Waste incineration slag waste heat recovery system

Abstract

The utility model belongs to the technical field of waste incineration waste heat recovery, and relates to a waste incineration slag waste heat recovery system which comprises a waste incinerator, a slag heat exchange bin and an air heat exchanger which are sequentially connected, and a heat exchange coil of the slag heat exchange bin is filled with a heat exchange working medium and is provided with a heat exchange working medium outlet and a recycling opening; a heat exchange working medium inlet, a heat exchange working medium outlet, an air inlet and an air outlet are formed in the air heat exchanger, and the air outlet is connected to a primary air system of the garbage incinerator; the air heat exchanger working medium inlet is connected with the slag heat exchange bin working medium outlet through a pipeline; the air heat exchanger working medium outlet is connected with the slag heat exchange bin working medium recycling port through a pipeline; a working medium is heated by slag in the slag heat exchange bin, then enters the air heat exchanger to exchange heat with cold air and then flows back to the slag heat exchange bin, and hot air heated by the working medium enters a primary air system of the garbage incinerator. The furnace slag heat is recycled into the incinerator, the furnace slag heat is effectively recycled, and the heat energy utilization rate of a waste incineration plant is increased.

Description

Technical Field

[0001] The utility model belongs to the technical field of waste incineration waste heat recovery and relates to a waste incineration slag waste heat recovery system. Background Art

[0002] Incineration of domestic waste is a waste disposal method encouraged and strongly advocated by the country. Because grate-type incinerators have the advantages of mature technology, stable operation, reliability, and wide adaptability, their application accounts for more than 80% of the total global waste incineration market. At present, incineration plants generally use slag pickers to transfer the slag after the combustion of domestic waste, and push it to the slag pit, and then realize resource utilization through transportation and treatment. The slag outlet temperature of the waste incinerator is about 300℃, and the slag discharged through the slag outlet has a certain sensible heat. The liquid-sealed slag picker mixes water and slag and sends them into the slag pit together, using a large amount of cooling water to cool the high-temperature slag. This practice not only wastes water resources, but also makes it difficult to fully recycle the heat of the slag. Utility Model Content

[0003] In view of this, the purpose of the utility model is to provide a waste incineration slag waste heat recovery system, which can effectively recycle the heat of the slag and improve the thermal energy utilization rate of the waste incineration plant.

[0004] In order to achieve the above-mentioned purpose, the utility model provides a waste incineration slag waste heat recovery system, comprising a waste incinerator, a slag heat exchange bin and an air heat exchanger connected in sequence; a heat exchange coil is arranged in the slag heat exchange bin, and a heat exchange medium is filled in the heat exchange coil; the heat exchange coil has a heat exchange medium outlet and a heat exchange medium recycling port; the air heat exchanger is provided with a heat exchange medium inlet and a heat exchange medium discharge port as well as an air inlet and an air outlet, the air outlet is connected to the primary air system of the waste incinerator, and the heat exchange medium inlet and the heat exchange medium discharge port as well as the air inlet and the air outlet are all equipped with thermocouples.

[0005] The heat exchange medium inlet of the air heat exchanger and the heat exchange medium outlet of the slag heat exchange bin are connected by a pipeline, and the heat exchange medium discharge port of the air heat exchanger and the heat exchange medium recycling port of the slag heat exchange bin are connected by a pipeline. After the heat exchange medium is heated by the slag in the slag heat exchange bin, it enters the air heat exchanger to exchange heat with the cold air, and then flows back to the slag heat exchange bin. The hot air heated by the heat exchange medium enters the primary air system and flows into the waste incinerator.

[0006] Optionally, a drum screen is also provided between the waste incinerator and the slag heat exchange bin. The slag discharge port of the waste incinerator is connected to the drum screen. After the slag is screened by the drum screen, the large-particle slag is discharged to the slag pit through the coarse material outlet of the drum screen, and the small-particle slag is discharged to the slag heat exchange bin through the fine material outlet of the drum screen.

[0007] Optionally, the waste incinerator is a grate-type incinerator, and the air supply duct of the primary air system is connected to the lower part of the grate.

[0008] Optionally, the waste incinerator has a slag discharge port at the bottom and a high-temperature flue gas outlet at the top.

[0009] Optionally, the small-size slag is outside the heat exchange coil and exchanges heat with the heat exchange medium inside the heat exchange coil in a non-contact manner.

[0010] Optionally, a star-shaped discharge valve is provided at the lower part of the slag heat exchange bin, and the low-temperature slag after heat exchange is discharged into the slag pit through the star-shaped discharge valve.

[0011] Optionally, the air heat exchanger is a separate heat pipe heat exchanger.

[0012] Optionally, the air outlet of the air heat exchanger is connected to an induced draft fan, and the heated air is transported to the primary air system through the induced draft fan.

[0013] Optionally, the slag pit has a fine material area and a coarse material area, and both the fine material area and the coarse material area are provided with a water curtain system; the coarse material area uses water cooling to cool the slag, and the cooled slag enters a magnetic separation system to recover metal in the slag.

[0014] Optionally, outer surfaces of the drum screen, the slag heat exchange bin and the air heat exchanger are all provided with a heat insulation structure.

[0015] The beneficial effects of the utility model are:

[0016] The waste heat recovery system provided by the utility model recycles the heat of the slag into the incinerator through air circulation, which can effectively recover the heat of the slag, reduce the heat loss of the incineration plant, and improve the thermal energy utilization rate of the waste incineration plant. In addition, the utility model uses the slag heat exchange bin as the intermediate heat exchange medium to avoid direct contact between the slag and the cold air, which can effectively reduce the content of particulate matter in the air and avoid blockage of the primary air system pipeline of the incinerator.

[0017] In addition, the utility model also introduces a drum screen between the incinerator and the slag heat exchange bin to facilitate the subsequent resource utilization of the slag. Specifically, the drum screen performs preliminary screening of coarse and fine materials during the slag collection process to prevent large-diameter slag from falling directly into the slag heat exchange bin and causing wear and damage to the slag heat exchange bin. At the same time, small-diameter slag entering the slag heat exchange bin can effectively increase the filling degree of the heat exchange bin, thereby improving the heat exchange efficiency. There is no large-diameter slag in the heat exchange bin, and the residence time of the slag in the slag heat exchange bin can be controlled by adjusting the rate of the star-shaped discharge valve, thereby ensuring the stable operation of the heat exchange system.

[0018] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and will be apparent to those skilled in the art based on the following examination and research, or can be taught from the practice of the present invention to some extent. The objectives and other advantages of the present invention can be achieved and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model will be described in detail below in conjunction with the accompanying drawings, in which:

[0020] Figure 1 This is a structural schematic diagram of the waste incineration slag waste heat recovery system provided by the utility model.

[0021] Reference numerals:

[0022] 1-waste incinerator; 2-drum screen; 2.1-coarse material outlet; 2.2-fine material outlet; 3-slag heat exchange bin; 3.1-heat exchange medium outlet; 3.2-heat exchange medium recycling outlet; 3.3-star discharge valve; 3.4-heat exchange coil; 4-slag pit; 5-air heat exchanger; 5.1-heat exchange medium inlet; 5.2-heat exchange medium outlet; 5.3-air inlet; 5.4-air outlet; 5.5-safety valve; 6-induced draft fan. DETAILED DESCRIPTION

[0023] The following describes the implementation of the present invention through specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific implementations, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner. The following embodiments and the features in the embodiments can be combined with each other without conflict.

[0024] Among them, the drawings are only used for illustrative explanations, and they only represent schematic diagrams rather than actual pictures, and should not be understood as limitations on the present utility model. In order to better illustrate the embodiments of the present utility model, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0025] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "front", "back" and the like indicate directions or positional relationships, they are based on the directions or positional relationships shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as a limitation on the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0026] See also Figure 1 The utility model provides a waste incinerator 1 slag waste heat recovery system, comprising a waste incinerator 1, a drum screen 2, a slag heat exchange bin 3, an air heat exchanger 5, an induced draft fan 6 and related pipelines connected in sequence.

[0027] The garbage incinerator 1 is a grate type incinerator, the air supply pipe of the primary air system is connected to the lower part of the grate, the bottom of the garbage incinerator 1 has a slag discharge port, and the top has a high-temperature flue gas outlet. The primary air heated by the air preheater enters the incinerator from the lower part of the grate, the domestic garbage and air are fully burned in the incinerator, the slag after combustion is discharged from the slag discharge port, and the high-temperature flue gas is discharged from the high flue gas outlet of the incinerator.

[0028] The slag discharge port of the waste incinerator 1 is connected to the drum screen 2, which is driven by the motor to rotate to screen large-size slag and small-size slag. After screening by the drum screen 2, the large-size slag is discharged to the slag pit 4 through the coarse material outlet 2.1 of the drum screen 2, and the small-size slag is discharged to the slag heat exchange bin 3 through the fine material outlet 2.2 of the drum screen 2.

[0029] The slag heat exchange bin 3 is provided with a heat exchange coil 3.4, which is filled with a heat exchange medium. The heat exchange coil 3.4 has a heat exchange medium outlet 3.1 and a heat exchange medium recycling port 3.2. The air heat exchanger 5 is a separate heat pipe heat exchanger, which is provided with a heat exchange medium inlet 5.1 and a heat exchange medium outlet 5.2 as well as an air inlet 5.3 and an air outlet 5.4. The air outlet 5.4 of the air heat exchanger 5 is connected to an induced draft fan 6, and then connected to the primary air system of the waste incinerator 1.

[0030] The heat exchange medium inlet 5.1 is connected to the heat exchange medium outlet 3.1 through a pipeline, and the heat exchange medium recycling port 3.2 is connected to the heat exchange medium discharge port 5.2 through a pipeline. The small-size slag is heated by the slag in the slag heat exchange bin 3 to form a high-temperature gaseous heat exchange medium, and enters the air heat exchanger 5 to exchange heat with the cold air, fully exchanges heat in the air heat exchanger 5, and then becomes a low-temperature liquid heat exchange medium and flows back to the slag heat exchange bin 3. The hot air heated by the heat exchange medium in the air heat exchanger 5 flows into the waste incinerator 1 as the primary air.

[0031] A star-shaped discharge valve 3.3 is provided at the bottom of the slag heat exchange bin 3, and the low-temperature slag after heat exchange is discharged to the slag pit 4 through the star-shaped discharge valve 3.3. The speed of the star-shaped discharge valve 3.3 is adjustable, and the slag discharge rate is adjusted according to the temperature in the slag heat exchange bin 3 to ensure stable operation of the heat exchange system.

[0032] In some possible embodiments, the outer surfaces of the drum screen 2, the slag heat exchange bin 3 and the air heat exchanger 5 are all provided with insulation structures to prevent the heat of the slag from being lost to the environment. The slag pit 4 has a fine material area and a coarse material area, and both the fine material area and the coarse material area are provided with a water curtain system to achieve the dual purposes of dust removal and cooling. Furthermore, the coarse material area uses water cooling to cool the slag, and the cooled slag enters the magnetic separation system to recover the metal in the slag. The slag after heat exchange is discharged from the bottom of the bin through the star-shaped discharge valve 3.3, and the low-temperature slag is sent to the slag pit 4 through a belt conveyor for subsequent resource utilization. The coarse material outlet 2.1 of the drum screen 2, the outlet of the star-shaped discharge valve 3.3 and the low-temperature fine material conveying equipment are all provided with sealing mechanisms to prevent smoke and dust from spreading into the environment.

[0033] In some possible embodiments, the motors of the drum screen 2, the star-shaped discharge valve 3.3 and the induced draft fan 6 are all variable frequency motors, and the material transfer rate can be controlled by adjusting the motor frequency according to the working conditions; the slag heat exchange bin 3 is equipped with a high-level material level meter and a low-level material level meter for monitoring the material level in the slag heat exchange bin; a plurality of thermocouples are installed at different heights in the slag heat exchange bin 3, especially at the heat exchange medium outlet 3.1 and the heat exchange medium recycling port 3.2, for monitoring the temperature distribution in the slag heat exchange bin; a safety valve 5.5 is also provided on the air heat exchanger 5, and thermocouples are installed at the air inlet 5.3 and air outlet 5.4, the heat exchange medium inlet 5.1 and the heat exchange medium discharge port 5.2 of the air heat exchanger 5 for monitoring the temperature of the heat exchange medium and the air.

[0034] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the utility model.

Claims

1. A waste incineration slag waste heat recovery system, characterized by: It comprises a garbage incinerator (1), a slag heat exchange bin (3) and an air heat exchanger (5) which are connected in sequence; The slag heat exchange bin (3) is provided with a heat exchange coil (3.4), and the heat exchange coil (3.4) is filled with a heat exchange medium; the heat exchange coil (3.4) is provided with a heat exchange medium outlet (3.1) and a heat exchange medium recycling port (3.2); The air heat exchanger (5) is provided with a heat exchange medium inlet (5.1) and a heat exchange medium outlet (5.2), as well as an air inlet (5.3) and an air outlet (5.4), and the air outlet (5.4) is connected to the primary air system of the waste incinerator (1); wherein the heat exchange medium inlet (5.1) and the heat exchange medium outlet (5.2), as well as the air inlet (5.3) and the air outlet (5.4) are all equipped with thermocouples; The heat exchange medium inlet (5.1) and the heat exchange medium outlet (3.1) are connected via a pipeline, and the heat exchange medium discharge port (5.2) and the heat exchange medium recycling port (3.2) are connected via a pipeline; After being heated by the slag in the heat exchange coil (3.4), the heat exchange medium enters the air heat exchanger (5) to exchange heat with cold air, and then flows back to the heat exchange coil (3.4). The hot air heated by the heat exchange medium enters the primary air system and flows into the waste incinerator (1).

2. The system according to claim 1, characterized in that: A drum screen (2) is also provided between the waste incinerator (1) and the slag heat exchange bin (3); the slag discharge port of the waste incinerator (1) is connected to the drum screen (2); after the slag is screened by the drum screen (2), the large-size slag is discharged to the slag pit (4) through the coarse material outlet (2.1) of the drum screen (2), and the small-size slag is discharged to the slag heat exchange bin (3) through the fine material outlet (2.2) of the drum screen (2).

3. The system according to claim 1 or 2, characterized in that: The waste incinerator (1) is a grate-type incinerator, and the air supply duct of the primary air system is connected to the lower part of the grate.

4. The system according to claim 1 or 2, characterized in that: The waste incinerator (1) has a slag discharge port at the bottom and a high-temperature smoke outlet at the top.

5. The system according to claim 2, characterized in that: The small-particle slag exchanges heat with the heat exchange medium in the heat exchange coil (3.4) in a non-contact manner outside the heat exchange coil (3.4).

6. The system according to claim 1 or 2, characterized in that: A star-shaped discharge valve (3.3) is provided at the lower part of the slag heat exchange bin (3), and the low-temperature slag after heat exchange is discharged to the slag pit (4) through the star-shaped discharge valve (3.3).

7. The system according to claim 1 or 2, characterized in that: The air heat exchanger (5) is a separate heat pipe heat exchanger.

8. The system according to claim 1 or 2, characterized in that: The air outlet (5.4) of the air heat exchanger (5) is connected to an induced draft fan (6), and the heated air is transported to the primary air system through the induced draft fan (6).

9. The system according to claim 6, characterized in that: The slag pit (4) has a fine material area and a coarse material area, and both the fine material area and the coarse material area are provided with a water curtain system; the coarse material area uses water cooling to cool the slag, and the cooled slag enters the magnetic separation system to recover the metal in the slag.

10. The system according to claim 2, characterized in that: The outer surfaces of the drum screen (2), the slag heat exchange bin (3) and the air heat exchanger (5) are all provided with heat insulation structures.

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