Heat Exchange Calculation of a Regenerative Air Heater with Numerical Simulation Method

2013 ◽  
Vol 860-863 ◽  
pp. 1416-1419
Author(s):  
Ri Guang Wei ◽  
Zhen Xiao Qu ◽  
Jian Qiang Gao
Keyword(s):  
Numerical Simulation ◽  
Simulation Method ◽  
Calculation Model ◽  
Design Parameters ◽  
Practical Calculation ◽  
Air Preheater ◽  
Air Heater ◽  
Pulverized Coal Boiler ◽  
Set Up ◽  
Coal Boiler

According to the structure and working principle of rotary air preheater,the heat transfer calculation model is set up with reasonable simplification. Combining with the design parameters of the rotary air preheater of a 400 t/h pulverized coal boiler unit ,the results of practical calculation show that the said thermodynamic calculation method not only has higher precision of calculation,but also can get the temperature distributions of the gas, air and heat surface in each cross-section of the rotary air preheater. The result of numerical simulation calculation tallies well with the original designed data. It can be used for the heat calculation both two-sectorial and three-sectorial air heater; it can be used for performance analysis of the regenerative air heater.

scholarly journals Structure parameter optimization and bearing limit analysis of the expansion unit of three-roller tube expander

2020 ◽  
Vol 7 (5) ◽  
pp. 191630
Author(s):  
Gang Bi ◽  
Zhan Qu ◽  
Zhenquan Wang ◽  
Liangbin Dou ◽  
Mengmeng Li
Keyword(s):  
Numerical Simulation ◽  
Simulation Method ◽  
Gauge Length ◽  
Structure Design ◽  
Design Parameters ◽  
Roller Tube ◽  
Unit Structure ◽  
Drilling Technology ◽  
Expansion Force ◽  
Proper Length

The critical technical issues for the structure design of three-roller tube expander were first studied and analysed in this paper. Then, the major design parameters of the expansion unit structure and the bearing limit of 12¼″ three-roller tube expander were optimized and investigated by finite-element numerical simulation method. Results from study show that the required expansion force increases when the taper angle of the roller outer surface gets larger, taking the axial expansion force as the quantitative indicators. It is suggested that the roller tape angle of the expansion unit should be in the range of 9–12° considering the proper length of the roller and the non-self-locking tube expansion process. The required expansion force of the bellows first decreases and then increases when the gauge length of the expansion unit becomes longer. The optimal value of the gauge length is 50 mm considering the proper length of the roller. And according to the numerical simulation results, the designed three-roller tube expander meets the strength requirements. The results of this study are of great significance to the expend bellows drilling technology.

Numerical Simulation on Blasting Fume Diffusion in Blind Roadway with FLUENT

2013 ◽  
Vol 663 ◽  
pp. 655-660
Author(s):  
Zhen Hua Xie ◽  
Zheng Lan Yuan ◽  
Yu Zhang
Keyword(s):  
Numerical Simulation ◽  
Simulation Method ◽  
Mining Area ◽  
Computational Grids ◽  
Actual Situation ◽  
Forced Ventilation ◽  
Iron Mine ◽  
Effective Ventilation ◽  
Set Up ◽  
And Diffusion

Aiming at the generation of blasting fume in underground blind roadway, numerical simulation method was taken to obtain the diffusion law of the blasting fume. In accordance with the actual situation in Shachang mining area of Shouyun iron mine, the physical model and mathematical model were set up, computational grids were divided, and the boundary condition was established. The diffusion law of blasting fume and the completion time under different explosives dosage were simulated by Fluent. The laws of blasting fume diffusion and diffusion time changing with the amount of explosive in local fan forced ventilation were obtained. The results can provide a theoretical basis for the research of a reasonable and effective ventilation manner of blind roadway.

Numerical Simulation of Pyroclastic Flow at Mt. Semeru in 2002

2019 ◽  
Vol 14 (1) ◽  
pp. 116-125
Author(s):  
Makoto Shimomura ◽  
Wilfridus F. S. Banggur ◽  
Agoes Loeqman ◽  
◽  
Keyword(s):  
Numerical Simulation ◽  
Friction Factor ◽  
Pyroclastic Flow ◽  
Sudden Change ◽  
Simulation Method ◽  
Active Volcano ◽  
Flow Path ◽  
Pyroclastic Flows ◽  
Set Up ◽  
The Individual

Mt. Semeru (3676 m asl.) is an active volcano in Indonesia. Mt. Semeru has a specific topography i.e., a large straight scar in its south-east flank. The geometry of the scar is approx. 2 km in length and 300–500 m width. The scar is connected to three major drainage channels: the Kobokan River, the Kembar River, and the Bang River. On December 29, 2002, a pyroclastic flow (PF) with an approximate volume of 3.25 × 106m3was generated and it traveled 9–11 km along the Bang River. This pyroclastic flow was the largest among the ones generated from 2002–2003 eruptions of Mt. Semeru. All prior recorded pyroclastic flows traveled 1–2.5 km along the Kembar channel. Thus, this pyroclastic flow suddenly changed its flow path, and it traveled more than three times longer than its antecedents. To investigate the cause of the sudden change, a simulated reproduction of this pyroclastic flow was carried out by employing the numerical simulation method proposed by Yamashita and Miyamoto (1993). Due to the uncertainty of the volume of each pyroclastic flow and the temporal change of deposition thickness, a total of 12 simulation cases were set up, with variations in the number of sequence events, the duration of inflow at the upper reach of the flow, and the inter-granular friction factor. The simulation results showed that to explain the sudden change in flow path, the Kembar channel, around 3 km from the vent, has to be buried by antecedent pyroclastic flows. Furthermore, the individual volumes of the prior flows must be less than 0.25–1× 106m3, with an inflow duration of less than 1 min. The friction factor must be set to be 0.5. By using the most acceptable case, the simulated pyroclastic flows were in good agreement with observed results. The results implied that careful investigation and continuous monitoring of the area at 1500–2000 m asl. on the south-east flank of Mt. Semeru are important to prepare for future pyroclastic flows.

Numerical Simulation of O2/CO2 Pulverized Coal in 300MW Boiler

2013 ◽  
Vol 732-733 ◽  
pp. 133-137
Author(s):  
Li Li Li ◽  
Chao Qu
Keyword(s):  
Numerical Simulation ◽  
Flue Gas ◽  
Volume Fraction ◽  
Simulation Software ◽  
Pulverized Coal ◽  
Central Position ◽  
Pulverized Coal Boiler ◽  
Combustion Technology ◽  
Secondary Air ◽  
Coal Boiler

O2/CO2combustion technology is an effective method to capture and store coal-fired boiler flue gas CO2. With a 300MW subcritical pulverized coal boiler as the research subject investigated, Fluent numerical simulation software is used to simulate the process of pulverized coal combustion both in air and O2/CO2conditions. The comparative analyses are made both in the former conditions, such as the combustion characteristics of pulverized coal, the influence of oxygen volume fraction, the effect of the secondary air temperature on the temperature field in the furnace of pulverized coal boiler. As for the following results of the pulverized coal combusted in the O2/CO2condition, compared with the results in the air condition, its time of ignition is delayed, and the combustion temperature is low and the central position of flame rises. With the increasing percentage of the oxygen volume and the rising temperature of secondary air, the time of ignition speeds up, which improves the overall furnace temperature level and transferring capability of the radiation heat.

Flow Characteristic of a New Type of Double-Channel Air Burner in Direct Flow Pulverized Coal Boiler

2012 ◽  
Vol 614-615 ◽  
pp. 59-63
Author(s):  
Jian Guo Yang ◽  
Hai Ming Yu ◽  
Li An Fan ◽  
Hong Zhao
Keyword(s):  
Simulation Method ◽  
Pulverized Coal ◽  
Existing Problems ◽  
Pulverized Coal Boiler ◽  
Flow Adjustment ◽  
Coal Powder ◽  
Low Nox Combustion ◽  
New Type ◽  
Coal Boiler ◽  
Double Channel

Tangentially-fired burner is widely used in pulverized coal boiler, but its air burner has some shortcomings, including the velocity of exit airflow weaken with the decrease of the opening degree of the air damper, leading to insufficient mixing between air and coal-powder. In view of the existing problems, a new type of double-channel air burner had been designed. Its flow field and adjustment characteristic were studied by using numerical simulation method. The results showed the double-channel air burner had effective flow adjustment characteristic which closely linearity. One of the channels could keep higher exit velocity when the air volume decrease and it could fulfill the demand of air adjustment better while in low NOx combustion or load variation.

scholarly journals Study on Numerical Simulation of Fire Danger Area Division in Mine Roadway

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Hu Wen ◽  
Yin Liu ◽  
Jun Guo ◽  
Ze Zhang ◽  
Mingyang Liu ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
High Temperature ◽  
Gas Flow ◽  
Concentration Field ◽  
Environmental Parameters ◽  
Simulation Method ◽  
Development Stage ◽  
Calculation Model ◽  
Mine Fire ◽  
Mine Roadway

High-temperature poisonous smoke produced by coal mine roadway fire seriously affects miners' lives and safety. Studying the development law of high-temperature smoke in the process of mine roadway fire and then exploring the danger of roadway are of great significance to personnel safety and post-disaster rescue. In order to study this problem, the CFD numerical simulation method is used to establish a fire calculation model based on ANSYS Fluent software in the development stage of mine fire. The high-temperature flue gas flow in the roadway during the development stage of mine fire is simulated, and the variation law of temperature field and gas concentration field with time and space position under different levels of roadway in the development stage of fire is revealed. The variation rules of environmental parameters, such as temperature, CO, and CO2, are obtained by numerical calculation. Based on these, the danger zones of smoke spread in fire development stage are divided by the critical values of high-temperature smoke and toxicity evaluation index, and the mathematical fitting analysis of the evolution of the dangerous area with time is carried out. The research results have certain theoretical guiding significance for reducing underground environmental pollution and ensuring the personal safety of workers and rescuers.

Reliability Simulation of Mining System for Mechanized Coal Face

2010 ◽  
Vol 33 ◽  
pp. 695-699
Author(s):  
Chun You Dong ◽  
Dao Hua Pan ◽  
Jian Ting Shi ◽  
Xue Liu
Keyword(s):  
Simulation Method ◽  
System Optimization ◽  
Calculation Model ◽  
Actual Condition ◽  
Coal Face ◽  
Mining System ◽  
Model And Simulation ◽  
Service Distribution ◽  
Normal Production ◽  
Set Up

This paper first analyzes the logical relationship in mining system of fully mechanized coal face and then establishes the system reliability calculation model and simulation model. Based on the running technological data from the mechanized coal face, the authors obtain normal production service distribution and set up equation of monthly output and availability, with which the production and availability are simulated. The test of simulation results on actual condition shows that the simulation method is reliable. This approach contributes to performance evaluation on fully mechanized coal face, improvement on mining system, optimization of mining parameters, equipment modeling and matching. It can also be extended to reliability analysis of other systems.

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