【Question 124】Boiler Foundation Questions (July 4)

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This post was last edited by zgj2405 on 2010-7-4 16:27. Please hide your replies; think carefully before posting, as edits are invalid! Those with different views on the provided answer keys can post discussions the next day. For multiple accounts under the same IP responding to participate, only the first response is valid. All participants receive 2 points as a reward. This round consists of multiple-choice questions, with 2 points for each question; an additional 5 points are given for getting all answers correct. Scores are given to the top 30 answerers. 1. The calorific value of standard coal is ( ) kJ/kg. A.20934 B.29310 C.2700 D.12560 When there are fine cracks at the water level in a boiler, the color of the scale on that area should be ( ). A. Dark yellow B. Black C. Red-brown D. White 3. When maintaining a boiler that is not in use using the full-water maintenance method, the water to be poured into the boiler should be ( ). A. Neutral 　　 B. Slightly acidic C. Appropriate alkalinity　　　 D. Ordinary distilled water 4. Soot blowing using soot blowers can also cause tube corrosion or erosion; the reason that is not included among these is ( ). A. Condensate water in the soot-blowing gas B. Excessive frequency of soot-blowing C. Too high airflow velocity D. Cavitation caused by soot-blowing 5. Low-temperature corrosion in boilers usually refers to corrosion that occurs in the ( ) area. A. Near the water inlet              B. Downcomer of the water-tube boiler C. Near the drain outlet              D. Lower flue gas temperature in the heating surface