CN114234178B

CN114234178B - Fly ash recirculation system of fluidized bed boiler

Info

Publication number: CN114234178B
Application number: CN202111286187.2A
Authority: CN
Inventors: 谢浩琦; 奚晓兵; 陶卫中; 邵淼清; 方凌健
Original assignee: Pinghu Hongxin Thermal Power Co ltd
Current assignee: Pinghu Hongxin Thermal Power Co ltd
Priority date: 2021-11-02
Filing date: 2021-11-02
Publication date: 2022-07-12
Anticipated expiration: 2041-11-02
Also published as: CN114234178A

Abstract

The application discloses fluidized bed boiler flying dust recirculation system, including flying ash storehouse, boiler, still including the support body of erectting in the boiler top, support body fixedly connected with is the hollow jar that holds, flying ash storehouse sets up in the upper end that holds a jar inner chamber, the below that holds jar inner chamber and be located flying ash storehouse is provided with and is hollow processing storehouse, the fixed and intercommunication in flying ash storehouse lower extreme has grey storehouse pipe, grey storehouse pipe is fixed and wears to locate to handle the storehouse upper end, it is provided with the mechanism of holding temperature that is used for making the flying ash maintain the temperature to handle the storehouse inner chamber, it has lower grey pipe to handle the fixed and intercommunication in storehouse lower extreme, the ash pipe is fixed wears to locate to hold jar lower extreme and fixed and communicate in the boiler down. The fly ash circulating combustion device has the advantages that fly ash can be better circulated and combusted, and the effects of environmental protection and energy saving are achieved.

Description

Fly ash recirculation system of fluidized bed boiler

Technical Field

The application relates to the field of fluidized bed boilers, in particular to a fly ash recirculation system of a fluidized bed boiler.

Background

The circulating fluidized bed boiler has the advantages of wide fuel adaptability, clean combustion and the like, is rapidly developed in China, and has a large market share of the energy market in China.

The coal is combusted in the circulating fluidized bed boiler, the generated high-temperature flue gas carries a large amount of particles to leave the boiler and then enters the cyclone separator for gas-solid separation, and due to the fact that pulverized coal in the hearth is not sufficiently combusted, the separated particles can carry a large amount of fly ash, most of fly ash can be captured by the dust remover and sent to the fly ash bin, then the fly ash in the fly ash bin is sent back to the hearth through a pipeline for combustion supporting, the fly ash is recycled and combusted, and the effects of environmental protection and energy saving are achieved.

However, the temperature of the circulating fly ash in the fly ash bin can be further reduced after a certain storage time, which is not beneficial to burning out of carbon particles after the circulating fly ash returns to the hearth and influences the circulating combustion of the fly ash.

Disclosure of Invention

In order to enable better cyclic combustion of the fly ash, the application provides a fly ash recirculation system of a fluidized bed boiler.

The application provides a fluidized bed boiler fly ash recirculation system adopts following technical scheme:

the utility model provides a fluidized bed boiler flying dust recirculation system, includes flying ash storehouse, boiler, still includes the support body of erectting in the boiler top, support body fixedly connected with is hollow and holds the jar, flying ash storehouse sets up in the upper end that holds a jar inner chamber, the below that holds a jar inner chamber and be located flying ash storehouse is provided with and is hollow processing storehouse, the fixed and intercommunication in flying ash storehouse lower extreme has ash bin pipe, ash bin pipe is fixed and wears to locate to handle the storehouse upper end, it is provided with the mechanism that holds that is used for making the flying ash maintain the temperature to handle the storehouse inner chamber, it is fixed and the intercommunication has lower ash pipe to handle the storehouse lower extreme, ash pipe is fixed wears to locate to hold jar lower extreme and fixed and communicate in the boiler down.

By adopting the technical scheme, the flying ash in the flying ash bin falls into the treatment bin from the ash bin pipe, the temperature maintaining mechanism in the treatment bin enables the flying ash to maintain the temperature, the temperature drop caused by storage of the flying ash is weakened, meanwhile, the flying ash sent to the flying ash bin is captured by the dust remover and is higher when the flying ash just enters the flying ash bin, so that the flying ash bin and the treatment bin are both arranged in the containing tank, the heat energy of the flying ash bin can be transferred to the treatment bin, the treatment bin is wholly positioned in the environment with higher temperature, the temperature of the flying ash is better maintained, the flying ash can be fully combusted when returning to the hearth, and the environment protection and energy saving are realized.

Optionally, the temperature holding mechanism comprises a distribution plate fixedly connected to the inner wall of the treatment bin, the distribution plate is located at the upper end of the treatment bin, the distribution plate is arranged in a hollow mode, the lower end of the inner wall of the treatment bin is fixedly connected with a hollow convergence plate, a closed chamber is formed between the distribution plate, the convergence plate and the inner wall of the treatment bin, a plurality of communicating pipes are fixedly and communicated between the distribution plate and the convergence plate, the ash bin pipe penetrates through an inner cavity of the distribution plate, the ash bin pipe is fixed and communicated with the lower end of the convergence plate, the communicating pipes are provided with valves, and the frame body is provided with a heat supply assembly used for conveying a heat source to the closed chamber.

By adopting the technical scheme, the heat supply assembly conveys the heat source to the closed chamber, the fly ash in the fly ash bin enters the distribution plate from the ash bin pipe and falls into each communicating pipe, and is in a valve state at the moment, so that the fly ash can be stored in each communicating pipe, the heat source can maintain the temperature of the communicating pipes, the temperature drop of the fly ash is slowed down, when the fly ash needs to be added into the boiler, the valves are opened, and the fly ash in the communicating pipes falls into the convergence plate and falls into the boiler through the ash discharge pipe.

Optionally, the heat supply subassembly is including setting up in the heat supply water tank of support body, the heat supply water tank is the cavity setting, heat supply water tank inner wall fixedly connected with heater, heat supply water tank fixedly connected with delivery pipe, delivery pipe fixed connection is in the position that the processing storehouse is located the closed chamber, the position fixedly connected with circulating pipe that the processing storehouse is located the closed chamber, the circulating pipe is located the one side setting that the processing storehouse deviates from the delivery pipe, circulating pipe fixed connection is in the heat supply water tank.

Through adopting above-mentioned technical scheme, after flying the ash to fall into each communicating pipe, the hot water supply tank flows into the closed chamber with water from the delivery pipe, makes the hydroenergy through the heating enough surround communicating pipe around, heats communicating pipe to communicating pipe transmits the flying ash of temperature to its inner chamber, makes the flying ash can keep higher temperature.

Optionally, a plurality of springs are fixedly connected to the upper surface of the convergence plate and located between two adjacent communicating pipes, one ends of the springs are fixedly connected to the convergence plate, rubber balls are fixedly connected to the other ends of the springs, and the rubber balls are flush with the pipe orifices of the water supply pipe.

Through adopting above-mentioned technical scheme, through setting up spring and rubber ball, when water from the delivery pipe blowout, water can spout and hit on the rubber ball to the rubber ball receives the impulsive force, under the effect of spring, can collide at random, can strike at each communicating pipe wall, makes the flying dust in the communicating pipe receive the vibration, prevents that the flying dust from gathering the inner wall in communicating pipe, and then makes the flying dust fall down smoothly, and the random swing of rubber ball simultaneously can accelerate the mixture of the indoor water of closed chamber.

Optionally, the lower surface of the distributing plate is arranged in an arc shape, the arc-shaped protrusions of the lower surface of the distributing plate are arranged towards the communicating pipe, the lower surface of the converging plate is arranged in an arc shape, and the arc-shaped protrusions of the lower surface of the converging plate are arranged towards the ash discharge pipe.

Through adopting above-mentioned technical scheme, make the flying dust that falls into in the distributing plate can be more smooth fall into each communicating pipe, simultaneously the flying dust falls into from communicating pipe and assembles the board after, also can fall into down in the ash pipe smoothly, reduces the flying dust and gathers the lower surface at distributing plate and aggregation board.

Optionally, the inner wall of the treatment bin is provided with a temperature adjusting mechanism, and the temperature adjusting mechanism comprises:

the temperature sensor is arranged on the inner wall of the treatment bin and positioned at the position of the closed chamber, and is used for detecting the temperature of hot water in the closed chamber of the treatment bin and outputting a temperature detection signal;

the comparison circuit is preset with a temperature reference value, is connected with the output end of the temperature sensor, receives the temperature detection signal and outputs a comparison signal; and (c) a second step of,

and the control circuit is connected with the output end of the comparison circuit, is connected with the heater, receives the comparison signal and outputs a control signal for controlling the opening and closing of the heater based on the comparison signal.

By adopting the technical scheme, the temperature sensor detects the temperature of the water in the closed chamber in real time and sends the detected temperature in the form of a temperature detection signal, the comparison circuit receives the temperature detection signal and then converts the temperature detection signal into a corresponding temperature detection value, the temperature detection value is compared with a temperature reference value, and when the temperature detection value is lower than the temperature reference value, the control circuit controls the heater to be started, so that the heater heats the water.

Optionally, the comparison circuit includes a comparator a and a reference circuit, where the reference circuit includes a first resistor R1 and a second resistor R2, and is used for setting a temperature reference value;

the positive phase input end of the comparator A is connected with the first resistor R1, and the negative phase input end of the comparator A is connected with the output end of the temperature sensor;

one end of the first resistor R1 is connected to a power supply VCC, and the other end of the first resistor R1 is connected with the positive phase input end of the comparator A;

the second resistor R2 has one end connected to ground and the other end connected to the connection point of the first resistor R1 and the non-inverting input of the comparator a.

By adopting the technical scheme, the comparator A converts the temperature detection signal into a corresponding temperature detection value and compares the temperature detection value with the temperature reference value, and when the temperature detection value is smaller than the temperature reference value, the comparator A outputs a high level.

Optionally, the control circuit includes a triode Q, a relay KM, and a freewheeling diode D; wherein the content of the first and second substances,

a triode Q, the base of which is connected with the output end of the comparator A, and the emitter of which is grounded;

the relay KM comprises a coil and a normally open contact KM-1, one end of the coil is connected with a collector of the triode Q, the other end of the coil is connected with a power supply VCC, and the normally open contact KM-1 is connected in a power supply loop of the heater;

and the anode of the freewheeling diode D is connected between the coil and the collector of the triode Q, and the cathode of the freewheeling diode D is connected between the coil and the power supply VCC.

By adopting the technical scheme, when the comparator A outputs a high level, the triode Q is conducted, the coil of the relay KM is electrified, and the normally open contact KM-1 is closed.

Optionally, the communication pipe is spirally disposed.

Through adopting above-mentioned technical scheme, increase communicating pipe and hydrothermal area of contact, make the heat conductivility of communicating pipe better, better temperature of maintaining the flying ash.

In summary, the present application includes at least one of the following beneficial technical effects:

the fly ash in the fly ash bin falls into the treatment bin from the ash bin pipe, the temperature maintaining mechanism in the treatment bin enables the fly ash to maintain the temperature, the temperature drop of the fly ash caused by storage is weakened, meanwhile, the fly ash which is sent to the fly ash bin is captured by the dust remover and has higher temperature when the fly ash just enters the fly ash bin, so that the fly ash bin and the treatment bin are both arranged in the accommodating tank, the heat energy of the fly ash bin can be transmitted to the treatment bin, the whole treatment bin is in a higher-temperature environment, the temperature of the fly ash is better maintained, and the fly ash can be fully combusted when returning to the hearth.

The temperature sensor is used for detecting the temperature of water in the closed chamber and sending out the detected temperature in the form of a temperature detection signal, the comparison circuit receives the temperature detection signal, converts the temperature detection signal into a corresponding temperature detection value, compares the temperature detection value with a temperature reference value and then outputs a comparison signal, and the control circuit receives the comparison signal and controls the heater to be turned on and off.

Drawings

Fig. 1 is a schematic overall structure diagram of an embodiment of the present application.

Fig. 2 is a schematic view of the internal structure of the holding tank in the embodiment of the present application.

Fig. 3 is a schematic diagram of an internal structure of a treatment cabin embodied in the embodiment of the present application.

Fig. 4 is a circuit diagram of a temperature adjustment mechanism in an embodiment of the present application.

Description of the reference numerals:

1. a boiler; 2. a frame body; 3. a holding tank; 31. a support; 4. fly ash bin; 5. a processing bin; 41. a dust bin pipe; 6. a temperature holding mechanism; 51. a dust discharging pipe; 61. a distribution plate; 62. a communicating pipe; 63. a convergence plate; 64. a closed chamber; 65. a heat supply assembly; 651. a hot water supply tank; 652. a heater; 653. a water supply pipe; 654. a circulation pipe; 66. a spring; 67. a rubber ball; 7. a temperature adjustment mechanism; 71. a temperature sensor; 72. a comparison circuit; 73. a control circuit.

Detailed Description

The present application is described in further detail below with reference to figures 1-4.

The embodiment of the application discloses a fly ash recycling system of a fluidized bed boiler. Referring to fig. 1 and 2, a fluidized bed boiler flying dust recirculation system includes boiler 1, support body 2, and support body 2 erects on boiler 1, and support body 2 is vertical setting, and the welding of 2 upper ends of support body has and is vertical jar 3 that holds, holds jar 3 and is located boiler 1's top, holds jar 3 and is hollow cylinder setting. The inner walls of two sides of the holding tank 3 are respectively welded with a horizontal bracket 31, the bracket 31 is welded with a vertical fly ash bin 4, the fly ash bin 4 is positioned at the upper end of the inner cavity of the holding tank 3, and the fly ash bin 4 is used for bearing fly ash captured by a dust remover. Hold 3 inner chambers of jar and be located the below in flying ash storehouse 4 and weld through support 31 and be hollow processing storehouse 5, processing storehouse 5 is vertical and be cylindric setting. The lower end of the fly ash bin 4 is welded and communicated with a funnel-shaped ash bin pipe 41, and the lower end of the ash bin pipe 41 is welded and penetrates through the upper end of the treatment bin 5. The inner cavity of the treatment bin 5 is provided with a temperature holding mechanism 6 for keeping the temperature of the fly ash, the lower end of the treatment bin 5 is welded and communicated with a vertical lower ash pipe 51, and the lower end of the lower ash pipe 51 extends out of the accommodating tank 3 and is welded and communicated with the upper end of the boiler 1.

Referring to fig. 2, the temperature-keeping mechanism 6 includes a distribution plate 61 welded to the inner wall of the processing chamber 5, the distribution plate 61 is located at the upper end of the processing chamber 5, the distribution plate 61 is horizontally disposed, the distribution plate 61 is hollow and has a circular cross section, the lower surface of the distribution plate 61 is disposed in an arc shape, and the arc-shaped protrusion of the lower surface of the distribution plate 61 is disposed downward. The lower end of the ash bin pipe 41 penetrates through the inner cavity of the distribution plate 61. The lower surface of the distribution plate 61 is welded with a plurality of spiral communication pipes 62, the upper ends of the communication pipes 62 are communicated with the inner cavity of the distribution plate 61, meanwhile, the communication pipes 62 are arranged along the longitudinal direction in the axial direction, the communication pipes 62 are distributed along the circumferential direction of the distribution plate 61, the lower ends of the communication pipes 62 are provided with valves for discharging fly ash, and then, an interval is reserved between every two adjacent communication pipes 62. Handle 5 inner walls and be located the position welding of lower extreme and be the horizontally and assemble board 63, assemble board 63 and be cavity and the cross-section is circular setting, and 62 lower extremes welding of communicating pipe just wears to locate and assembles board 63 upper surface, assembles board 63 lower surface simultaneously and is the arc setting, assembles the arc arch of board 63 lower surface and sets up down, and just the welding of ash pipe 51 upper end just wears to locate and assembles board 63 lower surface down.

Referring to fig. 1 and 2, a closed chamber 64 is formed between the distribution plate 61, the convergence plate 63, and the inner wall of the processing chamber 5, and the frame body 2 is provided with a heat supply assembly 65 for transferring a heat source to the closed chamber 64. Heat supply assembly 65 is including fixed mounting in the hot water supply tank 651 of support body 2, and hot water supply tank 651 is the cavity setting, and the hot water supply tank 651 is interior to contain the water pump, and the hot water supply tank 651 inner wall is fixed with heater 652 through the clamp, and the welding of hot water supply tank 651 lateral wall and intercommunication have a delivery pipe 653, and delivery pipe 653 deviates from the one end of hot water supply tank 651 and wears to locate holding tank 3 and welding and communicates in the position department that processing storehouse 5 is located closed chamber 64. The treatment cabin 5 is welded and communicated with a circulating pipe 654 at the position of the closed chamber 64, the circulating pipe 654 is arranged at one side of the treatment cabin 5 departing from the water supply pipe 653, one end of the circulating pipe 654 departing from the treatment cabin 5 extends out of the side wall of the holding tank 3 and is fixed and communicated with the hot water supply tank 651, and then the circulating pipe 654 is flush with the pipe orifice of the water supply pipe 653 in height.

Referring to fig. 3, a plurality of vertical springs 66 are welded on the upper surface of the convergence plate 63, the springs 66 are disposed between two adjacent communication pipes 62, the lower ends of the springs 66 are welded on the convergence plate 63, rubber balls 67 are bonded on the upper ends of the springs 66, the rubber balls 67 are flush with the pipe orifice of the water supply pipe 653, and the springs 66 are soft springs, but the rubber balls 67 are not subjected to external force, the springs 66 are kept in a vertical state, when hot water flows into the closed chamber 64 of the treatment bin 5 from the water supply pipe 653, water flow can impact on the rubber balls 67, the rubber balls 67 can swing randomly under the action of the springs 66, so as to accelerate the flowing and mixing of the hot water in the treatment bin 5, and meanwhile, the rubber balls 67 can impact on the communication pipes 62 randomly, so that the communication pipes 62 vibrate, and prevent fly ash from accumulating on the inner walls of the communication pipes 62, thereby enabling the fly ash to fall down smoothly.

Referring to fig. 3 and 4, in order to adjust the temperature in the closed chamber 64 in time and control the temperature of water, thereby controlling the temperature of the fly ash entering the boiler 1, and further assisting in controlling the temperature in the furnace of the boiler 1, the temperature adjusting mechanism 7 is fixedly installed on the inner wall of the treatment bin 5, and the temperature adjusting mechanism 7 comprises a temperature sensor 71, a comparison circuit 72 and a control circuit 73. The temperature sensor 71 is a positive coefficient sensor, and the temperature sensor 71 is fixedly mounted on the inner wall of the closed chamber 64 of the treatment bin 5 and used for detecting the temperature of water in the closed chamber 64 in real time and outputting a temperature detection signal.

Referring to fig. 4, the comparison circuit 72 includes a comparator a and a reference circuit including a first resistor R1 and a second resistor R2 for setting a temperature reference value. The inverting input terminal of the comparator a is connected to the output terminal of the temperature sensor 71, and the non-inverting input terminal of the comparator a is connected to the first resistor R1; one end of the first resistor R1 is connected to the power supply VCC, and the other end of the first resistor R1 is connected to the non-inverting input terminal of the comparator A; one end of the second resistor R2 is grounded, and the other end of the second resistor R2 is connected to the connection point of the first resistor R1 and the non-inverting input terminal of the comparator a. The comparator A receives the temperature detection signal, converts the temperature detection signal into a corresponding temperature detection value in real time, compares the temperature detection value with a temperature reference value, and outputs a high level when the temperature detection value is smaller than the temperature reference value.

Referring to fig. 4, the control circuit 73 includes a transistor Q, a relay KM, and a freewheeling diode D; the triode Q is an NPN type triode, the base electrode of the triode Q is connected with the output end of the comparator A, and the emitting electrode of the triode Q is grounded. The relay KM comprises a coil and a normally open contact KM-1, one end of the coil is connected with a collector of the triode Q, the other end of the coil is connected with a power supply VCC, and the normally open contact KM-1 is connected in series in a power supply loop of the heater 652. The anode of the freewheeling diode D is connected between the coil and the collector of the triode Q, and the cathode of the freewheeling diode D is connected between the coil and the power supply VCC. When the comparator A outputs high level, the triode Q is conducted, the coil of the relay KM is electrified, and the normally open contact KM-1 is closed.

The implementation principle of the embodiment of the application is as follows: the dust collector sends the captured fly ash to the fly ash bin 4, when the fly ash enters the fly ash bin 4, the temperature is high, so that the temperature of the whole fly ash bin 4 is high, at the moment, the fly ash bin 4 can transmit heat to the treatment bin 5, meanwhile, the fly ash in the fly ash bin 4 falls into the distribution plate 61 through the ash bin pipe 41 and falls into each communication pipe 62 from the distribution plate 61, so that the fly ash is stored in the communication pipe 62, water flows into the closed chamber 64 from the water supply pipe 653, meanwhile, the temperature sensor 71 in the closed chamber 64 can detect the water temperature in real time, when the water temperature is lower than a preset temperature reference value, the comparator A outputs a high level, the relay KM is electrified, the normally open contact KM-1 is closed, the heating pipe is automatically opened, the water is continuously heated, the hot water transmits the heat to the fly ash in the communication pipe 62, so that the fly ash keeps high temperature, the hot water circulates, when the fly ash is required to be added into the boiler 1, the valve is opened, the fly ash in the communicating pipe 62 falls into the convergence plate 63 and then falls into the boiler 1 through the ash discharging pipe 51 for circulating combustion.

The above embodiments are preferred embodiments of the present application, and the protection scope of the present application is not limited by the above embodiments, so: equivalent changes in structure, shape and principle of the present application shall be covered by the protection scope of the present application.

Claims

1. The utility model provides a fluidized bed boiler flying dust recycling system, includes flying dust storehouse (4), boiler (1), its characterized in that: the fly ash treatment device is characterized by further comprising a frame body (2) erected above the boiler (1), wherein the frame body (2) is fixedly connected with a hollow accommodating tank (3), the fly ash bin (4) is arranged at the upper end of the inner cavity of the accommodating tank (3), a hollow treatment bin (5) is arranged in the inner cavity of the accommodating tank (3) and below the fly ash bin (4), the lower end of the fly ash bin (4) is fixedly communicated with an ash bin pipe (41), the ash bin pipe (41) is fixedly arranged at the upper end of the treatment bin (5) in a penetrating manner, a temperature maintaining mechanism (6) for maintaining the temperature of fly ash is arranged in the inner cavity of the treatment bin (5), a lower ash pipe (51) is fixedly arranged at the lower end of the treatment bin (5) in a penetrating manner, and is fixedly communicated with the boiler (1); the temperature holding mechanism (6) comprises a distribution plate (61) fixedly connected to the inner wall of the treatment bin (5), the distribution plate (61) is located at the upper end of the treatment bin (5), the distribution plate (61) is arranged in a hollow mode, a hollow convergence plate (63) is fixedly connected to the lower end of the inner wall of the treatment bin (5), a closed chamber (64) is formed between the distribution plate (61) and the inner wall of the treatment bin (5), a plurality of communicating pipes (62) are fixedly and communicated between the distribution plate (61) and the convergence plate (63), the ash bin pipe (41) penetrates through the inner cavity of the distribution plate (61), the ash discharging pipe (51) is fixedly and communicated with the lower end of the convergence plate (63), a valve is arranged on each communicating pipe (62), and the frame body (2) is provided with a heat supply assembly (65) for conveying a heat source to the closed chamber (64); the heat supply assembly (65) comprises a hot water supply tank (651) arranged on the frame body (2), the hot water supply tank (651) is arranged in a hollow mode, a heater (652) is fixedly connected to the inner wall of the hot water supply tank (651), a water supply pipe (653) is fixedly connected to the hot water supply tank (651), the water supply pipe (653) is fixedly connected to the position, located in the closed chamber (64), of the treatment bin (5), a circulating pipe (654) is fixedly connected to the position, located in the closed chamber (64), of the treatment bin (5), the circulating pipe (654) is arranged on one side, away from the water supply pipe (653), of the treatment bin (5), and the circulating pipe (654) is fixedly connected to the hot water supply tank (651); the upper surface of the convergence plate (63) is fixedly connected with a plurality of springs (66), the springs (66) are located between two adjacent communicating pipes (62), one ends of the springs (66) are fixedly connected to the convergence plate (63), the other ends of the springs (66) are fixedly connected with rubber balls (67), and the rubber balls (67) are flush with the pipe orifice of the water supply pipe (653).

2. A fluidized bed boiler fly ash recirculation system according to claim 1, characterized in that: the lower surface of the distributing plate (61) is arranged in an arc shape, the arc-shaped bulges on the lower surface of the distributing plate (61) are arranged towards the communicating pipe (62), the lower surface of the converging plate (63) is arranged in an arc shape, and the arc-shaped bulges on the lower surface of the converging plate (63) are arranged towards the lower ash pipe (51).

3. A fluidized bed boiler fly ash recirculation system according to claim 2, characterized in that: handle storehouse (5) inner wall and be provided with temperature adjusting mechanism (7), temperature adjusting mechanism (7) include:

the temperature sensor (71) is arranged on the inner wall of the processing bin (5) and is positioned at the position of the closed chamber (64) and used for detecting the temperature of hot water in the closed chamber (64) of the processing bin (5) and outputting a temperature detection signal;

the comparison circuit (72) is preset with a temperature reference value, is connected with the output end of the temperature sensor (71), receives the temperature detection signal and outputs a comparison signal; and the number of the first and second groups,

and the control circuit (73) is connected with the output end of the comparison circuit (72), is connected with the heater (652), receives the comparison signal and outputs a control signal for controlling the on-off of the heater (652) based on the comparison signal.

4. A fluidized bed boiler fly ash recirculation system according to claim 3, wherein: the comparison circuit (72) comprises a comparator A, a reference circuit, the reference circuit comprises a first resistor R1 and a second resistor R2, and the reference circuit is used for setting a temperature reference value;

the positive phase input end of the comparator A is connected with the first resistor R1, and the negative phase input end of the comparator A is connected with the output end of the temperature sensor (71);

5. A fluidized bed boiler fly ash recirculation system according to claim 4, characterized in that: the control circuit (73) comprises a triode Q, a relay KM and a freewheeling diode D; wherein the content of the first and second substances,

the relay KM comprises a coil and a normally open contact KM-1, one end of the coil is connected with a collector of the triode Q, the other end of the coil is connected with a power supply VCC, and the normally open contact KM-1 is connected in a power supply loop of the heater (652);

6. A fluidized bed boiler fly ash recirculation system according to claim 1, characterized in that: the communicating pipe (62) is spirally arranged.