A modular assembly of large water-cooled premixed combustion boiler

Abstract

The present invention discloses a modularly assembled large-scale water-cooled premixed combustion boiler, which belongs to the field of gas boilers. A modularly assembled large-scale water-cooled premixed combustion boiler comprises: a boiler module, the boiler module comprises an upper cylinder, a lower cylinder, a water group pipe, a membrane wall group and a furnace area, and also comprises: an economizer module, the economizer module is provided with a smoke inlet and a smoke exhaust port; a smoke exhaust area is provided on one side of the membrane wall group; a connecting pipe is detachably connected between the smoke inlet and the smoke exhaust area; a superheater, the superheater comprises a second heat exchange tube, a hot gas inlet pipe and a hot gas outlet pipe; the integral boiler of the present invention adopts a modular assembly form, cancels the traditional header design, and an external interface is provided on each module, which is portable for installation and convenient for delivery, reduces the difficulty of assembly and the workload on site, and can be installed in different positions according to the customer's requirements for the superheated steam temperature.

Description

Technical Field

[0001] The invention relates to the technical field of gas boilers, and in particular to a modularly assembled large-scale water-cooled premixed combustion boiler. Background Art

[0002] The water-cooled premixed combustion boiler achieves the ideal combustion state and the ideal emission state by premixing with a specified amount of air in advance. In terms of boilers, traditional boilers use flue gas convection heat transfer, which has low heat exchange efficiency and requires a large heat exchange area. Traditional boilers are large in size, complicated in structure, and consume a lot of metal.

[0003] In the prior art, a patent with publication number: CN117387050B and publication date: 2024-02-27 discloses a vertical water tube boiler suitable for a water-cooled premixed flat burner, including a boiler furnace body, wherein a first furnace body, a second furnace body, and a water tube group are arranged in the boiler furnace body, an upper partition is arranged at the bottom of the first furnace body, and a lower partition is arranged at the top of the second furnace body; an isolation belt is arranged on the outside of the water tube group, the top of the water tube group passes through the upper partition to communicate with the first furnace body, and the bottom of the water tube group passes through the lower partition to communicate with the second furnace body; an air intake device is arranged on one side of the water tube group, and the air intake device is used to pass the intake gas to the water tube group; there is no need to strengthen the first furnace body and the second furnace body by adding an outer cylinder, which greatly reduces the boiler steel consumption.

[0004] The above patent effectively solves the problems of large size and high metal consumption of traditional boilers. When customers have higher requirements for the superheated steam temperature, the steam needs to be heated. When customers have lower requirements for the superheated steam temperature, the steam needs to be cooled. However, the boiler in the above patent is an integrated setting, and customization is required when configuring the superheater according to customer requirements, which cannot meet customer needs in a timely manner. At the same time, the current filtration is shipped in containers, which is not convenient for transportation. Some are also shipped in bulk, but the workload and difficulty of on-site assembly are large. Summary of the invention

[0005] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a modularly assembled large water-cooled premixed combustion boiler that can overcome the above problems or at least partially solve the above problems.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A modularly assembled large-scale water-cooled premixed combustion boiler comprises: a boiler module, the boiler module comprises an upper cylinder, a lower cylinder, a water group tube, a membrane wall group and a furnace area, and also comprises: an economizer module, the economizer module is provided with a smoke inlet and a smoke exhaust port; a smoke exhaust area is provided on one side of the membrane wall group; a connecting pipe is detachably connected between the smoke inlet and the smoke exhaust area; a superheater, the superheater comprises a second heat exchange tube, a hot gas inlet tube and a hot gas outlet tube; when the required superheated steam temperature is greater than the steam temperature output by the upper cylinder, the furnace area is made into a furnace module, and the superheater is arranged in the furnace of the furnace module; when the required superheated steam temperature is less than the steam temperature output by the upper cylinder, the superheater is arranged in the economizer module, and a reflux tube is arranged at the lower end of the second heat exchange tube.

[0008] Preferably, the upper cylinder and the lower cylinder are both configured as semicircular cylinders, the upper cylinder is sequentially provided with a liquid level gauge tube seat, an upper inspection port, a vent pipe, an exhaust pipe, a safety valve and a water inlet, and the lower cylinder is provided with a lower inspection port, a drain and a drain port.

[0009] In order to reduce the consumption of steel materials, the membrane wall group further comprises a plurality of membrane wall tubes equidistantly arranged between the upper cylinder and the lower cylinder, and a steel plate is arranged between two adjacent membrane wall tubes.

[0010] Furthermore, a combustion surface is provided on one side of the membrane wall group, the combustion surface matches the furnace area, a mixing chamber is provided in the furnace area, and an air uniforming orifice plate, a combustion surface tube group and a flame arrester are provided between the mixing chamber and the combustion surface.

[0011] Preferably, the water group tubes include a plurality of groups of large-diameter light tubes, small-diameter light tubes and spiral fin tubes arranged in sequence, wherein the large-diameter light tubes are arranged on a side close to the furnace area.

[0012] In order to facilitate sufficient heat exchange of the heat in the flue gas, further, an installation gap is provided between two adjacent groups of spiral finned tubes, a baffle is provided in the installation gap, and a plurality of the baffles form a serpentine air passage.

[0013] In order to facilitate the contact between the smoke and the spiral fin tube, further, the baffle is configured to be in a wave shape matching the spiral fin tube.

[0014] In order to prevent excessive pressure in the drum, the baffle is further provided with a plurality of equally spaced pressure relief holes.

[0015] In order to facilitate the uniform flow of smoke and avoid smoke dead corners, a gradually increasing air gap is further provided between the small diameter light tubes located on both sides of the combustion surface.

[0016] In order to facilitate the preheating of the water for air supply, further, a first heat exchange tube is provided in the economizer module, a water inlet pipe is provided at one end of the first heat exchange tube, and a water outlet pipe is provided at the other end of the first heat exchange tube.

[0017] Compared with the prior art, the present invention provides a modularly assembled large water-cooled premixed combustion boiler, which has the following beneficial effects:

[0018] 1. This modularly assembled large water-cooled premixed combustion boiler is delivered in bulk. When the customer has a high requirement for the superheated steam temperature, the steam temperature cannot meet the customer's needs. The furnace area is made into a furnace module, and the superheater is installed in the furnace for secondary heating to meet the customer's steam temperature requirements. When the customer has a low requirement for the superheated steam temperature, the superheater is installed in the economizer module, and the steam is discharged for use after heat exchange and cooling to the specified temperature in the economizer, thereby meeting the needs of different customers.

[0019] 2. The modularly assembled large water-cooled premixed combustion boiler adopts modular assembly for the overall boiler, eliminating the traditional header design. It is mainly composed of boiler module, economizer module and superheater. An external steam drum can be set according to the actual tonnage, and the volume of the external steam drum can be customized according to the tonnage. Each module is provided with an external interface, which is easy to install and ship.

[0020] 3. The modularly assembled large water-cooled premixed combustion boiler adopts modular assembly for the overall boiler, eliminating the traditional header design. It is mainly composed of boiler module, economizer module and superheater. An external steam drum can be set according to the actual tonnage, and the volume of the external steam drum is customized according to the tonnage. An external interface is set on each module, which is easy to install and transport, and easy to ship, reducing the difficulty of assembly and on-site workload.

[0021] The parts not involved in the device are the same as the existing technology or can be implemented by the existing technology. The overall boiler of the present invention adopts the form of modular assembly, cancels the traditional header design, and an external interface is set on each module. It is easy to install and ship, reducing the difficulty of assembly and on-site workload. At the same time, the superheater can be installed in different positions according to the customer's requirements for the superheated steam temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the structure of a boiler module, an economizer module and a superheater in a modular assembly of a large water-cooled premixed combustion boiler proposed by the present invention;

[0023] Figure 2 A schematic diagram of a first heat exchange tube in an economizer module in a large water-cooled premixed combustion boiler in a modular assembly proposed by the present invention;

[0024] Figure 3 A schematic diagram of a modular assembly of a superheater in a large water-cooled premixed combustion boiler proposed by the present invention;

[0025] Figure 4 This is a schematic structural diagram of a boiler module in a modularly assembled large-scale water-cooled premixed combustion boiler proposed by the present invention;

[0026] Figure 5 This is a schematic structural diagram of a furnace module in a modularly assembled large water-cooled premixed combustion boiler proposed by the present invention;

[0027] Figure 6 A schematic diagram of a first heat exchange tube and a second heat exchange tube in a modular assembly of a large water-cooled premixed combustion boiler proposed by the present invention;

[0028] Figure 7 Schematic cross-sectional view of the water group pipe in Example 3 of the present invention;

[0029] Figure 8 Schematic cross-sectional view of a water group pipe in Example 2 of the present invention;

[0030] Fig. 9 Schematic cross-sectional view of a water group pipe in Example 4 of the present invention;

[0031] Fig.10 It is a schematic diagram of two combustion surfaces in the present invention;

[0032] Fig.11 It is a structural schematic diagram of the baffle in the present invention;

[0033] Fig.12 Schematic diagram of the structure of the small diameter light pipe in Example 3 of the present invention.

[0034] In the figure: 1. Upper cylinder; 101. Upper inspection port; 102. Vent pipe; 103. Exhaust pipe; 104. Safety valve; 105. Water inlet; 106. Liquid level gauge tube seat; 2. Lower cylinder; 201. Lower inspection port; 202. Drain; 203. Drain port; 3. Furnace area; 4. Water group pipe; 401. Large diameter light pipe; 402. Small diameter light pipe; 403. Spiral fin tube; 404. Air gap; 405 , installation gap; 406, baffle; 407, pressure relief hole; 5, membrane wall group; 501, membrane wall tube; 502, steel plate; 503, smoke exhaust area; 6, energy saver module; 601, smoke inlet; 602, smoke exhaust port; 603, connecting pipe; 604, water inlet pipe; 605, water outlet pipe; 606, first heat exchange tube; 607, hot air inlet pipe; 608, hot air outlet pipe; 609, reflux pipe; 610, second heat exchange tube. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0036] Example 1: Reference Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 and Fig.10 A modularly assembled large water-cooled premixed combustion boiler comprises: a boiler module, the boiler module comprises an upper cylinder 1, a lower cylinder 2, a water group tube 4, a membrane wall group 5 and a furnace area 3, and also comprises: an economizer module 6, the economizer module 6 is provided with a smoke inlet 601 and a smoke exhaust port 602; a smoke exhaust area 503 is provided on one side of the membrane wall group 5; a connecting pipe 603, which is detachably connected between the smoke inlet 601 and the smoke exhaust area 503; a superheater, the superheater comprises a second heat exchange tube 610, a hot gas inlet tube 607 and a hot gas outlet tube 608; when the required superheated steam temperature is greater than the steam temperature output by the upper cylinder 1, the furnace area 3 is made into a furnace module, and the superheater is arranged in the furnace of the furnace module; when the required superheated steam temperature is less than the steam temperature output by the upper cylinder 1, the superheater is arranged in the economizer module 6, and at this time, a reflux tube 609 is arranged at the lower end of the second heat exchange tube 610.

[0037] The upper cylinder 1 and the lower cylinder 2 are both welded by special-shaped heads and rectangular tube sheets.

[0038] In actual use, bulk delivery is adopted. When the customer has high requirements for the superheated steam temperature, the steam temperature cannot meet the customer's needs. The furnace area 3 is made into a furnace module, and the superheater is installed in the furnace for secondary heating to meet the customer's steam temperature requirements.

[0039] When the customer has a lower requirement for the superheated steam temperature, the steam temperature is greater than the steam temperature actually required by the customer, and the steam needs to be cooled and heat exchanged. The superheater is installed in the economizer module 6, and the steam is discharged for use after being cooled to the specified temperature through heat exchange in the economizer, thereby meeting the needs of different customers.

[0040] The overall boiler adopts modular assembly and cancels the traditional header design. It is mainly divided into boiler module, economizer module 6 and superheater. The external steam drum can be set according to the actual tonnage, and the volume of the external steam drum is customized according to the tonnage. Each module is provided with an external interface, which is easy to install and transport, and easy to ship, reducing the difficulty of assembly and on-site workload.

[0041] The upper cylinder 1 and the lower cylinder 2 are both configured as semicircular cylinders. The upper cylinder 1 is provided with a liquid level gauge tube seat 106, an upper inspection port 101, a vent pipe 102, an exhaust pipe 103, a safety valve 104 and a water inlet 105 in sequence, and the lower cylinder 2 is provided with a lower inspection port 201, a drain device 202 and a drain port 203.

[0042] The membrane wall group 5 includes a plurality of membrane wall tubes 501 equidistantly arranged between the upper cylinder 1 and the lower cylinder 2 , and a steel plate 502 is provided between two adjacent membrane wall tubes 501 .

[0043] The boiler module eliminates the need for a large furnace and the boiler drum adopts an upper cylinder 1 and a lower cylinder 2 with rectangular cross-sections, and is supported between the upper cylinder 1 and the lower cylinder 2 by a membrane wall group 5. At the same time, as a closed cylinder, the overall structure is compact, occupies a small area, has low metal steel consumption, and has high energy efficiency, which helps to save energy, reduce emissions, and reduce carbon emissions.

[0044] A combustion surface is arranged on one side of the membrane wall group 5, and the combustion surface matches the furnace area 3. A mixing chamber is arranged in the furnace area 3, and an air-distributing orifice plate, a combustion surface pipe group and a flame arrester are arranged between the mixing chamber and the combustion surface.

[0045] The combustion surface is a device for fuel distribution and combustion, and is mainly composed of a mixing chamber, an air-uniforming orifice plate, a combustion surface tube group and a flame arrester. The mixing chamber is welded with steel plates to form a cavity with open ends and closed on all sides. One side is connected to the mixer, and the other side is connected to the combustion surface tube group. An air-uniforming orifice plate is arranged inside the mixing chamber near the combustion surface tank group. The air-uniforming orifice plate is made of a steel thin plate, and a plurality of small holes are evenly opened on the steel thin plate for uniform air distribution. The combustion surface tube group is composed of a plurality of outer square and inner circular straight tubes, which are arranged in a line, and a certain gap is left between two adjacent tubes as a circulation and combustion channel for the premixed gas. The two ends of the outer square and inner circular tube are circular tube structures; a flame arrester is arranged inside the gap of the combustion surface tube group as a premixed gas injection and backfire prevention device. The flame arrester is composed of a plurality of corrugated steel thin plates stacked together, and the combustion surface is vertically arranged on one side of the membrane wall group 5.

[0046] According to the requirements, one or more combustion surfaces can be provided.

[0047] Example 2: Reference Figure 8 , Fig.10 and Fig.11 A modularly assembled large water-cooled premixed combustion boiler is basically the same as Example 1. Further, the water group pipe 4 includes multiple groups of large-diameter light pipes 401, small-diameter light pipes 402 and spiral finned tubes 403 arranged in sequence, wherein the large-diameter light pipe 401 is arranged on the side close to the furnace area 3, and multiple downcomers are arranged on the outer side of the membrane wall group 5. The downcomers are not heated, and are arranged between the upper cylinder 1 and the lower cylinder 2. The downcomers are mainly used for water reflux.

[0048] In a specific embodiment, when the boiler module is working, the flame ejected from the combustion surface first heats the large diameter light tube 401, so that the large diameter light tube 401 is quickly heated, and the hot air flows from the gap of the large diameter light tube 401 to the small diameter light tube 402 to heat the multiple small diameter light tubes 402. The large diameter light tube 401 and the small diameter light tube 402 are in a high temperature zone, so that the water in the large diameter light tube 401 and the small diameter light tube 402 is quickly heated and tends to flow upward. The spiral fin tube 403 located in the low temperature zone is heated slowly and its internal temperature is low. At this time, the water in the spiral fin tube 403 tends to flow downward, thereby realizing self-circulation, and the downward flowing water can be subjected to secondary heat absorption through the spiral fin tube 403, thereby realizing preheating of the water and full utilization of heat.

[0049] An installation gap 405 is provided between two adjacent groups of spiral fin tubes 403 , and a baffle 406 is provided in the installation gap 405 . The plurality of baffles 406 form a serpentine air passage.

[0050] In a specific embodiment, after the gas mixed with air and fuel is burned, it forms an air flow and is discharged through the smoke exhaust port 602. Since the size of the smoke exhaust port 602 is set to be small, multiple baffles 406 are used to form a serpentine air duct, and the spiral fin tube 403 is placed in the serpentine air duct. At this time, the flue gas in the boiler drum heats the small-diameter light tube 402 in the high-temperature zone and flows along the serpentine air duct. At this time, part of the heat in the flue gas is exchanged to the water in the spiral fin tube 403, thereby achieving full utilization of the heat and effectively preventing the local spiral fin tube 403 from being heated unevenly and affecting its heat exchange efficiency and heat exchange effect.

[0051] The baffle 406 is configured to be in a wave shape that matches the spiral fin tube 403 .

[0052] The baffle 406 is arranged to be wavy so that part of the gas is blown toward the spiral fin tube 403 along the tangent line of the wave, thereby effectively improving the heat exchange effect on the flue gas in the low temperature zone.

[0053] The baffle 406 is provided with a plurality of pressure relief holes 407 which are arranged at equal intervals.

[0054] A pressure relief hole 407 is provided on the baffle 406. When the air pressure on one side of the baffle 406 is too high, part of the gas is directly released to the other side through the pressure relief hole 407, thereby improving the heat exchange efficiency while improving its safety, and preventing the flue gas in the low-temperature zone from encountering the baffle 406 and then flowing back to take away the heat from the high-temperature zone.

[0055] When there are two combustion surfaces, and the area of ​​the combustion surface is consistent with the heating area of ​​the water group pipe 4, a baffle 406 is installed in the installation gap 405 to improve the heat utilization rate in the flue gas.

[0056] Example 3: Reference Figure 7 and Fig.12 A modularly assembled large water-cooled premixed combustion boiler is basically the same as Example 1. Furthermore, in order to facilitate the uniform heating of the large-diameter light pipe 401 and the small-diameter light pipe 402 in the high-temperature zone, a gradually increasing air gap 404 is provided between the small-diameter light pipes 402 located on both sides of the combustion surface.

[0057] When the combustion surface is smaller than the heating surface of the water group pipe 4, the water group pipe 4 is reasonably arranged, and the large diameter light pipe 401 is used as the main heating pipe. The smoke after passing through the large diameter light pipe 401 flows concentratedly to the smoke exhaust area 503. At this time, the amount of smoke passing through the small diameter light pipes 402 located on both sides of the combustion surface is small. By setting a gradually increasing air gap 404, part of the gas can pass evenly between two adjacent small diameter light pipes 402, so that the small diameter light pipe 402 is heated evenly, and at the same time, the heat exchange efficiency of the smoke is improved, preventing the heat of the smoke in the high temperature area from not being fully absorbed, resulting in a high temperature of the smoke in the low temperature area.

[0058] When the combustion surface is smaller than the heating surface of the water group tube 4, the small diameter light tube 402 can be set as a pipe with thin ends and thick middle, so that the gap between the upper and lower ends of the tube gradually increases, thereby achieving uniform flow of smoke.

[0059] Example 4: Reference Fig. 9 A modularly assembled large water-cooled premixed combustion boiler is basically the same as Example 1. Furthermore, when the combustion surface is smaller than the heating surface of the water group tube 4, a gradually increasing air gap 404 is provided between the small diameter light tubes 402 located on both sides of the combustion surface, and a baffle 406 is installed in the installation gap 405 to form a serpentine channel, which can improve the heat utilization rate of the flue gas.

[0060] Example 5: Reference Figure 2 , Figure 3 and Figure 6 A modularly assembled large water-cooled premixed combustion boiler is basically the same as Example 1. Furthermore, a first heat exchange tube 606 is arranged in the economizer module 6, a water inlet pipe 604 is arranged at one end of the first heat exchange tube 606, and a water outlet pipe 605 is arranged at the other end of the first heat exchange tube 606.

[0061] A water pump is provided at the water inlet pipe 604 to supply heated water to the water inlet 105 .

[0062] The superheater is arranged on the upper side of the economizer module 6 , and the first heat exchange tube 606 is arranged on the lower side of the economizer module 6 .

[0063] When the customer has a lower requirement for the temperature of the superheated steam, the superheater is installed in the economizer module 6, and the flue gas is transported to the smoke inlet 601 through the connecting pipe 603 and flows from top to bottom. The flue gas passing through the low temperature zone absorbs the heat of the high temperature steam in the second heat exchange tube 610, and then is discharged from the smoke exhaust port 602. Before the flue gas is discharged, it contacts the first heat exchange tube 606, exchanges the heat in the flue gas to the water in the first heat exchange tube 606, and preheats the water, thereby effectively utilizing the heat and reducing energy loss.

[0064] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A modularly assembled large water-cooled premixed combustion boiler, comprising: A boiler module, the boiler module comprising an upper cylinder (1), a lower cylinder (2), a water group pipe (4), a membrane wall group (5) and a furnace area (3), characterized in that it also comprises: an economizer module (6), the economizer module (6) being provided with a smoke inlet (601) and a smoke exhaust port (602); a smoke exhaust area (503) being provided on one side of the membrane wall group (5); a connecting pipe (603) being detachably connected between the smoke inlet (601) and the smoke exhaust area (503); a superheater, the superheater It comprises a second heat exchange tube (610), a hot gas inlet tube (607) and a hot gas outlet tube (608); when the required superheated steam temperature is greater than the steam temperature output by the upper cylinder (1), the furnace area (3) is made into a furnace module, and the superheater is arranged in the furnace of the furnace module; when the required superheated steam temperature is less than the steam temperature output by the upper cylinder (1), the superheater is arranged in the economizer module (6), and at this time, a return pipe (609) is arranged at the lower end of the second heat exchange tube (610).

2. A modularly assembled large water-cooled premixed combustion boiler according to claim 1, characterized in that: The upper cylinder (1) and the lower cylinder (2) are both arranged as semicircular cylinders. The upper cylinder (1) is provided with a liquid level gauge tube seat (106), an upper inspection port (101), a vent pipe (102), an exhaust pipe (103), a safety valve (104) and a water inlet (105) in sequence, and the lower cylinder (2) is provided with a lower inspection port (201), a sewage drain (202) and a sewage outlet (203).

3. A modularly assembled large water-cooled premixed combustion boiler according to claim 1, characterized in that: The membrane wall group (5) comprises a plurality of membrane wall tubes (501) arranged equidistantly between the upper cylinder (1) and the lower cylinder (2), and a steel plate (502) is provided between two adjacent membrane wall tubes (501).

4. A modularly assembled large water-cooled premixed combustion boiler according to claim 1, characterized in that: A combustion surface is provided on one side of the membrane wall group (5), the combustion surface matches the furnace area (3), a mixing chamber is provided in the furnace area (3), and an air-distributing orifice plate, a combustion surface tube group and a flame arrester are provided between the mixing chamber and the combustion surface.

5. A modularly assembled large water-cooled premixed combustion boiler according to claim 4, characterized in that: The water group tubes (4) comprise a plurality of groups of large-diameter light tubes (401), small-diameter light tubes (402), and spiral fin tubes (403) arranged in sequence, wherein the large-diameter light tubes (401) are arranged on a side close to the furnace area (3).

6. A modularly assembled large water-cooled premixed combustion boiler according to claim 5, characterized in that: An installation gap (405) is provided between two adjacent groups of spiral fin tubes (403), a baffle (406) is provided in the installation gap (405), and a plurality of baffles (406) form a serpentine air passage.

7. A modularly assembled large water-cooled premixed combustion boiler according to claim 6, characterized in that: The baffle (406) is configured to be in a wave shape that matches the spiral fin tube (403).

8. A modularly assembled large water-cooled premixed combustion boiler according to claim 7, characterized in that: The baffle (406) is provided with a plurality of pressure relief holes (407) arranged at equal distances.

9. A modularly assembled large water-cooled premixed combustion boiler according to claim 5 or 8, characterized in that: A gradually increasing air gap (404) is provided between the small-diameter light tubes (402) located on both sides of the combustion surface.

10. The modular assembly large water-cooled premixed combustion boiler according to claim 1, characterized in that: A first heat exchange tube (606) is provided in the economizer module (6); a water inlet pipe (604) is provided at one end of the first heat exchange tube (606); and a water outlet pipe (605) is provided at the other end of the first heat exchange tube (606).

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