Infrared imaging system and testing method for flow field in boiler furnace

Abstract

The infrared imaging system and test method of the flow field in the boiler furnace include opening a hole at the entrance of the boiler air duct to set up a flue gas heating device, and an infrared imaging camera is set on the boiler. The infrared imaging camera is used to shoot infrared temperature imaging in the furnace in real time. The output end of the infrared imaging camera is connected to a streaming media server through a network, and the output end of the streaming media server is connected to a user terminal. The present invention utilizes the temperature difference between the hot air and the boiler furnace, sets up an infrared thermal imaging camera at a reasonable position on the boiler furnace, uses the infrared thermal imaging principle to record the flow process of the hot air in the furnace in real time, and uses 5G or high-speed wired network to achieve real-time data transmission and storage.

Description

Technical Field

[0001] The invention relates to the technical field of measuring flow fields in industrial boilers and power station boilers, and in particular to an infrared imaging system and a testing method for flow fields in boilers. Background Art

[0002] The boiler needs to burn fuel in a certain combustion space. The boiler effectively mixes the fuel and the combustion aid (air) through the burner to make the fuel burn fully and reduce the generation of pollutants. Since the boiler is equipped with multiple and multi-layer burners, each layer of burners adopts different combustion methods such as four-corner cutting circle, front and rear wall hedging, and octagonal double cutting circle. Therefore, each burner needs to be able to meet the effective combustion of fuel and combustion aid, and at the same time, it is also necessary to meet the requirements of a single burner entering the furnace The flow field is uniform and stable, and the entire furnace flow field is also uniform and fully burned.

[0003] To achieve this requirement, it is generally necessary to adjust the air duct resistance of each layer of burners and in front of the burners so that the air volume of each layer of burners is basically the same, and pass the cold test inspection.

[0004] The traditional cold test is to install fireworks near the burner, ignite the fireworks, and then judge the burner air distribution and the flow field distribution in the furnace by observing the trajectory of the fireworks. This method has the following disadvantages:

[0005] (1) Fireworks need to be reinstalled for each test;

[0006] (2) Fireworks are ejected over a short time, so long-term observation is not possible;

[0007] High cost and complicated operation (such as Figure 4 shown). Summary of the invention

[0008] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide an infrared imaging system and a testing method for the flow field in a boiler furnace. The system utilizes the temperature difference between the hot air and the boiler furnace, and sets up an infrared thermal imaging camera at a reasonable position on the boiler furnace. The infrared thermal imaging principle is used to record the flow process of the hot air in the furnace in real time, and 5G or high-speed wired networks are used to realize real-time data transmission and storage.

[0009] In order to achieve the above object, the technical solution adopted by the present invention is:

[0010] The infrared imaging system of the flow field in a boiler furnace includes a flue gas heating device 1 set up at a hole at the entrance of the boiler air duct, an infrared imaging camera 2 is arranged on the boiler, and the infrared imaging camera 2 is used to take infrared temperature imaging of the furnace in real time. The output end of the infrared imaging camera 2 is connected to a streaming media server 5 through a network, and the output end of the streaming media server 5 is connected to a user terminal 6.

[0011] The flue gas heating device 1 is hot steam or an electric heating wire.

[0012] The infrared imaging camera 2 is arranged at the rope hole 3 on the furnace roof, the entrance door 4 on the upper part of the furnace, or is carried by an unmanned aerial vehicle.

[0013] The outer dimension of the unmanned aerial vehicle is smaller than the diameter of the entry door 4 .

[0014] The network is classified into 5G or a high-speed wired network.

[0015] A method for testing a boiler furnace flow field infrared imaging system comprises the following steps:

[0016] Step 1:

[0017] Determine the maximum electric power and maximum steam flow of the heating device according to the maximum air volume designed for the burner;

[0018] The maximum electric power calculation formula is:

[0019] W Max =1.05Q Max (C t+10 -C t )

[0020] Among them, W Max —The maximum electrical power required by the heating device, kW;

[0021] Q Max —The maximum air volume designed for the burner, m 3 / s;

[0022] C t ,C t+10 —Specific heat of air at t℃ and t+10℃, kJ / m 3 ;

[0023] t—The temperature of air before heating, which can be 30℃.

[0024] Using steam as heat source, the maximum steam flow calculation formula is:

[0025] q Max ≈W Max / C steam

[0026] Among them, q Max —Maximum steam flow rate, kg / s;

[0027] C steam —Specific heat of steam, kJ / kg.

[0028] The specific heat of steam is obtained by looking up the temperature-enthalpy table based on the temperature and pressure of the steam source;

[0029] Determine the installation position of the infrared thermal imaging camera 2 or the deployment of the unmanned aerial vehicle according to the actual situation in the furnace, and deploy the network system. The outer size of the unmanned aerial vehicle is smaller than the diameter of the entry door 450mm;

[0030] Step 2: System installation;

[0031] (1) Install a flue gas heating device 1 in the air duct opening;

[0032] (2) Install an infrared imaging camera 2 on the top of the boiler or deploy an unmanned aerial vehicle;

[0033] (3) deploying a network between the infrared imaging camera 2 and the streaming media server 5;

[0034] Step 3: Debug;

[0035] (1) Start the boiler blower and adjust the air flow of the burner duct to the designed maximum air volume;

[0036] (2) starting the flue gas heating device 1 to the designed maximum power;

[0037] (3) The infrared imaging camera 2 records for more than 4 minutes from the start of the flue gas heating device 1 through the network;

[0038] (4) Check the infrared thermal imaging results, check whether the heating power, infrared imaging camera 2, and network communication are normal, and adjust the infrared imaging system to meet the test conditions;

[0039] Step 4: Test;

[0040] (1) Adjust the air volume of the burner according to the test requirements;

[0041] (2) Adjust the flue gas heating device 1 to the maximum power and maintain it for more than 6 minutes;

[0042] (3) infrared thermal imaging by infrared imaging camera 2;

[0043] (4) Check and store imaging files;

[0044] Step 5: Analyze infrared thermal imaging results;

[0045] Analyze infrared thermal imaging images to determine whether the burner air supply is skewed and whether the flow field in the furnace is uniform and stable. If there is a problem, engineers can adjust the burner and air supply system.

[0046] The control requirements of the infrared imaging camera 2 are as follows:

[0047] a: The air temperature entering the furnace should be higher than the ambient temperature inside the furnace, and the minimum temperature difference should be greater than 10°C;

[0048] b: Choose an environment without sunlight or at night. Under sunlight, the reflection and diffuse reflection of light will greatly interfere with the infrared radiation waves of the infrared imaging camera 2. Without the insertion of other light, the device under test can measure a stable temperature.

[0049] C: Choose a dust-free environment. Dust and suspended particles in the air will cause infrared radiation to attenuate during transmission. Therefore, accurate measurement can only be guaranteed in a dust-free environment.

[0050] Beneficial effects of the present invention:

[0051] The present invention can conveniently and quickly complete the test of burner air distribution and uniform and stable flow field in the furnace, and can verify the adjusted burner and air supply system at any time, and the test results of infrared thermal imaging can be digitally stored. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 It is a schematic diagram of the structure of the electric heating source of the present invention.

[0053] Figure 2 It is a schematic diagram of the steam heat source structure of the present invention.

[0054] Figure 3 This is a schematic diagram of the structure of the infrared imaging camera of the present invention.

[0055] Figure 4 This is a schematic diagram of traditional test results.

[0056] Figure 5 It is a transverse cross-sectional view of the present invention.

[0057] Figure 6 It is a schematic diagram of the network flow of the present invention.

[0058] Figure 7 It is a schematic diagram of infrared imaging of the present invention. DETAILED DESCRIPTION

[0059] The present invention is further described in detail below in conjunction with embodiments.

[0060] like Figure 1 Figure 2 As shown: a hole is opened in the air duct in front of the burner, and a heat source is set up at the hole. The specific heat sources are the following two: electric heat source and steam heat source.

[0061] like Figure 3 As shown:

[0062] The infrared thermal imaging camera 2 must meet the following requirements for accurate measurement of the flow field in the furnace:

[0063] a. The temperature of the air entering the furnace should be higher than the ambient temperature inside the furnace. The minimum temperature difference should be greater than 10°C.

[0064] b. Choose an environment without sunlight or at night. Under sunlight, the reflection and diffuse reflection of light will greatly interfere with the infrared radiation waves of the infrared thermal imaging camera. Without the insertion of other light, the device under test can measure a stable temperature.

[0065] c. Choose a dust-free environment. Dust and suspended particles in the air will cause infrared radiation to attenuate during transmission. Therefore, accurate measurements can only be ensured in a dust-free environment.

[0066] The infrared thermal imaging camera 2 is installed at the rope hole on the top of the boiler furnace, the upper entrance door of the furnace, or an infrared thermal imaging camera carried by an unmanned aerial vehicle;

[0067] The infrared thermal imaging camera 2 realizes data transmission and storage through 5G or high-speed wired network.

[0068] The invention can be used for boilers with different combustion modes such as four-corner cutting circle, front and rear wall hedging, and octagonal double cutting circle.

[0069] The present invention sets up a flue gas heating device at the entrance of the boiler air duct, and the heating heat source can be hot steam or electric heating wire (see Figure 1 Figure 2 ).

[0070] An infrared thermal imaging camera or an unmanned aerial vehicle carrying an infrared thermal imaging camera 2 can be installed at the rope hole on the boiler roof or the upper entrance door of the furnace to capture infrared temperature images in the furnace in real time.

[0071] The infrared thermal imaging camera 2 can transmit the captured data to the streaming media server 5 through 5G or a high-speed wired network for analysis and use by the user terminal 6 (see Figure 6 ).

[0072] When conducting a cold test of the flow field in a boiler furnace, the air heated by the air duct in front of one or a layer of burners is sent into the furnace according to the test needs. The air can be heated to a temperature higher than room temperature (hot air 30℃~50℃, temperature difference greater than 10℃). In this way, the hot air is used to simulate the actual operation of the burner air distribution and flow field in the furnace, and the entire process of hot air entering the furnace is recorded in real time through infrared temperature imaging video.

[0073] Example:

[0074] 1. Determine the project implementation plan design according to the specific conditions of the power plant:

[0075] The maximum electric power and maximum steam flow of the heating device are determined according to the maximum air volume designed for the burner.

[0076] The maximum electric power calculation formula is:

[0077] W Max =1.05Q Max (C t+10 -C t )

[0078] Among them, W Max —The maximum electrical power required by the heating device, kW;

[0079] Q Max —The maximum air volume designed for the burner, m 3 / s;

[0080] C t ,C t+10 —Specific heat of air at t℃ and t+10℃, kJ / m 3 ;

[0081] t—The temperature of air before heating, which can be 30℃.

[0082] Using steam as heat source, the maximum steam flow calculation formula is:

[0083] q Max ≈W Max / C steam

[0084] Among them, q Max —Maximum steam flow rate, kg / s;

[0085] C steam —Specific heat of steam, kJ / kg.

[0086] The specific heat of steam is obtained by looking up the temperature-enthalpy table based on the temperature and pressure of the steam source.

[0087] The installation position of the infrared thermal imaging camera or the deployment of the unmanned aerial vehicle is determined according to the actual situation in the furnace, and the network system is deployed. The outer size of the unmanned aerial vehicle is smaller than the diameter of the entrance door 450mm.

[0088] 2. System Installation

[0089] (1) Install a flue gas heating device 1 in the air duct opening;

[0090] (2) Install an infrared imaging camera 2 on the top of the boiler or deploy an unmanned aerial vehicle;

[0091] (3) Deploy the network between the infrared imaging camera 2 and the streaming media server 5. Figure 5 Figure 6 (shown)

[0092] 3. Debugging

[0093] (1) Start the boiler blower and adjust the air flow of the burner duct to the designed maximum air volume;

[0094] (2) starting the flue gas heating device 1 to the designed maximum power;

[0095] (3) The infrared imaging camera 2 records for more than 4 minutes from the start of the flue gas heating device 1 through the network;

[0096] (4) Check the infrared thermal imaging results, check whether the heating power, infrared imaging camera 2, and network communication are normal, and adjust the infrared imaging system to meet the test conditions;

[0097] 4. Experiment

[0098] (5) Adjust the air volume of the burner according to the test requirements;

[0099] (6) Adjust the flue gas heating device 1 to the maximum power and maintain it for more than 6 minutes;

[0100] (7) Simultaneously, infrared imaging camera 2 performs infrared thermal imaging;

[0101] (8) Check and store imaging files.

[0102] 5. Analyze infrared thermal imaging results (such as Figure 7 (shown)

[0103] Analyze infrared thermal imaging images to determine whether the burner air distribution is skewed and whether the flow field in the furnace is uniform and stable. If there is a problem, the engineer can adjust the burner and air supply system, and use the equipment and method of this application to conduct test verification.

[0104] The present invention can be used to conveniently and quickly complete the test of burner air distribution and uniform and stable flow field in the furnace, and the adjusted burner and air supply system can be verified at any time, and the test results of infrared thermal imaging can be digitally stored.

Claims

1. A test method for a boiler furnace flow field infrared imaging system, characterized in that: The steps include: Step 1: Determine the maximum electric power and maximum steam flow of the heating device according to the maximum air volume designed for the burner; The maximum electric power calculation formula is: W Max =1.05Q Max (C t+10 -C t ) Among them, W Max —The maximum electrical power required by the heating device, kW; Q Max —The maximum air volume designed for the burner, m 3 / s; C t ,C t+10 —Specific heat of air at t℃ and t+10℃, kJ / m 3 ; t—30℃； Using steam as heat source, the maximum steam flow calculation formula is: q Max ≈W Max / C steam Among them, q Max —Maximum steam flow rate, kg / s; C steam —Specific heat of steam, kJ / kg; The specific heat of steam is obtained by looking up the temperature-enthalpy table based on the temperature and pressure of the steam source; Determine the installation position of the infrared thermal imaging camera 2 or the deployment of the unmanned aerial vehicle according to the actual situation in the furnace, and deploy the network system. The outer size of the unmanned aerial vehicle is smaller than the diameter of the entry door 450mm; Step 2: System installation; (1) Install a flue gas heating device 1 in the air duct opening; (2) Install an infrared imaging camera 2 on the top of the boiler or deploy an unmanned aerial vehicle; (3) deploying a network between the infrared imaging camera 2 and the streaming media server 5; Step 3: Debug; (1) Start the boiler blower and adjust the air flow of the burner duct to the designed maximum air volume; (2) starting the flue gas heating device 1 to the designed maximum power; (3) The infrared imaging camera 2 records for more than 4 minutes from the start of the flue gas heating device 1 through the network; (4) Check the infrared thermal imaging results, check whether the heating power, infrared imaging camera 2, and network communication are normal, and adjust the infrared imaging system to meet the test conditions; Step 4: Test; (1) Adjust the air volume of the burner according to the test requirements; (2) Adjust the flue gas heating device 1 to the maximum power and maintain it for more than 6 minutes; (3) infrared thermal imaging by infrared imaging camera 2; (4) Check and store imaging files; Step 5: Analyze infrared thermal imaging results; Analyze infrared thermal imaging images to determine whether the burner air supply is skewed and whether the flow field in the furnace is uniform and stable. If there is a problem, the engineering staff can adjust the burner and air supply system; The infrared imaging system for the flow field in a boiler furnace comprises a flue gas heating device (1) installed at a hole at the entrance of a boiler air duct, an infrared imaging camera (2) arranged on the boiler, the infrared imaging camera (2) being used to take infrared temperature images of the furnace in real time, the output end of the infrared imaging camera (2) being connected to a streaming media server (5) via a network, and the output end of the streaming media server (5) being connected to a user terminal (6).

2. The test method of the boiler furnace flow field infrared imaging system according to claim 1 is characterized in that: The flue gas heating device (1) is hot steam or an electric heating wire.

3. The test method of the boiler furnace flow field infrared imaging system according to claim 1 is characterized in that: The infrared imaging camera (2) is arranged at a rope hole (3) on the furnace roof, an entrance door (4) on the upper part of the furnace, or is carried by an unmanned aerial vehicle.

4. The test method of the boiler furnace flow field infrared imaging system according to claim 3 is characterized in that: The outer dimensions of the unmanned aerial vehicle are smaller than the diameter of the entry door (4).

5. The test method of the boiler furnace flow field infrared imaging system according to claim 1 is characterized in that: The network is classified into 5G or a high-speed wired network.

6. The test method of the boiler furnace flow field infrared imaging system according to claim 1 is characterized in that: The control requirements of the infrared imaging camera (2) are as follows: a: The air temperature entering the furnace should be higher than the ambient temperature inside the furnace, and the minimum temperature difference should be greater than 10°C; b: Choose an environment without sunlight or at night. Under sunlight, the reflection and diffuse reflection of light will greatly interfere with the infrared radiation waves of the infrared imaging camera (2). Without the insertion of other light, the device under test can measure a stable temperature. C: Choose a dust-free environment. Dust and suspended particles in the air will cause infrared radiation to attenuate during transmission. Therefore, accurate measurement can only be guaranteed in a dust-free environment.

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