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.

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

Entropy ◽  
2017 ◽  
Vol 19 (8) ◽  
pp. 423 ◽  
Author(s):  
◽  
◽  
◽  
◽  
◽  
...  
Keyword(s):  
Low Temperature ◽  
Flue Gas ◽  
Power Plants ◽  
Waste Heat

Application of Double-Used Absorption Heat Pump in Power Plants

2012 ◽  
Vol 542-543 ◽  
pp. 70-73 ◽  
Author(s):  
Xin Hui Cao ◽  
Guang Zhang ◽  
Xi Lun Wang ◽  
Yu Ning Zhang
Keyword(s):  
Power Plant ◽  
Energy Saving ◽  
Heat Pump ◽  
Power Plants ◽  
Waste Heat ◽  
Water Saving ◽  
Energy Utilization ◽  
Absorption Heat Pump ◽  
Quantitative Calculation ◽  
Steam Extraction

Absorption heat pump (AHP) heating in power plants in winter is an effective way to recover waste heat and make full use of energy. In this paper, quantitative calculation is taken to analyze the energy saving and economy efficiency of AHP heating in a power plant. The rate of energy utilization ηtp, the coal and water saving amount and the increased income of AHP heating are calculated. Results show AHP heating in power plants is superior to steam extraction heating both in energy saving and economy.

scholarly journals Modification and Application of Low and Low Temperature Economizer in Dezhou Power Plant

2021 ◽  
Vol 271 ◽  
pp. 01022
Author(s):  
Qiudong Hu
Keyword(s):  
Power Plant ◽  
Low Temperature ◽  
Flue Gas ◽  
Power Plants ◽  
Waste Heat ◽  
National Policy ◽  
Dust Removal ◽  
Gas Temperature ◽  
Coal Consumption ◽  
Waste Heat Recovery System

At present, the exhaust gas temperature of coal-fired power plants is 125-150℃, and the emission of high-temperature flue gas causes the loss of excess heat and wastes. For this kind of phenomenon, the waste heat recovery system is researched and designed, combined with the combination of a low-temperature economizer in a coal-fired power plant in Dezhou. The heater, through the low-temperature economizer combined with the heater system, reduces coal consumption for power generation, reduces flue gas emissions, while reducing dust specific resistance, improving dust removal efficiency of electric dust removal, and reducing dust emissions. This project responds to national policy guidelines.

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 Thermodynamic Optimization of a Waste Heat Power System under Economic Constraint

Energies ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3388
Author(s):  
Liya Ren ◽  
Jianyu Liu ◽  
Huaixin Wang
Keyword(s):  
Heat Source ◽  
Power System ◽  
Economic Performance ◽  
Power Output ◽  
Power Plants ◽  
Performance Indicator ◽  
Waste Heat ◽  
Electricity Production ◽  
Heat Power ◽  
Net Power Output

A novel thermo-economic performance indicator for a waste heat power system, namely, MPC, is proposed in this study, which denotes the maximum net power output with the constraint of EPC ≤ EPC0, where EPC is the electricity production cost of the system and EPC0 refers to the EPC of conventional fossil fuel power plants. The organic and steam Rankine cycle (ORC, SRC) systems driven by the flue gas are optimized to maximize the net power output with the constraint of EPC ≤ EPC0 by using the Non-dominated Sorting Genetic Algorithm-II (NSGA-II). The optimization process entails the design of the heat exchangers, the instantaneous calculation of the turbine efficiency, and the system cost estimation based on the Aspen Process Economic Analyzer. Six organic fluids, n-butane, R245fa, n-pentane, cyclo-pentane, MM (Hexamethyldisiloxane), and toluene, are considered for the ORC system. Results indicate that the MPC of the ORC system using cyclo-pentane is 39.7% higher than that of the SRC system under the waste heat source from a cement plant with an initial temperature of 360 °C and mass flow rate of 42.15 kg/s. The precondition of the application of the waste heat power system is EPC ≤ EPC0, and the minimum heat source temperatures to satisfy this condition for ORC and SRC systems are obtained. Finally, the selection map of ORC versus SRC based on their thermo-economic performance in terms of the heat source conditions is provided.

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

Pilot test of environment-friendly catalysts for the DeNOx of low-temperature flue gas from a coal-fired plant

2021 ◽  
Author(s):  
Lin Guo ◽  
Jianjiang Lu ◽  
Yonggang Zhao ◽  
Chengzhi Wang ◽  
Cheng Zhang ◽  
...  
Keyword(s):  
Low Temperature ◽  
Energy Saving ◽  
Flue Gas ◽  
Small Scale ◽  
Pilot Test ◽  
Environment Friendly ◽  
Efficient Environment

Efficient, environment-friendly, and energy-saving low-temperature denitration (DeNOx) catalysts, applicable in practical flue gas, has a widespread market for use in small-scale boilers. A novel Ce-based low-temperature honeycomb catalyst was tested...

In situ optical monitoring of AlAs wet oxidation using a novel low-temperature low-pressure steam furnace design

1998 ◽  
Vol 10 (2) ◽  
pp. 197-199 ◽  
Author(s):  
S.A. Feld ◽  
J.P. Loehr ◽  
R.E. Sherriff ◽  
J. Wiemeri ◽  
R. Kaspi
Keyword(s):  
Low Temperature ◽  
Low Pressure ◽  
Wet Oxidation ◽  
Optical Monitoring ◽  
Furnace Design ◽  
Pressure Steam

Waste Heat Recovery in a Cruise Vessel in the Baltic Sea by Using an Organic Rankine Cycle: A Case Study

2015 ◽  
Author(s):  
Fredrik Ahlgren ◽  
Maria E. Mondejar ◽  
Magnus Genrup ◽  
Marcus Thern
Keyword(s):  
Power Output ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Operating Conditions ◽  
Maritime Transportation ◽  
Working Fluid ◽  
Net Power Output

Maritime transportation is a significant contributor to SOx, NOx and particle matter emissions, even though it has a quite low CO2 impact. New regulations are being enforced in special areas that limit the amount of emissions from the ships. This fact, together with the high fuel prices, is driving the marine industry towards the improvement of the energy efficiency of current ship engines and the reduction of their energy demand. Although more sophisticated and complex engine designs can improve significantly the efficiency of the energy systems in ships, waste heat recovery arises as the most influent technique for the reduction of the energy consumption. In this sense, it is estimated that around 50% of the total energy from the fuel consumed in a ship is wasted and rejected in fluid and exhaust gas streams. The primary heat sources for waste heat recovery are the engine exhaust and the engine coolant. In this work, we present a study on the integration of an organic Rankine cycle (ORC) in an existing ship, for the recovery of the main and auxiliary engines exhaust heat. Experimental data from the operating conditions of the engines on the M/S Birka Stockholm cruise ship were logged during a port-to-port cruise from Stockholm to Mariehamn over a period of time close to one month. The ship has four main engines Wärtsilä 5850 kW for propulsion, and four auxiliary engines 2760 kW used for electrical consumers. A number of six load conditions were identified depending on the vessel speed. The speed range from 12–14 knots was considered as the design condition, as it was present during more than 34% of the time. In this study, the average values of the engines exhaust temperatures and mass flow rates, for each load case, were used as inputs for a model of an ORC. The main parameters of the ORC, including working fluid and turbine configuration, were optimized based on the criteria of maximum net power output and compactness of the installation components. Results from the study showed that an ORC with internal regeneration using benzene would yield the greatest average net power output over the operating time. For this situation, the power production of the ORC would represent about 22% of the total electricity consumption on board. These data confirmed the ORC as a feasible and promising technology for the reduction of fuel consumption and CO2 emissions of existing ships.

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