Heat pipe type premixed water cooling inter-pipe combustion steam generator boiler and operation method

Abstract

The invention discloses a heat pipe type premixed water cooling inter-pipe combustion steam generator boiler and an operation method, the boiler is vertically arranged and comprises a steam generator, the steam generator is connected with an upper header through a downcomer I and an ascending gas guide pipe, and the steam generator is connected with a lower header through a downcomer II; the upper header and the lower header are communicated through the left and right membrane water-cooled walls, the front wall micropore combustion membrane wall, the heat exchange light tube bundle and the finned tube bundle; an area enclosed by the left and right membrane water-cooled walls, the front wall micropore combustion membrane wall, the heat exchange light tube bundle and the finned tube bundle is a hearth; a condensed steam heat exchange pipe is arranged in the steam generator and is connected with a water inlet and a water outlet of the steam generator; the energy-saving condenser and the air pre-heater are arranged behind the hearth, the overall structure is compact, and water vapor can be fully condensed; boiler feed water is indirectly heated through the steam generator, water circulation in the steam generator is promoted, the scaling risk in a boiler body pipe is eliminated, and the operation stability of the steam generator is improved.

Description

Technical Field

[0001] The invention relates to the technical field of steam generators, and in particular to a hot tube type premixed water-cooled inter-tube combustion steam generator boiler and an operating method thereof. Background Art

[0002] Heat pipe steam generators are widely used in industrial and commercial fields, such as chemical, pharmaceutical, food processing, textile printing and dyeing, construction, power industry, hotels, guesthouses, hospitals, and commercial laundries. Heat pipe steam generators have the characteristics of low water quality requirements, low furnace scaling, safety and reliability, convenient maintenance, long service life, and significant energy saving. They can operate stably under various working conditions, effectively recover waste heat, and improve energy utilization. They are suitable for steam demand scenarios in many industrial and commercial fields.

[0003] There are many types of steam generator boilers on the market, but existing steam generator boilers, such as the CN117685551A high-power water-cooled premixed steam boiler applied for by Zhejiang Liju Thermal Energy Equipment Co., Ltd., are relatively complex. They are operated by multiple components such as the combustion furnace body, water tank, combustion system, and steam-water separator. Once a key component fails, it is difficult and costly to troubleshoot and repair it. It has strict requirements on water quality. Impurities in the water are easy to scale inside the water tank, steam-water separator, etc., affecting the heat transfer efficiency and steam generation quality, and increasing the frequency and cost of maintenance. In terms of operational stability, if the combustion system has uneven fuel premixing, it may cause unstable combustion or even flameout, affecting the continuous and stable supply of steam. The initial investment cost is high, and the cost of purchasing equipment is high due to the technical content and precision requirements of components. For example, the CN215982473U indirect steam boiler applied for by Zhejiang Liju Water Heater Co., Ltd. has a high thermal efficiency. It exchanges heat through the metal surface, resulting in large heat losses and high steam consumption, which increases operating costs. In terms of water quality and maintenance, there are requirements for water quality. Impurities in the water can easily cause scaling of the heat exchanger, affecting heat transfer and equipment life. Regular inspection and cleaning are required, and the maintenance cost and workload are high. From the perspective of equipment and cost, the structure is complex, with many components, a large area, difficult installation and commissioning, and high procurement costs. Operation also needs to take into account maintenance, parts replacement and other costs.

[0004] Water-cooled premixed combustion technology and various folded-fin spiral fin tube strengthening technologies have been widely used in gas boilers, but the heat flux density on the water-cooled combustion surface and the fire-facing side of the folded-fin spiral fin tube is huge, and boiler water is prone to scaling in these areas. Summary of the invention

[0005] To solve the problems existing in the steam generator, the object of the present invention is to provide a steam generator with heat pipe type water-cooled premixed combustion, in which the steam generated by the furnace body exchanges heat with the boiler feed water in the steam generator, and after condensation, the steam returns to the furnace body to eliminate the risk of scaling of the water pipes in the furnace body of the steam generator; an energy-saving condenser and an air preheater are equipped to make full use of the waste heat of the flue gas and improve the thermal efficiency of the steam generator; a new type of finned tube bundle is adopted to increase the heat exchange area and reduce the size of the furnace body.

[0006] To achieve the above object, on the one hand, the present invention provides a steam generator boiler with heat pipe type premixed water-cooled inter-tube combustion. The boiler is vertically arranged and includes a steam generator. The steam generator is connected to the upper header through the first downcomer and the rising gas duct, and the steam generator is connected to the lower header through the second downcomer. The upper header and the lower header are connected through the left and right membrane water walls, heat exchange smooth tube bundles, and finned tube bundles; the area surrounded by the left and right membrane water walls, heat exchange smooth tube bundles, and finned tube bundles is the furnace; a condensing heat exchange tube is arranged in the steam generator, and the condensing heat exchange tube is connected to the water inlet and the water outlet of the steam generator; an energy-saving condenser is arranged behind the furnace, and the water outlet of the energy-saving condenser is connected to the water inlet of the steam generator; the number and diameter of the first downcomer, the rising gas duct, and the second downcomer are adjusted according to the boiler power.

[0007] Furthermore, a burner distribution head is arranged in front of the heat exchange smooth tube bundle. The area of the burner distribution head covering the heat exchange smooth tube bundle is the front wall micro-hole combustion membrane wall. The energy-saving condenser is sequentially connected to the air preheater and the fan. The air outlet of the air preheater is connected to the air inlet of the burner distribution head through a duct, and a chimney is arranged above the air preheater.

[0008] Furthermore, the front wall micro-hole combustion membrane wall includes micro-hole plates and water-cooled tube bundles arranged alternately and connected to each other; a plurality of micro-holes are formed in the micro-hole plates, the diameter of the micro-holes is less than 2.4 mm, and the distance between adjacent micro-holes is greater than 2.5 times the aperture and less than 10 times the aperture; the arrangement of the micro-holes adopts in-line arrangement, staggered arrangement or honeycomb arrangement.

[0009] Furthermore, a support is arranged at the bottom. The support is made of I-beam, and the bases of the lower header, the energy-saving condenser, the air preheater, and the fan are detachably connected to the support.

[0010] Furthermore, the cross-section of the condensing heat exchange tube bundle is in a honeycomb shape, and the distance between adjacent two condensing heat exchange tubes is equal.

[0011] Furthermore, the first downcomer is arranged inside the ascending steam pipe to form a sleeve structure. The condensed water flows from the first downcomer into the upper header, and the steam flows into the steam generator from the interlayer between the ascending steam pipe and the first downcomer. The steam generator is horizontally arranged, and a baffle is provided in the steam generator. The baffle is arc-shaped. Along the inner wall of the steam generator, there is a gap between the baffle and the inner wall of the steam generator, and the gap communicates with the steam from the interlayer between the ascending steam pipe and the first downcomer. Or the steam generator adopts an inclined steam generator. The ascending steam pipe is connected to the upper part of the inclined steam generator, and the interfaces of the first downcomer and the second downcomer are arranged at the same end of the inclined steam generator. Or the steam generator adopts a V-shaped steam generator. The V-shaped steam generator includes two inclined cylinders, presenting a V shape. The steam from the outlet of the upper header enters the upper parts of both ends of the V-shaped steam generator through the ascending steam pipe, and the interfaces of the first downcomer and the second downcomer are arranged in the middle of the V-shaped steam generator. Or the steam generator adopts a two-stage steam generator. One section of the two-stage steam generator is an inclined cylindrical steam generator, and the other section is a horizontally placed cylindrical steam generator. The steam from the outlet of the upper header enters the upper part of the two-stage steam generator through the ascending steam pipe, and the interfaces of the first downcomer and the second downcomer are arranged at the bottom of the horizontally placed cylindrical steam generator. Or the steam generator adopts an L-shaped steam generator. The L-shaped steam generator is in the shape of an L. The steam generator is divided into two sections, one section is a vertically placed steam generator, and the other section is a horizontally placed steam generator, and the two ends are connected by an arc. The steam from the outlet of the upper header enters the upper part of the L-shaped steam generator through the ascending steam pipe, and the interfaces of the first downcomer and the second downcomer are arranged at the bottom of the horizontally placed steam generator.

[0012] Furthermore, the steam generator adopts a heat exchange method in which water vapor flows inside the tubes. The ascending steam pipe is connected to the upper part of the steam generator, and the first downcomer and the second downcomer are connected to the lower part of the steam generator. The water vapor enters the tube bundle of the steam generator from the ascending steam pipe. Water enters the shell side of the steam generator through the water inlet of the steam generator and exchanges heat with the water vapor in the condensing heat exchange tubes, and then flows out from the steam outlet of the steam generator.

[0013] Furthermore, multiple groups of steam generators are provided, and the multiple groups of steam generators are arranged obliquely, the lower ends of the steam generators are connected to the steam generator water inlet headers, the high ends of the steam generators are connected to the steam generator steam outlet headers, and each group of steam generators is connected to the upper headers through multiple ascending steam pipes. Furthermore, according to the heat exchange amount and the design end difference of the boiler body, the finned heat exchange tube bundles are provided with one row, two rows or more rows; each finned heat exchange tube in the finned heat exchange tube bundle is provided with fins with a symmetrical structure about the center plane, and the center plane is parallel to the flue gas flow direction; the fins facing the flue gas direction are triangular or curved, and the parts away from the flue gas direction are rectangular or curved; the fins on two adjacent finned heat exchange tubes are staggered along the tube axis direction; the fins on two adjacent finned heat exchange tubes are in contact or interlaced arrangement; a flow-around structure is provided on the fins, and the flow-around structure is a spherical, diamond-shaped, or triangular protrusion formed by stamping; the thickness of the fins is 0.4 to 4 mm, and the distance between two adjacent fins is 1 mm to 10 mm.

[0014] On the other hand, the present invention provides an operation method of the above-mentioned hot tube type premixed water-cooled tube-intercombustion steam generator boiler, the premixed gas is ignited and burned on the furnace side of the front wall microporous combustion membrane wall, the flue gas generated by the combustion passes through the bare tube bundle and the finned tube bundle in turn, the flue gas bare tube bundle and the finned tube bundle are cooled and then enter the energy-saving condenser, the flue gas exchanges heat with water in the energy-saving condenser, the water heated by the flue gas enters the steam generator, and the flue gas enters the downstream after further cooling; the water in the lower header is the water condensed in the steam generator, and the downcomer enters The water vapor in the upper header enters the steam generator through the ascending steam pipe, and exchanges heat with the condensing heat exchange tubes in the steam generator. The water vapor outside the condensing heat exchange tubes condenses into water and gathers under the steam generator. It flows into the upper header and the lower header through the downcomer 1 and downcomer 2, forming a self-circulating water supply for the steam generator. The water in the condensing heat exchange tubes heats up and flows out of the boiler to the user end.

[0015] Furthermore, the gas and air are mixed in the burner distribution head and evenly sent to the front wall microporous combustion membrane wall. The premixed gas is ignited and burned on the furnace side of the front wall microporous combustion membrane wall. The flue gas is further cooled and enters the air preheater. The flue gas and the air in the pipe exchange heat. The flue gas after heat exchange is discharged through the chimney, and the preheated air is sent to the burner distribution head through the air duct.

[0016] Furthermore, the preheated air enters the burner distribution head from above through the air duct. There is a fuel inlet provided on the burner distribution head, and the air and fuel are evenly mixed in the burner distribution head; the preheated air enters the burner distribution head from below through the air duct, and there is a fuel inlet provided near the burner distribution head. After the fuel enters from the fuel inlet, it is evenly mixed in the burner distribution head; for a boiler with a blower connected to the burner distribution head, the preheated air and fuel are evenly mixed in the burner distribution head, and there are fuel inlets arranged on the burner distribution head.

[0017] Compared with the prior art, the present invention has at least the following beneficial effects: A steam generator boiler with heat pipe type premixed water-cooled inter-tube combustion of the present invention indirectly heats the boiler feed water through a steam generator, promotes the water circulation inside the steam generator, eliminates the risk of scaling in the furnace tubes, and improves the operation stability of the steam generator.

[0018] Furthermore, the core heat exchange element, the finned tube, has a simple structure, can be arranged in a cross pattern, is applicable to boilers with various capacities between 0.1t and 20t, and is easy to be mass-produced and assembled.

[0019] Furthermore, a steam generator boiler with heat pipe type premixed water-cooled inter-tube combustion of the present invention adopts an integrated skid-mounted design, integrating an energy-saving condenser, an air preheater, a blower, and a furnace body on the same support. It has a compact structure, is convenient for transportation and installation, and the boiler thermal efficiency can reach more than 103%.

[0020] Furthermore, the steam generator adopts ways such as V-shaped, L-shaped, and inclined arrangement to further promote the water circulation inside the steam generator and eliminate the risk of scaling in the furnace tubes.

[0021] Furthermore, baffles are arranged inside the horizontal steam generator. The water vapor entering from the upper header is restricted by the baffles and the steam generator shell and flows upward from bottom to top to the highest point of the steam generator, and then exchanges heat with the condensing heat exchange tubes from top to bottom. The water in the condensing tubes enters from the steam generator water inlet and flows upward along the serpentine arranged tube bundles, and flows out from the steam generator water outlet. The water vapor condenses into water after passing through the condensing tubes and converges below the steam generator, and then flows into the upper header and the lower header after passing through the downcomer one and the downcomer two; the water and water vapor in the tubes flow in opposite directions to form a full countercurrent heat exchange. The smooth tubes in the steam generator are arranged in a honeycomb pattern, and the distance between adjacent tubes is the same.

[0022] Furthermore, the starting point of the ascending steam guide pipe is above the upper header, and the end point of the ascending steam guide pipe is above the steam generator. Steam flows out from above the upper header and enters from above the steam generator. When the steam passes through the conduit and enters from above the steam generator, it can form a full countercurrent with the water in the heat exchange tube bundle, and at the same time, it can separate the steam and the water condensed and collected below the steam generator; the steam can also enter the tube bundle of the steam generator from the ascending air duct. At the same time, the user's water exchanges heat with the steam inside the tube outside the tube.

[0023] Furthermore, 1 to 10 groups of steam generators are arranged above or on the side of the boiler. The steam in the upper header enters multiple groups of steam generators through the ascending steam guide pipes. The condensed water in multiple groups of steam generators is respectively sent into the upper header and the lower header through the downcomers. When one or more groups of steam generators are blocked due to scaling and cannot be used, the remaining steam generators can still operate and will not cause the boiler to shut down; and it is possible to repair the faulty steam generator while the boiler is running without shutting down.

[0024] Furthermore, the flue gas at the furnace outlet is further utilized in the energy-saving condenser. The flue gas outlet of the furnace is connected to the flue gas inlet of the energy-saving condenser. After the flue gas enters the energy-saving condenser, it flows into the upper part of the energy-saving condenser along the flue. In the energy-saving condenser, the flue gas flows from top to bottom, and the water in the pipeline flows from bottom to top, forming a full countercurrent. After the water in the pipeline is heated, it enters the lower header through the water outlet of the energy-saving condenser. After the flue gas exits the energy-saving condenser, it enters the air preheater through the flue gas inlet of the air preheater. The flue gas flows from bottom to top in the air preheater and exchanges heat with the air in the pipeline. The air in the pipeline enters from the air inlet of the upper air preheater, and the heated air enters the burner distribution head and mixes with the gas.

[0025] Furthermore, when no smooth tubes are arranged, the curved fins run through from front to back, and the minimum height of the fins is less than 10 mm, which is beneficial to reducing the temperature of the fins and preventing the fins from overheating.

[0026] Furthermore, the fins of adjacent finned tubes are in contact with each other, and the flue gas can only flow through the gaps between the upper and lower fins; the adjacent finned tubes on the left and right can be staggered from each other to further reduce the flue gas flow area; the flow-around structure on the fin surface can further disturb the flue gas.

[0027] Furthermore, for the steam generator boiler with heat pipe type premixed water-cooled inter-tube combustion of the present invention, modular steam generators are adopted, and multiple groups of steam generators are equipped. Even if one group of steam generators is blocked due to scaling on the water supply side, other groups of steam generators can still operate, realizing maintenance without shutting down the boiler. Description of the Drawings

[0028] Figure 1a is the overall schematic diagram of the heat pipe type steam generator boiler of the present invention.Figure 1b is the cross-sectional view of the furnace body of the present invention, where Figure 1c is the schematic diagram of the micro-porous combustion membrane wall of the front wall of the present invention.

[0029] Figure 2a is the front elevation sectional view schematic diagram of a steam generator boiler with heat pipe type premixed water-cooled inter-tube combustion, Figure 2b is the side elevation sectional view schematic diagram of a steam generator boiler with heat pipe type premixed water-cooled inter-tube combustion, Figure 2c is the front elevation sectional view schematic diagram of the sleeve steam generating tube of a steam generator boiler with heat pipe type premixed water-cooled inter-tube combustion, Figure 2d is the side elevation sectional view schematic diagram of the sleeve steam generator of a steam generator boiler with heat pipe type premixed water-cooled inter-tube combustion.

[0030] Figure 3a is the overall schematic diagram of an inclined steam generator of a steam generator boiler with heat pipe type premixed water-cooled inter-tube combustion, Figure 3b is the side elevation sectional view schematic diagram of an inclined steam generator of a steam generator boiler with heat pipe type premixed water-cooled inter-tube combustion.

[0031] Figure 4a is the overall schematic diagram of a V-shaped steam generator of a steam generator boiler with heat pipe type premixed water-cooled inter-tube combustion, Figure 4b is the side elevation sectional view of a V-shaped steam generator of a steam generator boiler with heat pipe type premixed water-cooled inter-tube combustion.

[0032] Figure 5a is the overall diagram of an L-shaped steam generator of a steam generator boiler with heat pipe type premixed water-cooled inter-tube combustion, Figure 5b is the side elevation sectional view of an L-shaped steam generator of a steam generator boiler with heat pipe type premixed water-cooled inter-tube combustion.

[0033] Figure 6a is the overall diagram of a two-stage steam generator of a steam generator boiler with heat pipe type premixed water-cooled inter-tube combustion, Figure 6b is the side elevation sectional view of a two-stage steam generator of a steam generator boiler with heat pipe type premixed water-cooled inter-tube combustion.

[0034] Figure 7 is the overall schematic diagram of multiple steam generators of a steam generator boiler with heat pipe type premixed water-cooled inter-tube combustion of the present invention.

[0035] Figure 8a is the overall schematic diagram of the heat exchange form where steam of a steam generator boiler with heat pipe type premixed water-cooled inter-tube combustion of the present invention passes through the inside of the tube and water passes through the outside of the tube, Figure 8b is the front elevation sectional view schematic diagram of the steam generator.

[0036] Figure 9a It is a fin with a triangular front half and a rectangular rear half, and the fin is adjacent to the structural schematic diagram; Figure 9b It is a fin with a triangular front half and a rectangular rear half, and the fin has an interleaved structure schematic diagram; Figure 9c It is a fin with a curved front half and a rectangular rear half, and the fin is adjacent to the structural schematic diagram; Figure 9d It is a fin with a curved front half and a rectangular rear half, and the fin has an interleaved structure schematic diagram; Figure 9e It is a fin with a curve running through the front and back; Figure 9f It is a structural schematic diagram of a fin with a spoiler structure.

[0037] Figure 10a It is a front view of an energy-saving condenser of a steam generator boiler with a heat pipe type premixed water-cooled inter-tube combustion of the present invention, Figure 10b It is a side view of an energy-saving condenser of a steam generator boiler with a heat pipe type premixed water-cooled inter-tube combustion of the present invention.

[0038] Figure 11a It is an air preheater when the fan of a steam generator boiler with a heat pipe type premixed water-cooled inter-tube combustion of the present invention is connected to the air preheater, Figure 11b It is an air preheater when the fan of a steam generator boiler with a heat pipe type premixed water-cooled inter-tube combustion of the present invention is connected to the burner.

[0039] Figure 12a It is an overall front view in which the air at the outlet of the air preheater enters from the upper end of the burner, where Figure 12b It is an overall front view in which the air at the outlet of the air preheater enters from the lower end of the burner, where Figure 12c It is a front view of the fan connected to the burner distribution head.

[0040] In the attached drawings, 1 - support, 2 - lower header, 3 - left and right membrane water walls, 4 - fuel inlet, 5 - burner distribution head, 6 - front wall micro - pore combustion membrane wall, 61 - micro - pore plate, 62 - water - cooled tube bundle, 7 - downcomer two, 8 - steam generator, 9 - rising steam pipe, 10 - downcomer one, 11 - upper header, 12 - energy - saving condenser, 13 - chimney, 14 - air preheater, 15 - fan, 16 - air duct, 17 - heat - exchange smooth tube bundle, 18 - finned tube bundle, 20 - condensing heat - exchange tube, 201 - steam generator tube bundle, 21 - steam generator water inlet, 22 - steam generator steam outlet, 23 - baffle, 24 - steam generator heat - exchange tube tube sheet, 25 - steam generator steam outlet header, 26 - steam generator water inlet header, 29 - energy - saving condenser heat - exchange smooth tube, 31 - energy - saving condenser flue gas outlet, 32 - energy - saving condenser flue gas inlet, 33 - air preheater flue gas inlet, 34 - turning flue chamber, 35 - air preheater air inlet, 36 - air preheater air outlet, 37 - air preheater heat - exchange smooth tube. Specific implementation method The invention will be described in detail below in conjunction with the attached drawings and the specific implementation method.

[0042] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0043] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "one side", "one end", "one side" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention.

[0044] The object of the present invention is to provide a heat - pipe type water - cooled premixed combustion steam generator. Pure water is used for heat exchange in the furnace body, and the pure water evaporates into steam to indirectly heat the feed water entering the boiler, which can effectively solve the problem that the scaling of the furnace body water pipes affects the safe operation of the steam generator. At the same time, an integrated design is adopted to implant an air preheater to further utilize the waste heat of the flue gas and improve the boiler efficiency.

[0045] As shown in Figure 1, a steam generator boiler with a heat pipe type premixed water-cooled inter-tube combustion according to the present invention has the boiler arranged vertically. The boiler includes a support 1, a lower header 2, left and right membrane water walls 3, a fuel inlet 4, a burner distribution head 5, a front wall micro-hole combustion membrane wall 6, a second downcomer 7, a steam generator 8, an ascending steam pipe 9, a first downcomer 10, an upper header 11, an energy-saving condenser 12, a chimney 13, an air preheater 14, a fan 15, an air duct 16, a heat exchange smooth tube bundle 17 and a finned tube bundle 18. The space enclosed by the left and right membrane water walls 3, the front wall micro-hole combustion membrane wall 6, the heat exchange smooth tube bundle 17 and the finned tube bundle 18 is the furnace. The support 1 is made of I-beam. The burner distribution head 5 is arranged in front of the heat exchange smooth tube bundle 17, and the area of the burner distribution head 5 covering the heat exchange smooth tube bundle 17 is the front wall micro-hole combustion membrane wall 6.

[0046] Reference Figure 1c , Figure 2a , Figure 10a , Figure 10b, the support 1 supports the entire boiler; the lower header 2 is a cylindrical header, the lower header 2 is horizontally arranged, and the lower header 2 is provided with a water inlet, a blowdown port, and a water level gauge interface; the left and right membrane water walls 3 are arranged on the front side of the steam generator 8 and are connected to the heat exchange finned tube bundles 17 and 18 below the steam generator 8; the fuel inlet 4 is located on the burner distribution head; the burner distribution head 5 is connected to the front wall micro-hole combustion membrane wall 6, and preferably a fully premixed burner is adopted; the front wall micro-hole combustion membrane wall 6 includes alternately arranged micro-hole plates 61 and water-cooled tube bundles 62, the micro-hole plates 61 and the water-cooled tube bundles 62 are connected, and the micro-hole plates 61 are staggeredly distributed with micro-holes 19 with a hole diameter of 2.4 mm and a hole pitch of 6 mm; the steam generator 8 is arranged at the top, and the steam generator 8 is connected to the lower header 2 through the second downcomer 7, and the function of the second downcomer 7 is to send the condensed water in the steam generator 8 into the lower header 2; the steam generator 8 is provided with a steam inlet, a downcomer port, a water level gauge interface, a water inlet, and a water outlet; the rising steam pipe 9 is located between the steam generator and the upper header 11 and communicates the steam generator and the upper header 11; the two ends of the first downcomer 10 are respectively connected to the water outlet of the steam generator 8 and the upper header 11, and the function of the first downcomer 10 is to send the condensed water in the steam generator 8 into the upper header 11; the upper header 11 is a cylindrical header, the upper header 11 is horizontally arranged below the steam generator 8, and the upper header 11 is provided with a water inlet, a water outlet, and a water level gauge interface; the energy-saving condenser 12 is arranged behind the steam generator 8 to receive flue gas, and the energy-saving condenser 12 includes an energy-saving condenser water inlet 28, an energy-saving condenser heat exchange finned tube 29, an energy-saving condenser water outlet 30, an energy-saving condenser flue gas outlet 31, and an energy-saving condenser flue gas inlet; the chimney 13 is arranged above the air preheater 14 for discharging flue gas; the air preheater 14 is arranged behind the energy-saving condenser 12, and the air preheater 14 includes an air preheater flue gas inlet 33, a turning chamber 34, a flue gas outlet, an air preheater air inlet 35, an air preheater air outlet 36, and an air preheater heat exchange finned tube 37, and the air preheater flue gas inlet 33 is connected to the energy-saving condenser flue gas outlet 31; the fan 15 is connected to the air preheater 14; the gas and air are mixed in the burner distribution head and evenly sent to the front wall micro-hole combustion membrane wall 6, and the premixed gas is ignited and burned on the furnace side of the front wall micro-hole combustion membrane wall 6. The flue gas generated by combustion sequentially passes through a group of finned tube bundles 17 and finned tube bundles 18, and the flue gas enters the energy-saving condenser 12 after being cooled by the finned tube bundles 17 and finned tube bundles 18. The flue gas exchanges heat with water in the energy-saving condenser 12, and the water heated by the flue gas enters the steam generator 8. The flue gas is further cooled and then enters the air preheater 14, and the flue gas exchanges heat with the air in the tubes of the air preheater 14. The exchanged flue gas is discharged through the chimney 13, and the preheated air is sent into the burner distribution head 5 through the air duct 16; the water in the lower header 2 is the condensed water in the steam generator 8 and enters the lower header 2 through the second downcomer.It is evenly distributed to each heat exchange tube in the lower header 2, absorbs heat and vaporizes while flowing upward to become a steam-water mixture, rises to the upper header 11, and the water vapor in the upper header 11 enters the steam generator 8 through the rising steam guide pipe 9. In the steam generator 8, the water vapor exchanges heat with the heat exchange tubes, and the water vapor outside the tubes condenses into water, which gathers below the steam generator 8 and flows into the upper header 11 and the lower header 2 through the first downcomer 10 and the second downcomer 7, forming a self-circulation of the water used in the steam generator. After the water in the heat exchange tube bundle of the steam generator is heated, it flows out of the boiler to the user end.

[0047] As Figure 2a , Figure 2b , Figure 2c , Figure 2d shown, a baffle 23 is arranged in the horizontal steam generator 8. The water vapor entering from the upper header 11 is restricted by the baffle 23 and the shell of the steam generator and flows from bottom to top to the highest point of the steam generator 8, and then exchanges heat with the condensing heat exchange tube 20 from top to bottom. The water in the condensing heat exchange tube 20 enters from the steam generator water inlet 21 and flows upward along the heat exchange tube bundle arranged in a snake shape, and flows out from the steam generator steam outlet 22. After passing through the condensing heat exchange tube 20, the water vapor condenses into water and gathers below the steam generator, and then flows into the upper header 11 and the lower header 2 respectively through the first downcomer 10 and the second downcomer 7; the water in the condensing heat exchange tube 201 flows in the opposite direction to the water vapor to form a full-countercurrent heat exchange. The cross-section of the smooth tubes in the steam generator 8 is in a honeycomb shape, and the distance between adjacent two smooth tubes is the same. The first downcomer 10 can form a sleeve in the rising steam guide pipe 9. The condensed water flows from the first downcomer 10 to the upper header 11, and the steam flows into the steam generator 8 from the interlayer between the rising steam guide pipe 9 and the first downcomer 10.

[0048] As Figure 3a , Figure 3b shown, the inclined steam generator 8 is placed obliquely, and there is an included angle between the inclined steam generator 8 and the horizontal direction. The water vapor from the outlet of the upper header 11 enters the upper part of the inclined steam generator 8 through the rising steam guide pipe 9, and the water vapor exchanges heat with the condensing heat exchange tube 20 from top to bottom. The water in the condensing heat exchange tube 20 enters from the steam generator water inlet 21, and under the action of the tube sheet 24 of the heat exchange tube in the steam generator, it flows into the tube bundle and flows out from the steam generator steam outlet 22. After passing through the condensing heat exchange tube 20, the water vapor condenses into water and gathers at the lower end of the inclined steam generator 8 and flows into the upper header 11 and the lower header 2 respectively through the first downcomer 10 and the second downcomer 7. The water in the condensing heat exchange tube 20 flows in the opposite direction to the water vapor to form a full-countercurrent heat exchange. The cross-section of the tube bundle of the heat exchange tubes in the steam generator is arranged in a honeycomb shape, and the distance between adjacent two tubes is the same.

[0049] As Figure 4a and Figure 4bAs shown in the figure, the V-shaped steam generator includes two inclined cylinders, presenting a V shape. The steam from the upper header outlet enters the upper parts of both ends of the V-shaped steam generator through the rising steam guide pipe 9. The steam exchanges heat with the condensing heat exchange tubes 20 from top to bottom. The water in the condensing heat exchange tubes 20 enters from the steam generator water inlet 21. Under the action of the steam generator heat exchange tube tube sheet 24, it flows into the tube bundle and flows out from the steam generator steam outlet 22. After passing through the condensing heat exchange tubes 20, the steam condenses into water and gathers at the lower end of the V-shaped steam generator, and then flows into the upper header 11 and the lower header 2 through the first downcomer 10 and the second downcomer 7. The water in the condensing heat exchange tubes 20 flows in the opposite direction to the steam, forming a full countercurrent heat exchange. The cross-section of the tube bundle of the heat exchange tubes in the V-shaped steam generator is arranged in a honeycomb shape, and the distance between adjacent two tubes is the same.

[0050] As Figure 5a and 5b shown, in the two-stage steam generator, one section is an inclined cylindrical steam generator, and the other section is a horizontally placed cylindrical steam generator. The steam from the upper header outlet enters the upper part of the two-stage steam generator through the rising steam guide pipe 9. The steam exchanges heat with the condensing heat exchange tubes 20 in the steam generator from top to bottom. The water in the condensing heat exchange tubes enters from the steam generator water inlet 21. Under the action of the steam generator heat exchange tube tube sheet 24, it flows into the tube bundle and flows out from the steam generator steam outlet 22. After passing through the condensing tubes, the steam condenses into water and gathers at the lower end of the two-stage steam generator, and then flows into the upper header 11 and the lower header 2 respectively through the first downcomer 10 and the second downcomer 7. The water in the tubes flows in the opposite direction to the steam, forming a full countercurrent heat exchange. The cross-section of the bare tube bundle in the two-stage steam generator is arranged in a honeycomb shape, and the distance between adjacent two tubes is the same.

[0051] As Figure 6a and Figure 6b shown, the L-shaped steam generator is in the shape of an L. The steam generator is divided into two sections, one section is a vertically placed steam generator, and the other section is a horizontally placed steam generator, which are connected by an arc at both ends. The steam from the upper header outlet enters the upper part of the L-shaped steam generator through the rising steam guide pipe 9. The steam exchanges heat with the condensing heat exchange tubes 20 in the steam generator from top to bottom. The water in the condensing heat exchange tubes 20 enters from the steam generator water inlet 21. Under the action of the steam generator heat exchange tube tube sheet 24, it flows into the tube bundle and flows out from the steam generator steam outlet 22. After passing through the condensing heat exchange tubes 20, the steam condenses into water and gathers at the lower end of the L-shaped steam generator 8, and then flows into the upper header 11 and the lower header 2 respectively through the first downcomer 10 and the second downcomer 7. The water in the tubes flows in the opposite direction to the steam, forming a full countercurrent heat exchange. The cross-section of the bare tube bundle in the L-shaped steam generator is distributed in a diamond shape, and the distance between adjacent two tubes is the same.

[0052] As Figure 7As shown in the figure, a modular steam generator is designed. There are three groups of steam generators 8 arranged above the boiler. The steam in the upper header 11 enters the three groups of steam generators 8 through 9 rising steam pipes 9. The condensed water in the steam generators is respectively sent into the upper header 11 and the lower header 2 through 6 downcomers. The water in the condensing heat exchange pipes flows out from the steam generator water inlet header 26 and the steam generator steam outlet header 25.

[0053] As shown in Figure 8, the steam generator adopts a heat exchange method where water vapor flows inside the tubes. The water vapor enters the steam generator tube bundle 201 from the rising steam pipe 9. Water enters the steam generator through the steam generator water inlet 21, exchanges heat with the water vapor in the condensing heat exchange tubes, and then flows out from the steam generator steam outlet 22 after heat exchange.

[0054] As Figure 9a 、 Figure 9b 、 Figure 9c 、 Figure 9d 、 Figure 9e 、 Figure 9f As shown in the figure, the thickness of each fin 181 of each finned heat exchange tube in the finned heat exchange tube bundle 18 is 2 mm, the distance between the upper and lower fins is 2 mm, and a group of fins is composed of two fins 181 that are left - right mirror - symmetric; among them Figure 9a is a fin with a triangular front part and a rectangular rear part. The triangular fin in the front part and the rectangular fin in the rear part are integrally formed, and the fins on adjacent two finned heat exchange tubes are staggered; among them Figure 9b is a fin with a triangular front part and a rectangular rear part. The fins on adjacent two finned heat exchange tubes are staggered and interspersed; the fin is a curved fin with a flow - disturbing structure, the front part facing the flue gas is curved, and the rear part is rectangular; among them Figure 9c the fin has a curved front part and a rectangular rear part. The front - part fin and the rear - part rectangular fin are integrally formed, and the fins on adjacent two finned heat exchange tubes are staggered and interspersed; among them Figure 9d the fin has a curved front part and a rectangular rear part. The fins on adjacent two finned heat exchange tubes are staggered and interspersed; for the front - wall micro - pore combustion membrane wall, it can be arranged as a finned heat exchange tube, and the curve of the fin 181 runs through the front and back, as Figure 9e is a fin with a curve running through the front and back, and the minimum height is 9 mm, which is beneficial to reducing the temperature of the fin and preventing the fin from overheating; among them Figure 9f is a fin with a spherical flow - disturbing structure added by stamping.

[0055] As Figure 10a and 10bAs shown, the energy-saving condenser 12 is installed at the furnace outlet. The flue gas at the furnace outlet is further utilized in the energy-saving condenser 12. The flue gas outlet of the furnace is connected to the flue gas inlet 32 of the energy-saving condenser. After the flue gas enters the energy-saving condenser 12, it flows into the upper part of the energy-saving condenser 12 along the flue. In the energy-saving condenser 12, the flue gas flows from top to bottom, and the water in the pipeline flows horizontally back and forth from bottom to top, forming a countercurrent heat exchange with the flue gas. The pipelines are arranged in a staggered pattern. After the water in the pipeline is heated, it enters the lower header 2 through the energy-saving condenser outlet. After the flue gas exits from the energy-saving condenser flue gas outlet 31, it enters the air preheater.

[0056] As Figure 11a and Figure 11b As shown, the air preheater flue gas inlet 33 is connected to the energy-saving condenser flue gas outlet 31. The flue gas at the energy-saving condenser outlet is further utilized in the air preheater 14. After the flue gas enters the air preheater 14, the flue gas flows from bottom to top in the air preheater, and the air in the pipeline flows from bottom to top. The pipelines are arranged in a staggered pattern. After the air in the pipeline is heated, it enters the burner distribution head 5 along the flue through the air preheater air outlet 36.

[0057] As shown in Figure 12, the premixed and preheated air and fuel are uniformly mixed in advance before combustion. For a boiler with a fan 15 connected to the air preheater 14, the preheated air enters the burner distribution head 5 from above the burner distribution head 5 through the air duct 16. A fuel inlet 4 is provided on the burner distribution head 5, and the air and fuel are uniformly mixed in the burner distribution head 5; the preheated air enters the burner distribution head from below the burner distribution head 5 through the air duct 16, and a fuel inlet 4 is provided near the burner distribution head 5. After the fuel enters from the fuel inlet, it is uniformly mixed in the burner distribution head; for a boiler with a fan 15 connected to the burner distribution head, the preheated air and fuel are uniformly mixed in the burner distribution head 5, and a fuel inlet 4 is arranged on the burner distribution head 5. The air preheater air outlet 141 is connected to the air duct.

[0058] The above content is only to illustrate the technical idea of the present invention and cannot be used to limit the protection scope of the present invention. Any modification made on the basis of the technical solution according to the technical idea proposed by the present invention falls within the protection scope of the claims of the present invention.

Claims

1. A heat tube type premixed water-cooled tube-to-tube combustion steam generator boiler, characterized in that: The boiler is arranged vertically, comprising a steam generator (8), the steam generator (8) being connected to an upper header (11) via a first downcomer (10) and an ascending air guide pipe (9), the steam generator (8) being connected to a lower header (2) via a second downcomer (7), the upper header (11) and the lower header (2) being connected via left and right membrane water-cooled walls (3), a heat exchange light tube bundle (17), and a fin tube bundle (18); the left and right membrane water-cooled walls (3), the heat exchange light tube bundle (17), and the fin tube bundle (18) The area surrounded by the tube bundle (18) is a furnace; a condensing heat exchange tube (20) is arranged in the steam generator (8), and the condensing heat exchange tube (20) is connected to the water inlet (21) of the steam generator and the steam outlet (22) of the steam generator; an energy-saving condenser (12) is arranged at the rear of the furnace, and the water outlet of the energy-saving condenser (12) is connected to the water inlet (21) of the steam generator; the number and diameter of the first downcomer (10), the ascending air guide tube (9), and the second downcomer (7) are adjusted according to the boiler power.

2. The heat tube type premixed water-cooled tube-to-tube combustion steam generator boiler according to claim 1, characterized in that: A burner distribution head (5) is arranged in front of the heat exchange light tube bundle (17); the area where the burner distribution head (5) covers the heat exchange light tube bundle (17) is the front wall microporous combustion membrane wall (6); the energy-saving condenser (12) is connected to the air preheater (14) and the fan (15) in sequence; the air outlet of the air preheater (14) is connected to the air inlet of the burner distribution head (5) through the air duct (16); and a chimney (13) is arranged above the air preheater (14).

3. The heat tube type premixed water-cooled tube-to-tube combustion steam generator boiler according to claim 2, characterized in that: The front wall microporous combustion membrane wall (6) comprises microporous plates (61) and water-cooled tube bundles (62) arranged alternately and connected to each other; a plurality of micropores (19) are provided on the microporous plates (61); the diameter of the micropores (19) is less than 2.4 mm; the distance between adjacent micropores is greater than 2.5 times the aperture diameter and less than 10 times the aperture diameter; the micropores (19) are arranged in a sequential, staggered or honeycomb arrangement.

4. The heat tube type premixed water-cooled tube-to-tube combustion steam generator boiler according to claim 2, characterized in that: A support (1) is provided at the bottom. The support (1) is made of I-beam. The bases of the lower header (2), the energy-saving condenser (12), the air preheater (14), and the fan (16) are detachably connected to the support (1).

5. The heat tube type premixed water-cooled tube-to-tube combustion steam generator boiler according to claim 1, characterized in that: The cross section of the condensing steam heat exchange tube bundle is honeycomb-shaped, and the distance between two adjacent condensing steam heat exchange tubes is equal.

6. The heat tube type premixed water-cooled tube-to-tube combustion steam generator boiler according to claim 1, characterized in that: The downcomer (10) is arranged on the inner side of the ascending steam duct (9) to form a casing structure. Condensed water flows from the downcomer (10) to the upper header (11), and steam flows from the interlayer between the ascending steam duct (9) and the downcomer (10) into the steam generator (8). The steam generator (8) is arranged horizontally. A baffle (23) is arranged in the steam generator. The baffle (23) is arc-shaped and extends along the inner wall of the steam generator (8). There is a gap between the baffle (23) and the inner wall of the steam generator (8). The gap communicates with the steam from the interlayer between the ascending steam duct (9) and the downcomer (10). Or the steam generator (8) is an inclined steam generator, the ascending steam guide pipe (9) is connected to the upper part of the inclined steam generator, and the interfaces of the downcomer 1 (10) and the downcomer 2 (7) are arranged at the same end of the inclined steam generator; Or the steam generator (8) is a V-shaped steam generator, which includes two inclined cylinders and presents a V shape. The water vapor at the outlet of the upper header enters the upper parts of both ends of the V-shaped steam generator through the ascending steam guide pipe (9). The interfaces of the downcomer 1 (10) and the downcomer 2 (7) are arranged in the middle of the V-shaped steam generator. Or the steam generator (8) is a two-stage steam generator, one of which is an inclined cylindrical steam generator and the other is a horizontal cylindrical steam generator, the steam at the outlet of the upper header enters the upper part of the two-stage steam generator through the ascending steam guide pipe (9), and the interface between the downcomer 1 (10) and the downcomer 2 (7) is arranged at the bottom of the horizontal cylindrical steam generator; Alternatively, the steam generator (8) is an L-shaped steam generator. The L-shaped steam generator is L-shaped and is divided into two sections, one section being a vertically placed steam generator and the other section being a horizontally placed steam generator. The two ends are connected by an arc. The water vapor at the outlet of the upper header enters the upper part of the L-shaped steam generator through the ascending steam guide pipe (9). The interfaces of the downcomer 1 (10) and the downcomer 2 (7) are arranged at the bottom of the horizontally placed steam generator.

7. The heat tube type premixed water-cooled tube-to-tube combustion steam generator boiler according to claim 1, characterized in that: The steam generator adopts a water vapor heat exchange method in the pipe. The ascending steam guide pipe (9) is connected to the upper part of the steam generator, and the downcomer pipe 1 (10) and the downcomer pipe 2 (7) are connected to the lower part of the steam generator. The water vapor enters the steam generator tube bundle from the ascending steam guide pipe (9), and the water enters the shell side of the steam generator through the steam generator water inlet (21), exchanges heat with the water vapor in the condensing steam heat exchange pipe, and flows out from the steam generator steam outlet (22) after the heat exchange.

8. The heat tube type premixed water-cooled tube-to-tube combustion steam generator boiler according to claim 1, characterized in that: A plurality of groups of steam generators (8) are provided, and the plurality of groups of steam generators (8) are arranged obliquely. The lower ends of the steam generators (8) are connected to a steam generator water inlet header (26), and the upper ends of the steam generators (8) are connected to a steam generator steam outlet header (25). Each group of steam generators (8) is connected to an upper header (11) via a plurality of ascending steam guide pipes (9).

9. The heat tube type premixed water-cooled tube-to-tube combustion steam generator boiler according to claim 1, characterized in that: According to the heat exchange amount and the design end difference of the boiler body, the finned heat exchange tube bundle (18) is arranged in one row, two rows or multiple rows; each finned heat exchange tube in the finned heat exchange tube bundle (18) is provided with a fin (181) of a symmetrical structure about a center plane, and the center plane is parallel to the flue gas flow direction; the fin (181) facing the flue gas direction is triangular or curved, and the part away from the flue gas direction is rectangular or curved; the fins on two adjacent finned heat exchange tubes are staggered along the tube axis direction; the fins on two adjacent finned heat exchange tubes are contacted or interlaced; a flow-around structure (27) is provided on the fin (181), and the flow-around structure (27) is a spherical, diamond or triangular protrusion formed by stamping; the thickness of the fin (181) is 0.4 to 4 mm, and the distance between two adjacent fins (181) is 1 mm to 10 mm.

10. The method for operating a heat tube type premixed water-cooled tube-to-tube combustion steam generator boiler according to any one of claims 1 to 9, characterized in that: The premixed gas is ignited and burned on the furnace side of the front wall microporous combustion membrane wall. The flue gas generated by the combustion passes through the light tube bundle (17) and the finned tube bundle (18) in sequence. The light tube bundle (17) and the finned tube bundle (18) are cooled and then enter the energy-saving condenser (12). The flue gas exchanges heat with water in the energy-saving condenser (12). The water heated by the flue gas enters the steam generator (8). The flue gas enters the downstream after further cooling. The water in the lower header (2) is the water condensed in the steam generator (8). The water enters the lower header (2) through the downcomer (7) and is evenly distributed to the light tube bundle (17) and the finned tube bundle (18) in the lower header (2). The tube bundle (18) absorbs heat while flowing upward and vaporizes to become a steam-water mixture, which rises to the upper header (11). The water vapor in the upper header (11) enters the steam generator (8) through the ascending steam guide pipe (9). In the steam generator (8), the water vapor exchanges heat with the condensing heat exchange tube (20). The water vapor outside the condensing heat exchange tube (20) condenses into water and is collected below the steam generator (8). It flows into the upper header (11) and the lower header (2) through the downcomer 1 (10) and the downcomer 2 (7), thereby forming a water self-circulation for the steam generator. After the water in the condensing heat exchange tube (20) is heated, it flows out of the boiler to the user end.

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