The heat loss of exhaust smoke is the largest of all kinds of heat loss in boiler. Generally, the heat loss of exhaust smoke is 6% of the heat fed into the furnace, and the heat loss of exhaust gas increases 0.5% when the temperature of exhaust gas increases by 12 ℃ and 15 ℃. So the exhaust temperature is one of the most important indicators of boiler operation. The following are several possible causes of increased flue gas temperature in the furnace: (1) slagging and ash accumulation on the heated surface. No matter it is the slag accumulation in the water-cooled wall of the furnace, or the ash deposition in the superheater, convection tube bundle, economizer and preheater, the thermal resistance of the flue gas measurement will increase, the cooling effect of the flue gas will become worse due to the deterioration of the heat transfer, and the exhaust temperature will rise. (2) excess air coefficient Big. Under normal conditions, the exhaust temperature increases with the increase of excess air coefficient at furnace outlet. After the increase of excess air coefficient, although the amount of smoke increased, the rate of smoke increased, and the convection heat increased, the increase of heat transfer was not as much as that of the increase of flue gas. It can be understood that after the increase of smoke speed, the flue gas leaves the heating surface without time to transfer heat to the working fluid. (3) the air leakage coefficient is too large. The flue gas leakage in the furnace and rear shaft of a negative pressure boiler is inevitable and the leakage coefficient allowed by a certain heating surface is specified. When the air leakage coefficient increases, the effect on the exhaust temperature is similar to that of the superheated air coefficient. And the air leaks away. The closer the furnace is, the greater the influence on the rise in exhaust temperature. (4) Water supply temperature. When the steam turbine load is too low or the high pressure heater is out of line, the feed water temperature of the boiler will be lowered. Generally speaking, if the fuel quantity is kept constant, the heat transfer temperature difference of the economizer decreases and the heat absorption of the economizer decreases when the feed water temperature is increased, which makes the exhaust temperature increase. (5) moisture in the fuel. The increase of moisture in the fuel increases the amount of smoke, thus increasing the exhaust temperature. (6) Boiler load. Although the boiler load increases proportionally, the amount of smoke, the amount of steam, the amount of water supplied, and the volume of air increase proportionally, however, the flue gas temperature at the furnace outlet increases proportionally. Increase, so that the exhaust temperature increased. After increasing the load, the outlet temperature of the furnace increases, the heat transfer temperature difference of the convection heating surface increases and the heat absorption increases. Therefore, the more the convection heating surface is, the less the influence of the boiler load on the exhaust gas temperature is. (7) fuel varieties. When the low calorific value gas is fired, the radiative heat transfer in the furnace decreases due to the decrease of furnace temperature, and the non-combustible components in low calorific value gas, mainly N _ 2, CO _ 2 and H _ 2O, increase the amount of flue gas, so the exhaust temperature increases. Although the excess air coefficient of furnace outlet is lower than that of coal burning, the ash content in the fuel oil is very low after the pulverized coal furnace is changed to burn oil, although the excess air coefficient at the furnace outlet is lower when burning oil. There is no larger ash particle in flue gas, and there is no cleaning effect of larger ash particle on the heating surface, and the convection heating surface is polluted more seriously. Therefore, combustion is not good, often smoke-emitting boiler smoke temperature rise. When there is a steel ball dust removal device at the tail, the exhaust temperature is slightly lower than that of burning coal because the tail is cleaner. (8) the operation mode of pulverizing system. For a closed pulverizing system with a silo, when the pulverizing system is in operation, as a part of the water in the fuel enters the furnace, the furnace temperature decreases and the flue gas increases, and the cold air leaking into the pulverizing system enters the furnace as a primary air during the operation of the pulverizing system. Reduction of air flow through air preheater To raise the exhaust temperature. On the contrary, when the pulverizing system is shut down, the exhaust temperature decreases.
Steam boiler wear and electric test pump DSY Henan fast boiler's 15000kg coal fired steam boiler small series with you about wear and DSY electric test pump wear is one common steam boiler heating surface defects, boiler heating surface is arranged in the boiler the furnace and the flue, in particular a heating surface in the steam boiler flue vertical tail, by the long brush smoke, soot in the flue gas so that the wall heating surface wear thinned, so that heat from the flue gas scouring wall ironed a phenomenon known as wear and tear. Flow rate, the concentration of soot in the flue gas and the hardness of the tube bundle arrangement such factors as the wear rate of the heating surface of the steam boiler and the flue gas is related to the flow rate of flue gas wherein the greatest impact on the wear of the heating surface. Experimentally measured, proportional to the cube of the wear rate of the heating surface tubes and the flue gas velocity, it is necessary to effectively control the flow rate of flue gas. Leakage of the furnace wall, a partial wall flue ash, convection heating surface partially severe slagging will cause a partial flue gas velocity is too large, so that the heating surface tubes local wear increased, further, when the soot blowers work failure, high pressure steam steam heating surface tube will blow erosion, so that the wall thinning. Heating surface tubes often wear area is: cool ash, burner, bullnose, and close to Manhole sootblowing waterwall tube aperture; a lower portion of the flue gas before the steering tube heating surface vertical chamber; vertical tail horizontal heating surface portion of the second row of three tubes of the flue, the lower portion of the second three tubes, tube support edge portion of the clip, close to the furnace wall side of the rows of tubes and the individual tubes and the like projecting tube rows. Heating surface wear reduction methods are: to reduce boiler load, reducing flue gas velocity; burning coal quality, reducing the content of fly ash in the boiler flue gas steam; change bundle arrangement, a staggered arrangement to the line arrangement; Clear slagging and blocking flue ash, flue gas flow area increases; leakage reduction furnace wall; the installation of a shoe or the spoiler like. Abrasion test on the electric pump plunger hole set DSY electric test checking pump plunger sleeve (1) Check the DSY type. If the pump DSY electric test has passed the test on sealing ST-990 or the tester 3,375,375, the plunger sleeve is available. If the leakage is large, it is necessary to replace the plunger and plunger sleeve. (2) using the burr, coke, and high-expansion magnifying glass to check the amount of deformation of the bore. When the metering orifice is damaged, DSY i.e. electric test pump is not working properly. Do not attempt to clean with a wire, plug, etc., should be cleaned with a solvent. (3) Check the fuel oil channel as well as choking loose plunger sleeve for cracks. (4) Check DSY electric test pump plunger sleeve surface endless belt black area and Degree how damage flatness. Some electric test pump head end of the barrel nozzle sump has been canceled. Henan is committed to fast boiler steam boiler manufacturing, product quality, reasonable prices and widespread industry praise, if you have any needs, please contact us!
A number of national influence energy consumption 15000kg coal fired steam boiler coal to natural gas has been vigorous work, it should be transported steam boiler, very big eliminate the dust pollution, discharge of toxic gases and secondly nitric oxide, also got curb. Energy consumption is crucial mark measuring steam boiler, a good start and that is that work together to explore under the influence of a number of cases the energy consumption of steam boilers. Through the investigation of the persons concerned, the loss of heat from steam boilers bear the main two areas: combustion air-fuel ratio does not smoke emissions standards-related heat loss. Reduction of heat loss will install smoke emission in the flue gas heat recovery steam boiler terminal fitting, or should be transported more leading type condensation recovery boiler. Combustion air-fuel ratio standard fault summary: a conventional steam boiler burner ejector type, formed air-fuel ratio can not occur motorized adjustment. Some of the steam boiler with a mechanical blower burner, causing air-fuel ratio standard there are several aspects later: the main air-fuel ratio standard case encompass fall into two categories: air flow when exceeded, there will be an endless excess cold heat transfer, resulting in high energy cost of steam boilers, steam boilers reduced energy consumption; when the airflow is not enough, will have not exactly lit, the energy consumption caused by steam boiler weakened.
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