A High Efficiency Coal-Fired Power Technology With Elevated and Conventional Turbine Layout

2017 ◽  
Author(s):  
Weizhong Feng
Keyword(s):  
Environmental Protection Agency ◽  
Co2 Emission ◽  
High Efficiency ◽  
Operating Efficiency ◽  
Price Ratio ◽  
Emission Standard ◽  
Pressure Drops ◽  
The Usa ◽  
Coal Power ◽  
Reducing Co2 Emission

The bottlenecks which in developing high-efficiency Ultra Super Critical (USC) coal power technology is analyzed under the background of great pressure of reducing CO2 emission on coal power industry. The development of 700°C Advanced Ultra Super Critical (A-USC) technology has been much slower than expected mainly due to the material limitations. Double reheat systems increase the efficiency at the cost of significant increases in expense and complexity. A cross compound unit with an elevated and conventional turbine layout greatly shorten the expensive high-temperature piping, significantly cutting the piping costs as well as reduce pressure drops and heat losses which increase the efficiency and the performance-price ratio of the power unit. Engineering study demonstrates the feasibility and advantages of this design. Existing 600 °C materials and equipment manufacturing capabilities were applied to the double reheat unit with the elevated and conventional turbine-generator layout, and adding other mature energy-saving technologies which had succeed in Shanghai Waigaoqiao No.3 Power plant to achieve a net efficiency of 49.8% (6849Btu/kWh, Lower Heating Value (LHV)). Combined with a series of innovative technologies that can improve the operating efficiency and keep the efficiency from decreasing, the annual net efficiency can achieve 48.8% (LHV). This efficiency level is high enough to meet the strict CO2 emission standard (636g/kWh) issued by Environmental Protection Agency (EPA) of the USA, showing significant demonstration of reducing CO2 emission.

Cross Compound Turbine Generator Unit With Elevated and Conventional Turbine Layouts

2016 ◽  
Author(s):  
Weizhong Feng
Keyword(s):  
Power Plants ◽  
High Efficiency ◽  
Price Ratio ◽  
Turbine Generator ◽  
Pressure Drops ◽  
High Temperature Materials ◽  
Equipment Manufacturing ◽  
Engineering Study ◽  
Generator Unit ◽  
Electrical Generation

This engineering study demonstrates the feasibility and advantages of a cross compound unit with an elevated and conventional turbine layout. Existing materials and equipment manufacturing capabilities were used to design a double reheat unit using the elevated and conventional turbine layout with other mature energy-saving systems to achieve a net efficiency of 48.92%. The development of conventional coal-fired power plants is reviewed to describe the existing bottlenecks in high-efficiency Super Critical (SC) and Ultra Super Critical (USC) electrical generation units. The development of 700 °C Advanced Ultra Super Critical (A-USC) units has been much slower than expected mainly due to the material limitations. Double reheat systems increase efficiency but also significantly increase cost and complexity. This design reduces the use of expensive high-temperature materials, with significantly lower piping costs as well as lower pressure drops and heat losses which increase the efficiency and the performance-price ratio.

Detection of Radon-Progeny and Other Alpha-Emitting Radionuclides in Air Using Tensioned Metastable Fluid Detectors

2017 ◽  
Author(s):  
N. Boyle ◽  
B. Archambault ◽  
A. Hagen ◽  
C. Meert ◽  
R. P. Taleyarkhan
Keyword(s):  
Environmental Protection Agency ◽  
Temperature Effects ◽  
High Efficiency ◽  
Collection Efficiency ◽  
Nuclear Industry ◽  
Reference Laboratory ◽  
Neutron Fission ◽  
Relative Standard ◽  
Gas Seepage ◽  
The Usa

Alpha radiation emitting radon (Rn) gas seepage into homes in the USA leads to over 21,000 annual lung cancer deaths (according to the US-Environmental Protection Agency, EPA) leading to mandatory monitoring for Rn throughout the USA. In the nuclear industry alpha emitting radionuclides in air (e.g., in spent fuel reprocessing) also constitute a major safety and security-safeguards related issues. Purdue University, along with Sagamore Adams Laboratories LLC, is developing the tensioned metastable fluid detector (TMFD) technology for general-purpose alpha-neutron-fission spectroscopy. This paper focuses on rapid, high-efficiency detection of Rn and progeny in air using the novel TMFD technology; Rn and progeny isotopes in air are sparged through the TMFD detection fluid (to entrap the radioactive gas), which is then placed under a metastable state. Through tailoring the metastable fluid state, an audible and visible cavitation detection event is created and readily detected from transient bubble formation. Changing the tensioned state allows for the spectroscopic differentiability of Rn and its daughters which can be used to actively measure the equilibrium between the parent and daughter products. Such a technique can also be used to monitor the atmosphere in critical nuclear facilities for contamination from other alpha emitting isotopes (e.g., Pu, Cm, U...). TMFDs offer the unique ability for high intrinsic efficiency (>95%) alpha-neutron-fission fragment detection, while remaining blind to background beta and gamma radiation (qualified to >3.8×108 Bq m−3 using a dissolved 32P beta source, and also via gammas from a 53 R/hr 137Cs gamma source). Immunity to beta and gamma is beneficial for the discrimination of buildup of beta-emitting Thoron and Rn progeny in the detection fluid allowing for reusability. This paper will discuss the research results pertaining to detection of Radon and progeny in air, for concentrations between 74 Bq m−3 (2 pCi/L) and 740 Bq m−3 (20 pCi/L). The system measures a radon concentration between these levels to within ±15% intrinsic relative error (IRE) within 24 hours meeting the standards outlined by the American Association of Radon Scientists and Technicians-National Radon Proficiency Program (AARST-NRPP) Device Evaluation Program. Precision evaluation was also performed and the relative standard deviation defined by the AARST-NRPP was <5% exceeded the requirement of 25%. Ambient temperature effects were assessed at 10 °C and at 27 °C, which revealed a large increase in collection efficiency with decreasing sampling temperature and slight increase with increasing sampling temperature. Temperature effects on sensitivity thresholds and volumetric expansion were measured and used to compensate for variability in temperature over time. Blind testing with the help of Bowser-Morner Radon Reference Laboratory was performed and succeeded in accurately determining the Rn in air concentration to within 20% within only 6h of sampling. Finally, a 48-hour based collection time has also been developed for use in dwellings where Rn in air concentrations may vary in a day. Overall, the reproducibility and precision of TMFD technology is found to allow for an efficient, cost-effective, reliable, and environmentally friendly means of Rn and progeny detection, and by extension for use for general actinide in air monitoring for the nuclear industry.

scholarly journals Sustainable Ventilation Strategies for a Medium-Sized Space with Regional Effect

2021 ◽  
Vol 13 (9) ◽  
pp. 4651
Author(s):  
Ming-Lun Alan Fong
Keyword(s):  
Life Cycle ◽  
Life Cycle Cost ◽  
Co2 Emission ◽  
High Efficiency ◽  
Regional Climate ◽  
Cost Effective ◽  
Regional Effect ◽  
Climate Conditions ◽  
Ventilation Strategies ◽  
Set Up

The analysis of ventilation strategies is fundamentally affected by regional climate conditions and local cost databases, in terms of energy consumption, CO2 emission and cost-effective analysis. A systematic approach is covered in this paper to estimate a local economic and environmental impact on a medium-sized space located in two regions during supply-and-installation and operation phases. Three ventilation strategies, including mixing ventilation (MV), displacement ventilation (DV) and stratum ventilation (SV) were applied to medium-sized air-conditioned space with this approach. The trend of the results for three ventilation systems in the life cycle assessment (LCA) and life cycle cost (LCC) analysis is SV < DV < MV. The result of CO2 emission and regional LCC shows that SV is the lowest one in both regional studies. In comparison with the Hong Kong Special Administrative Region (HKSAR) during 20 Service years, the case analysis demonstrates that the percentage differences in LCC analysis of MV, DV & SV in Guangdong are less than 20.5%, 19.4% and 18.82% respectively. Their CO2 emission of MV, DV and SV in Guangdong are more than HKSAR in 10.69%, 11.22% and 12.05%, respectively. The present study could provide information about regional effects in the LCA and LCC analysis of three ventilation strategies emissions, and thereby help set up models for decision-making on high efficiency and cost-effective ventilation strategy plans.

Modeling of Carbon Dioxide Measurement on Cement Plants

2012 ◽  
Vol 610-613 ◽  
pp. 2120-2128 ◽  
Author(s):  
Jun Xia Peng ◽  
Liang Huang ◽  
Yu Bo Zhao ◽  
Pan Chen ◽  
Lu Zeng ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Carbon Footprint ◽  
Carbon Dioxide Emissions ◽  
Co2 Emission ◽  
Firing Process ◽  
Input Output ◽  
Carbon Dioxide Measurement ◽  
Key Steps ◽  
Furnace Slag ◽  
Reducing Co2 Emission

Input-output model on cement plants were established. Carbon dioxide emissions of key steps and carbon footprint of products were calculated and predicted using the input-output model. The results showed that CO2 emission in the plant (the production of the plant is 1320000t a year) reached 910000 t a year and CO2 emission per ton product is 0.689 ton. Over 80% of the total CO2 was emitted during the process of firing，so the firing process is the key step for reducing CO2 emission in the cement plant. Carbon footprint of three kinds of cement products including ordinary portland cement, portland pozzolan cement and portland blast furnace slag cement are 0.76, 0.59, 0.72 respectively.

scholarly journals Comparative Environmental, Economic, and Jobs Impacts in the USA of Renewable Energy Compared to Carbon Capture, Utilization, and Storage

2021 ◽  
pp. 1-7
Author(s):  
Roger H Bezdek ◽  
Keyword(s):  
Renewable Energy ◽  
Environmental Economic ◽  
Power Plant ◽  
Co2 Emissions ◽  
Carbon Capture ◽  
Power Plants ◽  
Economic Benefits ◽  
The Usa ◽  
Coal Power ◽  
And Storage

This paper assesses the relative economic and jobs benefits of retrofitting an 847 MW USA coal power plant with carbon capture, utilization, and storage (CCUS) technology compared to replacing the plant with renewable (RE) energy and battery storage. The research had two major objectives: 1) Estimate the relative environmental, economic, and jobs impacts of CCUS retrofit of the coal plant compared to its replacement by the RE scenario; 2) develop metrics that can be used to compare the jobs impacts of coal fueled power plants to those of renewable energy. The hypotheses tested are: 1) The RE option will reduce CO2 emissions more than the CCUS option. We reject this hypothesis: We found that the CCUS option will reduce CO2 emissions more than the RE option. 2) The RE option will generate greater economic benefits than the CCUS option. We reject this hypothesis: We found that the CCUS option will create greater economic and jobs benefits than the RE option. 3) The RE option will create more jobs per MW than the CCUS option. We reject this hypothesis: We found that the CCUS option will create more jobs per MW more than the RE option. We discuss the implications of these findings.

Analysis of Intermediate Temperature Combined Cycles With a Carbon Dioxide Topping Cycle

2008 ◽  
Author(s):  
R. Chacartegui ◽  
D. Sa´nchez ◽  
F. Jime´nez-Espadafor ◽  
A. Mun˜oz ◽  
T. Sa´nchez
Keyword(s):  
Carbon Dioxide ◽  
Power Plant ◽  
Gas Turbine ◽  
High Efficiency ◽  
Solar Power ◽  
Combined Cycle ◽  
Inlet Temperature ◽  
Pressure Drops ◽  
Combined Cycles ◽  
Topping Cycle

The development of high efficiency solar power plants based on gas turbine technology presents two problems, both of them directly associated with the solar power plant receiver design and the power plant size: lower turbine intake temperature and higher pressure drops in heat exchangers than in a conventional gas turbine. To partially solve these problems, different configurations of combined cycles composed of a closed cycle carbon dioxide gas turbine as topping cycle have been analyzed. The main advantage of the Brayton carbon dioxide cycle is its high net shaft work to expansion work ratio, in the range of 0.7–0.85 at supercritical compressor intake pressures, which is very close to that of the Rankine cycle. This feature will reduce the negative effects of pressure drops and will be also very interesting for cycles with moderate turbine inlet temperature (800–1000 K). Intercooling and reheat options are also considered. Furthermore, different working fluids have been analyzed for the bottoming cycle, seeking the best performance of the combined cycle in the ranges of temperatures considered.

Prediction of Soot Formation Trends in Turbulent Kerosene-Air Diffusion Jet Flames With Elevated Operating Pressure

2017 ◽  
Author(s):  
Pravin Nakod ◽  
Saurabh Patwardhan ◽  
Ishan Verma ◽  
Stefano Orsino
Keyword(s):  
Environmental Protection Agency ◽  
Volume Fraction ◽  
Soot Formation ◽  
Mixture Fraction ◽  
Soot Volume Fraction ◽  
Operating Pressure ◽  
Jet Flames ◽  
Emission Standard ◽  
Radial Profiles ◽  
Air Diffusion

Emission standard agencies are coming up with more stringent regulations on soot, given its adverse effect on human health. It is expected that Environmental Protection Agency (EPA) will soon place stricter regulations on allowed levels of the size of soot particles from aircraft jet engines. Since, aircraft engines operate at varying operating pressure, temperature and air-fuel ratios, soot fraction changes from condition to condition. Computation Fluid Dynamics (CFD) simulations are playing a key role in understanding the complex mechanism of soot formation and the factors affecting it. In the present work, soot formation prediction from numerical analyses for turbulent kerosene-air diffusion jet flames at five different operating pressures in the range of 1 atm. to 7 atm. is presented. The geometrical and test conditions are obtained from Young’s thesis [1]. Coupled combustion-soot simulations are performed for all the flames using steady diffusion flamelet model for combustion and Mass-Brookes-Hall 2-equation model for soot with a 2D axisymmetric mesh. Combustion-Soot coupling is required to consider the effect of soot-radiation interaction. Simulation results in the form of axial and radial profiles of temperature, mixture fraction and soot volume fraction are compared with the corresponding experimental measured profiles. The results for temperature and mixture fraction compare well with the experimental profiles. Predicted order of magnitude and the profiles of the soot volume fraction also compare well with the experimental results. The correct trend of increasing the peak soot volume fraction with increasing the operating pressure is also captured.

scholarly journals Analysis of roof greening technology impact on rain and meltwater retention

2020 ◽  
Vol 175 ◽  
pp. 11023
Author(s):  
Elena Sysoeva ◽  
Margarita Gelmanova
Keyword(s):  
High Efficiency ◽  
Green Roof ◽  
Experimental Studies ◽  
Green Roofs ◽  
Climatic Conditions ◽  
Water Runoff ◽  
Substrate Thickness ◽  
Runoff Reduction ◽  
The Usa ◽  
Analytical Review

Over the past 20 years, a large number of studies have been published on reducing storm runoff by various types of green roofs. This article analyzes the results of experimental studies presented in 39 publications on green roof runoff reduction in a climate similar to the climate of Russia: in Canada, the USA, Finland, Norway, France. An analytical review found that the ability of green roofs to retain rainfall varies from 20 to 99.5% depending on climatic conditions (duration and intensity of rains, duration of dry periods, solar radiation, temperature and humidity, wind conditions), the properties of green roof layers (moisture capacity of the substrate and a drainage layer, the substrate thickness), the type of vegetation, the geometry of a green roof (slope and orientation). Green roofs can be a useful tool for reducing urban storm water runoff. However, in order to ensure high efficiency, it is necessary to use green roof technology with other measures to reduce runoff.

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