In this paper, a method and algorithm of skeleton extraction based on binary mathematical morphology is presented. Sequential structuring elements (SEs) is also studied, which is the key problem of skeleton extraction...In this paper, a method and algorithm of skeleton extraction based on binary mathematical morphology is presented. Sequential structuring elements (SEs) is also studied, which is the key problem of skeleton extraction. The examples of boiler flame image processing show that the detected skeletons can present the geometric shape of flame images well.展开更多
Ni-Cr based nanostructured feedstock powder was prepared by mechanical milling technique involving repeated welding, fracturing, and re-welding of powder particles in a planetary ball mill. The milled nanocrystalline ...Ni-Cr based nanostructured feedstock powder was prepared by mechanical milling technique involving repeated welding, fracturing, and re-welding of powder particles in a planetary ball mill. The milled nanocrystalline powders were used to coat carbon steel tubes using high velocity oxygen fuel（HVOF） thermal spraying process. The characterization of the feedstock powder and HVOF coated substrates was performed using optical microscope, X-ray diffractometer（XRD）, scanning electron microscope（SEM）, high resolution transmission electron microscope（HR-TEM）, energy dispersive spectrometer（EDS） and microhardness tests. The coated and uncoated samples were subjected to different thermal cycles and characterized for their phase changes, metallurgical changes and microhardness variations. Ni-Cr nanostructured coated samples exhibited higher mechanical and metallurgical properties compared to their conventionally coated counter parts. The results showed that the nanostructured coating possessed a more uniform and denser microstructure than the conventional coating.展开更多
The combustion condition in coal-fired furnaces of the large power station boiler is very complex and the flame emissivity is one of the important combustion parameters. A measurement method of the flame emissivity ba...The combustion condition in coal-fired furnaces of the large power station boiler is very complex and the flame emissivity is one of the important combustion parameters. A measurement method of the flame emissivity based on the blackbody furnace calibration of CCD （Charge Coupled Device） cameras and the color image processing techniques of computer was introduced. The experimental research on the flame emissivity in a 200 MW boiler furnace and a 300 MW boiler furnace was conducted respectively through the several CCD cameras installed at different height in furnace. The measurement results show： the flame emissivity increases with the increase of the unit load, the flame emissivity of the burner areas in furnace is the highest and the flame emissivity decrease with the increase of height of furnace above the burners area.展开更多
Based on reason analyses for frequent flameout of HG-1025/18.2-YM6 boiler in a given power plant after coal quality variation, major factors such as unreasonable burner structure and inappropriate secondary air distri...Based on reason analyses for frequent flameout of HG-1025/18.2-YM6 boiler in a given power plant after coal quality variation, major factors such as unreasonable burner structure and inappropriate secondary air distribution were discussed in detail. A new mode of secondary air distribution was introduced to optimize the combustion performance, and a lower burner was retrofitted by increasing the relative distance between the primary air fuel rich-lean nozzles and reducing the size of waist air nozzles as well. As a result, the recirculating zone became more stable and the burner's combustion stability was improved.Practical operation shows that the modifications are so effective that the flameout problems caused by instable combustion never occur in operation.展开更多
In this paper,the designed features of a W-flame coal-fired boiler are introduced.A scheme of joint primary air for two boilers is made and technical measures are also taken based on corresponding analyses and studies...In this paper,the designed features of a W-flame coal-fired boiler are introduced.A scheme of joint primary air for two boilers is made and technical measures are also taken based on corresponding analyses and studies.The scheme and the measures provide a reference for technicians to improve the efficiencies and reduce the startup costs of other similar large boilers.展开更多
In this paper, the effect of the imaginary circle diameter opi and the initial flow field on the aerodynamic field in a tangentially fired furnace was studied by numerical simulation and experiments in the cold model....In this paper, the effect of the imaginary circle diameter opi and the initial flow field on the aerodynamic field in a tangentially fired furnace was studied by numerical simulation and experiments in the cold model. Results show that merely reducing the imaginary circle diameter rki can not significantly reduce the rotatiollal diameter op in the range considered. The flow still rotates coullter-clockwise stably and does not change rotation direction when the direction of all jet axes are defiected suddenly to the opposite rotation direction by up to 5.4" in a countereclockwise llow field. It is the first time that the numerical sAnulation results were obtained which agreed quite well with this experimental phenomena qualitatively. The experimental data, i.e., the rotational diameter & and the maximum velocity on the syrnmetric central line of fUrnace Vm, are only a bit larger than the simulation results. It is shown that the initial flow field has an important influence on the aerodynamic field in the furnace. Other measures have to be taken as wel1 in order to reduce & to resist slagging and high temperature corrosion of furnace tubes. Moreover, a new kind of grid arrangement was proposed in this paper, which can reduce effectively the false diffosion at the exit zone of burner.展开更多
文摘In this paper, a method and algorithm of skeleton extraction based on binary mathematical morphology is presented. Sequential structuring elements (SEs) is also studied, which is the key problem of skeleton extraction. The examples of boiler flame image processing show that the detected skeletons can present the geometric shape of flame images well.
基金supported and funded from consultancy project of Bharath Heavy Electricals Limited, Tiruchirappalli,India
文摘Ni-Cr based nanostructured feedstock powder was prepared by mechanical milling technique involving repeated welding, fracturing, and re-welding of powder particles in a planetary ball mill. The milled nanocrystalline powders were used to coat carbon steel tubes using high velocity oxygen fuel（HVOF） thermal spraying process. The characterization of the feedstock powder and HVOF coated substrates was performed using optical microscope, X-ray diffractometer（XRD）, scanning electron microscope（SEM）, high resolution transmission electron microscope（HR-TEM）, energy dispersive spectrometer（EDS） and microhardness tests. The coated and uncoated samples were subjected to different thermal cycles and characterized for their phase changes, metallurgical changes and microhardness variations. Ni-Cr nanostructured coated samples exhibited higher mechanical and metallurgical properties compared to their conventionally coated counter parts. The results showed that the nanostructured coating possessed a more uniform and denser microstructure than the conventional coating.
文摘The combustion condition in coal-fired furnaces of the large power station boiler is very complex and the flame emissivity is one of the important combustion parameters. A measurement method of the flame emissivity based on the blackbody furnace calibration of CCD （Charge Coupled Device） cameras and the color image processing techniques of computer was introduced. The experimental research on the flame emissivity in a 200 MW boiler furnace and a 300 MW boiler furnace was conducted respectively through the several CCD cameras installed at different height in furnace. The measurement results show： the flame emissivity increases with the increase of the unit load, the flame emissivity of the burner areas in furnace is the highest and the flame emissivity decrease with the increase of height of furnace above the burners area.
文摘Based on reason analyses for frequent flameout of HG-1025/18.2-YM6 boiler in a given power plant after coal quality variation, major factors such as unreasonable burner structure and inappropriate secondary air distribution were discussed in detail. A new mode of secondary air distribution was introduced to optimize the combustion performance, and a lower burner was retrofitted by increasing the relative distance between the primary air fuel rich-lean nozzles and reducing the size of waist air nozzles as well. As a result, the recirculating zone became more stable and the burner's combustion stability was improved.Practical operation shows that the modifications are so effective that the flameout problems caused by instable combustion never occur in operation.
文摘In this paper,the designed features of a W-flame coal-fired boiler are introduced.A scheme of joint primary air for two boilers is made and technical measures are also taken based on corresponding analyses and studies.The scheme and the measures provide a reference for technicians to improve the efficiencies and reduce the startup costs of other similar large boilers.
文摘In this paper, the effect of the imaginary circle diameter opi and the initial flow field on the aerodynamic field in a tangentially fired furnace was studied by numerical simulation and experiments in the cold model. Results show that merely reducing the imaginary circle diameter rki can not significantly reduce the rotatiollal diameter op in the range considered. The flow still rotates coullter-clockwise stably and does not change rotation direction when the direction of all jet axes are defiected suddenly to the opposite rotation direction by up to 5.4" in a countereclockwise llow field. It is the first time that the numerical sAnulation results were obtained which agreed quite well with this experimental phenomena qualitatively. The experimental data, i.e., the rotational diameter & and the maximum velocity on the syrnmetric central line of fUrnace Vm, are only a bit larger than the simulation results. It is shown that the initial flow field has an important influence on the aerodynamic field in the furnace. Other measures have to be taken as wel1 in order to reduce & to resist slagging and high temperature corrosion of furnace tubes. Moreover, a new kind of grid arrangement was proposed in this paper, which can reduce effectively the false diffosion at the exit zone of burner.
