Primary air reheating system for pulverized coal boiler
By setting up a heat exchanger and a cyclone separator in a pulverized coal boiler and heating the primary air with high temperature flue gas, the problem of large energy consumption of heating primary air in the prior art is solved, and the peak shaving capability and environmental friendliness of the thermal power unit are improved.
Patent Information
- Application Number
- CN202420439752.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-06
- Publication Date
- 2025-01-03
- Estimated Expiration
- 2034-03-06
AI Technical Summary
When the prior art improves the peak shaving capacity of thermal power units, the energy consumption is large by heating primary wind, which affects environmental friendliness.
Design a primary air reheating system for pulverized coal boilers. By setting up a heat exchanger, the high-temperature flue gas generated by the boiler is heat exchanged with the primary air, the temperature of the primary air is increased, and the treatment is carried out through a cyclone separator and dust collector. Dust in the flue gas reduces energy consumption and carbon emissions.
It effectively improves the peak-shaving capacity of the boiler and the low-load and stable combustion conditions, reduces power consumption and carbon emissions, and improves environmental friendliness.
Smart Images
Figure CN222297979U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of thermal power generation equipment, and in particular to a primary air reheating system for a pulverized coal boiler. Background Art
[0002] As the installed capacity of new energy power generating units increases year by year, there are higher requirements for the peak-shaving capacity of thermal power plants. However, the peak-shaving capacity of many thermal power units that have been put into operation is weak. In order to improve the peak-shaving capacity of thermal power units, the current main technologies are flexibility transformation technology and low-load stable combustion technology. Increasing the primary air temperature is beneficial to the low-load stable combustion of the boiler. Currently, the primary air is heated mainly by installing heaters and air heaters, but the energy consumption of heating the primary air in this way is relatively high. Utility Model Content
[0003] The present application aims to solve the technical problems in the related technologies at least to a certain extent. To this end, the present application proposes a primary air reheating system for a pulverized coal boiler, which can effectively heat the primary air and reduce energy consumption.
[0004] To achieve the above objectives, the present application discloses a primary air reheating system for a pulverized coal boiler, comprising:
[0005] boiler;
[0006] a heat exchanger connected to the boiler to receive the flue gas generated by the boiler;
[0007] a fan, the fan being connected to the heat exchanger to convey primary air to the heat exchanger, the primary air and the flue gas exchanging heat in the heat exchanger; and
[0008] A coal mill is connected to the boiler and the heat exchanger respectively. The primary air after heat exchange is transported to the coal mill and then mixed with coal powder and transported to the boiler.
[0009] In some embodiments of the present application, the primary air reheating system for a pulverized coal boiler further includes a cyclone separator, the heat exchanger is connected to the boiler via the cyclone separator, and the flue gas is input into the heat exchanger after being processed by the cyclone separator.
[0010] In some embodiments of the present application, the boiler is provided with a flue, and the cyclone separator is connected to the flue of the boiler.
[0011] In some embodiments of the present application, the primary air reheating system for a pulverized coal boiler further includes a dust collector, and the dust collector is connected to the cyclone separator to process dust discharged by the cyclone separator.
[0012] In some embodiments of the present application, the cyclone separator is provided with a first inlet, a first discharge port and a second discharge port, the heat exchanger is provided with a first inlet and a first outlet, the first inlet is connected to the boiler, the first discharge port is connected to the first inlet, and the second discharge port is connected to the dust collector.
[0013] In some embodiments of the present application, the first outlet is connected to the dust collector.
[0014] In some embodiments of the present application, the first outlet and the second outlet are connected to the same dust collector.
[0015] In some embodiments of the present application, the heat exchanger is further provided with a second inlet and a second outlet, the primary air enters the heat exchanger from the second inlet for heat exchange, and is discharged from the second outlet to be transported to the coal mill.
[0016] In some embodiments of the present application, the primary air reheating system for a pulverized coal boiler further includes a dust collector, and the dust collector is connected to the heat exchanger to process the flue gas after heat exchange.
[0017] In some embodiments of the present application, the primary air reheating system for a pulverized coal boiler further includes a smoke exhaust duct, and the smoke exhaust duct is connected to the dust collector.
[0018] In some embodiments of the present application, the heat exchanger is a tubular heat exchanger, the flue gas flows outside the pipe of the tubular heat exchanger, and the primary air flows inside the pipe of the tubular heat exchanger.
[0019] The technical solution of this application sets a heat exchanger to guide the high-temperature flue gas generated by the boiler into the heat exchanger for heat exchange with the primary air, thereby realizing the use of the heat of the high-temperature flue gas to heat the primary air, increase the wind temperature of the primary air, reduce the furnace ignition height and ignition time of the boiler, improve the peak-shaving capacity of the boiler, and provide favorable conditions for the low-load stable combustion of the boiler. Compared with the prior art method of setting a heater to heat the primary air, this application uses the heat of the high-temperature flue gas to heat the primary air, which fully utilizes the heat of the flue gas, reduces power consumption, reduces carbon emissions, and is more environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.
[0021] Figure 1Schematic diagram of a primary air reheating system for a pulverized coal boiler in some embodiments.
[0022] Description of Figure Numbers:
[0023] Boiler 100, flue 110;
[0024] Heat exchanger 200, first inlet 210, first outlet 220, second inlet 230, second outlet 240;
[0025] Cyclone separator 300, first inlet 310, first discharge port 320, second discharge port 330;
[0026] Fan 400;
[0027] Coal mill 500;
[0028] Dust collector 600;
[0029] Smoke exhaust duct 700.
[0030] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION
[0031] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.
[0032] It should be noted that all directional indications in the embodiments of the present application (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.
[0033] In this application, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.
[0034] In addition, in this application, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in this field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.
[0035] In order to achieve heating of primary air and reduce energy consumption, the present application proposes a primary air reheating system for a pulverized coal boiler, and the primary air reheating system for a pulverized coal boiler includes a boiler 100, a heat exchanger 200, a fan 400 and a coal mill 500.
[0036] The boiler 100 is an energy conversion device. When chemical energy is input into the boiler 100, the boiler 100 can output steam, high-temperature water, etc. with a certain amount of heat energy. Taking the steam boiler 100 of thermal power generation as an example, coal is used as fuel. The boiler 100 is provided with a furnace, i.e., a combustion chamber. The coal can be burned in the furnace to generate a large amount of heat, thereby heating the water in the container, so that the water generates steam and is drawn out, thereby driving the generator set to generate electricity. During the continuous combustion of coal, smoke is generated, and the smoke contains dust (fly ash, carbon black, etc.), sulfur and nitrogen oxides, and other substances.
[0037] The heat exchanger 200 is a device that can realize heat transfer between two or more fluids of different temperatures, so that heat is transferred from a fluid with a higher temperature to a fluid with a lower temperature. The heat exchanger 200 is connected to the boiler 100, and the flue gas generated in the boiler 100 is transported to the heat exchanger 200 for heat exchange. The heat exchanger 200 can have various structural forms, such as a partition heat exchanger, a heat storage heat exchanger, a direct contact heat exchanger, etc. It can be understood that the connection between the heat exchanger 200 and the boiler 100 means that the heat exchanger 200 and the boiler 100 can cooperate with each other to realize the introduction of flue gas into the heat exchanger 200. The heat exchanger 200 can be directly connected to the boiler 100 or indirectly connected to the boiler 100. The connection between the various components below is also the same, and it will not be repeated.
[0038] The fan 400 is a fluid machine that relies on input mechanical energy to increase gas pressure and discharge gas. The fan 400 inputs external air into the heat exchanger 200 to exchange heat with the flue gas. The air input by the fan 400 is called primary air. Since the flue gas carries a large amount of heat when it is discharged from the boiler 100, the heat will be transferred from the flue gas to the primary air in the heat exchanger 200. The primary air absorbs the heat of the flue gas and is output to the coal mill 500.
[0039] The coal mill 500 is a machine that breaks up the coal and grinds it into coal powder. For example, the coal blocks are crushed into coal powder by crushing, smashing and grinding, so that the coal powder is easier to burn in the furnace. The primary air that absorbs the heat of the flue gas is transported to the coal mill 500 and mixed with the coal powder and then sent to the furnace of the boiler 100 for combustion. The coal mill 500 can input the primary air and coal powder mixture into the furnace from both sides of the boiler 100 through two pipes to improve the combustion efficiency.
[0040] As can be seen from the above, by setting the heat exchanger 200, the high-temperature flue gas generated by the boiler 100 is guided to the heat exchanger 200 to exchange heat with the primary air, so as to achieve the purpose of using the heat of the high-temperature flue gas to heat the primary air, increase the wind temperature of the primary air, reduce the furnace ignition height and ignition time of the boiler 100, improve the peak-shaving capacity of the boiler 100, and provide favorable conditions for the low-load stable combustion of the boiler 200. Compared with the prior art method of setting a heater to heat the primary air, the present application uses the heat of the high-temperature flue gas to heat the primary air, which fully utilizes the heat of the flue gas, reduces power consumption, reduces carbon emissions, and is more environmentally friendly.
[0041] Continue to combine Figure 1 As shown, in some embodiments, the primary air reheating system for a pulverized coal boiler further includes a cyclone separator 300, and the heat exchanger 200 is connected to the boiler 100 via the cyclone separator 300. The flue gas is input into the heat exchanger 200 after being processed by the cyclone separator 300, thereby reducing the dust content of the flue gas, avoiding clogging of the heat exchanger 200, and ensuring the heat exchange efficiency of the heat exchanger 200.
[0042] Specifically, the cyclone separator 300 is a dry gas-solid separation device that uses the centrifugal force generated by the high-speed rotation of the gas-solid mixture to separate dust from the airflow. The working principle is to rely on the rotational motion caused by the tangential introduction of the airflow to throw large dust particles with large inertial centrifugal force to the outer wall and separate. Since the centrifugal force on the dust particles is much greater than the gravity and inertia, the separation efficiency is relatively high.
[0043] The cyclone separator 300 is connected to the boiler 100, and the heat exchanger 200 is connected to the cyclone separator 300. For example, the cyclone separator 300 has a first inlet 310 and a first discharge port 320, and the heat exchanger 200 has a first inlet 210 and a first outlet 220, and a second inlet 230 and a second outlet 240. The first inlet 310 is connected to the boiler 100 through a pipeline, and the first discharge port 320 is connected to the first inlet 210 through a pipeline. The flue gas generated when the boiler 100 is working is input from the first inlet 310 to the cyclone separator 300 for processing. The cyclone separator 300 separates the large dust particles in the flue gas and then discharges the flue gas through the first discharge port 320. This part of the flue gas is input to the heat exchanger 200 through the first inlet 210 and output from the first outlet 220. The primary air enters from the second inlet 230 and outputs from the second outlet 240 under the drive of the fan 400, so that the flue gas and the primary air are heat exchanged. The second outlet 240 is connected to the coal mill 500. Since the dust content contained in the flue gas input to the heat exchanger 200 has been greatly reduced, the pipe wall of the heat exchanger 200 is not easily covered by dust, which can effectively ensure the heat exchange efficiency and avoid frequent cleaning of the heat exchanger 200.
[0044] Further, continue to combine Figure 1 As shown, in some embodiments, the boiler 100 is provided with a flue 110, and the cyclone separator 300 is connected to the flue 110 of the boiler 100 to avoid affecting the combustion of coal powder in the furnace.
[0045] Specifically, the flue gas generated during the operation of the boiler 100 is discharged through the flue 110. The flue 110 will not affect the combustion of the pulverized coal in the furnace, and various devices can be provided on the flue 110 to process the flue gas. The cyclone separator 300 is connected to the flue 110 of the boiler 100 to prevent the cyclone separator 300 from being connected to the furnace and causing the pulverized coal in the furnace to enter the cyclone separator 300 without being fully burned, thereby improving safety.
[0046] Further, continue to combine Figure 1 As shown, in some embodiments, the primary air reheating system for a pulverized coal boiler also includes a dust collector 600, which is connected to the cyclone separator 300 to process the dust discharged by the cyclone separator 300. In this way, the dust separated by the cyclone separator 300 can be processed to avoid polluting the environment.
[0047] Specifically, the cyclone separator 300 has a first inlet 310, a first discharge port 320 and a second discharge port 330. The first inlet 310 is connected to the boiler 100 through a pipeline, the first discharge port 320 is connected to the heat exchanger 200 through a pipeline, and the second discharge port 330 is connected to the dust collector 600 through a pipeline. The flue gas generated when the boiler 100 is working is input from the first inlet 310 to the cyclone separator 300 for treatment, and large particles of dust in the flue gas are separated. This part of the dust is input to the dust collector 600 through the second discharge port 330 for treatment.
[0048] Further, continue to combine Figure 1 As shown, in some embodiments, the first outlet 220 is connected to the dust collector 600, so that the fine dust particles in the flue gas after heat exchange can be further removed to prevent it from being discharged into the atmosphere and polluting the air.
[0049] Specifically, the heat exchanger 200 has a first inlet 210 and a first outlet 220. The flue gas treated by the cyclone separator 300 enters the heat exchanger 200 from the first inlet 210 and exchanges heat with the primary air. The flue gas after heat exchange is discharged from the first outlet 220 to the dust collector 600. The cyclone separator 300 and the heat exchanger 200 can be connected to the same dust collector 600 or to different dust collectors 600. Connecting to the same dust collector 600 can save the number of dust collectors 600, reduce costs, and facilitate the arrangement of equipment. For example, the first outlet 220 is connected to a pipeline, and the second discharge port 330 is connected to a pipeline. The two aforementioned pipelines are merged into one pipeline and connected to the dust collector 600.
[0050] The flue gas discharged from the boiler 100 is processed by the cyclone separator 300 to remove large particles of dust, but still contains small particles of dust. Therefore, the dust collector 600 is set to process the flue gas after heat exchange in the heat exchanger 200, so that the dust content in the flue gas can be further reduced and the pollution to the atmosphere can be minimized. In addition, since the cyclone separator 300 removes large particles of dust in the flue gas, even if there are small particles of dust, it is not easy to accumulate in the heat exchanger 200. The small particles of dust can flow out of the heat exchanger 200 and enter the dust collector 600 along with the flow of the flue gas. The dust collector 600 is set at the exhaust downstream of the heat exchanger 200, which will not waste too much heat of the flue gas processed by the cyclone separator 300, and can also filter small particles of dust to the maximum extent.
[0051] In other embodiments, the cyclone separator 300 may be omitted and the dust collector 600 may be directly provided. For example, the heat exchanger 200 has a first inlet 210 and a first outlet 220. The first inlet 210 is connected to the boiler 100 through a pipeline, and the first outlet 220 is connected to the dust collector 600 through a pipeline. The flue gas generated by the boiler 100 is directly transported to the heat exchanger 200 through a pipeline to exchange heat with the primary air. The flue gas after heat exchange is transported to the dust collector 600 through the first outlet 220. The dust collector 600 removes dust from the flue gas and then discharges it into the atmosphere. This method can also achieve heat exchange between the flue gas of the boiler 100 and the primary air. However, since the flue gas contains more dust, it may have an adverse effect on the heat exchanger 200, and the heat exchanger 200 needs to be cleaned more frequently.
[0052] Continue to combine Figure 1 As shown, in some embodiments, the heat exchanger 200 is a tubular heat exchanger 200, the flue gas flows outside the pipe of the tubular heat exchanger 200, and the primary air flows inside the pipe of the tubular heat exchanger 200. In this way, even if the dust contained in the flue gas adheres to the heat exchanger 200, it will only adhere to the outer wall of the pipe of the heat exchanger 200, making it convenient for the staff to clean the heat exchanger 200.
[0053] Continue to combine Figure 1 As shown, in some embodiments, the primary air reheating system for a pulverized coal boiler further includes a smoke exhaust duct 700, which is connected to the dust collector 600. The smoke exhaust duct 700 is cylindrical and is arranged vertically to the ground. The smoke is discharged into the smoke exhaust duct 700 after being dusted by the dust collector 600. Since the smoke exhaust duct 700 has a certain height, the diffusion of pollutants in the smoke can reduce the impact on the surrounding environment.
[0054] The working process of the primary air reheating system for a pulverized coal boiler is as follows: pulverized coal burns in the boiler 100, and the combustion of pulverized coal generates flue gas with a certain amount of heat. The flue gas is transported to the cyclone separator 300 for treatment. The cyclone separator 300 separates large particles of dust from the flue gas, and the treated flue gas is discharged into the heat exchanger 200. The fan 400 inputs primary air into the heat exchanger 200, so that the primary air exchanges heat with the flue gas in the heat exchanger 200. The dust separated by the cyclone separator 300 and the flue gas after heat exchange in the heat exchanger 200 are transported to the dust collector 600 for further dust removal. After dust removal, the dust collector 600 discharges the flue gas into the exhaust duct 700 and then discharged into the atmosphere. The primary air after heat exchange is transported to the pulverizer 500 and mixed with the pulverized coal and then continued to be transported to the boiler 100, thereby increasing the wind temperature of the primary air, reducing the ignition height and ignition time of the furnace, and improving the peak-shaving capacity of the boiler 100.
[0055] The above description is only a preferred embodiment of the present application, and does not limit the patent scope of the present application. All equivalent structural changes made based on the concept of the present application and the contents of the present application description and drawings, or direct / indirect application in other related technical fields are included in the patent protection scope of the present application.
Claims
1. A primary air reheating system for a pulverized coal boiler, characterized in that: include: boiler; a heat exchanger connected to the boiler to receive the flue gas generated by the boiler; A fan, the fan is connected to the heat exchanger to convey primary air to the heat exchanger, and the primary air and the flue gas exchange heat in the heat exchanger; as well as A coal mill is connected to the boiler and the heat exchanger respectively, and the primary air after heat exchange is transported to the coal mill and then mixed with coal powder and transported to the boiler.
2. The primary air reheating system for a pulverized coal boiler according to claim 1, characterized in that: The primary air reheating system for a pulverized coal boiler further comprises a cyclone separator, the heat exchanger is connected to the boiler via the cyclone separator, and the flue gas is input into the heat exchanger after being processed by the cyclone separator.
3. The primary air reheating system for a pulverized coal boiler according to claim 2, characterized in that: The boiler is provided with a flue, and the cyclone separator is connected to the flue of the boiler.
4. The primary air reheating system for a pulverized coal boiler according to claim 2, characterized in that: The primary air reheating system for a pulverized coal boiler further comprises a dust collector, which is connected to the cyclone separator to process dust discharged by the cyclone separator.
5. The primary air reheating system for a pulverized coal boiler according to claim 4, characterized in that: The cyclone separator is provided with a first inlet, a first discharge port and a second discharge port, the heat exchanger is provided with a first inlet and a first outlet, the first inlet is connected to the boiler, the first discharge port is connected to the first inlet, and the second discharge port is connected to the dust collector.
6. The primary air reheating system for a pulverized coal boiler according to claim 5, characterized in that: The first outlet is connected to the dust collector.
7. The primary air reheating system for a pulverized coal boiler according to claim 6, characterized in that: The first outlet and the second discharge port are connected to the same dust collector.
8. The primary air reheating system for a pulverized coal boiler according to claim 5, characterized in that: The heat exchanger is further provided with a second inlet and a second outlet. The primary air enters the heat exchanger from the second inlet for heat exchange and is discharged from the second outlet to be transported to the coal mill.
9. The primary air reheating system for a pulverized coal boiler according to claim 1, characterized in that: The primary air reheating system for a pulverized coal boiler further comprises a dust collector, and the dust collector is connected to the heat exchanger to process the flue gas after heat exchange.
10. The primary air reheating system for a pulverized coal boiler according to claim 4, characterized in that: The primary air reheating system for a pulverized coal boiler further comprises a smoke exhaust pipe, and the smoke exhaust pipe is connected to the dust collector.
11. The primary air reheating system for a pulverized coal boiler according to claim 1, characterized in that: The heat exchanger is a tubular heat exchanger, the flue gas flows outside the pipe of the tubular heat exchanger, and the primary air flows inside the pipe of the tubular heat exchanger.