Device for solving abnormal output of pulverized coal feeder

Abstract

The utility model discloses a powder feeder output abnormity solving device, which comprises a powder feeder connected with a controller, a timer and a bias circuit, the bias circuit and the timer are both electrically connected with the controller, the controller is connected with a power supply, the bias circuit, the timer and the controller form a new oscillation circuit, and the power supply is connected with the power supply. The input current of the pulverized coal feeder is controlled through timing of the timer and adjustment of the resistance value by the biasing circuit to bias the current, and the pulverized coal feeder has the technical characteristics of simple structure, automatic control, improvement of the safety and stability of a unit and the like.

Description

Technical Field

[0001] The utility model relates to a solution device, more specifically, to a solution device for abnormal output of a powder feeder, belonging to the field of thermal power plants. Background Art

[0002] The central storage powder making system of a thermal power plant has the advantages of fast load and pressure response, but sometimes the powder feeder may be blocked or collapsed, causing unstable adjustment of the coordination system or even oscillation, which can seriously threaten the safety of the unit. In particular, when the powder feeder collapses, the operation data of the powder feeder of a central storage thermal power unit shows that after a powder feeder collapses, the main steam pressure will increase rapidly by about 0.7MPa in 30-60S. If two powder feeders collapse at the same time, the main steam pressure will increase rapidly by about 1.4MPa in 30-60S. Under high load, overpressure is very likely to occur, which may trigger the action of the safety valve in severe cases, affecting the safety of the unit.

[0003] Therefore, once the powder feeder shows signs of powder collapse, the operator will immediately adjust the speed of the powder feeder or stop the powder feeder to prevent the powder collapse from worsening. Manual operation increases the personnel input cost and has a low response rate. Utility Model Content

[0004] In order to solve the above-mentioned problems of the prior art, the utility model provides a device for solving abnormal output of a powder feeder, which has the technical characteristics of simple structure, automatic control, and improved safety and stability of the unit.

[0005] In order to achieve the above purpose, the utility model is implemented by the following technical solutions:

[0006] A device for solving abnormal output of a powder feeder comprises a powder feeder, wherein the powder feeder is connected to a controller, and further comprises a timer and a bias circuit, wherein the bias circuit and the timer are electrically connected to the controller, and the controller is connected to a power supply, wherein a new oscillation circuit is formed between the bias circuit, the timer and the controller, and the timer is used for timing, and the bias circuit adjusts the resistance value to perform bias current control on the input current of the powder feeder so as to increase or decrease the rotation speed of the powder feeder.

[0007] Preferably, it further comprises a temperature sensor, which is located at the air-powder outlet of the powder feeder and is electrically connected to the controller.

[0008] Preferably, the bias circuit comprises a trigger, and the trigger is used to start the bias circuit.

[0009] Preferably, the trigger is an RS trigger or a D trigger.

[0010] Preferably, the bias circuit comprises a negative feedback circuit, and the feedback circuit is used to stabilize the current.

[0011] Beneficial effect: It reduces the occurrence rate of complete powder collapse in the powder feeder, reduces the workload of operators, and improves the safety and stability of the unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a principle block diagram of the utility model. DETAILED DESCRIPTION

[0013] The present invention will be further described below in conjunction with the accompanying drawings, but the present invention is not limited to the following embodiments.

[0014] like Figure 1 The figure shows a specific embodiment of a device for solving abnormal output of a powder feeder. The device for solving abnormal output of a powder feeder includes a powder feeder, the powder feeder is connected to a controller, and also includes a timer and a bias circuit. The bias circuit and the timer are electrically connected to the controller. The controller is connected to a power supply. The bias circuit, the timer, and the controller form a new oscillation circuit. The bias circuit adjusts the resistance value to bias the current to control the input current of the powder feeder through the timer timing. The bias circuit can adopt a conventional circuit in the prior art. If other functions need to be added, corresponding components can be added. The specific design of the bias circuit is not limited to the content of this application.

[0015] In actual use: through the bias circuit, timer and controller design, it is possible to add a bias in the speed command loop of the powder feeder. For example, if the bias is -20% (such as for the current), when the signs of powder collapse appear: the primary air powder speed is lower than 25m / s or the primary air powder outlet temperature is lower than 156℃

[0016] (The wind speed and temperature monitoring of the powder are not the focus of this application, and corresponding component sensors can be added according to actual needs.) In conjunction with the timer, the controller controls the increase of a -20% bias for 40 seconds. After 40 seconds, the bias returns to 0. At this time, if there are still signs of powder collapse, the delay is 40 seconds, and the bias is triggered again with a minus 20% bias. After 40 seconds, it returns to 0, and so on and so forth, forming a similar oscillation circuit until the wind speed of the powder is higher than 28m / s or the outlet temperature of the powder is higher than 158°C. After the powder feeder operates normally, the bias circuit no longer operates.

[0017] A preferred embodiment further includes a temperature sensor, which is located at the air-powder outlet of the powder feeder. The temperature sensor is electrically connected to the controller. Real-time monitoring by the temperature sensor is used to start the bias circuit and reduce manual operation costs.

[0018] In a preferred embodiment, the bias circuit includes a trigger, the trigger is used to start the bias circuit, the trigger is an RS trigger or a D trigger, the timing is performed by a timer, and the bias circuit is triggered to work by the trigger, so as to achieve efficient work, simple structure and strong practicality. The RS trigger is a circuit composed of two feedback-coupled NOT gates or NAND gates, with two input terminals and two output terminals, and the output periodicity control is achieved through the continuous setting (Set), resetting (Reset) and holding (Hold) of the RS trigger.

[0019] In a preferred embodiment, the bias circuit includes a negative feedback circuit, and the feedback circuit is used to stabilize the current. The existing feedback circuit can be a conventional circuit. In practice, corresponding components can be added according to actual needs to realize additional functions.

[0020] Finally, it should be noted that the present invention is not limited to the above embodiments, and there are many variations. All variations that can be directly derived or associated with the content disclosed by ordinary technicians in this field should be considered as the protection scope of the present invention.

Claims

1. A device for solving abnormal output of a powder feeder, comprising a powder feeder, characterized in that: The powder feeder is connected to a controller, and also includes a timer and a bias circuit. The bias circuit and the timer are electrically connected to the controller. The controller is connected to a power supply. The bias circuit, the timer and the controller form a new oscillation circuit. The timer is used to count the time, and the bias circuit adjusts the resistance value to control the input current of the powder feeder to increase or decrease the speed of the powder feeder. By means of the bias circuit, the timer and the controller, it is possible to add a bias in the speed command loop of the powder feeder.

2. A device for solving abnormal output of a powder feeder according to claim 1, characterized in that: The invention also comprises a temperature sensor, which is located at the air-powder outlet of the powder feeder and is electrically connected to the controller.

3. A device for solving abnormal output of a powder feeder according to claim 1 or 2, characterized in that: The bias circuit includes a trigger, and the trigger is used to start the bias circuit.

4. A device for solving abnormal output of a powder feeder according to claim 3, characterized in that: The trigger is an RS trigger or a D trigger.

5. The device for solving abnormal output of a powder feeder according to claim 1, characterized in that: The bias circuit includes a negative feedback circuit, and the feedback circuit is used to stabilize the current.

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