A flue gas waste heat recovery device

Abstract

This utility model discloses a flue gas waste heat recovery device, relating to the field of heat recovery technology, aiming to solve the problem of low recovery efficiency and waste in existing heat recovery devices. This boiler flue gas heat recovery device guides flue gas flow through a flue pipe, sequentially passing through a gas-liquid heat recovery component and a gas-to-gas heat recovery component to achieve staged recovery of flue gas waste heat. The flue pipe includes a connecting pipe and a heat recovery pipe. The connecting pipe is located at both ends of the heat recovery pipe, connecting it to the boiler flue gas outlet and the blower. The gas-liquid heat recovery component is arranged on the upper part of the heat recovery pipe, near the boiler flue gas outlet, and can preferentially exchange heat with high-temperature flue gas. The gas-to-gas heat recovery component is located behind the gas-liquid heat recovery component, also installed on the upper part of the heat recovery pipe. It mainly reduces the flue gas emission temperature through heat exchange between flue gas and fresh air or low-temperature flue gas, maximizing waste heat recovery and improving overall energy efficiency.

Description

Technical Field

[0001] This utility model relates to the field of heat recovery technology, and in particular to a flue gas waste heat recovery device. Background Technology

[0002] A boiler is an energy conversion device. The energy input to a boiler includes the chemical energy of fuel and electrical energy. The boiler outputs steam, high-temperature water, or organic heat carriers with a certain amount of thermal energy. The original meaning of "boiler" refers to a water-filled container heated over a fire, while "furnace" refers to the place where fuel is burned. A boiler consists of both the boiler and the furnace. The hot water or steam produced in a boiler can directly provide the heat energy needed for industrial production and daily life. Boilers that provide hot water are called hot water boilers, mainly used for domestic purposes, with some applications in industrial production.

[0003] Currently, most boiler flue gas is directly treated as waste gas and then discharged into the air, without recovering or utilizing the heat in the flue gas. Combined with the continuous heat dissipation from the boiler itself, this results in significant energy waste, high energy consumption, and high operating costs. Therefore, boiler flue gas heat recovery devices have emerged to address this need.

[0004] Existing heat recovery devices are generally divided into three types: gas-gas, gas-liquid, and gas-steam. Current technologies typically use only a single recovery method, and the flue gas still retains residual heat after recovery, resulting in incomplete recovery and waste. Utility Model Content

[0005] To address the above shortcomings, this utility model provides a flue gas waste heat recovery device that can solve the technical problems mentioned in the background.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A flue gas waste heat recovery device includes a flue pipe, a gas-liquid heat recovery component, and a gas-gas heat recovery component. The flue pipe includes a connecting pipe and a heat recovery pipe. The connecting pipe is located at both ends of the heat recovery pipe and communicates with the heat recovery pipe for connection to the boiler flue outlet and a blower. The gas-liquid heat recovery component is located on the upper part of the heat recovery pipe and close to the boiler flue outlet. The gas-gas heat recovery component is installed on the upper part of the heat recovery pipe and located behind the gas-liquid heat recovery component.

[0008] Preferably, it also includes heat-conducting columns, which are multiple and distributed in a matrix on the upper part of the flue pipe. The lower part of the multiple heat-conducting columns extends into the heat recovery pipe, and the upper part extends into the gas-liquid heat recovery component and the gas-gas heat recovery component.

[0009] Preferably, the connecting pipe is equipped with a flange, and the connecting pipe is connected to the boiler flue gas outlet and the blower through the flange.

[0010] Preferably, it also includes a filter, which is installed at the end of the connecting pipe connected to the boiler flue gas outlet to filter out particulate matter in the flue gas.

[0011] Preferably, the gas-liquid heat recovery component includes a water heating box, which is sealed and installed on the upper part of the heat recovery pipe. The water heating box is provided with an inlet and an outlet. The inlet is located on the lower part of the side of the water heating box near the end of the gas-liquid heat recovery component, and the outlet is located on the upper part of the water heating box near the end of the boiler flue gas outlet.

[0012] Preferably, the gas-to-gas heat recovery component includes a gas heating box, which is sealed and installed on the upper part of the heat recovery pipe and located at the rear of the gas-liquid heat recovery component. The gas heating box is provided with an air inlet and an air outlet. The air inlet is located on the lower part of the side of the gas heating box away from the gas-liquid heat recovery component, and the air outlet is located on the upper part of the gas heating box near the gas-liquid heat recovery component.

[0013] Preferably, it also includes an insulation shell and a support. The insulation shell is installed outside the flue pipe, the gas-liquid heat recovery component and the gas-gas heat recovery component, and the support is installed at the bottom of the insulation shell to support the entire device.

[0014] Preferably, the water heating tank is also equipped with a drain outlet, which is located on the lower part of the side of the water heating tank near the water outlet.

[0015] Preferably, the gas heating box is also equipped with a temperature and pressure gauge, which is located on the top of the gas heating box.

[0016] Preferably, the heat-conducting pillar also includes heat-conducting plates, and there are multiple heat-conducting plates that are evenly distributed longitudinally on the heat-conducting pillar.

[0017] Compared with existing technologies, the beneficial effects of this utility model are as follows: This boiler flue gas heat recovery device guides the flow of flue gas through a flue pipe, and the gas passes through a gas-liquid heat recovery component and a gas-to-gas heat recovery component in sequence, achieving staged recovery of waste heat from the flue gas. The flue pipe includes a connecting pipe and a heat recovery pipe. The connecting pipe is located at both ends of the heat recovery pipe, connecting it to the boiler flue gas outlet and the blower. The gas-liquid heat recovery component is arranged on the upper part of the heat recovery pipe, close to the boiler flue gas outlet, and can preferentially exchange heat with the high-temperature flue gas. The gas-to-gas heat recovery component is located behind the gas-liquid heat recovery component, also installed on the upper part of the heat recovery pipe. It mainly reduces the flue gas emission temperature through heat exchange between the flue gas and fresh air or low-temperature flue gas, so that the waste heat can be recovered to the maximum extent. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings used in the description of the embodiments will be briefly introduced below.

[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 cross-sectional view of the present invention;

[0022] Figure 4 This is a schematic diagram of the overall structure of the heat-conducting column in this utility model.

[0023] 1. Flue pipe; 101. Connecting pipe; 102. Heat recovery pipe; 103. Flange; 2. Gas-liquid heat recovery component; 201. Water heating box; 202. Water outlet; 203. Sewage outlet; 204. Water inlet; 3. Gas-gas heat recovery component; 301. Gas heating box; 302. Gas outlet; 303. Temperature and pressure gauge; 304. Gas inlet; 4. Bracket; 5. Insulation shell; 6. Filter; 7. Heat-conducting column; 701. Heat-conducting plate. 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. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the scope of protection of the present utility model.

[0025] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are 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, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0026] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances. Furthermore, the technical features involved in the different embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.

[0027] This utility model provides a flue gas waste heat recovery device, aiming to solve the problem of low recovery efficiency and waste inherent in existing heat recovery devices. Figures 1-4 As shown, the boiler flue gas heat recovery device guides the flow of flue gas through the flue pipe 1, and the gas passes sequentially through the gas-liquid heat recovery component 2 and the gas-gas heat recovery component 3 to achieve staged recovery of waste heat from the flue gas. The flue pipe 1 includes a connecting pipe 101 and a heat recovery pipe 102. The connecting pipe 101 is located at both ends of the heat recovery pipe 102, connecting it to the boiler flue gas outlet and the blower to ensure that the flue gas can flow smoothly to the recovery device. The heat recovery pipe 102 serves as the main channel through which the flue gas flows, carrying the heat exchange components and providing sufficient heat exchange space. The gas-liquid heat recovery component 2 is arranged on the upper part of the heat recovery pipe 102, close to the boiler flue gas outlet. It can preferentially exchange heat with the high-temperature flue gas, transferring heat to the liquid carrier, thereby improving the thermal energy utilization rate and reducing the temperature of the flue gas entering the subsequent heat exchange unit, thus reducing the burden on the subsequent heat exchangers. The gas-to-gas heat recovery component 3 is located behind the gas-liquid heat recovery component 2 and is also installed on the upper part of the heat recovery pipe 102. It mainly reduces the flue gas emission temperature by exchanging heat between flue gas and fresh air or low-temperature flue gas, so that waste heat can be recovered to the maximum extent and the overall energy efficiency can be improved. The two-stage heat exchange method allows the heat of flue gas to be recovered in stages, avoiding the problem of incomplete heat exchange caused by a single heat exchange method, improving energy utilization, reducing boiler operating costs, and reducing waste heat emissions from flue gas, thus reducing environmental thermal pollution.

[0028] In a preferred embodiment, the system further includes heat-conducting columns 7, which are arranged in a matrix on the upper part of the flue duct 1. This effectively increases the heat exchange area and improves heat transfer efficiency. The lower part of the columns extends into the heat recovery pipe 102, directly contacting the high-temperature flue gas, rapidly absorbing heat from the flue gas, and transferring the heat along the heat-conducting columns 7 to the upper part. The upper part extends into the gas-liquid heat recovery component 2 and the gas-to-gas heat recovery component 3, respectively, enabling efficient heat transfer to the liquid carrier or fresh air, achieving more complete heat energy recovery. Through the conduction effect of the heat-conducting columns 7, not only is the overall heat transfer capacity of the heat exchange device improved, but the heat distribution is also balanced, avoiding local overheating or uneven heat exchange, thus improving the system's stability and energy efficiency.

[0029] In a preferred embodiment, the heat-conducting column 7 further includes heat-conducting plates 701, which are uniformly distributed along the longitudinal direction of the heat-conducting column 7, significantly increasing the heat exchange area of ​​the heat-conducting column 7 and thereby improving heat transfer efficiency. The heat-conducting plates 701 can more quickly absorb the heat obtained from the flue gas by the heat-conducting column 7 and evenly diffuse it to the gas-liquid heat recovery component 2 and the gas-gas heat recovery component 3, making more efficient use of thermal energy. Simultaneously, the arrangement of the heat-conducting plates 701 optimizes the flue gas flow path, reduces the flow resistance of the flue gas within the heat recovery pipe 102, ensures that the flue gas can fully contact the heat exchange components, and improves the overall heat exchange efficiency.

[0030] In a preferred embodiment, the connecting pipe 101 is provided with a flange 103, and the connecting pipe 101 is connected to the boiler flue gas outlet and the blower through the flange 103. The flange 103 enhances the sealing between the connecting pipe 101 and the boiler flue gas outlet and the blower, ensuring that the flue gas will not leak during transportation, thereby improving the safety and stability of the system. The flange 103 connection method facilitates installation and disassembly, making equipment maintenance and repair convenient and reducing operating and maintenance costs. At the same time, the flange 103 connection has strong high temperature and pressure resistance, which can adapt to the working environment of boiler flue gas and ensure long-term stable operation. In addition, the flange 103 can effectively reduce stress concentration at the connection point, avoid interface deformation or damage caused by thermal expansion and contraction, and improve the durability and overall service life of the equipment.

[0031] In a preferred embodiment, a filter 6 is also included. The filter 6 is installed at the end of the connecting pipe 101 connected to the boiler flue gas outlet to filter particulate matter in the flue gas. The filter 6, installed at the end of the connecting pipe 101 connected to the boiler flue gas outlet, effectively filters particulate matter in the flue gas, reducing the amount of particulate matter entering the heat recovery device and preventing heat exchange components from being affected by ash accumulation, thus improving heat exchange efficiency. The filter 6 not only improves the cleanliness of the flue gas but also reduces the risk of internal contamination and blockage, decreases the frequency of cleaning and maintenance, and extends the service life of the equipment.

[0032] In a preferred embodiment, the gas-liquid heat recovery component 2 includes a water heating tank 201, which is sealed and installed on the upper part of the heat recovery pipe 102. This allows for full utilization of waste heat from the flue gas to heat the water, achieving efficient gas-liquid heat exchange. The water inlet 204 is located on the lower side near one end of the gas-liquid heat recovery component 3, allowing cold water to enter from a lower temperature region and gradually receive heat, reducing temperature fluctuations and improving heat exchange uniformity. The water outlet 202 is located on the upper part near the boiler flue gas outlet, allowing the heated water to flow out from the top, ensuring stable thermal convection inside the water heating tank 201 and improving heat transfer efficiency. The drain outlet 203 is located on the lower side near the outlet 202, allowing for timely removal of deposited impurities and scale from the water, preventing scale accumulation from affecting heat exchange performance, facilitating equipment maintenance, and extending service life. The layout of the water heating box 201 optimizes the water flow path, ensuring that the water temperature gradually increases, improving heat recovery efficiency, while reducing the flue gas temperature, creating more suitable operating conditions for the subsequent gas-to-gas heat recovery component 3, and achieving more complete utilization of waste heat.

[0033] In a preferred embodiment, the gas-to-gas heat recovery component 3 includes a gas heating box 301, which is sealed and installed on the upper part of the heat recovery pipe 102 and located at the rear of the gas-liquid heat recovery component 2. It further recovers the waste heat of the flue gas through heat exchange between the flue gas and air. The gas heating box 301 is provided with an inlet 304 and an outlet 302. The inlet 304 is located on the lower side of the gas heating box 301 at the end away from the gas-liquid heat recovery component 2, allowing low-temperature air to enter from the bottom and gradually increase in temperature after heat exchange with the flue gas. The outlet 302 is located on the upper part near the end of the gas-liquid heat recovery component 2, allowing the heated air to exit from the top, ensuring smooth airflow within the box and effectively improving heat exchange efficiency. The arrangement of the gas heating box 301 ensures that the gas can fully contact the flue gas flow, maximizing the recovery and utilization of heat energy during the gas-to-gas heat exchange process. To monitor the operating status of the gas heating chamber 301, a temperature and pressure gauge 303 is also installed on the top of the chamber. This gauge monitors the temperature and pressure of the gas inside in real time, ensuring the stability and safety of the gas heating process. The data displayed by the temperature and pressure gauge 303 helps operators understand the operating status of the heating chamber and make necessary adjustments to avoid affecting the heat recovery effect due to excessively high or low temperatures, thus optimizing equipment operating efficiency and safety.

[0034] In a preferred embodiment, the system further includes an insulation shell 5 and a support 4. The insulation shell 5 covers the outside of the flue gas duct 1, the gas-liquid heat recovery component 2, and the gas-to-gas heat recovery component 3, providing effective heat insulation. The insulation shell 5 reduces heat loss from the equipment surface, minimizes the impact of ambient temperature on the heat recovery process, and ensures that the flue gas maintains a high temperature during heat exchange, thereby improving heat recovery efficiency. Simultaneously, the insulation shell 5 prevents operators from contacting the high-temperature surface, ensuring operational safety and reducing energy waste. The support 4 is installed at the lower part of the insulation shell 5 to support the entire device, ensuring the stability and fixed position of each component and preventing the equipment from shifting or being damaged due to vibration or external forces.

[0035] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

Claims

1. A flue gas heat recovery device comprising a flue gas duct (1), characterised in that: It also includes a gas-liquid heat recovery component (2) and a gas-gas heat recovery component (3). The flue pipe (1) includes a connecting pipe (101) and a heat recovery pipe (102). The connecting pipe (101) is located at both ends of the heat recovery pipe (102) and communicates with the heat recovery pipe (102) to connect to the boiler flue outlet and the blower. The gas-liquid heat recovery component (2) is located on the upper part of the heat recovery pipe (102) and close to the boiler flue outlet. The gas-gas heat recovery component (3) is installed on the upper part of the heat recovery pipe (102) and located at the rear of the gas-liquid heat recovery component (2).

2. A flue gas heat recovery device according to claim 1, characterised in that: It also includes heat-conducting columns (7), which are multiple and distributed in a matrix on the upper part of the flue pipe (1). The lower part of the multiple heat-conducting columns (7) extends into the heat recovery pipe (102), and the upper part extends into the gas-liquid heat recovery component (2) and the gas-gas heat recovery component (3).

3. A flue gas heat recovery device according to claim 1, characterised in that: The connecting pipe (101) is provided with a flange (103), and the connecting pipe (101) is connected to the boiler flue gas outlet and the blower through the flange (103).

4. A flue gas heat recovery device according to claim 1, characterised in that: It also includes a filter (6), which is installed at the end of the connecting pipe (101) connected to the boiler flue gas outlet to filter out part of the flue gas.

5. A flue gas heat recovery device according to claim 1, characterised in that: The gas-liquid heat recovery component (2) includes a water heating tank (201), which is sealed and installed on the upper part of the heat recovery pipe (102). The water heating tank (201) is provided with an inlet (204) and an outlet (202). The inlet (204) is located on the lower part of the side of the water heating tank (201) near the end of the gas-liquid heat recovery component (3), and the outlet (202) is located on the upper part of the water heating tank (201) near the end of the boiler flue gas outlet.

6. A flue gas heat recovery device according to claim 1, characterised in that: The gas-to-gas heat recovery component (3) includes a gas heating box (301), which is sealed and installed on the upper part of the heat recovery pipe (102) and located at the rear of the gas-liquid heat recovery component (2). The gas heating box (301) is provided with an air inlet (304) and an air outlet (302). The air inlet (304) is located on the lower part of the side of the gas heating box (301) away from the gas-liquid heat recovery component (2), and the air outlet (302) is located on the upper part of the gas heating box (301) near the gas-liquid heat recovery component (2).

7. The flue gas waste heat recovery device according to claim 1, characterized in that: It also includes an insulation shell (5) and a bracket (4). The insulation shell (5) covers the outside of the flue pipe (1), the gas-liquid heat recovery component (2) and the gas-gas heat recovery component (3). The bracket (4) is installed on the lower part of the insulation shell (5) to support the entire device.

8. The flue gas waste heat recovery device according to claim 5, characterized in that: The water heating tank (201) is also provided with a drain outlet (203), which is located on the lower part of the side of the water heating tank (201) near the water outlet (202).

9. A flue gas waste heat recovery device according to claim 6, characterized in that: The gas heating box (301) is also equipped with a temperature and pressure gauge (303), which is located on the top of the gas heating box (301).

10. A flue gas waste heat recovery device according to claim 2, characterized in that: The heat-conducting column (7) also includes heat-conducting plates (701), and there are multiple heat-conducting plates (701) that are evenly distributed longitudinally on the heat-conducting column (7).

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