Waste heat power generation system generator bearing shell strain the cause of the accident and measures

Waste heat power generation system generator bearing shell strain the cause of the accident and measures - 2019 10 - 24 Zhu Yongli 1, accident after a company lose electric factory, due to lightning & 2 times; 5000 t/d clinker line 18 mw generating unit jump stop, the lubricating oil pressure is 0. 10 mpa dropped to zero. 04 mpa, dc oil pump chain failed to open. Operator on duty to pass control frame start dc oil pump, found that the dc pump unprepared to boot, they immediately contact field personnel, required by the machine start dc oil pump, also did not succeed. And through the control of work station to start the emergency button boot, make dc oil pump, oil pressure returned to normal, the steam turbine no. 1, 2, radial tile temperature from 106 ℃, 115 ℃ respectively dropped to normal gradually. After power supply recovery, clinker line running normally, the unit began to flush, when the rotation speed in 0 ~ 1200 r/min unit vibration and bearing temperature is normal, when the speed from 1200 r/min up to 2500 r/min, the vibration increased, the no. 2 and no. 3 bearing vibration rose to 69, respectively. 46μ M and 51. 01μ M, no. 1, no. 2 bearing shell temperature rose to 57. 6 ℃, and 64. 6℃。 Field personnel to play the floodgate, inspection found no. 1, no. 2 and no. 3 bearing shell has different degree injury ( FIG. 1) , need to be replaced. 2, the reason analysis of waste heat power generation DCS cabinet power supply situation as shown in figure 2. Figure 2, each side cabinets by the two road AC220V power supply, are redundant. The first all the way for the UPS power supply, the first 2 for mains, DI signal COM power provided by the DCS cabinet 48 v power supply module, each piece of 24 v power supply module and 48 v power supply module are output to power supply alarm relay all the way, see figure 3. Alarm signal through the terminal to DCS DI points, and have the message in the operating screen, when any abnormal output power supply module, operation screen of words' system configuration 'button will turn red, as shown in figure 4 parts diagram. Figure 4 and figure 5, each side cabinets by the two road AC220V power supply, are redundant. The first all the way for the UPS power supply, the 2 for the grid. COM DI signal power supply provided by the DCS cabinet 48 v power supply module. Figure 6 and figure 7, with similar boiler control cabinet, each piece of 24 v power supply module output to power supply alarm relay all the way, the control cabinet of the 48 v power supply and control cabinets from the other side of the 48 v power supply's output to power supply alarm relay all the way, and alarm through terminals respectively to T11 T12 DI signal cabinet, and have the message in the operating screen, when any abnormal output power, operating picture words' system configuration 'button will turn red. 48 v power supply module with the use of boiler control cabinet some differences: both sides of the steam turbine control cabinet ( T11 and T12) DI COM power signal, and placed in T11 separately by the two pieces of T12 48 v power supply module provides, cabinet and T12 control cabinet by T11 the DYZJ terminals on the reverse of the jumper to implement redundancy, shown in figure 8. Is caused by the above analysis shows that this is the main reason of the generator bearing injury accidents: factory, after losing electricity dc oil pump unprepared, central chain can't start automatically, in turbine oil bearing moment of strain. Through inspection and T12 DCS control cabinet T11 tank between two road DC48V power ( All the way to the utility, all the way to UPS power supply) Not through short wires connected, cannot have the effect of mutually standby, when factory, after losing electricity system in DCS control cabinet COM power DC48V power losing electricity, dc oil pump unprepared, central images cannot be started leading to the accident; At the same time, the operator on duty after found that dc oil pump did not start automatically, instead of through work station emergency button to start immediately contact the boot, delayed dc oil pump start-up, the best time of a moment lack of bearing or bearing strain caused by accident. 3, preventive measures ( 1) In order to strengthen the management of on-site equipment installation, installation of new unit wiring, to urge the contractor in accordance with the construction drawings, debugging personnel should be confirmed according to the needs of design, check the equipment of the chain, protection, such as is normal, and to allow the unit to boot operation. （ 2) To draw lessons and accidents in accordance with the design requirements for organize regular inspection on the protection of the equipment or chain, confirm, for similar as spare power supply each other down, equipment simulation experiment was carried out at the right time. （ 3) Strengthen control of the skills of operating personnel training, master the emergency electric operation, the operator can immediately after losing electricity in the plant through the work station emergency button to start the dc oil pump, the host equipment malfunction or unpredictable consequences own professional skills, to stop treatment as soon as possible, so as to avoid accidents. （ 4) In downtime or equipment abnormal cases, did not find out why it is forbidden to boot up again, to prevent the failure or accident expanding. Source: the new century cement herald