Condensing gas wall-hung boiler

Abstract

The utility model relates to gas stove technical field discloses a kind of condensing gas wall-hung boiler, comprising: shell;Gas stove table;Combustor;Main heat exchanger is set to the inside of shell and is located at the top of combustor, for using the sensible heat of high-temperature flue gas and heat is transferred to heating circulating water;First condensing heat exchanger is set to the inside of shell and is located at the top of main heat exchanger side, for first stage condensing heat exchange to flue gas, recovers flue gas latent heat to primary preheating heating circulating water;Second condensing heat exchanger is set to the inside of shell and is located at the top of main heat exchanger other side, for second stage condensing heat exchange to flue gas, recovers flue gas latent heat to secondary preheating heating circulating water;Circulating water pump;Controller.The utility model solves the problem that gas wall-hung boiler only sets single-stage heat exchanger and leads to flue gas sensible heat and condensing latent heat utilization is not sufficient, heat efficiency is low, gas consumption is high.

Description

Technical Field

[0001] This utility model relates to the field of gas furnace technology, specifically to a condensing gas wall-hung boiler. Background Technology

[0002] A gas-fired boiler is a heating device that uses gaseous fuels such as natural gas and liquefied petroleum gas as energy. It generates heat through the combustion of gas and is widely used in industrial heating, commercial heating, and residential heating. With the continuous expansion of natural gas pipeline coverage, gas-fired boilers, with their advantages of being clean and environmentally friendly, having high thermal efficiency, and being easy to use, have gradually replaced traditional coal-fired and oil-fired heating equipment and become an important part of modern heating systems.

[0003] In the field of residential heating, gas-fired wall-hung boilers, as a type of gas boiler, have been rapidly popularized and applied in urban residential areas due to their compact size, wall-mountable installation, and ease of operation. Existing gas-fired wall-hung boilers mainly employ heat exchange technology. During operation, gas enters the burner through a gas valve, mixes with air, and burns to produce high-temperature flue gas. The flue gas flows through a heat exchanger, transferring heat to the heating circulating water. The heated circulating water is then pumped to underfloor heating or radiators for heat dissipation and heating. The returned water re-enters the boiler for reheating, forming a closed-loop system.

[0004] However, existing gas-fired wall-hung boilers have significant shortcomings in flue gas heat recovery. Because they only have a single-stage heat exchanger, the flue gas temperature remains high after heat exchange with the circulating water, typically around 150-200℃. At this temperature, the flue gas not only contains a large amount of sensible heat, but more importantly, the water vapor produced by combustion is still in a gaseous state, and its latent heat of condensation is completely unutilized. This high-temperature flue gas is directly discharged outdoors, resulting in a waste of approximately 10-15% of the heat, causing the overall thermal efficiency to remain at only 85-90%. For users, lower thermal efficiency means that more gas needs to be consumed to achieve the same heating effect, leading to higher long-term operating costs. Therefore, there is an urgent need to add a dedicated condensing heat exchange structure to further reduce the flue gas temperature below the dew point, recovering the latent heat released by water vapor condensation, thereby significantly improving the overall thermal efficiency of the wall-hung boiler and reducing user operating costs.

[0005] No effective solutions have yet been proposed to address the problems in the relevant technologies. Utility Model Content

[0006] In view of the problems in the related technologies, this utility model proposes a condensing gas wall-hung boiler to overcome the above-mentioned technical problems existing in the existing related technologies.

[0007] Therefore, the specific technical solution adopted by this utility model is as follows: A condensing gas-fired wall-hung boiler includes: a shell for housing and protecting internal components and forming a combustion chamber; a gas boiler platform located at the bottom of the shell for supporting the burner and forming a stable combustion platform; a burner located through the middle of the gas boiler platform for burning gas to generate high-temperature flue gas; a main heat exchanger located inside the shell and at the top of the burner for utilizing the sensible heat of the high-temperature flue gas and transferring the heat to the heating circulating water; a first condensing heat exchanger located inside the shell and at the top of one side of the main heat exchanger for performing first-stage condensing heat exchange on the flue gas and recovering the latent heat of the flue gas for initial preheating of the heating circulating water; a second condensing heat exchanger located inside the shell and at the top of the other side of the main heat exchanger for performing second-stage condensing heat exchange on the flue gas and recovering the latent heat of the flue gas for secondary preheating of the heating circulating water; a circulating water pump fixedly located on one side of the gas boiler platform for providing power for the flow of the heating circulating water; and a controller located at one end of the gas boiler platform for receiving commands and controlling the operating status of the wall-hung boiler.

[0008] Furthermore, a flue pipe is provided at the top of the housing; a power interface box connected to the controller is provided on one side of the housing; and a gas inlet pipe connected to the gas stove is provided at the middle of the bottom of the housing.

[0009] Furthermore, an inlet valve connected to a circulating water pump is provided on one side of the bottom of the casing, which is used to connect to an external return water pipeline and supply water to the circulating water pump; an outlet valve connected to the main heat exchanger is provided on the other side of the bottom of the casing, which is used to output the hot water heated by the main heat exchanger to the external heating system.

[0010] Furthermore, the main heat exchanger includes a support frame fixedly installed on the top of the gas furnace platform to support and fix the main heat exchanger; the top of the support frame is provided with several heat exchange plates arranged in a linear manner, and spiral coils are provided between the heat exchange plates.

[0011] Furthermore, the outlet end of the upper spiral coil is connected to the inlet end of the adjacent lower spiral coil in sequence through a connecting pipe, so that heating water flows from the top through each layer of spiral coil and out from the bottom. The top of the heat exchange plate is provided with several linearly distributed flue gas through holes, and the positions of the flue gas through holes are staggered from the positions of the annular pipes of the two adjacent spiral coils. The flue gas through holes are used to allow the high-temperature flue gas generated by the burner to pass upward through each layer of heat exchange plate and uniformly heat the circulating water in each layer of spiral coil, so as to realize countercurrent heat exchange between flue gas and circulating water.

[0012] Furthermore, the inlet end of the spiral coil located at the top, away from the gas stove, is connected to the second condensing heat exchanger via a pipe to receive the preheated circulating water from the second condensing heat exchanger as the inlet water for the main heat exchanger; the outlet end of the spiral coil located at the bottom, near the gas stove, is connected to the outlet valve via a pipe to transport the high-temperature hot water circulating water fully heated by the main heat exchanger to the external heating system.

[0013] Furthermore, the first condensing heat exchanger includes a mounting base plate disposed on the top of one side of the main heat exchanger, and heat exchange shells are disposed on both sides of the mounting base plate. A condensing heat exchange coil is disposed through the inner side of the heat exchange shell. A U-shaped three-way pipe is disposed at one end of the two sets of condensing heat exchange coils. One end of the U-shaped three-way pipe is connected to a circulating water pump. The other end of the two sets of condensing heat exchange coils is connected to the second condensing heat exchanger through a pipe.

[0014] Furthermore, the first condensing heat exchanger and the second condensing heat exchanger have the same structure and are arranged diagonally and centrally symmetrically. This allows the circulating water to flow sequentially through the first and second condensing heat exchangers for staged preheating before entering the main heat exchanger for heating, thereby realizing the recovery of latent heat of condensation.

[0015] The beneficial effects of this utility model are as follows: (1) The condensing gas wall-hung boiler provided by this utility model constructs a two-stage series condensing heat exchange system by symmetrically setting the first condensing heat exchanger and the second condensing heat exchanger on the top of both sides of the main heat exchanger. This allows the low-temperature circulating water returning from the external heating system to flow through the first condensing heat exchanger and the second condensing heat exchanger in sequence before entering the main heat exchanger, and to fully contact and exchange heat with the medium-temperature flue gas rising from both sides of the main heat exchanger.

[0016] (2) This utility model reduces the flue gas temperature to below the dew point, causing the water vapor in the flue gas to condense into liquid water on the surface of the condensing heat exchange coil and release a large amount of latent heat of condensation. This part of the heat that would have been wasted with the high-temperature flue gas is effectively recovered and utilized, so that the circulating water is preheated to 60-70°C before entering the main heat exchanger, which significantly reduces the heating burden of the main heat exchanger. At the same time, it reduces the exhaust temperature and the water vapor content in the flue gas, thereby increasing the overall thermal efficiency of the wall-hung boiler from the traditional 85-90% to more than 95%. This solves the problem of insufficient utilization of sensible heat and latent heat of condensation, low thermal efficiency and high gas consumption in gas wall-hung boilers due to the single-stage heat exchanger. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a structural schematic diagram of a condensing gas wall-hung boiler according to an embodiment of the present utility model; Figure 2 This is a partial structural schematic diagram of a condensing gas wall-hung boiler according to an embodiment of the present utility model; Figure 3 This is a schematic diagram of the structure of the gas boiler platform in a condensing gas wall-hung boiler according to an embodiment of the present utility model; Figure 4 This is a partial structural schematic diagram of the main heat exchanger in a condensing gas wall-hung boiler according to an embodiment of the present utility model; Figure 5 This is a partial structural schematic diagram of the main heat exchanger in a condensing gas wall-hung boiler according to an embodiment of the present utility model from another angle; Figure 6 This is a schematic diagram of the structure of the second condensing heat exchanger in a condensing gas wall-hung boiler according to an embodiment of the present utility model; Figure 7 This is a partial structural schematic diagram of the first condensing heat exchanger in a condensing gas wall-hung boiler according to an embodiment of the present utility model; Figure 8 This is a schematic diagram of the structure of the first condensing heat exchanger in a condensing gas wall-hung boiler according to an embodiment of the present utility model.

[0019] In the picture: 1. Shell; 2. Gas stove platform; 3. Burner; 4. Main heat exchanger; 401. Support frame; 402. Heat exchange plate; 403. Spiral coil; 404. Flue gas vent; 5. First condensing heat exchanger; 501. Mounting base plate; 502. Heat exchange shell; 503. Condensing heat exchange coil; 504. U-shaped three-way pipe; 6. Second condensing heat exchanger; 7. Circulating water pump; 8. Controller; 9. Exhaust pipe; 10. Power interface box; 11. Gas inlet pipe; 12. Water inlet valve; 13. Water outlet valve. Detailed Implementation

[0020] To further illustrate the various embodiments, the present invention provides accompanying drawings, which are part of the disclosure of the present invention. These drawings are mainly used to illustrate the embodiments and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these contents, those skilled in the art should be able to understand other possible implementation methods and the advantages of the present invention. The components in the figures are not drawn to scale, and similar component symbols are usually used to represent similar components.

[0021] According to an embodiment of the present invention, a condensing gas wall-hung boiler is provided.

[0022] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments, such as... Figures 1-8 As shown, the condensing gas wall-hung boiler according to an embodiment of the present invention includes: Housing 1, used to house and protect internal components and form a combustion chamber; The gas-fired furnace platform 2 is located at the bottom of the shell 1 and is used to support the burner 3 and form a stable combustion platform; Burner 3 is installed through the middle of the gas furnace platform 2 and is used to burn gas to produce high-temperature flue gas; The main heat exchanger 4 is located inside the shell 1 and at the top of the burner 3. It is used to utilize the sensible heat of the high-temperature flue gas and transfer the heat to the heating circulating water. The first condensing heat exchanger 5 is located inside the shell 1 and on the top of one side of the main heat exchanger 4. It is used for the first stage of condensing heat exchange of flue gas and recovering the latent heat of flue gas to preheat the heating circulating water for the first time. The second condensing heat exchanger 6 is located inside the shell 1 and on the top of the other side of the main heat exchanger 4. It is used for the second-stage condensing heat exchange of flue gas to recover the latent heat of flue gas for secondary preheating of heating circulating water. The circulating water pump 7 is fixedly installed on one side of the gas boiler platform 2 to provide power for the flow of heating circulating water; The controller 8 is located at one end of the gas boiler platform 2 and is used to receive instructions and control the working status of the wall-hung boiler.

[0023] In one embodiment, a flue pipe 9 is provided at the top of the housing 1; a power interface box 10 connected to the controller 8 is provided on one side of the housing 1; and a gas inlet pipe 11 connected to the gas stove 2 is provided at the middle of the bottom of the housing 1.

[0024] It should be noted that the bottom end of the exhaust pipe 9 is equipped with a fan that is fixedly connected to the top of the inner side of the housing 1. The fan is used to forcibly draw in the low-temperature flue gas after combustion and discharge it from the housing 1 through the exhaust pipe 9. One end of the gas inlet pipe 11 is equipped with a gas shut-off valve, which is used to control the on / off of the gas supply and provide safety protection.

[0025] In specific applications, burner 3 adopts a premixed gas burner or an atmospheric gas burner. Burner 3 includes a gas nozzle, an air mixing chamber, a burner array, and an igniter. Gas enters the gas nozzle through the gas inlet pipe 11 and mixes with air in a certain proportion in the air mixing chamber to form a combustible mixture. The mixture is ejected from multiple flame holes in the burner array and ignited by the igniter to form a stable flame. The igniter adopts a high-voltage pulse igniter or an electronic igniter, which ignites the combustible mixture by generating a high-voltage electric spark. The burner array of burner 3 is made of stainless steel or cast iron, and the flame holes are evenly distributed to ensure complete combustion. The structure, ignition method, and gas-air mixing principle of burner 3 described above are all existing technologies and can be implemented by those skilled in the art using conventional technical means, and will not be elaborated here.

[0026] It should also be noted that controller 8 uses a programmable logic controller (PLC) or a microcontroller (such as an STM32 series or an Arduino series). Controller 8 is electrically connected to the circulating water pump 7, the gas shut-off valve, the igniter of the burner 3, and the fan at the bottom of the exhaust pipe 9 via cables. The input terminals of controller 8 are connected to multiple temperature sensors (such as NTC thermistors or PT1000 platinum resistance thermometers). These temperature sensors are installed at the outlet of the main heat exchanger 4, on the pipes of the first condensing heat exchanger 5 and the second condensing heat exchanger 6, respectively, to collect the circulating water temperature and flue gas temperature in real time. Data; The controller 8 outputs control signals according to the collected temperature data and a preset control algorithm (such as PID control algorithm), drives the solenoid valve switch of the gas shut-off valve and the igniter through a relay or solid-state relay, and adjusts the speed of the circulating water pump 7 and the fan through the PWM speed control module, thereby realizing the automated operation and temperature regulation of the wall-hung boiler; The controller 8 and its connection with each electronic control component, the signal acquisition and processing method of the temperature sensor, and the automatic control logic based on temperature feedback are all existing technologies, which can be implemented by those skilled in the art using conventional technical means, and will not be described in detail here.

[0027] In one embodiment, a water inlet valve 12 connected to the circulating water pump 7 is provided on one side of the bottom end of the housing 1 for connecting to the external return water pipeline and supplying water to the circulating water pump 7; a water outlet valve 13 connected to the main heat exchanger 4 is provided on the other side of the bottom end of the housing 1 for outputting the hot water heated by the main heat exchanger 4 to the external heating system.

[0028] In one embodiment, the main heat exchanger 4 includes a support frame 401 fixedly mounted on the top of the gas boiler platform 2 for supporting and fixing the main heat exchanger 4; the top of the support frame 401 is provided with a plurality of linearly arranged heat exchange plates 402, and spiral coils 403 are provided between the plurality of heat exchange plates 402; the water outlet end of the upper spiral coil 403 is sequentially connected to the water inlet end of the adjacent lower spiral coil 403 through a connecting pipe, so as to realize that heating water flows from the top through each layer of spiral coils 403 sequentially and flows out from the bottom; the top of the heat exchange plate 402 is provided with a plurality of linearly distributed flue gas through holes 404, and the positions of the flue gas through holes 404 are adjacent to the two layers of spiral coils 403. The positions of the annular pipes 3 are staggered; the flue gas through-hole 404 is used to allow the high-temperature flue gas generated by the burner 3 to pass upward through each heat exchange plate 402 and uniformly heat the circulating water in each spiral coil 403, so as to realize the counter-current heat exchange between flue gas and circulating water; the water inlet end of the spiral coil 403 located away from the gas furnace platform 2 and at the top is connected to the second condensing heat exchanger 6 through a pipe, and is used to receive the circulating water preheated by the second condensing heat exchanger 6 as the water inlet of the main heat exchanger 4; the water outlet end of the spiral coil 403 located near the gas furnace platform 2 and at the bottom is connected to the water outlet valve 13 through a pipe, and is used to transport the high-temperature hot water circulating water fully heated by the main heat exchanger 4 to the external heating system.

[0029] It should be noted that the support frame 401 is made of high-temperature resistant metal material (such as stainless steel or heat-resistant alloy steel) to bear the overall weight of the main heat exchanger 4 and the thermal stress of the high-temperature flue gas. At the same time, the open structure of the support frame 401 allows the high-temperature flue gas to flow freely upward from the burner 3, ensuring that the flue gas can fully pass through each heat exchange plate 402 and the spiral coil 403. The heat exchange plate 402 is made of metal material with high thermal conductivity (such as copper or aluminum alloy) to increase the contact area with the flue gas and improve the heat exchange efficiency. The spiral coil 403 is made of copper tube or stainless steel tube. The equal spacing between several heat exchange plates 402 ensures both smooth flow of flue gas and sufficient heat exchange time. Furthermore, the uniformly opened flue gas through holes 404 allow the flue gas to be evenly dispersed and pass through each heat exchange plate 402 in sequence.

[0030] It should also be noted that the bottom end of the support frame 401 is fixedly connected to the top end of the gas furnace platform 2 by welding; several heat exchange plates 402 are stacked sequentially at a predetermined interval on the top end of the support frame 401, and each layer of heat exchange plates 402 is fixed to the support frame 401 by welding; the spiral coils 403 are respectively embedded in the space between two adjacent layers of heat exchange plates 402 and are fixedly connected to the heat exchange plates 402 by welding, so that the support frame 401, heat exchange plates 402 and spiral coils 403 form a stable overall structure, ensuring the structural strength and heat exchange performance of the main heat exchanger 4 in a high-temperature environment.

[0031] The working principle of the main heat exchanger 4 is as follows: Preheated circulating water (temperature approximately 60-70℃) flowing out from the second condensing heat exchanger 6 enters the inlet of the spiral coil 403 located at the top of the main heat exchanger 4 through a pipe. Under the action of gravity and the pressure provided by the circulating water pump 7, the circulating water flows from top to bottom through each layer of spiral coil 403. At the same time, high-temperature flue gas (temperature approximately above 1000℃) generated by the burner 3 flows upward from the bottom of the main heat exchanger 4, passing through the flue gas passages 404 on the heat exchange plates 402 and passing through each layer of heat exchange plates 402 in sequence. During this process, the high-temperature flue gas passes through the heat exchange plates 402 and the spiral coil 403. The metal wall of the 03 transfers heat to the circulating water flowing inside the pipe. The flue gas temperature gradually decreases to 150-200℃, while the circulating water temperature gradually increases to 70-80℃. Since the flow direction of the circulating water is opposite to that of the flue gas, countercurrent heat exchange is formed. This heat exchange method keeps the temperature gradient in an optimal state, that is, colder water corresponds to colder flue gas, and hotter water corresponds to hotter flue gas, thereby maximizing the heat exchange efficiency. The high-temperature circulating water, which is fully heated by the main heat exchanger 4, flows out from the outlet end of the bottom spiral coil 403, is connected to the outlet valve 13 through a pipe, and is finally delivered to the external heating system.

[0032] In one embodiment, the first condensing heat exchanger 5 includes a mounting base 501 disposed on the top of one side of the main heat exchanger 4. Heat exchange shells 502 are disposed on both sides of the mounting base 501, and condensing heat exchange coils 503 are disposed through the inner side of the heat exchange shells 502. A U-shaped three-way pipe 504 is disposed at one end of the two sets of condensing heat exchange coils 503. One end of the U-shaped three-way pipe 504 is connected to the circulating water pump 7. The other end of the two sets of condensing heat exchange coils 503 is connected to the second condensing heat exchanger 6 through a pipe. The first condensing heat exchanger 5 and the second condensing heat exchanger 6 have the same structure and are arranged diagonally and centrally symmetrically, so that the circulating water flows through the first condensing heat exchanger 5 and the second condensing heat exchanger 6 in sequence for staged preheating, and enters the main heat exchanger 4 for main heating, so as to realize the recovery of latent heat of condensation.

[0033] It should be noted that the mounting base plate 501 is made of corrosion-resistant metal material (e.g., stainless steel), and its surface is treated with anti-corrosion to resist the corrosive effect of condensate. The mounting base plate 501 is fixed to the side wall of the main heat exchanger 4 by welding. The heat exchange shell 502 is a closed structure and is made of metal material with high thermal conductivity (e.g., copper or aluminum alloy), so that the medium-temperature flue gas rising from both sides of the main heat exchanger 4 can fully exchange heat with the outer surface of the condensing heat exchange coil 503. The condensing heat exchange coil 503 is made of copper tube or stainless steel tube and is fixed to the inner side of the heat exchange shell 502 by welding, which increases the contact area with the flue gas and the heat exchange time.

[0034] It should also be noted that the first condensing heat exchanger 5 and the second condensing heat exchanger 6 adopt the same structural design and are installed on the top of the two sides of the main heat exchanger 4 in a diagonally symmetrical manner. The two are connected by pipes to form a series water circuit, so that the circulating water flows through the first condensing heat exchanger 5 and the second condensing heat exchanger 6 in sequence for staged preheating, thereby maximizing the recovery of latent heat of condensation. The bottom of the shell 1 is provided with water collection tanks on both sides of the gas furnace platform 2 to collect a small amount of condensate dripping from the outer surface of the heat exchange shell 502 after the flue gas condenses. The bottom of the water collection tank is provided with a drain plug, which can be manually opened periodically to drain the condensate in the water collection tank.

[0035] The working principle of the first condensing heat exchanger 5 and the second condensing heat exchanger 6 is as follows: Low-temperature return water (temperature approximately 40-50℃) from the external heating system enters the circulating water pump 7 through the inlet valve 12. Driven by the circulating water pump 7, the low-temperature return water enters the U-shaped three-way pipe 504 at the bottom of the first condensing heat exchanger 5 through the pipe, and is then diverted into the condensing heat exchange coils 503 on both sides. At the same time, the medium-temperature flue gas (temperature approximately 150-200℃) rising and escaping from both sides of the main heat exchanger 4 comes into contact with the first condensing heat exchanger 6. In the heat exchange shell 502 of the heat exchanger 5, the flue gas exchanges heat with the outer surface of the condensing heat exchange coil 503 inside the heat exchange shell 502. Since the temperature of the circulating water inside the coil is much lower than the dew point temperature of the flue gas (approximately 55-60℃), the water vapor in the flue gas condenses into liquid water on the surface of the coil and releases a large amount of latent heat of condensation. This latent heat is transferred to the circulating water inside the coil through the coil wall, causing the temperature of the circulating water to rise to approximately 50-55℃, while the temperature of the flue gas drops to approximately 80-100℃. After passing through the first condensing heat exchanger 5... The preheated circulating water flows out from the other end of the two condensing heat exchange coils 503 and enters the condensing heat exchange coil 503 at the bottom of the second condensing heat exchanger 6 through a pipe. In the second condensing heat exchanger 6, the circulating water continues to undergo a second stage of condensing heat exchange with the medium-temperature flue gas. The temperature of the circulating water further increases to about 60-70℃, while the temperature of the flue gas further decreases to about 55-65℃. The residual water vapor in the flue gas continues to condense and release latent heat. After being preheated by two stages of condensing heat exchange, the circulating water flows out from the top of the second condensing heat exchanger 6 through the U-shaped outlet. The three-way pipe 504 flows out and enters the spiral coil 403 at the top of the main heat exchanger 4 for final heating; while the low-temperature flue gas (temperature of about 55-65℃) that has completed condensation heat exchange is discharged from the shell 1 by the fan through the exhaust pipe 9; through this two-stage series condensation heat exchange method, the sensible heat and latent heat of the flue gas are maximized for recovery, which not only increases the inlet temperature of the circulating water, but also reduces the heat loss of the exhaust gas, so that the thermal efficiency of the wall-hung boiler can reach more than 95%, achieving the design goal of energy saving and environmental protection.

[0036] To facilitate understanding of the above-mentioned technical solutions of this utility model, the working principle or operation method of this utility model in actual process will be described in detail below.

[0037] In practical applications, the user sets the desired heating temperature and operating mode through the controller 8. The controller 8 starts the circulating water pump 7 and opens the gas shut-off valve according to the set parameters. Gas enters the burner 3 through the gas inlet pipe 11, mixes with air, and ignites, producing high-temperature flue gas with a temperature exceeding 1000℃. Low-temperature return water (approximately 40-50℃) from the external heating system enters the circulating water pump 7 through the inlet valve 12. Driven by the circulating water pump 7, the low-temperature return water first enters the first condensing heat exchanger 5, where it undergoes first-stage condensation heat exchange with the medium-temperature flue gas (approximately 150-200℃) rising from both sides of the main heat exchanger 4. Water vapor in the flue gas begins to condense and release latent heat, causing the circulating water temperature to rise to approximately 50-55℃ and the flue gas temperature to drop to approximately 80-100℃. After passing through the first condensing heat exchanger 5... The hot circulating water then enters the second condensing heat exchanger 6 for the second stage of condensation and heat exchange. The temperature of the circulating water further rises to about 60-70℃, while the temperature of the flue gas further drops to about 55-65℃. After being preheated by the two stages of condensation, the circulating water flows out from the top of the second condensing heat exchanger 6 and enters the spiral coil 403 at the top of the main heat exchanger 4 through a pipe. Under the combined action of gravity and water pump pressure, the circulating water flows from top to bottom through each layer of spiral coil 403, and exchanges heat with the high-temperature flue gas flowing upward from the burner 3 in a countercurrent manner. After absorbing the sensible heat of the high-temperature flue gas, the temperature of the circulating water rises to 70-80℃, while the temperature of the flue gas drops to 150-200℃. The fully heated high-temperature circulating water flows out from the bottom of the main heat exchanger 4 and is transported to the external heating system through the outlet valve 13 for heating, completing a complete heating cycle. Meanwhile, the flue gas cooled by the main heat exchanger 4 continues to escape upward from both sides and contact the heat exchange shell 502 of the first condensing heat exchanger 5 and the second condensing heat exchanger 6. After further releasing sensible and latent heat during the condensation heat exchange process, the flue gas temperature drops to 55-65℃ and is finally forced out of the shell 1 to the outside by the fan at the top of the exhaust pipe 9.

[0038] In this utility model, unless otherwise explicitly specified and limited, the terms "installation", "setting", "connection", "fixing", "screw connection", etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal connection of two components or the interaction between two components. Unless otherwise explicitly limited, those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0039] 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 condensing gas-fired wall-mounted boiler, characterized in that, include: The housing (1) is used to house and protect the internal components and to form the combustion chamber; A gas-fired stove platform (2) is located at the bottom of the housing (1) and is used to support the burner (3) and form a stable combustion platform; The burner (3) is installed through the middle of the gas furnace platform (2) and is used to burn gas to generate high-temperature flue gas; The main heat exchanger (4) is located inside the shell (1) and on top of the burner (3) to utilize the sensible heat of the high-temperature flue gas and transfer the heat to the heating circulating water. The first condensing heat exchanger (5) is located inside the shell (1) and on the top of one side of the main heat exchanger (4). It is used to perform first-stage condensing heat exchange on the flue gas and recover the latent heat of the flue gas to preheat the heating circulating water for the first time. The second condensing heat exchanger (6) is located inside the shell (1) and on the top of the other side of the main heat exchanger (4). It is used to perform second-stage condensing heat exchange on the flue gas and recover the latent heat of the flue gas to preheat the heating circulating water for a second time. A circulating water pump (7) is fixedly installed on one side of the gas boiler platform (2) to provide power for the flow of heating circulating water; The controller (8) is located at one end of the gas boiler platform (2) and is used to receive instructions and control the working status of the wall-hung boiler.

2. A condensing gas-fired wall-mounted boiler according to claim 1, characterized in that, The top of the housing (1) is provided with a smoke exhaust pipe (9). A power interface box (10) connected to the controller (8) is provided on one side of the housing (1). The bottom center of the housing (1) is provided with a gas inlet pipe (11) that is connected to the gas stove (2).

3. A condensing gas-fired wall-mounted boiler according to claim 2, characterized in that, The bottom side of the housing (1) is provided with an inlet valve (12) connected to the circulating water pump (7) for connecting the external return water pipeline and supplying water to the circulating water pump (7); A water outlet valve (13) connected to the main heat exchanger (4) is provided on the other side of the bottom of the housing (1) for outputting the hot water heated by the main heat exchanger (4) to the external heating system.

4. A condensing gas-fired wall-mounted boiler according to claim 3, characterized in that, The main heat exchanger (4) includes a support frame (401) fixedly installed at the top of the gas furnace platform (2) for supporting and fixing the main heat exchanger (4); the top of the support frame (401) is provided with a plurality of heat exchange plates (402) arranged in a linear manner, and a spiral coil (403) is provided between the plurality of heat exchange plates (402).

5. A condensing gas-fired wall-mounted boiler according to claim 4, characterized in that, The outlet end of the upper spiral coil (403) is connected to the inlet end of the adjacent lower spiral coil (403) in sequence through a connecting pipe, so as to realize that heating water flows from the top through each layer of spiral coil (403) and flows out from the bottom. The top of the heat exchange plate (402) is provided with a number of linearly distributed flue gas through holes (404), and the position of the flue gas through holes (404) is staggered from the position of the annular pipeline of the two adjacent spiral coils (403); the flue gas through holes (404) are used to allow the high-temperature flue gas generated by the burner (3) to pass upward through each heat exchange plate (402) and uniformly heat the circulating water in each spiral coil (403) to achieve countercurrent heat exchange between flue gas and circulating water.

6. A condensing gas-fired wall-mounted boiler according to claim 5, characterized in that, The water inlet of the spiral coil (403) located away from the gas furnace platform (2) and at the top is connected to the second condensing heat exchanger (6) through a pipe to receive the circulating water preheated by the second condensing heat exchanger (6) as the water inlet of the main heat exchanger (4); The outlet end of the spiral coil (403) located near the bottom of the gas furnace platform (2) is connected to the outlet valve (13) through a pipe to transport the high-temperature hot water circulating water after being fully heated by the main heat exchanger (4) to the external heating system.

7. A condensing gas-fired wall-mounted boiler according to claim 1, characterized in that, The first condensing heat exchanger (5) includes a mounting base plate (501) disposed on the top of one side of the main heat exchanger (4). Heat exchange shells (502) are disposed on both sides of the mounting base plate (501), and a condensing heat exchange coil (503) is disposed through the inner side of the heat exchange shell (502). One end of each of the two sets of condensing heat exchange coils (503) is provided with a U-shaped three-way pipe (504), one end of which is connected to the circulating water pump (7); the other end of the two sets of condensing heat exchange coils (503) is connected to the second condensing heat exchanger (6) through a pipe.

8. A condensing gas-fired wall-mounted boiler according to claim 7, characterized in that, The first condensing heat exchanger (5) and the second condensing heat exchanger (6) have the same structure and are arranged diagonally and centrally symmetrically. They are used to allow circulating water to flow through the first condensing heat exchanger (5) and the second condensing heat exchanger (6) in sequence for stage-by-stage preheating, and then enter the main heat exchanger (4) for heating, so as to realize the recovery of latent heat of condensation.

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