Stable combustion device for improving low-load stable combustion performance

Abstract

The utility model discloses a stable combustion device capable of improving low-load stable combustion performance, which is characterized in that a hot primary air duct is communicated and connected between an outlet of an air pre-heater and an inlet of a coal mill, a high-temperature air pipe is communicated and connected between the hot primary air duct and a combustor, and a primary air powder pipeline is communicated and connected between an outlet of the coal mill and the combustor; the heating tank is installed on the high-temperature air pipe, the vacuum heat pipe heater is composed of a plurality of heat pipes, each heat pipe is provided with a heat absorption end and a putting-in end, the heat absorption ends of the heat pipes are located in a hearth of the boiler, the heat release ends of the heat pipes are located in the heating tank, and the two ends of the circulating pipe are communicated with the high-temperature air pipe. One path of hot air is led out from hot primary air between the outlet of the original air pre-heater and the inlet of the coal mill, is heated by the vacuum heat pipe heater and then is connected into the inlet of the combustor, so that the temperature of primary air powder is increased, volatile matters in coal powder are separated out in advance, and the ignition capacity and the stable combustion capacity of the combustor are improved.

Description

Technical Field

[0001] This utility model relates to the field of combustion equipment technology for thermal power units, and more specifically, to a combustion stabilization device for improving low-load combustion stability performance. Background Technology

[0002] With the increasing proportion of new energy sources such as wind power and solar energy, thermal power units are operating under increasingly lower loads, and the unit loads are also decreasing. Coal-fired power units typically use pulverized coal burners. Pulverized coal, ground in a ball mill, is introduced into the burner located in the furnace through a primary air duct. To achieve good grinding and combustion, the primary air entering the mill is first heated to a certain temperature by an air preheater. This hot primary air dries the raw coal inside the mill. After the raw coal is ground into pulverized coal, the primary air carries the pulverized coal through the primary air-coal duct into the burner. The pulverized coal begins to burn at a certain temperature, releasing heat. Pulverized coal requires a certain temperature to burn inside the burner; it must reach its ignition point before combustion can occur. If the primary air-coal temperature or the furnace temperature is too low, combustion stability is poor, and the flameout is likely. If the primary air-coal temperature is too high, spontaneous combustion can easily occur within the primary air duct.

[0003] As the requirements for deep peak shaving of power units become increasingly stringent and low-load combustion conditions become more frequent, the combustion stability of burners under low-load conditions is required to be increasingly higher. However, during the low-load operation of boilers, the furnace temperature is low, the burner power decreases, and burner flameout is very likely to occur. Summary of the Invention

[0004] The purpose of this invention is to provide a combustion stabilization device that improves the combustion stabilization performance under low load.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows: a combustion stabilization device for improving low-load combustion stability performance, comprising a boiler, an air preheater, a coal mill and a burner, and further comprising a circulation pipe, a heating tank and a vacuum heat pipe heater;

[0006] The boiler's tail flue is connected to the air preheater inlet. A hot primary air duct is connected between the air preheater outlet and the coal mill inlet. A high-temperature air duct is connected between the hot primary air duct and the burner. A primary air-coal pipeline is connected between the coal mill outlet and the burner. The heating tank is installed on the high-temperature air duct. The vacuum heat pipe heater consists of multiple heat pipes, each with an absorption end and an outlet end. The absorption end of the heat pipe is located in the boiler furnace, and the discharge end is located inside the heating tank. The two ends of the circulation pipe are connected to the high-temperature air duct, and are respectively close to the inlet and outlet ends of the heating tank.

[0007] Preferably, a first solenoid valve is installed at the connection between the high-temperature air duct and the hot primary air duct.

[0008] Preferably, a second solenoid valve is installed on the circulation pipe, and a temperature sensor and a third solenoid valve are installed on the high-temperature air duct, with the temperature sensor located near the air outlet of the heating tank.

[0009] Preferably, heat dissipation fins are installed on the outer surface of the heat-dissipating end of the vacuum heat pipe heater.

[0010] Preferably, a fan is installed at the air inlet end of the heating tank.

[0011] Compared with the prior art, the advantages of this utility model are:

[0012] This invention draws a hot air stream from the hot primary air between the original air preheater outlet and the coal mill inlet. After being heated by a vacuum heat pipe heater, the hot air is introduced into the burner inlet. The high-temperature hot air mixes with the original primary air and pulverized coal in the system at the burner inlet, further increasing the temperature of the primary air and pulverized coal, allowing the volatiles in the pulverized coal to be released in advance, and improving the burner's ignition ability and stable combustion ability.

[0013] Meanwhile, the temperature sensor can detect the temperature of the hot air in the high-temperature duct. After the hot air is discharged from the fan into the heating tank, it can be repeatedly re-entered into the heating tank through the circulation pipe, thereby repeatedly heating the hot air so that the hot air at the appropriate temperature can enter the burner and improve the combustion efficiency. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a structural diagram of a combustion stabilization device for improving low-load combustion stability according to this utility model.

[0016] In the diagram: 1. Boiler; 2. Air preheater; 3. Coal mill; 4. Heating tank; 5. Burner; 6. Hot primary air duct; 7. Primary air-coal pipeline; 8. High-temperature air duct; 9. First solenoid valve; 10. Fan; 11. Tail flue; 12. Vacuum heat pipe heater; 13. Circulation pipe; 14. Second solenoid valve; 15. Temperature sensor; 16. Third solenoid valve. Detailed Implementation

[0017] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the scope of protection of the present invention.

[0018] See Figure 1 As shown, this utility model provides a combustion stabilization device to improve the low-load combustion stabilization performance, including a boiler, an air preheater 2, a coal mill 3 and a burner 5, and also includes a circulation pipe 13, a heating tank 4 and a vacuum heat pipe heater 12.

[0019] The tail flue 11 of the boiler 1 is connected to the inlet of the air preheater 2. A hot primary air duct 6 connects the outlet of the air preheater 2 to the inlet of the coal mill 3. A high-temperature air duct 8 connects the hot primary air duct 6 to the burner 5. A primary air-coal pipeline 7 connects the outlet of the coal mill 3 to the burner 5. The heating tank 4 is installed on the high-temperature air duct 8. The vacuum heat pipe heater 12 is composed of multiple heat pipes, each having an absorption end and an insertion end. The hot end is located in the furnace of boiler 1, the heat-releasing end of the heat pipe is located in the heating tank 4, and the heat-absorbing end is used to absorb heat in the furnace and heat the working fluid inside the heat pipe. When the working fluid evaporates, it absorbs heat and fills the heat-releasing end. The heat-releasing end is connected to the primary air. During the heat release process, the primary air is heated and the working fluid inside the heat pipe is cooled to a condensate state and flows back to the heat-absorbing end. This process is repeated. The two ends of the circulation pipe 13 are connected to the high-temperature air duct 8. The two ends of the circulation pipe 13 are close to the air inlet and air outlet of the heating tank 4, respectively.

[0020] In this embodiment, a first solenoid valve 9 is installed at the connection between the high-temperature air duct 8 and the hot primary air duct 6.

[0021] To ensure that the high-temperature air duct 8 can discharge hot air at a suitable temperature, in this embodiment, a second solenoid valve 14 is installed on the circulation pipe 13, and a temperature sensor 15 and a third solenoid valve 16 are installed on the high-temperature air duct 8. The temperature sensor 15 is located near the air outlet of the heating tank 4.

[0022] In this embodiment, heat dissipation fins are installed on the outer surface of the heat-dissipating end of the vacuum heat pipe heater 12 to further expand the heat-receiving surface and improve the heat exchange efficiency.

[0023] Furthermore, since the hot air drawn from the hot primary air between the outlet of the original air preheater 2 and the inlet of the coal mill 3 does not pass through the coal mill 3 and the coal powder separator, the resistance is less than the resistance of the primary air-coal powder pipeline, and the air pressure is higher than the air pressure of the primary air pipeline at the burner 5 position. In order to enhance the flow, in this embodiment, a fan 10 is installed at the air inlet end of the heating tank 4.

[0024] By drawing a hot air stream from the hot primary air between the outlet of the original air preheater 2 and the inlet of the coal mill 3, passing through the vacuum heat pipe heater 12, the heated high-temperature hot air is connected to the inlet of the burner 5 through the high-temperature air duct 8. The high-temperature hot air mixes with the original primary air and pulverized coal in the system at the inlet of the burner 5, further increasing the temperature of the primary air and pulverized coal, releasing the volatiles in the pulverized coal in advance, and improving the ignition capability and stable combustion capability of the burner.

[0025] Temperature sensor 15 can detect the temperature of hot air in high-temperature duct 8. If the temperature does not reach the appropriate temperature, the third solenoid valve 16 is closed and the second solenoid valve 14 is opened by remote control switch. At this time, the hot air sent by fan 10 to heating tank 4 can be discharged and re-enter heating tank 4 through circulation pipe 13, so as to reheat the hot air. When the hot air temperature reaches the appropriate temperature, the second solenoid valve 16 is opened again, and the hot air that meets the temperature requirements can enter the burner.

[0026] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, the patent owner may make various modifications or alterations within the scope of the appended claims, as long as they do not exceed the protection scope described in the claims of the present invention, they shall all be within the protection scope of the present invention.

Claims

1. A combustion stabilization device for improving low-load combustion stability, comprising a boiler, an air preheater, a coal mill, and a burner, characterized in that: It also includes circulation pipes, heating tanks, and vacuum heat pipe heaters; The boiler's tail flue is connected to the air preheater inlet. A hot primary air duct is connected between the air preheater outlet and the coal mill inlet. A high-temperature air duct is connected between the hot primary air duct and the burner. A primary air-coal pipeline is connected between the coal mill outlet and the burner. The heating tank is installed on the high-temperature air duct. The vacuum heat pipe heater consists of multiple heat pipes, each with an absorption end and an outlet end. The absorption end of the heat pipe is located in the boiler furnace, and the discharge end is located inside the heating tank. The two ends of the circulation pipe are connected to the high-temperature air duct, and are respectively close to the inlet and outlet ends of the heating tank.

2. The combustion stabilization device for improving low-load combustion stability according to claim 1, characterized in that: A first solenoid valve is installed at the connection between the high-temperature air duct and the primary hot air duct.

3. The combustion stabilization device for improving low-load combustion stability according to claim 1, characterized in that: A second solenoid valve is installed on the circulation pipe, and a temperature sensor and a third solenoid valve are installed on the high-temperature air duct. The temperature sensor is located near the air outlet of the heating tank.

4. The combustion stabilization device for improving low-load combustion stability according to claim 1, characterized in that: The outer surface of the heat-dissipating end of the vacuum heat pipe heater is equipped with heat dissipation fins.

5. A combustion stabilization device for improving low-load combustion stability according to claim 1, characterized in that: A fan is installed at the air inlet of the heating tank.

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