Automatic monitoring and control device for exhaust pipe of boiler water pipeline

Abstract

The utility model discloses an automatic monitoring and controlling device for an exhaust pipe of a boiler water pipeline, which comprises the exhaust pipe communicated with the boiler water pipeline, an automatic valve is arranged on the exhaust pipe, the exhaust pipe is communicated to a deflation collecting box, a measuring cylinder is arranged behind the automatic valve on the exhaust pipe, an electrode is arranged in the measuring cylinder, and the electrode is connected with the exhaust pipe. And the automatic valves and the electrodes are communicated with the local control box through cables and are controlled by a whole-plant DCS (Distributed Control System). The utility model is used for solving the problem that the exhaust pipe of the water side pipeline cannot be automatically monitored and turned off when the boiler is started to feed water, meets the requirement of automatic start-stop control, monitors the inner leakage of the valve, and avoids the increase of water replenishing amount and the reduction of unit operation efficiency due to leakage.

Description

Technical Field

[0001] This utility model relates to the fields of power and chemical technology, and in particular to an automatic monitoring and control device for the exhaust pipe of a boiler water pipeline. Background Technology

[0002] With the increasing automation levels across various industries, thermal power plants are also moving from partial automation to full-process intelligent automation. The Automatic Start-Stop System (APS) is a program control system capable of automatically completing the unit start-up and shutdown process under all operating conditions and throughout the entire process. In particular, it improves the accuracy and standardization of unit start-up and shutdown, greatly reduces the workload of operators, reduces the possibility of misoperation, shortens unit start-up and shutdown time, and improves the overall automation level of the unit. When filling the boiler with water, the air in the water pipes needs to be vented to eliminate air resistance and reduce vibration and noise. Therefore, it is required that the boiler water pipes be designed with vent pipes at high points, and valves be installed on the vent pipes. Generally, manual valves are used, requiring manual monitoring and closure, which cannot meet the requirements of APS and wastes manpower. If only automatic valves are installed without monitoring methods, the automation requirements are not met, and manual intervention and judgment are still required. Utility Model Content

[0003] To address the aforementioned technical problems, this utility model presents an automatic monitoring and control device for the exhaust pipe of a boiler water pipeline. This device solves the problem of the exhaust pipe on the water side not being automatically monitored and shut off during boiler startup and water intake, meeting the requirements for automatic start-up and shutdown control. Simultaneously, it monitors internal valve leakage to prevent increased water replenishment due to leakage, thus avoiding reduced unit operating efficiency.

[0004] The present invention adopts the following technical solution:

[0005] An automatic monitoring and control device for the exhaust pipe of a boiler water pipeline includes an exhaust pipe connected to the boiler water pipeline, an automatic valve installed on the exhaust pipe, and an exhaust collection box connected to the exhaust pipe. A measuring cylinder is installed behind the automatic valve on the exhaust pipe, and an electrode is installed inside the measuring cylinder. The automatic valve and the electrode are connected to a local control box via a cable and controlled by the plant's DCS system. The electrode utilizes the difference in conductivity between water and air or steam. When water flows through the electrode, the electrodes are conductive through the water, allowing current to flow; otherwise, in the presence of air or steam, the circuit is broken. The electrode is connected to the local control box via a cable. The local control box sends a signal to the plant's DCS system based on the circuit connectivity status. The DCS system then controls the automatic valve and sends an alarm signal based on the operating status. During boiler startup and water filling, water flows through the exhaust pipe once the air is expelled. When the water flows through the electrode, the circuit is conductive, and the local control box sends a signal to the plant's DCS system. The DCS system then sends a command signal to control the opening and closing of the automatic valve. During normal operation, there is no water in the exhaust pipe. When the valve leaks, water flows through the electrode and sends a signal to the DCS system, which then issues an alarm.

[0006] Preferably, the measuring cylinder has two electrodes to avoid affecting the judgment due to damage to a single electrode.

[0007] As a preferred option, a DCS alarm signal is added. If water is present in the pipe during normal operation, an alarm signal is issued, indicating that there is a possibility of internal leakage in the valve.

[0008] Preferably, the exhaust pipe and measuring cylinder are installed at an angle to drain water from the pipe.

[0009] Preferably, the automatic valve is an electrically controlled valve.

[0010] The beneficial effects of this utility model are: (1) Because a monitoring device is used on the exhaust pipe, the emission status of the gas in the pipe during startup can be monitored, avoiding incomplete exhaust affecting safe operation and water waste caused by human negligence in forgetting to close the valve. The monitoring device can promptly judge and shut off the exhaust pipe valve, meeting the requirements of the boiler self-starting and stopping control system; (2) It avoids the situation where valve internal leakage cannot be detected in time. Valve internal leakage occurs inside and is generally not observable from the outside. With the monitoring device, when water flows through the electrode in the pipe, the circuit is connected and an alarm signal is issued, which can promptly detect valve internal leakage and ensure the safe and stable operation of the unit. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of a structure according to Embodiment 1 of this utility model;

[0012] Figure 2 This is a schematic diagram of a structure of Embodiment 2 of this utility model;

[0013] In the diagram: 1. Water pipe, 2. Exhaust pipe, 3. Automatic valve, 4. Measuring cylinder, 5. Electrode, 6. Local control box, 7. Plant-wide DCS system, 8. Cable, 9. Venting collection box. Detailed Implementation

[0014] The technical solution of this utility model will be further described in detail below through specific embodiments and with reference to the accompanying drawings:

[0015] Example 1: As Figure 1 As shown, an automatic monitoring and control device for the exhaust pipe of a boiler water pipeline is disclosed. The device comprises an automatic valve 3, a measuring cylinder 4, an electrode 5, a local control box 6, and a cable 8. The electrode is installed inside the measuring cylinder. One end of the measuring cylinder is welded to the exhaust pipe inlet, and the other end is welded to the exhaust pipe outlet. The end of the exhaust pipe is connected to a venting collection box 9. The electrode 5 is connected to the local control box 6 via cable 8. The local control box 6 is connected to the plant's DCS system 7 via cable 8. The plant's DCS system 7 is connected to the automatic valve 3 via cable 8.

[0016] During boiler startup and water filling, when the air in the exhaust pipe is purged and water flows through the electrode, the circuit becomes conductive, and the local control box sends a signal to the plant's DCS system. The DCS system then sends a command signal to control the automatic valve opening and closing. During normal operation, there is no water in the exhaust pipe. When there is internal leakage in the valve, water flows through the electrode, causing the circuit to become conductive again, sending a signal to the DCS system, which then issues an alarm.

[0017] Example 2: This example differs from Example 1 in that it is applied to multiple exhaust pipes; otherwise, it is the same as Example 1. Figure 2 .

[0018] The embodiments described above are merely several preferred solutions of this utility model and are not intended to limit this utility model in any way. Other variations and modifications are possible without departing from the technical solutions described in the claims.

Claims

1. A device for automatic monitoring and control of exhaust pipe of boiler water pipeline, comprising an exhaust pipe in communication with the boiler water pipeline, an automatic valve installed on the exhaust pipe, and the exhaust pipe in communication with a gas exhaust collecting tank, characterized in that, The exhaust pipe is provided with a measuring cylinder behind the automatic valve, the measuring cylinder is provided with an electrode, the automatic valve and the electrode are connected with a cable, and a local control box is controlled by a DCS system of the whole plant.

2. The automatic monitoring and control device for exhaust pipe of boiler water pipe according to claim 1, characterized in that, The electrode in the measuring cylinder is provided with two electrodes.

3. The automatic monitoring and control device for exhaust pipe of boiler water pipe according to claim 1, characterized in that, The exhaust pipe and the measuring cylinder are installed with a slope.

4. The automatic monitoring and control device for exhaust pipe of boiler water pipe according to claim 1, characterized in that, The automatic valve is an electric control valve.

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