Natural circulation low-pressure boiler adopting suspension structure

Abstract

The utility model relates to the technical field of boilers, in particular to a natural circulation low-pressure boiler adopting a suspension structure, which comprises a boiler body, a burner is arranged at the bottom of the boiler body, an air pocket is fixedly connected to the top of the boiler body, and a heat energy recovery mechanism is arranged above the outer wall of the boiler body. By arranging the heat energy recovery mechanism, when smoke passes through the smoke exhaust pipe and is prepared to be exhausted, the smoke in the smoke exhaust pipe further contains a large amount of heat, the temperature rising section of the steam pipe is arranged at the position, close to one side of the furnace body, of the smoke exhaust pipe, so that steam in the steam pipe can be further heated when passing through the temperature rising section, and the quality of the steam is improved; and the subsequent flue gas passes through the preheating section of the water inlet pipe in the smoke exhaust pipe, and the injected water body is preheated, so that the heat consumed by subsequent gasification is reduced, the waste heat in the flue gas is utilized as much as possible, and the energy consumption is reduced.

Description

Technical Field

[0001] This utility model relates to the field of boiler technology, specifically to a natural circulation low-pressure boiler with a suspended structure. Background Technology

[0002] Natural circulation low-pressure boilers are a common type of industrial boiler. Natural circulation relies on the density difference between water and a steam-water mixture to achieve the circulation of the working fluid, requiring no additional power equipment and resulting in lower operating costs. Low-pressure operation: Typically operating at low pressures, generally below a few MPa, the pressure resistance requirements for the equipment are relatively low, leading to higher safety. Simple structure: Composed of main components such as the steam drum, downcomer, riser (water-cooled wall), and headers, the structure is relatively simple, resulting in lower manufacturing and installation costs. Strong adaptability: It can adapt to different fuels, such as coal, oil, and gas, and can operate stably under different loads. Industrial production: Widely used in chemical, papermaking, food processing, and pharmaceutical industries to provide steam or hot water for production processes. Heating and hot water supply: Used for heating and hot water supply in buildings to meet people's living needs. Small-scale power generation: In some small power plants, natural circulation low-pressure boilers can be used in conjunction with small steam turbines.

[0003] Existing technology, such as publication number CN201028507Y, provides a natural circulation low-velocity differential pressure fluidized bed boiler, including a fluidized bed, furnace body, boiler drum, coal feeder, embedded tubes, furnace water-cooled walls, economizer, header, air distribution device, and fly ash circulation device. Its key feature is the presence of a partition wall between the front and rear walls of the fluidized bed. The air distribution device includes two isolated air chambers located below the fluidized bed. The air chamber below the front and partition walls is connected to a high-pressure blower, while the air chamber below the partition and rear walls is connected to a low-pressure blower. This creates a high-pressure bed and a low-pressure fly ash burnout bed between the front and partition walls, and between the partition and rear walls. Fresh coal undergoes fluidized combustion in the high-pressure bed, while circulating fly ash undergoes fluidized combustion in the low-pressure fly ash burnout bed. This invention improves combustion efficiency and extends the service life of the embedded tubes.

[0004] In this scheme, the secondary utilization of heat from the flue gas through the riser pipe (water-cooled wall) can increase the efficiency of thermal energy utilization. However, in reality, due to the limited contact time between the riser pipe and the flue gas, the flue gas still contains a high amount of heat, and direct discharge will result in a significant waste of heat. Therefore, we propose a natural circulation low-pressure boiler with a suspended structure. Utility Model Content

[0005] The purpose of this utility model is to provide a natural circulation low-pressure boiler with a suspended structure. This natural circulation low-pressure boiler with a suspended structure solves the problem that due to the limited contact time between the riser pipe and the flue gas, the flue gas still contains a high amount of heat, and direct discharge will still result in a large amount of heat being wasted.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] A natural circulation low-pressure boiler with a suspended structure includes a furnace body, a burner is installed at the bottom of the furnace body, a gas tank is fixedly connected to the top of the furnace body, and a heat recovery mechanism is installed above the outer wall of the furnace body.

[0008] The heat recovery mechanism includes a flue pipe, which is fixedly connected to the upper part of the outer wall of the furnace body. A steam pipe is fixedly connected to the top of the gas chamber, and passes through the flue pipe near the furnace body and extends to the bottom of the flue pipe. A water inlet pipe is fixedly connected to the top of the gas chamber, and passes through the flue pipe away from the furnace body and extends to the bottom of the flue pipe.

[0009] Preferably, the section of the steam pipe inside the flue pipe is the heating section, and the section of the water inlet pipe inside the flue pipe is the preheating section, and both the preheating section and the heating section are arranged in a spiral shape.

[0010] Preferably, a steam connector is fixedly connected to one bottom end of the steam pipe for outputting steam, and a water inlet connector is fixedly connected to one bottom end of the water inlet pipe for connecting cold water.

[0011] Preferably, a drain pipe is fixedly connected to the bottom of the gas chamber, and the drain pipe extends into the furnace body at a lower position, with a cold water ring pipe fixedly connected to one end of the bottom of the drain pipe.

[0012] Preferably, the top of the cold water ring pipe is fixedly connected to multiple water supply pipes, and the multiple water supply pipes are arranged in a ring array, with a hot water ring pipe fixedly connected to the top of the multiple water supply pipes.

[0013] Preferably, a gas-water pipe is fixedly connected to one side of the hot water ring pipe, and the gas-water pipe extends into the interior of the gas chamber. A gas-water separation component is fixedly connected to the end of the gas-water pipe inside the gas chamber.

[0014] Preferably, the gas-water separation assembly consists of a cyclone separator, a funnel, and an exhaust port. The cyclone separator is fixedly connected to the gas-water pipe, and the inner wall of the cyclone separator is tangential to the gas-water pipe. The funnel is fixedly connected to the bottom of the cyclone separator, and the exhaust port is fixedly connected to the top of the cyclone separator.

[0015] By employing the above technical solution, this utility model provides a natural circulation low-pressure boiler with a suspended structure. It possesses at least the following beneficial effects:

[0016] I. This utility model incorporates a heat recovery mechanism. When flue gas passes through the exhaust pipe for discharge, it still contains a significant amount of heat. By arranging a heating section of a steam pipe near the furnace body on the exhaust pipe side, the steam in the steam pipe is further heated as it passes through the heating section, thereby improving the quality of the steam. Subsequently, the flue gas also passes through a preheating section of a water inlet pipe in the exhaust pipe, where the injected water is preheated to reduce the heat consumed in subsequent gasification. This maximizes the utilization of residual heat in the flue gas, thereby reducing energy consumption.

[0017] II. Under the influence of gravity, the water in the gas chamber of this utility model flows from the lower water pipe into the cold water ring pipe inside the furnace body and then into the upper water pipe. When the burner is operating, it generates a large amount of heat. At this time, the water in the upper water pipe will rapidly heat up. As the temperature rises, the thermal motion between water molecules intensifies, the intermolecular distance increases, resulting in volume expansion and vaporization. A mixture of gas and water occurs in the upper water pipe. Due to its light weight, the water will rise in the upper water pipe and be injected into the gas chamber through the hot water ring pipe and the gas-water pipe, thus achieving self-circulation of the water. Attached Figure Description

[0018] The accompanying drawings, which are included to provide a further understanding of the present invention, form part of this application:

[0019] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0020] Figure 2 This is a partial cross-sectional view of the present invention;

[0021] Figure 3 This is a diagram illustrating the structure of the steam pipe and water inlet pipe in this utility model.

[0022] Figure 4 This is a structural diagram of the steam-water separation component in this utility model.

[0023] In the diagram: 1. Burner; 2. Furnace body; 3. Gas manifold; 4. Heat recovery mechanism; 41. Exhaust pipe; 42. Steam pipe; 421. Heating section; 422. Steam connector; 43. Water inlet pipe; 431. Preheating section; 432. Water inlet connector; 5. Drain pipe; 6. Cold water loop pipe; 7. Water supply pipe; 8. Hot water loop pipe; 9. Gas-water pipe; 10. Gas-water separation assembly; 101. Cyclone separator; 102. Funnel; 103. Exhaust port. Detailed Implementation

[0024] The technical solutions of the present utility model 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 utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0025] Example 1

[0026] A natural circulation low-pressure boiler with a suspended structure, such as Figure 1 - Figure 3 As shown, the furnace includes a furnace body 2, a burner 1 at the bottom of the furnace body 2, a gas chamber 3 fixedly connected to the top of the furnace body 2, and a heat recovery mechanism 4 located above the outer wall of the furnace body 2. The heat recovery mechanism 4 includes an exhaust pipe 41, which is fixedly connected to the upper part of the outer wall of the furnace body 2. A steam pipe 42 is fixedly connected to the top of the gas chamber 3, passing through the exhaust pipe 41 near the side of the furnace body 2 and extending to the bottom of the exhaust pipe 41. A water inlet pipe 43 is fixedly connected to the top of the gas chamber 3, passing through the exhaust pipe 41 away from the side of the furnace body 2. The steam pipe 42 extends to the bottom of the flue pipe 41. The section of the steam pipe 42 inside the flue pipe 41 is the heating section 421, and the section of the water inlet pipe 43 inside the flue pipe 41 is the preheating section 431. Both the preheating section 431 and the heating section 421 are spirally arranged. The spiral arrangement can increase the contact area with the flue gas to improve the efficiency of heat transfer. A steam connector 422 is fixedly connected to the bottom end of the steam pipe 42 for outputting steam, and a water inlet connector 432 is fixedly connected to the bottom end of the water inlet pipe 43 for connecting cold water.

[0027] In this embodiment, by setting up a heat recovery mechanism 4, when the flue gas passes through the exhaust pipe 41 for discharge, the flue gas in the exhaust pipe 41 still contains a large amount of heat. By arranging a heating section 421 of the steam pipe 42 near the furnace body 2 on the side of the exhaust pipe 41, the steam in the steam pipe 42 will be further heated when it passes through the heating section 421 to improve the quality of the steam. Subsequently, the flue gas will also pass through the preheating section 431 of the water inlet pipe 43 in the exhaust pipe 41, where the injected water will be preheated to reduce the heat consumed in subsequent gasification, so as to make the most of the residual heat in the flue gas and reduce energy consumption.

[0028] Example 2

[0029] like Figure 2As shown, a drain pipe 5 is fixedly connected to the bottom of the gas chamber 3, and the drain pipe 5 extends into the interior of the furnace body 2 at the bottom. A cold water ring pipe 6 is fixedly connected to one end of the bottom of the drain pipe 5. Multiple water inlet pipes 7 are fixedly connected to the top of the cold water ring pipe 6, and the multiple water inlet pipes 7 are arranged in a ring array. A hot water ring pipe 8 is fixedly connected to the top of the multiple water inlet pipes 7. A gas-water pipe 9 is fixedly connected to one side of the hot water ring pipe 8, and the gas-water pipe 9 extends into the interior of the gas chamber 3. A gas-water separator assembly 10 is fixedly connected to one end of the gas-water pipe 9 inside the gas chamber 3.

[0030] In this embodiment, the water in the air chamber 3 flows from the lower water pipe 5 into the cold water ring pipe 6 inside the furnace body 2 under the action of gravity, and then into the upper water pipe 7. When the burner 1 is operating, it will generate a large amount of heat. At this time, the water in the upper water pipe 7 will heat up rapidly. When the temperature rises, the thermal motion between water molecules intensifies, the intermolecular distance increases, resulting in volume expansion and vaporization. A mixture of gas and water appears in the upper water pipe 7. Due to its light weight, the water will rise in the upper water pipe 7 and be injected into the air chamber 3 through the hot water ring pipe 8 and the gas-water pipe 9, thereby realizing the self-circulation of water.

[0031] Example 3

[0032] like Figure 4 As shown, the gas-water separation assembly 10 consists of a cyclone separator 101, a funnel 102, and an exhaust port 103. The cyclone separator 101 is fixedly connected to the gas-water pipe 9, and the inner wall of the cyclone separator 101 is tangentially arranged with the gas-water pipe 9. The funnel 102 is fixedly connected to the bottom of the cyclone separator 101, and the exhaust port 103 is fixedly connected to the top of the cyclone separator 101.

[0033] In this embodiment, when the gas and water mixture in the gas-water pipe 9 enters the gas chamber 3, it will enter first and enter the cyclone separator 101 in a tangential manner. This tangential entry causes the mixed gas and water to rotate within the cyclone separator 101, forming a rotating airflow. During the rotation, both the gas and the water in it are subjected to centrifugal force. Since the density of water is much greater than that of gas, the centrifugal force it experiences is also greater. Therefore, the water is quickly thrown against the inner wall of the cyclone separator 101 and flows out from the funnel 102 under the action of gravity. The gas is discharged from the exhaust port 103 above to improve the quality of the steam.

[0034] In this invention, a natural circulation low-pressure boiler with a suspended structure is used. Under gravity, the water in the steam drum 3 flows from the lower water pipe 5 into the cold water ring pipe 6 inside the furnace body 2, and then into the upper water pipe 7. When the burner 1 operates, it generates a large amount of heat. At this time, the water in the upper water pipe 7 rapidly heats up. As the temperature rises, the thermal motion between water molecules intensifies, the intermolecular distance increases, resulting in volume expansion and vaporization. A mixture of gas and water occurs in the upper water pipe 7. Due to its lighter weight, the water rises within the upper water pipe 7 and is injected into the steam drum 3 via the hot water ring pipe 8 and the gas-water pipe 9, thus achieving self-circulation of the water. When the flue gas passes through the exhaust pipe 41 for discharge, it still contains a large amount of heat. This heat is generated by arranging a heating section 421 of the steam pipe 42 near the furnace body 2 on the side of the exhaust pipe 41. This process ensures that the steam in the steam pipe 42 is further heated when it passes through the heating section 421 to improve the quality of the steam. Subsequently, the flue gas will also pass through the preheating section 431 of the water inlet pipe 43 in the exhaust pipe 41, where the injected water will preheat the gas to reduce the heat consumed in subsequent gasification. When the gas and water mixture in the gas-water pipe 9 enters the gas chamber 3, it will enter first and enter the cyclone separator 101 tangentially. This tangential entry causes the mixed gas and water to rotate within the cyclone separator 101, forming a rotating airflow. During the rotation, both the gas and the water in it are subjected to centrifugal force. Since the density of water is much greater than that of gas, the centrifugal force is also greater. Therefore, the water will be quickly thrown against the inner wall of the cyclone separator 101 and flow out from the funnel 102 under the action of gravity. The gas is discharged from the exhaust port 103 above to improve the quality of the steam.

[0035] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0036] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A natural circulation low-pressure boiler with a suspended structure, comprising a furnace body (2), characterized in that: A burner (1) is provided at the bottom of the furnace body (2), a gas bag (3) is fixedly connected to the top of the furnace body (2), and a heat recovery mechanism (4) is provided above the outer wall of the furnace body (2). The heat recovery mechanism (4) includes a flue pipe (41), which is fixedly connected to the upper part of the outer wall of the furnace body (2). A steam pipe (42) is fixedly connected to the top of the gas chamber (3), and passes through the flue pipe (41) near the side of the furnace body (2) and extends to the bottom of the flue pipe (41). A water inlet pipe (43) is fixedly connected to the top of the gas chamber (3), and passes through the flue pipe (41) away from the side of the furnace body (2) and extends to the bottom of the flue pipe (41).

2. A natural circulation low-pressure boiler with a suspended structure according to claim 1, characterized in that: The section of the steam pipe (42) inside the flue pipe (41) is the heating section (421), and the section of the water inlet pipe (43) inside the flue pipe (41) is the preheating section (431). Both the preheating section (431) and the heating section (421) are arranged in a spiral shape.

3. A natural circulation low-pressure boiler with a suspended structure according to claim 1, characterized in that: The bottom end of the steam pipe (42) is fixedly connected to a steam connector (422) for outputting steam, and the bottom end of the water inlet pipe (43) is fixedly connected to a water inlet connector (432) for connecting to cold water.

4. A natural circulation low-pressure boiler with a suspended structure according to claim 1, characterized in that: The bottom of the air bag (3) is fixedly connected to a drain pipe (5), and the drain pipe (5) extends into the furnace body (2) at the bottom. One end of the drain pipe (5) is fixedly connected to a cold water ring pipe (6).

5. A natural circulation low-pressure boiler with a suspended structure according to claim 4, characterized in that: The top of the cold water ring pipe (6) is fixedly connected to multiple water supply pipes (7), and the multiple water supply pipes (7) are arranged in a ring array. The top of the multiple water supply pipes (7) is fixedly connected to a hot water ring pipe (8).

6. A natural circulation low-pressure boiler with a suspended structure according to claim 5, characterized in that: A gas-water pipe (9) is fixedly connected to one side of the hot water ring pipe (8), and the gas-water pipe (9) extends into the interior of the gas chamber (3). A gas-water separation component (10) is fixedly connected to one end of the gas-water pipe (9) inside the gas chamber (3).

7. A natural circulation low-pressure boiler with a suspended structure according to claim 6, characterized in that: The gas-water separation assembly (10) consists of a cyclone separator (101), a funnel (102), and an exhaust port (103). The cyclone separator (101) is fixedly connected to the gas-water pipe (9), and the inner wall of the cyclone separator (101) is tangentially connected to the gas-water pipe (9). The funnel (102) is fixedly connected to the bottom of the cyclone separator (101), and the exhaust port (103) is fixedly connected to the top of the cyclone separator (101).

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