scholarly journals Thermo-economic analysis of an efficient lignite-fired power system integrated with flue gas fan mill pre-drying

2018 ◽  
Author(s):  
Junjie Yan ◽  
Xiaoqu Han ◽  
Jiahuan Wang ◽  
Ming Liu ◽  
Sotirios Karellas
Keyword(s):  
Moisture Content ◽  
Economic Analysis ◽  
Power System ◽  
Energy Saving ◽  
Flue Gas ◽  
Power Plants ◽  
Waste Heat ◽  
Low Rank ◽  
Analysis Model ◽  
Energy Saving Potential

Lignite is a domestic strategic reserve of low rank coals in many countries for its abundant resource and competitive price. Combustion for power generation is still an important approach to its utilization. However, the high moisture content always results in low efficiencies of lignite-direct-fired power plants. Lignite pre-drying is thus proposed as an effective method to improve the energy efficiency. The present work focuses on the flue gas pre-dried lignite-fired power system (FPLPS), which is integrated with fan mill pulverizing system and waste heat recovery. The thermo-economic analysis model was developed to predict its energy saving potential at design conditions. The pre-drying upgrade factor was defined to express the coupling of pre-drying system with boiler system and the efficiency improvement effect. The energy saving potential of the FPLPS, when applied in a 600 MW supercritical power unit, was determined to be 1.48 %-pts. It was concluded that the improvement of boiler efficiency mainly resulted from the lowered boiler exhaust temperature after firing pre-dried low moisture content lignite and the lowered dryer exhaust gas temperature after pre-heating the boiler air supply. Keywords: lignite; pre-drying; thermodynamic analysis; thermo-economics

scholarly journals Thermal and Economic Analysis of Multi-Effect Concentration System by Utilizing Waste Heat of Flue Gas for Magnesium Desulfurization Wastewater

Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5384 ◽  
Author(s):  
Mingwei Yan ◽  
Yuetao Shi
Keyword(s):  
Wastewater Treatment ◽  
Power Plant ◽  
Economic Analysis ◽  
Magnesium Sulfate ◽  
Flue Gas ◽  
Power Plants ◽  
Waste Heat ◽  
Optimization System ◽  
Benchmark System ◽  
Better Than

Compared with limestone-based wet flue gas desulfurization (WFGD), magnesia-based WFGD has many advantages, but it is not popular in China, due to the lack of good wastewater treatment schemes. This paper proposes the wastewater treatment scheme of selling magnesium sulfate concentrate, and makes thermal and economic analysis for different concentration systems in the scheme. Comparisons of different concentration systems for 300 MW power plant were made to determine which system is the best. The results show that the parallel-feed benchmark system is better than the forward-feed benchmark system, and the parallel-feed optimization system with the 7-process is better than other parallel-feed optimization systems. Analyses of the parallel-feed optimization system with 7-process were made in 300, 600, and 1000 MW power plants. The results show that the annual profit of concentration system for a 300, 600, and 1000 MW power plant is about 2.58 million, 5.35 million, and 7.89 million Chinese Yuan (CNY), respectively. In different concentration systems of the scheme for selling magnesium sulfate concentrate, the parallel-feed optimization system with the 7-process has the best performance. The scheme can make a good profit in 300, 600, and 1000 MW power plants, and it is very helpful for promoting magnesia-based WFGD in China.

scholarly journals An Improved System for Utilizing Low-temperature Waste Heat of Flue Gas from Coal-Fired Power Plants

2017 ◽  
Author(s):  
Shengwei Huang ◽  
Chengzhou Li ◽  
Tianyu Tan ◽  
Peng Fu ◽  
Gang Xu ◽  
...  
Keyword(s):  
Low Temperature ◽  
Energy Saving ◽  
Flue Gas ◽  
Power Output ◽  
Power Plants ◽  
Waste Heat ◽  
Low Pressure ◽  
Steam Extraction ◽  
Pressure Steam ◽  
Net Power Output

In this paper, an improved system to efficiently utilize the low-temperature waste heat (WHUS) from the flue gas of coal-fired power plants is proposed based on heat cascade. The essence of the proposed system is that the waste heat of exhausted flue gas is not only used to preheat air for assisting coal combustion as usual but also to heat up feedwater and the low-pressure steam extraction. Preheated by both the exhaust flue gas in the boiler island and the low-pressure steam extraction in the turbine island, thereby part of the flue gas heat in the air preheater can be saved and introduced to heat the feedwater and the high-temperature condensed water. Consequently, part of the high-pressure steam is saved for further expansion in the steam turbine, which obtains additional net power output. Based on the design data of a typical 1000 MW ultra-supercritical coal-fired power plant in China, in-depth analysis of the energy-saving characteristics of the optimized WHUS and the conventional WHUS is conducted. When the optimized WHUS is adopted in a typical 1000 MW unit, net power output increases by 19.51 MW, exergy efficiency improves to 45.46%, and net annual revenue reaches 4.741 million USD. In terms of the conventional WHUS, these aforementioned performance parameters are only 5.83 MW, 44.80% and 1.244 million USD, respectively. The research of this paper can provide a feasible energy-saving option for coal-fired power plants.

Economic Analysis of Wet Flue Gas Desulfurization System with the Application of Low Pressure Economizer for Waste Heat Recovery

2015 ◽  
Vol 1092-1093 ◽  
pp. 491-497 ◽  
Author(s):  
Jing Hui Song ◽  
Yan Lin ◽  
Yan Fen Liao ◽  
Xiao Qian Ma ◽  
Shu Mei Wu
Keyword(s):  
Economic Analysis ◽  
Power Consumption ◽  
Water Consumption ◽  
Flue Gas ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Power Plants ◽  
Waste Heat ◽  
Low Pressure ◽  
Flue Gas Desulfurization

The data of wet flue gas desulfurization (WFGD) power and water consumption, from two different coal-fired power plants (100 MW and 1000 MW) under full load operation, are studied for the WFGD economic analysis of waste-heat-recovery transformation with the installation of low pressure economizer (LPE). The results of 100MW unit show that, WFGD inlet flue gas temperature drops from 155°C to 110°C, the benefits generated include power consumption of fans declines by 23.85% and water consumption of the smoke desulfurization absorption tower declines by 34.88%. In another case, the temperature of inlet flue gas from WFGD of 1000 MW unit drops from 130°C to 84°C, power consumption of fans increases by 15.04% while water consumption of the smoke desulfurization absorption tower declines by 73.1%. Besides, the flow resistance is increased in LPE water side due to the installation of LPE. This makes power consumption of condensate pump enhanced, which slightly decreases the benefits from waste heat recovery.

scholarly journals Economic Analysis of Waste Heat Utilization for Coal-fired Power Units

2018 ◽  
Vol 57 ◽  
pp. 02004
Author(s):  
Wang Kai ◽  
Lu Kun ◽  
Wang Shuai
Keyword(s):  
Economic Analysis ◽  
Power Plants ◽  
Waste Heat ◽  
Economic Effect ◽  
Load Condition ◽  
Analysis Model ◽  
Coal Consumption ◽  
Heat Utilization ◽  
Waste Heat Utilization ◽  
Saving Effect

Strict energy conservation policies require power plants to minimize energy consumption as much as possible. Low pressure economizer is an effective method to recycle waste heat from boiler exhaust gas. In this paper, the economic analysis model of coal-fired power plant is established by means of equivalent enthalpy drop method, and the waste heat utilization effect on thermal systems is investigated, including boiler efficiency, steam turbine power output, condensate pump, induced draft fan, electro static precipitator and desulfurization system. Then the economic effect on a 1000 MW ultra super critical unit in Shandong Province is calculated. The results show that waste heat utilization could comprehensively reduce standard coal consumption rate by 1.89 g/(kW·h), and the unit could save about 10.8 thousand tons standard coal and 1.29 billion dollars every year. Besides, the energy saving effect is more significant for lower load condition.

A novel lignite pre-drying system integrated with flue gas waste heat recovery at lignite-fired power plants

2019 ◽  
Vol 150 ◽  
pp. 200-209 ◽  
Author(s):  
Min Yan ◽  
Chunyuan Ma ◽  
Qiuwan Shen ◽  
Zhanlong Song ◽  
Jingcai Chang
Keyword(s):  
Flue Gas ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Power Plants ◽  
Waste Heat ◽  
Drying System

The Energy-Saving Diagnosis of PWR Nuclear Power Station Based on the Thermo-Economic Analysis Model

2010 ◽  
Author(s):  
Juan Chen ◽  
Tao Zhou ◽  
Ke Ran
Keyword(s):  
Graph Theory ◽  
Economic Analysis ◽  
Energy Saving ◽  
Nuclear Power Station ◽  
Nuclear Power ◽  
Exergy Analysis ◽  
Performance Estimation ◽  
Structure Theory ◽  
Analysis Model ◽  
Power Station

Exergy analysis model of PWR nuclear power station is developed in which signal flowing graph theory is introduced to set up the relation equations between input exergy flow and output exergy flow. Then, combining with resource distribution between different components, thermo-economic analysis model is obtained by setting up unit thermo-economic cost equations of different components with productive structure graph. Taking Daya Bay as an example, exergy analysis and thermal-economic analysis are put forward with detailed distribution of exergy and investment cost. Finally, aimed at energy-saving, static diagnosis is performed in two levels: energy conservation and cost reduction, and on this basis dynamic diagnosis is developed through sensitivity analysis considering different influence factors such as main steam temperature, fuel price, construction capital investment, post treatment cost and so on. The introduction of signal flow graph theory and thermal-economic structure theory is helpful to do performance estimation with high speed and good accuracy. It provides a new way for rapid optimization and offers an effective theoretical method for energy-saving of PWR nuclear power station including advanced reactor such as AP1000.

Thermo-economic analysis and optimization of combined PERC - ORC - LNG power system for diesel engine waste heat recovery

2018 ◽  
Vol 173 ◽  
pp. 613-625 ◽  
Author(s):  
Hamed Habibi ◽  
Mohammad Zoghi ◽  
Ata Chitsaz ◽  
Koroush Javaherdeh ◽  
Mojtaba Ayazpour
Keyword(s):  
Diesel Engine ◽  
Economic Analysis ◽  
Power System ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat

Flue Gas Denitrification Programming Model for Coal-Fired Generating Units Based on Total Emission Control Policies of NOx in China

2013 ◽  
Vol 448-453 ◽  
pp. 651-656 ◽  
Author(s):  
Yu Li ◽  
Chao Ci Li ◽  
Jing Ya Wen
Keyword(s):  
Power System ◽  
Flue Gas ◽  
Emission Reduction ◽  
Power Plants ◽  
Programming Model ◽  
Emission Control ◽  
Power Industry ◽  
Total Emission ◽  
Generation Expansion ◽  
Flue Gas Denitrification

Because of the large-scale emission of nitrous oxides (NOx) in recent years, acid rain is still one of the major air pollution problems in China, although SO2 has been well controlled. And then, the goals for the total emission control of NOx begin to move forward in the 12th five-year plan, which requires a 10% cut in national NOx emissions by 2015, relative to the 2010 level, and NOx emission reduction of coal-fired power plants are still put in a strategic position. Accordingly, it’s of great significance to carry out flue gas denitrification work around the power industry with purposes and plans. In this study, a mixed 0-1 integer nonlinear flue gas denitrification programming model for power system is developed for the first time, which can be used for planning the initial time put into operation of SCR facilities in a region and optimize the allocation of NOx emission reduction balance, which is significant for generation expansion planning. The model is applied to the power system in Heilongjiang province and the results indicate that the proposed model not only can meet the requirement of flue gas denitrification management, but also can help the coal-fired power plants clear the economic impact of NOx emission reduction on self-development. This study can provide reference for the decision support of NOx emission reduction and generation expansion in power industry.

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