A vertical water pipe built-in premixed membrane wall cooling burner and gas boiler

Abstract

The present invention discloses a vertical water pipe built-in premixed membrane wall cooling burner and a gas boiler, the gas boiler includes a burner, a furnace, a heat exchanger and a flue; the burner adopts a combustion mode of built-in premixer and membrane wall cooling, with a central side-by-side tube bundle or an arc side tube bundle as the burner head, the furnace is two semi-cylindrical spaces surrounded by the burner and the heat exchanger, the heat exchanger is a water pipe bundle connected to the upper and lower annular headers and expanded along 1 to 3 circles of circular arcs; the burner and the heat exchanger can be swapped; after the premixed gas is burned by the burner, the flue gas generated flushes the relative heat exchange area and is collected and discharged by the flue. The present invention has a compact structure, low resistance and high heat exchange efficiency; the gas flow is short, the mixing and distribution are uniform, explosion-proof, and the safety is high, and it is suitable for the blending of natural gas and low / zero carbon fuels and the combustion of pure fuels; the combustion temperature is low, the load is uniform, the adjustment ratio is large, and the NOx emission is low; the burner and the heat exchanger are connected to the header by an integral or partially detachable flange, and the maintainability is high.

Description

Technical Field

[0001] The present invention belongs to the field of high-efficiency, energy-saving and environmentally friendly compact burners, heat exchangers and boiler designs, and specifically relates to a vertical water tube built-in premixed membrane wall-cooled burner and a gas boiler. Background Art

[0002] As environmental protection standards become more stringent, low-nitrogen combustion and efficient heat exchange have become the key technologies for the development of gas boilers. At the same time, compactly designed gas boilers are the preferred choice of users. Vertical gas boilers have become the most widely used industrial boilers due to their small footprint, low steel consumption, fast steam production, and high degree of automation.

[0003] However, many vertical gas boilers currently have high nitrogen oxide emissions, and it is difficult to transform them into low-nitrogen combustion. Premixed water-cooled combustion is a new type of combustion method. After the gas and the air required for combustion are completely mixed, they are sprayed out from the gaps of the water-cooled tube bundle for combustion. The setting of the water-cooled tube bundle cools the root of the flame, and the nitrogen oxide emissions of the boiler are significantly reduced. Water-cooled combustion has become a key technology for solving nitrogen oxide emissions from industrial gas boilers. The current premixed water-cooled burner head is usually composed of a cylindrical water-cooled tube bundle or a single-plane water-cooled tube bundle. The flame area is small, the burner heat load is small, the boiler power is low, and the adjustment ratio during operation is low. In addition, traditional water-cooled low-nitrogen burners are prone to carbon deposition at low loads, and long-term operation can easily lead to the scrapping of the tube bundle.

[0004] Anhui Borite Company disclosed a cylindrical low-nitrogen energy-saving pressure water tube boiler structure in patent CN 212841492.U, which uses a single-plane water-cooled tube bundle as a burner, and uses membrane water-cooled tubes to surround a trapezoidal furnace. At the same time, the burner distribution head is made into a detachable drawer type, which is convenient for disassembly and cleaning of the burner while achieving low-nitrogen combustion. However, the burner of this structure has a low heat load and a low adjustment ratio. Zhejiang Liju Company disclosed three premixed water-cooled gas boiler structures using multiple combustion surfaces or multiple premixers or multiple distributors in patents CN 110425531.A, CN 107990552.A, and CN108036509.A, which solve the problems of low heat load and low adjustment ratio of the burner of the vertical premixed water-cooled gas boiler, but it occupies a large area, has poor compactness, and is complex in structure, high in cost, and poor in maintainability.

[0005] In addition, the current premixer is set at the front end of the burner, and the premixed gas is evenly flowed after mixing the gas and air. The gas flow is long, the gas and air are unevenly mixed, the flow resistance is large, and the flow field uniformity is poor. When the boiler is ignited and burned, it is easy to explode, affecting the safe operation of the boiler. Moreover, the current water-cooled tube bundles at the burner head are mostly arranged in two circles of light tubes in a staggered manner. The flame ejected from the gap of the water-cooled tube bundles at the burner head is not rigid enough, resulting in poor flame stability, making it difficult to form a stable flame surface, and difficult to ignite and operate stably at low load. Summary of the invention

[0006] In order to solve the above-mentioned problems existing in the vertical gas boiler, the present invention improves the traditional burner, embeds the gas nozzle behind the burner, combines the gas premixing process and the flow equalization process in the burner into one, proposes a novel built-in premixing water-cooled burner, improves the structure of the vertical gas boiler, adopts a premixing water-cooling combustion method, arranges an axisymmetric or center-symmetrical detachable double-plane premixing water-cooled burner in the middle of the cylindrical furnace, or directly utilizes the semi-cylindrical furnace heating surface tube bundle on one side or both sides as a part of the water-cooled burner, increases the heat load and regulation ratio of the burner, and the boiler has low nitrogen oxide emissions, high heat exchange efficiency, compact structure and good maintainability.

[0007] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a vertical water tube built-in premixed membrane wall-cooled burner, including a first distribution chamber, a second distribution chamber and a water-cooled tube bundle, the first distribution chamber is provided with an air inlet, a gas distribution pipe is provided in the first distribution chamber, and the gas distribution pipe has a gas inlet; the first distribution chamber is connected to the second distribution chamber; the second distribution chamber includes a partition and a distribution orifice plate, one end of the partition is connected to the first distribution chamber, and the other end is connected to the distribution orifice plate; the vertical area surrounded by the partition and the distribution orifice plate is the second distribution chamber, the distribution orifice plate is opposite to the water-cooled tube bundle, the water-cooled tube bundle is a membrane wall tube bundle, the membrane wall tube bundle is provided with air flow holes, and the membrane wall surface is a plane, an arc surface or a bent surface.

[0008] Furthermore, a first flow balancing orifice plate and a plurality of spoiler columns are arranged in the first distribution chamber, a second flow balancing orifice plate is arranged between the first distribution chamber and the second distribution chamber, the gas distribution pipe is arranged between the first flow balancing orifice plate and the second flow balancing orifice plate, the spoiler columns are arranged in front of and behind the first flow balancing orifice plate, the spoiler columns are arranged along the length direction of the gas distribution pipe, both ends of the spoiler columns are connected to the first distribution chamber, the cross-section of the spoiler column is triangular, V-shaped, square or circular, and in the case of a V-shaped cross-section, the bending angle of the V is toward the direction of the incoming air, and 3-50 spoiler columns are arranged.

[0009] Furthermore, the gas distribution pipe comprises a first gas distribution pipe, a second gas distribution pipe, a first gas spray hole, a second gas spray hole and a spoiler; a gas inlet is provided at one end or both ends of the first gas distribution pipe, the first gas distribution pipe is connected to the second gas distribution pipe, the first gas spray holes are evenly provided on the gas outlet surface of the first gas distribution pipe, and the second gas spray holes are evenly provided on the side surface of the second gas distribution pipe; the first gas spray holes are arranged in 1 to 8 rows, the second gas spray holes are arranged in 1 to 4 rows, the first gas spray holes are arranged in series or staggered rows, and the second gas spray holes are arranged in series or staggered rows; spoilers are welded on the top and bottom of the interface between the first gas distribution pipe and the second gas distribution pipe.

[0010] Furthermore, the flow area in the first gas distribution pipe along the gas intake direction remains unchanged or gradually decreases, and the flow area in the second distribution chamber along the mixed gas flow direction remains unchanged or gradually decreases.

[0011] Furthermore, the first gas distribution pipe is horizontally placed above the first distribution chamber, and one end of 3 to 20 evenly arranged second gas distribution pipes is vertically connected to the first gas distribution pipe, and the other end extends into the first distribution chamber; the gas inlet is located at one end, both ends and / or the middle of the first gas distribution pipe, 1 to 3 gas inlets are opened, and the second gas distribution pipe is provided with evenly arranged second gas nozzles along the air flow direction or away from the air flow direction or in both directions.

[0012] Furthermore, the mixture of gas and air in the burner is fed in perpendicularly to the distribution orifice plate or parallel to the distribution orifice plate, and the distribution orifice plate is arranged in 1 to 3 layers; a third equalizing flow orifice plate is arranged at the tail of the first distribution chamber, and a turning guide plate is arranged when the air is fed in parallel to the distribution orifice plate, and the turning guide plate is located at the junction of the first distribution chamber and the second distribution chamber, and the turning guide plate is connected to the third equalizing flow orifice plate; the two sides of the turning guide plate are connected to the two sides of the first distribution chamber and the second distribution chamber, and the cross-section is a right-angle "U" shape, a smoothly transitioned "U" shape, a "V" shape, an "L" shape or an "I" shape; when the turning guide plate is in an "I" shape, the turning guide plate is fixedly connected or hinged to the third equalizing flow orifice plate.

[0013] Furthermore, when the mixture intakes parallel to the distribution orifice plate, 1 to 10 vertical baffles parallel to the flow direction of the mixture are evenly arranged in the second distribution chamber along a direction perpendicular to the flow direction of the mixture, the front edge of the vertical baffle is connected to the top of the second distribution chamber, the rear edge of the vertical baffle is connected to the distribution orifice plate or is spaced 5 to 20 mm from the distribution orifice plate, and the top and bottom ends of the vertical baffle are respectively connected to the top and bottom surfaces of the second distribution chamber.

[0014] Furthermore, the membrane wall tube bundle includes a plurality of light tubes, two adjacent light tubes are welded by flat steel, the length direction of the flat steel is parallel to the light tube row, the flat steel is located on the center line of the light tube row or deviates from the center line of the light tube row, and the flat steel is correspondingly welded to the light tube on both sides or on one side; the thickness of the flat steel is 3 to 20 mm, and the welding depth of the arc surface of the flat steel in contact with the light tube in the thickness direction is at least 3 mm, and the flat steel is provided with regular premixed gas spray holes from bottom to top, i.e., gas flow holes, and the premixed gas spray holes are arranged on the flat steel. The center line of the hole is perpendicular or inclined to the flat steel plane, the premixed gas spray holes are in single row, double row or triple row, when there are more than one row of premixed gas spray holes, the two adjacent rows of premixed gas spray holes are arranged in sequence or staggered, and the premixed gas spray holes are circular, oblong, triangular or rectangular; the long axis of the oblong premixed gas spray hole is parallel or perpendicular to the longitudinal center line of the pipe; the vertex angle of the triangular premixed gas spray hole is 360° rotating angle, and it can be placed upright, inverted or tilted, and the long side of the rectangular premixed gas spray hole is parallel or perpendicular to the longitudinal center line of the pipe.

[0015] Furthermore, the water-cooled tube bundle includes at least two rows of smooth tubes, the flat steel is welded to the first row of smooth tubes, the flat steel is located between the second row of smooth tubes, a narrow gap is formed between the flat steel and the second row of smooth tubes, and evenly arranged flat steel fins or pads are welded on the flat steel; the flat steel fins are arc or rectangular surfaces, the pad cross-section is square, circular or oblong, the pad is welded to the second row of smooth tubes, and evenly arranged air flow holes are formed between the smooth tubes, the pad and the flat steel; an adjustable spray hole baffle is provided on the flat steel to block the premixed gas spray hole or the air flow hole formed by the pad, a premixed gas spray hole with the same size and position as the air flow hole is provided on the adjustable spray hole baffle, and the adjustable spray hole baffle slides along the axial direction of the membrane wall tube, and the sliding range can cover the premixed gas spray hole.

[0016] Furthermore, the membrane wall tube bundle includes multiple smooth tubes, and channel steels, I-beams, arc steels, angle steels, small round tubes or semi-circular tubes are welded between the smooth tubes. When arc steels are welded between the smooth tubes, the curvature α of the arc steel is: 0<α<π, and when angle steels are welded between the smooth tubes, the angle β of the angle steel is: 0<β<180°.

[0017] Furthermore, the membrane wall tube bundle is a combination of fin tubes and smooth tubes, the fin tubes are bent at opposite sides, the smooth tubes face the furnace or face away from the furnace, and the fin tubes are spiral fin tubes, circular fin tubes, square fin tubes or H-shaped fin tubes.

[0018] At the same time, the present invention provides a vertical water tube built-in premixed membrane wall-cooled combustion gas boiler, including a burner, a heat exchanger, a flue, an economizer, a condenser and a chimney; the burner and the heat exchanger surround two axially symmetrical semi-cylindrical furnaces, and two heating surfaces, a plane heat exchange section and an arc heat exchange section, are arranged in the furnace; the burner is arranged on the chord side of the semi-cylindrical furnace, and the heat exchanger is arranged on the arc side of the semi-cylindrical furnace, or the burner is arranged on the arc side of the semi-cylindrical furnace, and the heat exchanger is arranged on the chord side of the semi-cylindrical furnace, or the burner and the heat exchanger are respectively arranged on the arc sides of two semi-cylindrical furnaces; the burner adopts A premixed water-cooled burner uses a tube bundle of a flat heat exchange section or an arc-shaped heat exchange section as the water-cooled tube bundle of the burner; when the burner is located on the chord side of the semi-cylindrical furnace, the flue gases of the two semi-cylindrical furnaces flow to the outside of the cylinder respectively; when the burner is located on the arc side of the semi-cylindrical furnace, the two semi-cylindrical furnaces are connected, and the flue gases flow into the cylinder or flow in from one side of the cylinder and out from the other side; the burner, heat exchanger, flue, economizer, condenser and chimney are connected along the direction of the flue gas flow; the burner adopts the vertical water tube built-in premixed membrane wall-cooled burner described in any one of claims 1-12.

[0019] Furthermore, the planar heat exchange section includes a tubular upper header, a side-by-side heat exchange tube bundle and a tubular lower header; the two ends of the side-by-side heat exchange tube bundle are respectively connected to the tubular upper header and the tubular lower header; the arcuate heat exchange section includes an annular upper header, an inner ring heat exchange tube bundle, an outer ring heat exchange tube bundle and an annular lower header, the outer ring heat exchange tube bundle and the inner ring heat exchange tube bundle are arranged along the semi-cylindrical surface, and the two ends of the outer ring heat exchange tube bundle and the inner ring heat exchange tube bundle are connected to the annular upper header and the annular lower header; the outer ring heat exchange tube bundle and the inner ring heat exchange tube bundle are staggered; the bottom end of the annular upper header and the top end of the annular lower header are respectively sealed and connected to the furnace upper bottom plate and the furnace lower bottom plate; an outer shell baffle is arranged on the outside of the two semi-cylindrical furnaces.

[0020] Furthermore, when the maximum distance between the tubular upper header and the tubular lower header is less than the distance between the bottom of the annular upper header and the top of the annular lower header, the burner is detachable as a whole, and the tubular upper header and the tubular lower header are respectively provided with a tubular header steam outlet and a tubular header water inlet at both ends of the axial direction, and the tubular header steam outlet and the tubular header water inlet are connected to the connecting pipe through a flange, and the connecting pipe is a 180° elbow, one end of which is tightly connected to the flange on the tubular upper header or the tubular lower header, and the other end is connected to the outer side of the annular upper header or the annular lower header; the distance between the tubular upper header and the tubular lower header is When the farthest distance is greater than the distance between the bottom of the annular upper header and the top of the annular lower header, the burner is partially detachable, and the remaining burner parts except the tubular upper header, the side-by-side heat exchange tube bundle and the tubular lower header can be pulled out in the horizontal direction; the two ends of the axis of the tubular upper header and the tubular lower header are respectively connected to the annular upper header and the annular lower header, and the connection parts are the inner side surface or top of the annular upper header and the inner side surface or bottom of the annular lower header; the detachable part of the burner is connected and sealed with the annular upper header, the annular lower header, the furnace upper bottom plate, the furnace lower bottom plate and the outer shell baffle by using a drawer structure.

[0021] Furthermore, when the burner is arranged on the chord side of the semi-cylindrical furnace, a planar heat exchange section tube bundle is used as a water-cooling tube bundle of the burner, and the flue is arranged on the outside of the curved surfaces of the two semi-cylindrical furnaces; when the burner is arranged on the curved side of the semi-cylindrical furnace, the outer ring heat exchange tube bundle and the inner ring heat exchange tube bundle arranged along the semi-cylindrical surface are used as the water-cooling tube bundle of the burner, and the flue is arranged on the side between the two semi-cylindrical furnaces or on the outside of another curved surface of the semi-cylindrical furnace.

[0022] Furthermore, a downcomer is arranged on the periphery of the heating surface of the heat exchanger, and both ends of the downcomer are connected to an annular upper header and an annular lower header to form a natural circulation steam boiler.

[0023] Furthermore, a radiation heating tube bundle is arranged in the semi-cylindrical furnace. The radiation heating tube bundle is concave inwardly around and is divided into three sections: an upper inclined section, a middle vertical section and a lower inclined section. The three sections of a radiation heating tube are located in the same plane, and the upper inclined section and the lower inclined section face the same direction. The top of the radiation heating tube bundle is connected to the inner side or the top of the annular upper header, and the bottom of the radiation heating tube bundle is connected to the inner side or the bottom of the annular lower header. The radiation heating tube bundle is evenly arranged in the circumferential direction, and the 2-5 radiation heating tube bundles on both sides of the burner reduce the length of the upper inclined section and the lower inclined section.

[0024] Furthermore, the vertical cross-sections of the annular upper header and the annular lower header are rectangular, circular or elliptical with chamfers or rounded arcs on all sides. 2 to 3 circles of vertical heat exchange tube bundles are arranged between the annular upper header and the annular lower header. The inner circle heat exchange tube bundle close to the furnace is a plain tube, a spiral fin tube or a finned tube. When the inner circle heat exchange tube bundle is a spiral fin tube, the fin height is less than 10 mm, and when the inner circle heat exchange tube bundle is a finned tube, the fin height is less than 10 mm; the outer circle heat exchange tube bundle is an enhanced heat exchange tube bundle with a spiral fin tube, a fin tube or a special-shaped tube structure, and the height of the fin or fin is 30 to 100 mm; an annular header water inlet is arranged below the steam-water demarcation line or at the bottom of the side of the annular upper header, and an annular header steam outlet is arranged above the steam-water demarcation line or at the top of the side of the annular upper header; a sewage outlet is arranged on the side or bottom of the annular lower header.

[0025] Furthermore, 1 to 3 circles of tube bundles are arranged at the arc-shaped heat exchange section, and the cross-section formed by the tube bundles of the arc-shaped heat exchange section is arc-shaped, trapezoidal or "V"-shaped, and 1 to 2 rows of smooth tubes, spiral finned tubes, special-shaped tubes and / or gap guide plates are arranged at the side-by-side heat exchange tube bundles; a gap guide plate is arranged between two adjacent heat exchange tubes of the outer circle heat exchange tube bundle, and the gap guide plate is located on the inner side of the outer circle heat exchange tube bundle; or a gap guide plate is arranged between two adjacent heat exchange tubes of the inner circle heat exchange tube bundle, and the gap guide plate is located on the outer side of the inner circle heat exchange tube bundle; or gap guide plates are arranged in both the outer circle heat exchange tube bundle and the inner circle heat exchange tube bundle; an enhanced heat exchange channel is formed between the gap guide plate and the outer wall of the heat exchange tube.

[0026] Furthermore, the two heat exchange tubes at both ends of the inner ring heat exchange tube bundle and the outer ring heat exchange tube bundle are both configured as bare tubes, and a sealing tube is arranged between the bare tube and the tube bundles at both ends of the side-by-side heat exchange tube bundles. The sealing tube is a bare tube, and the sealing tube is tangent to the tube bundles at both ends of the side-by-side heat exchange tube bundles. The two ends of the sealing tube are respectively connected to the annular upper header and the annular lower header, and a bending structure is arranged at both ends of the sealing tube. A sealing plate is arranged to seal the longitudinal gap of the two bare tubes at the same end of the inner ring heat exchange tube bundle and the outer ring heat exchange tube bundle, the sealing tube and the burner at one end or both ends of the side-by-side heat exchange tube bundle when the burner is located on the arc side of the semi-cylindrical furnace.

[0027] Furthermore, the first flow balancing orifice plate, the second flow balancing orifice plate, the third flow balancing orifice plate, the distribution orifice plate, the sealing plate, the upper bottom plate of the furnace, the lower bottom plate of the furnace and the outer shell baffle are all made of high temperature resistant and deformation resistant materials, and the surfaces of the side-by-side heat exchange tube bundles, the inner ring heat exchange tube bundles and the radiation heating tube bundles that are in direct contact with the high-temperature flue gas are sprayed with nickel-chromium alloy; the burner is a natural gas burner, a natural gas blended low / zero carbon fuel burner or a pure low / zero carbon fuel burner, and the working medium of the heat exchanger is water or heat transfer oil.

[0028] Furthermore, when the burner is arranged on the side of the semi-cylindrical furnace chord, a double-sided burner or two single-sided burners are arranged with a side-by-side heat exchange tube bundle as a water-cooled tube bundle, and the burner flow area gradually decreases from the burner inlet to the burner end; when a double-sided burner is arranged, the burner takes in air on one side along the direction of the semi-cylindrical furnace chord, and exhausts air on both sides perpendicular to the air intake direction, and the burner is symmetrical along the axis perpendicular to the air intake direction; when two single-sided burners are arranged, the burner takes in air on both sides or one side along the direction of the semi-cylindrical furnace chord, and exhausts air on both sides perpendicular to the air intake direction, and the burner is centrally symmetrical or axially symmetrical.

[0029] Furthermore, when the burner is arranged on the arc side of the semi-cylindrical furnace, one or two single-sided burners are arranged with the outer ring heat exchange tube bundle and the inner ring heat exchange tube bundle as water-cooled tube bundles, the front end of the burner cross-section is square, the rear end is crescent-shaped, and the distribution orifice plate is arc-shaped; the diameter of the outer ring heat exchange tube bundle is larger than the diameter of the inner ring heat exchange tube bundle, the gap formed between adjacent tubes of the outer ring heat exchange tube bundle is 2-5mm, and the gap formed between adjacent tubes of the inner ring heat exchange tube bundle is 4-10mm; the number of columns of the outer ring heat exchange tube bundle is the same as the number of columns of the spray holes on the distribution orifice plate or the number of columns of the spray holes on the distribution orifice plate is an integer multiple of the number of columns of the outer ring heat exchange tube bundle, and the outer ring heat exchange tube bundle is directly opposite to the spray holes on the distribution orifice plate.

[0030] Furthermore, the flue includes a flue gas header, a flue gas duct and a flue outlet. When the burner is arranged on the chord side of the semi-cylindrical furnace, it is a double flue. The two flue gas headers are connected via the flue gas duct, and the flue gas in the two flue gas headers is collected through the flue gas duct and discharged from the flue outlet; when the burner is arranged on the arc side of the semi-cylindrical furnace, it is a single flue, and the smoke in the flue gas header is directly discharged from the flue outlet; the flue outlet is connected to the economizer, condenser and chimney in sequence; the fan outlet is connected to the burner, and the narrow surface of the fan is parallel to the corresponding connecting surface of the burner.

[0031] Furthermore, each combustion surface is arranged with one or two ignition needles, which can be extended into the furnace from the side, top or bottom of the furnace, and the ignition needles correspondingly pass through the sealing plate or the upper bottom plate of the furnace or the lower bottom plate of the furnace and extend into the furnace, and the ignition needles are 10-50mm away from the outer wall of the side-by-side heat exchange tube bundle or the outer wall of the inner circle heat exchange tube bundle.

[0032] Compared with the prior art, the present invention has at least the following beneficial effects:

[0033] The present invention places the gas nozzle behind the burner, combines the gas premixing process and the flow equalization process in the burner into one, and proposes a novel built-in premixing water-cooled burner with a reduced gas flow, uniform mixing and distribution, and low flow resistance. The burner is suitable for the combustion of low-carbon / zero-carbon fuels or pure low-carbon / zero-carbon fuels, thereby ensuring the safety of combustion. The present invention adopts a membrane wall tube bundle or a combination of a fin tube and a light tube as a burner water-cooling tube bundle to rectify the incoming premixed gas, thereby improving the flame stiffness, facilitating ignition and stable combustion, and not prone to backfire and flameout. At the same time, the flame length is short, the furnace space is small, and pollutant emissions are low.

[0034] Based on the present invention, a premixed water-cooled burner is provided, which can be arranged as a relative combustion surface, thereby increasing the flame area while reducing nitrogen oxide emissions, and increasing the heat load of the burner. An axially symmetrical or centrally symmetrical double-plane premixed water-cooled burner is arranged in the middle of the cylindrical furnace, or one or two semi-cylindrical furnace heating surface tube bundles are directly used as part of the water-cooled burner, and half of the burners can be opened separately for combustion at the same time, thereby increasing the regulation ratio. The present invention adopts two semi-circular columnar spaces as the furnace, and the burner, heat exchanger, and flue are all symmetrical structures, with uniform combustion, low resistance, and strong adaptability to boilers. It can be used as a modification plan for other industrial boilers, and the burner water-cooled tube bundle and the heat exchanger tube bundle are arranged to increase the heating surface, improve the heat exchange efficiency, and make the structure more compact.

[0035] Furthermore, the burner of the present invention is designed as a detachable drawer type, which is convenient for disassembly and cleaning of the burner. The space left after the burner is disassembled is convenient for repairing and cleaning the inside of the furnace, and the maintainability of the boiler is greatly improved.

[0036] Furthermore, the burner spray hole size of the present invention is adjustable, and a wide range of load adjustment can be achieved by only moving the adjustable spray hole baffle a very small distance, and the load adaptability is strong.

[0037] Furthermore, the present invention adds a radiation heating tube bundle on the basis of the burner water-cooling tube bundle and the heat exchanger tube bundle in the furnace, further improving the compactness of the structure, and adopts spiral fin tubes, guide plates, narrow gaps and other methods to enhance heat exchange, with high heat exchange efficiency and low flow resistance.

[0038] Furthermore, the present invention increases the operating life and safety of the boiler by providing refractory materials and performing a nickel-chromium alloy spraying treatment on the surface of the tube bundle that is in direct contact with the high-temperature flue gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1a This is a schematic cross-sectional view of a boiler according to scheme 1 of the present invention.

[0040] Figure 1b This is a schematic cross-sectional view of the boiler of Scheme 2 of the present invention.

[0041] Figure 1c This is a schematic cross-sectional view of a boiler according to scheme 3 of the present invention.

[0042] Figure 1d This is a schematic cross-sectional view of a boiler according to scheme 4 of the present invention.

[0043] Figure 1e This is a schematic cross-sectional view of a boiler according to scheme five of the present invention.

[0044] Figure 2a This is a schematic front sectional view of a boiler according to scheme 1 of the present invention.

[0045] Figure 2b This is a schematic right sectional view of the boiler according to Scheme 2 of the present invention.

[0046] Figure 2c This is a schematic front sectional view of a boiler according to scheme 3 of the present invention.

[0047] Figure 2d This is a schematic right sectional view of a boiler according to scheme 4 of the present invention.

[0048] Figure 2e This is a schematic right sectional view of a boiler according to scheme five of the present invention.

[0049] Figure 3a This is a schematic front cross-sectional view of the burner of Scheme 2 of the present invention.

[0050] Figure 3b This is a schematic cross-sectional view of the burner of Scheme 2 of the present invention.

[0051] Figure 3c It is a schematic cross-sectional view of a burner form according to the present invention.

[0052] Figure 3d This is a schematic cross-sectional view of burner type 2 of scheme 1 of the present invention.

[0053] Figure 4a This is a schematic diagram of the axial section of the burner of Scheme 3 and Scheme 4 of the present invention.

[0054] Figure 4b It is a front cross-sectional schematic diagram of the burner of Scheme 3 and Scheme 4 of the present invention.

[0055] Figure 4c This is a schematic cross-sectional view of the burner of Scheme 3 and Scheme 4 of the present invention.

[0056] Figure 5a This is a schematic cross-sectional view of the burner of scheme five of the present invention.

[0057] Figure 5b This is a schematic left sectional view of a burner according to scheme five of the present invention.

[0058] Figure 5c This is a schematic front sectional view of the burner of scheme 5 of the present invention.

[0059] Figure 6a This is a schematic diagram of a partial left-side cross-section of the turn of the burner of Scheme 5 of the present invention.

[0060] Figure 6b This is a partial left-side sectional view of a distribution chamber of a burner type 1 according to scheme 5 of the present invention.

[0061] Figure 6c This is a partial front sectional schematic diagram of a distribution chamber of the burner form one of scheme five of the present invention.

[0062] Figure 6d This is a partial cross-sectional schematic diagram of the distribution chamber of the second burner form of scheme five of the present invention.

[0063] Figure 6e This is a partial upper cross-sectional schematic diagram of the distribution chamber of the second burner type of scheme five of the present invention.

[0064] Figure 7a It is a schematic diagram of the circular hole tube row of the membrane wall water-cooled burner head of the present invention.

[0065] Figure 7b It is a schematic diagram of the oblong hole tube row of the membrane wall water-cooled burner head of the present invention.

[0066] Figure 8a It is a schematic diagram of welding the flat steel of the membrane wall water-cooled combustion head and the two sides of the light tube of the present invention.

[0067] Figure 8b It is a schematic diagram of single-side welding of the flat steel and the light tube of the membrane wall water-cooled combustion head of the present invention.

[0068] Figure 9a It is a schematic diagram of the combined arrangement of the spiral finned tube and the smooth tube of the water-cooled combustion head of the present invention.

[0069] Figure 9b It is a schematic diagram of the combined arrangement of the "H"-shaped finned tube and the smooth tube of the water-cooled combustion head of the present invention.

[0070] Fig.9c It is a schematic diagram of the combined arrangement of the straight "H"-shaped finned tube and the smooth tube of the water-cooled burner head of the present invention.

[0071] Fig.10a It is a schematic diagram of the arrangement of the water-cooled burner head flat steel and two rows of light tubes in combination according to the present invention.

[0072] Fig.10b It is a schematic diagram of the arrangement of the water-cooled burner head flat steel through the spacer block and light tube combination of the present invention.

[0073] Fig.10c It is a schematic diagram of the arrangement of the water-cooled burner head flat steel of the present invention in combination with two rows of light tubes through arc-shaped plate fins.

[0074] Fig.10d It is a schematic diagram of the arrangement of the water-cooled burner head flat steel of the present invention in combination with two rows of light tubes through rectangular plate fins.

[0075] Fig.10e It is a schematic diagram of the arrangement of the water-cooled burner head flat steel combined with two rows of light tubes through pin fins of the present invention.

[0076] Fig.11a The figure is an axial schematic diagram of the method for adjusting the size of the premixed gas nozzle of the water-cooled burner head of the present invention.

[0077] Fig.11b It is a front view schematic diagram of the method for adjusting the size of the premixed gas nozzle of the water-cooled burner head of the present invention.

[0078] Fig.11c It is a front view schematic diagram of the method for adjusting the nozzle size of the water-cooled combustion head pad of the present invention.

[0079] Fig.12a It is a schematic diagram of the arrangement of the channel steel and light tube of the membrane wall water-cooled combustion head of the present invention.

[0080] Figure 12b It is a schematic diagram of the arrangement of the I-beam and light tube of the membrane wall water-cooled combustion head of the present invention.

[0081] Fig.12c It is a schematic diagram of the arrangement of the arc steel and light tube of the membrane wall water-cooled combustion head of the present invention.

[0082] Fig.12d It is a schematic diagram of the arrangement of the angle steel and light tube of the membrane wall water-cooled combustion head of the present invention.

[0083] Fig.12e It is a schematic diagram of the arrangement of the small round tubes and light tubes of the membrane wall water-cooled burner head of the present invention.

[0084] Fig.12f It is a schematic diagram of the arrangement of the semicircular tubes and light tubes of the membrane wall water-cooled burner head of the present invention.

[0085] Fig.13 It is a front view schematic diagram of the overall structure of the boiler of the present invention.

[0086] Fig.14a This is a schematic diagram of the fan arrangement of the present invention.

[0087] Fig.14b This is a schematic diagram of the second fan arrangement method of the present invention.

[0088] Fig.14c This is a third schematic diagram of the fan arrangement of the present invention.

[0089] Wherein: 1: burner, 11: burner inlet, 111: gas inlet, 112: air inlet, 12: first distribution chamber, 121: gas distribution pipe, 1211: first gas distribution pipe, 1212: second gas distribution pipe, 1213: first gas nozzle, 1214: second gas nozzle, 1215: spoiler, 122: first flow balancing orifice, 123: second flow balancing orifice, 124: third flow balancing orifice, 125: spoiler column, 126: turning guide plate, 13: second distribution chamber, 131: partition, 132: distribution orifice, 14: plane heat exchange section, 141: tubular upper header, 142: parallel heat exchange tube bundle, 1421: first row of light tubes, 1422: second row of light tubes, 143: tubular lower header, 144: tubular header water inlet, 145: tubular header outlet Steam port, 15: ignition needle, 16: flat steel, 161: premixed gas spray hole, 162: pad, 163: flat steel fin, 17: weld, 18: adjustable spray hole baffle, 2: heat exchanger, 21: arc heat exchange section, 211: annular upper header, 212: inner ring heat exchange tube bundle, 213: outer ring heat exchange tube bundle, 214: downcomer, 215: annular lower header, 216: annular header water inlet, 2 17: annular header steam outlet, 218: sewage outlet, 22: sealing plate, 23: gap guide plate, 24: furnace upper bottom plate, 25: furnace lower bottom plate, 26: shell baffle, 27: radiation heating tube bundle, 28: sealing pipe, 29: connecting pipe, 3: flue, 31: flue gas header, 32: flue gas duct, 33: flue outlet, 4: economizer, 5: condenser, 6: chimney, 7: fan. DETAILED DESCRIPTION

[0090] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0091] 3, 4 and 5, a vertical water tube built-in premixed membrane wall-cooled burner provided by the present invention includes a first distribution chamber 12, a second distribution chamber 13 and a water-cooled tube bundle, the first distribution chamber 12 is provided with an air inlet, a gas distribution pipe 121 is provided in the first distribution chamber 12, and the gas distribution pipe 121 has a gas inlet 111; the first distribution chamber 12 is connected to the second distribution chamber 13; the second distribution chamber 13 includes a partition 131 and a distribution orifice plate 132, one end of the partition 131 is connected to the first distribution chamber 12, and the other end is connected to the distribution orifice plate 132; the vertical area surrounded by the partition 131 and the distribution orifice plate 132 is the second distribution chamber 13, the distribution orifice plate 132 is opposite to the water-cooled tube bundle, the water-cooled tube bundle is a membrane wall tube bundle, the membrane wall tube bundle is provided with air flow holes, and the membrane wall surface is a plane, an arc surface or a curved surface.

[0092] With reference to Fig. 1 and Fig. 2, the present invention provides a vertical water tube built-in premixed membrane wall-cooled combustion gas boiler, comprising a burner 1, a heat exchanger 2, a flue 3, an economizer 4, a condenser 5, a chimney 6 and matching boiler accessories such as a fan 7, a water pump, a gas valve group, and a controller; the burner 1 comprises a burner inlet 11, a first distribution chamber 12, a first flow-averaging orifice plate 122, a second distribution chamber 13, a distribution orifice plate 132, a planar heat exchange section 14, a tubular upper header 141, a side-by-side heat exchange tube bundle 142, a tubular lower header 143, a tubular header water inlet 144, a tubular header steam outlet 145, and an ignition needle 15;

[0093] The heat exchanger 2 includes an arc-shaped heat exchange section 21, an annular upper header 211, an inner ring heat exchange tube bundle 212, an outer ring heat exchange tube bundle 213, a downcomer 214, an annular lower header 215, an annular header water inlet 216, an annular header steam outlet 217, a sewage outlet 218, a sealing plate 22, a gap guide plate 23, a furnace upper bottom plate 24, a furnace lower bottom plate 25, an outer shell baffle 26, a radiation heating tube bundle 27, a sealing pipe 28 and a connecting pipe 29; the flue 3 includes a flue gas header 31, a flue gas duct 32 and a flue outlet 33; the burner 1, the heat exchanger 2, the flue 3, the economizer 4, the condenser 5 and the chimney 6 are connected in sequence, and the top of the outer shell baffle 26 is connected to the annular upper header 211 The bottom of the shell baffle 26 is connected to the annular lower header 215, and the side end of the shell baffle 26 is connected to the flue 3, only the inlet part of the burner 1 and the outlet part of the flue 3 are exposed; the burner 1, the heat exchanger 2 and the flue 3 form a cylindrical vertical boiler body; the burner 1 and the heat exchanger 2 surround two axially symmetrical semi-cylindrical furnaces; the burner 1 is located on the chord side of the semi-cylindrical furnace, and the heat exchanger 2 is located on the arc side of the semi-cylindrical furnace; or the burner 1 is located on the arc side of the semi-cylindrical furnace, and the heat exchanger 2 is located on the chord side of the semi-cylindrical furnace; or the burner 1 and the heat exchanger 2 are located on the two arc sides respectively; the burner 1 adopts a premixed water-cooled combustion method, including two opposite combustion surfaces, corresponding to two heat exchange areas. The mixed gas inlet 11 of the burner 1 and the flue outlet 33 of the flue 3 are both arranged on the side of the furnace.

[0094] Referring to Figures 1 and 2, the gas boiler includes five layout schemes. The preferred scheme 1 is that the burner 1 is located on one side of the semi-cylindrical furnace chord, the heat exchanger 2 is located on one side of the two curved surfaces of the two semi-cylindrical furnaces, the burner 1 takes in air on one side along the direction of the semi-cylindrical furnace chord, and exhausts air on both sides perpendicular to the air intake direction, and the burner 1 is symmetrical along the axis perpendicular to the air intake direction; the burner 1 of scheme 2 is located on both chord sides of the semi-cylindrical furnace, the heat exchanger 2 is located on both arc sides of the two semi-cylindrical furnaces, the burner 1 takes in air on both sides along the direction of the semi-cylindrical furnace chord, and exhausts air on both sides perpendicular to the air intake direction, and the burner 1 is symmetrical about the center; the burner 1 of scheme 3 is located on both arc sides of the two semi-cylindrical furnaces, the heat exchanger 2 is located on the chord side of the semi-cylindrical furnace, the burner 1 is perpendicular to the semi-cylindrical furnace Air is taken in from both sides in the direction of the chord, and air is discharged from one side in the direction of the semi-cylindrical furnace chord, and the burner 1 is axisymmetric in parallel to the air intake direction; the burner 1 and the heat exchanger 2 of scheme four are respectively located on the two arc sides of the two semi-cylindrical furnaces, the burner 1 takes in air from one side in the direction perpendicular to the direction of the semi-cylindrical furnace chord, and discharges air from one side in the other side perpendicular to the direction of the semi-cylindrical furnace chord, and the burner is axisymmetric in parallel to or perpendicular to the air intake direction; the burner 1 and the heat exchanger 2 of scheme five are respectively located on the two arc sides of the two semi-cylindrical furnaces, and the arc surface of the burner 1 is changed into a trapezoidal surface, the burner 1 takes in air from one side in the direction perpendicular to the direction of the semi-cylindrical furnace chord, and discharges air from one side in the other side perpendicular to the direction of the semi-cylindrical furnace chord, and the burner is axisymmetric in parallel to the air intake direction. The flue gas of Scheme 1 and Scheme 2 is discharged from the boiler body through two flues 3 in a direction perpendicular to the semi-cylindrical furnace chord; the flue gas of Scheme 3 is discharged from the boiler body through one flue 3 or two flues 3 in a direction parallel to the semi-cylindrical furnace chord; the flue gas of Scheme 4 and Scheme 5 is discharged from the boiler body through one flue 3 in a direction perpendicular to the semi-cylindrical furnace chord; Figure 1a , Figure 1b , Figure 1c , the direction in which the mixed gas enters the boiler body in schemes 1, 2 and 3 is perpendicular to the direction in which the flue gas leaves the boiler body. The direction in which the mixed gas enters the boiler body points to the center of the furnace, and the direction in which the flue gas leaves the boiler body points away from the center of the furnace; reference Figure 1d , Figure 1e In schemes 4 and 5, the direction in which the mixed gas enters the boiler body is parallel to the direction in which the flue gas leaves the boiler body. The direction in which the mixed gas enters the boiler body points to the center of the furnace, and the direction in which the flue gas leaves the boiler body points away from the center of the furnace. In the above schemes, when two flues 3 are required, the two flues 3 are connected through a flue gas duct 32.

[0095] refer to Figure 1a , Figure 1b , Figure 3a , Figure 3b , Figure 3c , Figure 3dThe burner 1 of Scheme 1 and Scheme 2 includes a burner inlet 11, a first distribution chamber 12, a first flow equalizing orifice plate 122, a second distribution chamber 13, a distribution orifice plate 132, a tubular upper header 141, a side-by-side heat exchange tube bundle 142, a tubular lower header 143, a tubular header water inlet 144, a tubular header steam outlet 145 and an ignition needle 15. The burner inlet 11 is a cylinder, the cross section of which is circular or square, etc., both ends of the cylinder are open, and a flange is set at one end. The flange side of the burner inlet 11 is closely connected to the fan 7, and the other end of the burner inlet 11 is connected to the first distribution chamber 12. The first distribution chamber 12 is surrounded by a cylinder in the form of a circular-to-rectangular or square-to-rectangular cylinder and a rectangular cylinder. The height of the first distribution chamber 12 is equal to the distance between the bottom of the annular upper header 211 and the top of the annular lower header 215; the first flow-averaging orifice plate 122 is welded to the rectangular cylinder side of the first distribution chamber 12, the first flow-averaging orifice plate 122 is rectangular, and circular, square or triangular spray holes are evenly arranged on the first flow-averaging orifice plate 122. The second distribution chamber 13 is welded at the rear end of the first flow-averaging orifice plate 122. The second distribution chamber 13 is approximately a prismatic space, and the cross section of the second distribution chamber 13 is scissor-shaped, right-angled trapezoid, curved right-angled trapezoid, rectangular, etc. The cross section of the second distribution chamber 13 gradually decreases or remains unchanged along the gas flow direction. One or two sides of the second distribution chamber 13 are distribution orifice plates 132. The distribution orifice plates 132 can be set to be flat, folded or curved plates according to the top cross-section of the second distribution chamber 13. Circular, square or triangular spray holes are evenly arranged on the distribution orifice plates 132. The hydraulic diameter of the spray holes is less than 4 mm. One or two rows of evenly arranged parallel heat exchange tube bundles 142 are arranged directly opposite the distribution orifice plates 132. The number of columns of the parallel heat exchange tube bundles 142 is the same as or different from the number of columns of the spray holes on the distribution orifice plates 132. The number of spray holes on the distribution orifice plate 132 is an integer multiple of the number of columns of the side-by-side heat exchange tube bundles 142. A row of side-by-side heat exchange tube bundles 142 close to the distribution orifice plate 132 is arranged directly opposite to the spray holes on the distribution orifice plate 132, that is, the gas sprayed from the spray holes of the distribution orifice plate 132 just jets to the central axis of each tube of the side-by-side heat exchange tube bundle 142 or jets evenly to its side wall. The distance between the tube wall of a row of side-by-side heat exchange tube bundles 142 close to the distribution orifice plate 132 and the distribution orifice plate 132 is 5 to 30 mm. The upper and lower ends of the side-by-side heat exchange tube bundle 142 are respectively connected to the tubular upper header 141 and the tubular lower header 143. The burner 1 can be a single burner, or two identical burners can be arranged axially or centrally symmetrically. The burner 1 of scheme one and scheme two adopts an integral burner 1 with double-sided air outlet, refer to Figure 3c The burner 1 can also be arranged in parallel with two single-sided gas outlet burners 1 in the same direction or in the opposite direction, refer to Figure 1b , Figure 3b , Figure 3d .

[0096] refer to Figure 1c , Figure 1d4 , the burner 1 of the scheme three and scheme four comprises a burner inlet 11, a first distribution chamber 12, a first flow balancing orifice plate 122, an inner ring heat exchange tube bundle 212, an outer ring heat exchange tube bundle 213, a sealing plate 22, a gap guide plate 23 and an ignition needle 15; the burner inlet 11 is a cylinder, the cylinder is an open cylindrical or square shape, a flange is welded at one end of the cylinder, the flange side of the burner inlet 11 is connected to the fan 7, the other end of the burner inlet 11 is welded in sequence with a cylinder in the form of a round to rectangular or a square to rectangular and a rectangular cylinder, a crescent-shaped cylinder is welded at the rear end of the rectangular cylinder, the round to rectangular or square to rectangular cylinder is connected with a rectangular cylinder to form a first distribution chamber 12, the crescent-shaped cylinder forms a second distribution chamber 13, and a flow balancing orifice plate can be arranged between the first distribution chamber 12 and the second distribution chamber 13. An arc-shaped distribution orifice plate 132 is arranged on the inner arc surface of the second distribution chamber 13. The distribution orifice plate 132 has uniformly distributed spray holes, which are circular and have a diameter of less than 4 mm. Uniformly arranged outer ring heat exchange tube bundles 213 and uniformly arranged inner ring heat exchange tube bundles 212 are arranged in sequence behind the distribution orifice plate 132. The diameter of the outer ring heat exchange tube bundle 213 is larger than the diameter of the inner ring heat exchange tube bundle 212. The gap formed between adjacent tubes of the outer ring heat exchange tube bundle 213 is 2-5 mm, and the gap formed between adjacent tubes of the inner ring heat exchange tube bundle 212 is 4-10 mm. The outer ring heat exchange tube bundle 213 and the inner ring heat exchange tube bundle 212 are arranged in staggered rows. The number of rows of the outer ring heat exchange tube bundle 213 is the same as the number of rows of the spray holes on the distribution orifice plate 132 or the number of rows of the spray holes on the distribution orifice plate 132 is an integral multiple of the number of rows of the outer ring heat exchange tube bundle 213. The outer ring heat exchange tube bundle 213 is directly opposite to the spray holes on the distribution orifice plate 132, that is, the gas sprayed from the spray holes of the distribution orifice plate 132 just flows to the central axis of each tube of the outer ring heat exchange tube bundle 213 or evenly flows to its side wall. The upper and lower ends of the inner ring heat exchange tube bundle 212 and the outer ring heat exchange tube bundle 213 are respectively connected to the annular upper header 211 and the annular lower header 215.

[0097] refer to Figure 1a , Figure 1b , Figure 2a , Figure 2b The heat exchanger 2 of the scheme 1 and the scheme 2 comprises an arcuate heat exchange section 21, a sealing plate 22, a slit guide plate 23, a furnace upper bottom plate 24, a furnace lower bottom plate 25, a shell baffle 26, a sealing pipe 28 and a connecting pipe 29, and the arcuate heat exchange section 21 comprises an annular upper header 211, an inner ring heat exchange tube bundle 212, an outer ring heat exchange tube bundle 213, a downcomer 214, an annular lower header 215, an annular header water inlet 216, an annular header steam outlet 217, and a sewage outlet 218;

[0098] refer to Figure 1c , Figure 1d , Figure 1e , Figure 2c , Figure 2d , Figure 2eThe heat exchanger 2 of the schemes 3, 4 and 5 comprises a planar heat exchange section 14, an annular upper header 211, an inner ring heat exchange tube bundle 212, an outer ring heat exchange tube bundle 213, a downcomer 214, an annular lower header 215, an annular header water inlet 216, an annular header steam outlet 217, a sealing plate 22, a slit guide plate 23, a furnace upper bottom plate 24, a furnace lower bottom plate 25, a radiation heating tube bundle 27 and a sealing tube 28. The planar heat exchange section 14 comprises a tubular upper header 141, a side-by-side heat exchange tube bundle 142, a tubular lower header Box 143, tubular header water inlet 144, tubular header steam outlet 145; the inner circle heat exchange tube bundle 212 and the outer circle heat exchange tube bundle 213 on the two arc sides of Scheme 3 are both burner water-cooled tube bundles, the inner circle heat exchange tube bundle 212 and the outer circle heat exchange tube bundle 213 on one arc side of Scheme 4 and Scheme 5 are burner water-cooled tube bundles, and the inner circle heat exchange tube bundle 212 and the outer circle heat exchange tube bundle 213 on the other arc side are heat exchange tube bundles; two parallel side-by-side heat exchange tube bundles 142 are set, and a gap of 50-300mm is set between the tube rows. For Scheme 3, one end of the two side-by-side heat exchange tube bundles 142 is sealed by a sealing plate 22, and the other end is a flue 3; or both sides of the two side-by-side heat exchange tube bundles 142 are flues 3, and for Schemes 4 and 5, both ends of the two side-by-side heat exchange tube bundles 142 are sealed by sealing plates 22.

[0099] refer to Figure 1a , Figure 1b , Figure 1c , Figure 1d , Figure 1e , Figure 2a , Figure 2b , Figure 2c , Figure 2d as well as Figure 2e In the five schemes, the radiation heating tube bundle 27 can be arranged or not arranged in the furnace; a half circle of the radiation heating tube bundle 27 is arranged in each of the two semi-cylindrical furnace spaces, and the radiation heating tube bundle 27 is concave inwards and is divided into three sections: an upper inclined section, a middle vertical section, and a lower inclined section. The three sections are located on the same plane, and the upper inclined section and the lower inclined section face the same direction. The top of the radiation heating tube bundle 27 is connected to the inner side or top of the annular upper header 211, and the bottom of the radiation heating tube bundle 27 is connected to the inner side or bottom of the annular lower header 215. The radiation heating tube bundle 27 is evenly arranged along the circumferential direction, and the 2-5 radiation heating tube bundles 27 on both sides of the burner 1 reduce the length of the upper inclined section and the lower inclined section.

[0100] The annular header water inlet 216 is located below the steam-water dividing line on the side of the annular upper header 211 or at the bottom, the annular header steam outlet 217 is located above the steam-water dividing line on the side of the annular upper header 211 or at the top, and the sewage outlet 218 is located on the side or bottom of the annular lower header 215. The vertical cross-sections of the annular upper header 211 and the annular lower header 215 are rectangular, circular or elliptical with chamfered corners on all sides. The annular upper header 211 is 0.4 to 0.8 m high, and the annular lower header 215 is 0.2 to 0.4 m high. Two or three circles of vertical heat exchange tube bundles are arranged between the annular upper header 211 and the annular lower header 215. The inner circle heat exchange tube bundle 212 is a plain tube, a spiral fin tube or a finned tube. When the inner circle heat exchange tube bundle 212 is a spiral fin tube, the fin height is less than 10 mm. When the inner circle heat exchange tube bundle 212 is a finned tube, the fin height is less than 10 mm. The outer circle heat exchange tube bundle 213 is an enhanced heat exchange tube bundle such as a spiral fin tube, a finned tube, a special-shaped tube, etc., and the height of the fin or fin can be 30 to 100 mm. The furnace upper bottom plate 24 is tightly welded to the bottom of the annular upper header 211, and the furnace lower bottom plate 25 is tightly welded to the top of the annular lower header 215; the annular upper header 211 is provided with a steam-water separator and multiple flange interfaces for water intake, steam exhaust, maintenance, installation of pressure gauges, thermometers, water level gauges and safety valves; the annular lower header 215 is provided with multiple flange interfaces for maintenance, sewage discharge, and temperature and pressure measurement. The parallel heat exchange tube bundles 142 of the five schemes can be additionally provided with 1 to 2 rows of bare tubes, spiral fin tubes, special-shaped tubes and (or) guide plates to enhance heat exchange. A slit guide plate 23 with a herringbone, V-shaped or triangular cross-section is arranged between two adjacent heat exchange tubes of the outer ring heat exchanger tube bundle 213, and the slit guide plate 23 is located on the inner side of the outer ring heat exchanger tube bundle 213, with the tip facing outward; or a slit guide plate 23 with a herringbone, V-shaped or triangular cross-section is arranged between two adjacent heat exchange tubes of the inner ring heat exchanger tube bundle 212, and the slit guide plate 23 is located on the outer side of the inner ring heat exchanger tube bundle 212, with the tip facing inward; or slit guide plates 23 are arranged in both the outer ring heat exchanger tube bundle 213 and the inner ring heat exchanger tube bundle 212. The two heat exchange tubes at both ends of the inner heat exchange tube bundle 212 and the outer heat exchange tube bundle 213 are both configured as bare tubes. Sealing tubes 28 are provided at the tangent points to the tube bundles at both ends of the parallel heat exchange tube bundle 142. The sealing tube 28 is a bare tube. The top and bottom of the sealing tube 28 are bent so as to be connected to the annular upper header 211 and the annular lower header 215. The sealing plate 22 is used to seal the longitudinal gap between the two bare tubes and the sealing tube 28 at the same end of the inner heat exchange tube bundle 212 and the outer heat exchange tube bundle 213. The sealing plate 22, the outer shell baffle 26, and the sealing tube 28 surround the parallel heat exchange tube bundle 142, the inner heat exchange tube bundle 212, the outer heat exchange tube bundle 213, and the radiation heating tube bundle 27 to form a heated area. A downcomer 214 is provided in the peripheral area that is not heated or is heated less, thereby forming a natural circulation steam boiler. When the downcomer 214 is not provided, a cross-flow steam or hot water boiler is formed.The parallel heat exchange tube bundle 142, the inner ring heat exchange tube bundle 212, the outer ring heat exchange tube bundle 213, and the sealing tube 28 are all connected to the header by the necking process; the outer side of the tubular upper header 141, the outer side of the tubular lower header 143, the bottom of the annular upper header 211, the top of the annular lower header 215, the bottom of the furnace upper bottom plate 24, the top of the furnace lower bottom plate 25, and the tube bundle necking are all provided with refractory mud; the inner side or outer side of the shell baffle 26, the annular upper header 211, the annular lower header 215, the furnace upper bottom plate 24, the furnace lower bottom plate 25, and the outer side of the flue 3 are all provided with insulation materials. The flue 3 includes a flue gas header 31, a flue gas duct 32, and a flue outlet 33; the flue gas header 31 is a cavity with a rectangular cross section or a cavity with a circular cross section; reference. Figure 1a , Figure 1b , Figure 2a and Figure 2b , Scheme 1 and Scheme 2 are double flues, two flue gas headers 31 are connected via a flue gas duct 32, and the flue gas in the two flue gas headers 31 is collected through the flue gas duct 32 and then discharged from the boiler body through the flue outlet 33; Figure 1c , Figure 1d , 1e , Figure 2c , Figure 2d , 2e , Scheme 3, Scheme 4 and Scheme 5 are single flue, and the flue gas in the flue header 31 is directly discharged from the boiler body through the flue outlet 33; the flue outlet 33 is directly and tightly connected to the economizer 4 through a flange or the flue outlet 33 is tightly connected to the economizer 4 through a flange after turning; the flue gas inlet end of the flue gas header 31 is tightly connected to the shell baffle 26, the annular upper header 211 and the annular lower header 215. In Scheme 1, Scheme 2, Scheme 4 and Scheme 5, the flue gas inlet end of the flue gas header 31 is tightly connected to the shell baffle 26, refer to Figure 1c and Figure 2cIn the third scheme, the smoke inlet end of the smoke header 31 passes through the outer shell baffle 26, the outer side wall of the smoke inlet end cavity is tightly connected to the outer shell baffle 26, and the end of the smoke header 31 cavity is tightly connected to the two water cooling tubes on one side of the parallel heat exchange tube bundle 142; the maximum distance between the tubular upper header 141 and the tubular lower header 143 is less than the distance between the bottom of the annular upper header 211 and the top of the annular lower header 215; the axis of the tubular upper header 141 and the tubular lower header 143 is axially opposite to each other. The two ends of the tubular header are respectively provided with a tubular header steam outlet 145 and a tubular header water inlet 144, and the tubular header steam outlet 145 and the tubular header water inlet 144 are connected to the connecting pipe 29 through a flange; the burner 1 is integrally detachable; or the maximum distance between the tubular upper header 141 and the tubular lower header 143 is greater than the distance between the bottom of the annular upper header 211 and the top of the annular lower header 215, and the two ends of the axis of the tubular upper header 141 and the tubular lower header 143 are respectively connected to the annular The annular upper header 211 is connected to the annular lower header 215, and the connection part is the inner side or top of the annular upper header 211 and the inner side or bottom of the annular lower header 215; in this case, the connecting pipe 29 is not required, and the burner 1 is partially detachable, wherein the tubular upper header 141, the parallel heat exchange tube bundle 142 and the tubular lower header 143 cannot be pulled out, and the rest of the burner 1 can be pulled out and disassembled; or the burner 1 is non-detachable; the pullable part of the burner 1 is used in a drawer manner It is connected and sealed with the annular upper header 211, the annular lower header 215, the furnace upper bottom plate 24, the furnace lower bottom plate 25 and the outer shell baffle 26, placed into the furnace through the opening of the outer shell baffle 26, and fixed under the constraint of the preset guide rail in the furnace; the connecting pipe 29 is a 180° elbow, one end of which is tightly connected to the flange on the tubular upper header 141 or the tubular lower header 143, and the other end is connected to the outer side of the annular upper header 211 or the annular lower header 215.The first flow equalizing orifice plate 122, the distribution orifice plate 132, the sealing plate 22, the upper bottom plate 24 of the furnace, the lower bottom plate 25 of the furnace, and the outer shell baffle 26 are all made of high temperature resistant and deformation resistant materials; the boiler working medium can be water or organic medium such as heat transfer oil; the side-by-side heat exchange tube bundle 142, the inner ring heat exchange tube bundle 212 and the radiation heating tube bundle 27 and other tube bundles that are in direct contact with the high-temperature flue gas are sprayed with nickel-chromium alloy; the distribution orifice plate 132 and the side-by-side heat exchange tube bundle 142 in the scheme one and the scheme two can be correspondingly set to a plane, a concave curved surface, a convex curved surface or a folded plate surface; each combustion surface is arranged with one or two ignition needles 15, and the ignition needle 15 can be provided from the side, top or bottom of the furnace The ignition needle 15 extends into the furnace, and the ignition needle 15 correspondingly passes through the sealing plate 22, the upper bottom plate 24 of the furnace or the lower bottom plate 25 of the furnace and extends into the furnace. The minimum distance between the ignition needle 15 and the outer wall of the parallel heat exchange tube bundle 142 or the outer wall of the inner circle heat exchange tube bundle 212 is 10-50mm; the upper bottom plate 24 of the furnace and the lower bottom plate 25 of the furnace are circular plates, the upper bottom plate 24 of the furnace and the bottom or the inner side of the annular upper header 211 are tightly welded, and the lower bottom plate 25 of the furnace and the top or the inner side of the annular lower header 215 are tightly welded; gaps for the parallel heat exchange tube bundle 142 and the radiation heating tube bundle 27 to pass through are correspondingly reserved on the surfaces of the upper bottom plate 24 of the furnace and the lower bottom plate 25 of the furnace, and the gaps are sealed with refractory mud.

[0101] refer to Figure 1e , 2e, 5a, Figure 5b , Figure 5c , Figure 6a , Figure 6b , Figure 6c , Figure 6d , Figure 6eThe burner 1 of scheme five comprises a burner inlet 11, a first distribution chamber 12, a second distribution chamber 13 and a water-cooled tube bundle composed of a flat heat exchange section 14 tube bundle, wherein the burner inlet 11 comprises a gas inlet 111 and an air inlet 112, the first distribution chamber 12 comprises a gas distribution pipe (121), a first flow balancing orifice plate 122, a second flow balancing orifice plate 123, a third flow balancing orifice plate 124, a spoiler column 125, and a turning guide plate 126, the gas distribution pipe 121 comprises a first gas distribution pipe 1211 and a second gas distribution pipe 1212, the first gas distribution pipe 1211 is provided with a first gas spray hole 1213, the second gas distribution pipe 1212 is provided with a second gas spray hole 1214, and the second distribution chamber 13 comprises a partition plate 131 and a distribution orifice plate 132. The burner 1 is a rectangular solid as a whole, with an air inlet 112 on the wide surface of the rectangular solid, and a gas inlet 111 on the narrow surface of the rectangular solid. The gas enters the gas distribution pipe 121 through the gas inlet 111, and the air enters the first distribution chamber 12 through the air inlet 112. The first distribution chamber 12 can be a rectangular solid. The air passes through the first flow balancing orifice plate 122, the second flow balancing orifice plate 123, and the outer side of the gas distribution pipe 121 in sequence, and then mixes with the gas sprayed from the second gas nozzle 1214. Then, the mixed gas passes through the spoiler column 125, the third flow balancing orifice plate 124 and the turning guide plate 126 to enter the second distribution chamber 13, and enters the burner water-cooled tube bundle under the action of the partition plate 131 and the distribution orifice plate 132. The air inlet 112 can be circular or square, the gas distribution pipe 121 can be a circular tube or a square tube, the first gas spray hole 1213 and the second gas spray hole 1214 can be circular holes, square holes or triangular holes. Preferably, two rows of staggered holes are arranged on the upper and lower sides of the second gas distribution pipe 1212, and spray holes of various shapes and arrangements are provided on the first flow balancing orifice plate 122, the second flow balancing orifice plate 123, the third flow balancing orifice plate 124 and the distribution orifice plate 132. The third flow balancing orifice plate 124 is arranged at the tail of the first distribution chamber 12, the turning guide plate 126 is connected to the third flow balancing orifice plate 124, the distribution orifice plate 132 is opposite to the planar heat exchange section 14, and the partition plate 131 is arranged to separate the second distribution chamber 13 and change the flow area of ​​the second distribution chamber 13. The partition plate 131, the second flow balancing orifice plate 123 and the distribution orifice plate 132 surround the second distribution chamber 13.3 to 50 spoiler columns 125 are evenly arranged along the axial direction of the gas distribution pipe 121 behind the gas distribution pipe 121. The two ends of the spoiler columns 125 are welded to the inner wall of the first distribution chamber 12. The spoiler columns 125 are columnar, and the cross section is triangular, inverted triangular, square or circular. The turning guide plate 126 forms a 180° turn, and the cross section is a right-angle "U" shape, a smooth transition "U" shape or a "V" shape. The cross section of the second distribution chamber 13 is rectangular or trapezoidal, and the second distribution chamber 13 is provided with 1 to 10 partitions 131 are arranged parallel to the flow direction of the mixed gas. The top of the partition 131 may be connected to the top of the second distribution chamber 13 or not; the bottom of the partition 131 may be connected to the top of the distribution orifice 132 or not; the left and right ends of the partition 131 may be connected to the turning guide plate 126 and the end of the second distribution chamber 13 respectively or not; the distribution orifice 132 is arranged at the tail of the second distribution chamber 13, and the distribution orifice 132 may be arranged in 1 to 3 layers. The flow area in the first distribution chamber 12 along the gas intake direction remains unchanged or gradually decreases, and the flow area in the second distribution chamber 13 along the flow direction of the mixed gas remains unchanged or gradually decreases. The gas flow directions in the first distribution chamber 12 and the second distribution chamber 13 may be opposite, vertical or at other angles, and the corresponding turning guide plate 126 forms a turn of 180°, 90° or other angles. The turning angle of the turning guide plate 126 is set by ordinary technicians in this field according to needs. The burner 1 may be a low / zero carbon fuel burner, and the low / zero carbon fuel may share a premixer with natural gas, or the low / zero carbon fuel and natural gas may be mixed with air separately.

[0102] refer to Figure 7a , Figure 7b , Figure 8a , Figure 8b The water-cooled tube bundle at the head of the burner 1 is a membrane wall tube bundle. The membrane wall surface can be a flat surface, a curved surface or an arc surface. Two adjacent smooth tubes are welded together by flat steel. The flat steel is provided with regular premixed gas spray holes from bottom to top. The center line of the spray hole is vertical or inclined to the inner and outer planes of the flat steel so as to form high-temperature flue gas recirculation zones of different degrees on the furnace surface. The airflow ejected by the premixed gas forms a built-in flue gas recirculation around the nozzle outlet to reduce NO x .

[0103] refer to Figure 5a , Figure 5b , Figure 6bA triangular or "V" shaped spoiler column 125 is arranged at the front end of the gas distribution pipe 121. The cross section of the spoiler column 125 is parallel to the cross section of the first gas distribution pipe 1211. The cross section width of the spoiler column 125 can be greater than, equal to or less than the cross section width of the gas distribution pipe 121. The gas inlet 111 is located at one end or both ends of the first gas distribution pipe 1211. The gas is introduced along one end or both ends of the first gas distribution pipe 1211. The air inlet 112 is located at the front end of the first distribution chamber 12. The first gas distribution pipe 1211 and the second gas distribution pipe 1212 are connected in the air flow direction. The first gas spray holes 1213 are evenly arranged on the interface between the first gas distribution pipe 1211 and the second gas distribution pipe 1212. The second gas spray holes are evenly arranged on the top and bottom surfaces of the second gas distribution pipe 1212. The first gas spray holes 1213 are arranged in 1 to 8 rows, and the second gas spray holes 1214 are arranged in 1 to 4 rows. The first gas spray holes 1213 and the second gas spray holes 1214 can be arranged in series or staggered. Spoiler plates 1215 are welded at the top and bottom of the interface between the first gas distribution pipe 1211 and the second gas distribution pipe 1212 .

[0104] refer to Figure 4a , Figure 4b , Figure 4c Different from the burner form of Scheme 1 and Scheme 2, the burner 1 of Scheme 3 and Scheme 4 includes a water-cooled tube bundle consisting of a burner inlet 11, a first distribution chamber 12, a second distribution chamber 13 and an arc-shaped heat exchange section 21 tube bundle.

[0105] refer to Figure 5a , Figure 5c When the mixed gas takes in parallel to the distribution orifice plate 132, 1 to 10 vertical baffles parallel to the flow direction of the mixed gas are arranged in the second distribution chamber 13 along a direction perpendicular to the flow direction of the mixed gas. The front edge of the vertical baffle is connected to the top of the second distribution chamber 13, and the rear edge of the vertical baffle is connected to the distribution orifice plate 132 or is spaced 5 to 20 mm from the distribution orifice plate 132. The top and bottom ends of the vertical baffle are respectively connected to the top and bottom surfaces of the second distribution chamber 13.

[0106] refer to Figure 5b , Figure 6a In the turning guide plate 126, 0<W1<W, 0≤h1<h, and the position where the turning guide plate 126 is connected to the third flow averaging orifice plate 124 is adjustable.

[0107] The first flow balancing orifice plate 122, the second flow balancing orifice plate 123, the third flow balancing orifice plate 124, the distribution orifice plate 132, the sealing plate 22, the furnace upper bottom plate 24, the furnace lower bottom plate 25 and the outer shell baffle 26 are all made of high temperature resistant and deformation resistant materials, and the side-by-side heat exchange tube bundle 142, the inner ring heat exchange tube bundle 212 and the radiation heating tube bundle 27 are directly in contact with the high-temperature flue gas. The surface of the tube bundle is sprayed with nickel-chromium alloy. The burner 1 is a natural gas burner, a natural gas mixed with low / zero carbon fuel burner or a pure low / zero carbon fuel burner, and the working medium of the heat exchanger 2 is water or heat transfer oil.

[0108] The flow balancing and flow disturbing components in the burner 1 can be appropriately increased, omitted or the location of the components can be changed according to different working conditions.

[0109] refer to Figure 6d , Figure 6e The first gas distribution pipe 1211 can also be placed in parallel outside the first distribution chamber 12, and one end of 3 to 20 evenly arranged second gas distribution pipes 1212 is vertically connected to the first gas distribution pipe 1211, and the other end extends into the first distribution chamber 12. The gas inlet 111 is located at one end, both ends or in the middle of the first gas distribution pipe 1211, and 1 to 3 gas inlets 111 are provided. The second gas distribution pipe 1212 is provided with evenly arranged second gas spray holes 1214 along the air flow direction, away from the air flow direction or in two directions.

[0110] refer to Figure 4a , Figure 4b , Figure 4c When the burner 1 is arranged on the arc side of the semi-cylindrical furnace, one or two single-sided burners are arranged with the outer ring heat exchange tube bundle 213 and the inner ring heat exchange tube bundle 212 as water-cooled tube bundles, the front end of the cross-section of the burner 1 is square, the rear end is crescent-shaped, and the distribution orifice plate 132 is arc-shaped; the diameter of the outer ring heat exchange tube bundle 213 is larger than the diameter of the inner ring heat exchange tube bundle 212, the gap formed between adjacent tubes of the outer ring heat exchange tube bundle 213 is 2-5mm, and the gap formed between adjacent tubes of the inner ring heat exchange tube bundle 212 is 4-10mm; the number of columns of the outer ring heat exchange tube bundle 213 is the same as the number of columns of the spray holes on the distribution orifice plate 132 or the number of columns of the spray holes on the distribution orifice plate 132 is an integer multiple of the number of columns of the outer ring heat exchange tube bundle 213, and the outer ring heat exchange tube bundle 213 is directly opposite to the spray holes on the distribution orifice plate 132.

[0111] 3, 4 and 5, the mixed gas of the gas and the air in the burner 1 can be fed perpendicularly to the distribution orifice plate 132 or parallel to the distribution orifice plate 132. When the gas is fed perpendicularly to the distribution orifice plate 132, the turning guide plate 126 is not provided, and the flow direction of the mixed gas in the first distribution chamber 12 is the same as the ejection direction of the mixed gas in the second distribution chamber 13; when the gas is fed parallel to the distribution orifice plate 132, the turning guide plate 126 is provided or not provided, and the flow direction of the mixed gas in the first distribution chamber 12 is perpendicular to the ejection direction of the gas in the second distribution chamber 13. The turning guide plate 126 is located at the junction of the first distribution chamber 12 and the second distribution chamber 13. The two sides of the turning guide plate 126 are connected to the two sides of the first distribution chamber 12 and the second distribution chamber 13. The cross-section is a right-angle "U" shape, a smoothly transitioned "U" shape, a "V" shape, an "L" shape, an "I" shape, etc.; when the turning guide plate 126 is in the "I" shape, the turning guide plate 126 is fixedly connected or hinged to the third flow equalizing orifice plate 124. In the case of hinged connection, the turning guide plate can rotate 180°.

[0112] refer to Figure 5a , Figure 5b When the mixed gas enters parallel to the distribution orifice plate 132, 1 to 10 partitions parallel to the flow direction of the mixed gas are arranged in the second distribution chamber 13 along a direction perpendicular to the flow direction of the mixed gas. The top of the vertical partition is connected to the top of the second distribution chamber 13, and the bottom of the vertical partition is connected to the top of the distribution orifice plate 132 or is spaced 5 to 20 mm apart. The two ends of the vertical partition are respectively connected to the front end and the end of the second distribution chamber 13.

[0113] refer to Figure 7a , Figure 7b , Figure 8a , Figure 8bThe water-cooled tube bundle at the head of the burner 1 is a membrane wall tube bundle, which is a tube bundle of a flat heat exchange section 14 and an arc heat exchange section 21. The membrane wall surface is a plane, an arc surface or a curved surface. Two adjacent light tubes are welded by flat steel 16. The length direction of the flat steel 16 is parallel to the light tube row. The flat steel 16 is located on the center line of the light tube row or deviates from the center line of the light tube row. Accordingly, the flat steel 16 is welded to the light tube on both sides or on one side; the thickness of the flat steel 16 is 3 to 20 mm, and The arc surface of the flat steel 16 in contact with the light tube in the thickness direction has a penetration depth of at least 3mm, and the weld 17 is connected with 100% full penetration as much as possible. The flat steel 16 is provided with regular premixed gas spray holes 161 from bottom to top, and the center line of the premixed gas spray holes is perpendicular or inclined to the flat steel 16. The premixed gas spray holes can be arranged in a single row, double rows or three rows from bottom to top. When there are more than one row of premixed gas spray holes, the positions of the adjacent two rows of spray holes are opposite or staggered, and the premixed gas spray holes are circular, oblong, triangular or rectangular spray hole structures. The long axis of the oblong premixed gas spray hole is parallel to or perpendicular to the longitudinal center line of the tube; the vertex angle of the triangular premixed gas spray hole is a 360° rotation angle, that is, the triangle can be placed upright, inverted or tilted, and the long side of the rectangular premixed gas spray hole is parallel to or perpendicular to the longitudinal center line of the tube.

[0114] refer to Fig.10a , Fig.10b , Fig.10c , Fig.10d The length direction of the flat steel 16 at the head of the burner 1 is perpendicular to the row of light tubes. The flat steel 16 is located between two adjacent light tubes. The head of the burner 1 has at least two rows of light tubes. The flat steel 16 is welded to the first row of light tubes 1421 to form a narrow gap between the second row of light tubes 1422. The flat steel 16 can be welded with evenly arranged arc or rectangular flat steel fins 163; or the flat steel can be evenly welded with pads 162, and the cross-section of the pads 162 is square, circular or oblong. The pads 162 are welded to the row of light tubes, and evenly arranged premixed gas nozzles are formed between the light tubes, the pads 162 and the flat steel 16. The head of the burner 1 has at least one row of light tubes. The adjustable spray hole baffle 18 is used to partially block the nozzle formed by the premixed gas spray hole 161 or the pad 162. The adjustable spray hole baffle 18 is provided with a spray hole of the same size and position as the premixed gas spray hole or the pad nozzle. The adjustable spray hole baffle 18 slides along the axial direction of the membrane wall tube, and the sliding range can cover the nozzle formed by the premixed gas spray hole 161 or the pad 162. Fig.11a , Fig.11b , Fig.11c .

[0115] refer to Figure 9a , Figure 9b , Fig.9c ,refer to Fig.12a , Figure 12b , Fig.12c , Fig.12d , Fig.12e and Fig.12f The flat steel 16 at the head of the burner 1 can be a channel steel, an I-beam, an arc steel, an angle steel, a small round tube or a semicircular tube. When the flat steel is an arc steel, the curvature α is 0<α<π, and when the flat steel is an angle steel, the angle β is 0<β<180°. The water-cooled tube bundle at the head of the burner 1 can also be a combination of a fin tube and a smooth tube. The two opposite sides of the fin tube are bent or not bent, and the side of the smooth tube faces the furnace or faces away from the furnace. The fin tube is a spiral fin tube, a circular fin tube, a square fin tube or an H-shaped fin tube.

[0116] refer to Figure 2a , Figure 2b , Figure 2d and Figure 2e One or two ignition needles 15 are arranged on each combustion surface. The ignition needles 15 can extend into the furnace from the side, top or bottom of the furnace. The ignition needles 15 correspondingly pass through the sealing plate 22 or the upper bottom plate 24 or the lower bottom plate 25 of the furnace and extend into the furnace. The ignition needles 15 are 10-50 mm away from the outer wall of the parallel heat exchange tube bundle 142 or the outer wall of the inner circle heat exchange tube bundle 212.

[0117] refer to Figure 1a , Figure 1b , Figure 3a , Figure 3b , Figure 3c , Figure 3d When the burner is arranged on the chord side of the semi-cylindrical furnace, a double-sided burner or two single-sided burners are arranged with the side-by-side heat exchange tube bundle as a water-cooled tube bundle, and the burner flow area gradually decreases from the burner inlet to the burner end; when a double-sided burner is arranged, the burner takes in air on one side along the direction of the semi-cylindrical furnace chord, and exhausts air on both sides perpendicular to the air intake direction, and the burner is symmetrical along the axis perpendicular to the air intake direction; when two single-sided burners are arranged, the burner takes in air on both sides or one side along the direction of the semi-cylindrical furnace chord, and exhausts air on both sides perpendicular to the air intake direction, and the burner is centrally symmetrical or axially symmetrical.

[0118] refer to Figure 1a , Figure 1b , Figure 1c , Figure 1d , Figure 1e , Fig.13 , Fig.14a , Fig.14b and Fig.14cThe flue 3 includes a flue gas header 31, a flue gas duct 32 and a flue gas outlet 33. When the burner 1 is arranged on the chord side of the semi-cylindrical furnace, it is a double flue. The two flue gas headers 31 are connected via the flue gas duct 32. The flue gas in the two flue gas headers 31 is collected by the flue gas duct 32 and discharged from the flue gas outlet 33. When the burner 1 is arranged on the arc side of the semi-cylindrical furnace, it is a single flue. The flue gas in the flue gas header 31 is directly discharged from the flue gas outlet 33. The flue gas outlet 33 is connected to the economizer 4, the condenser 5 and the chimney 6 in sequence. The outlet of the fan 7 is connected to any one of the front, left, right and upper sides of the burner 1, and the narrow side of the fan 7 is parallel to the surface connected to the burner 1.

[0119] The gas and air enter the burner 1 through the gas inlet 111 and the air inlet 112 respectively for flow equalization and mixing, and are ignited and burned in the furnace space surrounded by the burner 1, the heat exchanger 2, the flue 3 and the outer shell baffle 26. The high-temperature flue gas generated by the combustion exchanges heat with the parallel heat exchange tube bundle 142, the radiation heating tube bundle 27, the inner circle heat exchange tube bundle 212 and the outer circle heat exchange tube bundle 213, and is then collected and discharged from the flue 3 and enters the economizer 4 and the condenser 5 for further heat exchange, and then the flue gas is discharged from the chimney 6. Water is firstly sent into the condenser 5 and the economizer 4 by the water pump, and then enters the water replenishing port of the annular upper header 211 after absorbing the sensible heat and latent heat in the flue gas. The cold water enters the annular lower header 215 through the downcomer 214. The water in the annular lower header 215 enters the annular upper header 211 through the inner ring heat exchange tube bundle 212, the outer ring heat exchange tube bundle 213 or the radiation heating tube bundle 27, or enters the annular upper header 211 through the tubular lower header 143, the side-by-side heat exchange tube bundle 142 and the tubular upper header 141 in sequence. The water in the inner ring heat exchange tube bundle 212, the outer ring heat exchange tube bundle 213, the radiation heating tube bundle 27 and the side-by-side heat exchange tube bundle 142 absorbs the furnace radiation heat and the flue gas convection heat exchange, the water temperature rises and generates steam, the steam enters the annular upper header 211, and is discharged from the steam outlet. The steam is supplied to users, and a natural circulation boiler is formed at this time. Or, the downcomer 214 is not provided, and cold water directly enters from the water replenishment port on the annular lower header 215, enters the heated tube bundle to absorb heat, and then enters the annular upper header 211 to generate steam or hot water for users. In this case, it is a cross-flow boiler.

[0120] In summary, the vertical water tube built-in premixed membrane wall-cooled combustion gas boiler described in the present invention includes a burner "furnace", a heat exchanger "pot", a flue, an economizer, a condenser, a chimney and matching boiler accessories such as fans, water pumps, gas valve groups, controllers, etc.; the burner and the heat exchanger or both are swapped, and two axisymmetric semi-cylindrical furnaces are formed by two side-by-side heat exchange tube bundles and two to three circles of water-cooled tube bundles. The burner adopts two relatively flat or semi-circular premixed membrane wall water-cooled combustion methods, and the flue gas after combustion flushes the two relatively heat exchange areas. The present invention has a compact structure, low resistance, and high heat exchange efficiency; at the same time, the premixed water-cooled combustion temperature is low, the load is uniform, the adjustment ratio is large, and NO xExtremely low emissions; anti-explosion, high safety, suitable for pure natural gas combustion or natural gas and low / zero carbon fuel blending or pure low / zero carbon fuel combustion.

[0121] In addition, compared with the traditional vertical water tube steam boiler, the burner and heat exchanger of the present invention are connected to the upper annular header and the lower annular header using a whole or partly detachable flange, so the burner and the heat exchanger can be inspected offline at the same time, which significantly improves the maintainability of the burner and the heat exchanger.

Claims

1. A vertical water tube built-in premixed membrane wall-cooled burner, characterized in that: The invention comprises a first distribution chamber (12), a second distribution chamber (13) and a water-cooled tube bundle, wherein the first distribution chamber (12) is provided with an air inlet (112), a gas distribution pipe (121) is provided in the first distribution chamber (12), and the gas distribution pipe (121) has a gas inlet (111); the first distribution chamber (12) is connected to the second distribution chamber (13); the second distribution chamber (13) comprises a partition plate (131) and a distribution orifice plate (132), one end of the partition plate (131) is connected to the first distribution chamber (12), and the other end is connected to the distribution orifice plate (132); the vertical area surrounded by the partition plate (131) and the distribution orifice plate (132) is the second distribution chamber (13), and the distribution orifice plate (132) is directly opposite to the water-cooled tube bundle, and the water-cooled tube bundle is a membrane wall tube bundle, and air flow holes are provided on the membrane wall tube bundle, and the membrane wall surface is a plane, an arc surface or a curved surface.

2. The vertical water tube built-in premixed membrane wall-cooled burner according to claim 1 is characterized in that: A first flow balancing orifice plate (122) and a plurality of spoiler columns (125) are arranged in the first distribution chamber (12); a second flow balancing orifice plate (123) is arranged between the first distribution chamber (12) and the second distribution chamber (13); a gas distribution pipe (121) is arranged between the first flow balancing orifice plate (122) and the second flow balancing orifice plate (123); spoiler columns (125) are arranged in front of and behind the first flow balancing orifice plate (122); the spoiler columns (125) are arranged along the length direction of the gas distribution pipe (121); both ends of the spoiler columns (125) are connected to the first distribution chamber (12); the cross section of the spoiler columns (125) is triangular, V-shaped, square or circular; in the case of a V-shaped cross section, the bending angle of the V-shape faces the incoming air; and 3 to 50 spoiler columns (125) are arranged.

3. The vertical water tube built-in premixed membrane wall-cooled burner according to claim 1, characterized in that: The gas distribution pipe (121) comprises a first gas distribution pipe (1211), a second gas distribution pipe (1212), a first gas spray hole (1213), a second gas spray hole (1214) and a spoiler (1215); a gas inlet (111) is provided at one or both ends of the first gas distribution pipe (1211), the first gas distribution pipe (1211) is connected to the second gas distribution pipe (1212), and a first gas spray hole (1213) is evenly provided on the gas outlet surface of the first gas distribution pipe (1211). holes (1213), second gas spray holes are evenly opened on the side of the second gas distribution pipe (1212); the first gas spray holes (1213) are arranged in 1 to 8 rows, and the second gas spray holes (1214) are arranged in 1 to 4 rows, the first gas spray holes (1213) are arranged in series or staggered rows, and the second gas spray holes (1214) are arranged in series or staggered rows; spoilers (1215) are welded at the top and bottom of the interface between the first gas distribution pipe (1211) and the second gas distribution pipe (1212).

4. The vertical water tube built-in premixed membrane wall-cooled burner according to claim 3 is characterized in that: The flow area in the first gas distribution pipe (1211) along the gas intake direction remains unchanged or gradually decreases, and the flow area in the second distribution chamber (13) along the mixed gas flow direction remains unchanged or gradually decreases.

5. The vertical water tube built-in premixed membrane wall-cooled burner according to claim 3 is characterized in that: The first gas distribution pipe (1211) is horizontally arranged above the first distribution chamber (12); one end of 3 to 20 evenly arranged second gas distribution pipes (1212) is vertically connected to the first gas distribution pipe (1211), and the other end extends into the first distribution chamber (12); the gas inlet (111) is located at one end, both ends and / or the middle of the first gas distribution pipe (1211); 1 to 3 gas inlets (111) are provided; and evenly arranged second gas spray holes (1214) are provided on the second gas distribution pipe (1212) along the air flow direction or away from the air flow direction or in both directions.

6. The vertical water tube built-in premixed membrane wall-cooled burner according to claim 1, characterized in that: The mixed gas of the fuel gas and the air in the burner (1) is fed perpendicularly to the distribution orifice plate (132) or parallel to the distribution orifice plate (132), and the distribution orifice plate (132) is provided in 1 to 3 layers; a third flow balancing orifice plate (124) is provided at the tail of the first distribution chamber (12), and a turning guide plate (126) is provided when the gas is fed parallel to the distribution orifice plate (132), and the turning guide plate (126) is located at the junction of the first distribution chamber (12) and the second distribution chamber (13). , the turning guide plate (126) is connected to the third flow balancing orifice plate (124); the two sides of the turning guide plate (126) are connected to the two sides of the first distribution chamber (12) and the second distribution chamber (13), and the cross section is a right-angle "U" shape, a smoothly transitioned "U" shape, a "V" shape, an "L" shape, or an "I" shape; when the turning guide plate (126) is in an "I" shape, the turning guide plate (126) is fixedly connected or hinged to the third flow balancing orifice plate (124).

7. The vertical water tube built-in premixed membrane wall-cooled burner according to claim 6, characterized in that: When the mixed gas is introduced parallel to the distribution orifice plate (132), 1 to 10 vertical partitions parallel to the flow direction of the mixed gas are arranged in the second distribution chamber (13) along a direction perpendicular to the flow direction of the mixed gas, the front edge of the vertical partition is connected to the top of the second distribution chamber (13), the rear edge of the vertical partition is connected to the distribution orifice plate (132) or is spaced 5 to 20 mm from the distribution orifice plate (132), and the top and bottom ends of the vertical partition are respectively connected to the top surface and bottom surface of the second distribution chamber (13).

8. The vertical water tube built-in premixed membrane wall-cooled burner according to claim 1, characterized in that: The membrane wall tube bundle comprises a plurality of light tubes, two adjacent light tubes are welded by flat steel (16), the length direction of the flat steel (16) is parallel to the light tube row, the flat steel (16) is located on the center line of the light tube row or deviates from the center line of the light tube row, and the flat steel (16) is welded to the light tube on both sides or on one side accordingly; the thickness of the flat steel (16) is 3 to 20 mm, and the welding penetration of the arc surface of the flat steel (16) in the thickness direction in contact with the light tube is at least 3 mm, and the flat steel (16) is provided with regular premixed gas spray holes (161) from bottom to top, i.e., the gas The flow holes, the center lines of the premixed gas spray holes (161) are perpendicular or inclined to the plane of the flat steel (16), the premixed gas spray holes (161) are in a single row, double rows or three rows, when there are more than one row of premixed gas spray holes (161), two adjacent rows of premixed gas spray holes are arranged in a row or staggered row, the premixed gas spray holes (161) are circular, oblong, triangular or rectangular; the long axis of the oblong premixed gas spray holes is parallel to or perpendicular to the longitudinal center line of the tube; the triangular premixed gas spray holes are arranged upright, inverted or inclined, and the long side of the rectangular premixed gas spray holes is parallel to or perpendicular to the longitudinal center line of the tube.

9. The vertical water tube built-in premixed membrane wall-cooled burner according to claim 1, characterized in that: The water-cooling tube bundle comprises at least two rows of light tubes, a flat steel (16) is welded to the first row of light tubes (1421), the flat steel (16) is located between the second row of light tubes (1422) and forms a gap with the second row of light tubes (1422), and evenly arranged flat steel fins (163) or pads (162) are welded to the flat steel (16); the flat steel fins (163) are arcuate or rectangular, the pads (162) have a square, circular or oblong cross section, and the pads (162) and the second row of light tubes (1422) are connected to each other. Welding is performed to form uniformly arranged air flow holes between the light tube, the cushion block (162) and the flat steel (16); an adjustable spray hole baffle (18) is provided on the flat steel (16) to block the premixed gas spray hole (161) or the air flow hole formed by the cushion block (162); the adjustable spray hole baffle (18) is provided with a premixed gas spray hole (161) having the same size and position as the air flow hole; the adjustable spray hole baffle (18) slides along the axial direction of the membrane wall tube, and the sliding range can cover the premixed gas spray hole (161).

10. The vertical water tube built-in premixed membrane wall-cooled burner according to claim 1, characterized in that: The membrane wall tube bundle includes multiple light tubes, and the light tubes are welded with channel steel, I-beam, curved steel, angle steel, small round tube or semi-circular tube. When the curved steel is welded between the light tubes, the curvature of the curved steel α =0 α <π, when welding angle steel between light pipes, the angle of angle steel β =0 β <180°.

11. The vertical water tube built-in premixed membrane wall-cooled burner according to claim 1, characterized in that: The membrane wall tube bundle is a combination of fin tubes and smooth tubes. The fin tubes are bent on opposite sides, the smooth tubes face the furnace or face away from the furnace, and the fin tubes are spiral fin tubes, circular fin tubes, square fin tubes or H-shaped fin tubes.

12. A vertical water tube built-in premixed membrane wall-cooled combustion gas boiler, characterized in that: The invention comprises a burner (1), a heat exchanger (2), a flue (3), an economizer (4), a condenser (5), a chimney (6) and a fan (7); the burner (1) and the heat exchanger (2) enclose two axially symmetrical semi-cylindrical furnaces, and two heating surfaces, a plane heat exchange section (14) and an arc-shaped heat exchange section (21), are arranged in the furnaces; the burner (1) is arranged on the chord side of the semi-cylindrical furnace, and the heat exchanger (2) is arranged on the arc side of the semi-cylindrical furnace, or the burner (1) is arranged on the arc side of the semi-cylindrical furnace, and the heat exchanger (2) is arranged on the chord side of the semi-cylindrical furnace, or the burner (1) and the heat exchanger (2) are respectively arranged on the arc sides of two semi-cylindrical furnaces; the burner (1) adopts premixed water cooling A burner, wherein a tube bundle of a planar heat exchange section (14) or an arc-shaped heat exchange section (21) is used as a water-cooled tube bundle of the burner (1); when the burner (1) is located on the chord side of a semi-cylindrical furnace, the flue gases of the two semi-cylindrical furnaces flow toward the outside of the cylinder respectively; when the burner (1) is located on the arc side of the semi-cylindrical furnace, the two semi-cylindrical furnaces are connected, and the flue gases flow into the cylinder or flow into the cylinder from one side and out from the other side; the burner (1), the heat exchanger (2), the flue (3), the economizer (4), the condenser (5) and the chimney (6) are connected along the direction of the flue gas flow; the burner (1) adopts the vertical water tube built-in premixed membrane wall-cooled burner as described in any one of claims 1 to 11.

13. The vertical water tube built-in premixed membrane wall-cooled combustion gas boiler according to claim 12, characterized in that: The planar heat exchange section (14) comprises a tubular upper header (141), a parallel heat exchange tube bundle (142) and a tubular lower header (143); the two ends of the parallel heat exchange tube bundle (142) are respectively connected to the tubular upper header (141) and the tubular lower header (143); the arc-shaped heat exchange section (21) comprises an annular upper header (211), an inner ring heat exchange tube bundle (212), an outer ring heat exchange tube bundle (213) and an annular lower header (215); the outer ring heat exchange tube bundle (213) and the inner ring heat exchange tube bundle (21 2) arranged along a semi-cylindrical surface, with the outer heat exchange tube bundle (213) and the inner heat exchange tube bundle (212) connected at both ends to an annular upper header (211) and an annular lower header (215); the outer heat exchange tube bundle (213) and the inner heat exchange tube bundle (212) are arranged in staggered rows; the bottom end of the annular upper header (211) and the top end of the annular lower header (215) are respectively sealedly connected to a furnace upper bottom plate (24) and a furnace lower bottom plate (25); and an outer shell baffle (26) is arranged outside the two semi-cylindrical furnaces.

14. The vertical water tube built-in premixed membrane wall-cooled combustion gas boiler according to claim 12, characterized in that: When the burner (1) is arranged on the side of the semi-cylindrical furnace chord, a double-sided burner or two single-sided burners are arranged with a side-by-side heat exchange tube bundle (142) as a water-cooled tube bundle, and the flow area of ​​the burner (1) gradually decreases from the burner inlet to the burner end; when a double-sided burner is arranged, the burner (1) takes in air on one side along the direction of the semi-cylindrical furnace chord, and exhausts air on both sides perpendicular to the air intake direction, and the burner (1) is symmetrical along the axis perpendicular to the air intake direction; when two single-sided burners are arranged, the burner (1) takes in air on both sides or takes in air on one side along the direction of the semi-cylindrical furnace chord, and exhausts air on both sides perpendicular to the air intake direction, and the burner (1) is centrally symmetrical or axisymmetric.

15. The vertical water tube built-in premixed membrane wall-cooled combustion gas boiler according to claim 12, characterized in that: The flue (3) comprises a flue gas header (31), a flue gas duct (32) and a flue gas outlet (33). When the burner (1) is arranged on the chord side of the semi-cylindrical furnace, it is a double flue. The two flue gas headers (31) are connected via the flue gas duct (32). The flue gas in the two flue gas headers (31) is collected via the flue gas duct (32) and discharged from the flue gas outlet (33). When the burner (1) is arranged on the arc side of the semi-cylindrical furnace, it is a single flue. The flue gas in the flue gas header (31) is directly discharged from the flue gas outlet (33). The flue gas outlet (33) is connected to the economizer (4), the condenser (5) and the chimney (6) in sequence. The outlet of the fan (7) is connected to the burner (1), and the narrow surface of the fan (7) is parallel to the corresponding connection surface of the burner (1).

16. The vertical water tube built-in premixed membrane wall-cooled combustion gas boiler according to claim 13, characterized in that: When the maximum distance between the tubular upper header (141) and the tubular lower header (143) is smaller than the distance between the bottom of the annular upper header (211) and the top of the annular lower header (215), the burner (1) is integrally detachable, and the tubular upper header (141) and the tubular lower header (143) are provided with a tubular header steam outlet (145) and a tubular header water inlet (144) at both ends of the axial direction, respectively. The tubular header steam outlet (145) and the tubular header water inlet (144) are connected to a connecting pipe (29) via a flange. The connecting pipe (29) is a 180° elbow, one end of which is tightly connected to a flange on the tubular upper header (141) or the tubular lower header (143), and the other end is connected to the outer side of the annular upper header (211) or the annular lower header (215); the space between the tubular upper header (141) and the tubular lower header (143) is When the maximum distance is greater than the distance between the bottom of the annular upper header (211) and the top of the annular lower header (215), the burner (1) is partially detachable, and the remaining burner (1) parts except the tubular upper header (141), the parallel heat exchange tube bundle (142) and the tubular lower header (143) can be pulled out in the horizontal direction; the two ends of the axis of the tubular upper header (141) and the tubular lower header (143) are respectively connected to the annular upper header (211) and the annular lower header (215), and the connection parts are the inner side surface or the top of the annular upper header (211) and the inner side surface or the bottom of the annular lower header (215); the detachable part of the burner (1) is connected and sealed with the annular upper header (211), the annular lower header (215), the furnace upper bottom plate (24), the furnace lower bottom plate (25) and the shell baffle (26) by using a drawer structure.

17. The vertical water tube built-in premixed membrane wall-cooled combustion gas boiler according to claim 13, characterized in that: When the burner (1) is arranged on the chord side of the semi-cylindrical furnace, a flat heat exchange section (14) tube bundle is used as a water-cooling tube bundle of the burner (1), and the flue (3) is arranged outside the arcuate surfaces of the two semi-cylindrical furnaces; when the burner (1) is arranged on the arcuate side of the semi-cylindrical furnace, an outer ring heat exchange tube bundle (213) and an inner ring heat exchange tube bundle (212) arranged along the semi-cylindrical surface are used as the water-cooling tube bundle of the burner, and the flue (3) is arranged on the side between the two semi-cylindrical furnaces or outside the other arcuate surface of the semi-cylindrical furnace.

18. The vertical water tube built-in premixed membrane wall-cooled combustion gas boiler according to claim 13, characterized in that: A downcomer (214) is arranged on the periphery of the heating surface of the heat exchanger (2), and two ends of the downcomer (214) are connected to an annular upper header (211) and an annular lower header (215), thereby forming a natural circulation steam boiler.

19. The vertical water tube built-in premixed membrane wall-cooled combustion gas boiler according to claim 13, characterized in that: A radiation heating tube bundle (27) is arranged in the semi-cylindrical furnace. The radiation heating tube bundle (27) is inwardly concave around a circumference and is divided into three sections: an upper inclined section, a middle vertical section, and a lower inclined section. The three sections of a radiation heating tube are located in the same plane. The upper inclined section and the lower inclined section face the same direction. The top of the radiation heating tube bundle (27) is connected to the inner side or the top of the annular upper header (211), and the bottom of the radiation heating tube bundle (27) is connected to the inner side or the bottom of the annular lower header (215). The radiation heating tube bundle (27) is evenly arranged along the circumferential direction. The 2-5 radiation heating tube bundles (27) on both sides of the burner (1) have shortened upper inclined sections and lower inclined sections.

20. The vertical water tube built-in premixed membrane wall-cooled combustion gas boiler according to claim 13, characterized in that: The vertical cross-sections of the annular upper header (211) and the annular lower header (215) are rectangular, circular or elliptical with chamfered corners or rounded arcs on all sides. Two to three circles of vertical heat exchange tube bundles are arranged between the annular upper header (211) and the annular lower header (215). The inner circle heat exchange tube bundle (212) close to the furnace is a plain tube, a spiral fin tube or a fin tube. When the inner circle heat exchange tube bundle (212) is a spiral fin tube, the fin height is less than 10 mm. When the inner circle heat exchange tube bundle (212) is a fin tube, the fin height is less than 10 mm. The outer ring heat exchange tube bundle (213) is a reinforced heat exchange tube bundle of a spiral finned tube, a finned tube or a special-shaped tube structure, and the height of the fins is 30 to 100 mm; an annular header water inlet (216) is provided below the steam-water dividing line on the side of the annular upper header (211) or at the bottom, and an annular header steam outlet (217) is provided above the steam-water dividing line on the side of the annular upper header (211) or at the top; a sewage outlet (218) is provided on the side or at the bottom of the annular lower header (215).

21. The vertical water tube built-in premixed membrane wall-cooled combustion gas boiler according to claim 13, characterized in that: One to three circles of tube bundles are arranged at the arc-shaped heat exchange section (21), and the cross section formed by the tube bundles of the arc-shaped heat exchange section (21) is arc-shaped, trapezoidal or "V"-shaped. One to two rows of smooth tubes, spiral fin tubes, special-shaped tubes and / or slit guide plates (23) are arranged at the parallel heat exchange tube bundles (142); a slit guide plate (23) is arranged between two adjacent heat exchange tubes of the outer circle heat exchange tube bundle (213), and the slit guide plate (23) is located at the outer circle. The inner side of the heat exchange tube bundle (213); or a slit guide plate (23) is arranged between two adjacent heat exchange tubes in the inner heat exchange tube bundle (212), and the slit guide plate (23) is located outside the inner heat exchange tube bundle (212); or slit guide plates (23) are arranged in both the outer heat exchange tube bundle (213) and the inner heat exchange tube bundle (212); and an enhanced heat exchange channel is formed between the slit guide plate (23) and the outer wall of the heat exchange tube.

22. The vertical water tube built-in premixed membrane wall-cooled combustion gas boiler according to claim 13, characterized in that: The first flow balancing orifice plate (122), the second flow balancing orifice plate (123), the third flow balancing orifice plate (124), the distribution orifice plate (132), the sealing plate (22), the furnace upper bottom plate (24), the furnace lower bottom plate (25) and the outer shell baffle (26) are all made of high temperature resistant and deformation resistant materials; the tube bundle surfaces of the parallel heat exchange tube bundle (142), the inner ring heat exchange tube bundle (212) and the radiation heating tube bundle (27) that are in direct contact with the high temperature flue gas are sprayed with nickel-chromium alloy; the burner (1) is a natural gas burner, a natural gas mixed with low / zero carbon fuel burner or a pure low / zero carbon fuel burner; and the working medium of the heat exchanger (2) is water or heat transfer oil.

23. The vertical water tube built-in premixed membrane wall-cooled combustion gas boiler according to claim 13, characterized in that: When the burner (1) is arranged on the arc side of a semi-cylindrical furnace, one or two single-sided burners are arranged with the outer ring heat exchange tube bundle (213) and the inner ring heat exchange tube bundle (212) as water-cooled tube bundles, the front end of the cross section of the burner (1) is square, the rear end is crescent-shaped, and the distribution orifice plate (132) is arc-shaped; the diameter of the outer ring heat exchange tube bundle (213) is larger than the diameter of the inner ring heat exchange tube bundle (212); the gap formed between adjacent tubes of the outer ring heat exchange tube bundle (213) is 2-5 mm, and the gap formed between adjacent tubes of the inner ring heat exchange tube bundle (212) is 4-10 mm; the number of columns of the outer ring heat exchange tube bundle (213) is the same as the number of columns of spray holes on the distribution orifice plate (132) or the number of columns of spray holes on the distribution orifice plate (132) is an integer multiple of the number of columns of the outer ring heat exchange tube bundle (213), and the spray holes on the outer ring heat exchange tube bundle (213) and the distribution orifice plate (132) are directly opposite.

24. The vertical water tube built-in premixed membrane wall-cooled combustion gas boiler according to claim 13, characterized in that: The two heat exchange tubes at both ends of the inner ring heat exchange tube bundle (212) and the outer ring heat exchange tube bundle (213) are both configured as bare tubes. A sealing tube (28) is provided between the bare tube and the tube bundles at both ends of the parallel heat exchange tube bundle (142). The sealing tube (28) is a bare tube. The sealing tube (28) is tangent to the tube bundles at both ends of the parallel heat exchange tube bundle (142). Both ends of the sealing tube (28) are respectively connected to the annular upper header (211) and the annular lower header (215). Bend structures are provided at both ends of the sealing tube (28). A sealing plate (22) is provided to seal the longitudinal gap between the two bare tubes at the same end of the inner ring heat exchange tube bundle (212) and the outer ring heat exchange tube bundle (213), the sealing tube (28), and one end or both ends of the parallel heat exchange tube bundle (142) when the burner (1) is located on the arc side of the semi-cylindrical furnace.

25. The vertical water tube built-in premixed membrane wall-cooled combustion gas boiler according to claim 24, characterized in that: One or two ignition needles (15) are arranged on each combustion surface. The ignition needles (15) can extend into the furnace from the side, top or bottom of the furnace. The ignition needles (15) correspondingly pass through the sealing plate (22) or the upper bottom plate (24) or the lower bottom plate (25) of the furnace and extend into the furnace. The ignition needles (15) are 10-50 mm away from the outer wall of the parallel heat exchange tube bundle (142) or the outer wall of the inner circle heat exchange tube bundle (212).

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