CFD Simulation of a Low NOx Oil Fired Boiler

2005 ◽  
Author(s):  
C. Hochenauer ◽  
G. Brandstetter
Keyword(s):  
Cfd Simulation ◽  
Nox Reduction ◽  
Fuel Oil ◽  
Detailed Chemical Kinetics ◽  
Heavy Fuel Oil ◽  
Two Phase ◽  
Boiler Load ◽  
Excess Air ◽  
Wide Range ◽  
The Impact

This paper compares the results of an advanced CFD calculation with measurements of a heavy fuel oil fired low NOx boiler. First, a state of the art boiler was investigated and the impact of boiler load and excess air on the NOx emissions was measured. In a second test run a staged combustion technology was integrated using the over fire air concept. The over fire technology is well known and well tested in coal fired boilers. In this pilot boiler it was shown that the over fire air technology could be used for oil fired boilers, too — leading to an enormous NOx reduction without any increase in CO and soot emissions. It was shown that the influence of boiler load, excess air and over fire air on the NOx and CO emissions can be predicted very well in the CFD calculation. Detailed numerical investigations showed that two-phase effects, a good turbulence model, gas and soot radiation and a detailed chemical kinetics mechanism are a must when modeling (staged) heavy oil combustion. The results of the CFD calculation showed an excellent agreement with the measurements over a very wide range of boiler settings and load factors although NOx is extremely difficult to predict.

scholarly journals Robust component: a robustness measure that incorporates access to critical facilities under disruptions

2019 ◽  
Vol 16 (157) ◽  
pp. 20190149 ◽  
Author(s):  
Shangjia Dong ◽  
Haizhong Wang ◽  
Ali Mostafavi ◽  
Jianxi Gao
Keyword(s):  
Emergency Services ◽  
Network Robustness ◽  
Network Access ◽  
Two Phase ◽  
Earthquake Scenario ◽  
Degree Correlation ◽  
Wide Range ◽  
Critical Facilities ◽  
The Impact ◽  
Post Disaster

The objective of this paper is to integrate the post-disaster network access to critical facilities into the network robustness assessment, considering the geographical exposure of infrastructure to natural hazards. Conventional percolation modelling that uses generating function to measure network robustness fails to characterize spatial networks due to the degree correlation. In addition, the giant component alone is not sufficient to represent the performance of transportation networks in the post-disaster setting, especially in terms of the access to critical facilities (i.e. emergency services). Furthermore, the failure probability of various links in the face of different hazards needs to be encapsulated in simulation. To bridge this gap, this paper proposed the metric robust component and a probabilistic link-removal strategy to assess network robustness through a percolation-based simulation framework. A case study has been conducted on the Portland Metro road network during an M9.0 earthquake scenario. The results revealed how the number of critical facilities severely impacts network robustness. Besides, earthquake-induced failures led to a two-phase percolation transition in robustness performance. The proposed robust component metric and simulation scheme can be generalized into a wide range of scenarios, thus enabling engineers to pinpoint the impact of disastrous disruption on network robustness. This research can also be generalized to identify critical facilities and sites for future development.

scholarly journals SUSTAINABLE DEVELOPMENT AND ENERGY SECURITY LEVEL AFTER IGNALINA NPP SHUTDOWN

2011 ◽  
Vol 17 (1) ◽  
pp. 5-21 ◽  
Author(s):  
Juozas Augutis ◽  
Ričardas Krikštolaitis ◽  
Sigita Pečiulytė ◽  
Inga Konstantinavičiūtė
Keyword(s):  
Power Plant ◽  
Energy Security ◽  
Nuclear Power ◽  
Integral Characteristic ◽  
Fuel Oil ◽  
Electricity Production ◽  
Security Level ◽  
Heavy Fuel Oil ◽  
Security Indicators ◽  
The Impact

The paper presents the investigation of the impact of Ignalina Nuclear Power Plant (NPP) shutdown on Lithuanian energy security. The system of energy security indicators, covering technical, economic and socio-political aspects is presented. The integral characteristic of these indicators shows the level of energy security. The paper analyses the Lithuanian energy security level in 2007. To make a comparison, the energy security level in 2010, after the shutdown of Ignalina NPP, when Lithuanian Power Plant in Elektrėnai becomes the main electricity producer, is forecasted. Two alternatives are analysed: Lithuanian Power Plant uses either gas or heavy fuel oil for electricity production. The security level of each indicator, each indicator block and the total security level are presented as the result. Energy security indicators, which increased or decreased after the shutdown of Ignalina NPP, are analysed, including the indicators which have had the greatest impact on the change in energy security level. The influence of Ignalina NPP shutdown on CO2 emissions is presented. Also, electricity generating costs for different types of electricity production at a different discount rate are presented.

scholarly journals Declines in EROI of Main Fuels and the Implications on Developing LNG as a Marine Fuel

2020 ◽  
Vol 8 (9) ◽  
pp. 719
Author(s):  
Mohammad Vaferi ◽  
Kayvan Pazouki ◽  
Arjen Van Klink
Keyword(s):  
Net Present Value ◽  
Capital Expenditure ◽  
Investment Decision ◽  
Engine Performance ◽  
Fuel Oil ◽  
Second Phase ◽  
Heavy Fuel Oil ◽  
Marine Fuel ◽  
Non Linear System ◽  
The Impact

This article proposes an analytical model for a conversion from Heavy Fuel Oil (HFO) to Liquide Natural Gas(LNG) dual-fuel engine in a fleet with three sizes of vessels in order to investigate the impact of the volatility of oil prices, and a declining Energy Return on Investment (EROI) on opting LNG as a reliable marine fuel. This study also attempts to echo the importance of looking through a new window to the process of energy opting in the maritime industries to comply with International Maritime Organization (IMO) regulations. With giving this awareness to the maritime society the new investment can be directed to resources that effectively keep the maritime economy growing and can also help build a sustainable future. In order to find the best answer, we need to seek alternative solutions that will sustain shipping’s competitive edge. In the first phase, the impact of a declining EROI gas is investigated. Then, in the second phase, to be able to find an optimal area to run the vessels, we apply the Computerized Engine Application System (CEAS) in order to predict the engine performance of different container vessels and outlined fuel consumption in various market and technical situations. Since the process found is a non-linear system, this paper attempts to investigate the ongoing trend of the EROI of LNG in applying a Net Present Value (NPV) as a simulation method in order to observe the system to which technical variables or legal frameworks is more sensitive. In the following order, we first characterise the uncertainty faced by policy-makers and complexity dynamics implications for investment decision-makers and technology adoption. The practical relevance here of the proposed applied methodology is subsequently discussed in reference to four scenarios relating to the above areas and introduces the most beneficial area between different vital variables and constraints. It is applicable for the management of cascading uncertainties and the cross-sectoral impact by introducing the most beneficial area between various vital variables and constraints; including LNG prices, Capital Expenditure (Capex), Operating Expenditure(Opex) and time of enforcement.

Diesel Engine NOx Reduction Using Charge Air Water Injection

2005 ◽  
Author(s):  
Ernst Radloff ◽  
Charles Gautier
Keyword(s):  
Fuel Consumption ◽  
Nox Reduction ◽  
Water Injection ◽  
Fuel Oil ◽  
Emissions Reduction ◽  
Nox Emissions ◽  
Test Results ◽  
Marine Diesel ◽  
Marine Vessels ◽  
The Impact

The Transportation Development Centre of Transport Canada, in collaboration with Environment Canada’s Emissions Research and Measurement Division, conducted a series of emissions tests onboard the Oceanex RoRo vessel MV Cabot operating between Montre´al, Quebec, and St. John’s, Newfoundland. The primary objectives were to verify emissions inventories and demonstrate the feasibility of installing affordable emissions reduction technology on marine vessels as well as compliance with future regulatory emissions limits. The tests also provided an opportunity for Canada to share information on emissions program and technology developments with U.S. regulatory authorities. This may lead to developing joint emissions reduction initiatives for existing marine vessels. This paper describes the field-testing of a water injection system (WIS) to reduce oxides of nitrogen (NOx) emissions from ocean-going vessels. Tests were conducted on a semi-dedicated basis during voyage and under steady-state conditions. The emissions measurements were taken in accordance with ISO 8178-4-E3 protocol and using both marine diesel oil and intermediate fuel oil, which enabled the evaluation of the impact of different fuel type and quality on emissions. An initial series of tests was carried out on the MV Cabot in March 2004, followed by a second series of tests on the same vessel in March 2005. These tests demonstrated the effectiveness of a low-cost WIS for reducing NOx emissions in marine diesel engines. They also showed that water injection reduces NOx at the expense of an increase in both particulate matter and carbon monoxide when using intermediate fuel oil. NOx reductions varied between 10 and 35 percent, and were most effective at high water injection ratios above 50 percent engine load. The test results showed no negative impact of the WIS on fuel consumption or engine operation and performance. This paper compares the results obtained from the consecutive series of tests in terms of the effectiveness of NOx reduction, and analyses the results in the context of other full-scale test results obtained from emissions control system vendors and engine suppliers. It also investigates the theoretical process and technology of water injection through charge air fumigation, and both direct water and fuel/water emulsion injection. In addition, the effects of water injection on engine emissions, operation and maintenance, and the optimization of water injection from a knowledge-based perspective are discussed. Further testing and development of the WIS are required to realize optimal emissions reduction potential and to determine the impact of water injection on fuel consumption, and engine operational performance as well as the impact of fuel quality on emissions.

scholarly journals Comparative toxicity assessment of in situ burn residues to initial and dispersed heavy fuel oil using zebrafish embryos as test organisms

2020 ◽  
Author(s):  
Sarah Johann ◽  
Mira Goßen ◽  
Leonie Mueller ◽  
Valentina Selja ◽  
Kim Gustavson ◽  
...  
Keyword(s):  
Scientific Information ◽  
Fuel Oil ◽  
Zebrafish Embryos ◽  
Life Stages ◽  
Biological Organization ◽  
Heavy Fuel Oil ◽  
Toxic Response ◽  
Chemical Dispersant ◽  
The Impact

AbstractIn situ burning (ISB) is discussed to be one of the most suitable response strategies to combat oil spills in extreme conditions. After burning, a highly viscous and sticky residue is left and may over time pose a risk of exposing aquatic biota to toxic oil compounds. Scientific information about the impact of burn residues on the environment is scarce. In this context, a comprehensive ISB field experiment with approx. 1000L IFO 180 was conducted in a fjord in Greenland. The present study investigated the toxicity of collected ISB residues to early life stages of zebrafish (Danio rerio) as a model for potentially exposed pelagic organisms. The toxicity of ISB residues on zebrafish embryos was compared with the toxicity of the initial (unweathered) IFO 180 and chemically dispersed IFO 180. Morphological malformations, hatching success, swimming behavior, and biomarkers for exposure (CYP1A activity, AChE inhibition) were evaluated in order to cover the toxic response on different biological organization levels. Across all endpoints, ISB residues did not induce greater toxicity in zebrafish embryos compared with the initial oil. The application of a chemical dispersant increased the acute toxicity most likely due to a higher bioavailability of dissolved and particulate oil components. The results provide insight into the adverse effects of ISB residues on sensitive life stages of fish in comparison with chemical dispersant application.

scholarly journals High Space Heat Release and Low Excess Air Combustion of Heavy Fuel Oil Using Exhaust Gas Recirculation Method

1969 ◽  
Vol 12 (51) ◽  
pp. 530-538
Author(s):  
Mutsuo KOIZUMI ◽  
Hirokazu MIZUTANI ◽  
Yoshihiko TAKAMURA ◽  
Katsuya NAGATA
Keyword(s):  
Heat Release ◽  
Exhaust Gas Recirculation ◽  
Fuel Oil ◽  
Exhaust Gas ◽  
Heavy Fuel Oil ◽  
Excess Air ◽  
High Space ◽  
Gas Recirculation

Fuel Oil Reburning Application for NOx Control to Firetube Package Boilers

1987 ◽  
Vol 109 (2) ◽  
pp. 207-214 ◽  
Author(s):  
J. A. Mulholland ◽  
R. E. Hall
Keyword(s):  
Natural Gas ◽  
Nitrogen Content ◽  
Nox Reduction ◽  
Pilot Scale ◽  
Fuel Oil ◽  
Limiting Factor ◽  
Boiler Load ◽  
Residual Fuel Oil ◽  
Nox Control ◽  
Percent Nitrogen

Two pilot-scale (0.73 MW or 2.5 × 106 Btu/hr) firetube package boilers were retrofitted for fuel oil reburning application for NOx emission control. When firing distillate fuel oil (0.01 percent nitrogen content), an overall NOx reduction of 46 percent from an uncontrolled emission of 125 ppm (dry, at zero percent O2) was realized by diverting 20 percent of the total boiler load to a second stage burner; a 51 percent NOx reduction from 265 ppm was achieved in a distillate/residual fuel oil mixture (0.14 percent nitrogen content) reburning application. Nitrogen-free fuel oil reburning was found to be slightly more effective at reducing NOx than was natural gas reburning, although longer fuel-rich zone residence times were required to allow for evaporation and mixing of the fuel oil droplets. Key parameters investigated which impact the reburning process were: primary flame NOx, reburn zone stoichiometry, and reburn zone residence time. Reburning applied to firetube package boilers requires minimal facility modification. Reburning can be coupled with other NOx control techniques (e.g., distributed air low NOx burners) to achieve NOx emissions of less than 100 ppm. However, for very low primary flame NOx conditions (i.e., less than 200 ppm), reburning fuel nitrogen content is a limiting factor, and reburning with a low-nitrogen-content fuel, such as natural gas or nitrogen-free distillate oil, may be necessary to achieve 50 percent NOx reduction.

scholarly journals Characterization of the Solid Particle Erosion of the Sealing Surface Materials of a Ball Valve

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 263
Author(s):  
Donghua Peng ◽  
Shaohua Dong ◽  
Zhiqiang Wang ◽  
Dongying Wang ◽  
Yinuo Chen ◽  
...  
Keyword(s):  
Erosion Rate ◽  
Cfd Simulation ◽  
Two Phase Flow ◽  
Simulation Analysis ◽  
Impact Angle ◽  
Ball Valve ◽  
Phase Flow ◽  
Two Phase ◽  
Valve Sealing ◽  
The Impact

The ball valve is an essential piece of equipment in an oil and gas pipeline. The sand particles transported through the pipeline can cause erosion and wear to the ball valve, thus causing it to fail, leading to serious safety hazards. In this paper, the self-designed erosion experiment method was combined with computational fluid dynamics (CFD), while the Euler-Lagrange method was also introduced to optimize the Oka erosion model and Ford particle-wall rebound model. The erosion mechanism and characteristics of the ball valve sealing surface in gas-solid two-phase flow were simulated, while the erosion condition of the specimen was analyzed and compared when exposed to different factors, such as different particle velocities, impact angle, particle size, and specimen materials. The experimental data conformed well to the CFD erosion simulation data, verifying the accuracy of the CFD simulation analysis. The results indicated that the worn surface was caused by various wear mechanisms, while a “stagnation zone” was identified at the center of the specimen. The maximum erosion area, which was U-shaped, was also located at the center. The erosion rate increased in conjunction with an increase in the particle velocity and size, both of which failed to affect the erosion pattern. The erosion rate initially increased, after which it decreased with the impact angle, reaching the maximum value at an impact angle of 30°. This paper summarizes the erosion failure mechanism and characteristics in gas–solid two-phase flow and provides both technical support and a theoretical basis for the on-site maintenance of essential vulnerable parts in the pipeline, such as ball valves.

scholarly journals Eco-Efficiency Assessment of the Application of Large-Scale Rechargeable Batteries in a Coal-Fired Power Plant

Energies ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1384 ◽  
Author(s):  
Piotr Krawczyk ◽  
Anna Śliwińska
Keyword(s):  
Power Plant ◽  
Large Scale ◽  
Fossil Fuels ◽  
Economic Benefits ◽  
Fuel Oil ◽  
Electricity Production ◽  
Hard Coal ◽  
Heavy Fuel Oil ◽  
Efficiency Assessment ◽  
The Impact

This article presents the results of an eco-efficiency assessment of the application of large-scale rechargeable battery technology in electricity generation from coal. The eco-efficiency of electricity production in a 350 MW coal-fired power plant was calculated. Two production variants were compared: with the use of a lithium-ion battery of a 400 MWh capacity to optimize the operation of power blocks and without using the battery. Hard coal is one of the main fossil fuels used to generate electricity in Poland. Despite the growing share of electricity from renewable sources, this situation will persist for many more years. The main reasons for this are the high costs and long-lasting process of moving away from fossil fuels in the energy sector. Therefore, any technical solutions that can temporarily reduce the negative impact of coal-based power engineering on the environment should be considered. At the same time, the economic aspects of such solutions must be taken into account. That is why the eco-efficiency assessment method was chosen, which integrates economic and environmental aspects. The obtained results of the analyses indicate the occurrence of environmental and economic benefits resulting from the use of the battery in coal-fired power plants. It has been found that battery-based technology is more eco-efficient than technology without such a battery. A sensitivity analysis was carried out, which allowed the impact of individual computational variables on the eco-efficiency assessment result to be assessed. The results indicate that fuel prices (coal and heavy fuel oil—mazout) and CO2 emission allowances have the greatest impact on the eco-efficiency of the analyzed technology. It was also found that the factors related to the battery, such as its efficiency, life span, decrease of the capacity after 10 years of operation, and construction cost, have a much smaller impact on the results.

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