scholarly journals Fuel consumption of thermal power technologies under maneuvering modes

2020 ◽  
Vol 2020 (4) ◽  
pp. 45-49
Author(s):  
V.S. Kobernik ◽  

A characteristic feature of the present day development of power engineering lies in the increase in the unevenness of power systems schedules. The structure of generating powers of Ukrainian energy engineering is overloaded with basic powers and characterized by a sharp deficit of maneuvering wanes. To cover the uneven load of the power system during the operation of existing and construction of new power plants, it is necessary to take into account the possibility of their operation under maneuvering modes. This paper determines the influence of work of power plants i under maneuvering modes on the specific consumption of conditional fuel on the released electric energy at working on gas or coal fuel. Fuel consumption for starting of a unit depends on its type and downtime in reserve. The use of steam–and–gas facilities and gas turbines helps to enhance the maneuverability of power plants. Alternative options for the development of thermal energy are the introduction of gas–piston power plants and power units with fluidized–bed boilers. We present formulas for the calculations of fuel consumption on by power units for start–ups and specific consumptions depending on the load and degree of their involvement to regulating loads for different thermal energy technologies: steam–turbine condensation and district heating power units; steam–and–gas and gas turbine plants; gas piston installations; power units with fluidized bed boilers. For enhancing the maneuverability of power plants, working on fossil fuels, their modernization and renewal of software are necessary. Quantitative assessment of the efficiency of power units and separate power plants during their operation under variable modes is important for forecasting the structure of generating capacities of power systems, the need to introduce peak and semi–peak capacities, the choice of the most profitable composition of operating equipment at different schedules of electrical loads Keywords: thermal power, power unit, maneuverable mode, electrical load, specific fuel consumption

2022 ◽  
Vol 25 (6) ◽  
pp. 762-772
Author(s):  
E. L. Stepanova ◽  
A. P. Ovchinnikov

The present work examines average relative capital investment and fuel consumption for electric and thermal energy supply of the combined-cycle plants having 30–125 MW gas turbines commissioned at Russian thermal power plants in 2015–2020. In this work, we used general calculation methods of average relative capital investments and fuel consumption for the electrical and thermal energy supply using power equipment of thermal power plants. To assess the scope of commissioning gas turbines incorporated into the combined-cycle plants, they were classified into three groups by electrical power: 30–59 MW, 60–99 MW and 100–125 MW. The scope of commissioning gas turbines incorporated into the Russian combined-cycle plants in 2015–2020 was analysed. The average relative capital invest-ment in combined-cycle plants having 30–125 MW gas turbines, as well as the average specific fuel consumption for the electrical and thermal energy supply, were calculated. The calculations were carried out for each part of combined-cycle plants integrated into thermal power plants with a breakdown by seven Unified Energy Systems of Russia. The quantita-tive commissioning of gas turbines is compared for the periods from 2010 to the economic crisis of 2014 and after 2014 to the present: a ~2.5-fold decrease is demonstrated. A preliminary evaluation of the increase in average relative capital investment in combined-cycle plants having gas turbines of the same electric power was performed.


2004 ◽  
Vol 126 (3) ◽  
pp. 921-928 ◽  
Author(s):  
Amnon Einav

This paper reviews the pioneering efforts done in Israel over the last 50 years to explore different directions of developing the solar energy resource as an alternative energy supply. An early start included the improvement of solar collectors for heating water for domestic uses. This was followed by low-temperature Organic Rankine Cycle turbines to supply electricity for remote locations, and then the development and commercialization of the SEGS Solar Thermal power plants. Current research directions are described, including high temperature Solar Tower power systems, production of “solar fuels” at high temperature to enable storage and transportation of solar energy, photovoltaic materials and photovoltaic systems development, solar absorption cooling, and the bold idea of large “Energy Towers” to produce electric energy from cooling of hot dry desert air. The paper concludes that additional efforts in Israel and abroad to continue developing and deploying of solar energy systems, having benevolent influence on the environment, should continue.


Author(s):  
Ainur A. Kuandykova ◽  
Vitaly M. Lebedev

The existing issues during the combustion of Kazakh coal from the Ekibastuz basin in the Omsk energy system are noted. The environmental problems of coal generation in Omsk are outlined. The possibility of transferring the Omsk coal-fired thermal power plants to the combustion of domestic coals is considered. The options for increasing the efficiency of using solid fossil fuel in the production of electric and thermal energy are given. The existing problem of storing ash and slag wastes obtained by burning high-ash Ekibastuz coals is noted. The transfer of the Omsk CHPPs to the combustion of brown coal from the Kansk-Achinsky deposit, provided that highly effective environmentally friendly technologies are used It is noted that the technology of combustion of fuels in a circulating fluidized bed (CFB) has been industrially developed and implemented in power boilers. The results of operation of the first in Russia CFB boiler of unit No. 9 with a capacity of 330 MW at the Novocherkasskaya SDPP are presented


2021 ◽  
Vol 1045 ◽  
pp. 212-225
Author(s):  
Olena Svietkina ◽  
Kostiantyn Bas ◽  
Sergiy Boruk ◽  
Roman Klishchenko ◽  
Oleksandr Yehurnov ◽  
...  

In Ukraine, up to 75% of all electricity is supplied by thermal power plants, the main type of fuel for which is coal, which leads to the release of ash and slag waste at power plants in huge quantities. Every 10 years (according to statistical data) the amount of ash and slag produced at thermal power plants doubles. The use and creation of new modified consumers of coal-water fuel (CWF) and coal-water suspensions (CWS) occurs periodically. The ease of handling suspensions is captivating: in the energy sector, they can serve as the basis for the effective disposal of numerous accumulated wastes from coal preparation and oil refining, a significant reduction in the consumption of minerals for generating heat and electric energy, and minimizing the effect of heat power engineering on public health and the state of nature.


Author(s):  
W. J. Thayer ◽  
R. T. Taussig

Applications of energy exchangers, a type of gasdynamic wave machine, were evaluated in power plants fired by pressurized, fluidized bed combustors (PFBCs). Comparative analyses of overall power plant efficiency indicate that the use of energy exchangers as hot gas expanders may provide a 0.5 to 1.5 efficiency point increase relative to gas turbines. In addition, the unique operating characteristics of these machines are expected to reduce rotating component wear by a factor of 50 to 300 relative to conventional gas turbines operating in the particulate laden PFBC effluent stream.


2019 ◽  
Vol 109 ◽  
pp. 00119
Author(s):  
Volodymyr Yemelianenko ◽  
Vitalii Pertsevyi ◽  
Oleksandr Zhevzhyk ◽  
Iryna Potapchuk ◽  
Oleksandr Lutai

Analysis of the perspectives of the coal fuel for thermal power plants is carried out. The necessity of the experimental study for temperature measurement in the boiler furnace. The results of the experimental study are presented: temperature change over time at the burner outlet for different constant pressure value of the backlighting gas, dependence of the temperature at the burner outlet from the backlighting gas pressure for constant concentration value of pulverized coal in coal-air mixture, dependence of the temperature at the burner outlet from the concentration of pulverized coal in coal-air mixture for constant value of the backlighting gas pressure, temperature measurements for constant backlighting gas pressure value, constant value of the concentration of pulverized coal in coal-air mixture when plasmatron is switched and operates for some time range. The results of the study could be applied to the solid fuel treatment for different thermal units.


Author(s):  
Christian Felsmann ◽  
Uwe Gampe ◽  
Manfred Freimark

Solar hybrid gas turbine technology has the potential to increase the efficiency of future solar thermal power plants by utilizing solar heat at a much higher temperature level than state of the art plants based on steam turbine cycles. In a previous paper the authors pointed out, that further development steps are required for example in the field of component development and in the investigation of the system dynamics to realize a mature technology for commercial application [1]. In this paper new findings on system dynamics are presented based on the simulation model of a solar hybrid gas turbine with parallel arrangement of the combustion chamber and solar receivers. The operational behavior of the system is described by means of two different scenarios. The System operation in a stand-alone electrical supply network is investigated in the first scenario. Here it is shown that fast load changes in the network lead to a higher shaft speed deviation of the electric generator compared to pure fossil fired systems. In the second scenario a generator load rejection, as a worst case, is analyzed. The results make clear that additional relief concepts like blow-off valves are necessary as the standard gas turbine protection does not meet the specific requirements of the solar hybrid operation. In general the results show, that the solar hybrid operational modes are much more challenging for the gas turbines control and safety system compared to pure fossil fired plants due to the increased volumetric storage capacity of the system.


Author(s):  
Farshid Zabihian ◽  
Alan S. Fung

Nowadays, the global climate change has been a worldwide concern and the greenhouse gases (GHG) emissions are considered as the primary cause of that. The United Nations Conference on Environment and Development (UNCED) divided countries into two groups: Annex I Parties and Non-Annex I Parties. Since Iran and all other countries in the Middle East are among Non-Annex I Parties, they are not required to submit annual GHG inventory report. However, the global climate change is a worldwide phenomenon so Middle Eastern countries should be involved and it is necessary to prepare such a report at least unofficially. In this paper the terminology and the methods to calculate GHG emissions will first be explained and then GHG emissions estimates for the Iranian power plants will be presented. Finally the results will be compared with GHG emissions from the Canadian electricity generation sector. The results for the Iranian power plants show that in 2005 greenhouse gas intensity for steam power plants, gas turbines and combined cycle power plants were 617, 773, and 462 g CO2eq/kWh, respectively with the overall intensity of 610 g CO2eq/kWh for all thermal power plants. This GHG intensity is directly depend on efficiency of power plants. Whereas, in 2004 GHG intensity for electricity generation sector in Canada for different fuels were as follows: Coal 1010, refined petroleum products 640, and natural gas 523 g CO2eq/kWh, which are comparable with same data for Iran. For average GHG intensity in the whole electricity generation sector the difference is much higher: Canada 222 vs. Iran 610g CO2eq/kWh. The reason is that in Canada a considerable portion of electricity is generated by hydro-electric and nuclear power plants in which they do not emit significant amount of GHG emissions. The average GHG intensity in electricity generation sector in Iran between 1995 and 2005 experienced 13% reduction. While in Canada at the same period of time there was 21% increase. However, the results demonstrate that still there are great potentials for GHG emissions reduction in Iran’s electricity generation sector.


Author(s):  
M.V. Cherniavskyi

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


Author(s):  
Jindrich Liska ◽  
Jan Jakl ◽  
Sven Kunkel

Abstract Turbine-generator torsional vibration is linked to electrical events in the power grid by the generator air-gap torque. Modern power systems are subject to gradual transformation by increasing flexibility demands and incorporation of renewable resources. As a result, electrical transient events are getting more frequent and thus torsional vibration is getting more and more attention. Especially in the case of large steam and gas turbines torsional vibration can cause material fatigue and present a hazard for safe machine operation. This paper freely builds on previous work, where a method for torsional vibration evaluation using an incremental encoder measurement was presented, in that it supplements error considerations to this methodology. Measurement errors such as precision of the rotor encoder manufacturing, choice of the proper sensor, its signal to noise ratio and the error of instantaneous velocity computation algorithm are analyzed. The knowledge of these errors is essential for torsional vibration as there is an indirect and relatively complicated path from the measurement to the final torsional vibration results compared to other kinds of vibration. The characteristics of particular errors of the processing chain are validated both on experimental data from a test rig as well as field data measured on turbine-generators in power plants.


Sign in / Sign up

Export Citation Format

Share Document