15 kilowatt boiler induced draft fan normal operation, the current is too large, what is the cause o

Two reasons: 1. After the boiler is repaired, the resistance of the induced air system decreases, resulting in insufficient system resistance;

2. The fan is running in a cold state, and the air density at this time is; When the boiler is running, the exhaust gas temperature is 180-200 degrees, and the air density at this time is about that, so the current = 50 * , 2 = when the induced draft fan is running in a hot state.

The induced draft fan is a driven fluid machine that relies on the input mechanical energy to increase the gas pressure and discharge the gas. Induced draft fan is a machine that relies on the input mechanical energy to increase the gas pressure and discharge the gas, and it is a driven fluid machine.

Induced draft fans are widely used for ventilation, dust removal and cooling in factories, mines, tunnels, cooling towers, vehicles, ships and buildings; ventilation and induced air for boilers and industrial furnaces; cooling and ventilation in air-conditioning equipment and household appliances; drying and selection of grains; Wind tunnel wind source and hovercraft inflation and propulsion, etc.

The working principle of the induced draft fan is basically the same as that of the turbine compressor, but due to the low gas flow rate and the small change in pressure, there is generally no need to consider the change of gas specific volume, that is, the gas is treated as an incompressible fluid.

I don't know how the boiler induced draft fan is used, but if it has been determined that the current is indeed excessive, then it is necessary to see if the motor is out of phase or overloaded. Or it's the motor itself.

The reason for the sudden increase in the current of the induced draft fan during boiler operation Hello, unlike other products, boiler induced draft fans are usually used for several years or even longer. By the noise quietly in the use of the time is different, ** uneven. After the thermal power plant starts the Shenyuan boiler, the boiler fan will generate a large current under the drive of the motor.

If it's just a simple analysis, it's hard to find the real cause. We may have to wait until the boiler stops running, unless there is an obvious reason. Reasons for the sudden increase in current during the operation of the boiler induced draft fan:

When the boiler induced draft fan trips many times and the operating current of the measured motor is normal, the fault of electrical components such as thermal relays should be considered; During the test run of the fan, the electrician should cooperate closely on site to check whether the starting and running current values of the motor are abnormal to avoid fault loss or complication. When the current exceeds the standard, the impeller installation reaction is the root cause of the fan motor tripping. Therefore, when assembling or repairing the two-way symmetrical inlet impeller of the fan, attention should be paid to the installation direction of the impeller and mark it.

The impeller is usually mounted in such a way that the blades are arched forward and the concave side is facing backwards.

The reason for the sudden increase in the current of the induced air ballast during the operation of the boiler is that the direction of the impeller is the root cause of the current of the fan motor tripping. Therefore, when the fan jumps the spine breaker many times and the measured motor running current is normal, it should be considered that the cause of the fault is the problem of electrical components, such as caused by the malfunction of the thermal relay; After the test run of the assembled fan, I hope it can help you, if my answer is helpful to you, please also give a like (comment in the lower left corner), look forward to your like, your efforts are very important to me, and your support is also the driving force for my progress. Finally, I wish you good health and a good mood!

(1) The reverse installation of the impeller direction is the root cause of the current of the ventilator motor tripping. Therefore, when assembling or overhauling the ventilator of the two-way symmetrical air inlet impeller, we must pay attention to the installation direction of the impeller and mark it, and the general impeller is assembled in the backward bending direction, that is, the blade arch back forward, and the recess is backward, which must be specifically stated in the manufacturer's installation manual.

2) When the fan trips many times and the measured motor running current is normal, it should be considered that the cause of the fault is a problem with electrical components, such as a malfunction of a thermal relay; During the trial operation after assembling the fan, the electrician should go to the site to cooperate closely to detect whether the motor starts and runs the current value is abnormal, so as to avoid loss or complication of failure.

3) When assembling the ventilator, attention should be paid to the installation size, belt tightness and the gap between the impeller and the collector.

If the current increases, it must be an increase in air volume or a mechanical failure.

If there is automatic control of the induced draft fan, the sudden increase in the current of the induced draft fan may be a leak of the reheater!

1) The reverse installation of the impeller direction is the fundamental cause of the fan motor current tripping beyond the standard. Therefore, when assembling or overhauling the ventilator of the two-way symmetrical air inlet impeller, we must pay attention to the installation direction of the impeller and mark it well.

2) When the fan trips many times and the measured motor running current is normal, it should be considered that the cause of the fault is a problem with electrical components, such as a malfunction of a thermal relay; During the trial operation after assembling the fan, the electrician should go to the site to cooperate closely to detect whether the motor starts and runs the current value is abnormal, so as to avoid loss or complication of failure.

3) When assembling the ventilator, attention should be paid to the installation size, belt tightness and the gap between the impeller and the centralized chain.

There are many reasons for the sudden vibration of the induced draft fan, if it is a fine noise, it can be judged that the gap between the fan bearing or the motor bearing is too large, if it is an obvious macroscopic vibration, and it is sudden, there may be the following reasons:

1. The anchor screws are loose. Tighten it if you can't confirm it;

2. The coupling clearance is too large. After the machine is stopped, check whether there is any change in the clearance with a hand-turned car, and then adjust it. Because I don't know what the transmission mode is, I can't give a specific situation;

3. The impeller is unbalanced, which is the most likely. Because the possibility of grinding leakage is not large, but it cannot be ruled out, because I don't know what the effect of dust removal and search is and how long it will be used, so it can't be determined. In addition to the wear and tear of the impeller, the impeller is also stuck with ash and dirt on the impeller, some of which fall off, and some of which do not fall off, so that there will be sudden vibration.

The solution is to open the inspection port and clean the ash on the impeller;

4. The impeller is deformed, which is not very likely, but it is not ruled out;

5. The throat, that is, the impeller inlet, is deformed, resulting in turbulent intake and vibration. When you open the fan deflector, you can see that if the stove is changed, the heating is corrected.

The rated operating current is what you mean by excessive current? The TV at home is hot to the touch, not to mention the motor, in addition to electrothermia, mechanical friction will also heat, so, since you want to ask questions, at least explain how high the current is, how much heat, right? If it's just that your hands are hot to the touch, it's just normal within normal.

There can be two reasons for excessive current, one is that the load is too large, that is, the damper is too open. The other is equipment problems, lubricating oil, motor quality problems, etc., it is best to find equipment personnel to check together.