A nitrogen charging system for a boiler gas duct

Abstract

The utility model belongs to boiler pipeline technical field, specifically disclose a kind of boiler gas pipeline nitrogen charging system, including gas pipe and nitrogen pipe, gas pipe is equipped with burner quick cut valve and burner regulating valve, nitrogen pipe is connected with nitrogen branch pipe one and nitrogen branch pipe two, nitrogen pipe is equipped with nitrogen total valve, nitrogen branch pipe one and nitrogen branch pipe two are all communicated with gas pipe, burner quick cut valve and burner regulating valve are located between nitrogen branch pipe one and nitrogen branch pipe two, nitrogen branch pipe one is equipped with valve front purging valve, nitrogen branch pipe two is equipped with valve rear purging valve, gas pipe is equipped with combustible gas probe, combustible gas probe is located nitrogen branch pipe two far from burner regulating valve side. Through valve front and valve rear purging, effectively reduce explosion risk, higher security, exclude air interference, make gas fully burn, guarantee combustion stability, combustible gas probe real-time monitoring, provide double protection for system safety, each valve works cooperatively, easy to operate, it is easy to maintain and manage.

Description

Technical Field

[0001] This utility model relates to the field of boiler pipeline technology, specifically to a nitrogen-filling system for boiler gas pipelines. Background Technology

[0002] A boiler is a device that uses the heat energy released by the combustion of fuel or other heat energy to heat the working medium, usually water, to a certain temperature. It is widely used in industrial production, district heating, and power generation. Although different types of boilers have different structures and operating methods, their basic working principles are similar. They mainly achieve energy conversion and utilization through three processes: "fuel combustion to release heat", "heat transfer", and "change in the state of the working medium to produce steam or hot water".

[0003] When the boiler experiences the following abnormal conditions that severely affect operation: water level deviates significantly from the normal range, resulting in water shortage or overfilling; pressure rises sharply and exceeds the safety threshold, and the safety valve fails to activate; heating surface tubes burst, causing a large leakage of steam and water; combustion suddenly goes out or deflagration occurs; and critical auxiliary equipment such as induced draft fans and feedwater pumps malfunction, an emergency shutdown must be implemented to prevent major accidents. After an emergency shutdown of the boiler, a brief backfire may occur in the gas pipeline in front of the boiler, causing the gas in the pipeline from the quick-cut valve to the burner section to ignite. Therefore, it is necessary to extinguish the fire by introducing inert nitrogen gas.

[0004] The current method of introducing nitrogen gas involves manually opening a nitrogen valve to extinguish the fire. However, manually opening and closing the nitrogen valve does not guarantee safety. During this process, there is no precise control over the introduced nitrogen gas, which may result in incomplete fire extinguishing or waste of nitrogen. In severe cases, it may even lead to gas fire and explosion inside the pipeline. Utility Model Content

[0005] The purpose of this utility model is to provide a nitrogen-filling system for boiler gas pipelines, which solves the problem that the existing method of introducing nitrogen gas to extinguish fires is to manually open the nitrogen valve. However, the nitrogen introduced in this process is not precisely controlled, which may result in incomplete fire extinguishing or nitrogen waste. In severe cases, it may even lead to gas fire and explosion accidents in the pipeline.

[0006] To achieve the above objectives, the basic solution provided by this utility model is as follows: a nitrogen charging system for boiler gas pipelines, including a gas pipeline and a nitrogen pipeline. The gas pipeline is equipped with a burner quick-cut valve and a burner regulating valve. The nitrogen pipeline is connected to a nitrogen branch pipe one and a nitrogen branch pipe two. The nitrogen pipeline is equipped with a nitrogen main valve. Both nitrogen branch pipe one and nitrogen branch pipe two are connected to the gas pipeline. The burner quick-cut valve and the burner regulating valve are located between nitrogen branch pipe one and nitrogen branch pipe two. Nitrogen branch pipe one is equipped with a pre-valve purge valve, and nitrogen branch pipe two is equipped with a post-valve purge valve. The gas pipeline is equipped with a combustible gas probe, which is located on the side of nitrogen branch pipe two away from the burner regulating valve.

[0007] The working principle of this utility model is as follows: When the burner quick-cut valve is activated, the nitrogen main valve is opened, and nitrogen flows into nitrogen branch pipe one and nitrogen branch pipe two through the nitrogen pipe. At this time, the pre-valve purging valve is opened, and nitrogen purges the gas pipe before the burner quick-cut valve through nitrogen branch pipe one to remove residual air in the pipe and prevent combustible gas from mixing with air to form an explosive mixture. When the burner is working, the burner regulating valve adjusts the gas flow rate, and the burner quick-cut valve controls the rapid cut-off of the gas. After the operation is completed, the post-valve purging valve is opened, and nitrogen purges the gas pipe after the burner quick-cut valve through nitrogen branch pipe two to blow away the remaining gas. The combustible gas probe monitors the gas concentration in the gas pipe in real time, and promptly sends a feedback signal if the concentration is abnormal.

[0008] The beneficial effects of this utility model are as follows: by purging before and after the valve, the risk of explosion is effectively reduced, the safety is high, air interference is eliminated, the gas is fully combusted, the combustion is stable, the combustible gas probe monitors in real time, providing double protection for system safety, the valves work together, the operation is simple, and the maintenance and management are convenient.

[0009] Option 2, a preferred option of the basic scheme, includes a pre-purge valve comprising a manual pre-purge valve and a pre-purge regulating valve. The manual pre-purge valve is located on the side of the pre-purge regulating valve furthest from the gas pipeline. This combination of a manual pre-purge valve and a regulating valve facilitates manual opening and closing to control nitrogen flow, while also allowing for precise adjustment of the nitrogen flow rate using the regulating valve. Simultaneously, it ensures operational safety, avoiding potential dangers arising from operation near the gas pipeline.

[0010] Option 3, the preferred option of the basic scheme, includes a post-valve purge valve comprising a manual post-valve purge valve and a post-valve purge regulating valve. The manual post-valve purge valve is located on the side of the post-valve purge regulating valve furthest from the gas pipeline. This combination of a manual post-valve purge valve and a regulating valve facilitates manual opening and closing to control nitrogen flow, while also allowing for precise regulation of the nitrogen flow rate using the regulating valve. Simultaneously, it ensures operational safety, avoiding potential dangers arising from operation near the gas pipeline.

[0011] Option 4, the preferred option of the basic scheme, involves installing a pressure gauge on the gas pipe, located on the side of the combustible gas probe furthest from the nitrogen branch pipe 2. This allows for real-time monitoring of the gas pressure within the pipeline, providing intuitive data for system operation, facilitating timely detection of pressure anomalies, preventing safety accidents caused by pressure issues, and also providing a basis for equipment maintenance and parameter adjustments.

[0012] Option 5, an optimal choice from Option 4, involves installing a temperature gauge on the gas pipe, positioned on the side of the pressure gauge furthest from the combustible gas probe. This allows for real-time monitoring of the gas temperature, timely detection of anomalies, prevention of safety hazards, and assistance in system operation control and equipment maintenance, ensuring the stability and safety of the gas system.

[0013] Option 6, an optimized version of Option 5, involves interlocking the burner quick-cut valve, burner regulating valve, nitrogen main valve, pre-purge regulating valve, post-purge regulating valve, combustible gas probe, pressure gauge, and temperature gauge with the DCS control system. This enables remote automated monitoring and precise control, timely response to parameter anomalies, and automatic execution of safety strategies, significantly improving the safety, stability, and efficiency of the nitrogen filling system in the gas pipeline. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of a nitrogen-filling system for a boiler gas pipeline according to this utility model. Detailed Implementation

[0015] The present invention will be further described in detail below through specific embodiments:

[0016] The reference numerals in the accompanying drawings of this instruction manual include: 1. Gas pipe, 2. Nitrogen pipe, 201. Nitrogen branch pipe one, 202. Nitrogen branch pipe two, 3. Burner quick-cut valve, 4. Burner regulating valve, 5. Nitrogen main valve, 6. Pre-valve purge valve, 601. Pre-valve purge manual valve, 602. Pre-valve purge regulating valve, 7. Post-valve purge valve, 701. Post-valve purge manual valve, 702. Post-valve purge regulating valve, 8. Combustible gas probe, 9. Pressure gauge, 10. Temperature gauge.

[0017] Example

[0018] The basic implementation examples are as follows: Figure 1The following describes a nitrogen-filled boiler gas pipeline system: a gas pipeline 1 and a nitrogen pipeline 2. The gas pipeline 1 is equipped with a burner quick-cut valve 3 and a burner regulating valve 4. The nitrogen pipeline 2 is connected to a nitrogen branch pipe 1 201 and a nitrogen branch pipe 202. A nitrogen main valve 5 is installed on the nitrogen pipeline 2. Both nitrogen branch pipes 1 and 202 are connected to the gas pipeline 1. The burner quick-cut valve 3 and the burner regulating valve 4 are located between nitrogen branch pipes 1 and 202. A pre-valve purge valve 6 is installed on nitrogen branch pipe 1 201, which includes a pre-valve purge manual valve 601 and a pre-valve purge regulating valve 602. The pre-valve purge manual valve 601 is located on the side of the pre-valve purge regulating valve 602 away from the gas pipeline 1. A post-valve purge valve 7 is installed on nitrogen branch pipe 202. The purging valve 7 includes a post-purge manual valve 701 and a post-purge regulating valve 702. The post-purge manual valve 701 is located on the side of the post-purge regulating valve 702 away from the gas pipe 1. A combustible gas probe 8 is installed on the gas pipe 1, located on the side of the nitrogen branch pipe 202 away from the burner regulating valve 4. A pressure gauge 9 is installed on the gas pipe 1, located on the side of the combustible gas probe 8 away from the nitrogen branch pipe 202. A temperature gauge 10 is installed on the gas pipe 1, located on the side of the pressure gauge 9 away from the combustible gas probe 8. The burner quick-cut valve 3, burner regulating valve 4, nitrogen main valve 5, pre-purge regulating valve 602, post-purge regulating valve 702, combustible gas probe 8, pressure gauge 9, and temperature gauge 10 are all interlocked with the DCS control system.

[0019] The implementation method of this embodiment is as follows:

[0020] Before starting the nitrogen charging system for the boiler gas pipeline, the operator opens the main nitrogen valve 5 through the DCS control system. Nitrogen flows into nitrogen branch pipe 1 201 and nitrogen branch pipe 2 202 through nitrogen pipe 2. At the same time, the manual purging valve 601 and the purging regulating valve 602 are opened. Nitrogen purges the gas pipe 1 before the burner quick-cut valve 3 through nitrogen branch pipe 1 201 to remove residual air in the pipe. After purging is completed, the purging valve 6 is closed.

[0021] When the system starts up, the operator adjusts the burner regulating valve 4 through the DCS control system to control the gas flow. At the same time, the burner quick-cut valve 3 is opened to allow gas to enter the burner. At this time, the DCS control system receives data from the combustible gas probe 8, pressure gauge 9, and temperature gauge 10 in real time, monitoring the gas concentration, pressure, and temperature in the gas pipe 1. If the parameters are normal, the system continues to operate stably. If the combustible gas probe 8 detects an abnormal gas concentration, or if the pressure gauge 9 or temperature gauge 10 detects that the pressure or temperature exceeds the normal range, the DCS control system will respond immediately, issue an alarm to the operator, and automatically close the burner quick-cut valve 3 to cut off the gas supply. At the same time, the system will adjust the pre-valve purging regulating valve 602 and the post-valve purging regulating valve 702 as needed, using nitrogen to purge the gas pipe 1 to ensure system safety.

[0022] When the system stops running, first close the burner regulating valve 4 and the burner quick-cut valve 3, then open the post-valve purge manual valve 701 and the post-valve purge regulating valve 702. Nitrogen gas is used to purge the gas pipe 1 after the burner quick-cut valve 3 through the nitrogen branch pipe 202 to purge away the remaining gas gas. After the purging is completed, close the post-valve purge valve 7 and the nitrogen main valve 5.

[0023] The above descriptions are merely embodiments of this utility model, and common knowledge regarding specific structures and characteristics is not elaborated upon here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the structure of this utility model, and these should also be considered within the scope of protection of this utility model. These modifications will not affect the effectiveness of the implementation of this utility model or the practicality of the patent. The scope of protection claimed in this application shall be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A nitrogen-filling system for boiler gas pipelines, characterized in that, The system includes a gas pipe (1) and a nitrogen pipe (2). The gas pipe (1) is equipped with a burner quick-cut valve (3) and a burner regulating valve (4). The nitrogen pipe (2) is connected to a nitrogen branch pipe one (201) and a nitrogen branch pipe two (202). The nitrogen pipe (2) is equipped with a nitrogen main valve (5). The nitrogen branch pipe one (201) and the nitrogen branch pipe two (202) are both connected to the gas pipe (1). The burner quick-cut valve (3) and the burner regulating valve (4) are located between the nitrogen branch pipe one (201) and the nitrogen branch pipe two (202). The nitrogen branch pipe one (201) is equipped with a pre-valve purge valve (6). The nitrogen branch pipe two (202) is equipped with a post-valve purge valve (7). The gas pipe (1) is equipped with a combustible gas probe (8). The combustible gas probe (8) is located on the side of the nitrogen branch pipe two (202) away from the burner regulating valve (4).

2. A nitrogen-filling system for boiler gas pipelines according to claim 1, characterized in that, The pre-valve purge valve (6) includes a pre-valve purge manual valve (601) and a pre-valve purge regulating valve (602), wherein the pre-valve purge manual valve (601) is located on the side of the pre-valve purge regulating valve (602) away from the gas pipe (1).

3. A nitrogen-filling system for boiler gas pipelines according to claim 1, characterized in that, The post-valve purge valve (7) includes a post-valve purge manual valve (701) and a post-valve purge regulating valve (702). The post-valve purge manual valve (701) is located on the side of the post-valve purge regulating valve (702) away from the gas pipe (1).

4. A nitrogen-filling system for boiler gas pipelines according to claim 1, characterized in that, A pressure gauge (9) is provided on the gas pipe (1), and the pressure gauge (9) is located on the side of the combustible gas probe (8) away from the nitrogen branch pipe (202).

5. A nitrogen-filling system for boiler gas pipelines according to claim 4, characterized in that, A thermometer (10) is provided on the gas pipe (1), and the thermometer (10) is located on the side of the pressure gauge (9) away from the combustible gas probe (8).

6. A nitrogen-filling system for boiler gas pipelines according to claim 5, characterized in that, The burner quick-cut valve (3), burner regulating valve (4), nitrogen main valve (5), pre-valve purge regulating valve (602), post-valve purge regulating valve (702), combustible gas probe (8), pressure gauge (9) and temperature gauge (10) are all interlocked with the DCS control system.

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