A device and method for online monitoring of calorific value of pulverized coal

Abstract

The present invention discloses a device for online monitoring of the calorific value of pulverized coal and a monitoring method thereof. The device comprises a monitoring pipeline connected to a pulverized coal pipeline, on which an opening and closing valve, an igniter and a combustion chamber are sequentially arranged from the inside to the outside, a temperature measuring point located at the combustion chamber is arranged on the monitoring pipeline, and the outer end of the monitoring pipeline is open. The monitoring method comprises the following steps: opening the opening and closing valve, charging the positive pressure pulverized coal in the pulverized coal pipeline into the monitoring pipeline, igniting the positive pressure pulverized coal with an igniter, and burning the positive pressure pulverized coal in the combustion chamber, forming a temperature field at the combustion chamber, and obtaining the temperature value of the temperature field by the temperature measuring point. After the temperature value is obtained, the opening and closing valve is closed, and the calorific value of the pulverized coal is analyzed by using the temperature field value obtained by the temperature measuring point. The beneficial effects of the present invention: solve the technical problem that the pulverized coal cannot be monitored in real time in the current industry, and have technical guiding significance for pulverized coal furnaces, especially for large units with unstable coal quality, and have great application value.

Description

Technical Field

[0001] The invention belongs to the technical field of power plants, and in particular relates to a device for online monitoring of calorific value of pulverized coal and a monitoring method thereof. Background Art

[0002] In power plant systems, real-time monitoring of the calorific value of coal powder in boilers has always been a difficult problem. At present, power plants often take samples of coal powder and then analyze it in the laboratory to complete the analysis and testing of the calorific value of coal powder. The process of analyzing the calorific value requires first taking samples of coal powder and then analyzing it in the laboratory, which usually takes about 2 hours. The hysteresis is extremely poor, which is not conducive to monitoring the calorific value of coal powder and guiding the adjustment of steam boilers. For units with unstable coal quality, such as mixed-burning units, especially units with lax supervision of foreign coal ships, the coal quality varies greatly, the calorific value is not stable, and there is a certain hysteresis, which will be unfavorable for guiding actual operation and adjustment, and is not conducive to the economy of the boiler.

[0003] At present, there are invention patents for online monitoring through spectroscopy, microwave and other analytical methods, but they are expensive and have limited practicality. They have not been put into use in power plants at home and abroad, which has always restricted the real-time analysis of the calorific value of coal powder.

[0004] When analyzing coal powder in the laboratory, in addition to the calorific value of coal powder, there is also composition analysis. However, in terms of directly and effectively guiding operation, the purpose of the sampling device can be achieved if the calorific value information of coal powder can be obtained instantly. However, both in the market and in domestic and foreign power plants, they are generally restricted by the real-time nature of coal powder calorific value analysis. Summary of the invention

[0005] The purpose of the present invention is to provide a device for online monitoring of the calorific value of pulverized coal and a monitoring method thereof, which solves the technical problem that the calorific value of pulverized coal cannot be monitored online in real time.

[0006] The object of the present invention is achieved through the following technical solutions:

[0007] A device for online monitoring of calorific value of pulverized coal includes a monitoring pipeline connected to a pulverized coal pipeline, an on-off valve, an igniter, and a combustion chamber are sequentially arranged on the monitoring pipeline from the inside to the outside, a temperature measuring point is arranged on the monitoring pipeline at the combustion chamber, and the outer end of the monitoring pipeline is an open port connected to the combustion chamber. The on-off valve is used to control the on-off of the monitoring pipeline and the pulverized coal pipeline, the igniter is used to ignite the pulverized coal, the combustion chamber is used for the pulverized coal to burn, and the temperature measuring point detects the temperature field formed by the combustion of the pulverized coal.

[0008] Furthermore, the monitoring pipeline is L-shaped, one end of the monitoring pipeline is arranged horizontally and connected to the vertical pulverized coal pipeline, and the other end of the monitoring pipeline is arranged vertically and faces upward, so that the positive pressure pulverized coal in the vertical pulverized coal pipeline is passed into the vertical section through the horizontal section and burned upward in the vertical section.

[0009] Furthermore, the monitoring pipeline is L-shaped, the on-off valve is located at one end of the monitoring pipeline, the igniter is located at the corner of the monitoring pipeline, and the combustion chamber is located at the other end of the monitoring pipeline. The layout of each component is reasonable, the overall structure volume is reduced, and the normal and stable combustion monitoring can be ensured.

[0010] Furthermore, the on-off valve is a quick-opening pneumatic valve to achieve rapid opening and closing of the pipeline.

[0011] Furthermore, the monitoring pipeline is connected to the gas source pipe, a shut-off valve is provided on the gas source pipe, and the gas source pipe is connected to the purge gas and the combustion-supporting gas respectively. The purge gas is used to purge the pipeline, and the combustion-supporting gas is used to support the combustion of the pulverized coal.

[0012] Furthermore, the gas source pipe is directed toward the combustion chamber, so that the purging and combustion-supporting can be directed toward the combustion chamber, and the effect is direct.

[0013] Furthermore, the purge gas is compressed air, and the combustion-supporting gas is natural gas.

[0014] Furthermore, the temperature measuring points are provided with at least one layer, and each layer of temperature measuring points is arranged circumferentially on the outside of the combustion chamber to achieve uniform temperature detection of the entire outer wall of the temperature field.

[0015] Furthermore, the monitoring pipeline is provided with a cooling component located at the combustion chamber. The type of the cooling component is not limited, and rapid cooling of the combustion chamber can be achieved.

[0016] Furthermore, the cooling component is a cooling water tank, the upper end of the cooling water tank is provided with a water inlet pipe, and the lower end of the cooling water tank is provided with a drain valve.

[0017] A monitoring method for the above-mentioned device for online monitoring of the calorific value of pulverized coal includes the following steps: opening an on-off valve, charging the positive-pressure pulverized coal in the pulverized coal pipeline into a monitoring pipeline, igniting the positive-pressure pulverized coal with an igniter, and burning the positive-pressure pulverized coal in a combustion chamber to form a temperature field in the combustion chamber. The temperature value of the temperature field is obtained by a temperature measuring point. After the temperature value is obtained, closing the on-off valve, and analyzing the calorific value of the pulverized coal using the temperature field value obtained by the temperature measuring point.

[0018] Furthermore, after the combustion is completed, purge gas is filled into the monitoring pipeline to clean the remaining coal powder.

[0019] Furthermore, during combustion, combustion-supporting gas is charged into the monitoring pipeline to assist the positive-pressure coal powder in combustion.

[0020] The beneficial effects of the present invention are as follows: the technical difficulty of being unable to monitor coal powder in real time in the current industry is solved, and it has technical guiding significance for coal powder furnaces, especially for large units with unstable coal quality, and has great application value.

[0021] The aforementioned main scheme of the present invention and its further options can be freely combined to form multiple schemes, all of which are schemes that can be adopted and claimed for protection by the present invention; and in the present invention, (non-conflicting options) options and other options can also be freely combined. After understanding the scheme of the present invention, those skilled in the art can understand that there are many combinations based on the prior art and common knowledge, all of which are technical schemes to be protected by the present invention, and they are not exhaustively listed here. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of the present invention.

[0023] In the figure: 1 is the pulverized coal pipeline; 2 is the opening and closing valve; 3 is the gas source pipe; 4 is the shut-off valve; 5 is the temperature measuring point; 6 is the drain valve; 7 is the cooling water tank; 8 is the combustion chamber; 9 is the water inlet pipe; and 10 is the igniter. DETAILED DESCRIPTION

[0024] The following non-limiting examples serve to illustrate the invention.

[0025] Embodiment 1:

[0026] refer to Figure 1 As shown, a device for online monitoring of the calorific value of pulverized coal includes a pulverized coal pipeline 1, a monitoring pipeline, an on-off valve 2, a gas source pipe 3, a shut-off valve 4, a temperature measuring point 5, a cooling component, a combustion chamber 8 and an igniter 10.

[0027] The pulverized coal pipeline 1 is arranged vertically. After the coal mill grinds the coal into powder, it passes through the pulverized coal pipeline, and there is a positive pressure of pulverized coal above 1 kPa in the pulverized coal pipeline. The monitoring pipeline is L-shaped, one end of the monitoring pipeline is arranged horizontally and connected to the vertical pulverized coal pipeline 1, and the other end of the monitoring pipeline is arranged vertically and upward.

[0028] The monitoring pipeline is provided with an opening and closing valve 2, an igniter 10 and a combustion chamber 8 in sequence from the inside to the outside, and the outer end of the monitoring pipeline is an open port connected to the combustion chamber 8.

[0029] The on-off valve 2 is a quick-opening pneumatic valve located in the horizontal section of the monitoring pipeline and is used to control the connection between the monitoring pipeline and the coal powder pipeline. The igniter 10 is located outside the corner of the monitoring pipeline and is used to ignite the coal powder for combustion. The combustion chamber 8 is located in the vertical section of the monitoring pipeline and is used to provide space for the coal powder to burn. The opening at the outer end of the monitoring pipeline provides oxygen to the combustion chamber.

[0030] The monitoring pipeline is provided with temperature measuring points 5 located at the combustion chamber 8. There is at least one layer of temperature measuring points 5, and each layer of temperature measuring points 5 is arranged circumferentially outside the combustion chamber 8. The temperature measuring points can use temperature sensors to monitor the temperature value of the temperature field formed by the combustion of coal powder.

[0031] The horizontal section of the monitoring pipeline is connected to the gas source pipe 3, and the gas source pipe 3 faces the combustion chamber 8 to ensure better cleaning and combustion-supporting effects. A shut-off valve 4 is provided on the gas source pipe 3, and the shut-off valve is used to control the connection between the external gas source and the monitoring pipeline. The gas source pipe 3 is connected to the cleaning gas and the combustion-supporting gas respectively. The cleaning gas is compressed air, and the residual coal powder is purged by high-pressure air. The combustion-supporting gas is natural gas, which assists the combustion of coal powder, helps the coal powder burn faster and better, and improves the combustion efficiency.

[0032] The monitoring pipeline is provided with a cooling component located at the combustion chamber 8. The cooling component is a ring-mounted cooling water tank 7, the upper end of which is provided with a water inlet pipe 9, and the lower end of which is provided with a drain valve 6. The cooling water in the cooling water tank absorbs heat from the outer wall of the combustion chamber, so that the combustion chamber is cooled quickly.

[0033] Embodiment 2:

[0034] refer to Figure 1 As shown, a monitoring method for the above-mentioned device for online monitoring of the calorific value of pulverized coal includes the following steps: opening the on-off valve 2, charging the positive-pressure pulverized coal in the pulverized coal pipeline 1 into the monitoring pipeline, igniting the positive-pressure pulverized coal with the igniter 10, and burning the positive-pressure pulverized coal in the combustion chamber 8 to form a temperature field in the combustion chamber 8. The temperature value of the temperature field is obtained by the temperature measuring point 5. After the temperature value is obtained, generally after 3s, the on-off valve 2 is closed, and the calorific value of the pulverized coal is analyzed using the temperature field value obtained by the temperature measuring point.

[0035] After the combustion is completed, the cleaning gas is filled into the monitoring pipeline to clean the residual coal powder. During the combustion, the auxiliary gas is filled into the monitoring pipeline to assist the positive pressure coal powder to burn.

[0036] The key point of this method is to obtain the corresponding relationship between the temperature field and the calorific value of coal powder. The temperature field formed by the coal powder at the same time in the combustion chamber is different due to the different calorific values ​​of coal powder. After each combustion of coal powder, the size of the temperature field data can be used to directly determine the size of the calorific value of coal powder. At the same time, when making the curve corresponding to the calorific value of coal powder and the temperature field, this method must ensure timing and quantification, so as to ensure that the amount of coal powder / combustion-supporting gas sent into the combustion chamber at the same time is the same, so as to obtain an accurate calorific value of coal powder.

[0037] The aforementioned basic examples of the present invention and their further selected examples can be freely combined to form multiple embodiments, all of which are embodiments that can be adopted and claimed for protection by the present invention. In the scheme of the present invention, each selected example can be arbitrarily combined with any other basic example and selected example. For example, as shown in FIG. , it can also be regarded as a combination of a basic example and a selected example . . . , and FIG. . . can also be regarded as a combination of a basic example and a selected example . . . , and so on. This is not exhaustive, and those skilled in the art will know that there are many combinations.

[0038] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A device for online monitoring of calorific value of pulverized coal, comprising a monitoring pipeline connected to a pulverized coal pipeline (1), characterized in that: The monitoring pipe is provided with an opening and closing valve (2), an igniter (10) and a combustion chamber (8) in order from the inside to the outside, the monitoring pipe is provided with a temperature measuring point (5) located at the combustion chamber (8), and the outer end of the monitoring pipe is an open port connected to the combustion chamber (8); The monitoring pipeline is L-shaped, one end of the monitoring pipeline is arranged horizontally and connected to the vertical pulverized coal pipeline (1), and the other end of the monitoring pipeline is arranged vertically and faces upward; The monitoring pipeline is L-shaped, the on-off valve (2) is located at one end of the monitoring pipeline, the igniter (10) is located at a corner of the monitoring pipeline, and the combustion chamber (8) is located at the other end of the monitoring pipeline; The monitoring pipeline is connected to a gas source pipe (3), a shut-off valve (4) is provided on the gas source pipe (3), and the gas source pipe (3) is connected to the purge gas and the combustion-supporting gas respectively; The gas source pipe (3) faces the combustion chamber (8); The temperature measuring points (5) are provided with at least one layer, and each layer of temperature measuring points (5) is arranged circumferentially on the outside of the combustion chamber (8); The monitoring pipeline is provided with a cooling component located at the combustion chamber (8).

2. A monitoring method for the device for online monitoring of calorific value of pulverized coal according to claim 1, characterized in that: The method comprises the following steps: opening an on-off valve (2), charging the positive-pressure coal powder in the coal powder pipeline (1) into a monitoring pipeline, igniting the positive-pressure coal powder with an igniter (10), and burning the positive-pressure coal powder in a combustion chamber (8), thereby forming a temperature field in the combustion chamber (8); obtaining a temperature value of the temperature field by a temperature measuring point (5); and after the temperature value is obtained, closing the on-off valve (2); and analyzing the calorific value of the coal powder using the temperature field value obtained by the temperature measuring point.

3. The monitoring method according to claim 2, characterized in that: After the combustion is completed, the cleaning gas is filled into the monitoring pipeline to clean the residual coal powder.

4. The monitoring method according to claim 2 or 3, characterized in that: During combustion, combustion-supporting gas is filled into the monitoring pipeline to assist the positive pressure coal powder to burn.

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