Stack temperature is the temperature of the combustion gases (dry and water vapor) leaving the boiler. A well-designed boiler removes as much heat as possible from the combustion gases. Thus, lower stack temperature represents more effective heat transfer and lower heat loss up the stack. The stack temperature reflects the energy that did not transfer from the fuel to steam or hot water. Stack temperature is a visible indicator of boiler efficiency. Any time efficiency is guaranteed, predicted stack temperatures should be verified.
Stack loss is a measure of the amount of heat carried away by dry flue gases (unused heat) and the moisture loss (product of combustion), based on the fuel analysis of the specific fuel being used, moisture in the combustion air, etc.
1. They are all a heat conversion device. The heat transfer medium they use is different. The water used in the steam boiler is heated to become steam. The heat transfer medium of thermal oil heater is heat medium oil. The heat is transferred to the heated substance by the heat medium oil.2. When a higher heating temperature is required, such as 280 degrees, the steam pressure of the steam boiler should reach 7MPa or more, and the process piping and heat exchange equipment must also withstand the same pressure. The equipment cost is high and dangerous. Thermal oil heater provides a temperature above 280 degrees, but the pressure is lower than 1MPa.3. The temperature of thermal oil heater can be accurately controlled within 3 degrees and the temperature of the steam changes greatly.4. Thermal oil heater is used alone, the exhaust gas temperature is higher, and the thermal efficiency is lower than that of the steam boiler. However, if used in conjunction with a steam boiler, the
Question details (Performance):Dust collecting cloth bag damages a lot. Answer: The cause of the problem: As the biomass-fired boiler fuel moisture is high, and bag material is general PPS, which will reduce the base fabric of the bag in the case of high temperature, high humidity, hydrolysis, oxidation, and cause damage; In addition, the fuel moisture is high and it cannot be completely burned in the furnace, so it burns in the dust collector, which is also an important reason for the damage of the cloth bag.Troubleshooting:(1) Design by full consideration of high fuel moisture, choosing the appropriate induced draft fan, if the existing design is not enough then consider change the induced draft fan.(2) If induced air volume is sufficient, a proper distribution of the first and second wind should be considered. Generally, the fuel with high moisture and light quality such as wood chips, straw and wheat straw hood, the secondary air volume should be increased. For bark, miscellaneous
(Details on the problem) Specific Performance:Slagging pipe blocks during operation of circulating fluidized bed boiler. Answer：cause of failure:(1) The internal shape is caused by the limited expansion of the wear-resistant material inside the slag discharge pipe. The internal components of the slag cooler are deformed, affecting the fluidization of the slag cooler; the slag cooler is deactivated for a long time or a single slag cooler is selected for slagging, and the bed material in the deactivated slag cooler is bonded under the influence of steam, which being low temperature coke.(2) The operating personnel did not grasp the ratio of the fluidized air volume of the slag cooler. Inappropriate air volume ratio resulted in poor ash slag fluidization in the slag cooler. Troubleshooting:(1) Operation personnel should strengthen understanding of boiler operating conditions, adjust boiler parameters in a timely manner, set up the concept of boiler material dynamic balance, control boiler
