Retrofit of WtE Boiler: Case Study on Bonn Plant

2002 ◽  
Author(s):  
Mark Pe´rilleux ◽  
Dirk Eeraerts
Keyword(s):  
Flue Gas ◽  
Gas Flow ◽  
Natural Circulation ◽  
Combustion Process ◽  
Circulation System ◽  
Gas Temperature ◽  
Complete Combustion ◽  
Parallel Flows ◽  
Secondary Air Injection ◽  
Secondary Air

The implementation of the European-directive requiring a residence time of at least two seconds at a temperature above 850°C (1562°F), the change in waste characteristics, and the pursuit of higher thermal efficiencies has pushed many of the existing WtE plants in Europe to their operational limits. Most existing WtE plants were not designed to operate under these conditions and may require modifications to the combustion system. Within the SEGHERS better technology (SEGHERS) company, the SEGHERS-IBB-Prism was developed to deal with the cause of these problems, which are essentially related to insufficient mixing and burnout of the flue gases in the combustion area. In the Boiler Prism the flue gas flow is divided into two parallel flows prior to entering the first radiant pass of the boiler. This division is achieved by means of a prism shaped construction, which is water-cooled and integrated with the natural circulation system of the boiler. Additional secondary air injection nozzles are fitted in the prism. This technology results in a more uniform flue gas temperature and a complete combustion of the flue gas immediately above the prism. In the Bonn Plant, these improvements in the combustion process resulted in a decrease of the fireside cleaning requirements of more than 50%.

scholarly journals Investigations of combustion process in combined cooker-boiler fired on solid fuels

2006 ◽  
Vol 10 (4) ◽  
pp. 121-130
Author(s):  
Dragoslava Stojiljkovic ◽  
Vladimir Jovanovic ◽  
Milan Radovanovic ◽  
Nebojsa Manic ◽  
Ivo Radulovic
Keyword(s):  
Flue Gas ◽  
Combustion Process ◽  
Solid Fuels ◽  
Gas Temperature ◽  
Weight Changes ◽  
Complete Combustion ◽  
Air Supply ◽  
Class 1 ◽  
Secondary Air ◽  
Co Emission

The aim of the investigation was to make some reconstructions on the existing stove used for cooking and baking and to obtain the combined cooker-boiler which will fulfill the demands of European standard EN 12815. Implementation of modern scientific achievements in the field of combustion on stoves and furnaces fired on solid fuels was used. During the investigations four various constructions were made with different fresh air inlet and secondary air supply with the intention to obtain more complete combustion with increased efficiency and reduced CO emission. Three different fuels were used: firewood, coal, and wood briquette. A numerous parameters were measured: fuel weight changes during the combustion process, temperature of inlet and outlet water, flue gas composition (O2, CO, SO2, CO2, NOx), flue gas temperature, ash quantity etc. The result of the investigations is the stove with the efficiency of more than 75% - boiler Class 1 (according EN 12815) and CO emission of about 1% v/v. The results obtained during the measurements were used as parameters for modeling of combustion process. .

Waste Combustion Technology and Air Emission Control Developments by Fisia Babcock Environment

2011 ◽  
Author(s):  
Jens Sohnemann ◽  
Walter Scha¨fers ◽  
Armin Main
Keyword(s):  
Flue Gas ◽  
Combustion Process ◽  
Great Majority ◽  
Optimum Process ◽  
Cleaning Process ◽  
Gas Temperature ◽  
Flash Evaporation ◽  
Limit Values ◽  
Gas Cleaning ◽  
Secondary Air

The efforts for reducing the emissions into the atmosphere start already in the furnace and are completed by an effective flue gas cleaning system. This implies the necessity for design developments of key components for a modern EfW plant. For the core component of the firing system — the grate — Fisia Babcock Environment (FBE) is using forward moving grates as well as roller grates. The moving grate, which is used in the great majority of all our plants, has specific characteristics for providing uniform combustion and optimal burnout. These include, amongst others: - Uniform air supply by means of specific grate bar geometry. - Two grate steps in direction of waste transport for optimum burnout. - Flexible adaptation of the combustion process to the respective conditions and requirements by zone-specific air distribution and transport velocity of waste on grate. - Combustion control adapted to the specific plant for ensuring a consistent combustion process and production of energy. In addition to these features influencing the emissions the moving grate exhibits also specific characteristics regarding the mechanical aspects allowing low-maintenance and reliable operation. For optimum flue gas burnout a good oxygen distribution after leaving the combustion zone is required. For ensuring this, the injection of secondary air is designed to produce a double-swirl, developed by FBE. Final reduction of the nitrogen constituents NO and NO2 to the stipulated emission value is achieved by the SNCR process. As well in this respect, there is a great amount of experience available. Besides these measures regarding the combustion process, this paper also reports about flue gas cleaning systems. In this field the FBE CIRCUSORB® process is presented and compared with the known dry absorption process. CIRCUSORB® is a lime-based flue gas cleaning process with continuous recirculation of the moistened reaction product and simultaneous addition of fresh hydrated lime. The flue gas temperature downstream of the economizer can be selected very low and permits in this way maximized utilization of the energy. The evaporation of the moisture from the reaction product (flash evaporation) effects final cooling down of the flue gas to optimum process temperature and improves at the same time SO2 separation. This reduces the technical investment required for the flue gas cleaning process. The total of all measures taken and the robust design of all components permit economical plant operation while complying with the stipulated emission limit values.

scholarly journals Quality Function Deployment (QFD) and TRIZ in Briquette Cookstove Design and Simulation

2021 ◽  
Vol 12 (2) ◽  
pp. 349-359
Author(s):  
Niswatun Faria ◽  
◽  
Kuntum Khoiro Ummatin ◽  
Mochammad Annas Junianto ◽  
Tedy Eko Budiharso
Keyword(s):  
Flue Gas ◽  
Quality Function Deployment ◽  
Computational Simulation ◽  
Combustion Process ◽  
Combustion Efficiency ◽  
Concept Design ◽  
Complete Combustion ◽  
Air Inlet ◽  
Secondary Air ◽  
Chamber Capacity

Poor cookstove design can harm the user's health and environment. This research aims to obtain an efficient cookstove design, environmentally friendly and operated easily. The cookstove design process using a combination of QFD and TRIZ. QFD able to capture customer needs through a questionnaire and interview. The data collected then processed to build a House of Quality (HoQ), one of the tools in QFD. QFD results in the design parameter of the briquette cookstove, which is incorporated in the concept design. The TRIZ method is utilized to understand the problem that might occur in the concept design and focus on solving the root causes. The next step is a detailed design where the dimensions, combustion chamber capacity, and supporting features are explained. The combination of QFD and TRIZ result in a briquette cookstove concept design which is easy to clean and operate. The combustion system is Top-lit Up-Draft (TLUD). The burning chamber has two air inlets, namely primary and secondary. The primary air inlet supplies the air from the bottom of the burning chamber, partially burns the briquette, and produces flue gas. The secondary air inlet is in the shape of an oval to supply air in the burning chamber's upper part to burn the flue gas completely. A complete combustion process will increase combustion efficiency and reduce emissions. A computational simulation shows the velocity distribution inside the burning chamber.

scholarly journals Dependence of the Flue Gas Flow on the Setting of the Separation Baffle in the Flue Gas Tract

2021 ◽  
Vol 11 (7) ◽  
pp. 2961
Author(s):  
Nikola Čajová Kantová ◽  
Alexander Čaja ◽  
Marek Patsch ◽  
Michal Holubčík ◽  
Peter Ďurčanský
Keyword(s):  
Particulate Matter ◽  
Flue Gas ◽  
Gas Flow ◽  
Negative Impact ◽  
Combustion Process ◽  
Cfd Simulations ◽  
Piv Measurements ◽  
Computational Fluid Dynamics Cfd ◽  
Particle Imaging ◽  
Combustion Of Solid Fuels

With the combustion of solid fuels, emissions such as particulate matter are also formed, which have a negative impact on human health. Reducing their amount in the air can be achieved by optimizing the combustion process as well as the flue gas flow. This article aims to optimize the flue gas tract using separation baffles. This design can make it possible to capture particulate matter by using three baffles and prevent it from escaping into the air in the flue gas. The geometric parameters of the first baffle were changed twice more. The dependence of the flue gas flow on the baffles was first observed by computational fluid dynamics (CFD) simulations and subsequently verified by the particle imaging velocimetry (PIV) method. Based on the CFD results, the most effective is setting 1 with the same boundary conditions as those during experimental PIV measurements. Setting 2 can capture 1.8% less particles and setting 3 can capture 0.6% less particles than setting 1. Based on the stoichiometric calculations, it would be possible to capture up to 62.3% of the particles in setting 1. The velocities comparison obtained from CFD and PIV confirmed the supposed character of the turbulent flow with vortexes appearing in the flue gas tract, despite some inaccuracies.

Integrated modeling of coking flue gas indices based on mechanism model and improved neural network

2018 ◽  
Vol 41 (1) ◽  
pp. 85-96
Author(s):  
Yaning Li ◽  
Xuelei Wang ◽  
Jie Tan
Keyword(s):  
Neural Network ◽  
Adaptive Learning ◽  
Flue Gas ◽  
Gas Flow ◽  
Rbf Neural Network ◽  
Combustion Process ◽  
Material Balance ◽  
Integrated Modeling ◽  
Flow Diagram ◽  
Mechanism Model

Focusing on the first domestic coking flue gas desulfurization and denitration integrated unit in China, the current condition of inlet flue gas indices cannot be determined timely owing to the large detection lag and complex upstream coking process, which is extremely unfavorable for the optimal control of desulfurization and denitration process. In order to solve this problem, an intelligent integrated modeling method of flue gas SO2 concentration, O2 content and NOx concentration is proposed. Firstly, the gas flow diagram in combustion process is built, the mechanism models of SO2, NOx concentration and O2 content are established according to the principle of material balance and reaction kinetics, respectively. Then the RBF neural network is adopted to compensate the prediction error, an improved training algorithm combining optimal stopping principle and dual momentum adaptive learning rate is proposed to improve the training speed and generalization ability of neural network. Based on the practical data of two 55-hole and 6-meter top charging coke ovens in the coking group, the effectiveness and superiority of proposed model and method are verified by simulation via comparison of various methods.

Energy-Saving Analysis of 215MW Cogeneration Boiler Adding Low Temperature Economizer

2013 ◽  
Vol 448-453 ◽  
pp. 2777-2780 ◽  
Author(s):  
Yan Feng Liu ◽  
Shi Ping Li ◽  
Xiang Hong Li
Keyword(s):  
Low Temperature ◽  
Flue Gas ◽  
Waste Heat ◽  
Natural Circulation ◽  
Peak Load ◽  
Exhaust Gas ◽  
Gas Temperature ◽  
Bag Filter ◽  
Actual Operation ◽  
Exhaust Gas Temperature

A 215MW cogeneration B&W670/13.7-M type high-pressure natural circulation boilers, the exhaust gas temperature is set as 143 °C, while in the actual operation, the average exhaust gas temperature is 155 °C, and when the unit is running at full capacity in summer the highest exhaust gas temperature is 169.6 °C. In order to satisfy the normal operating temperature of bag filter in summer peak load, and recover low temperature waste heat of fule gas, low temperature economizer is added to the thermal system. Therefore, low-temperature economizers are respectively added in four flues which are between the outlet of the air preheater and the entrance of the bag filter, this will achieve the purpose of reducing flue gas temperature by transferring heat between condensate and flue gas, ensuring the units safe operating and improving the overall operating performance of the boiler.

The Partition Period of Thermodynamic Calculation and the Numerical Simulation for Lignite Blended Supercritical Boiler

2014 ◽  
Vol 1030-1032 ◽  
pp. 648-652
Author(s):  
Cai Ying Ban ◽  
Xu Ao Lu ◽  
Jian Meng Yang ◽  
Xu Ran ◽  
Feng Ying Liang
Keyword(s):  
Numerical Simulation ◽  
Flue Gas ◽  
Thermodynamic Calculation ◽  
Heat Load ◽  
Combustion Process ◽  
Heating Surface ◽  
Gas Temperature ◽  
Boiler Furnace ◽  
Geometry Model ◽  
The Impact

The purpose of this paper is to study the impact of furnace temperature and load after blending in lignite, based on CFD software FLUENT-6.3,this paper choose the appropriate geometry model and the physical and mathematical models, and numerical simulation of the different conditions 600MW supercritical once-through boiler blending lignite furnace combustion process is curried out. And through a 600MW supercritical coal-fired boiler furnace lignite blended performed sections thermodynamic calculation under different conditions, worked out the furnace flue gas temperature, CO, CO2concentration distribute trend and radiant heat each section surface heat load conditions. The specific amount were blended with 5%, 10%, 15%, 20% were not dried lignite and dried lignite 20% after five conditions. And obtained a conclusion is the temperature and radiation heating surface flue gas heat load in the overall trend under the various conditions.

Numerical Simulation of Combustion Process in a 350t/d MSW Incinerator

2012 ◽  
Vol 268-270 ◽  
pp. 898-901
Author(s):  
Shui E Yin ◽  
Jun Wu
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Combustion Process ◽  
Species Distributions ◽  
Complete Combustion ◽  
Operational Conditions ◽  
Furnace Outlet ◽  
Air Supply ◽  
Total Temperature ◽  
Secondary Air

A mathematical model was presented for the combustion of municipal solid waste in a 350t/d MSW-burning incinerator. Numerical simulations were performed to predict the temperature and the species distributions in the furnace, with practical operational conditions taken into account. When the total air supply is constant, reducing primary air and increasing secondary air properly results in the higher total temperature of the furnace and the more oxygen concentration at the furnace outlet, and thereby contributes to the complete combustion of combustibles so that an optimal combustion effect can be achieved.

scholarly journals Gas Combustion Efficiency Enhancement: Application Study of Intense Elestrostatic Field

2019 ◽  
Vol 56 (4) ◽  
pp. 3-16
Author(s):  
O. Krickis ◽  
N. Zeltins
Keyword(s):  
Electrostatic Field ◽  
Flue Gas ◽  
Combustion Process ◽  
Field Application ◽  
Process Efficiency ◽  
Simultaneous Increase ◽  
Efficiency Enhancement ◽  
Gas Temperature ◽  
Gas Combustion ◽  
The Impact

Abstract A number of international, European Union and Latvian legislative acts have been developed, which regulate the efficiency of gas combustion plants and greenhouse gas emissions in the atmosphere. These legislative acts require the development of new scientifically efficient methods for gas optimal combustion with a minor impact on the environment. In order to achieve such a goal, different methods can be used, but the most efficient is an intensive electrostatic field application to control combustion and harmful emission formation in premixed flames. In the framework of the current study, the authors developed a hybrid burner, which allowed generating an intensive electrostatic field with intensity of more than 1000 kV/m. The study also investigated the impact of such a field on the formation of harmful emissions, including CO2 and flue gas temperature. The empirical results showed that an intensive DC electrostatic field generated inside of the burner had an impact on the flame shape, CO2, NOx emissions and flue gas temperature. In its turn, by applying an intensive pulsating electrostatic field (multivariable experiment) it was possible to achieve the reduction in NOx, CO emissions with a simultaneous increase in flue gas temperature, which was related to combustion process efficiency enhancement.

IGNITION CONDITIONS OF A SINGLE BORON PARTICLE IN HOT GAS FLOW

2020 ◽  
Author(s):  
G. V. Ermolaev ◽  
◽  
A. V. Zaitsev ◽  
Keyword(s):  
Oxygen Concentration ◽  
Gas Flow ◽  
Flame Temperature ◽  
Combustion Process ◽  
Experimental Studies ◽  
Gas Temperature ◽  
Hot Gas ◽  
Combustion Models ◽  
Boron Particle ◽  
Boron Particles

The basic experimental studies on boron combustion are done with the same general scheme of the experiment. Boron particles are injected into flat-flame burner products with the help of the transporting jet of cold nitrogen. Boron particle combustion process is registered with a number of optical methods. It is proposed that boron particle is injected into the main hot gas flow instantly, combustion takes place at the flame temperature and predefined oxygen concentration, and the influence of the transporting cold nitrogen jet is ignored. Recent combustion models are based mostly on this type of experiments and characterized with high complexity and low prediction level. In our study, we reconstruct the particle injection conditions for several basic experimental papers. It is shown that in all experimental setups, ignition, combustion, and even total particle burnout take place in the wake of the cold nitrogen jet. This zone is characterized with a much lower gas temperature and oxygen concentration than the main flat burner flow. The total temperature decrease can be about several hundred degrees, oxygen concentration can be 30%-50% lower than that used in the previous analysis of the experimental results. The temperatures of ignition and transition to the second stage of combustion are found with the help of the test particle trajectory and temperature tracking. It is shown that analysis of the influence of boron particles injection on gas temperature and oxygen concentration is mandatory for the development of future combustion models.

Sign in / Sign up

Export Citation Format

Share Document