Bottom circulating ash system of BFB boiler

Abstract

The utility model relates to the technical field of BFB boiler ash circulation, in particular to a BFB boiler bottom circulating ash system, which is characterized in that a mixture containing solid particles and high-temperature gas generated from a hearth outlet enters a separator to be separated. And the separated high-temperature gas is guided into a heating bin in the air inlet pipe through a waste gas pipe. Meanwhile, the fan feeds fluidization air into the air inlet pipe, and the fluidization air flows in a channel between the inner side wall of the air inlet pipe and the outer side wall of the heating bin. As the heating bin is filled with high-temperature gas, heat can be transferred from the heating bin to the fluidization air flowing through the channel, and the temperature of the fluidization air is increased. The heated fluidization air enters the material returning device, heat energy of separated high-temperature gas is fully recycled and used for heating the fluidization air, the overall utilization efficiency of energy is improved, the heated fluidization air is beneficial to maintaining uniform distribution of the temperature in a hearth, the problem of unstable operation caused by uneven temperature is solved, and stable operation of the boiler is guaranteed. The method can be widely applied to the field of BFB boiler ash circulation.

Description

TECHNICAL FIELD

[0001] The utility model relates to BFB boiler ash circulation technical field, concretely relates to a kind of BFB boiler bottom circulating ash system. BACKGROUND

[0002] In energy production, bubbling fluidized bed BFB boiler is a common device. When BFB boiler runs, mixture containing solid particles and high-temperature gas is generated at furnace outlet. After separation by separator, solid particles re-enter the boiler through return feeder, and high-temperature gas is discharged after treatment; Currently, the heat energy contained in the separated high-temperature gas is often not fully utilized but discharged, causing energy waste.

[0003] On the other hand, the fluidization air temperature entering BFB boiler is usually low. When low-temperature fluidization air enters the boiler with ash, it will cause uneven temperature distribution in the furnace, affecting the fluidization effect and combustion efficiency of the material. This may lead to insufficient fuel combustion, increase pollutant emissions, and even affect the stable operation and overall performance of the boiler. SUMMARY

[0004] In view of the problem that the heat energy contained in the high-temperature gas separated by the separator in the prior art is often not fully utilized but discharged, and the fluidization air temperature entering the BFB boiler is low, affecting the normal operation of the boiler; The utility model provides a BFB boiler bottom circulating ash system.

[0005] To solve the above technical problems, the utility model is solved by the following technical scheme:

[0006] A BFB boiler bottom circulating ash system, comprising a separator, a return feeder, a communication pipe and a waste gas pipe, further comprising a fan for providing fluidization air to the return feeder and an air inlet pipe, a heating bin is provided in the air inlet pipe, a passage for fluidization air is formed between the inner side wall of the air inlet pipe and the outer side wall of the heating bin; One end of the waste gas pipe penetrates the side wall of the air inlet pipe and communicates with the inner cavity of the heating bin, further comprising an exhaust pipe connected with the inner cavity of the heating bin, one end of the exhaust pipe extends from the side wall of the air inlet pipe.

[0007] In the operation process of the BFB boiler bottom ash recycling system, the mixture of solid particles and high-temperature gas generated from the furnace outlet enters the separator for separation. The high-temperature gas after separation is introduced into the heating bin in the air inlet pipe through the exhaust pipe. At the same time, the blower sends the fluidized air into the air inlet pipe, and the fluidized air flows in the channel between the inner wall of the air inlet pipe and the outer wall of the heating bin. Because the heating bin is filled with high-temperature gas, heat is transferred from the heating bin to the fluidized air flowing through the channel, so that the temperature of the fluidized air is increased. The heated fluidized air enters the return feeder to provide suitable conditions for the circulation and fluidization of the material. After completing the heat exchange, part of the gas in the heating bin is discharged through the exhaust pipe.

[0008] The heat energy of the separated high-temperature gas is fully recovered to heat the fluidized air, which improves the overall utilization efficiency of energy and reduces energy waste. The heated fluidized air helps to maintain uniform distribution of temperature in the furnace, reduces the problem of unstable operation caused by uneven temperature, and ensures stable operation of the boiler.

[0009] As a preferred, the heating bin is cylindrical, and mounting rods are uniformly fixed on the cylindrical side wall of the heating bin, and the other end of the mounting rod is fixed on the inner side wall of the air inlet pipe.

[0010] The cylindrical design of the heating bin makes the flow of high-temperature gas in the bin more uniform, and the heat distribution more balanced. The mounting rods uniformly fixed on the cylindrical side wall of the heating bin stably connect the heating bin to the inner side wall of the air inlet pipe, ensuring that the position of the heating bin is fixed during the operation of the system and does not shake or displace, thereby ensuring the stability and reliability of the heat exchange process.

[0011] As a preferred, the mounting rods are arranged at positions close to both ends of the cylindrical side wall of the heating bin.

[0012] By arranging the mounting rods at positions close to both ends of the cylindrical side wall of the heating bin, the internal space and the external channel space of the heating bin can be occupied to the maximum extent while ensuring stable support for the heating bin. The layout of both ends makes the installation of the heating bin in the air inlet pipe more balanced and stable, reducing the deformation or displacement that may be caused by uneven stress.

[0013] As a preferred, the mounting rod is provided with a cavity, and the cavity is in communication with the inner cavity of the heating bin.

[0014] When the high-temperature gas enters the heating bin, part of the gas can enter the cavity inside the mounting rod. Since the cavity is in communication with the inner cavity of the heating bin, the mounting rod can also be heated by the high-temperature gas. When the fluidized air passes through the channel between the air inlet pipe and the heating bin, the heated mounting rod can further transfer heat to the fluidized air, thereby improving the overall heating effect.

[0015] As preferred, the inner side wall of the heating bin is uniformly provided with a plurality of baffles, and the baffle and the inner side wall of the heating bin form an airflow channel for the airflow to pass through.

[0016] When the high-temperature gas enters the heating bin, the flow direction of the high-temperature gas is changed under the action of the baffles. The airflow channel formed between the baffle and the inner side wall of the heating bin makes the flow path of the high-temperature gas become tortuous and complex. This increases the residence time of the high-temperature gas in the heating bin, increases the contact time and contact area with the inner side wall of the heating bin and the mounting rod and other components; prolonging the residence time and increasing the contact area of the high-temperature gas, significantly strengthening the heat exchange between the high-temperature gas and the heating bin and the mounting rod, thereby more effectively improving the heating effect of the fluidized wind.

[0017] As preferred, the air inlet pipe is provided with a filter screen at the connection with the return feeder.

[0018] When the BFB boiler is shut down, the fan will also be closed. Due to factors such as airflow disturbance, part of the ash in the return feeder may have a tendency to move to the air inlet pipe. At this time, the filter screen provided at the connection between the air inlet pipe and the return feeder can block these ashes from entering the air inlet pipe and the fan. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 It is a schematic diagram of the overall structure of the BFB boiler bottom circulating ash system in the embodiment;

[0020] Figure 2 It is a schematic diagram of the structure of the air inlet pipe in the embodiment;

[0021] Figure 3 It is a schematic diagram of the structure of the air inlet pipe and the heating bin at the cross section in the embodiment;

[0022] Figure 4 It is a schematic diagram of the structure of the heating bin in the embodiment;

[0023] Figure 5 It is a schematic diagram of the structure of the heating bin at the cross section in the embodiment.

[0024] The names of the parts referred to by the respective numbers in the drawings are as follows:

[0025] 110, separator; 1101, feed pipe; 120, return feeder; 1201, discharge pipe; 130, communication pipe; 140, exhaust pipe; 150, fan; 160, air inlet pipe; 1601, filter screen; 170, heating bin; 1701, baffle; 180, exhaust pipe; 190, mounting rod; 1901, cavity. DETAILED DESCRIPTION

[0026] For further understanding of the content of the utility model, the utility model is described in detail in combination with the drawings and examples. It should be understood that the examples are merely to explain the utility model and not to limit it.

[0027] Embodiment

[0028] As Figures 1-5 shown, a BFB boiler bottom circulating ash system mainly consists of a separator 110, a return feeder 120, a connecting pipe 130, a waste gas pipe 140, a fan 150, an air inlet pipe 160, a heating bin 170 and an exhaust pipe 180.

[0029] The ash discharged from the boiler enters the separator 110 through the feeding pipe 1101. The separator 110 is used to separate the mixture of solid particles and high-temperature gas generated at the outlet of the furnace. The separated solid particles enter the return feeder 120 through the connecting pipe 130 and then enter the boiler through the discharge pipe 1201. The high-temperature gas enters the waste gas pipe 140. One end of the waste gas pipe 140 is connected with the separator 110, and the other end penetrates through the side wall of the air inlet pipe 160 and is connected with the inner cavity of the heating bin 170 in the air inlet pipe 160. The fan 150 is used to provide fluidizing air to the return feeder 120, and the fluidizing air is delivered through the air inlet pipe 160. The air inlet pipe 160 is provided with a cylindrical heating bin 170, and the inner side wall of the air inlet pipe 160 and the outer side wall of the heating bin 170 form a channel for the fluidizing air to pass through. The cylindrical side wall of the heating bin 170 is uniformly fixed with mounting rods 190 near both ends, and the other end of the mounting rod 190 is fixed on the inner side wall of the air inlet pipe 160. The mounting rod 190 is provided with a cavity 1901 connected with the inner cavity of the heating bin 170. The inner side wall of the heating bin 170 is uniformly distributed with multiple baffles 1701, and each baffle 1701 and the inner side wall of the heating bin 170 form an airflow channel for the airflow to pass through. One end of the exhaust pipe 180 is connected with the inner cavity of the heating bin 170, and the other end extends out of the side wall of the air inlet pipe 160. A filter screen 1601 is arranged at the connection between the air inlet pipe 160 and the return feeder 120.

[0030] The use principle of the BFB boiler bottom circulating ash system in the embodiment is as follows:

[0031] When the BFB boiler is running, the mixture of solid particles and high-temperature gas generated at the furnace outlet enters the separator 110 for separation. The separated high-temperature gas is introduced into the heating bin 170 in the air inlet pipe 160 through the exhaust pipe 140, and the solid particles enter the return feeder 120. At the same time, the blower 150 is started to send the fluidizing air into the air inlet pipe 160, and the fluidizing air flows in the passage between the inner wall of the air inlet pipe 160 and the outer wall of the heating bin 170. Since the heating bin 170 is filled with high-temperature gas, heat is transferred from the heating bin 170 to the fluidizing air, so that the temperature of the fluidizing air is increased. After completing the heat exchange, part of the high-temperature gas in the heating bin 170 is discharged through the exhaust pipe 180. The heated fluidizing air enters the return feeder 120 to provide suitable conditions for the circulation and fluidization of the material.

[0032] In the embodiment, the BFB boiler bottom ash recycling system recovers the heat energy of the separated high-temperature gas to heat the fluidizing air, thereby improving the overall energy utilization efficiency and reducing energy waste.

[0033] The heated fluidizing air runs stably: it helps to maintain uniform distribution of the temperature in the furnace, reduces the problem of unstable operation caused by uneven temperature, and ensures stable operation of the boiler. The filter screen 1601 can prevent the ash in the return feeder 120 from entering the air inlet pipe 160 and the blower 150 after the boiler is stopped, thereby preventing damage to the equipment.

[0034] The special design of the heating bin 170 and the arrangement of the baffle 1701 increase the heat exchange effect, so that the fluidizing air is heated more fully.

[0035] In summary, the above is only a preferred embodiment of the present embodiment, and any changes and modifications made within the scope of the patent application of the present embodiment should be included in the scope of the present embodiment.

Claims

1. A BFB boiler bottom ash recycling system comprising a separator (110), a return feeder (120), a connecting pipe (130) and a waste gas pipe (140), characterized in that: The device further comprises a fan (150) and an air inlet pipe (160) for providing fluidizing air to the return device (120), the air inlet pipe (160) is provided with a heating chamber (170), and a channel for the fluidizing air is formed between the inner wall of the air inlet pipe (160) and the outer wall of the heating chamber (170); one end of the exhaust pipe (140) is connected to the inner cavity of the heating chamber (170) through the side wall of the air inlet pipe (160), and the device further comprises an exhaust pipe (180) connected to the inner cavity of the heating chamber (170), and one end of the exhaust pipe (180) extends from the side wall of the air inlet pipe (160).

2. A BFB boiler bottom ash system according to claim 1, characterized in that: The heating chamber (170) is cylindrical, and mounting rods (190) are uniformly fixed on the cylindrical side wall of the heating chamber (170), and the other ends of the mounting rods (190) are fixed on the inner wall of the air inlet pipe (160).

3. A BFB boiler bottom ash system according to claim 2, characterized in that: The mounting rods (190) are arranged near the two ends of the cylindrical side wall of the heating chamber (170).

4. A BFB boiler bottom ash system according to claim 2, characterized in that: The mounting rods (190) are provided with cavities (1901) inside, and the cavities (1901) are connected to the inner cavity of the heating chamber (170).

5. A BFB boiler bottom ash system according to claim 1, characterized in that: The inner wall of the heating chamber (170) is uniformly provided with a plurality of baffles (1701), and a gas flow channel for the gas flow is formed between each baffle (1701) and the inner wall of the heating chamber (170).

6. A BFB boiler bottom ash system according to claim 1, characterized in that: The air inlet pipe (160) is provided with a filter screen (1601) at the connection with the return device (120).

Images