System for drying household garbage by using flue gas waste heat of coal-fired boiler

Abstract

The utility model provides a system for drying household garbage by using flue gas waste heat of a coal-fired boiler, which is characterized in that an inlet of a garbage rotary drying device in the system is connected with a tail flue of an air pre-heater, and an outlet of the garbage rotary drying device is connected with a front flue of an induced draft fan; wet household garbage in the garbage rotary drying device is dried through waste heat of waste smoke led out from the tail of the air pre-heater, and the waste smoke after heat exchange carries garbage water vapor to enter the desulfurization device to be purified under the traction of the induced draft fan. According to the system, the drying process of the household garbage is coupled with the coal-fired boiler, on one hand, recycling of flue gas waste heat of the coal-fired boiler can be improved, and energy waste is reduced; and on the other hand, drying treatment of the household garbage can be achieved, the garbage rotary drying device operates under the negative pressure condition by means of the pressure difference between different devices of the coal-fired boiler, and leakage of peculiar smells of the garbage is avoided. According to the system, by means of a tail gas purification system of the coal-fired boiler, efficient co-treatment of garbage drying tail gas can be achieved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the field of coal-fired boiler energy recovery technology, and specifically relates to a system for drying household garbage by using flue gas waste heat of a coal-fired boiler. BACKGROUND

[0002] Compared with disposal methods such as landfill, incineration, and biological fermentation, pyrolysis gasification can convert the complex and variable unstable solid renewable energy of household garbage into high-quality combustible gas, but the high water content restricts the implementation of the gasification process. Under the new type of power structure of low-carbon power generation and coal power unit flexible peak shaving, coal-fired boilers urgently need to mix green hydrogen / green ammonia, biomass, and other renewable energy for deep peak shaving and carbon reduction, and the preparation of green hydrogen from household garbage to assist the efficient power generation of coal-fired boilers has become a new trend in the industry.

[0003] A large amount of flue gas waste heat is generated during the operation of a coal-fired boiler, and this waste heat is often not fully utilized, resulting in energy waste.

[0004] Therefore, the utility model provides a system for drying household garbage by using flue gas waste heat of a coal-fired boiler. UTILITY MODEL CONTENTS

[0005] The utility model aims to solve one of the technical problems in the prior art, and provides a system for drying household garbage by using flue gas waste heat of a coal-fired boiler.

[0006] The utility model provides a system for drying household garbage by using flue gas waste heat of a coal-fired boiler, which comprises a boiler main body, a denitration device, an air preheater, a dust removal device, an induced draft fan, a desulfurization device, and a garbage rotary drying device.

[0007] The boiler main body, the denitration device, the air preheater, the dust removal device, the induced draft fan, and the desulfurization device are connected in sequence.

[0008] The inlet of the garbage rotary drying device is connected with the tail flue of the air preheater, and the outlet of the garbage rotary drying device is connected with the front flue of the induced draft fan.

[0009] Optionally, the garbage rotary drying device operates under negative pressure conditions to prevent the emission of odor gas.

[0010] Optionally, the system further comprises a dry garbage storage, which is connected with the outlet of the garbage rotary drying device and is used for storing the dried household garbage.

[0011] Optionally, the system further comprises a garbage lifting device.

[0012] The outlet of the garbage lifting device is connected with the inlet of the garbage rotary drying device.

[0013] Optionally, the system also includes a wet waste storage area;

[0014] The outlet of the wet waste storage is connected to the inlet of the waste lifting and transporting device.

[0015] Optionally, the system may also include a chimney connected to the desulfurization unit.

[0016] Optionally, the waste rotary drying device includes a segmented variable diameter drum assembly;

[0017] The segmented variable diameter roller assembly includes a front cylindrical section and a rear tapered conical section connected to the front cylindrical section; wherein...

[0018] The inner diameter of the front cylindrical section is 1.2 to 1.5 times the diameter of the inlet end of the rear tapered conical section.

[0019] Optionally, the waste rotary drying device further includes an anti-corrosion layer, which is disposed on the inner sidewall of the front cylindrical section and the rear tapered conical section.

[0020] Optionally, the anti-corrosion layer is an Al2O3-TiO2 composite ceramic layer.

[0021] Optionally, the waste rotary dryer also includes a variable frequency speed control drive structure;

[0022] The variable frequency speed control drive structure is used to dynamically adjust the rotational speed range of the segmented variable diameter roller assembly from 0.5 r / min to 2.5 r / min.

[0023] The variable frequency speed control drive structure is also used to control the residence time of domestic waste within a range of 30 minutes to 90 minutes with stepless adjustment.

[0024] This invention provides a system for drying municipal solid waste using waste heat from a coal-fired boiler. In this system, the inlet of a rotary waste dryer is connected to the tail flue of an air preheater, and the outlet is connected to the front flue of an induced draft fan. The waste heat from the exhaust gas drawn from the tail of the air preheater is used to dry the wet municipal solid waste. The heat-exchanged exhaust gas, carrying moisture from the waste, is drawn into a desulfurization unit by the induced draft fan for purification. This system couples the municipal solid waste drying process with the coal-fired boiler, improving the recovery and utilization of waste heat and reducing energy waste. It also enables the drying and disposal of municipal solid waste, and utilizes the pressure difference between different components of the coal-fired boiler to allow the rotary waste dryer to operate under negative pressure, preventing the leakage of odors. Furthermore, the system leverages the boiler's built-in exhaust gas purification system to achieve efficient and coordinated treatment of the waste drying exhaust gas. Attached Figure Description

[0025] Figure 1The utility model discloses a kind of system for drying domestic waste by using flue gas waste heat of coal-fired boiler for an embodiment of the utility model. DETAILED DESCRIPTION

[0026] In order to make those skilled in the art better understand the technical scheme of the utility model, the utility model is further described in detail below with reference to the drawings and specific embodiments.

[0027] As Figure 1 shown, the utility model provides a kind of system for drying domestic waste by using flue gas waste heat of coal-fired boiler, including coal-fired boiler subsystem and domestic waste drying subsystem.

[0028] The coal-fired boiler subsystem includes sequentially connected boiler main body 1, denitration device 2, air preheater 3, dust removal device 4, induced draft fan 5, desulfurization device 6 and chimney 7.

[0029] The domestic waste drying subsystem includes garbage rotary drying device 8, the inlet of the garbage rotary drying device 8 is connected with the tail flue of the air preheater 3, and the outlet of the garbage rotary drying device 8 is connected with the front flue of the induced draft fan 5.

[0030] Among them, a stream of waste flue gas is led out from the tail flue of the air preheater 3 to enter the garbage rotary drying device 8 to dry wet domestic waste in the rotary drying device 8 by using the waste flue gas waste heat, and the waste flue gas carrying waste water vapor after heat exchange enters the desulfurization device 6 for purification treatment under the traction of the induced draft fan 5 and is discharged through the chimney 7.

[0031] Specifically, in the normal operation process of power plant coal-fired boiler, the tail hot flue gas of boiler main body 1 is first introduced into denitration device 2 under the traction of induced draft fan 5, and heat exchange is carried out at air preheater 3, at which time the flue gas temperature decreases from about 310 ℃ at the inlet to about 140 ℃ at the outlet. The flue gas after heat exchange is first introduced into dust removal device 4 for particle removal, then introduced into desulfurization device 6 for spray desulfurization, and finally introduced into chimney 7 to be discharged into the atmosphere. The heat source for drying domestic waste comes from the waste flue gas (about 140 ℃) at the outlet of air preheater 3, and a stream of bypass flue gas is led out from the tail flue of air preheater 3 to pass through garbage rotary drying device 8 to realize the drying disposal of wet domestic waste, and the waste flue gas carrying waste water vapor after heat exchange enters the desulfurization device 6 under the traction of the induced draft fan 5 to realize the purification disposal of waste flue gas and waste water vapor, and finally the tail gas is discharged into the chimney 7.

[0032] The system for drying household garbage by using flue gas waste heat of a coal-fired boiler couples the drying process of the household garbage with the coal-fired boiler, on the one hand, can improve the recycling of the flue gas waste heat of the coal-fired boiler, and reduce energy waste; on the other hand, can realize the drying disposal of the household garbage, and utilize the pressure difference between different devices of the coal-fired boiler, so that the garbage rotary drying device operates under negative pressure condition, and the leakage of peculiar smell of the garbage is avoided. The system can realize the efficient and collaborative disposal of the drying tail gas of the garbage by the tail gas purification system of the coal-fired boiler.

[0033] Exemplarily, the garbage rotary drying device 8 operates under negative pressure condition to prevent peculiar smell gas from leaking out.

[0034] Specifically, the outlet negative pressure of the air preheater 3 is about -2000Pa to -3000Pa, the inlet negative pressure of the induced draft fan 5 is about -2500Pa to -3500Pa, and the pressure difference between the two is about 500Pa to 1000Pa, so that the garbage rotary drying device 8 operates under negative pressure condition and peculiar smell gas does not leak out.

[0035] In the embodiment, the pressure difference between the air preheater and the induced draft fan of the coal-fired boiler is utilized to make the garbage rotary drying device operate under negative pressure condition, so that the leakage of peculiar smell of the garbage is avoided.

[0036] Exemplarily, as shown in Figure 1 The household garbage drying subsystem further comprises a dry garbage storage 9 connected with the outlet of the garbage rotary drying device 8, and used for storing the dried household garbage.

[0037] Exemplarily, as shown in Figure 1 The household garbage drying subsystem further comprises a garbage conveying device 10 and a wet garbage storage 11. The inlet of the garbage conveying device 10 is connected with the wet garbage storage 11, and the outlet of the garbage conveying device 10 is connected with the inlet of the garbage rotary drying device 8.

[0038] Specifically, the household garbage is first collected and transported to a garbage collection station, and after preliminary sorting and compression dewatering forming, is finally transported to a coal-fired power plant. The household garbage transported to the power plant is first stored in the wet garbage storage 11, and then enters the garbage rotary drying device 8 by means of transportation and the garbage conveying device 10 to perform drying operation, and at this time, the moisture content of the garbage can be finally reduced to about 10%. The dried household garbage is transported to the dry garbage storage 9 for standby.

[0039] Exemplarily, the garbage rotary drying device 8 comprises a segmented variable-diameter roller assembly; the segmented variable-diameter roller assembly comprises a front cylinder segment and a rear tapered cone cylinder segment connected with the front cylinder segment; wherein the inner diameter of the front cylinder segment is 1.2 to 1.5 times the diameter of the inlet end of the rear tapered cone cylinder segment.

[0040] For example, the waste rotary dryer 8 further includes an anti-corrosion layer, which is disposed on the inner wall of the front cylindrical section and the rear tapered conical section. The anti-corrosion layer mitigates the corrosive effect of leachate on the inner wall of the segmented variable-diameter drum assembly.

[0041] Preferably, in this embodiment, the anti-corrosion layer is an Al2O3-TiO2 composite ceramic layer. The Al2O3-TiO2 composite ceramic layer can withstand the Cl- in landfill leachate. - SO4 2- corrosion.

[0042] For example, the waste rotary drying device further includes a variable frequency speed control drive structure; the variable frequency speed control drive structure is used to dynamically adjust the rotational speed of the segmented variable diameter roller assembly within the range of 0.5 r / min to 2.5 r / min according to the initial moisture content of the waste (20%-50%). The variable frequency speed control drive structure is also used to control the residence time of domestic waste within a stepless range of 30 minutes to 90 minutes.

[0043] The waste rotary dryer also includes a spiral guide plate arranged along the axial direction of the drum, which pushes the waste toward the outlet and forms an axial vortex, extending the residence time of the hot flue gas.

[0044] The method for drying municipal solid waste using the waste heat from coal-fired boiler flue gas in this embodiment is as follows:

[0045] First, the waste heat from the exhaust gas drawn from the tail flue of the air preheater 3 is used to dry the wet domestic waste in the rotary waste dryer 8.

[0046] Secondly, the waste flue gas after heat exchange, carrying the water vapor from the garbage, enters the desulfurization device 6 under the traction of the induced draft fan 5 for purification treatment, and is finally discharged through the chimney 7.

[0047] Specifically, the waste heat of the flue gas drawn from the tail flue of the air preheater 3 is used to dry the wet domestic waste in the rotary dryer 8. The waste gas after heat exchange, carrying the water vapor from the waste, enters the desulfurization device 6 for purification under the traction of the induced draft fan 5, and is discharged through the chimney 7.

[0048] The method for drying household garbage by using flue gas waste heat of a coal-fired boiler couples the drying process of the household garbage with the coal-fired boiler, on the one hand, can improve the recycling of the flue gas waste heat of the coal-fired boiler, and reduce energy waste; on the other hand, can realize the drying disposal of the household garbage, and utilize the pressure difference between different devices of the coal-fired boiler, so that the garbage rotary drying device operates under negative pressure condition, and the leakage of peculiar smell of the garbage is avoided. The method can realize the efficient and collaborative disposal of the garbage drying tail gas by means of the tail gas purification system of the coal-fired boiler.

[0049] It can be understood that the above embodiments are only exemplary embodiments for illustrating the principles of the present application, but the present application is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present application, and these modifications and improvements are also considered as the protection scope of the present application.

Claims

1. A system for drying domestic waste by using the waste heat of flue gas of a coal-fired boiler, characterized in that, The system comprises a boiler body, a denitration device, an air preheater, a dust removal device, an induced draft fan, a desulfurization device and a garbage rotary drying device. The boiler body, the denitration device, the air preheater, the dust removal device, the induced draft fan and the desulfurization device are sequentially connected. The inlet of the garbage rotary drying device is connected with the tail flue of the air preheater, and the outlet of the garbage rotary drying device is connected with the front flue of the induced draft fan.

2. The system of claim 1, wherein, The garbage rotary drying device operates under negative pressure to prevent the emission of odor smoke.

3. The system of claim 1, wherein, The system further comprises a dry garbage storage connected with the outlet of the garbage rotary drying device for storing dried household garbage.

4. The system according to any one of claims 1 to 3, characterized in that, The system further comprises a garbage lifting device. The outlet of the garbage lifting device is connected with the inlet of the garbage rotary drying device.

5. The system of claim 4, wherein, The system further comprises a wet garbage storage. The outlet of the wet garbage storage is connected with the inlet of the garbage lifting device.

6. The system of any one of claims 1 to 3, wherein, The system further comprises a chimney connected with the desulfurization device.

7. The system of any one of claims 1 to 3, wherein, The garbage rotary drying device comprises a segmented variable-diameter roller assembly. The segmented variable-diameter roller assembly comprises a front cylindrical segment and a rear tapered conical segment connected with the front cylindrical segment. The inner diameter of the front cylindrical segment is 1.2 to 1.5 times the diameter of the inlet end of the rear tapered conical segment.

8. The system of claim 7, wherein, The garbage rotary drying device further comprises an anti-corrosion layer arranged on the inner side walls of the front cylindrical segment and the rear tapered conical segment.

9. The system of claim 8, wherein, The anti-corrosion layer is an Al2O3-TiO2 composite ceramic layer.

10. The system of claim 7, wherein, The garbage rotary drying device further comprises a variable-frequency speed regulation driving structure. The variable-frequency speed regulation driving structure is used to dynamically adjust the rotation speed range of the segmented variable-diameter roller assembly to 0.5 r / min to 2.5 r / min. The variable-frequency speed regulation driving structure is also used to control the stepless regulation of the residence time of household garbage to 30 minutes to 90 minutes.

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