System and method for heat utilization of flue gas of waste incineration plant

Abstract

The present application relates to waste incineration processing technical field, especially to waste power plant incinerator flue gas heat utilization system and method, system includes successively connected incinerator unit, flue unit and flue gas treatment and discharge unit;The incinerator unit includes drying section grate, combustion section grate and afterburning section grate;The flue unit includes first flue and second flue, second flue is set in the front of first flue, the smoke outlet of first flue is communicated with the smoke inlet of second flue, the smoke outlet of second flue is communicated with flue gas treatment and discharge unit, and the lower end ash outlet of second flue is set above drying section grate.The present application adopts the second flue to be placed in the front of first flue, makes the flue gas generated by garbage combustion flow upward and forward in reverse, increases the contact area of flue gas and boiler water cooling wall to improve heating efficiency, and the high-heat fly ash generated by second flue is sent to drying section grate to preheat garbage, so that the flue gas heat generated can be reused.

Description

TECHNICAL FIELD

[0001] The present application relates to waste incineration processing technical field, especially to waste power plant incinerator flue gas heat utilization system and method. BACKGROUND

[0002] With the development of urbanization in China and the continuous improvement of people's living standards, the amount of urban waste is also increasing. At present, waste incineration power generation is becoming more and more popular. The heat generated after waste incineration is absorbed by the waste heat boiler to generate steam to drive the steam turbine to generate power. The waste power boiler usually has small capacity and low parameters, and has the problem of low power generation efficiency.

[0003] The traditional waste power boiler incinerates waste, and the flue gas direction is from the front to the back of the furnace. The second flue is arranged behind the first flue. The high-heat fly ash generated by the second flue reaches the slag outlet through the ash discharge pipe, causing heat loss. The flue gas of the traditional waste furnace flows from front to back, and the heat of the fly ash generated by the second flue cannot be utilized, resulting in great waste. SUMMARY

[0004] In order to overcome the shortcomings of the prior art, the purpose of the present application is to provide a waste power plant incinerator flue gas heat utilization system and method, which can improve the heating efficiency of waste and make the generated flue gas heat be utilized twice, greatly saving the cost.

[0005] In order to achieve the above-mentioned purpose, the present application provides the following technical scheme:

[0006] The waste power plant incinerator flue gas heat utilization system comprises a waste incinerator unit, a flue unit and a flue gas treatment and discharge unit connected in sequence. The waste incinerator unit comprises a drying section grate, a combustion section grate and a burnout section grate. The flue unit comprises a first flue and a second flue. The inlet of the first flue is communicated with the combustion section grate. The second flue is arranged in front of the first flue. The outlet of the first flue is communicated with the inlet of the second flue. The outlet of the second flue is communicated with the flue gas treatment and discharge unit. The ash outlet at the lower end of the second flue is arranged above the drying section grate.

[0007] As a preferred scheme of the waste power plant incinerator flue gas heat utilization system, the outlet of the first flue is provided with a dust falling inclined plate.

[0008] As a preferred scheme of the waste power plant incinerator flue gas heat utilization system, the dust falling inclined plate is arranged in an inclined shape with the front low and the back high. The front end of the dust falling inclined plate extends into the second flue, and the rear end of the dust falling inclined plate extends to the flue gas treatment and discharge unit. The flue gas is blocked and turned by the dust falling inclined plate, which can effectively reduce the inclusion of fly ash and reduce the amount of accumulated ash at the rear.

[0009] As a preferred scheme of the garbage power plant incinerator flue gas heat utilization system, the included angle between the ash falling inclined plate and the horizontal plane is 20-30º.

[0010] As a preferred scheme of the garbage power plant incinerator flue gas heat utilization system, the rear of the first flue is provided with a third flue, the smoke inlet of the third flue is communicated with the smoke outlet of the second flue, the smoke outlet of the third flue is communicated with the flue gas treatment and discharge unit, and the second cyclone separation unit is arranged in the third flue. The remaining fly ash in the flue gas falls into the third flue, so that the separation efficiency of the fly ash can be effectively improved, and the fly ash entering the flue gas treatment and discharge unit is greatly reduced.

[0011] As a preferred scheme of the garbage power plant incinerator flue gas heat utilization system, the first cyclone separation unit is arranged in the second flue.

[0012] As a preferred scheme of the garbage power plant incinerator flue gas heat utilization system, the first cyclone separation unit comprises a cyclone volute inlet, a cyclone outlet, a circular cylinder, a circular cone and an ash bucket. The cyclone volute inlet comprises an inlet flange, an inlet short pipe, a square-to-circle and a square inlet which are coaxially connected in sequence, and the square inlet is communicated with the top side volute of the circular cylinder in a tangential manner.

[0013] As a preferred scheme of the garbage power plant incinerator flue gas heat utilization system, a flow guide assembly is arranged in the inlet short pipe, and the flow guide assembly comprises a support, an inner rod and a plurality of flow guide vanes arranged between the support and the inner rod.

[0014] As a preferred scheme of the garbage power plant incinerator flue gas heat utilization system, the lower end of the second flue is provided with a feeding pipe, and the feeding pipe is communicated with the drying section grate. The feeding pipe comprises an outer pipe and an inner sleeve pipe, and the lower end of the feeding pipe is provided as a horn-shaped pipe.

[0015] As a preferred scheme of the garbage power plant incinerator flue gas heat utilization system, a temperature sensor is arranged at the lower end of the feeding pipe. The temperature sensor can effectively prevent the generation of accumulated ash.

[0016] As a preferred scheme of the garbage power plant incinerator flue gas heat utilization system, the drying section grate, the combustion section grate and the burnout section grate are all arranged in an inclined manner with the front end being higher than the rear end and arranged in sequence from front to rear, the rear end of the drying section grate is higher than the front end of the combustion section grate, and the rear end of the combustion section grate is higher than the front end of the burnout section grate. During the movement of the grates, the material is turned over, so that the fly ash does not cover the garbage in the furnace.

[0017] As a preferred scheme of the garbage power plant incinerator flue gas heat utilization system, the flue gas treatment and discharge unit comprises a flue gas purification subunit, an induced draft subunit and a chimney connected in sequence.

[0018] As a preferred scheme of the garbage power plant incinerator flue gas heat utilization system, the incinerator unit is provided with a garbage feeding unit and an air supply unit at the front end.

[0019] The working principle of the present application is that the second flue is arranged in front of the first flue, so that the flue gas generated by garbage combustion flows reversely upward and forward, which not only increases the contact area of the flue gas and the boiler water wall, improves the heating efficiency, but also sends the high-heat fly ash generated by the second flue to the preheating section of the boiler combustion to preheat the garbage, so that the generated flue gas heat can be reused twice, thereby saving the cost.

[0020] A garbage power plant incinerator flue gas heat utilization method, comprising the following steps:

[0021] (1) first, the garbage is delivered to the drying section grate of the incinerator unit, and after preheating and drying in the drying section grate, the garbage enters the combustion section grate for incineration, and the flue gas generated after incineration is discharged upward along the first flue, and part of the fly ash falls into the combustion section grate for continuous incineration;

[0022] (2) the flue gas above the first flue is blocked by the fly ash inclined plate and enters the second flue arranged in front of the first flue reversely and forwardly, the flue gas is discharged backward after passing through the second flue, and most of the fly ash falls into the drying section grate along the lower end of the second flue to preheat and dry the garbage;

[0023] (3) the flue gas generated after the treatment of the second flue is discharged backward into the third flue, the flue gas treated by the third flue is discharged into the treatment and discharge unit, and the flue gas treated by the treatment and discharge unit to reach the discharge condition is discharged outward.

[0024] As a preferred scheme of the garbage power plant incinerator flue gas heat utilization system, the second flue is provided with a first cyclone separation unit, the fly ash falls into the drying section grate after the flue gas is separated by the first cyclone separation unit in the second flue; the third flue is provided with a second cyclone separation unit, and the remaining fly ash falls into the lower part of the third flue after the flue gas is separated by the second cyclone separation unit.

[0025] Compared with the prior art, the present application has the following advantages:

[0026] (1) the second flue is arranged in front of the first flue, the smoke generated by waste combustion flows upwards and forwards reversely, the contact area of the smoke and the boiler water cooling wall can be increased, the heating efficiency is improved, the high-heat fly ash generated by the second flue is sent to the preheating section of the boiler combustion, the waste is preheated, the heat of the generated smoke can be reused, and the cost can be saved;

[0027] (2) the grate of the incinerator is turned over during movement, and fly ash cannot cover the furnace waste;

[0028] (3) the first flue is provided with a fly ash falling inclined plate, the smoke is blocked upwards by the fly ash falling inclined plate, the fly ash can be effectively reduced, and the amount of fly ash in the rear part is reduced;

[0029] (4) a third flue is arranged at the rear of the first flue, so that the remaining fly ash in the smoke falls into the third flue, and the fly ash entering the smoke treatment and discharge unit is greatly reduced;

[0030] (5) the second flue and the third flue are both provided with a cyclone separation unit, so that the separation efficiency of fly ash can be effectively improved;

[0031] (6) a temperature sensor is arranged at the lower end of the second flue, so that the generation of fly ash can be effectively prevented;

[0032] (7) the second flue is provided with an inner and outer pipe and a horn shape, so that the heat of fly ash can be maintained, and the waste on the grate of the drying section can be fully preheated. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the drawings needed in the specific embodiments or the prior art description will be briefly introduced below, and obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor. Among them:

[0034] Figure 1 It is a schematic diagram of the overall structure of the present application;

[0035] Figure 2 It is a schematic diagram of the cyclone separation unit structure of the present application;

[0036] Figure 3 It is a schematic diagram of the flow guide assembly structure of the present application;

[0037] Figure 4 It is a schematic diagram of the overall structure of the second embodiment of the present application;

[0038] The figure reference: 1, incinerator unit; 2, flue unit, 3, flue gas treatment and discharge unit, 4, ash chute, 5, second cyclone separation unit, 6, first cyclone separation unit, 7, flow guide assembly, 11, drying section grate, 12, combustion section grate, 13, burnout section grate, 21, first flue, 22, second flue, 23, third flue; 221, feeding pipe, 61, cyclone volute inlet, 62, cyclone outlet, 63, circular cylinder, 64, circular cone, 65 ash hopper, 611, inlet flange, 612, inlet short pipe, 613, square-to-round, 614, square inlet, 71, bracket, 72, inner rod, 73 flow guide vane. DETAILED DESCRIPTION

[0039] The preferred embodiments of the present application are described below in conjunction with the accompanying drawings, it should be understood that the preferred embodiments described here are only used to illustrate and explain the present application, and are not used to limit the present application. EMBODIMENT

[0040] REFERENCE Figure 1 For the first embodiment of the present application, the embodiment provides a kind of garbage power plant incinerator flue gas heat utilization system, second flue is placed in front of first flue, make the flue gas generated by garbage combustion flow upward and forward in reverse direction, not only can increase the contact area of flue gas and boiler water-cooled wall, improve heating efficiency, but also the high heat fly ash generated by second flue is sent to the preheating section of boiler combustion, preheat garbage, so that the flue gas heat generated can be reused, save cost.

[0041] Specifically, it includes sequentially connected incinerator unit 1, flue unit 2 and flue gas treatment and discharge unit 3;The incinerator unit 1 includes drying section grate 11, combustion section grate 12 and burnout section grate 13;Flue unit 2 includes first flue 21 and second flue 22, the flue inlet of first flue 21 is communicated with combustion section grate 12, the second flue 22 is arranged in front of first flue 21, the flue outlet of first flue 21 is communicated with the flue inlet of second flue 22, the flue outlet of second flue 22 is communicated with flue gas treatment and discharge unit 3, the lower end ash outlet of second flue 22 is arranged above drying section grate 11.

[0042] Preferably, the flue outlet of first flue 21 is provided with ash chute 4;The ash chute 4 is arranged in an inclined manner with the front low and the back high, the front end of ash chute 4 extends into second flue 22, and the rear end of ash chute 4 extends to flue gas treatment and discharge unit 3. The included angle between ash chute 4 and horizontal plane is 20-30º. The flue gas is blocked and turned upward by ash chute, which can effectively reduce the inclusion of fly ash and reduce the amount of ash accumulation in the rear part.

[0043] REFERENCE Figure 2Preferably, the first cyclone separation unit 6 is arranged in the second flue 22.

[0044] The first cyclone separation unit 6 comprises a cyclone volute inlet 61, a cyclone outlet 62, a circular cylinder 63, a circular cone 64 and a hopper 65. The cyclone volute inlet 61 comprises an inlet flange 611, an inlet short pipe 612, a square-to-circle 613 and a square inlet 614 connected coaxially in sequence. The square inlet 614 is in 180° volute tangential communication with the top side of the circular cylinder 63, realizing 180° tangential air inlet. Since the dust-containing airflow does not start to rotate until reaching the cylinder, compared with the straight-cut cyclone separator of the prior art, the 180° tangential air inlet mode makes the airflow rotate at high speed in the airflow channel formed in the cyclone volute inlet 61 in advance, and then enters the cylinder, thereby providing a pre-separation space for solid particle separation, effectively reducing the fly ash concentration near the outlet side, reducing the dust-carrying amount of short-circuit flow, and significantly improving the separation efficiency of the cyclone separator.

[0045] With reference to Figure 3 The inlet short pipe 612 is provided with a flow guide assembly 7 comprising a bracket 71, an inner rod 72 and a plurality of flow guide vanes 73 arranged between the bracket 71 and the inner rod 72. The plurality of flow guide vanes 73 are uniformly distributed. After the flue gas passes through the flow guide vanes 73, it forms an organized airflow movement around the axis of the inner rod 72, enhancing the strength of the airflow, thereby improving the separation efficiency and reducing energy consumption.

[0046] Preferably, the lower end of the second flue 22 is provided with a lower discharge pipe 221 in communication with the drying section grate 11. The lower discharge pipe 221 comprises an outer pipe and an inner sleeve pipe, and the lower end of the lower discharge pipe 221 is provided as a trumpet-shaped pipe. The lower end of the lower discharge pipe 221 is provided with a temperature sensor. When the lower end of the second flue 22 produces dust accumulation, the temperature sensor senses and sends an alarm, which can effectively prevent dust accumulation.

[0047] Preferably, the drying section grate 11, the combustion section grate 12 and the burnout section grate 13 are all arranged in an inclined manner with the front end higher than the rear end and arranged in sequence from front to rear. The rear end of the drying section grate 11 is higher than the front end of the combustion section grate 12, and the rear end of the combustion section grate 12 is higher than the front end of the burnout section grate 13. During the movement of the grates, the material is turned over, and the fly ash does not cover the furnace waste.

[0048] Preferably, the flue gas treatment and discharge unit 3 comprises a flue gas purification subunit, an induced draft subunit and a chimney connected in sequence. The flue gas purification subunit purifies the flue gas, and the induced draft subunit introduces the purified flue gas into the chimney for discharge.

[0049] Preferably, the incinerator unit 1 is provided with a garbage feeding unit and an air feeding unit at the front end. The garbage feeding unit is used to feed garbage into the incinerator unit, and the air feeding unit is used to feed combustion air into the furnace.

[0050] A garbage power plant incinerator flue gas heat utilization method, comprising the following steps:

[0051] (1) First, the garbage is transported to the drying section grate 11 of the incinerator unit 1, and the garbage is preheated and dried in the drying section grate 11 before entering the combustion section grate 12 for incineration. The flue gas generated after incineration is discharged upwards along the first flue 21, and part of the fly ash falls into the combustion section grate 12 for further incineration.

[0052] (2) The flue gas above the first flue 21 is blocked by the fly ash deflector 4 and enters the second flue 22 arranged in front of the first flue 21 in reverse. After the flue gas passes through the second flue 22, it is discharged backwards. Most of the fly ash falls into the drying section grate 11 along the lower end of the second flue 22. At the same time, the first cyclone separation unit 6 is arranged in the second flue 22. After the flue gas passes through the first cyclone separation unit 6, further fly ash falls into the drying section grate 11 to preheat and dry the garbage.

[0053] In use, the garbage is transported from the garbage feeding unit to the incinerator unit 1. After drying and incineration in the incinerator unit 1, the flue gas is discharged upwards along the first flue 21, and then enters the second flue 22 in reverse after being blocked by the fly ash deflector 4, so as to increase the contact area between the flue gas and the boiler water wall to improve the heating efficiency. The flue gas in the second flue 22 is separated by the first cyclone separation unit 6 and then enters the flue gas purification sub-unit. After that, it is discharged into the chimney through the induced draft unit. At the same time, the high-heat fly ash generated in the second flue 22 is transported to the drying section grate 11 connected to the lower end thereof, and the high-heat fly ash is used to preheat and dry the garbage, so that the flue gas heat can be reused, greatly saving the cost. When the lower end of the downcomer 221 produces accumulated ash that does not fall into the drying section grate 11, the temperature sensor will sense and issue a warning to prevent the accumulated ash from being blocked. The direction of the flue gas in this embodiment is shown by the arrow direction in Figure 1 . Embodiment

[0054] Reference Figure 4 This is the second embodiment of the present application, which is based on the previous embodiment.

[0055] Specifically, the difference between the present application and the previous embodiment is that a waste incineration plant furnace flue gas heat utilization system is additionally provided with a third flue 23 behind the first flue 21, the smoke inlet of the third flue 23 is communicated with the smoke outlet of the second flue 22, and the smoke outlet of the third flue 23 is communicated with the flue gas treatment and discharge unit 3. The second cyclone separation unit 5 is arranged in the third flue 23; the structure of the second cyclone separation unit 5 is the same as that of the first cyclone separation unit 6; after the flue gas enters the third flue 23 and is separated by the second cyclone separation unit 5, the remaining fly ash in the flue gas falls into the third flue below and is discharged, so that the fly ash can be prevented from entering the flue gas treatment and discharge unit.

[0056] A waste incineration plant furnace flue gas heat utilization method comprises the following steps:

[0057] First, the waste is transported from the waste feeding unit to the incinerator unit 1, the flue gas generated after the waste is dried and incinerated in the incinerator unit 1 flows upwards along the first flue 21, reversely enters the second flue 22 after being blocked by the ash falling inclined plate 4 to realize the increase of the contact area between the flue gas and the boiler water wall to improve the heating efficiency, the first cyclone separation unit 6 is arranged in the second flue 22, the flue gas is further separated by the first cyclone separation unit 6, and the fly ash falls into the drying section grate 11 to preheat and dry the waste, the high-heat fly ash is used to preheat and dry the waste, the generated flue gas heat is reused twice, the flue gas in the second flue 22 enters the third flue 23, and the remaining fly ash in the flue gas is further separated by the second cyclone separation unit 5 and falls into the third flue 23 below and is discharged. Finally, the flue gas is treated by the flue gas treatment and discharge unit 3 and is discharged; the present embodiment is provided with three flues, the fly ash in the flue gas can be completely discharged below for secondary utilization, and the fly ash can be prevented from entering the flue gas treatment and discharge unit to increase the treatment procedure; the second flue is arranged in front of the first flue, the flue gas generated by the waste combustion flows upwards and reversely forwards, the contact area between the flue gas and the boiler water wall can be increased, and the heating efficiency can be greatly improved.

[0058] In use, the waste is transported from the waste feeding unit to the incinerator unit 1, the flue gas generated after the waste is dried and incinerated in the incinerator unit 1 flows upwards along the first flue 21, reversely enters the second flue 22 after being blocked by the ash falling inclined plate 4 to realize the increase of the contact area between the flue gas and the boiler water wall to improve the heating efficiency, the flue gas in the second flue 22 enters the third flue 23, and the second cyclone separation unit 5 is arranged in the third flue 23. After the flue gas enters the third flue 23 and is separated by the second cyclone separation unit 5, the remaining fly ash in the flue gas falls into the third flue below and is discharged, the separated flue gas enters the flue gas purification subunit, and then enters the chimney through the induced draft unit and is discharged. The direction of the flue gas in the present embodiment is shown by the arrow direction in Figure 2 .

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit the present application; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacements for part or all of the technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A waste incineration plant furnace flue gas heat utilization system, comprising a furnace unit (1), a flue unit (2) and a flue gas treatment and discharge unit (3) connected in sequence; characterized in that: The incinerator unit (1) comprises a drying section grate (11), a combustion section grate (12) and a burnout section grate (13) arranged in sequence from front to back; the flue unit (2) comprises a first flue (21) and a second flue (22), the smoke inlet of the first flue (21) is communicated with the combustion section grate (12), the second flue (22) is arranged in front of the first flue (21), the smoke outlet of the first flue (21) is communicated with the smoke inlet of the second flue (22), the smoke outlet of the second flue (22) is communicated with the flue gas treatment and discharge unit (3), the lower end ash outlet of the second flue (22) is arranged above the drying section grate (11), the smoke outlet of the first flue (21) is provided with an ash falling inclined plate (4), and the second flue (22) is provided with a first cyclone separation unit (6).

2. The waste incineration plant boiler flue gas heat utilization system according to claim 1, characterized in that: The ash falling inclined plate (4) is arranged in an inclined shape with the front being low and the rear being high, the front end of the ash falling inclined plate (4) extends into the second flue (22), and the rear end of the ash falling inclined plate (4) extends to the flue gas treatment and discharge unit (3).

3. The waste incineration plant boiler flue gas heat utilization system according to claim 2, characterized in that: The rear of the first flue (21) is provided with a third flue (23), the smoke inlet of the third flue (23) is communicated with the smoke outlet of the second flue (22), the smoke outlet of the third flue (23) is communicated with the flue gas treatment and discharge unit (3), and the third flue (23) is provided with a second cyclone separation unit (5).

4. The waste incineration plant boiler flue gas heat utilization system according to claim 3, characterized in that: The first cyclone separation unit (6) comprises a cyclone volute inlet (61), a cyclone outlet (62), a circular cylinder (63), a circular cone (64) and a hopper (65), the cyclone volute inlet (61) comprises an inlet flange (611), an inlet short pipe (612), a square-to-circle (613) and a square inlet (614) which are coaxially connected in sequence, and the square inlet (614) is communicated with the top side volute of the circular cylinder (63) in a tangential manner.

5. The waste incineration plant boiler flue gas heat utilization system according to claim 4, characterized in that: The inlet short pipe (612) is provided with a flow guide assembly (7), and the flow guide assembly (7) comprises a support (71), an inner rod (72) and a plurality of flow guide vanes (73) arranged between the support (71) and the inner rod (72).

6. The waste incineration plant boiler flue gas heat utilization system according to claim 5, characterized in that: The drying section grate (11), the combustion section grate (12) and the burnout section grate (13) are all arranged in an inclined shape with the front being high and the rear being low and arranged in sequence from front to back, the rear end of the drying section grate (11) is higher than the front end of the combustion section grate (12), and the rear end of the combustion section grate (12) is higher than the front end of the burnout section grate (13).

7. A method for heat utilization of flue gas from a waste incineration plant, characterized by: The garbage power plant incinerator flue gas heat utilization system of claim 1 is applied, Comprising the following steps: (1) first, the garbage is transported to the drying section grate (11) of the incinerator unit (1), the garbage is preheated and dried in the drying section grate (11) and then enters the combustion section grate (12) for incineration, and the flue gas generated after incineration is discharged upwards along the first flue (21), and part of the fly ash falls into the combustion section grate (12) for further incineration; (2), the flue gas above the first flue (21) is blocked by the falling ash inclined plate (4) and enters the second flue (22) set in front of the first flue (21) in reverse, the flue gas is discharged backward after passing through the second flue (22), and most of the fly ash falls into the drying section grate (11) to preheat and dry the garbage along the lower end of the second flue (22); (3), the flue gas generated after the second flue (22) is discharged backward into the third flue (23), and the flue gas treated by the third flue (23) is discharged into the treatment and discharge unit (3); after being treated by the treatment and discharge unit (3) to reach the discharge condition, it is discharged outward.

8. The waste incineration plant boiler flue gas heat utilization method according to claim 7, characterized in that: The flue gas in the second flue (22) is separated by the first cyclone separation unit (6), and the fly ash falls into the drying section grate (11); the third flue (23) is provided with a second cyclone separation unit (5), and the remaining fly ash falls into the third flue (23) after the flue gas is separated by the second cyclone separation unit (5).

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