Analysis Of Coal-fired Power Plant Research Articles

Performance analysis of coal-fired power plants integrated with carbon capture system under load-cycling operation conditions

Performance analysis of coal-fired power plants integrated with carbon capture system under load-cycling operation conditions

Influence of environmental parameters on the cold-end and thermal system of coal-fired power plant based on Ebsilon simulation

To analyze the influence of environmental parameters on cold-end systems, especially the natural draft wet cooling tower (NDWCT), and the thermal system, the 660 MW power plant was taken as the research subject. Based on Ebsilon, this paper researched numerically the cooling performance of NDWCT and thermal system under different environmental conditions. The simulation results showed that increasing dry bulb temperature and environmental humidity causes a decline of water temperature drop (△t), which deteriorates the cooling performance and leads to adverse effects on the thermal system. As dry bulb temperature rises from 20℃ to 30℃, total power generation and system efficiency drop by 6484.89 kW and 0.18 %, respectively, and drop by 9912.72 kW and 0.86 % when environmental humidity elevates from 35 % to 75 %. Meanwhile, simulation investigations demonstrated that crosswind affects seriously NDWCT and further affects the thermal system. When crosswind speed increases from 0.21 m/s to 4.75 m/s, △t and system efficiency drop by 1.6℃ and 0.17 %, respectively, and gross coal consumption rate rises by 1.14 g/(kW∙h), which leads to the reduction of thermal system economy. In all, influence of environmental parameters on cold-end system, especially NDWCT, and the entire thermal system were revealed, which provided a basis for dynamic analysis of coal-fired power plants.

Thermodynamic analysis of coal-fired power plant based on the feedwater heater drainage-air preheating system

As coal-fired power plants are the main source of coal consumption, their energy generation efficiency needs to be improved urgently. One of the main reasons for irreversible energy loss in coal-fired power plants is the mismatched energy levels. To reduce the irreversible energy loss and improve the generation efficiency, the thermodynamic system of the coal-fired power plant needs to be optimized. In this work, a mathematical model of thermodynamic system has been established based on balance principles of mass and energy, which has been validated by design values of a 600 MW coal-fired power plant. Meanwhile, a novel air preheating system based on the feedwater heater drainage has been proposed, to utilize energy from the steam turbine extraction and boiler flue gas. Compared with the conventional schemes, the power supply efficiency of this optimized scheme improved by 1.7%, the coal consumption reduced by 13.1 g/kWh, and the generation cost reduced by 1.85 $/MWh. This work provides an accurate mathematical model for the thermodynamic system of a thermal power plant and an effective optimization method for improving the generation efficiency of a coal-fired power plant.

Exergy Analysis of Coal-Fired Power Plants in Ultra Supercritical Technology versus Integrated Gasification Combined Cycle

Exergy Analysis of Coal-Fired Power Plants in Ultra Supercritical Technology versus Integrated Gasification Combined Cycle

Rate-based simulation and techno-economic analysis of coal-fired power plants with aqueous ammonia carbon capture

Ammonia is a promising solvent for the chemical absorption of carbon dioxide owing to its characteristics of low toxicity, low degradation, low cost, and low heat of desorption. The present work evaluates the energy and economic performances of the aqueous ammonia technology applied to a coal-fired power plant. First, the kinetics of absorption are characterized in the Aspen Plus software and are calibrated against the experimental data from the Munmorah pilot plant. Then, the validated model is used for sizing the full-scale plant columns and for simulating the overall capture plant. After determining the sizes of the plant components and their energy consumptions, the capture plant is integrated with the coal-fired power plant, and the economic analysis is assessed with both retrofitted and green-field approaches as described in reports from the European Benchmarking Task Force and the United States National Energy Technology Laboratory, respectively. The novelties presented here are the new approach in the absorption reactions implemented in the rate-based model, which changes the dependency of the ammonia concentration in the absorption process, as well as the full economic analysis with both retrofitted and green-field assumptions, which enable a sound comparison of the outcomes. The results with the retrofitted approach compared with the monoethanolamine case of the European Benchmarking Task Force report returned higher electric efficiency (36.3% versus 33.50%), lower levelized cost of electricity (87.66 €/MWhel versus 92.27 €/MWhel), and lower cost of carbon dioxide avoided (47.03 €/tonCO2 versus 51.62 €/tonCO2). The results using the green-field approach compared against the Cansolv case of the National Energy Technology Laboratory report returned higher electric efficiency (33.06% versus 32.50%), lower cost of electricity (124.3 $/MWhel versus 133.2 $/MWhel) and lower cost of carbon dioxide avoided (66.5 $/tonCO2 versus 75.25 $/tonCO2). In both comparisons, aqueous ammonia had appreciably better performance than the ammine reference cases.

Economic Analysis of Power Plants Under Different Loads Based on Structural Theory

The economy analysis of coal-fired power plants is usually based on traditional thermal balance method, which only considers the thermodynamic factors but ignores the economic factors such as cost. In this paper, to have a more comprehensive and accurate evaluation on the production performance and economical efficiency of thermal systems, the cost analysis method based on the Structural Theory of Thermoeconomic is applied to a 300MW thermal power generating unit in Yunnan province. The thermoeconomic model and the exergetic cost model for the plant based on the Fuel—Product concept have been defined to quantify the productive interaction between different devices. By calculating the thermoeconomic cost of four typical different working conditions and analyzing the distributions and change rules of generating cost, the Structural Theory of Thermoeconomic is proved scientific and useful and offers a set of feasible and reliable analysis method for the performance analyses and improvement of power plants.

Thermodynamic and economic investigation of coal-fired power plant combined with various supercritical CO2 Brayton power cycle

The supercritical CO2 Brayton power cycle is well known as a promising power generation technology, and researches for applying it to various applications are being actively carried out. In this study, performance analysis of coal-fired power plant combined with supercritical CO2 Brayton power cycle was performed. If various existing supercritical CO2 Brayton power generation cycles are applied to coal-fired power generation systems, the expected power generation efficiency and levelized cost of electricity (LCOE) are thoroughly estimated. In conclusion, it is expected that the power generation efficiency is improved by 6.2–7.4% compared to the steam Rankine cycle applied to the existing coal-fired power plant, and the LCOE of the coal-fired power plant combined with the supercritical CO2 Brayton cycle is reduced by about 7.8–13.6% compared to that of coal-fired power plant combined with steam Rankine cycle. In addition, design criteria for retaining the economic dominance were presented through sensitivity analysis of factors affecting O&M cost and capital cost.

Thermodynamic and ecological assessment of selected coal-fired power plants integrated with carbon dioxide capture

The primary objective of the study presented in this paper was a thermodynamic and ecological analysis of coal-fired power plants integrated with carbon dioxide capture installations working in different technologies (pre-combustion, oxy-combustion and post-combustion) and a comparison of these systems with reference systems, i.e. ones not-integrated with CO2 capture. Calculations were performed using our own developed mathematical models for the integrated units. The article quantitatively demonstrates that the integration of a carbon dioxide capture installation with a power plant causes a significant decrease in the net power and efficiency in relation to the reference system (without capture). In the case of a conventional coal unit working in the post-combustion technology and integrated with an absorption CO2 capture installation and compression of carbon dioxide to 15MPa, the net efficiency decreases in relation to the reference plant by 11.75 percentage points. The oxy-combustion unit was characterized by a decrease in efficiency (in relation to the power plant operating in the air combustion technology not integrated with Carbon Capture and Storage (CCS) installation) equal to 7.85 percentage points. In the unit working in pre-combustion technology (Integrated Gasification Combined Cycle (IGCC) system) integrated with a membrane CO2 separation installation the efficiency decrease relative to the unit without capture was equal to 16.89 percentage points.The main advantage of those systems integrated with carbon dioxide capture installations is the significant reduction of emissions to the atmosphere (environmental effect). This effect significantly depends on the separation method and the obtained effect of separation. Implementation of the capture plant in the analyzed post-combustion system allowed for a reduction of the value of the average annual CO2 emission rate aggravating unit of net electricity produced from nearly 735kgCO2/MWh to 100.77kgCO2/MWh. In the case of the unit working in IGCC technology integrated with membrane CO2 capture, this rate was equal to 89kgCO2/MWh. The lowest value was obtained for the power plant working in oxy-combustion technology, for which the emission rate was obtained at 19kgCO2/MWh.

No.22 中国山西省における石炭火力発電脱硫の外部性評価

No.22 中国山西省における石炭火力発電脱硫の外部性評価

Burden of Disease from Rising Coal-Fired Power Plant Emissions in Southeast Asia.

Southeast Asia has a very high population density and is on a fast track to economic development, with most of the growth in electricity demand currently projected to be met by coal. From a detailed analysis of coal-fired power plants presently planned or under construction in Southeast Asia, we project in a business-as-usual scenario that emissions from coal in the region will triple to 2.6 Tg a-1 SO2 and 2.6 Tg a-1 NOx by 2030, with the largest increases occurring in Indonesia and Vietnam. Simulations with the GEOS-Chem chemical transport model show large resulting increases in surface air pollution, up to 11 μg m-3 for annual mean fine particulate matter (PM2.5) in northern Vietnam and up to 15 ppb for seasonal maximum 1 h ozone in Indonesia. We estimate 19 880 (11 400-28 400) excess deaths per year from Southeast Asian coal emissions at present, increasing to 69 660 (40 080-126 710) by 2030. 9000 of these excess deaths in 2030 are in China. As Chinese emissions from coal decline in coming decades, transboundary pollution influence from rising coal emissions in Southeast Asia may become an increasing issue.

DEA cross-efficiency evaluation considering undesirable output and ranking priority: a case study of eco-efficiency analysis of coal-fired power plants

Data envelopment analysis cross-efficiency evaluation has been widely accepted as a useful tool for performance evaluation and ranking of decision making units. However, the non-uniqueness of optimal weights is a problem that has reduced the usefulness of this powerful method. In addition, current studies generally have not considered the situation in which undesirable outputs appear in the data envelopment analysis cross-efficiency evaluation. To solve these problems, firstly, we present an equitable model for efficiency evaluation of decision-making units with undesirable outputs and introduce a technique for cross-efficiency evaluation considering undesirable outputs. Then, a ranking priority model is proposed considering the decision making units' intentions of pursuing the best ranking positions. In addition, an aggressive model is given to guarantee the uniqueness of the optimal solution. The proposed approach can not only solve the problem of non-uniqueness of optimal weights in data envelopment analysis cross-efficiency evaluation but also considers undesirable outputs and ranking preferences of the decision-making units. Finally, the proposed approach is applied for eco-efficiency analysis of coal-fired power plants in a big data environment, and the results show that most coal-fired power plants in China have not performed well.

Exergy Analysis of Coal-Fired Power Plants in Two Cooling Condition

The distribution of exergy destruction is different in power plant systems with water cooled condenser and air cooled condenser. A detailed comparison based on a conventional Rankine cycle with two different cooling configurations is carried out in this paper in an exergy perspective. The inefficiency of the overall systems is analyzed in the same amount of heat transfer capacity condition, it shows that the distribution of exergy destruction among components is similar in both conditions. And this study of energy consumption is benefit for realization of auto-efficient-working power plants in future.

Construction of Energy Conservation and Emission Reduction Evaluation Index System in Coal-Fired Power Plants and its Application

According to the analysis of coal-fired power plants, the article built the evaluation index system of coal-fired power plants energy conservation and emission reduction. Based on analytic hierarchy process (AHP), we determined the weight of each evaluation index. By using the calculation of rating scores in cleaner production, we set up a model of energy conservation and emission reduction for coal-fired power plants. On the basis of the results, the level of coal-fired power plants energy conservation and emission reduction was divided into five levels: excellent, good, medium, pass and fail. Taking a coal-power plant in Heilongjiang Province as an example, we drew a conclusion that the score of energy conservation and emission reduction in the coal-power plant was 89.52 which represents the good level. According to the evaluation result, we proposed corresponding suggestions. The results provide decision-makers with ideas and methods for energy conservation and emission reduction evaluation in the coal-fired power plant.

Lifecycle Analysis of Coal-fired Power Plants with CCS in China

Abstract Carbon capture and storage (CCS) is a potential CO 2 emission mitigation technology for coal-fired power plants. In order to assess the mitigation effect, we carried out a comprehensive evaluation of coal-fired power plants with CCS by using the lifecycle analysis (LCA). Total 6 routes of coal-fired power plants with CCS were defined and studied in the paper. The results show that the CO 2 emission of power generation dominates the total lifecycle CO 2 emission; the indirect CO 2 emission induced by coal mining and washing also accounts for a large part of lifecycle emission; CO 2 emission of EOR is much larger than that of aquifer storage, which reduces the CO 2 emission mitigation of CCS.

Energy Consumption Analysis of Coal-Fired Power Plant with CO<sub>2</sub> Capture System Based on Solar Energy

To the question of high energy consumption and cost about coal-fired power plant CO2emission,this paper from the coupling mechanism research of solar energy collection system,amidogen CO2emission reduction system and coal-fired power plant thermal system ,as well as systematic integration and optimization ,and then based on equivalent heat drop method ,It analyses the thermal economy changes about this new type integration system at THA, 75% THA, 50% THA conditions corresponding to the different carbon capture rate of the four programs .Finally,it works out the unit thermal economy variation tendency at different rate of carbon capture,its thermal economy relative degree increase if capture rate increase .On this basis ,this paper optimizes the integration system in order to achieve low power consumption, low cost of CO2 emissions for reference.

국내 초임계 석탄화력발전소에 연소 후 CO2포집공정 설치 시 성능 및 경제성 평가

국내 초임계 석탄화력발전소에 연소 후 <TEX>$CO_2$</TEX> 포집공정을 설치하였을 경우에 예상되는 발전단가와 <TEX>$CO_2$</TEX> 저감비용(Cost of <TEX>$CO_2$</TEX> avoided)을 산출하였다. 본 연구에서 고려된 연소 후 <TEX>$CO_2$</TEX> 포집기술은 이미 상업적으로 적용이 가능하고, 기존의 화력발전에 적용이 용이한 아민 화합물을 이용한 화학 흡수법을 기초로 하였으며, 경제성 평가를 위해 연간 발생하는 비용 및 발전량을 연간 균등화(Levelized)하여 발전단가를 산정하는 수명기간 중 발전단가 분석(LCCA: Life Cycle Cost Analysis) 방식을 활용하여 분석하였다. 경제성 평가에서 가장 중요한 항목 중 하나인 설비 투자비(건설비 등) 및 운영비 산출을 위해, 기존의 <TEX>$CO_2$</TEX> 포집 설비가 없는 기준 석탄화력발전소의 건설비는 IEA(국제에너지기구)에서 제시하는 국내 초임계석탄화력 발전소(순출력 767 MW급)의 데이터를 활용하였으며, 석탄화력발전소에 <TEX>$CO_2$</TEX> 포집설비가 추가된 경우에도 IEA에서 제시하는 기준 석탄화력발전소와 <TEX>$CO_2$</TEX> 포집설비 설치 후의 OECD 평균 순공사비(Overnight cost) 증감분을 참조하여 계산하였다. 상기 데이터를 이용하여 기존 석탄화력발전소 및 <TEX>$CO_2$</TEX> 포집 설비 설치 후의 발전단가 및 <TEX>$CO_2$</TEX> 포집비용을 분석한 결과 <TEX>$CO_2$</TEX> 포집설비 설치 후 발전 효율은 기존 초임계 석탄화력발전소의 발전효율 41%에서 31.6%로 약 9.4%가 저하되었으며, 발전단가는 기존의 45.5 USD/MWh에서 73.9 USD/MWh로 약 62%가 증가되었고 <TEX>$CO_2$</TEX> 포집비용은 41.3 USD/<TEX>$tCO_2$</TEX>로 산출되었다. In this study, Economic analysis of supercritical coal-fired power plant with <TEX>$CO_2$</TEX> capture process was performed. For this purpose, chemical absorption method using amine solvent, which is commercially available and most suitable for existing thermal power plant, was studied. For the evaluation of the economic analysis of coal-fired power plant with post-combustion <TEX>$CO_2$</TEX> capture process in Korea, energy penalty after <TEX>$CO_2$</TEX> capture was calculated using the power equivalent factor suggested by Bolland et al. And the overnight cost of power plant (or cost of plant construction) and the operation cost reported by the IEA (International Energy Agency) were used. Based on chemical absorption method using a amine solvent and 3.31 GJ/<TEX>$tonCO_2$</TEX> as a regeneration energy in the stripper, the net power efficiency was reduced from 41.0% (without <TEX>$CO_2$</TEX> capture) to 31.6% (with <TEX>$CO_2$</TEX> capture) and the levelized cost of electricity was increased from 45.5 USD/MWh (Reference case, without <TEX>$CO_2$</TEX> capture) to 73.9 USD/MWh (With <TEX>$CO_2$</TEX> capture) and the cost of <TEX>$CO_2$</TEX> avoided was estimated as 41.3 USD/<TEX>$tonCO_2$</TEX>.