Safety Evaluation II of the hottest thermal power

Safety evaluation of thermal power plant (II)

6) overvoltage protection device and grounding device. ① Whether the protection scope, design and installation of lightning rods (wires) of buildings and structures that should be equipped with direct lightning protection devices meet the requirements of safe operation; ② Whether the neutral point overvoltage protection of 10kV and above main transformers (including high-voltage auxiliary standby transformers) is perfect; ③ Whether the grounding resistance of grounding is tested according to the specified period; ④ Whether the grounding down lead and grounding corrosion of outdoor high-voltage electrical equipment have been excavated and sampled; ⑤ Whether there is hidden danger of ferroresonance overvoltage in the main system and high-voltage auxiliary power system

(7) whether there are serious defects or hidden dangers in 3KV and above high-voltage motors (after the accident, if there are no incremental measures at a rate of more than 12% every year, and the repair and operation have not been more than half a year, it will be evaluated as having serious defects)

(8) safety facilities: ① whether the high-voltage electrical equipment (both single and including transformers) installed indoors with an oil volume greater than 100kg and outdoors with an oil volume greater than 1000kg are equipped with oil storage (or oil retaining) and oil drainage facilities that meet the requirements; ② Whether the measures against small animals in high-voltage distribution room, transformer room and low-voltage power center are perfect; ③ Whether the fixed barrier size and safety distance of high-voltage live parts meet the requirements, and whether they are complete, closed and locked tightly; ④ Whether there is rain leakage, water leakage or pulverized coal pollution in the high-voltage distribution room, transformer and low-voltage power center

(9) equipment number and mark. ① Whether the high-voltage switchgear (circuit breaker, disconnector and grounding switch) is equipped with a number plate with double numbers (dispatching number and equipment, line name), and the handwriting is clear and the color is correct; ② Whether the names of the control panel in the main control (combined control, single control, centralized control) and the control switch, button, instrument, fuse and secondary circuit pressing plate on the instrument panel are complete and clear; ③ Whether the permanent signs such as "no climbing, high voltage danger" on the outdoor structure and "stop, high voltage danger" on the partition door inside the house are complete and clear

(10) technical data. ① Whether the account of high-voltage equipment is complete; ② Whether the maintenance records and overhaul summary of high-voltage equipment are complete

4. Relay protection and automatic device

(L) whether the configuration of generator, main transformer, high-voltage auxiliary transformer (including high-voltage auxiliary standby transformer) busbar, circuit breaker failure, non full phase, 500kV reactor and 110kV and above line protection devices comply with the regulations and can be put into operation normally. Whether the protective devices that have been operated have formulated complete, complete and in line with the actual operation procedures on site, and whether the operators have mastered them

(2) whether the annual verification plan of relay protection and automatic device is prepared on schedule, whether the components of relay protection and automatic device are regularly verified according to the regulations and verification plan, and whether the verification records are complete

(3) whether the protection device of each element meets the requirements of anti accident measures of Guodian Corporation, and provincial companies

(4) whether the differential protection vector test meets the requirements, is correct, and whether the differential voltage is within the normal range

(5) whether the fault recorder and fault sequence recorder are normally put into operation and in good working condition

(6) the relay, connecting strip, test terminal, operating power fuse, terminal strip, etc. on the protection panel (cabinet) are or meet the safety requirements (including whether the name and mark are complete and clear)

(7) whether the relay protection setting value change seriously implements the setting value notice system, and whether each protection setting value is consistent with the setting order

(8) whether the relay protection mechanism has the operation mode diagram of primary system and plant system under normal conditions, accident conditions and maintenance conditions

(9) whether the relay protection organization prepares the setting scheme of relay protection and automatic devices of machine transformer unit, main system and auxiliary power system according to various operation mode diagrams prepared by the operation Department, and whether the approval procedures comply with the regulations, and whether the setting scheme is revised in time for important equipment changes

(10) whether the relevant records of on-site relay protection setting book (card), relay protection equipment abnormal operation, input and exit, and action conditions are complete and whether the content is complete

(11) whether there are design drawings, approval documents and records for changes and improvements of protection and automatic devices

(12) whether there are main equipment relay protection principle wiring diagram, deployment diagram and terminal strip diagram on site, and whether they are in line with the actual situation

(13) it is necessary to regularly test whether the protection of technical parameters, such as high-frequency protection, is tested according to the regulations, and whether the records are complete, correct and serious

(14) whether the correct action rate of protection meets the requirements of the superior, and whether there has been protection maloperation accident of main system and main equipment with unknown causes during the evaluation period

(15) whether to fill in the statistical analysis report of relay protection action on time

5. DC system

(L) battery. ① Whether the battery terminal voltage, electrolyte specific gravity, liquid level and room temperature are within the normal range, whether they are measured according to the specified interval, and whether the data are accurate and well recorded, whether the battery terminal voltage is maintained and less maintained, and whether the battery electrolyte specific gravity and liquid level are regularly detected; ② Whether the battery plate is bent, fallen off, vulcanized, pole corrosion and other abnormal conditions, and the alkaline battery has alkali creeping phenomenon; ③ Whether the floating charge voltage or current adjustment control of the battery pack in floating charge operation is appropriate; ④ Regularly conduct check discharge or full capacity discharge, and check whether the cost and risk can be reduced to 50% and 80% of the rated capacity of the battery under the specified termination voltage, and charge evenly according to the regulations; ⑤ Whether the electrical equipment in the battery room is explosion-proof and whether the ventilation facilities are good

(2) DC system operation mode and working condition. ① Whether the DC bus voltage exceeds the normal range; ② Whether the insulation resistance of the DC system to the ground is often maintained above 0.2 megohm (220 system) and 0.1 megohm (110V system), and whether the DC system has the defect of mutual series connection between the signal circuit and the control circuit; ③ Whether there are actual DC system wiring diagrams and network diagrams on site, and indicate whether the normal operation mode, system wiring and operation mode are reasonable; ④ Whether the safety setting values at all levels of the DC system are regularly calibrated to meet the selective action requirements, whether there are spare fuses of various specifications on site, and whether the used fuses have passed the sampling inspection

(3) whether the measurement part and signal part of the insulation monitoring device of the DC system are normally put into operation, and whether the DC bus voltage monitoring device is normally put into operation

(4) whether the performance of silicon rectifier floating charge and periodic charge device is perfect and whether there are serious defects

(5) whether the functions of emergency lighting and automatic switching device are normal

(6) whether other anti accident measures of DC system have been implemented

6. Condition of cables and structures for cables (including thermal control cables)

(1) whether DC withstand voltage and leakage current tests are carried out for power cables above 2KV according to the specified cycle, and whether insulation resistance measurement is carried out for rubber cables according to the regulations

(2) whether the insulation resistance of power cables below 1kV is measured by shaking according to the specified period

(3) whether the wires are inspected according to the specified cycle and complete records are made

(4) whether the maximum load of cable after equipment capacity increase exceeds the allowable carrying capacity after cable design and environmental temperature, soil thermal resistance, multiple cables in parallel and other factors

(5) whether the plugging and drainage facilities of cable tunnels and cable trenches are in good condition without ponding, oil, ash, powder and debris

(6) whether the lighting of cable interlayer and cable tunnel is complete and good, and whether the interlayer tunnel with height less than 2.5m adopts safe voltage power supply

(7) whether the cable holes from the cable interlayer of the control room (including main control, control, single control and centralized control) to the steam turbine room, boiler room, cable shaft (including the inside of the shaft), instrument panel and control room are sealed tightly and meet the requirements

(8) whether the sectional fire-retardant measures of the main tunnel of the wire and the main channel of the overhead wire meet the requirements

(9) are fire-resistant isolation measures taken or flame-retardant cables replaced for particularly important cables (such as cables from battery to DC bus, DC lubricating oil pump, sealing oil pump cables, etc.)

(10) whether the cable laying meets the requirements of the regulations

(11) whether the cable list is complete, and whether the registration content includes the number, starting and ending points, type, voltage, number of cores, length, etc. of each cable

(12) whether the design and installation drawings of cable fire prevention and flame retardant measures are complete

7. Communication equipment status

(1) whether the lightning protection measures of microwave tower comply with the regulations

(2) whether the metal shells and metal components of all equipment in the communication machine room are well grounded and whether the grounding resistance meets the requirements

(3) whether the technical condition of communication standby power supply equipment such as battery, electric or gas (diesel) generator, inverter, etc. is good

(4) whether the automatic switching device of standby power supply is in good condition

(5) whether the terminal security devices of communication cables and overhead open lines are complete and meet the requirements

(6) whether the air pressure of each air closing section of the communication cable is maintained within the specified range and whether the inflation pump is in good condition

(7) whether the drawings, test records and operation logs of communication system and equipment are complete

(8) electrical others

(IV) thermal equipment safety evaluation piece

1 Boiler part

(L) thermal protection and automatic device. ① Whether the safety monitoring device of boiler combustion chamber of 400t/h and above is normally put into operation and acts on boiler shutdown; Whether the simple fire-extinguishing protection of boilers above 200t/h and less than 400t/h is normally put into operation and acts on boiler shutdown. Whether the flame detection devices of boilers with various capacities are normal and reliable; ② Whether the water shortage protection of the drum boiler and the water cut-off (low flow) protection of the once through boiler are normally put into operation and act on the shutdown of the boiler; ③ Whether the feed water automatic regulating device, main steam temperature, reheat steam temperature and combustion automatic regulating device are put into operation and have good performance; ④ During the evaluation period, whether the main thermal protection and automatic devices have hidden dangers of unit tripping or other consequences caused by unexplained misoperation and refusal to operate. ⑤ Whether the interlock devices of combustion and pulverization system (suction, delivery, discharge and grinding) are normally put into operation

(2) monitoring alarm devices and main instruments. ① Whether the design, installation and operation of remote water level gauge meet the requirements; ② Whether the control room is equipped with reflectors or industrial televisions that directly monitor the flame; ③ Whether the following thermometers are normally put into operation, whether the measuring points and positions meet the requirements, and whether the corresponding relationship between the indicated values and the indications of relevant instruments is normal: superheater outlet, reheater inlet and outlet, front and rear of desuperheater, water supply, steam drum wall (inside and outside, up and down), reheater inlet flue gas, smoke exhaust, superheater, reheater pipe wall, fuel oil in front of oil fired furnace, intermediate point of once through furnace and outlet header working medium of water-cooled wall, Air powder mixture at the outlet of coal mill and pulverized coal bunker; ④ Whether all the following pressure gauges are put into operation, and whether the corresponding relationship between the indicated values and relevant instruments is normal: steam drum, front and rear of feed water control valve, inlet and outlet of superheater and reheater, in front of once through Boiler Start-up Separator and block valve of primary steam water system, oil supply and return of oil fired boiler, differential pressure between inlet and outlet of boiler water circulating pump of forced circulating boiler, compressed air source for control of various boiler safety valves, pressure gauge in front of each safety valve, Combustion chamber pressure gauge (including not installed)