scholarly journals Some design characteristics of micro steam turbines for agricultural biomass energy conversion

2020 ◽  
Vol 180 ◽  
pp. 01017
Author(s):  
Gabriel-Paul Negreanu ◽  
Ion Oprea ◽  
Viorel Berbece
Keyword(s):  
Energy Content ◽  
Agricultural Waste ◽  
Appropriate Technology ◽  
Hot Water ◽  
Biomass Energy ◽  
Flow Section ◽  
Steam Turbines ◽  
Agricultural Biomass ◽  
Steam Parameters ◽  
Main Steam

The paper continues the study of reconversion of a 400 kW hot water boiler in a steam generator suitable to valorise the energy content of briquettes and pellets of agricultural biomass. After steam parameters selection (pressure, temperature, mass-flow rate), an overview of main steam machines types (axial, radial, screw, piston engine) is done. Further, a parallel design of most wide-spread ones (Laval, Curtis and radial) were performed, at different rotation speeds, in order to find the best configuration in respect with the flow section dimensions, internal efficiency and power (electrical and thermal) output. The results of the paper could be very useful for the investors in agricultural “waste-toenergy” projects in order to select appropriate technology and equipment.

Competitive Bidding by Surrogate Modeling of Steam Parameter Influence on the Attainable Start Numbers of Turbine Casings

2020 ◽  
Author(s):  
Marcel Seiler ◽  
Vitali Züch ◽  
Peter Dumstorff ◽  
Henning Almstedt
Keyword(s):  
Wall Temperature ◽  
Surrogate Model ◽  
Power Plants ◽  
Fe Model ◽  
Steam Turbines ◽  
Require Time ◽  
Steam Parameters ◽  
Fast Prediction ◽  
Main Steam ◽  
Flexible Operation

Abstract The continued expansion of fluctuating energy sources such as wind turbines and solar systems will increase the demand for more flexible operation modes of power plants. Especially steam turbines with all their components will have to sustain a higher amount of start-stop cycles in order to compensate for variations in wind and solar radiation. Besides the rotor, inner casings are an example for main steam turbine components which are strongly loaded by thermal cycles at each start and shut down procedure. A precise prediction of the attainable number of start-stop cycles enables a more flexible operation within the guaranteed lifetime. However, this would require time-consuming FE calculations for each power plant due to their specific steam parameters. In this paper, a physics based surrogate model is discussed for a fast prediction of permissible start-stop cycles at plant specific steam parameters. The correlation between the physical properties from the surrogate model (wall temperature difference and the resulting stresses) and the attainable number of start-stop cycles from the FE model is determined. A validation with a different inner casing design within a usual wall temperature range confirms the high accuracy level of the surrogate model compared to uncertainties like material scatter or casting tolerances. With the provided approach typically a higher number of starts can be efficiently calculated in the bidding phase compared to assuming only one conservative value for each turbine type or size. Furthermore, the steam parameters can be optimized for increasing the number of starts to the required value without additional and time-consuming FE calculations.

scholarly journals Research Regarding the Biomass Energy Potential of Romania

1970 ◽  
Vol 66 (2) ◽  
Author(s):  
Dana-Adriana ILUŢIU-VARVARA ◽  
Avram FIŢIU ◽  
Daniela-Elena VLADU ◽  
Aurel ŞANDOR
Keyword(s):  
Biomass Energy ◽  
Energy Potential ◽  
Agricultural Biomass

The paper presents a research regarding the biomass energy potential of Romania. Data is presented regarding the quantity and technical energy potential of the forest and agricultural biomass of Romania.

scholarly journals ANALISIS KINERJA TURBIN UAP UNIT 3 BERDASARKAN PERFORMANCE TEST DI UNIT PELAKSANA PT.PLN (PERSERO) PEMBANGKITAN ASAM-ASAM

JTAM ROTARY ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 95
Author(s):  
Kemas Ronand Mahaputra
Keyword(s):  
Performance Test ◽  
Heat Rate ◽  
Steam Pressure ◽  
Outlet Temperature ◽  
Steam Turbines ◽  
Turbine Efficiency ◽  
Rate Calculation ◽  
Temperature And Pressure ◽  
Main Steam ◽  
Unit Unit

This study purpose to determine the performance of steam turbines Unit 3 of PT.PLN (Persero) Pembangkitan Asam-asam by comparing the results of the data obtained by each performance test. This research was carried out by taking data performance tests in 2012, 2017, 2018 and 2019 and then processing the data and obtaining turbine heat rate values and average turbine efficiency then comparing the values obtained in each year. The data taken is obtained from the rendal operation of PT.PLN (Persero) Pembangkitan Asam-asam, data variables taken are load, main steam temperature inlet, main steam pressure inlet, HP heater feed outlet temperature, HP heater outlet pressure, main steam flow. Temperature and pressure obtained are then searched for enthalpy values. The data obtained to calculate the value of the turbine heat rate and turbine efficiency on average per time from each performance test then averages the value of the turbine heat rate and turbine efficiency each time the data collection performance test is then compared with the data each year.The calculation of the turbine heat rate uses the heat & mass balance method by measuring the value of the incoming and outgoing fluid differences and comparing the load obtained, the efficiency of the turbine is obtained by dividing the energy of 1 kW with a turbine heat rate then multiplying by 100%. The average turbine heat rate calculation result for each performance test which is on May 23, 2012 is 2,701, October 27, 2017 is 3,136, September 5, 2018 is 3,005, May 21, 2019 is 3,113. The average turbine efficiency value on May 23, 2012 is 37.02%, October 27 2017 is 31.39%, September 5 2018 is 33.28%, May 21, 2019 is 32.12%. The performance of PT PLN (Persero) Pembangkit Asam-asam Implementing Unit Unit 3 has decreased from 2012 to 2019 which is 4.9%

scholarly journals Investigation of Non-Isothermal Kinetics and Thermodynamic Parameters for the Pyrolysis of Different Date Palm Parts

Energies ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 6553
Author(s):  
Emmanuel Galiwango ◽  
Ali H. Al-Marzuoqi ◽  
Abbas A. Khaleel ◽  
Mahdi M. Abu-Omar
Keyword(s):  
Activation Energy ◽  
Thermodynamic Parameters ◽  
Date Palm ◽  
Energy Content ◽  
High Energy ◽  
Biomass Energy ◽  
Isothermal Kinetics ◽  
Potential Candidate ◽  
Heating Rates ◽  
Average Percentage

Using the thermalgravimetric technique, we investigated the non-isothermal combustion kinetics of abundant and low-cost date palm wastes (leaflet, rachis, fibers, and their composite) as potential biomass energy sources. The kinetic and thermodynamic parameters were determined by Flynn–Wall–Ozawa (FWO), Kissinger–Akahila–Sunose (KAS), and Starink methods. Thermogravimetric analysis results showed a major peak for the degradation of volatiles between 127–138 °C with average percentage mass loss of 68.04 ± 1.5, 65.57 ± 0.6, 62.97 ± 5.5, and 59.26 ± 3.2, for rachis, composite, leaflet, and fibers, respectively. The FWO model showed the lowest activation energy, Eα, of 157 ± 25.6, 158 ± 25.7, 164 ± 40.1, and 169 ± 51.8 kJ mol−1 for the composite, rachis, leaflet, and fibers, respectively. The positive enthalpy values confirmed an endothermic pyrolysis reaction. For all models, a minimal difference of 4.40, 5.57, 6.55, and 7.51 kJ mol−1 between activation energy and enthalpy for rachis, fibers, composite, and leaflet ensued, respectively. The KAS model was best suited to describe chemical equilibrium with average ΔG values of 90.3 ± 28.8, 99.3 ± 34.9, 178.9 ± 27.3, and 186.5 ± 38.2 kJ mol−1 for rachis, fibers, composite, and leaflet, respectively. The reaction mechanism by the Malek and Popescu methods was ((g(α)=[−ln(1−α)]14) across the conversion range of 0.1–0.9 for all heating rates. The high energy content and volatile matter combined with low energy barriers make date palm waste a potential candidate in a biorefinery.

scholarly journals Biomass Potential from Agricultural Waste for Energetic Utilization in Greece

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1095 ◽  
Author(s):  
Spyridon Alatzas ◽  
Konstantinos Moustakas ◽  
Dimitrios Malamis ◽  
Stergios Vakalis
Keyword(s):  
Agricultural Waste ◽  
Combined Heat And Power ◽  
Biomass Energy ◽  
Small Scale ◽  
Energy Potential ◽  
Annual Basis ◽  
Mediterranean Countries ◽  
Biomass Resources ◽  
Gasification Technology

The alignment of the Greek national legislation with the corresponding EU legislation has enhanced the national efforts to pursue renewable Combined Heat and Power (CHP) projects. The scope of the present study has been the identification of the available biomass resources and the assessment of their potential. In this paper, we present the results from the administrative regions of Crete, Thessaly, and Peloponnese. The levels of lignocellulosic biomass in Greece are estimated to be 2,132,286 tonnes on an annual basis, values that are very close to the cases of other Mediterranean countries like Italy and Portugal. In respect to the total agricultural residues, Crete produces 1,959,124 tonnes/year and Thessaly produces 1,759,457 tonnes/year. The most significant streams are identified to be olive pits, olive pruning, and cotton ginning remnants, with more than 100,000 tonnes/year each. In the latter part of this manuscript, a case study is presented for the development of a CHP gasification facility in Messenia. The biomass energy potential of the area is very promising, with about 3,800,000 GJ/year. The proposed small-scale gasification technology is expected to utilize 7956 tonnes of biomass per year and to produce 6630 MWh of electricity and 8580 MWh of thermal energy.

scholarly journals Elemental Composition of Biochar Obtained from Agricultural Waste for Soil Amendment and Carbon Sequestration

2019 ◽  
Vol 9 (19) ◽  
pp. 3980 ◽  
Author(s):  
Saowanee Wijitkosum ◽  
Preamsuda Jiwnok
Keyword(s):  
Surface Area ◽  
Soil Amendment ◽  
Agricultural Sector ◽  
Crop Residues ◽  
Low Cost ◽  
Agricultural Waste ◽  
Total Pore Volume ◽  
Appropriate Technology ◽  
Bet Surface Area ◽  
Agricultural Crop

For an agricultural country such as Thailand, converting agricultural waste into biochar offers a potential solution to manage massive quantities of crop residues following harvest. This research studied the structure and chemical composition of biochar obtained from cassava rhizomes, cassava stems and corncobs, produced using a patented locally-manufactured biochar kiln using low-cost appropriate technology designed to be fabricated locally by farmers. The research found that cassava stems yielded the highest number of Brunauer-Emmett-Teller (BET) surface area in the biochar product, while chemical analysis indicated that corncobs yielded the highest amount of C (81.35%). The amount of H in the corncob biochar was also the highest (2.42%). The study also showed biochar produced by slow pyrolysis was of a high quality, with stable C and low H/C ratio. Biochar’s high BET surface area and total pore volume makes it suitable for soil amendment, contributing to reduced soil density, higher soil moisture and aeration and reduced leaching of plant nutrients from the rhizosphere. Biochar also provides a conducive habitat for beneficial soil microorganisms. The findings indicate that soil incorporation of biochar produced from agricultural crop residues can enhance food security and mitigate the contribution of the agricultural sector to climate change impacts.

scholarly journals Sugarcane Industry Waste Recovery: A Case Study Using Thermochemical Conversion Technologies to Increase Sustainability

2020 ◽  
Vol 10 (18) ◽  
pp. 6481 ◽  
Author(s):  
Leonel J. R. Nunes ◽  
Liliana M. E. F. Loureiro ◽  
Letícia C. R. Sá ◽  
Hugo F. C. Silva
Keyword(s):  
Energy Content ◽  
Paper Industry ◽  
Value Added ◽  
Biomass Energy ◽  
High Mass ◽  
Thermochemical Conversion ◽  
Industry Waste ◽  
High Mass Loss ◽  
Conversion Technologies ◽  
Sugarcane Industry

The sugarcane industry has assumed an increasingly important role at a global level, with countries such as Brazil and India dominating the field. However, this causes environmental problems, since the industry produces large amounts of waste, such as sugarcane bagasse. This by-product, which is energetically partially recovered in sugar mills and in the pulp and paper industry, can make a significant contribution to the general use of biomass energy, if the usual disadvantages associated with products with low density and a high moisture content are overcome. From this perspective, thermochemical conversion technologies, especially torrefaction, are assumed to be capable of improving the fuel properties of this material, making it more appealing for potential export and use in far-off destinations. In this work, sugarcane samples were acquired, and the process of obtaining bagasse was simulated. Subsequently, the bagasse was dried and heat-treated at 200 and 300 °C to simulate the over-drying and torrefaction process. Afterward, product characterization was performed, including thermogravimetric analysis, elemental analysis, calorimetry, and energy densification. The results showed significant improvements in the energy content, from 18.17 to 33.36 MJ·kg−1 from dried bagasse to torrefied bagasse at 300 °C, showing that despite high mass loss, there is potential for a future value added chain for this waste form, since the increment in energy density could enhance its transportation and use in locations far off the production site.

Economic Analysis of a 660MW Supercritical Turbine for Steam Initial Parameters

2014 ◽  
Vol 960-961 ◽  
pp. 1550-1553 ◽  
Author(s):  
Yu Lin Tang ◽  
Shan Tu ◽  
Yang Du ◽  
Chao Wang ◽  
Hong Juan Wang
Keyword(s):  
Power Plant ◽  
Thermal Power ◽  
Steam Pressure ◽  
Heat Consumption ◽  
Operating Parameters ◽  
Steam Temperature ◽  
Operating Modes ◽  
Endothermic Process ◽  
Steam Parameters ◽  
Main Steam

Economic diagnosis of thermal power units is to determine the economy of its operating parameters and operating modes by quantitative and qualitative analysis, which is significant to economic operation and energy saving of power plant. On the basis of equivalent enthalpy drop method and the theory of variable conditions, the economic diagnosis model of operating parameters was established. As main steam temperature and main steam pressure for example, economic diagnosis of a 660MW supercritical steam turbine unit was performed. The result demonstrates that improving the main steam temperature or main steam pressure can reduce heat consumption of the unit. The essence of improving the initial steam parameters is to improve the average temperature of the steam cycle endothermic process, thus improving the circulation efficiency and reducing heat consumption. The economic impact of main steam temperature is up to 0.61g/(kW·h), while which of main steam pressure is little. Therefore, by increasing the initial steam parameters, especially the main steam temperature, to improve the economy of the entire power plant is the main way to enhance the efficiency of power plant in the current.

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