A boiler with low nitrogen emissions

Abstract

The present invention discloses a novel energy-saving and low-nitrogen-emission boiler, which includes a boiler body, a flue gas convection heat exchanger, and a condensation heat exchanger; the bottom of the boiler has a support structure, and a smoke exhaust box is provided on one side of the support structure facing the condensation heat exchanger; the smoke exhaust box extends horizontally outwards with a smoke exhaust port; the surface of the boiler body is coated with a nano-composite coating; a burner assembly and a air supply assembly cooperating with the burner assembly are installed on the top of the boiler body. After the inner wall of the furnace of the boiler of the present invention is coated with the nano-composite coating, the heat absorption per unit area at high temperature can be increased by 1.5 to 2 times, the temperature of the furnace is greatly reduced, and it is not necessary to increase the volume of the furnace to reduce the NO X emission amount, and at the same time, the steel consumption can also be reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of burners, and in particular to a novel energy-saving and low-nitrogen-emission boiler that uses a new nano-composite heat transfer material and a new combustion technology burner to reduce consumables, save energy, and achieve low-nitrogen emissions. Background Art

[0002] With the continuous improvement of environmental protection requirements and the implementation of air rectification and boiler emission control, coal-fired boilers have been completely phased out and all have been improved to gas boilers. And in the flue gas emissions of all boilers, the NO X content is less than 80 mg / Nm 3 ; and with the treatment, it is gradually reduced to below 30 mg / Nm 3 . With the proposal of "carbon peak and carbon neutrality", energy conservation and emission reduction have been put on the daily agenda in various industries, especially in the iron and steel industry where capacity reduction is particularly prominent.

[0003] The existing technologies mainly have two methods. The first is the energy-saving method for gas boilers, which is to install a flue gas recovery condenser at the tail or the upper part of the boiler to absorb and preheat. The second is that when the flame combustion temperature is greater than 1200 °C, the NO X content rises sharply, and the core principle of nitrogen reduction is to reduce the temperature of the flame.

[0004] And the main technical means based on the above two methods are respectively:

[0005] The first one: Enlarge the boiler furnace, set an internal recirculation structure, and the FGR flue gas recirculation method;

[0006] The purpose of enlarging the furnace is to reduce the combustion temperature by reducing the heat load per unit area of the furnace. Internal recirculation is to return the low-temperature part around the flame to the middle of the flame for cooling. This method can only reduce the NO X content to below 80 mg / Nm 3 . Installing FGR flue gas recirculation is to draw back the waste gas from the chimney at the tail of the boiler and supply it to the center of the flame to reduce the temperature of the flame center. Only by combining the two can the flue gas emissions be reduced to below 30 mg / Nm 3 or less.

[0007] And this technology has some adverse problems. First of all, the boiler volume is enlarged, the floor area is large, resulting in a 15-20% increase in steel consumption and an increase in cost; the NO X emissions are unstable. It is not that the emissions meet the standards within the range of 10-100% load. In addition, the environmental protection test standard is that it is qualified under the 75% load state. The qualified one is just a point, and the emissions are exceeded under more loads; the FGR recirculation method reduces the boiler output, and the efficiency is also reduced by about 1.5%, which is not conducive to energy conservation.

[0008] The second one: Adopt the full-premix surface combustion method;

[0009] Full-premix surface combustion means that the gas and air are premixed in advance and then burned in the dense small holes on the surface of the metal mesh, which reduces NO emissions for surface combustion. This method can achieve NO emissions of about 20 mg / Nm³ without increasing the boiler volume. X emissions, and this method can achieve NO X emissions of 20 mg / Nm 3 or so.

[0010] However, this method also has some disadvantages, such as high maintenance costs, great potential safety hazards, the burner needs to be equipped with an air filter, which should be cleaned at least once a week according to the environment, and the burner head needs to be replaced at least once a heating period; at the same time, the burner head is prone to local burnout, resulting in furnace explosion accidents.

[0011] In summary, based on the technical problems existing in the above-mentioned prior art, those skilled in the art urgently need to develop a new type of boiler. Summary of the Invention

[0012] The purpose of the present invention is to provide a boiler with a compact and novel structure, a low-nitrogen combustion method, durability, no need for cumbersome maintenance, material saving, and low cost.

[0013] In order to achieve the above purpose, the present invention provides the following technical solutions:

[0014] A low-nitrogen emission boiler of the present invention, the boiler includes:

[0015] A boiler body;

[0016] A flue gas convection heat exchanger integrated at the lower part of the boiler body; and

[0017] A condensation heat exchanger integrated at the lower part of the flue gas convection heat exchanger;

[0018] The bottom of the boiler has a support structure, and a smoke exhaust box is provided on one side of the support structure facing the condensation heat exchanger;

[0019] The smoke exhaust box extends horizontally outwards with a smoke exhaust port;

[0020] The surface of the boiler body is coated with a nano-composite coating;

[0021] A burner assembly is installed on the top of the boiler body, and an air supply assembly is provided to cooperate with the burner assembly.

[0022] Further, the boiler body includes:

[0023] A furnace tube in a cylindrical structure;

[0024] A furnace chamber sleeved inside the furnace tube; and

[0025] The boiler head installed at the upper end of the furnace barrel;

[0026] The surfaces of the furnace are all coated with a nano-composite coating;

[0027] The burner assembly is installed on the boiler head, and the burner head of the burner assembly penetrates through the boiler head and extends into the interior of the furnace;

[0028] The burner head is located in the upper part of the furnace.

[0029] Further, the flue gas convection heat exchanger includes:

[0030] A radiation furnace diffusion structure connected to the boiler body, and a first heat exchange chamber is formed inside the radiation furnace diffusion structure;

[0031] Multiple radiation blocking tubes integrated inside the first heat exchange chamber; and

[0032] Multiple convection heat transfer tubes integrated inside the first heat exchange chamber;

[0033] The multiple radiation blocking tubes are arranged close to the boiler body, and the multiple radiation blocking tubes are arranged in parallel along the width direction of the first heat exchange chamber;

[0034] The multiple convection heat transfer tubes are arranged on the side of the radiation blocking tubes away from the boiler body, and the multiple convection heat transfer tubes are arranged in parallel.

[0035] Further, the radiation furnace diffusion structure has:

[0036] A top diffusion plate close to the boiler body and connected to the boiler body, and diffusion holes communicating with the furnace are evenly distributed on the top diffusion plate;

[0037] A first tube plate for supporting the radiation blocking tubes and the convection heat transfer tubes;

[0038] An inclined diffusion plate with one end connected to the first tube plate and the other end extending obliquely upward and connected to the top diffusion plate; and a side diffusion plate integrated on the side;

[0039] The bottom of the convection heat exchanger structure has a radiation furnace bottom frame connected to the condensation heat exchanger;

[0040] The side diffusion plate includes a first diffusion plate body and a second diffusion plate body;

[0041] The first diffusion plate body extends in the vertical direction and is arranged on the side of the flue gas convection heat exchanger, and the lower end of the first diffusion plate body is connected to the radiation furnace bottom frame;

[0042] The first diffusion plate body and the second diffusion plate body are of an integral structure;

[0043] The second diffusion plate body extends obliquely, and the second diffusion plate body covers and is connected to the inclined diffusion plate.

[0044] Furthermore, the condensation heat exchanger includes:

[0045] A second tube sheet connected to the bottom frame of the radiation furnace;

[0046] Multiple condenser heat exchange tubes, which are installed in the condensation heat exchanger through the second tube sheet, and a second heat exchange chamber is formed inside the condensation heat exchanger;

[0047] The condensation heat exchanger has a condenser water jacket header outside, and the condenser water jacket header is connected to an external water source through a boiler water inlet pipe to receive cold water supplied by the external water source;

[0048] The bottom of the condensation heat exchanger has a condensation heat exchanger bottom frame, and the condensation heat exchanger is assembled and fixed to the support structure through the condensation heat exchanger bottom frame;

[0049] The outer side of the condenser water jacket header of the condensation heat exchanger is closed by a condensate water jacket outer plate.

[0050] Furthermore, the support structure includes:

[0051] The smoke exhaust box; and a support supporting the bottom of the smoke exhaust box;

[0052] The support includes a support frame supported on the ground and legs extending towards the smoke exhaust box, and the smoke exhaust box is connected to the support frame through the legs;

[0053] The side of the smoke exhaust box that cooperates with the condensation heat exchanger has a smoke exhaust box frame, and the smoke exhaust box frame is assembled with the condensation heat exchanger bottom frame;

[0054] The inside of the smoke exhaust box is hollow to form a smoke exhaust chamber, and the smoke exhaust port is communicated with the smoke exhaust chamber to discharge the flue gas after heat exchange to the outside.

[0055] Furthermore, the burner assembly has:

[0056] The burner head; and a gas pipeline with one end connected to the burner head and the other end extending outwards and connected to an external gas gas source;

[0057] A valve group for controlling gas delivery is installed on the gas pipeline.

[0058] Further, the burner head is a cyclone burner head, and the combustion port of the burner head is circumferential, and the combustion flame extends downward along the inner wall of the furnace.

[0059] Further, the air supply assembly includes:

[0060] An air supply duct cooperating with the burner assembly; and

[0061] An air supply fan communicated with the air supply duct through an air supply elbow, and the air supply fan provides oxygen for the combustion of the burner assembly.

[0062] In the above technical solution, a boiler with low nitrogen emissions provided by the present invention has the following beneficial effects:

[0063] When the boiler body of the boiler of the present invention is coated with a nano-composite coating, the heat absorption per unit area at high temperature can be increased by 1.5 to 2 times, greatly reducing the temperature of the furnace. Without increasing the volume of the furnace, the steel consumption can be reduced, and at the same time, the NO X emission is reduced.

[0064] The boiler of the present invention burns with multiple flames through a cyclone burner head. By making the flames as close as possible to the inner wall of the furnace, the flames rotate and descend along the water-cooled wall in an annular structure, fully flushing the water-cooled wall, so that the flame temperature is reduced to below 1200 °C, and the NO X emission is maintained below 25 mg / Nm 3 under the load range of 10-100%.

[0065] In the boiler of the present invention, the heat absorption surface in the high-temperature radiation area of the boiler body absorbs 75-80% of the total load through the nano-composite coating, while the low-temperature convection area formed by the stainless steel tube group utilizes the advantage of the large heat absorption surface of the finned tubes to absorb 20-25% of the total load; this boiler reduces the volume of the boiler, saves about 60% of the floor area, saves about 55% of the steel consumption, provides stepless regulation of heat supply at full load and continuously has low nitrogen emissions, has a thermal efficiency of 98-105%, and has no risks such as combustion deflagration and explosion, and has higher safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings.

[0067] Figure 1 It is a schematic structural diagram of a boiler with low nitrogen emissions provided by an embodiment of the present invention;

[0068] Figure 2Schematic diagram of the flame of a burner head of a low-nitrogen emission boiler provided by an embodiment of the present invention.

[0069] Description of reference numerals:

[0070] 1. Boiler body; 2. Flue gas convection heat exchanger; 3. Condensing heat exchanger; 4. Support structure; 5. Burner assembly; 6. Air supply assembly;

[0071] 101. Drum; 102. Furnace; 103. Burner duct; 104. Boiler head; 105. Nano-composite coating;

[0072] 201. First tube sheet; 202. Radiation blocking tube; 203. Convection heat transfer tube; 204. Top diffusion plate; 205. Inclined diffusion plate; 206. First diffusion plate body; 207. Second diffusion plate body; 208. Radiation furnace bottom frame;

[0073] 301. Second tube sheet; 302. Condenser heat exchange tube; 303. Condenser water jacket header; 304. Condensing heat exchanger bottom frame; 305. Boiler water inlet pipe; 306. Condensing water jacket outer plate;

[0074] 401. Smoke exhaust box; 402. Smoke exhaust port; 403. Support frame; 404. Leg;

[0075] 501. Burner head; 502. Gas pipeline; 503. Valve group;

[0076] 601. Air supply pipeline; 602. Air supply elbow; 603. Air supply fan. Detailed implementation manners

[0077] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further introduced in detail below with reference to the accompanying drawings.

[0078] See Figures 1 to 2 as shown;

[0079] A low-nitrogen emission boiler of the present invention, the boiler includes:

[0080] Boiler body 1;

[0081] A flue gas convection heat exchanger 2 integrated at the lower part of the boiler body 1; and

[0082] A condensing heat exchanger 3 integrated at the lower part of the flue gas convection heat exchanger 2;

[0083] The bottom of the boiler has a support structure 4, and a smoke exhaust box 401 is provided on the side of the support structure 4 facing the condensing heat exchanger 3;

[0084] The smoke exhaust box 401 extends horizontally outwards with a smoke exhaust port 402;

[0085] The surface of the boiler body 1 is coated with a nano-composite coating 105;

[0086] A burner assembly 5 and an air supply assembly 6 cooperating with the burner assembly 5 are installed on the top of the boiler body 1.

[0087] Specifically, this embodiment discloses a novel boiler structure, which mainly includes a boiler body 1, a flue gas convection heat exchanger 2, a condensation heat exchanger 3, and a support structure 4 integrated at the bottom of the boiler. At the same time, a smoke exhaust box 401 is formed above the support structure 4, and the smoke exhaust box 401 has a smoke exhaust port 402 extending outward. In order to achieve the design requirements of low nitrogen emission and small volume of the boiler in this embodiment, a nano-composite coating 105 is coated on the surface of the boiler body 1 to increase the heat absorption per unit area through the nano-composite coating 105; the boiler disclosed in this embodiment is different from the boiler structures in the prior art in that the smoke exhaust port 402 is designed at the bottom of the boiler body 1, and the high-temperature flue gas generated by combustion passes through the high-temperature radiation area and the low-temperature convection area, reducing the flue gas temperature. The nano-composite coating 105 involved in this embodiment is formed by mixing borax, silica, zinc oxide, zirconia, titanium oxide, alumina, zirconia, and a binder in proportion and spraying them on the inner wall of the furnace and firing at high temperature.

[0088] Preferably, the boiler body 1 of this embodiment includes:

[0089] A furnace barrel 101 in a cylindrical structure;

[0090] A furnace chamber 102 sleeved inside the furnace barrel 101; and

[0091] A boiler head 104 installed at the upper end of the furnace barrel 101;

[0092] The surface of the furnace chamber 102 is coated with a nano-composite coating 105;

[0093] The burner assembly 5 is installed on the boiler head 104, and the burner head 501 of the burner assembly 5 penetrates through the boiler head 104 and extends into the furnace chamber 102;

[0094] The burner head 501 is located in the upper part of the furnace chamber 102.

[0095] The structure of the boiler body 1 is introduced in detail here. It includes a furnace barrel 101 and a furnace chamber 102 located inside the furnace barrel 101. The area between the furnace barrel 101 and the furnace chamber 102 can be used as a water jacket area, and cold water is filled between them for heat exchange with the flue gas. The furnace chamber 102 is treated with the nano-composite coating 105 to form a heat receiving surface in the high-temperature radiation area, and 75% - 80% of the total load is absorbed through the nano-composite coating 105.

[0096] Preferably, the flue gas convection heat exchanger 2 of this embodiment includes:

[0097] A radiation furnace diffusion structure connected to the boiler body 1, and a first heat exchange chamber is formed inside the radiation furnace diffusion structure;

[0098] Multiple radiation blocking tubes 202 integrated inside the first heat exchange chamber; and

[0099] Multiple convection heat transfer tubes 203 integrated inside the first heat exchange chamber;

[0100] The multiple radiation blocking tubes 202 are arranged close to the boiler body 1, and the multiple radiation blocking tubes 202 are arranged in parallel along the width direction of the first heat exchange chamber;

[0101] The multiple convection heat transfer tubes 203 are arranged on the side of the radiation blocking tubes 202 away from the boiler body 1, and the multiple convection heat transfer tubes 203 are arranged in parallel.

[0102] Among them, the above-mentioned radiation furnace diffusion structure has:

[0103] A top diffusion plate 204 close to the boiler body 1 and connected to the boiler body 1, and diffusion holes communicating with the furnace 102 are evenly distributed on the top diffusion plate 204;

[0104] A first tube sheet 201 for carrying the radiation blocking tubes 202 and the convection heat transfer tubes 203;

[0105] An inclined diffusion plate 205 with one end connected to the first tube sheet 201 and the other end extending obliquely upward and connected to the top diffusion plate 204; and

[0106] A side diffusion plate integrated on the side;

[0107] The bottom of the radiation furnace diffusion structure has a radiation furnace bottom frame 208 connected to the condensation heat exchanger 3;

[0108] The side diffusion plate includes a first diffusion plate body 206 and a second diffusion plate body 207;

[0109] The first diffusion plate body 206 extends in the vertical direction and is arranged on the side of the flue gas convection heat exchanger 2, and the lower end of the first diffusion plate body 206 is connected to the radiation furnace bottom frame 208;

[0110] The first diffusion plate body 206 and the second diffusion plate body 207 are of an integral structure;

[0111] The second diffusion plate body 207 extends obliquely, and the second diffusion plate body 207 covers and is connected to the inclined diffusion plate 205.

[0112] First, the structural composition of the flue gas convection heat exchanger 2 is defined. It integrates multiple radiation blocking tubes 202 and multiple convection heat transfer tubes 203 through the first tube sheets 201 on both sides, and forms the flue gas convection heat exchanger 2 by using the above-mentioned radiation furnace diffusion structure. The flue gas convection heat exchanger 2 disclosed in this embodiment serves as the first low-temperature convection zone for flue gas cooling.

[0113] Preferably, the condensation heat exchanger 3 of this embodiment includes:

[0114] A second tube sheet 301 connected to the bottom frame 304 of the radiation furnace;

[0115] Multiple condenser heat exchange tubes 302, and the condenser heat exchange tubes 302 are installed in the condensation heat exchanger 3 through the second tube sheet 301, and a second heat exchange chamber is formed inside the condensation heat exchanger 3;

[0116] The condensation heat exchanger 3 has a condenser water jacket header 303 outside. The condenser water jacket header 303 is connected to an external water source through a boiler water inlet pipe 305 to receive cold water supplied by the external water source;

[0117] The bottom of the condensation heat exchanger 3 has a condensation heat exchanger bottom frame 304, and the condensation heat exchanger 3 is fixedly assembled with the support structure 4 through the condensation heat exchanger bottom frame 304;

[0118] The outer side of the condenser water jacket header 303 of the condensation heat exchanger 3 is closed by a condensate water jacket outer plate 306.

[0119] The structural composition of the condensation heat exchanger 3 is introduced in detail here. It integrates multiple condenser heat exchange tubes 302 by using the above-mentioned second tube sheet 301, and the condensation heat exchanger 3 of this embodiment serves as the second low-temperature convection zone for flue gas cooling.

[0120] Through the cooling treatment of the flue gas by the above two low-temperature convection zones, the treated flue gas enters the smoke exhaust box 401 of the support structure 4 at the bottom of the boiler body 1 and is discharged through the smoke exhaust port 402.

[0121] More specifically, the above-mentioned support structure 4 includes:

[0122] A smoke exhaust box 401; and

[0123] A support supporting the bottom of the smoke exhaust box 401;

[0124] The support includes a support frame 403 supported on the ground and legs 404 extending towards the smoke exhaust box 401. The smoke exhaust box 401 is connected to the support frame 403 through the legs 404;

[0125] The side of the smoke exhaust box 401 cooperating with the condensation heat exchanger 3 has a smoke exhaust box frame, and the smoke exhaust box frame is assembled with the condensation heat exchanger bottom frame 304;

[0126] The inside of the smoke exhaust box 401 is hollow to form a smoke exhaust cavity, and the smoke exhaust port 402 is communicated with the smoke exhaust cavity to discharge the heat-exchanged flue gas to the outside.

[0127] Preferably, in this embodiment, the burner assembly 5 has:

[0128] A burner head 501; and

[0129] A gas pipeline 502 with one end connected to the burner head 501 and the other end extending outward and connected to an external gas source;

[0130] A valve group 503 for controlling gas delivery is installed on the gas pipeline 502.

[0131] Specifically, the burner head 501 of this embodiment is a cyclone burner head. The combustion port of the burner head 501 is circumferential, and the burning flame extends downward along the inner wall of the furnace chamber 102.

[0132] The air supply assembly 6 includes:

[0133] An air supply pipeline 601 cooperating with the burner assembly 5; and

[0134] An air supply fan 603 communicated with the air supply pipeline 601 through an air supply elbow 602. The air supply fan 603 provides oxygen for the combustion of the burner assembly 5.

[0135] In the above technical solution, a boiler with low nitrogen emissions provided by the present invention has the following beneficial effects:

[0136] When the boiler body of the boiler of the present invention is coated with the nano-composite coating 105, the heat absorption per unit area at high temperature can be increased by 1.5 to 2 times, greatly reducing the temperature of the furnace chamber 102. Without increasing the volume of the furnace chamber 102, the steel consumption can be reduced, and at the same time, the NO X emission is also reduced.

[0137] The boiler of the present invention burns with multiple flames through a cyclone burner head. By making the flames as close as possible to the inner wall of the furnace chamber 102, the flames rotate and descend along the water-cooled wall in an annular structure, fully flushing the water-cooled wall, so that the flame temperature is reduced below 1200 °C, and the NO X emission is maintained below 25 mg / Nm 3 in the range of 10-100% load.

[0138] In the boiler body 1 of the boiler of the present invention, the heating surface in the high-temperature radiation area absorbs 75-80% of the total load of heat through the nano-composite coating 105, while the low-temperature convection area formed by the stainless steel tube group utilizes the advantage of the large heat absorption surface of the finned tubes to absorb 20-25% of the total load of heat; this boiler reduces the volume of the boiler, saves about 60% of the floor area, saves about 55% of the steel consumption, provides stepless regulation of heat supply at full load and continuous low nitrogen emissions, has a thermal efficiency of 98-105%, has no risks such as combustion deflagration and explosion, and has higher safety.

[0139] Only some exemplary embodiments of the present invention have been described above by way of illustration. Without doubt, for those of ordinary skill in the art, various different ways can be used to modify the described embodiments without departing from the spirit and scope of the present invention. Therefore, the above drawings and description are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A boiler with low nitrogen emissions, characterized in that, the boiler comprises: a boiler body (1); a flue gas convection heat exchanger (2) integrated at the lower part of the boiler body (1); and a condensation heat exchanger (3) integrated at the lower part of the flue gas convection heat exchanger (2); the bottom of the boiler has a support structure (4), and a smoke exhaust box (401) is arranged on one side of the support structure (4) facing the condensation heat exchanger (3); the smoke exhaust box (401) extends horizontally outwards with a smoke exhaust port (402); the surface of the boiler body (1) is coated with a nano composite coating (105); a burner assembly (5) is installed at the top of the boiler body (1), and an air supply assembly (6) cooperating with the burner assembly (5); the boiler body (1) comprises: a furnace barrel (101) in a cylindrical structure; a furnace chamber (102) sleeved inside the furnace barrel (101); and a boiler head (104) installed at the upper end of the furnace barrel (101); the surface of the furnace chamber (102) is coated with a nano composite coating (105); the burner assembly (5) is installed on the boiler head (104), and the burner head (501) of the burner assembly (5) penetrates through the boiler head (104) and extends into the furnace chamber (102); the burner head (501) is located at the upper part of the furnace chamber (102); the burner assembly (5) has: the burner head (501); and a gas pipeline (502) with one end connected to the burner head (501) and the other end extending outwards and connected to an external gas gas source; a valve group (503) for controlling gas delivery is installed on the gas pipeline (502); the burner head (501) is a cyclone burner head, the combustion port of the burner head (501) is circumferential, and the burning flame extends downwards along the inner wall of the furnace chamber (102); the air supply assembly (6) comprises: an air supply pipeline (601) cooperating with the burner assembly (5); and an air supply fan (603) communicated with the air supply pipeline (601) through an air supply elbow (602), and the air supply fan (603) provides oxygen for the combustion of the burner assembly (5).

2. The boiler with low nitrogen emissions according to claim 1, characterized in that, the flue gas convection heat exchanger (2) comprises: a radiation furnace chamber diffusion structure connected to the boiler body (1), and a first heat exchange chamber is formed inside the radiation furnace chamber diffusion structure; multiple radiation blocking pipes (202) integrated inside the first heat exchange chamber; and multiple convection heat transfer pipes (203) integrated inside the first heat exchange chamber; multiple radiation blocking pipes (202) are arranged close to the furnace chamber of the boiler body (1), and multiple radiation blocking pipes (202) are arranged in parallel along the width direction of the first heat exchange chamber; multiple convection heat transfer pipes (203) are arranged on the side of the radiation blocking pipes (202) away from the boiler body (1), and multiple convection heat transfer pipes (203) are arranged in parallel.

3. The boiler with low nitrogen emissions according to claim 2, It is characterized in that the radiation furnace diffusion structure has: a top diffusion plate (204) close to and connected to the boiler body (1), and the top diffusion plate (204) is evenly distributed with diffusion holes communicating with the furnace (102); a first tube sheet (201) for carrying the radiation blocking tube (202) and the convection heat transfer tube (203); an inclined diffusion plate (205) with one end connected to the first tube sheet (201) and the other end extending obliquely upward and connected to the top diffusion plate (204); and a side diffusion plate integrated on the side; the bottom of the radiation furnace diffusion structure has a radiation furnace bottom frame (208) connected to the condensation heat exchanger (3); the side diffusion plate includes a first diffusion plate body (206) and a second diffusion plate body (207); the first diffusion plate body (206) extends in the vertical direction and is arranged on the side of the flue gas convection heat exchanger (2), and the lower end of the first diffusion plate body (206) is connected to the radiation furnace bottom frame (208); the first diffusion plate body (206) and the second diffusion plate body (207) are of an integral structure; the second diffusion plate body (207) extends obliquely, and the second diffusion plate body (207) covers and is connected to the inclined diffusion plate (205).

4. A low-nitrogen emission boiler according to claim 3, It is characterized in that the condensation heat exchanger (3) includes: a second tube sheet (301) connected to the radiation furnace bottom frame (208); a plurality of condenser heat exchange tubes (302), and the condenser heat exchange tubes (302) are installed in the condensation heat exchanger (3) through the second tube sheet (301), and a second heat exchange cavity is formed inside the condensation heat exchanger (3); the condensation heat exchanger (3) has a condenser water jacket header (303) outside, and the condenser water jacket header (303) is connected to an external water source through a boiler water inlet pipe (305) to receive cold water supplied by the external water source; the bottom of the condensation heat exchanger (3) has a condensation heat exchanger bottom frame (304), and the condensation heat exchanger (3) is assembled and fixed to the support structure (4) through the condensation heat exchanger bottom frame (304); the outer side of the condenser water jacket header (303) of the condensation heat exchanger (3) is closed by a condensation water jacket outer plate (306).

5. A low-nitrogen emission boiler according to claim 4, It is characterized in that the support structure (4) includes: the smoke exhaust box (401); and a support supporting the bottom of the smoke exhaust box (401); the support includes a support frame (403) supported on the ground and a leg (404) extending towards the smoke exhaust box (401), and the smoke exhaust box (401) is connected to the support frame (403) through the leg (404); the side of the smoke exhaust box (401) cooperating with the condensation heat exchanger (3) has a smoke exhaust box frame, and the smoke exhaust box frame is assembled with the condensation heat exchanger bottom frame (304). The interior of the smoke exhaust box (401) is hollow to form a smoke exhaust cavity, and the smoke exhaust port (402) communicates with the smoke exhaust cavity to discharge the heat-exchanged flue gas to the outside.

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