scholarly journals CFD Simulation of Fuel/flue Gas Section of the Fire-tube Steam Boiler System

2020 ◽  
Author(s):  
P Sai Pavan Kalyan ◽  
Amol Deshpande
Keyword(s):  
Flue Gas ◽  
Cfd Simulation ◽  
Steam Boiler

Numerical simulation and field test study of desulfurization wastewater evaporation treatment through flue gas

2014 ◽  
Vol 70 (7) ◽  
pp. 1285-1291 ◽  
Author(s):  
Jia-jia Deng ◽  
Liang-ming Pan ◽  
De-qi Chen ◽  
Yu-quan Dong ◽  
Cheng-mu Wang ◽  
...  
Keyword(s):  
Field Test ◽  
Flue Gas ◽  
Cfd Simulation ◽  
Electrostatic Precipitator ◽  
Negative Impact ◽  
Positive Impact ◽  
Field Tests ◽  
Gas Temperature ◽  
Simulation Results ◽  
Desulfurization Wastewater

Aimed at cost saving and pollution reduction, a novel desulfurization wastewater evaporation treatment system (DWETS) for handling wet flue gas desulfurization (WFGD) wastewater of a coal-fired power plant was studied. The system's advantages include simple process, and less investment and space. The feasibility of this system has been proven and the appropriate position and number of nozzles, the spray droplet size and flue gas temperature limitation have been obtained by computational fluid dynamics (CFD) simulation. The simulation results show that a longer duct, smaller diameter and higher flue gas temperature could help to increase the evaporation rate. The optimal DWETS design of Shangdu plant is 100 μm droplet sprayed by two nozzles located at the long duct when the flue gas temperature is 130 °C. Field tests were carried out based on the simulation results. The effects of running DWETS on the downstream devices have been studied. The results show that DWETS has a positive impact on ash removal efficiency and does not have any negative impact on the electrostatic precipitator (ESP), flue gas heat exchanger and WFGD. The pH values of the slurry of WFGD slightly increase when the DWETS is running. The simulation and field test of the DWETS show that it is a feasible future technology for desulfurization wastewater treatment.

CFD simulation of fine particle removal in flue gas condensing heat exchanger

2020 ◽  
Vol 174 ◽  
pp. 115290 ◽  
Author(s):  
Kai Li ◽  
Enlu Wang ◽  
Qi Wang ◽  
Naveed Husnain ◽  
Deli Li
Keyword(s):  
Heat Exchanger ◽  
Flue Gas ◽  
Fine Particle ◽  
Cfd Simulation ◽  
Particle Removal ◽  
Condensing Heat Exchanger

scholarly journals CFD Simulation of Pollutant Emission in a Natural Draft Dry Cooling Tower with Flue Gas Injection: Comparison between LES and RANS

Energies ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3630
Author(s):  
Guangjun Yang ◽  
Xiaoxiao Li ◽  
Li Ding ◽  
Fahua Zhu ◽  
Zhigang Wang ◽  
...  
Keyword(s):  
Flow Field ◽  
Flue Gas ◽  
Cooling Tower ◽  
Cfd Simulation ◽  
Concentration Field ◽  
Pollutant Concentration ◽  
Pollutant Emission ◽  
Navier Stokes ◽  
Dry Cooling Tower ◽  
Reynolds Average

Accurate prediction of pollutant dispersion is vital to the energy industry. This study investigated the Computational Fluid Dynamics (CFD) simulation of pollutant emission in a natural draft dry cooling tower (NDDCT) with flue gas injection. In order to predict the diffusion and distribution characteristics of the pollutant more accurately, Large Eddy Simulation (LES) was applied to predict the flow field and pollutant concentration field and compared with Reynolds Average Navier-Stokes (RANS) and Unsteady Reynolds Average Navier-Stokes (URANS). The relationship between pollutant concentration pulsation and velocity pulsation is emphatically analyzed. The results show that the flow field and concentration field simulated by RANS and URANS are very close, and the maximum value of LES is about 43 times that of RANS and URANS for the prediction of pollutant concentration in the inner shell of cooling tower. Pollutant concentration is closely related to local flow field velocity. RANS and URANS differ greatly from LES in flow field prediction, especially at the outlet and downwind of cooling tower. Compared with URANS, LES can simulate flow field pulsation with a smaller scale and higher frequency.

Methods of Thermal Calculations for a Condensing Waste-Heat Exchanger

2014 ◽  
Vol 35 (4) ◽  
pp. 447-461 ◽  
Author(s):  
Paweł Rączka ◽  
Kazimierz Wójs
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Water Vapour ◽  
Flue Gas ◽  
Waste Heat ◽  
Pilot Scale ◽  
Dew Point ◽  
Steam Boiler ◽  
Heat Transfer Area ◽  
Condensing Heat Exchanger

Abstract The paper presents the algorithms for a flue gas/water waste-heat exchanger with and without condensation of water vapour contained in flue gas with experimental validation of theoretical results. The algorithms were used for calculations of the area of a heat exchanger using waste heat from a pulverised brown coal fired steam boiler operating in a power unit with a capacity of 900 MWe. In calculation of the condensing part, the calculation results obtained with two algorithms were compared (Colburn-Hobler and VDI algorithms). The VDI algorithm allowed to take into account the condensation of water vapour for flue gas temperatures above the temperature of the water dew point. Thanks to this, it was possible to calculate more accurately the required heat transfer area, which resulted in its reduction by 19 %. In addition, the influence of the mass transfer on the heat transfer area was taken into account, which contributed to a further reduction in the calculated size of the heat exchanger - in total by 28% as compared with the Colburn-Hobler algorithm. The presented VDI algorithm was used to design a 312 kW pilot-scale condensing heat exchanger installed in PGE Belchatow power plant. Obtained experimental results are in a good agreement with calculated values.

scholarly journals Efficiency of Installation of an Additional Gas-Air Heat Exchanger When Operating a Steam Boiler on Gas and Liquid Fuel

2021 ◽  
Vol 2096 (1) ◽  
pp. 012011
Author(s):  
F Bakirov ◽  
E Ibragimov
Keyword(s):  
Flue Gas ◽  
Heat Exchangers ◽  
Liquid Fuel ◽  
Fuel Efficiency ◽  
Operating Mode ◽  
Payback Period ◽  
Fuel Oil ◽  
Technical Solution ◽  
Steam Boiler ◽  
Gas Temperature

Abstract The article presents the results of calculating the efficiency of reconstruction of the gas and air paths of a steam boiler when working on gas and liquid fuel due to the installation of additional gas-air heat exchangers. Due to the utilization of the thermal energy of the flue gases in the newly installed heat exchangers, the air is heated in front of the boiler air heaters and the fuel efficiency is increased by increasing the boiler efficiency. The increase in the efficiency of the "gross" boiler during the operation of the considered TGM-84 boiler on fuel oil with an average annual operating mode was 2.81 %. The flue gas temperature after the boiler air heaters was 178 °C, and the air temperature at the inlet to the air heaters was 99 °C at the average annual load of the boiler, which ensures an almost corrosion-free operation of the air heater packing. It is revealed that when the liquid fuel boilers, installation of new heat exchangers and their strapping on the side of the air and flue gas has a shorter payback period than the boiler gas fired. The simple payback period of the considered technical solution was 6,82 years when working on gas fuel and 1,35 years when working on liquid fuel.

scholarly journals A Pulverized Coal-Fired Boiler Optimized for Oxyfuel Combustion Technology

10.14311/1588 ◽  
2012 ◽  
Vol 52 (4) ◽  
Author(s):  
Tomáš Dlouhý ◽  
Tomáš Dupal ◽  
Jan Dlouhý
Keyword(s):  
Power Plant ◽  
Flue Gas ◽  
Gas Flow ◽  
Operating Mode ◽  
Pulverized Coal ◽  
Steam Boiler ◽  
Combustion Technology ◽  
Coal Drying ◽  
Boiler Design ◽  
Gas Recycling

This paper presents the results of a study on modifying a pulverized coal-fired steam boiler in a 250 MWe power plant for oxygen combustion conditions. The entry point of the study is a boiler that was designed for standard air combustion. It has been proven that simply substituting air by oxygen as an oxidizer is not sufficient for maintaining a satisfactory operating mode, not even with flue gas recycling. Boiler design optimization aggregating modifications to the boiler’s dimensions, heating surfaces and recycled flue gas flow rate, and specification of a flue gas recycling extraction point is therefore necessary in order to achieve suitable conditions for oxygen combustion. Attention is given to reducing boiler leakage, to which external pre-combustion coal drying makes a major contribution. The optimization is carried out with regard to an overall power plant conception for which a decrease in efficiency due to CO2 separation is formulated.

scholarly journals Determination of High Temperature Corrosion Rates of Steam Boiler Evaporators Using Continuous Measurements of Flue Gas Composition and Neural Networks

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3134
Author(s):  
Tomasz Hardy ◽  
Sławomir Kakietek ◽  
Krzysztof Halawa ◽  
Krzysztof Mościcki ◽  
Tomasz Janda
Keyword(s):  
Neural Networks ◽  
High Temperature ◽  
Corrosion Rate ◽  
Flue Gas ◽  
Hard Coal ◽  
Steam Boiler ◽  
Gas Composition ◽  
Negative Consequences ◽  
Low Oxygen ◽  
Continuous Measurements

The use of low-emission combustion techniques in pulverized coal-fired (PC) boilers are usually associated with the formation of a reduced-gas atmosphere near evaporator walls. This increases the risk of high temperature (low oxygen) corrosion processes in coal-fired boilers. The identification of the dynamics and the locations of these processes, and minimizing negative consequences are essential for power plant operation. This paper presents the diagnostic system for determining corrosion risks, based on continuous measurements of flue gas composition in the boundary layer of the combustion chamber, and artificial intelligence techniques. Experience from the implementation of these measurements on the OP-230 hard coal-fired boiler, to identify the corrosion hazard of one of the evaporator walls, has been thoroughly described. The results obtained indicate that the continuous controlling of the concentrations of O2 and CO near the water wall, in combination with the use of neural networks, allows for the forecasting of the corrosion rate of the evaporator. The correlation between flue gas composition and corrosion rate has been demonstrated. At the same time, the analysis of the possibilities of significantly simplifying the measurement system by using neural networks was carried out.

Modeling of combustion and hydrodynamics for a coal-fired supercritical boiler with double-reheat cycle

2019 ◽  
Vol 30 (4) ◽  
pp. 1661-1675 ◽  
Author(s):  
Tang Chen ◽  
Wei-zong Wang
Keyword(s):  
Flue Gas ◽  
Heat Exchangers ◽  
Cfd Simulation ◽  
Generation Process ◽  
Steam Generation ◽  
Design Data ◽  
Content Type ◽  
Calculation Results ◽  
Ash Deposit ◽  
Computational Fluid Dynamics Cfd

Purpose The design and retrofit of the heat exchangers in a boiler should take into account the processes occurring on the side of combustion and steam. For this reason, this study aims to couple a one-dimensional hydrodynamic model of steam with computational fluid dynamics (CFD) simulation of flue gas. Design/methodology/approach Radiant/semi-radiant platen heat exchangers are simplified as plane surfaces for CFD, while convective heat exchangers are introduced into the CFD simulation as energy/momentum absorption sources. Findings Numerical simulation is performed for a 1,000 MWe coal-fired ultra-supercritical boiler. The calculation results are validated by the thermodynamic design data. Tube outside surface temperature, as well as ash deposit temperature distributions, are obtained. Originality/value Complex tube arrangements can be completed with the aid of AutoCAD, and therefore, the simulation could offer detailed information of heat exchangers. In a word, a more reliable modeling of the whole steam generation process is achieved.

Three-dimensional CFD simulation of oxy-fuel combustion in a circulating fluidized bed with warm flue gas recycle

Fuel ◽  
2018 ◽  
Vol 216 ◽  
pp. 596-611 ◽  
Author(s):  
Ying Wu ◽  
Daoyin Liu ◽  
Lunbo Duan ◽  
Jiliang Ma ◽  
Jie Xiong ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Flue Gas ◽  
Cfd Simulation ◽  
Circulating Fluidized Bed ◽  
Three Dimensional ◽  
Fuel Combustion
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