems. Arch. Thermodyn. 41(2020), 2, 277–299.
[13] https://www.herz-energie.at/pl/ (accessed 6 Sept. 2021).
[14] http://www.ogniwobiecz.com.pl/ (accessed 12 Sept. 2021).
[15] Ecological Safety Mark: Certificate 1035. Inst. Chem. Process. Coal, Zabrze 2009 (in Polish).
[16] https://www.keison.co.uk/ (accessed 17 Aug. 2021).
[17] Kuznetsov N.V., Mitor V.V., Dubovsky I.E., Karasina E.S. (Eds.): Thermal Calculation of Steam Boilers. Normative Method (2nd Edn.). Energia, Moscow 1973 (in Russian).
[18] Rutkowski Ł., Szczygieł I.: Calculation of the furnace exit gas temperature of stoker fired boilers. Arch. Thermodyn. 42(2021), 3, 3–24.


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Authors and Affiliations

Wiesław Zima
1
Grzegorz Ojczyk
2

  1. Cracow University of Technology, Department of Energy, al. Jana Pawła II 37, 31-864 Kraków, Poland
  2. MTHE Modern Technologies in Heating Engineering, Młynska-Boczna 7/2, 31-470 Kraków, Poland
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Abstract

One of the major concerns of the power energy industries is a proper operation of steam power blocks. Pressurized working medium and high temperature cause very high stresses in the construction elements such as collectors, separators or steam valves. They are exposed to sudden temperature and pressure changes that cause high stresses at certain points. Additionally, the cyclic character of loading causes material fatigue, known as low-cyclic fatigue, which may lead to the formation of fracture. Thus, methodologies offered by many companies should ensure reliable and safe operation of steam power blocks. The advanced numerical solutions for determining time-optimum medium temperature changes are presented. They are based on Levenberg-Marquardt and nonlinear programming by quadratic Lagrangian methods. The methods allow us to find parameters for start-up and shut-down operation that can reduce total stresses to limits governed by European regulations. Furthermore, the heating and cooling operations are conducted in a shortest time possible.
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Authors and Affiliations

Dariusz Rząsa
Piotr Duda
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Abstract

Modern supercritical power plants operate at very high temperatures and pressures. Thus the construction elements are subjected to both high thermal and mechanical loads. As a result high stresses in those components are created. In order to operate safely, it is important to monitor stresses, especially during start-up and shut-down processes. The maximum stresses in the construction elements should not exceed the allowable stresses that are defined according to boiler regulations. It is important to find optimum operating parameters, that can assure safe heating and cooling processes. The optimum parameters define temperature and pressure histories that can keep the highest stresses within allowable limit and reduce operation time as much as possible. In this paper a new numerical method for determining optimum working fluid parameters is presented. In this method, properties of steel can be assumed as constant or temperature dependent. The constant value is taken usually at the average temperature of the operation cycle. For both cases optimal parameters are determined. Based on these parameters start-up operations for both cases are conducted. During entire processes stresses in the heated element are monitored. The results obtained are compared with German boiler regulations - Technische Regeln fur Dampfkessel 301.

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Authors and Affiliations

Dariusz Rząsa
Piotr Duda
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Abstract

Heating surfaces in power boilers are exposed to very high heat flux. For evaporator protection against overheating, internally helically ribbed tubes are used. The intensification of the heat transfer and the maintenance of the thin water layer in the intercostal space, using ribbed tubes, enables better protection of the power boiler evaporator than smooth pipes. Extended inner surface changes flow and thermal conditions by influencing the linear pressure drop and heat transfer coefficient. This paper presents equations that are used to determine the heat transfer coefficient. The results of total heat transfer, obtained from CFD simulations, for two types of internally ribbed and plain tubes are also presented.

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Authors and Affiliations

Karol Majewski
Sławomir Grądziel
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Abstract

Describing the gas boiler fuel consumption as a time series gives the opportunity to use tools appropriate for the processing of such data to analyze this phenomenon. One of them are ARIMA models. The article proposes this type of model to be used for predicting monthly gas consumption in a boiler room working for heating and hot water preparation. The boiler supplies heat to a group of residential buildings. Based on the collected data, three specific models were selected for which the forecast accuracy was assessed. Calculations and analyses were carried out in the R environment using “forecast” and “ggplot2” packages. A good quality of the obtained forecasts has been demonstrated, confirming the usefulness of the proposed analytical tools. The article summary also indicates for what purposes the forecasts obtained in this way can be used. They can be useful for diagnosing the correct operation of a heat source. Registering fuel consumption at a level significantly deviating from the forecast should be a signal to immediately diagnose the boiler room and the heat supply system and to explain the reason for this difference. In this way, it is possible to detect irregularities in the operation of the heat supply system before they are detected by traditional methods. The gas consumption forecast is also useful for optimizing the financial management of the property manager responsible for the operation of the boiler room. On this basis, operating fees or financial operations with the use of periodic surplus capital may be planned.

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Authors and Affiliations

Grzegorz Bartnicki
Bogdan Nowak
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Abstract

The changes in the domestic solid fuel market (including forecasted increases in the fuel prices) and the growing requirements related to actual environmental standards, result in increased interest in renewable energy sources, such as biomass, wind and solar energy. These sources will allow to achieve reduction in the CO2 emission, and consequently – avoid environmental costs after 2020. Therefore, the development of distributed energy systems, based on the use of biomass boilers, gas boilers and high efficiency combined heat and power units, will enable the fulfillment of current standards in the field of energy efficiency and emission of pollutants to the atmosphere. It should be emphasized that the actions taken to reduce emissions (e.g. anti-smog act) will contribute to reducing coal consumption in the municipal and housing sector (households, agriculture and other customers) in favor of biomass and other renewable energy sources. The article reviews selected biomass technologies:

- fluidized, dust and grate boilers,

- straw-fired boilers,

- cogeneration systems powered by biomass,

- torrefaction and biomass carbonisation.

The mentioned technologies are characterized by a high potential of in the field of dynamic development and practical application in the coming years. Thus, they can improve difficult situation in the distributed energy sector with a capacity up to 50 MW.

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Authors and Affiliations

Tomasz Mirowski
Eugeniusz Mokrzycki
Mariusz Filipowicz
Krzysztof Sornek
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Abstract

Low emission has a significant impact on air quality in Poland. Low sources are found which lead to high concentrations of pollutants in the area inhabited by humans. The effects of low emissions on health and life in the polluted areas (Małopolska, Silesia) are conducive to radical decisions regarding the quality of solid fuels and their combustion facilities. At present, local anti-smuggling laws have been introduced in the two provinces banning the burning of the most emitting fuels such as mules, flotoconcentrates and lignite. Regional EU-funded programs for the use of renewable energy sources (RES) and energy efficiency improvement will transition to the implementation phase of the approved projects as of 2017. This is expected to significantly reduce energy consumption for heating buildings and replacing old boilers and automatic furnaces with low-emission heating devices. In the case of households, proving that the residential building has adequate energy efficiency characteristics is necessary in order to receive co-financing for replacing an old solid fuel boiler with a new low-emission boiler,. The paper will present the current situation on the regulation of the fuel market in the household and small–scale consumer sector and the proposal for changes to the law on monitoring and control of solid fuel quality. Another important issue will be significant changes in heating up to 500 kW, proposed by the Ministry of Development in October 2016. The proposed regulation precedes the implementation of the Ecodesign Directive, which will come into effect as of 2022 for room heaters and heating furnaces up to 500 kW for solid fuels. All these actions will help reduce low emissions and improve energy efficiency.

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Authors and Affiliations

Tomasz Mirowski
Renata Maczuga
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Abstract

The relevance of this study is explained by the growing interest in increasing heat transfer by the development of high-performance thermal systems. Increasing the thermal characteristics of heat-exchanger systems is necessary for the efficient use of an energy source. The purpose of this study is to review the existing methods of heat-transfer intensification and examine the mathematical model of such an increase in efficiency when using petal turbulators. This study is based on a high-quality, reliable combination of proven theoretical methods (analysis, synthesis, concretization, generalization, modelling), and empirical methods. It is the introduction of turbulators into the flow channel that is one of the best methods of increasing passive heat exchange through such advantages as ease of manufacture and operation in combination with low operating and production costs. This study contains both passive and active methods of heat-exchange intensification that have been extensively investigated over the past decade. For this purpose, the newest studies of mainly authors from other countries were used, their detailed analysis was conducted and the results were summed up. In addition, a mathematical model of increasing the thermal efficiency of convective heating surfaces in a bundle of smooth pipes using petal turbulators was investigated, the results of which were tested on an experimental installation. The paper may interest a circle of readers interested in the problem of improving the thermal characteristics of heat exchangers, including researchers, teachers and students of higher educational institutions in the field of heat-power engineering.
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Authors and Affiliations

Jiyenbeck Sugirov
1
Bibigul Atshybayeva
2
Marzhan Suimenova
1
Kulanda Shaikhiyeva
1
Gulbanu Yesbolay
1

  1. Department of Construction Engineering, Caspian University of Technology and Engineering named after Sh. Yessenov, Republic of Kazakhstan
  2. Department of Energy and Transport, Caspian University of Technology and Engineering named after Sh. Yessenov, Republic of Kazakhstan
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Abstract

The energy obtained from biomass in the global balance of energy carriers is the largest source among all RES. It should be borne in mind that the share of biomass as an energy carrier in the total balance is as much as 14%. The basic sources of renewable energy used in Poland are the wind power industry and biomass. Organic chemical compounds are the source of chemical energy for biomass. The biomass can be used in a solid form (wood, straw) or after being converted to liquid (alcohol, bio-oil) or gas (biogas) form.

Pellets, meaning, the type of fuel of natural origin created from biomass compressed under high pressure without the participation of any chemical adhesive substances are recognized as the most common and available grades of biomass. Wood pellets manufactured from sawdust, shaving, or woodchips are the most popular type of pellets on the market. Fuel created in the form of granules is very dense and can be manufactured with low humidity content, which translates into an exceptionally high burn efficiency.

The authors of this article burned agro pellets from Miscanthus giganteus without additives and with solid catalyst and conducted a series of tests that determine the impact of boiler settings (blast power, time of feeding, chimney draft) on the process of burning fuel in real conditions. A solid catalyst was used to improve combustion conditions in one of the fuels. The catalyst burns carbon monoxide and reduces nitrogen oxides. The results in the form of observation of selected parameters are summarized in the table.

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Authors and Affiliations

Tomasz Mirowski
Marta Jach-Nocoń
Iwona Jelonek
ORCID: ORCID
Adam Nocoń
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Abstract

Wood pellets, commonly referred to as biomass fuel, are increasingly used in heating and district heating in the European Union countries, including Poland. Their use in class 5 and/or Ecodesign boilers enables an individual consumer to use energy from renewable sources, reduce the environmental burden by reducing the emission of harmful compounds, and provides a sense of comfort by automating the boiler system. The article presents the current situation in the global wood pellet market, describes the basic quality standards applicable to this fuel during production, and indicates the difficulties in the implementation of programs co-financing the replacement of obsolete coal-fired boilers with automatic class 5 biomass-fired boilers. The research presented in this article is focused on the presence of contaminants in the DIN Plus, EN Plus, and A1 pellets, as well as in non-certified pellets. The analysis has shown that the use of wood pellets containing prohibited substances negatively affects boiler operation and contributes to the formation of slag and the emission of harmful compounds, making the discussed fuel non-ecological.

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Authors and Affiliations

Marta Jach-Nocoń
Adam Nocoń
Tomasz Mirowski
Iwona Jelonek
ORCID: ORCID
Zbigniew Jelonek
ORCID: ORCID
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Abstract

This paper presents the development of a multiphase aerodynamic reactor designed for multi-component systems, focusing on precise catalyst dosing in the combustion chamber. The study aims to underscore the significance of this work by emphasizing the critical role of optimized operational conditions in enhancing the transportation of the modifier for combustion processes. Through comprehensive numerical simulations and experimental tests, this research explores the impact of parameters such as flow rates of the dosed substance and air, dosing nozzle outlet diameter, and conduit diameter on the flow rate and trajectory of the transported modifier. The findings highlight the importance of a minimum droplet diameter of 30 μm, preferably 50 μm, for proper delivery to the combustion chamber. This study not only identifies key differences between analyzed structures but also emphasizes the crucial role of these operational parameters in achieving optimal conditions for modifier transport.
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Authors and Affiliations

Marek Ochowiak
1 2
Zdzisław Bielecki
2 3
Andżelika Krupińska
1
Sylwia Włodarczak
1
Magdalena Matuszak
1

  1. Department of Chemical Engineering and Equipment, Poznan University of Technology, Pl. M. Sklodowska-Curie 5, 60-965 Poznan, Poland
  2. Kuncar S.A., Pszczyńska 167C, 43-175 Wyry, Poland
  3. Department of Automatic Control and Robotics, Silesian University of Technology, Akademicka 2A Str., 44-100 Gliwice, Poland
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Abstract

This paper presents the results of developing a methodology for assessing and predicting the technical condition of boiler plants and steam turbines. The proposed method is based on generalized experimental data on failures to predict the damage of the principal elements and components of thermal power plants by Monte-Carlo simulation. The proposed method considers the complexity of technological processes, turnaround time, failure rate, and condition of the residual metal life. It allows developing approaches to assessing each element’s safety to obtain a reliable and representative sample of failure statistics to reliability assessment of boilers and steam turbines of thermal power plants. According to the results, the probability of failure operation of steam boilers and turbines is 0.037 in the 100 MW conditions. The obtained results can be used to create predictive models that provide approaches to prolonging the operational state of elements of boiler plants and steam turbines of thermal power plants. It can be used in the implementation of projects of digital energy systems for monitoring and diagnostics of the main power equipment of thermal power plants.
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Authors and Affiliations

Makhsud Mansurovich Sultanov
1
Stepan Anatolyevich Griga
2
Maksim Sergeevich Ivanitckii
1
Anatoly Alekseevich Konstantinov
1

  1. National Research University MPEI, Krasnokazarmennaya 17, Moscow, 111250 Russia
  2. PJSC “Mosenergo”, Vernadsky Avenue 101/3, Moscow, 119526 Russia
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Abstract

This article presents results of research concerning the possibility of reducing the level of toxic nitric oxides (NOx) emission to the atmosphere. The research has been conducted on DKVR 20-13, PTVM-50 and DE 25-14 gas boilers. The complex character of this issue requires individual consideration regarding each boiler configuration. Each case requires consideration of characteristics and details of all elements constituting the boiler-furnace unit. The main problem was to establish the reference level to which the reduction of nitric oxides occurs. The actual maximum emission of nitric oxides was assumed as this level. It was verified with the maximum allowable emission of nitric oxides for each boiler. Three levels of the potential influence of emission on the atmosphere have been taken into account. This experimental research allowed for proposing an effective method, which led to reducing nitric oxides emission by around 30%.

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Authors and Affiliations

Sylwia Janta-Lipińska
1
Alexander Shkarovskiy
1 2

  1. Koszalin University of Technology, Faculty of Civil Engineering, Environmental and Geodetic Sciences, Poland
  2. Saint Petersburg State University of Architecture and Civil Engineering, Faculty of Environmental Engineering and Municipal Services, Russia
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Abstract

Results of fly ashes from combustion of hard coal and co-combustion of alternative fuel (SRF) with coal in the stoker boiler WR-25 type studies have been shown. Samples of fly ashes were acquired during industrial combustion tests of hard coal and blend of coal with 10% SRF. The scope of comparative research included: chemical composition, contents of combustible parts and trace elements and also of microscopic analysis. The specific surface area SBET was established and tests of water extract were conducted. Chemical composition of mineral substance of both studied ashes is similar. Main ingredients are: SiO2, Al2O3, Fe2O3 and CaO. Fly ash from co-combustion of SRF with coal in a stoker boiler is characterized by high contents of combustible parts (on 30% level), higher than ash from hard coal combustion. Both tested ashes are characterized by specifi c surface area SBET on the level of 8–9 m2/g. In porous structure mesopores are dominant (>60%), and their volume is higher for fly ash from co-combustion of SRF with coal. Fly ash from co-combustion of waste is characterized by high contents of heavy metals. Nevertheless these metals and also other pollutants do not show leachability exceeding acceptable values for wastes different than hazardous. The microscopic structure of fly ashes from combustion of hard coal and co-combustion of alternative fuel studies showed crucial differences, especially in reference to organic material. Presented research results have shown that fly ash from co-combustion of SRF with coal in a stoker boiler can obtain the status of non-hazardous waste.

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Authors and Affiliations

Ryszard Wasielewski
1
Małgorzata Wojtaszek
1
Agnieszka Plis
1

  1. Institute for Chemical Processing of Coal, Poland
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Abstract

The emission of dust from coal fired furnaces introduces a lot of contamination into the environment, including dangerous metal compounds, which occur as trace elements in hard and brown coal. After the coal is burnt, they are contained in the grains of respirable dust, which creates health hazard. The results of investigations into the distribution of several trace elements in granular composition of ash emitted from CFB boilers used in coal-fired heat and power station are presented. The research material was taken by means of a cascade impactor, enabling a different granulometrie fraction to be separated from a stream of dust that penetrated the electrofilter. The CP-AES method (inductively coupled plasma atomic emission spectroscopy) was used to determine trace elements after prior mineralization of samples by microwave method. The Authors presented the results of measurements and analyses, determining the ranges of trace elements' occurrence in dust, characterizing the distribution in PM,, PM25 and PM10 granulometrie fractions and determining the emission factors.
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Authors and Affiliations

Jan Konieczyński
Katarzyna Stec

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