The Application of Infrared Thermometers in the Railway Industry
Limitations of traditional temperature measurement
After the electrical equipment is energized, the temperature of the equipment will change, and its heat generation is proportional to the square of the energized current; The temperature changes of bearings in rotating electrical and mechanical equipment are closely related to the cooling medium, sliding friction, and rolling friction... Any type of equipment failure is often manifested in the form of temperature changes. By detecting changes in equipment temperature, it is of great significance to promptly determine and detect any abnormalities or malfunctions in the equipment, improve its operational reliability, extend its service life, and avoid equipment damage and personal injury. As is well known, the traditional method of temperature measurement for equipment inspection is to use mercury thermometers and alcohol (kerosene) thermometers. Mercury thermometers are greatly affected by electromagnetic fields, and alcohol (kerosene) thermometers have significant errors when measuring equipment with higher temperatures. Therefore, the new equipment temperature measurement tool - far infrared thermometer - has been widely adopted.
Application Status of New Far Infrared Temperature Measurement Technology
Far infrared temperature measurement technology is a new non-contact testing technology introduced from European and American countries in China in recent years, which has been widely adopted in the power industry. The far-infrared temperature measurement technology is mainly used in power plants and substations to measure the temperature of electrical equipment, that is, to measure the heating and overload conditions caused by the incoming current of electrical equipment, the faults and overheating of the disconnector and circuit breaker fracture and metal connection parts, as well as the cable head overheating faults. However, there is relatively little use for measuring the bearing temperature of rotating equipment, checking for leaks in sealed containers, detecting steam water separators, and identifying insulation faults in process pipelines or other insulation processes. In my work, I encountered several typical and representative equipment failures discovered by measuring the temperature of the non flow part of the equipment.
3 Practical Application Examples
In May 2003, a large steam turbine generator unit in a certain factory was connected to the grid after maintenance, and the vacuum of the steam turbine condenser could not be adjusted to the standard data for a long time. The unit load was affected, and the thermal pipeline was subject to oxidation corrosion, which would affect the equipment life. After multiple inspections of the thermal system, the duty personnel did not find the fault. They reviewed the relevant information during the unit overhaul and used infrared thermometers to check and measure all the operating equipment replaced during the overhaul one by one. After measuring the temperature of the front, back, top, bottom, left, and right of the condenser air valve that should be fully opened during normal operation of the unit, they found that the condenser air valve was not fully opened, Causing prolonged low vacuum and high dissolved oxygen in the steam turbine! Immediately fully open the valve, and the dissolved oxygen of the unit immediately decreases to 8-9 micrograms, ≤ 10 micrograms at the rated load of the unit, meeting the requirements for normal operation of the unit. This measurement indicates that the infrared thermometer has an important reference role in checking the opening degree of the valve.
