2011 Boiler Inspector Examination Questions and**

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ID number: Examination number: Name: Sealing line Test paper for the re-examination of the qualifications of boiler inspectors in 2011 Score: Question type Points Possible Deductions Signature of the grader True/False questions 20 points Multiple-choice questions 20 points Short-answer questions 20 points Comprehensive application questions 40 points Total score 100 points National Qualification Assessment Committee for Special Equipment Inspectors March 28, 2011 I. True/False questions (Mark √ for correct statements and × for incorrect ones within the parentheses. There are 20 questions in total, 1 point for each question, for a total of 20 points. 1. The special equipment referred to in the Regulations on the Safety Supervision of Special Equipment includes boilers, pressure vessels (including gas cylinders), and pressure pipelines that are related to life safety and pose high risks. ( × ) 2. The Regulations on the Safety Supervision of Special Equipment stipulate that the inspection and testing activities carried out by institutions specialized in the inspection of special equipment must comply with the requirements of safety technical specifications. ( √ ) 3. The Regulations on the Safety Supervision of Special Equipment stipulate that units engaged in boiler cleaning shall carry out such cleaning in accordance with the requirements of safety technical specifications, and shall also undergo supervision and inspection of the boiler cleaning process by specialized agencies for inspection and testing of special equipment. ( √ ) 4. In accordance with the Provisions on the Safety Supervision of Special Equipment, special equipment must go through registration procedures before it can be put into use. ( × ) 5. In accordance with the provisions of the \"Safety Technical Inspection Regulations for Steam Boilers,\" for shell-type boilers that use expansion joints, the ends of the smoke tubes that are in direct contact with the flame (with a smoke temperature of over 800°C) must have their edges bent at 90°. ( √ ) 6. The Regulations on Safety Technical Inspection of Steam Boilers stipulate that any substitution of materials for the pressure-bearing components of a boiler must be approved by the original design unit, and the change must be recorded with the entity responsible for reviewing the designs. ( × ) 7. TSG G0002-2010 \"Regulations on the Supervision and Management of Energy-Saving Technologies for Boilers\" specifies the basic requirements regarding energy saving in boilers and their systems. ( √ ) 8. In accordance with the provisions of TSG G0002-2010 \"Regulations on the Technical Supervision and Management of Boiler Energy Efficiency\", steam boilers with a rated evaporation capacity of 4 t/h shall be equipped with steam flow meters. ( × ) 9. The TSG G3002-2004 \"Rules for Supervision and Inspection of Boiler Installation\" classifies the methods for verifying boiler installation supervision into three types: document verification, on-site supervision, and physical inspection. ( √ ) 10. Cracks that occur in the pressure-bearing components of industrial boilers due to fatigue must be repaired by welding only after stress relief has been carried out. (×) 11. TSG G0003-2010 “Rules for Energy Efficiency Testing and Evaluation of Industrial Boilers” stipulates that the thermal efficiency testing of standardized boiler products can only be conducted at the manufacturer’s premises. ( × ) 12. In accordance with the provisions of TSG G0003-2010 \"Rules for Energy Efficiency Testing and Evaluation of Industrial Boilers\", when conducting a simple test of the thermal efficiency under normal operating conditions of the boiler, it is not necessary to carry out industrial analysis of the fuel. ( × ) 13. In accordance with the provisions of TSG G0003-2010 \"Rules for Energy Efficiency Testing and Evaluation of Industrial Boilers\", for boilers with a rated evaporation capacity (rated thermal power) of 20 t/h (14 MW) or more, the reverse balance method may be used for energy efficiency testing. ( √ ) 14. The heat loss due to incomplete combustion of solids is the main factor affecting the thermal efficiency of boilers. ( × ) 15. Creep is one of the common failure modes of economizer tubes. ( × ) 16. Pipelines within the boiler area generally refer to the steam and water pipes in the boiler room, but do not include the steam distribution cylinders. ( × ) 17. Q245R steel plates and Q345R steel plates can be used in both pressure vessel manufacturing and boiler manufacturing. ( √ ) 18. Endoscopy is commonly used to check for defects such as cracks and corrosion inside the shell of a surface-type desuperheater. ( × ) 19. The Rules for Periodic Inspection of Boilers stipulate that for power station boilers that have reached 100,000 hours of operation, hardness, creep cracking, and metallographic inspections should be carried out on the curved sections of the feedwater pipes. ( × ) 20. According to GB/T9222-2008 \"Calculation of Strength for Pressured Components in Water Tubular Boilers\", the calculated wall temperature of a pressured component is taken as the arithmetic average of the inner and outer wall temperatures of that component. ( × ) II. Multiple-choice questions (Please fill in the correct **code in the blank.) There are 20 questions in total, 1 point for each question, for a total of 20 points. 1. According to the Regulations on the Safety Supervision of Special Equipment, if special equipment does not meet the energy efficiency standards, the user unit shall… a. It is prohibited to use it. b. Appropriate measures should be taken for rectification. c. It should be reported to the quality and technical supervision department. d. Rectification should be carried out during the major overhaul of the boiler. **: b 2. In accordance with the provisions of the Regulations on the Safety Supervision of Special Equipment, special equipment inspection and testing institutions bear legal responsibility for their . a. Inspection and testing results b. Inspection and testing records c. Inspection and testing reports d. Identification conclusions **: a d 3. The Regulations on the Safety Supervision of Special Equipment stipulate that when special equipment inspection and testing institutions conduct such inspections and tests, if they discover anything, they must promptly inform the units that use the special equipment, and at the same time report to the authorities responsible for the safety supervision of special equipment. a. Serious potential accident hazards b. Severe violations of regulations c. Excessive energy consumption d. Severe waste **: a c 4. The Regulations on the Safety Supervision of Special Equipment stipulate that units responsible for the manufacturing, installation, and modification of boilers, pressure vessels and their safety accessories and protective devices, as well as units responsible for the manufacturing of pressure pipeline components, must obtain permission before engaging in such activities. a. The State Council’s department responsible for the safety supervision and management of special equipment
b. The departments responsible for the safety supervision and management of special equipment in provinces, autonomous regions, and municipalities directly under the Central Government
c. The State Council’s department responsible for the safety supervision and management of special equipment or the departments responsible for such supervision and management at the provincial, autonomous region, or municipal level
**: a
5. In accordance with the Regulations on the Safety Supervision of Special Equipment, the departments responsible for the safety supervision and management of special equipment in provinces, autonomous regions, and municipalities directly under the Central Government shall, together with relevant authorities, organize an accident investigation team to conduct the investigation. a. Extraordinarily serious accident b. Serious accident c. Relatively serious accident d. Ordinary accident **: c 6. Appendix I of the \"Safety Technical Inspection Regulations for Steam Boilers\" stipulates that the welding procedure qualification test pieces must be welded by the welders from the same unit. a. Welders who have passed the examination b. Skilled welders c. Experienced welders **: b 7. There is a safety valve installed on each of the three components – the boiler drum, the superheater, and the economizer. The highest set pressure among them is , and the lowest is . a. Drum safety valve b. Superheater safety valve c. Economizer safety valve **: c b 8. According to the \"Safety Technical Inspection Regulations for Hot Water Boilers,\" the heating surfaces of all parts of steel boilers must be properly cooled to prevent vaporization; the outer diameter of the heating surface tubes inside the furnace should be greater than . a. 25mm b. 32mm c. 38mm d. 50mm **: c 9. In accordance with the provisions of TSG G0002-2010 \"Regulations on the Supervision and Management of Boiler Energy-Saving Technologies\", for steam boilers with a rated evaporation capacity of 2 t/h, the designed exhaust gas temperature shall not be higher than . a. 230℃ b. 180℃ c. 170℃ d. Saturated steam temperature **: c 10. According to TSG G0002-2010 \"Regulations on the Supervision and Management of Energy-Saving Technologies for Boilers\", the boiler furnace walls, flue and air ducts, various thermal equipment, thermal pipelines, as well as valves must have good sealing and insulation properties. When the ambient temperature is 25°C, the surface temperature of the furnace exterior at a distance of more than 300 mm from the door (opening) shall not exceed , the furnace roof shall not exceed , and the surface temperature of various thermal equipment, thermal pipelines, and valves shall not exceed . a. 70°C b. 60°C c. 50°C d. 45°C **: c a c 11. According to the TSG G0002-2010 “Regulations on the Supervision and Management of Boiler Energy-Saving Technologies”, the selection of make-up water pumps for hot water boiler systems should meet the system’s requirements for water replenishment; generally, the volume of make-up water should not exceed 1% of the total water volume in the system. a. System circulation water volume b. System water capacity c. System leakage rate d. Total water capacity of the boiler **: a 12. The simple test of thermal efficiency under operating conditions for boilers, as specified in TSG G0003-2010 \"Rules for Energy Efficiency Testing and Evaluation of Industrial Boilers\", is a straightforward test carried out on industrial boilers in use, intended to quickly assess the actual energy efficiency of those boilers. a. Actual output b. Energy efficiency status c. Design parameters d. Key parameters **: d 13. In accordance with the provisions of TSG G0003-2010 \"Rules for Energy Efficiency Testing and Evaluation of Industrial Boilers\", the simple testing method for the thermal efficiency under boiler operation conditions is . a. Forward balance method b. Reverse balance method c. Forward balance method and reverse balance method **: b 14. According to TSG G3002-2004 \"Rules for Supervision and Inspection of Boiler Installation\", supervision and inspection of boiler installation refers to the statutory inspection of the installation process carried out by inspection and testing institutions approved by the General Administration of Quality Supervision, Inspection and Quarantine, on the basis of the self-inspection results conducted by the installation unit during the boiler installation process. a. Mandatory b. Supervisory c. Systematic d. Verifying **: a d 15. The common failure modes of the water wall headers in power plant boilers include . a. High-temperature corrosion b. Creep c. Corrosion d. Fatigue **: c d 16. Which of the following statements are in accordance with the regulations of the Rules for Periodic Inspection of Boilers? a. A boiler can be put into operation only when all the internal inspections, external inspections, and pressure tests are within their valid periods. b. When the three types of inspections for a boiler are carried out simultaneously, the internal inspection, external inspection, and pressure test should be conducted in sequence. c. When the three types of inspections for a boiler are carried out simultaneously, the internal inspection, pressure test, and external inspection should be conducted in sequence. d. When the three types of inspections for a boiler are carried out simultaneously, the pressure test, external inspection, and internal inspection should be conducted in sequence. **: a c 17. According to GB50273-2009 “Code for Construction and Acceptance of Boiler Installation Projects”, for heat exchange tubes with a nominal outer diameter not exceeding a certain value, their butt joints and bends must undergo a ball-tightness test; after this test, the tubes must have reliable sealing measures in place. a. 38mm b. 51mm c. 60mm d. 76mm **: c 18. Which of the following statements regarding the requirements for the behavior of inspection units are not specified in the \"Rules for Supervision and Inspection of the Safety Performance of Boiler and Pressure Vessel Products\"? a. The inspection agency shall announce to the enterprise under inspection the inspection outline, the procedures for the inspection work, as well as the inspectors assigned to carry out the inspection and their qualifications. b. The supervision and inspection unit shall strengthen the management of its inspectors, provide regular training for them, assess their performance, and inspect their work to prevent and promptly correct any instances of negligence in their duties. c. The inspection agency shall dispatch an inspection team to each enterprise under inspection. **: c 19. The \"Regulations on Safety Inspection Techniques for Organic Heat Carrier Boilers\" stipulate that at the outlet of organic heat carriers in liquid-phase organic heat carrier boilers, and should be installed; at the outlet of organic heat carriers in gas-phase organic heat carrier boilers, should be installed. a. Over-temperature alarm device b. Over-pressure alarm device c. Differential pressure alarm device **: a c b 20. According to DL/T438-2009 \"Regulations for Metal Technology Supervision in Thermal Power Plants\", when elbows/bends develop creep cracks or severe creep damage (or above that level), they should be dealt with or replaced promptly. a. Level 1 b. Level 2 c. Level 3 d. Level 4 **: d III. Short-answer questions (5 questions in total, 20 points in total) 1. (2 points) How does the Regulations on the Safety Supervision of Special Equipment define major accidents involving boilers? Reference**: An accident is considered a major accident under any of the following circumstances: (1) An accident involving special equipment results in 10 to 30 deaths, or 50 to 100 serious injuries, or direct economic losses ranging from 50 million yuan to 100 million yuan ； 　　(2) Boilers with a capacity of over 600 MW that have been shut down for more than 240 hours due to safety failures. 　2. (6 points) What are the minimum contents that should be included in the technical documentation on boiler energy efficiency, as specified in the \"Regulations on the Supervision and Management of Boiler Energy-Saving Technologies\"? Reference**: (1) Random factory-supplied documents for boiler products (including product energy efficiency test report) ； (2) Quality certification documents for boiler auxiliary equipment and associated devices ； (3) Boiler installation and commissioning report, energy-saving renovation documents ； (4) Energy efficiency evaluation or energy efficiency test report for boiler installation, renovation, and maintenance ； (5) Periodic energy efficiency test reports and annual operational energy efficiency test and evaluation reports for in-use boilers ； (6) Daily energy-saving inspection records for boilers and their systems ； (7) Calibration certificates for measuring and testing instruments ； (8) Inspection report on boiler water (medium) treatment ； (9) Fuel analysis report. 3. (4 points) According to the \"Rules for Energy Efficiency Testing and Evaluation of Industrial Boilers\", write down the formula for calculating thermal efficiency using the reverse balance method, as well as the meaning of each symbol in that formula Reference**: Formula for calculating reverse balance: η = 100 – (q2 + q3 + q4 + q5 + q6) (%), where q2 represents the heat loss due to flue gas, %; q3 represents the heat loss due to incomplete combustion of gases, %; q4 represents the heat loss due to incomplete combustion of solids, %; q5 represents heat loss through conduction, %; and q6 represents the physical heat loss associated with ash. 4. (4 points) In accordance with the GB/T1576-2008 standard \"Water Quality for Industrial Boilers\", under what conditions can industrial boilers rely solely on chemical treatment methods to treat the water inside the boiler? Reference**: (1) Steam boilers: Natural circulation steam boilers and combined steam/water boilers with a rated evaporation capacity of 4 t/h or less, and a rated steam pressure of 1.3 MPa or less ； (2) Pressurized hot water boilers and atmospheric pressure hot water boilers with a rated power of 4.2 MW or less (excluding pipe rack-type hot water boilers). However, the quality of steam and water after chemical addition must not affect production and daily life. 5. (4 points) Briefly describe the procedures for supervision and inspection during the manufacturing of power station boiler products, and identify which items fall under Category A supervision and inspection in this process Reference**: The supervision and inspection procedure is as follows: document review → material supervision and inspection → welding supervision and inspection → inspection of appearance and geometric dimensions → non-destructive testing supervision and inspection → heat treatment supervision and inspection → hydrostatic test supervision and inspection → safety accessories → review of factory documents → stamping of the supervision and inspection seal on the nameplate → issuance of the supervision and inspection certificate. Category A items include: “Approval procedures for design drawings”, “Certificates of material properties and re-inspection reports for main pressure parts and welding materials”, “Performance report on product weld test plates”, “Surface quality of the boiler drum base metal”, “Hydrostatic test”, “Documents at delivery”, and “Nameplate”. IV. Comprehensive Application Questions (3 questions in total, 40 points in total). Only two questions need to be answered; Question 1 is mandatory, while for Questions 2 and 3, one of them can be chosen. Answers to extra questions will not be counted. 1. (25 points) The table below lists some of the inspection items related to the water wall tubes and their headers in the internal inspection plan for the XX-220/9.8-M13 type natural circulation coal-fired boiler. Please fill in the relevant information in the “Key Inspection Items” and “Inspection Methods” columns (this boiler is used as a peak-shaving unit). Table of Inspection Items for Water Wall Tubes and Their Manifolds Sequence Number Item Key Points for Inspection Inspection Methods 1 Whether the water wall tubes in areas with high heat loads suffer from overheating, deformation, bulging, wear, high-temperature corrosion, thickening, or cracks. For macroscopic inspection, thickness measurement, expansion amount, deformation amount, tube cutting checks, and metallographic examination should be added if necessary, to determine whether there is wear or thinning in the water wall tubes near the soot blower. For macroscopic inspection, thickness measurement should be carried out if necessary, to check whether the slag prevention tube has defects such as overheating, swelling, deformation, bulging, or fatigue cracks. Macroscopic inspection, along with thickness measurement or surface flaw detection, should be conducted if needed. 4. It is necessary to check whether the water wall at the bottom of the boiler has defects such as dents, flattening, wear, cracking, or corrosion. For macroscopic inspection, thickness and deformation measurements should be added if necessary, to check whether the water wall tubes at the 5-fold flame angle suffer from defects such as overheating, deformation, swelling, or wear. For macroscopic inspection, the amount of swelling, deformation, tube cutting, and metallographic testing should be increased if necessary, to check whether there is severe corrosion on the inner and outer surfaces of the water wall header. Macroscopic inspection: where necessary, measure the thickness; check whether the internal baffles in the water wall header are intact and free from cracks. Endoscopic inspection: check whether there are any defects or cracks in the fillet welds of the water wall header tubes. Macroscopic inspection should be carried out on at least 25% of the surface area, and ultrasonic testing may be performed if necessary. Inspection of the header supports and lugs: check whether the contacts between the supports are proper, as well as whether there are any cracks in the welds between the lugs and the header. Macroscopic inspection shall be conducted; surface flaw detection shall be performed when necessary. 10. Conduct macroscopic inspection of the tank head welds and hole bridges to check for defects such as cracks; perform surface flaw detection on no less than 25% of the area, and use ultrasonic testing if necessary. 2. (15 points) In the context of the installation supervision and inspection of a power plant boiler, regarding the quality of the installation of the tanks and superheater tubes, answer the following questions: (1) After the tanks are installed in place, what installation parameters does the inspector randomly check on-site? What are the benchmark points for measuring these projects? (7 points) Key points for answering: Inspection items: Elevation, levelness, mutual distances. Measurement reference points: Elevation: 1-meter elevation mark of the steel framework; Levelness: Elevation mark of the steel framework’s collection box and the center marks at the four corners of that box; Mutual distances: Center point of the steel framework and the center mark of the collection box. (2) During the installation inspection, when examining the RT inspection film of the welds at the joints of the superheater tubes, it was found that the assessment result for one of these films given by the installation unit was incorrect. After reaching a consensus, this film was classified as grade III (100% RT inspection of the on-site welds). Please propose a solution. (8 points) Key points for answering: Handling suggestions: ① Issue the \"Special Equipment Supervision and Inspection Work Liaison Form\" (\"Special Equipment Supervision and Inspection Opinion Notice\") to require the installation unit to carry out the following tasks: a. Analyze the reasons for the defects in the defective welds and develop a repair procedure. After rework, the RT method was used to inspect the weld. b. Require the installation unit to strengthen control over the quality assessment of RT inspection films. ② Inspectors conduct a re-inspection of the pieces that have been repaired, increase the proportion of random inspections of the evaluated images, and appropriately raise the proportion of random inspections of images taken on-site. 3. (15 points) An industrial steam boiler of type DZW20-2.5-AⅡ in a certain unit is equipped with a steel-tube economizer. Please answer the questions based on the following situation. (1) Upon reviewing the operation records prior to the inspection, it was found that the deaerator of this boiler was damaged and not in use for a long period last year. Please explain in relation to this situation: Which components should be given priority during internal inspections? What testing methods are used to detect which defects? (9 points) Reference: In the case of a deaerator being out of service, the components that need to be inspected carefully include the economizer tubes and headers, as well as the boiler drum. Inspection method: Macroscopic inspection for signs of oxygen corrosion ； Endoscopy: Inspection of oxygen corrosion inside the economizer tubes and headers ； Cut the pipe as necessary to check for corrosion ； Corrosion measurement: Measures the corrosion depth of the measurable areas. (2) A review of the boiler’s operation records showed that the actual evaporation rate of the boiler was around 12 t/h, and recently the coal consumption had increased along with a rise in the flue gas temperature. In your opinion, from which aspects should we analyze the main reasons for this phenomenon? (6 points) Reference: ① The boiler is operating at low load ； ② Is the boiler scaled? ； ③ Is there ash buildup in the boiler? ； ④ Is there any short circuit in the boiler exhaust gas? ； ⑤ Is the excess air coefficient too low or too high? ； Is the wind regulation via the blower appropriate? ； ⑥ Whether the coal quality is consistent with or similar to the design.