How much do you know about the thermal protection of the few thermal power plant grinding balls mill

Although the grinding balls mill is used in large units is relatively small, but I personally still prefer the grinding balls mill, why, compared to other coal mills, the failure rate of the grinding balls mill is still low, but the floor space, the power consumption of the coal mill is indeed high, and finally has to withdraw from the historical stage, at present, there are still small units in many parts of China, the application of grinding balls coal mill, so today we will explain to you about the thermal protection of the grinding balls mill:

Conditions for coal mill tripping?

1. The powder discharger trips

2. The oil level of the high tank is low

3. The bearing temperature of the coal mill is 42°C high

4.6KV plant power interruption

The above four just tell you the conditions for the tripping of the coal mill, compared with the trip conditions of medium speed grinding and fan grinding at every turn, it can be said that it is also very friendly to our exam, isn't it, at the same time, in order to ensure the safe operation of the grinding balls mill, we have also improved other places:

1. The high oil tank of the coal mill is equipped with a remote liquid level timer, which converts the oil level signal from DCS into a switching signal to participate in the oil level joint pump, and there is no remote liquid level timer, and the time relay joint pump function is added to ensure that when the oil level float in the high oil tank fails, the oil pump of the thin oil station can be reliably connected.

2. In order to improve the reliability of the temperature protection of the coal mill bearing, the fault-tolerant design is adopted in the logical design of temperature protection, that is, the faults that are easy to occur in the operation of the temperature measurement link are considered as much as possible, and the wrong temperature signal is identified by pre-set logical measures to prevent the protection system from misoperation, and the temperature quality judgment parameters are fixed as follows: rate limit: 20 °C/S; Amplitude limit: lower limit: 0°C, upper limit: 150°C.

3. Increase the coal mill bearing temperature high alarm and change rate alarm, the alarm fixed value is as follows: bearing temperature high alarm fixed value: 40 °C/S, rate change alarm fixed value: 0.3 °C/S

4. The bearing temperature of the coal mill of the same unit should be designed as one coal mill corresponding to one module, so as to avoid the bearing temperature of two or more coal mills on the same module, and prevent problems in one module and cause multiple coal mills to trip.