A waste incineration flue gas waste heat recovery and recycling system

Abstract

The utility model relates to a kind of garbage incineration flue gas waste heat recovery and reuse system, including the garbage bin that is sequentially arranged, primary air blower, garbage incinerator, flue gas purification mechanism, induced draft fan and chimney, and waste heat utilization heat exchanger is installed between the garbage bin and the primary air blower, three-way air pipe is installed between the waste heat utilization heat exchanger and the primary air blower, and backflow centrifugal fan is installed in three-way air pipe by pipeline, and the air outlet pipe of backflow centrifugal fan is connected with the garbage bin. By installing backflow centrifugal fan between waste heat utilization heat exchanger and primary air blower, part of the waste gas after heat exchange is transported to garbage bin, the space temperature in garbage bin is improved, the garbage fermentation quality in northern winter season is guaranteed, energy loss is reduced, the storage turnover time is shortened, the garbage calorific value is improved, the operation cost is saved, and the air temperature of primary air is improved by waste heat utilization heat exchanger.

Description

Technical Field

[0001] This utility model relates to the field of flue gas waste heat recovery technology, specifically to a waste incineration flue gas waste heat recovery and reuse system. Background Technology

[0002] In recent years, with the continuous improvement of living standards, the amount of urban domestic waste in my country has increased rapidly. Waste incineration plants in northern China face the problem of low calorific value of waste, especially in winter. Rainy and snowy weather lowers the internal temperature of the waste storage area, and the presence of rain and snow mixed with the waste further affects the quality of waste fermentation, increasing the cost of waste incineration. Therefore, how to increase the temperature inside the waste storage area, thereby improving the quality of waste fermentation, has become a problem that needs to be solved. Utility Model Content

[0003] This utility model addresses the existing technical problems by providing a waste incineration flue gas waste heat recovery and reuse system.

[0004] The technical solution of this utility model to solve the above-mentioned technical problems is as follows: A waste incineration flue gas waste heat recovery and reuse system includes a waste bin, a primary blower, a waste incinerator, a flue gas purification mechanism, an induced draft fan and a chimney arranged in sequence. A waste heat utilization heat exchanger is installed between the waste bin and the primary blower. A three-way ventilation duct is installed between the waste heat utilization heat exchanger and the primary blower. A return centrifugal fan is installed through the three-way ventilation duct. The outlet pipe of the return centrifugal fan is connected to the waste bin.

[0005] Based on the above technical solution, the present invention can be further improved as follows: Preferably, a steam preheater is installed between the primary blower and the flue gas purification mechanism.

[0006] Preferably, a flue gas waste heat recovery heat exchanger is installed between the induced draft fan and the chimney. The inlet of the flue gas waste heat recovery heat exchanger is connected to a cooling water tank via a pipeline, the outlet of the flue gas waste heat recovery heat exchanger is connected to the inlet of the waste heat utilization heat exchanger, and the outlet of the waste heat utilization heat exchanger is connected to the cooling water tank via a pipeline.

[0007] Preferably, the cooling water tank is connected to the flue gas waste heat recovery heat exchanger via a circulating water pipe, and the circulating water pipe is equipped with a circulating water pump set, valves and check valves.

[0008] The flue gas purification mechanism includes a semi-dry desulfurization tower, an activated carbon adsorption device, and a bag filter connected in sequence.

[0009] The beneficial effects of this utility model are: by installing a return centrifugal fan between the waste heat utilization heat exchanger and the primary blower, part of the waste gas after heat exchange is transported to the garbage bin, thereby increasing the temperature inside the garbage bin, ensuring the quality of garbage fermentation in the northern winter, reducing energy consumption, shortening the stacking and turnover time, increasing the calorific value of the garbage, and saving operating costs. At the same time, the temperature of the primary air is increased through the waste heat utilization heat exchanger. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the waste incineration flue gas waste heat recovery and reuse system of this utility model.

[0011] The attached diagram is labeled as follows: 1. Flue gas waste heat recovery heat exchanger; 2. Cooling water tank; 3. Circulating water pump set; 4. Valve; 5. Check valve; 6. Circulating water pipeline; 7. Waste heat utilization heat exchanger; 8. Return centrifugal fan; 9. Exhaust gas duct; 10. Garbage bin; 11. Primary blower; 12. Waste incinerator; 13. Semi-dry desulfurization tower; 14. Activated carbon adsorption device; 15. Bag filter; 16. Exhaust fan; 17. Flue gas duct; 18. Chimney; 19. Steam preheater. Detailed Implementation

[0012] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0013] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. The terms "vertical," "upper," "lower," "horizontal," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on this utility model.

[0014] like Figure 1As shown, this utility model discloses a waste incineration flue gas waste heat recovery and reuse system, including a waste bin 10, a primary blower 11, a waste incinerator 12, a flue gas purification mechanism, an induced draft fan 16, and a chimney 18 arranged in sequence. The flue gas purification mechanism includes a semi-dry desulfurization tower 13, an activated carbon adsorption device 14, and a bag filter 15 connected in sequence. A waste heat utilization heat exchanger 7 is installed on the exhaust gas duct 9 between the waste bin 10 and the primary blower 11. A three-way ventilation duct is installed between the waste heat utilization heat exchanger 7 and the primary blower 11. A return centrifugal fan 8 is installed through the three-way ventilation duct. The outlet pipe of the return centrifugal fan 8 is connected to the waste bin 10. In winter, the return centrifugal fan 8 can be turned on to transport some of the heat-exchanged exhaust gas into the waste bin 10. The heat-exchanged air returns to the waste bin 10, increasing the temperature inside the waste bin 10, ensuring the quality of waste fermentation in northern winters, shortening the stacking and turnover time, increasing the calorific value of the waste, and simultaneously increasing the temperature of the primary air. The primary air refers to the combustion air supplied from the bottom of the grate into the waste incinerator 12.

[0015] A steam preheater 19 is installed between the primary blower 11 and the flue gas purification mechanism. The garbage in the garbage bin 10 is fed into the garbage incinerator 12 for incineration through the feeding device. The primary blower 11 draws the exhaust gas from the garbage bin 10 and sends it to the steam preheater 19 for heating before it enters the grate of the garbage incinerator 12 for air supply and combustion assistance, which increases the primary air temperature and helps the garbage burn in the furnace of the garbage incinerator 12. The high-temperature flue gas generated by incineration is cooled down by the waste heat boiler tube bundle of the garbage incinerator 12, and the flue gas temperature drops to about 200°C. Then the flue gas passes through the semi-dry desulfurization tower 13 for desulfurization, the activated carbon adsorption device 14 for adsorption of heavy metals, and the bag filter 15 for dust removal. After that, it is sent to the exhaust duct 17 by the induced draft fan 16 and then sent into the chimney 18 for discharge, meeting the emission standards. At this time, the temperature of the flue gas is generally about 140°C and contains a large amount of water vapor.

[0016] A flue gas waste heat recovery heat exchanger 1 is installed between the induced draft fan 16 and the chimney 18. The inlet of the flue gas waste heat recovery heat exchanger 1 is connected to the cooling water tank 2 via a pipeline, and the outlet of the flue gas waste heat recovery heat exchanger 1 is connected to the inlet of the waste heat utilization heat exchanger 7. The outlet of the waste heat utilization heat exchanger 7 is also connected to the cooling water tank 2 via a pipeline. The cooling water tank 2 is connected to the flue gas waste heat recovery heat exchanger 1 via a circulating water pipeline 6. A circulating water pump set 3, a valve 4, and a check valve 5 are installed on the circulating water pipeline 6. The main function of the valve 4 is to control the flow of water in the circulating water pipeline 6, so that the water flow can be easily opened or closed when needed. The function of the check valve 5 is to prevent backflow of water. When the circulating water pump set 3 stops working, the check valve 5 can automatically close, preventing the water in the flue gas waste heat recovery heat exchanger 1 from flowing back into the cooling water tank 2, thereby ensuring the normal operation of the system and the safety of the equipment.

[0017] Among them, the flue gas waste heat recovery heat exchanger 1 and the waste heat utilization heat exchanger 7 are both tubular heat exchangers. The heat exchange medium flowing in the tube side of the tubular heat exchanger is circulating water; the heat exchange medium flowing in the shell side is flue gas or air. The heat exchange medium in the shell side of the flue gas waste heat recovery heat exchanger 1 is the flue gas treated by the waste incinerator 12 through the flue gas purification mechanism. The heat exchange medium in the shell side of the waste heat utilization heat exchanger 7 is the waste gas drawn from the waste bin 10 by the primary blower 11.

[0018] During operation, water in the cooling water tank 2 flows into the flue gas waste heat recovery heat exchanger 1 through the circulating water pipe 6, absorbing some heat and simultaneously cooling the flue gas. This process further whitens and removes water vapor, dust, and sulfur dioxide contained within the water vapor. Wastewater generated from flue gas condensation is transported to the sewage treatment plant via pipeline. This effectively further purifies the flue gas physically, reducing the emission of water vapor heat, dust, and sulfur dioxide into the atmosphere. After absorbing heat in the flue gas waste heat recovery heat exchanger 1, the water, under the action of the circulating water pump set 3, enters the waste heat utilization heat exchanger 7, where it exchanges heat with the exhaust gas extracted from the garbage bin 10 by the primary blower 11. This releases the heat from the water, increasing the exhaust gas temperature. The high-temperature exhaust gas, transported by the primary blower 11, enters the grate of the garbage incinerator 12 for combustion support, increasing the primary air temperature and aiding in the combustion of garbage within the furnace of the garbage incinerator 12. Simultaneously, this reduces the steam consumption of the steam preheater 19, lowering operating costs.

[0019] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A waste incineration flue gas waste heat recovery and reuse system, characterized in that, The system includes a waste bin (10), a primary blower (11), a waste incinerator (12), a flue gas purification mechanism, an induced draft fan (16), and a chimney (18) arranged in sequence. A waste heat utilization heat exchanger (7) is installed between the waste bin (10) and the primary blower (11). A three-way ventilation duct is installed between the waste heat utilization heat exchanger (7) and the primary blower (11). A return centrifugal fan (8) is installed through the three-way ventilation duct. The outlet pipe of the return centrifugal fan (8) is connected to the waste bin (10).

2. The waste incineration flue gas waste heat recovery and recycling system according to claim 1, characterized in that, A steam preheater (19) is installed between the primary blower (11) and the flue gas purification mechanism.

3. The waste incineration flue gas waste heat recovery and recycling system according to claim 1 or 2, characterized in that, A flue gas waste heat recovery heat exchanger (1) is installed between the induced draft fan (16) and the chimney (18). The inlet of the flue gas waste heat recovery heat exchanger (1) is connected to the cooling water tank (2) through a pipeline. The outlet of the flue gas waste heat recovery heat exchanger (1) is connected to the inlet of the waste heat utilization heat exchanger (7). The outlet of the waste heat utilization heat exchanger (7) is connected to the cooling water tank (2) through a pipeline.

4. The waste incineration flue gas waste heat recovery and recycling system according to claim 3, characterized in that, The cooling water tank (2) is connected to the flue gas waste heat recovery heat exchanger (1) through the circulating water pipe (6). The circulating water pipe (6) is equipped with a circulating water pump set (3), a valve (4) and a check valve (5).

5. The waste incineration flue gas waste heat recovery and recycling system according to claim 1, characterized in that, The flue gas purification mechanism includes a semi-dry desulfurization tower (13), an activated carbon adsorption device (14), and a bag filter (15) connected in sequence.

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