Coal big card measurement of fuel calorific value in the determination of problems - Database & Sql Blog Articles

Detecting the large card of coal, the calorific value of the big card test , the problems that may be encountered in the measurement of coal big cards, Yinghua Xiaobian help you summarize: First, determine the gray matter to pay attention to those matters? Answer: 1. The high temperature furnace is well ventilated, and the chimney should be installed correctly. 2. The position of the thermocouple should be correct. 3. The position of the ash dish in the furnace should be suitable. 4. The ash dish should be placed in the constant temperature area. 5. The coal sample should be completely ashed. The cooling time in the air should be consistent. Second, why should we call the volatile yield and not the volatile content? A: The meaning of the two is different. The volatile content is often understood as a component of the original coal. It is inherent, but in fact it is the product of thermal decomposition of coal under certain conditions. Different temperatures have different volatile yields, and their chemical compositions are also different. Therefore, the determination result of volatiles should not be called volatile content, and the yield of volatiles is more accurate. 3. What is the significance of measuring calorific value for electricity production? Answer: 1. It is based on calorific value in terms of coal quality pricing, compilation of consumption quota and supply plan, accounting of power generation cost and calculation of energy utilization efficiency. 2. Designing boilers, designing furnace load, and selecting coal. Machine capacity and important parameters for calculating material balance 3 are the main basis for boiler heat balance, coal blending combustion and load regulation, and at the same time one of the basis for calculating coal consumption. 4. What conditions should the room for measuring heat should have? Answer: 1. Should be in a single room 2. The indoor temperature should be as constant as possible. 3. There should be no strong air convection and heat source in the room. 5. What is the heat of the cartridge? A: The unit mass of fuel (except the gaseous state) is completely burned in the oxygen bomb filled with oxygen (the final state of the combustion product is 25 ° C). This is the amount of heat released for the barrel. Sixth, what is the high heat? A: The calorific value of the barrel is subtracted from the heat generated by the formation of heat and the difference between the heat of sulfuric acid and sulfur dioxide. Seven, what is the low heat? A: The heat generated by the high heat loss minus the heat of vaporization of water (water produced by hydrogen combustion in coal and water in coal). 8. Why is it required to do a water pressure test of not less than 20MPA per year for oxygen bombs? Answer: 1. The fuel burns violently in the oxygen bomb and rapidly generates heat, so that the pressure inside the oxygen bomb rises rapidly. 2. For the long-term use of oxygen bombs, the threads of the projectile and the connecting ring are often corroded or Wear and increase the degree of looseness, thereby reducing the pressure resistance. 9. Why is benzoic acid selected for the calibration of heat capacity? Answer: 1. The extraction method is simple, easy to obtain stable crystal structure, high purity and stability; 2. Low moisture absorption performance; 3. Low volatility at normal temperature; 4. The calorific value of the complete combustion is close to the calorific value of the fuel to be tested. X. What is the internal moisture of coal? Answer: It refers to adsorption or coagulation in the capillary pores inside the coal particles. In actual measurement, it refers to the part of water that is retained when the coal sample reaches the air dry state. XI. What is the external moisture of coal? Answer: The moisture adsorbed on the surface of coal particles or in non-capillary pores refers to the water lost when the coal sample reaches the air dry state. 12. How should the volatiles be measured to get the correct results? Answer: 1. Before weighing, the crucible should be burned to constant weight at 900±10°C. The mass of the sample weighed should be within the range of 1±0.01g, and the sample should be flattened. There are enough constant temperature zones 4, 坩埚 to meet the requirements 5. When measuring, pay attention to observe that the furnace temperature should be restored to 900±10 °C within 3 minutes. The thermocouple should be installed correctly and periodically verified. 7. The furnace should be sealed. The truss should meet the requirements. 13. What are the components of the oxygen bomb calorimeter? A: oxygen bomb, inner cylinder, outer cylinder, agitator, calorimeter thermometer. 14. What changes will occur in coal placed for a long time? Answer: 1. The calorific value is reduced, the volatile content is changed, the ash yield is increased by 4, the element composition is changed, and the crushing strength is lowered. 15. What equipment should I usually have in the sample preparation room? A: 1, crushing equipment 2, shrinking equipment 3, screening equipment 4, as well as manual grinding of coal-like steel plates, steel rolls, cross-shaped plates, flat plates, shovel and so on. 16. What is the effect of volatiles on boiler combustion? Answer: 1. The coal with high volatile content is easy to catch fire, the flame is large, the combustion is stable, but the flame temperature is low; 2. The coal with low volatile content is not easy to ignite, the combustion is unstable, and the chemical and mechanical incomplete combustion loss increases seriously. Causes a flameout. 17. How to fix a valid number? A: Four rounds and six rounds into five pairs: 1. The first digit of the proposed discarding value is greater than 5 and then enters 1; 2. The first digit of the proposed discarding value is equal to 5, and the number after the 5 is not all ○, then 1 3, the first digit of the value to be discarded is equal to 5, and the number after 5 is all 0. If 5 is odd in front, then 1 is doubled, and if 5 is even, it is discarded. Original link: http://