Search results

Filters

  • Journals
  • Authors
  • Keywords
  • Date
  • Type

Search results

Number of results: 63
items per page: 25 50 75
Sort by:
Download PDF Download RIS Download Bibtex

Abstract

The problem presented in this paper refers to the concepts applied to the design of supercritical steam turbines. The issue under the investigation is the presence of a cooling system. Cooling systems aim to protect the main components of the turbines against overheating. However the cooling flows mix with the main flow and modify the expansion line in the steam path. This affects the expansion process in the turbine and changes the performance when compared to the uncooled turbine. The analysis described here investigates the range of the influence of the cooling system on the turbine cycle. This influence is measured mainly through the change of the power generation efficiency. The paper explains the approach towards the assessment of the cooling effects and presents results of the modeling for three supercritical steam cycles.

Go to article

Authors and Affiliations

Wojciech Kosman
Download PDF Download RIS Download Bibtex

Abstract

The paper presents an analysis of relations describing entropy generation in a condenser of a steam unit. Connections between entropy generation, condenser ratio, and heat exchanger effectiveness, as well as relations implied by them are shown. Theoretical considerations allowed to determine limits of individual parameters which describe the condenser operation. Various relations for average temperature of the cold fluid were compared. All the proposed relations were verified against data obtained using a simulator and actual measurement data from a 200 MW unit condenser. Based on data from a simulator it was examined how the sum of entropy rates, steam condenser effectiveness, terminal temperature difference and condenser ratio vary with the change in the inlet cooling water temperature, mass flow rate of steam and the cooling water mass flow rate.
Go to article

Authors and Affiliations

Rafał Laskowski
Maciej Jaworski
Adam Smyk
Download PDF Download RIS Download Bibtex

Abstract

The paper deals with the wet steam flow in a steam turbine operating in a nuclear power plant. Using a pneumatic and an optical probe, the static pressure, steam velocity, steam wetness and the fine water droplets diameter spectra were measured before and beyond the last turbine low-pressure stage. The results of the experiment serve to understand better the wet steam flow and map its liquid phase in this area. The wet steam data is also used to modify the condensation model used in computational fluid dynamics simulations. The condensation model, i.e. the nucleation rate and the growth rate of the droplets, is adjusted so that results of the numerical simulations are in a good agreement with the experimental results. A 3D computational fluid dynamics simulations was performed for the lowpressure part of the turbine considering non-equilibrium steam condensation. In the post-processing of the of the numerical calculation result, the thermodynamic wetness loss was evaluated and analysed. Loss analysis was performed for the turbine outputs of 600, 800, and 1100 MW, respectively.
Go to article

Bibliography

[1] Walters P.T., Skingley P.C.: An optical instrument for measuring the wetness fraction and droplet size of wet steam flow in LP turbines. In: Proc. Conf. on Steam Turbines for the 1980s, Vol. 12, London, 9–12 Oct. 1979, C141, 337–348.
[2] Kleitz A., Laali, A.R., Courant J.J.: Fog droplet size measurement and calculation in wet steam turbines. In: Proc. Int. Conf. on Technology of Turbine Plant Operating in Wet Steam (J.M. Mitchell, Ed.), London, 11–13 October 1988, 201– 206.
[3] Petr V., Kolovratník M.: Modelling of the droplet size distribution in LP steam turbine. In: Proc. 3rd Eur. Conf. on Turbomachinery – B, Fluid Dynamics and Thermodynamics, London, 2–5 March 1999, 771–782.
[4] Starzmann J., Schatz M., Casey M.V., Mayer J.F., Sieverding F.: Modelling and validation of wet steam flow in a low pressure steam turbine. In: Proc. ASME Turbo Expo 2011, Vancouver, June 6–10, 2011, GT2011-45672, 2335–2346.
[5] Hideaki S., Tabata S. Tochitani N., Sasao Y., Takata R., Osako M.: Investigation of moisture removal on last stage stationary blade in actual steam turbine. In: Proc. ASME Turbo Expo 2020, virtual, online, Sept. 21–25, 2020, GT2020-14831.
[6] Grübel M., Starzmann J., Schatz M., Eberle T., Vogt D.M., Sieverding F.: Two-phase flow modeling and measurements in low-pressure turbines – Part I: numerical validation of wet steam models and turbine modeling. J. Eng. Gas Turbines Power 137(2015), 4, 042602 (11), GTP-14-1442.
[7] Starzmann J., Hughes F. R., White, A., et al.: Results of the International Wet Steam Modelling Project. In: Proc. Wet Steam Conference. Prague, Sept. 12–14, 2016.
[8] Fendler Y., Dorey J.M., Stanciu M., Lance M., Léonard O.: developments for modeling of droplets deposition and liquid film flow in a throughflow code for steam turbines. In: Proc. ASME Turbo Expo 2012, Copenhagen, June 11–15, 2012, GT2012-68968, 537–547.
[9] Gyarmathy G.: Grundlagen einer Theorie der Nassdampfturbine. PhD thesis, ETH Zurich, Juris-Verlag, Zurich 1962.
[10] Laali A.R.: A new approach for assessment of the wetness losses in steam turbines. In Proc. IMechE Conf. Turbomachinery – Latest Developments in a Changing Scene, London, March, 1991, 155–166.
[11] Wróblewski W, Chmielniak T., Dykas S.: Models for water steam condensing flows. Arch. Thermodyn. 41 (2020), 4, 63–92.
[12] Petr V., Kolovratník M.: Wet steam energy loss and related Baumann rule in low pressure steam turbines. P. I. Mech. Eng. A-J. Pow. 228(2014), 2, 206–215.
[13] Holmberg H., Ruohonen P., Ahtila P.: Determination of the real loss of power for a condensing and a backpressure turbine by means of second law analysis. Entropy 11 (2009), 4, 702–712.
[14] Gardzilewicz A.: Evaluating the efficiency of low pressure part of steam turbines based on probing measurements. Trans. Inst. Fluid-Flow Mach. 135(2017), 41–56.
[15] Míšek T., Kubín Z.: Static and dynamic analysis of 1 220 mm steel last stage blade for steam turbine. Appl. Comput. Mech. 3(2009), 1, 133–140.
[16] Luxa M. Safarík P., Synác J., Rudas B.: High-speed aerodynamic investigation of the midsection of a 48” rotor blade for the last stage of steam turbine. In: Proc: 10th Eur. Conf. on Turbomachinery Fluid Dynamics and Thermodynamics, ETC10, Lappeenranta, Apr. 15–19, 2013, ETC2013-116.
[17] Finzel C., Schatz M., Casey M.V., Gloss D.: Experimental investigation of geometrical parameters on the pressure recovery of low pressure steam turbine exhaust hoods. In: Proc. ASME Turbo Expo 2011, Vancouver, June 6–10 2011, GT2011- 45302, 2255–2263.
[18] Jones M., Crossland R.: performance improvements of nuclear power plants by the application of longer LP last stage blades and advanced design techniques. In: ASME Power Conf., Baltimore, June 28–31, 2014; POWER2014-32072, V001T04A002.
[19] Hoznedl M., Kolovratník M., Bartoš O., Sedlák K., Kalista R., Mrózek L.: Experimental research on the flow at the last stage of a 1090 MW steam turbine. P. I. Mech. Eng. A-J. Pow 232(2018), 5, 515–524.
[20] Štastný M.: Flow field in the last steam turbine stage. In: Proc. 7th Eur. Conf. on Turbomachinery Fluid Dynamics and Thermodynamics , Euroturbo 7, Athens, March 5–9, 2007, 867–876.
[21] Kolovratník M., Bartoš O.: CTU optical probes for liquid phase detection in the 1000 MW steam turbine. In: Proc. EFM14 – Experimental Fluid Mechanics 2014, EPJ Web Conf. 92(2015), 02035.
[22] Brüggemann C., Schatz M., Vogt D.M., Popig F.: A numerical investigation of the impact of part-span connectors on the flow field in a linear cascade. In: Proc.ASME Turbo Expo 2017, Charlotte, June 26–30, 2017, GT2017-63359, V02AT40A005.
[23] Radnic T., Hála J., Luxa M., Šimurda D., Fürst J., Hasnedl D., Kellner, J.: Aerodynamic effects of tie-boss in extremely long turbine blades. ASME J. Eng. Gas Turbines Power. 140(2018), 11: 112604, GTP-17-1218.
[24] Häfele M. Traxinger C., Grübel M., Schatz M., Vog D.M., Drozdowski R.: Experimental and numerical investigation of the flow in a low-lressure industrial steam turbine with part-span connectors. In: Proc. ASME Turbo Expo 2015: Montreal. June 15–19, 2015, GT2015-42202, V008T26A005.
[25] Young J.B.: Spontaneous condensation of Steam in Supersonic Nozzles. 1980STIN...8113306Y, Whittle laboratory, Cambridge University, 1980
[26] Gerber A.G. Kermani M.J.: A pressure based Eulerian–Eulerian multi-phase model for non-equilibrium condensation in transonic steam flow. Int. J. Heat Mass Tran. 47(2004), 10–11, 2217–2231.
[27] Hill P.G.: Condensation of water vapour during supersonic expansion in nozzles. J. Fluid Mech. 25(1966), 3, 593–620.
[28] Ansys CFX. https://www.ansys.com/products/fluids/ansys-cfx (accessed 5 March 2021).
[29] The International Association for the Properties of Water and Steam. Revised Release on the IAPWS-97 Industrial Formulation 1997 for the Thermodynamic Properties of Water and Steam. http://www.iapws.org/relguide/IF97-Rev.html (accessed 15 Sept. 2020).
[30] Sova L., Jun G., Štastný M.: Modifications of steam condensation model implemented in commercial solver. AIP Conf. Proc. 1889(2017), 020039-1–020039-8.
[31] Petr V., Kolovratník M.: Heterogeneous effects in the droplet nucleation process in LP steam turbines. In: Proc. 4th Eur. Conf. on Turbomachinery Flud Dynamics and Thermodynamics (G. Bois, R. Decuypere, F. Martelli, Eds.), Firenze, 2001, 783–792.
[32] Baumann K.: Some recent developments in large steam turbine practice. J. Inst. Electr. Eng., 59(1921), 565–623.
[33] Moore M.J.: Gas dynamics of wet steam and energy losses in wet-steam turbines. In: Two-Phase Steam Flow in Turbines and Separators (M.J. Moore, C.H. Sieverding, Eds.). Hemisphere, Washington 1976, 59–126.
Go to article

Authors and Affiliations

Gukchol Jun
1 2
Michal Kolovratník
2
Michal Hoznedl
1

  1. Czech Technical University in Prague, Technická 4, 160 00, Prague, Czech Republic
  2. Doosan Škoda Power s.r.o., Tylova 1/57, 301 28, Pilsen, Czech Republic
Download PDF Download RIS Download Bibtex

Abstract

The purpose of the article was to characterize the international steam coal market based on the latest available data. The information goes back to the first half of 2018. The article focuses on the description of the three largest exporters and importers of steam coal. Representatives in these categories were selected using the latest global statistics on 2017. In 2017, global production of steam coal amounted to 5.68 billion tons and exceeded production in 2016 by 4%. For several years, invariably the world’s leading exporters of steam coal are: Indonesia, Australia and Russia. In total, these three countries in 2017 supplied 73% of steam coal to the international market. However, for the 46% of global steam coal imports (data for 2017), three Asian countries are responsible: China, India and Japan. For each of the six listed countries (i.e. for: three major global exporters and three major global importers), the paper presents volumes related to coal production, export or import. The directions of deliveries or major coal exporters to a given country were also included. At the end of the article, the price situation was presented, as it appeared in the first half of 2018 on the European and Asian markets.

Go to article

Authors and Affiliations

Katarzyna Stala-Szlugaj
Download PDF Download RIS Download Bibtex

Abstract

This paper analyses the influence of three different ring-type inlet duct geometries on the performance of a small 1 MW backpressure steam turbine. It examines the efficiency and pressure drop of seven turbine variants, including four spiral inlet geometries and three stages with a mass flow rate around 30 t/h. A one-pipe and two-pipe inlets are analysed from aerodynamical point of view, taking into account stator and rotor blades in three stages without the outlet. An outlet is added to the best variant. Also analysed is the occurrence of vortices in the inlets of the studied variants 1–7 as well as the efficiency, drop pressure, turbine power and mass flow. Finally, the best inlet for a 1 MW steam turbine is suggested.
Go to article

Bibliography

[1] Bellucci J., Rubechin F., Arnone A.: Modeling partial admission in control stages of small steam turbines with CFD. In: Proc. ASME Turbo Expo, June 11-15 2018 Oslo, GT2018-76528, 2018.
[2] Lampart P., Szymaniak M., Rzadkowski R.: Unsteady load of partial admission control stage rotor of a large power steam turbine. In: Proc. ASME Turbo EXPO 2004, Power for Land, Sea and Air, June 14–17, 2004, Vienna, ASME GT-2004- 53886, 2004.
[3] Van den Braembussche R.A.: Flow and loss mechanisms in volutes of centrifugal pumps. Educational Notes. In: Design and Analysis of High Speed Pumps (12-1–12- 26). Educational Notes RTO-EN-AVT-143, Neuilly-sur-Seine, RTO, 2006 (available from: http://www.rto.nato.int/abstracts.asp).
[4] Drexler C.: Strömungsvorg ange und Verlustanteile in ungleichformig beaufschlagten Turbinenstufen. PhD thesis, RWTH Aachen University, Aachen 1996. Computational fluid dynamics analysis of 1 MW steam turbine inlet geometries 55
[5] Traupel W.: Thermische Turbomaschinen (4th Edn.). Springer, 2001.
[6] Kovats A.: Effect of non-rotating passages on performance of centrifugal pumps and subsonic compressors. In: Proc. Winter Annual Meeting, New York 1979.
[7] Lüdtke K.: Centrifugal process compressors – radial vs. tangential suction nozzles. In: ASME Paper 85-GT-80, 1985.
[8] Sievert R.: Analyse der Einflussparameter auf die Strömung im Eintritt von Niederdruck-Dampfturbinen. PhD thesis, Ruhr-Universität Bochum, Bochum 2006 (in German).
[9] Maier W.: Inlet casing for a turbine. US Patent US5927943A, 1999.
[10] Škach R., Uher J.: Spiral Inlets for Steam Turbines. AIP Conf. Proc. 1889, 020038, 2017.
[11] Hecker S., Rohe A., Stoff H.: Steam turbine inlet geometry from a structural and fluid dynamics point of view. In: Proc. ASME Turbo Expo 2012, GT2012-68678, 2012, 487–495.
[12] Gao K., Wang C., Xie Y., Zhang D.: Effects of inlet chamber structure of the control stage on the unsteady aerodynamic force. In: Proc. ASME Turbo Expo, Oslo, June 11–15 2018, GT2018-76632, 2018.
[13] Engelmann D., Schram A., Polklas T., Mailch P.: Losses of steam admission in industrial steam turbines depending on geometrical parameters. In: Proc. ASME Turbo Expo, Dusseldorf – Oslo, June 16-20 2014, GT2014-25172, 2014.
[14] Dejch M.,E., Filippov G.A., Lazarev L.Ja.: Collection of Profiles for Axial Turbine Cascades. Machinostroienie, Moscow 1965 (in Russian).
[15] Kietlinski K., Czerwinski P.: Retrofit of 18K370 steam turbine on the units 7–12 at Belchatow Power Plant. Arch. Energ. XLI(2011), 3-4, 77–96.
[16] Ansys CFX, Release 18.2.
[17] Ansys Meshing, Release 18.2
[18] Ansys TurboGrid, Release 18.2
[19] Ansys DesignModeller, Release 18.2
[20] Ansys CFX, Release 18.2, CFX documentation. Ansys, Inc.
Go to article

Authors and Affiliations

Arkadiusz Koprowski
1
Romuald Rzadkowski
1 2

  1. Institute of Fluid Flow Machinery Polish Academy of Sciences, Fiszera 14, 80-952 Gdansk, Poland
  2. Air Force Institute of Technology, Ksiecia Bolesława 6, 01-494 Warsaw, Poland
Download PDF Download RIS Download Bibtex

Abstract

Problems related to power control of low power-output steam turbines are analyzed. These turbines are designed to operate in distributed power generation systems. Principles of automatic control involving a single control valve are presented on the basis of experience gathered with high power-output turbines. Results of simulations of power control for a low power-output turbine are discussed. It has been proven that closing of the control system and an application of a power controller (of optimally selected parameters) improves the object dynamics (shortening of the transition period). At the same time, a lack of such optimization can results in occurrence of undesirable phenomena such as: overshoot in the generator power characteristics, elongation of the response time to disturbance or overshoot of turbine control valves.
Go to article

Bibliography

[1] Karczewski J., Szuman P.: Electrohydraulic Ccontrol of Real Power of Turbosets in the Power and Electricity Generation System Control. Monografie 6. Wydawn. Inst. Energ., Warszawa 2020 (in Polish).
[2] Domachowski Z.: Automatic Control of Thermal Turbosets. Wydawn. PG, Gdansk 2014 (in Polish).
[3] Janiczek R.: Operation of Steam Powerplants. WNT, Warszawa 1992 (in Polish).
[4] Pawlik M., Strzelczyk F.: Power Plants. WNT, Warszawa 2009 (in Polish).
[5] Chmielniak T.: Power Generation Technologies. PWN, Warszawa 2021 (in Polish).
[6] Kryłłowicz W., Szwaja S.: A lowpower-output steam turbine in a system with a heat recovery boiler. Project rep. POIG 01.03.01-26-021/12, Czestochowa 2015 (in Polish).
[7] Gundlach W.: Turbomachinery. PWN, Warszawa 1970 (in Polish). [8] Karczewski J., Szuman P.: Scilab. Modelling and Simulation of Control System Operation. Nakom, Poznan 2019 (in Polish).
[9] Karczewski J.: Coordination of loading of boiler and turbine systems in an electricpower unit. IEEE Catalog Number CFP19H21-ART.: ISBN: 978-1-7281-2053-9.
[10] Karczewski J., Pawlak M.: Power control problems of units co-burning biomass. Arch. Energ. XLI(2011), 3–4, 29–39.
[11] Karczewski J., Pawlak M., Szuman P., Wasik P.: Assessment of availability of the power unit participating in the regulation of the electrical power system. Arch. Energ. XL(2010), 1–2, 89–102.
[12] Karczewski J., Szuman P.: Testing of the power unit control systems using power unit and its parts simulation model. Elektronika (2018), 11 (in Polish).
[13] Karczewski J., Szuman P.: Testing of the power unit control systems using power unit simulator. Elektronika (2017), 11 (in Polish).
[14] Karczewski J., Szuman P.: Power unit work optimization based on simulation of various control system configurations. Prace Inst. Elektrotechn. 270(2015) (in Polish).
[15] Karczewski J., Szuman P.: Simulation of various control system configuration of power units. Elektronika (2015), 12 (in Polish).
Go to article

Authors and Affiliations

Władysław Kryłłowicz
1
Jacek Karczewski
2
Paweł Szuman
2

  1. Lodz University of Technology, Institute of Turbomachinery, Wolczanska 217/221, 93-003 Lodz, Poland
  2. Institute of Power Engineering, Mory 8, 01-330 Warsaw, Poland
Download PDF Download RIS Download Bibtex

Abstract

The article analyzes trends in steam coal flows (exports and imports) linked to production and consumption volumes. The analysis carried out in the article took the years from 2000 to 2019 into consideration. Coal is the second most important energy carrier. Its share in the structure of global consumption amounts to 27% and its production has an upward trend despite its decreasing share. The overall global upward trend of steam coal flows was disrupted twice over the period 2000–2019: by the effects of the 2007–2009 global financial crisis and the ongoing uncertainty of the global economy, as well as by the significant slowdown in the economic growth of developing countries (2014–2016). The European Union has seen large decreases in coal consumption over recent years, reflecting an accelerating decarbonization policy. The main area of coal trade is the Asia-Pacific basin. The Atlantic market currently accounts for about 20% of global steam coal trade, with seaborne trade covering about 95%. The volume of world trade (exports, imports) in steam coal is approximately one billion (bn) tons per year. The analysis carried out showed the following trend: decreasing coal exports to economically developed countries (mainly concentrated in Europe) and increasing exports to economies of developing countries, concentrated in the Asian part of the world. International Energy Agency (IE A) projections show that by 2040 the global coal production will fall from 5.6bn tons of coal equivalent (3.9bn tons of oil equivalent in 2019) to 5bn tce (3.5bn toe) at an average annual rate of –1.1%. Steam coal production is expected to decline by 10% to 4bn tce (2.8bn toe). Due to the fact that China is the largest producer, user and importer of steam coal in the world, all economic and political decisions taken by its government have strongly influenced international coal trade for years. For the Asia-Pacific basin alone, the IE A’s long-term forecasts predict an increase in coal-fired power generation over 2019. Forecasts regarding the coal’s share in global demand are not optimistic for many regions of the world (Europe, Africa, the Americas), predicting a significant decline in its demand. Yet, new markets for coal are emerging, especially in Asia and the Mediterranean basin, which may contribute to maintaining at least the current level of coal trade.
Go to article

Authors and Affiliations

Katarzyna Stala-Szlugaj
1
ORCID: ORCID
Zbigniew Grudziński
1
ORCID: ORCID

  1. Mineral and Energy Economy Research Institute of the Polish Academy of Sciences, Kraków, Poland
Download PDF Download RIS Download Bibtex

Abstract

The paper presents formulas which can be used to determine steam condensation pressure in a power plant condenser in off-design conditions. The mathematical model provided in the paper makes it possible to calculate the performance of the condenser in terms of condensing steam pressure, cooling water temperature at the condenser outlet, and condenser effectiveness under variable load conditions as a function of three input properties: the temperature and the mass flow rate of cooling water at the condenser inlet and the mass flow rate of steam. The mathematical model takes into account values of properties occurring in reference conditions but it contains no constant coefficients which would have to be established based on data from technical specifications of a condenser or measurement data. Since there are no such constant coefficients, the model of the steam condenser proposed in the paper is universally applicable. The proposed equations were checked against warranty measurements made in the condenser and measurement data gathered during the operation of a 200 MW steam power unit. Based on the analysis, a conclusion may be drawn that the proposed means of determining pressure in a condenser in off-design conditions reflects the condenser performance with sufficient accuracy. This model can be used in optimization and diagnostic analyses of the performance of a power generation unit.
Go to article

Bibliography

[1] Salij A., Stepien J.C.: Performance of Turbine Condensers in Power Units of Thermal Systems. Kaprint, Warsaw 2013 (in Polish).
[2] Rusowicz A.: Issues Concerning Mathematical Modelling of Power Condensers. Warsaw University of Technology, Warsaw 2013 (in Polish).
[3] Grzebielec A., Rusowicz A.: Thermal resistance of steam condensation in horizontal tube bundles. J. Power Technol. 91(2011), 1, 41–48.
[4] Laskowski R., Smyk A., Rusowicz A., Grzebielec A.: Selection of cooling water mass flow rate at variable load for 200 MW power unit. Rynek Energii (2020), 3,41– 46 (in Polish).
[5] Durmayaz A., Sogut O. S.: In?uence of cooling water temperature on the e?ciency of a pressurized-water reactor nuclear-power plant. Int. J. Energ. Res. 30(2006), 10, 799–810.
[6] Atria S.I.: The influence of condenser cooling water temperature on the thermal efficiency of a nuclear power plant. Ann. Nucl. Energy 80(2015), 371–378.
[7] Lakovic M.S., et.al. Stojiljkovic M.M. , Lakovic S.V., Stefanovic V.P., Mitrovic D.D.: Impact of the cold end operating conditions on energy efficiency of the steam power plants. Therm. Sci. 14(2010), Suppl., S53–S66.
[8] Laskowski R., Smyk A., Lewandowski J., Rusowicz A.: Cooperation of a steam condenser with a low-pressure part of a steam turbine in off-design conditions. Am. J. Energ. Res. 3(2015), 1, 13–18.
[9] Cengel Y.A.: Heat Transfer. McGraw-Hill, 1998.
[10] Holman J.P.: Heat Transfer. McGraw-Hill, New York 2002.
[11] Weber G.E., Worek W.M.: Development of a method to evaluate the design performance of a feedwater heater with a short drain cooler. J. Eng. Gas Turbines Power 116(1994), 2, 434–441.
[12] Weber G.E., Worek W.M.: The application of a method to evaluate the design performance of a feedwater heater with a short drain cooler. J. Eng. Gas Turbines Power 117(1995), 2, 384–387.
[13] Szkłowier G.G., Milman O.O.: Research and Calculations of Condensing Systems of Steam Turbines. Energoatomizdat, Moskwa 1985 (in Russian).
[14] Pattanayak L., Padhi B.N., Kodamasingh B.: Thermal performance assessment of steam surface condenser. Case Stud. Therm. Eng. 14(2019), 100484.
[15] Beckman G., Heil G.: Mathematische Modelle für die Beurteilung von Kraftwerksprozessen. EKM Mitteillungen (1965), 10.
[16] Laskowski R., Lewandowski J.: Simplified and approximated relations of heat transfer effectiveness for a steam condenser. J. Power Technol. 92(2012), 4, 258– 265.
[17] Laskowski R.M.: A mathematical model of the steam condenser in the changed conditions. J. Power Technol. 92(2012), 2, 101–108.
[18] Szapajko G., Rusinowski H.: Empirical modelling of heat exchangers in a CHP plant with bleed-condensing turbine. Arch. Thermodyn. 29(2008), 4, 177–184.
[19] Szapajko G., Rusinowski H.: Mathematical modelling of steam–water cycle with auxiliary empirical functions application. Arch. Thermodyn. 31(2010), 2, 165–183.
[20] Bahadori A.: Simple method for estimation of effectiveness in one tube pass and one shell pass counter-flow heat exchangers. Appl. Energ. 88(2011), 11, 4191–4196.
[21] Vera-García F., García-Cascales J.R., Gonzálvez-Maciá J., Cabello R., Llopis R., Sanchez D., Torrella E.: A simplified model for shell-and-tubes heat exchangers: practical application. Appl. Therm. Eng. 30(2010), 10, 1231–1241.
[22] Patrascioiu C., Radulescu S.: Modeling and simulation of the double tube heat exchanger. Case studies. Advances in Fluid Mechanics & Heat & Mass Transfer (P. Mastny, V. Perminov, Eds.). In: Proc. 10th WSEAS Int. Conf. on Heat Transfer, Thermal Engineering and Environment (HTE ’12) and Proc. 10th WSEAS Int. Conf. on Fluid Mechanics & Aerodynamics (FMA ’12), Istanbul, Aug. 21–23, 2012, WSEAS, 2012, 35–41.
[23] Patrascioiu C., Radulescu S.: Prediction of the outlet temperatures in triple concentric-tube heat exchangers in laminar flow regime: case study. Heat Mass Transfer 51(2015), 59–66.
[24] Laskowski R.: The black box model of a double-tube counter-flow heat exchanger. Heat Mass Transfer (2014), 10.1007/s00231-014-1482-2.
[25] Chmielniak T., Trela M., Eds.: Diagnostics of New-Generation Thermal Power Plants. Wyd. IMP PAN, Gdansk 2008.
[26] Butrymowicz D., Trela M.: Influence of fouling and inert gases on the performance of regenerative feedwater heaters. Arch. Thermodyn. 23(2002), 1-2, 127–140.
[27] Badur J., Kowalczyk T., Ziółkowski P., Tokarczyk P., Wozniak M.: Study of the effectiveness of the turbine condenser air extraction system using hydro ejectors. Trans. Inst. Fluid-Flow Mach. 131(2016), 41–53.
[28] Tokarczyk P.,Woznizk M., Badur J., Kowalczyk T., Ziółkowski P.: Issue of the temperature of water supplied to hydro ejector and its influence on performance of steam turbine condenser. Energetyka 70(2017), 10 (in Polish).
[29] HEI Standards for Steam Surface Condensers (11th Edn.). Heat Exchange Institute, Cleveland 2012.
[30] Prieto M.M., Suárez I.M., Montanés E.: Analysis of the thermal performance of a church window steam condenser for different operational conditions using three models. Appl. Therm. Eng. 23(2003), 2, 163–178.
[31] Wróblewski W., Dykas S., Rulik S.: Selection of the cooling system configuration for an ultra-critical coal-fired power plant. Energ. Convers. Manage. 76(2013), 554– 560.
[32] Jian-qun Xu, Tao Yang, You-yuan Sun, Ke-yi Zhou, Yong-feng Shi: Research on varying condition characteristic of feedwater heater considering liquid level. Appl. Therm. Eng., 67 (2014), 179–189.
[33] Laskowski R.: Relations for steam power plant condenser performance in off-design conditions in the function of inlet parameters and those relevant in reference conditions. Appl. Therm. Eng. 104(2016), 528–536.
[34] Laskowski R., Smyk A., Rusowicz A., Grzebielec A.: A useful formulas to describe the performance of a steam condenser in off-design conditions. Energy 204(2020) 117910.
[35] Wagner W., Kretzschmar H.J.: International Steam Tables – Properties of Water and Steam based on the Industrial Formulation IAPWS-IF97. Springer, 2008.
Go to article

Authors and Affiliations

Rafał Laskowski
1
Adam Smyk
1
Adam Ruciński
1
Jacek Szymczyk
1

  1. Institute of Heat Engineering, Faculty of Power and Aeronautical Engineering, Warsaw University of Technology, Nowowiejska 21/25, 00-665 Warsaw, Poland
Download PDF Download RIS Download Bibtex

Abstract

The paper presents the results of the numerical analyses for the steam turbine rotor, dedicated for the newly-designed 900 MW steam unit with supercritical steam parameters (650 °C, 30.0 MPa). Basing on the design calculations, an optimal design solution was determined. Review of the available literature on materials for turbine rotors with supercritical steam parameters was done. Then the start-ups of the turbine were simulated. Thermal and strength states were analyzed. As a result, an optimal start-up characteristic was obtained.

Go to article

Authors and Affiliations

Henryk Łukowicz
Andrzej Rusin
Marian Lipka
Download PDF Download RIS Download Bibtex

Abstract

The article presents an analysis of Russia’s participation in international steam coal trade, which has been its important participant for years. The research covered the years 2014–2018. The geographical location on two continents and the availability of coal deposits, favors its presence on both the Pacific and Atlantic markets. The article also discusses the main coal producers in Russia and the prices of Russian steam coal directed to the spot market. Due to the significant share of coal exports for the Russian economy, the focus was also on analyzing Russian seaports.

In recent years, Asian exports have dominated in Russian steam coal exports. The share of export to this market in the years 2014–2018 was in the range of 49–57% (60–87 million tons). Currently, three countries play an important role among Asian countries: South Korea, China and J apan. They purchased a total of 38–52 million tons of Russian coal. Although in the years under analysis Russia exported 52–67 million tons of steam coal to the European market, the share of this market dropped from almost half to around 40%. T he slow departure from coal energy contributes to reducing the share of recipients from this direction. Among European countries, in 2014 the main direction of export was Great Britain with 19% (24 million tons) of total export share. In 2018, exports fell to 9 million tons (5%).

Among European destinations for Russian coal, Poland’s share is growing in importance. In the years 2014–2018, steam coal exports to Poland varied in the range of 5.6–16.2 million tons. In the years 2014–2018 it changed in the range of 5.6–16.2 million tons. The dynamic growth achieved in the last three years is noteworthy. In relation to 2016, imports increased by 10.0 million tons and in 2018 amounted to as much as 16.1 million tons. The article also discusses the geographical structure of coal imports to Poland by railway border crossings and seaports.

Go to article

Authors and Affiliations

Katarzyna Stala-Szlugaj
Zbigniew Grudziński
Download PDF Download RIS Download Bibtex

Abstract

In Poland, there is a growing awareness of the need to change the sources of electricity and heat. An expression of this is the adoption of the document entitled Poland’s Energy Policy until 2040 (PEP 2040) in February 2020 by the Council of Ministers. The goal of the Polish Energy Policy until 2040 is “energy security – ensuring the competitiveness of the economy, energy efficiency and reducing the environmental impact of the energy sector – taking into account the optimal use of own energy resources”. In PEP 2040, the previous assumptions of the state’s long-term energy policy were amended and an increase in the use of low- or non-emission sources was declared. In addition, the energy policy guidelines contain forecasts for the production of steam coal and the demand for this raw material. Based on the provisions of the document, as well as forecasts of the coal-production volume prepared by the authors and the assessments of experts in the fields related to energy and mining, the article contains considerations on the validity of the developed forecasts together with the determination of the production capacity of domestic mining enterprises in terms of covering the demand for steam coal used for the production of electricity and heat. It is planned, inter alia, that blocks of coal-fired power plants will be decommissioned and, in their place, there is to be the expansion of solar and wind energy and the commissioning of the first blocks of a nuclear power plant. Such activities, which cause a decrease in the demand for coal, are also related to the plans of changes in the functioning of mining enterprises – there will be successive closures of individual mines and mining plants.
Go to article

Authors and Affiliations

Marian Czesław Turek
1
Patrycja Bąk
2
ORCID: ORCID

  1. Central Mining Institute, Katowice, Poland
  2. AGH University of Science and Technology, Kraków, Poland
Download PDF Download RIS Download Bibtex

Abstract

Steam discharge produces noise due to rapid expansion and a temperature drop of ejected steam. This is why steam silencers are used to change one-stage into multi-stage expansion, which reduces the intensity of pressure and temperature drop during this process and shifts emitted noise into higher frequencies, which are easier to dampen. This paper presents a flow-acoustic numerical model of a steam silencer. It is meant to help to obtain a precise analysis of phenomena occurring in steam silencers and improve the process of designing this type of device. The model described in this paper was based on the parameters of a real working unit manufactured in the Institute of Power Engineering – Thermal Technology Branch. Most of the steam silencers are designed based on construction guidelines that have not been changed for a long time. This restrained an increase in the acoustics efficiency of the steam silencers. An improvement of their flow and acoustic properties allows for the development of smaller, more efficient, and lighter construction. The current version of the model was used for the analysis of flow and acoustic changes which occur after modifying the lower region of a shell of the steam silencer. The proposed modification allowed for a 19% increase in mass flow rate through the silencer and noise reduction in the low-frequency range.
Go to article

Bibliography

[1] Karczewski J., Kopania J., Bogusławski G.: Reduction of noise from industrial installations, i.e. steam blow-off silencers. Energetyka Cieplna i Zawodowa 712(2018), 14–19 (in Polish).
[2] Vincent P., Larsonnier F., Rodrigues D., Durand S.: Analytical modeling and characterization of an infrasound generator in the air. Appl. Acoust. 148(2019), 476–483.
[3] Nowicki G., Nowicki T.J., Prystup A., Slusarska B., Chemperek E.: Effects of infrasound generated in urban areas on health of people and animals – an attempt to localize environmental infrasound sources using computer simulations. J. Pre-Clin. Clin. Res. 8(2014), 2, 81–85.
[4] Sorokin L.I.: Calculation and Measurements of the Characteristics of Noise Created in a Far Noise Field by Jet Planes. Mashinostroenie, Moscow 1968 (in Russian).
[5] Klyuevl V.V.: Handbook on the Control of Industrial Noises. Mashinostroenie, Moscow 1979 (in Russian).
[6] Dragun D.K., Perfil’ev Yu.P., Liukevich N.V., Khotulev V.A.: Shaft-Type Launchers. Bauman MGTU, Moscow 2003 .
[7] Lukashchuk V.N.: Noise generated during operations for purging steam superheaters and development of measures to reduce its influence on the environment. PhD thesis, Moscow 1988.
[8] Hockle M., Muller H.A.: A Handbook on Technical Acoustics. Sudostroenie, Leningrad 1980 (in Russian).
[9] Kurlze G.: Physik und Technik der Lermbergdampfung. G. Brann Buchverlag, Karlsruhe 1963 (in German).
[10] Middelberg J.M., Barber T.J., Leong S.S., Byrne K.P., Leonardi E.: Computational fluid dynamics analysis of the acoustic performance of various simple expansion chamber mufflers. In: Proc. Acoustics 2004, Gold Coast, 3-5 Now. 2004.
[11] Hu X., Zhou Y., Fang J., Man X., Zhao Z.: Computational fluid dynamics research on pressure loss of cross-flow perforated muffler. Chin. J. Mech. Eng. 20(2007), 2, 88–93 (English Edn.).
[12] Tupov V.B., Taratorin A.A.: The choice of turbulence models for steam jet. Procedia Engineer. Dynamic and Vibroacoustics of Machines (DVM2016) 176(2017), 199–206.
[13] Taratorin A.A., Tupov V.B.: Detection techniques of acoustical centre of noise source, Therm. Eng. 62(2015), 7, 480–483.
[14] Journal of Laws of the Republic of Poland (Dziennik Ustaw Rzeczypospolitej Polskiej), Item 2288, Attachment 7, 21/11/2019.
[15] Mohanty A.R, Pattnaik S.P.: An Optimal Design Methodology for a Family of Perforated Mufflers. SAE Tech. Pap. 2005-26-053, 2005.
[16] Zheng S., Kamg Z.X., Lian X.M.: Acoustic Matching Simulation of Muffler with Hybrid Approach. SAE Tech. Pap. 2011-01-1516, 2011.
[17] Comsol Multiphysics 5.6 Release Highlights. https://www.comsol.com/release/5.6 (acessed 24 March 2021).

Go to article

Authors and Affiliations

Patryk Gaj
1
Krzysztof Sobczak
2
Joanna Kopania
3
Kamil Wójciak
1

  1. Institute of Power Engineering, Mory 8, 01-330 Warsaw, Poland
  2. Lodz University of Technology, Wólczanska 219, 90-924 Lodz, Poland
  3. Lodz University of Technology, Piotrkowska 266, 90-924 Lodz, Poland
Download PDF Download RIS Download Bibtex

Abstract

Approximately 95% of international trade in steam coal is concentrated in two areas: Asia-Pacific and Atlantic. Prices on the international market depend on the largest exporters and users of coal. The aim of the article is to characterize the price trends that took place in the international trade of energy coal in the years 2000–2020 and to distinguish price indices which, in the opinion of the authors, currently play an important role in this trade. The analysis of steam coal prices in international markets in 2000–2020 made it possible to highlight five periods of rising prices, four periods of falling prices, and one period of the stabilisation of prices. A detailed analysis of the highlighted periods of steam coal price fluctuations in 2000–2020 made it possible to identify groups of factors that significantly affect the level of prices of the analyzed coal in the long term. International steam coal markets are interlinked despite periodic volatility. A very important factor influencing world steam coal prices is the situation in China as it is the largest producer, user and importer of steam coal. A small change in coal production in China significantly affects the volume of trade on the international market. Therefore, the level of freight prices is an important factor influencing the price level for the customer. FOB Australia prices are also correlated with coal suppliers to the European market and Asia-Pacific market in this paper. The very high correlation coefficients obtained confirm the close relationship between the prices of these coals. For many years, the European market has no longer been a trendsetter in international coal markets but has instead been affected by general trends.
Go to article

Authors and Affiliations

Katarzyna Stala-Szlugaj
1
ORCID: ORCID
Zbigniew Grudziński
1
ORCID: ORCID

  1. Mineral and Energy Economy Research Institute of the Polish Academy of Sciences, Kraków, Poland
Download PDF Download RIS Download Bibtex

Abstract

The aim of this article is to provide an overview of other alternative directions of coal supply to Poland following the February 2022 embargo on coal imports from Russia. Due to the dominant role of steam coal in imports to Poland, the authors focused on this type of coal. Analysis of the share of Russian steam coal imported into Poland in domestic consumption and production suggests that this commodity has played a relatively important role in the Polish market. In 2010–2021, between 4.8 and 12.9 million tonnes were imported annually from Russia to Poland, accounting for 8–25% of domestic steam-coal consumption. In 2018–2021, steam coal imported into Poland accounted for 22–29% of the volume of coal shipped by Russia to all EU -27 countries. In order to fill the gap left by Russian coal, this article considers alternative routes of coal supply to Poland, namely from Australia, Indonesia, Colombia, South Africa and the US, and presents the qualitative characteristics of the coal offered by these alternative routes of coal supply and traded on the international market. Between 2010 and 2021, steam-coal-price offers from these countries followed a consistent trend, with the difference between the minimum and maximum offer ranging from USD 5–32/tonne. As the steam coal supply of each of the analyzed routes of supply is fraught with some risk, the authors have also identified in the article those directions that may present some difficulties. It was found that coal offerings from Australia, South Africa, Indonesia and Colombia have low sulphur content (less than 1%), while coals from Australia and South Africa have relatively high ash content (from 12% to nearly 25%). Towards the end, the article also addresses issues related to the transport of coal to Poland and its dispatching within the country. As the analyzed alternative directions of coal imports involve importing this commodity by sea, the authors also analyzed the reloading capacity of Polish seaports and the rail transport fleet.
Go to article

Authors and Affiliations

Katarzyna Stala-Szlugaj
1
ORCID: ORCID
Zbigniew Grudziński
1
ORCID: ORCID

  1. Mineral and Energy Economy Research Institute, Polish Academy of Sciences, Kraków, Poland
Download PDF Download RIS Download Bibtex

Abstract

Superheater is for generating superheated steam from the saturated steam from the evaporator outlet. In the case of pulverized coal fired boiler, a relatively small amount of ash causes problems with ash fouling on the heating surfaces, including the superheaters. In the convection pass of the boiler, the flue gas temperature is lower and ash deposits can be loose or sintered. Ash fouling not only reduces heat transfer from the flue gas to the steam, but also is the cause of a higher pressure drop on the flue gas flow path. In the case the pressure drop is greater than the power consumed by the fan increases. If the superheater surfaces are covered with ash than the steam temperature at the outlet of the superheater stages falls, and the flow rates of the water injected into attemperator should be reduced. There is also an increase in flue gas temperature after the different stages of the superheater. Consequently, this leads to a reduction in boiler efficiency. The paper presents the results of computational fluid dynamics simulations of the first stage superheater of both the boiler OP-210M using the commercial software. The temperature distributions of the steam and flue gas along the way they flow together with temperature of the tube walls and temperature of the ash deposits will be determined. The calculated steam temperature is compared with measurement results. Knowledge of these temperatures is of great practical importance because it allows to choose the grade of steel for a given superheater stage. Using the developed model of the superheater to determine its degree of ash fouling in the on-line mode one can control the activation frequency of steam sootblowers.
Go to article

Authors and Affiliations

Marcin Trojan
Download PDF Download RIS Download Bibtex

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.

Go to article

Authors and Affiliations

Piotr Duda
Dariusz Rząsa
Download PDF Download RIS Download Bibtex

Abstract

This article describes the validation of a supercritical steam cycle. The cycle model was created with the commercial program GateCycle and validated using in-house code of the Institute of Power Engineering and Turbomachinery. The Institute's in-house code has been used extensively for industrial power plants calculations with good results. In the first step of the validation process, assumptions were made about the live steam temperature and pressure, net power, characteristic quantities for high- and low-pressure regenerative heat exchangers and pressure losses in heat exchangers. These assumptions were then used to develop a steam cycle model in Gate-Cycle and a model based on the code developed in-house at the Institute of Power Engineering and Turbomachinery. Properties, such as thermodynamic parameters at characteristic points of the steam cycle, net power values and efficiencies, heat provided to the steam cycle and heat taken from the steam cycle, were compared. The last step of the analysis was calculation of relative errors of compared values. The method used for relative error calculations is presented in the paper. The assigned relative errors are very slight, generally not exceeding 0.1%. Based on our analysis, it can be concluded that using the GateCycle software for calculations of supercritical power plants is possible.
Go to article

Authors and Affiliations

Janusz Kotowicz
Henryk Łukowicz
Łukasz Bartela
Sebastian Michalski
Download PDF Download RIS Download Bibtex

Abstract

Temperature related decrease of steam turbine components is one of the main transient processes that occur during a typical long-term operation. With a natural cooling (no user interference) it takes more than 14 days before the temperature of components reaches the level that allows to open and repair a turbine. It is then reasonable to apply a forced cooling in order to decrease the time between a shut-down of a power generating unit and a beginning of a repair. This paper presents the analysis of application of a forced cooling process to supercritical steam turbines. The main problems under the investigation are the safety issues of the process and the optimization of cooling conditions. The paper describes the safety restrictions and the optimization criteria. The process is analyzed in numerical simulations conducted for various cooling conditions.
Go to article

Authors and Affiliations

Wojciech Kosman
Download PDF Download RIS Download Bibtex

Abstract

The paper presents a description of selected models dedicated to steam condensing flow modelling. The models are implemented into an in-house computational fluid dynamics code that has been successfully applied to wet steam flow calculation for many years now. All models use the same condensation model that has been validated against the majority of available experimental data. The state equations for vapour and liquid water, the physical model as well as the numerical techniques of solution to flow governing equations have been presented. For the single-fluid model, the Reynolds-averaged Navier-Stokes equations for vapour/liquid mixture are solved, whereas the two-fluid model solves separate flow governing equations for the compressible, viscous and turbulent vapour phase and for the compressible and inviscid liquid phase. All described models have been compared with relation to the flow through the Laval nozzle.
Go to article

Authors and Affiliations

Włodzimierz Wróblewski
Tadeusz Chmielniak
Sławomir Dykas
Download PDF Download RIS Download Bibtex

Abstract

The study presented here offers an analysis of the heat flow through the wall of the Yankee cylinder when regarded as a thin-walled vessel. The effect of the selected design and process parameters (i.e. cylinder diameter and steam pressure) on density of the heating stream has been analyzed and discussed for both cast iron and steel cylinders. Based on the work presented here, the optimal ranges for steam pressure have been derived and proposed for cylinders mounted at various locations within the drying section.

Go to article

Authors and Affiliations

Włodzimierz Kawka
Mariusz Reczulski
Download PDF Download RIS Download Bibtex

Abstract

The paper presents a new method of lifetime calculations of steam turbine components operating at high temperatures. Component life is assessed on the basis of creep-fatigue damage calculated using long-term operating data covering the whole operating period instead of representative events only. The data are analysed automatically by a dedicated computer program developed to handle big amount of process data. Lifetime calculations are based on temperature and stress analyses performed by means of finite element method and using automatically generated input files with thermal and mechanical boundary conditions. The advanced lifetime assessment method is illustrated by an example of lifetime calculations of a steam turbine rotor.

Go to article

Authors and Affiliations

Mariusz Banaszkiewicz
Wojciech Radulski
Krzysztof Dominiczak
Download PDF Download RIS Download Bibtex

Abstract

The paper presents a thermal-economic analysis of different variants of a hard coal-fired 900 MW ultra-supercritical power unit. The aim of the study was to determine the effect of the parameters of live and reheated steam on the basic thermodynamic and economic indices of the thermal cycle. The subject of the study was the cycle configuration proposed as the "initial thermal cycle structure" during the completion of the project "Advanced Technologies for Energy Generation" with the live and reheated steam parameters of 650/670 °C. At the same time, a new concept of a thermal cycle for ultra-supercritical parameters with live and reheated steam temperature of 700/720 °C was suggested. The analysis of the ultra-supercritical unit concerned a variant with a single and double steam reheat. All solutions presented in the paper were subject to a detailed thermodynamic analysis, as well as an economic one which also included CO2emissions charges. The conducted economic analysis made it possible to determine the maximum value of investment expenditures at which given solutions are profitable.
Go to article

Authors and Affiliations

Sebastian Rulik
Henryk Łukowicz
Sławomir Dykas
Katarzyna Stępczyńska
Download PDF Download RIS Download Bibtex

Abstract

The article presents current state of the structure of hard coal enrichment plants in Poland, taking the capacity, the range of grain enrichment and the type of equipment used into account. This data were presented in a tabular format for each Polish Coal Company operating on the Polish market. The article was also present simplified: flow sheet of the steam and coking coal enrichment system. Based on the presented data, the planned needs and trends were described in terms of increasing production efficiency, minimizing water consumption and safety of work. A list of research and development works which must be undertaken were also presented as well as factors determining the technological development of the processing plants.

Go to article

Authors and Affiliations

Ireneusz Baic
Wiesław Blaschke
Bronisław Gaj
Download PDF Download RIS Download Bibtex

Abstract

The paper presents selected issues related to the development of international coal markets. World consumption of coal dropped for the second year in a row in 2016, primarily due to lower demand from China and the U S. The share of coal in global primary energy consumption decreased to 28%. World coal production accounted to 3.66 billion toe and it was lower by 6.2% when compared to the previous year. More than 60% of this decline took place in China. The decline in global production was more than four times higher than the decrease in consumption. The sufficiency of world resources of coal are estimated at 153 years – that is three times more than the sufficiency of oil and gas resources. After several years of decline, coal prices increased by 77% in 2016. The current spot prices are at the level of $80/t and are close to the 2014 prices. In the European market, after the first half of the year, coal prices reached the level of around 66% higher than in the same period of the last year. The average price in the first half amounted to PLN 12.6/GJ, which is close to the 2012 prices. The share of spot trade in the total purchase amount accounted to approx. 20%. Prices in futures contracts can be estimated on the basis of the Japan-Australia contracts prices and prices in supplies to power plants located in Germany. On average, the prices in supplies to these power plants were higher by approximately 9% in the years 2010–2016 and prices in Australia – Japan contracts were 12% higher than CIF ARA prices in 2017. Global energy coal trade reached about 1.012 billion tonnes in 2016. In 2019, a decline by 4.8% is expected primarily due to the expected reduction in the demand in major importing countries in Asia.

Go to article

Authors and Affiliations

Zbigniew Grudziński

This page uses 'cookies'. Learn more