阅读说明：本技术 一种可承压式多重水冷预混燃气装置 (Pressure-bearing type multiple water-cooling premixing gas device ) 是由 牛艳青 薛旭峰 王亨通 于 2021-06-09 设计创作，主要内容包括：一种可承压式多重水冷预混燃气装置,包括在燃烧室内设置的多组致密并行布置的平直翅片、翅片管、高U型循环管和低U型循环管,所述最外围的平直翅片上布置进气筒,多组致密并行布置的平直翅片上贯穿设置有翅片管,构成第一重水冷表面；多组致密并行布置的相邻的平直翅片构成多组防回火进气微通道,多组平行布置的翅片管与平直翅片构成流通面积沿进气方向先减缩后渐扩的二次强化防回火进气微通道；翅片管、高U型循环管和低U型循环管的两端分别与套筒式进出水集箱和混合分配集箱相连接,低U型循环管布置构成第二重水冷表面,高U型循环管布置构成第三重水冷表面。本发明结构简单、制造方便,适用于常压锅炉、高压锅炉及超临界锅炉。(A pressure-bearing type multiple water-cooling premixing gas device comprises a plurality of groups of compact parallel arranged flat fins, finned tubes, a high U-shaped circulating tube and a low U-shaped circulating tube, wherein the groups of compact parallel arranged flat fins, the finned tubes, the high U-shaped circulating tube and the low U-shaped circulating tube are arranged in a combustion chamber; a plurality of groups of compact parallel-arranged adjacent flat fins form a plurality of groups of anti-backfire air inlet micro-channels, and a plurality of groups of parallel-arranged finned tubes and the flat fins form a secondary strengthening anti-backfire air inlet micro-channel with the flow area firstly reduced and then gradually enlarged along the air inlet direction; the finned tube, the high U-shaped circulating tube and the low U-shaped circulating tube are connected with the sleeve type water inlet and outlet collecting box and the mixed distribution collecting box at two ends respectively, the low U-shaped circulating tube is arranged to form a second water-cooling surface, and the high U-shaped circulating tube is arranged to form a third water-cooling surface. The invention has simple structure and convenient manufacture, and is suitable for normal pressure boilers, high pressure boilers and supercritical boilers.)

1. A pressure-bearing type multiple water-cooling premixing gas device is characterized by comprising flat fins (2), finned tubes (4), a high U-shaped circulating tube (3a) and a low U-shaped circulating tube (3b) which are arranged in a combustion chamber (1), wherein the flat fins (2) are provided with a plurality of groups and are densely and parallelly arranged, an air inlet cylinder (5) is arranged on the flat fins (2) at the outermost periphery, and the finned tubes (4) penetrate through the flat fins (2) to form a first heavy water-cooling surface; a plurality of groups of compact parallel-arranged adjacent flat fins (2) form a plurality of groups of anti-backfire air inlet micro-channels (6a), and a plurality of groups of parallel-arranged finned tubes (4) and the flat fins (2) form a secondary strengthening anti-backfire air inlet micro-channel (6b) with the flow area firstly reduced and then gradually expanded along the air inlet direction; one end of the finned tube (4) is connected with a sleeve type water inlet and outlet header (7), the other end of the finned tube is connected with a mixed distribution header (8), one end of the high U-shaped circulating tube (3a) is connected with the sleeve type water inlet and outlet header (7), the other end of the high U-shaped circulating tube is connected with the mixed distribution header (8), one end of the low U-shaped circulating tube (3b) is connected with the sleeve type water inlet and outlet header (7), the other end of the low U-shaped circulating tube is connected with the mixed distribution header (8), the low U-shaped circulating tube (3b) is arranged to form a second water-cooling surface, and the high U-shaped circulating tube (3a) is arranged to form a third water-cooling surface.

2. The pressure-bearing type multiple water-cooling premixing gas device of claim 1, characterized in that the high U-shaped circulating pipe (3a) and the low U-shaped circulating pipe (3b) are alternatively distributed in a staggered structure in a concave-convex shape on a horizontal section, and the adjacent high U-shaped circulating pipe (3a) and the adjacent low U-shaped circulating pipe (3b) form a continuous cooling surface in a shape of Chinese character 'shan'.

3. The pressure-bearing type multiple water-cooling premixing gas device of claim 1, characterized in that the high U-shaped circulating pipe (3a) is arranged higher than the low U-shaped circulating pipe (3b) to form a continuous cooling surface in a shape of Chinese character 'shan' which is staggered up and down.

4. The pressure-bearing type multiple water-cooling premixed gas device as claimed in claim 1, wherein the sleeve type water inlet and outlet header tank (7), the mixing distribution header tank (8), the finned tubes (4), the high U-shaped circulating tube (3a) and the low U-shaped circulating tube (3b) form a water circulation system of the cooling device.

5. The pressure-bearing multiple water-cooling premixed gas device as claimed in claim 1, wherein said sleeve-type water inlet and outlet header (7) is provided with a water inlet (9) and a water outlet (10), the outer cylinder of said sleeve-type water inlet and outlet header (7) is a water inlet header (7a), and the inner cylinder is a water outlet header (7 b); the water inlet (9) is arranged at the side of the water inlet header (7a), the combustion chamber (1) is arranged on the outer wall of the water inlet header (7a), and the water inlet header (7a) is connected with the finned tube (4); the water outlet (10) is arranged on the side of the water outlet header (7b), and the water outlet header (7b) is connected with the high U-shaped circulating pipe (3a) and the low U-shaped circulating pipe (3 b).

6. The pressure-bearing type multiple water-cooling premixed gas device as claimed in claim 1, wherein the sleeve type water inlet and outlet header tanks (7), the finned tubes (4), the mixing distribution header tank (8), the high U-shaped circulating tube (3a) and the low U-shaped circulating tube (3b) are all pressure-bearing circular tubes.

Technical Field

The invention relates to the technical field of gas devices, in particular to a pressure-bearing type multiple water-cooling premixing gas device.

Background

The gas boiler is widely applied due to the advantages of high combustion efficiency, low original pollutant emission, low post-treatment technology cost and the like. However, under increasingly stringent emission standards of pollutants, the emission standard of nitrogen oxides in gas boilers in key areas is 150mg/Nm³In some regions even as low as 30mg/Nm³. Because the calorific value of natural gas is very high, the combustion temperature can be up to more than 2000K usually, and when the combustion temperature is higher than 1300 ℃, the reaction speed can be increased by 6-7 times when the temperature is increased by 100 ℃, and the original emission of nitrogen oxides is exponentially increased. Although the low-nitrogen combustion technology of gas-fired boilers at present in China has been developed to a certain extent, such as staged combustion, flue gas recirculation, lean combustion premixing, water-cooling premixing and the like, some technologies still have the defects of high cost, poor effect, inapplicability to high-pressure and supercritical boilers and the like, for example, in patent CN201721339948.5, the adopted upper water chamber and lower water chamber are semicircular pipes with sharp corners, and under the high-pressure operation condition, stress concentration at the sharp corners is easily caused to break the pipes, so that operation safety accidents occur.

Disclosure of Invention

Aiming at the problems of the existing gas burner, the invention aims to provide a pressure-bearing type multiple water-cooling premixing gas device which can realize uniform low-temperature low-NOx surface premixing combustion of gas and is provided with two-stage anti-backfire devices to fully ensure the combustion safety; meanwhile, the gas device can bear high pressure, has simple structure and convenient manufacture, and is suitable for normal pressure boilers, high pressure boilers and supercritical boilers.

In order to achieve the purpose, the invention adopts the technical scheme that:

a pressure-bearing type multiple water-cooling premixing gas device comprises straight fins 2, finned tubes 4, a high U-shaped circulating tube 3a and a low U-shaped circulating tube 3b which are arranged in a combustion chamber 1, wherein the straight fins 2 are provided with multiple groups and are densely arranged in parallel, an air inlet cylinder 5 is arranged on the straight fins 2 on the outermost periphery, and the finned tubes 4 penetrate through the straight fins 2 to form a first heavy water-cooling surface; a plurality of groups of adjacent flat fins 2 form a plurality of groups of anti-backfire air inlet micro-channels 6a, and a plurality of groups of parallel finned tubes 4 and the flat fins 2 form a secondary strengthening anti-backfire air inlet micro-channel 6b with the flow area firstly reduced and then gradually enlarged along the air inlet direction; one end of the finned tube 4 is connected with a sleeve type water inlet and outlet header 7 in a connecting mode, the other end of the finned tube is connected with a mixing distribution header 8, one end of a high U-shaped circulating tube 3a is connected with the sleeve type water inlet and outlet header 7, the other end of the high U-shaped circulating tube is connected with the mixing distribution header 8, one end of a low U-shaped circulating tube 3b is connected with the sleeve type water inlet and outlet header 7, the other end of the low U-shaped circulating tube 3b is connected with the mixing distribution header 8, the low U-shaped circulating tube 3b is arranged to form a second water cooling surface, and the high U-shaped circulating tube 3a is arranged to form a third water cooling surface.

The high U-shaped circulating pipes 3a and the low U-shaped circulating pipes 3b are in an alternately distributed concave-convex staggered structure on the horizontal section, and the adjacent high U-shaped circulating pipes 3a and the adjacent low U-shaped circulating pipes 3b form a continuous cooling surface in a shape of a Chinese character 'shan'.

The high U-shaped circulating pipe 3a is higher than the low U-shaped circulating pipe 3b in arrangement height, and forms a continuous mountain-shaped cooling surface which is staggered up and down.

The sleeve type water inlet and outlet header 7, the mixing distribution header 8, the finned tube 4, the high U-shaped circulating tube 3a and the low U-shaped circulating tube 3b form a water circulating system of the cooling device.

The sleeve type water inlet and outlet header 7 is provided with a water inlet 9 and a water outlet 10, the outer cylinder of the sleeve type water inlet and outlet header 7 is a water inlet header 7a, and the inner cylinder is a water outlet header 7 b; the water inlet 9 is arranged at the side of the water inlet header 7a, the combustion chamber 1 is arranged on the outer wall of the water inlet header 7a, and the water inlet header 7a is connected with the finned tube 4; the water outlet 10 is arranged at the side of the water outlet header 7b, and the water outlet header 7b is connected with the high U-shaped circulating pipe 3a and the low U-shaped circulating pipe 3 b.

The sleeve type water inlet and outlet header 7, the finned tube 4, the mixed distribution header 8, the high U-shaped circulating tube 3a and the low U-shaped circulating tube 3b are all pressure-bearing circular tubes.

The invention has the beneficial effects that:

the multiple water-cooled surfaces are arranged to fully absorb the heat of premixed flame and high-temperature flue gas, so that low-temperature clean combustion is realized; the sleeve type water inlet and outlet header, the mixing distribution header, the finned tube and the high and low U-shaped circulating tubes form a water circulation system of the cooling device.

The finned tubes penetrate through a plurality of groups of compact and parallel-arranged straight fins in a welding mode to form a plurality of groups of parallel-arranged and interconnected ribbed cooling tubes, premixed gas passes through the air inlet cylinder, the anti-backfire air inlet micro-channel and the secondary strengthening anti-backfire air inlet micro-channel and then forms uniform surface combustion on the end faces of the plurality of groups of compact and parallel-arranged straight fins, the rib-shaped structure cuts a thermal boundary layer, the effective heat exchange area is increased, and the optimal heat exchange efficiency and the optimal heat exchange amount are realized. Meanwhile, the high-temperature flue gas and the high and low U-shaped circulating pipes exchange heat further, the turbulence degree of the air flow is increased due to the structural arrangement of the cooling surface in the shape of a Chinese character 'shan', and the low-temperature clean combustion effect is further enhanced.

The multiple groups of flat fins which are densely and parallelly arranged form a tempering-preventing air inlet micro-channel, so that the tempering of premixed flame is prevented; the secondary strengthening anti-backfire air inlet micro-channel is formed by the multiple groups of finned tubes and the straight fins which are arranged in parallel, the flow cross section area of the secondary strengthening anti-backfire air inlet micro-channel is firstly reduced and then increased along the air inlet direction, the premixed flame is further prevented from backfiring, and the combustion safety is fully ensured.

The sleeve type water inlet and outlet header, the finned tubes, the mixing distribution header, the high U-shaped circulating tube and the low U-shaped circulating tube are all pressure-bearing circular tubes and can safely operate in a high-pressure environment; meanwhile, the structure is simple, the manufacturing is easy, and the method is suitable for batch production.

Drawings

FIG. 1 is a partial cross-sectional view of the present invention.

FIG. 2 is a front sectional view of the present invention.

FIG. 3 is a side sectional view of the present invention.

Fig. 4 is a schematic view of the overall structure of the present invention.

FIG. 5 is a schematic view of a sleeve-type water inlet and outlet header according to the present invention.

FIG. 6 is a schematic view of the arrangement of the anti-backfire air inlet micro-channel of the present invention.

FIG. 7 is a schematic view of the secondary strengthening anti-backfire air inlet micro-channel arrangement of the present invention.

Wherein: the device comprises a combustion chamber 1, straight fins 2, a high U-shaped circulating pipe 3a, a low U-shaped circulating pipe 3b, finned pipes 4, an air inlet cylinder 5, an anti-backfire air inlet micro-channel 6a, a secondary strengthening anti-backfire air inlet micro-channel 6b, a sleeve type water inlet and outlet header 7, an inlet header 7a, an outlet header 7b, a mixing distribution header 8, a water inlet 9 and a water outlet 10.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

Referring to fig. 1 to 7, a pressure-bearing multiple water-cooling premixed gas device is specifically connected in the following manner: the air inlet cylinder 5 is arranged on the outermost straight fin 2, the finned tube 4 penetrates through a plurality of groups of straight fins 2 which are densely arranged in parallel, two ends of the finned tube are connected with the sleeve type water inlet and outlet header 7 and the mixing distribution header 8, the adjacent straight fins 2 form a plurality of groups of anti-backfire air inlet micro-channels 6a, the finned tube 4 arranged in parallel and the plurality of groups of straight fins 2 form a secondary reinforced anti-backfire air inlet micro-channel 6b, and the flow area of the secondary reinforced anti-backfire air inlet micro-channel 6b is increased after being reduced along the air inlet direction; the two ends of the high U-shaped circulating pipe 3a and the low U-shaped circulating pipe 3b are respectively connected with a sleeve type water inlet and outlet collecting tank 7 and a mixing distribution collecting tank 8, wherein the high U-shaped circulating pipe 3a is higher than the low U-shaped circulating pipe 3b in arrangement height, so that a continuous 'mountain' -shaped cooling surface which is staggered up and down is formed; the outer cylinder of the sleeve type water inlet and outlet header 7 is a water inlet header 7a, the outer wall of the water inlet header 7a is connected with the combustion chamber 1, a water inlet 9 is arranged and connected with the inlet of the finned tube 4, the inner cylinder is a water outlet header 7b, a water outlet 10 is arranged and connected with the outlets of the high U-shaped circulating tube 3a and the low U-shaped circulating tube 3 b.

For a gas boiler, the generation of nitrogen oxides is mainly classified into a thermal type, a fuel type and a rapid type, and unlike a coal-fired boiler, the generation of the fuel type and the rapid type of nitrogen oxides in the gas boiler is almost negligible, and the thermal type NO is almost negligible_xThe formation of (A) accounts for more than 90% of the total nitrogen oxides. Influence on thermal mode NO_xThe main reasons for the generation include combustion temperature, oxygen concentration, reactant residence time, etc., and the influence of the combustion temperature dominates.

In order to reduce the original emission of nitrogen oxides and ensure that the gas device is suitable for high-pressure working conditions, the invention provides a pressure-bearing type multiple water-cooling premixing gas device, wherein all tubular structures adopt pressure-bearing circular tubes. By means of finned tubes which are evenly arranged at equal intervals and are filled with cooling water and high and low U-shaped circulating tubes which are alternately arranged in a staggered manner, the combustion temperature is fully reduced, the heat exchange efficiency and the combustion safety are ensured, and the low-temperature and low-NO are realized_xUniform surface combustion, and is suitable for normal pressure boiler, high pressure boiler and supercritical boiler. Meanwhile, the cooling device can be used as a cooling device, is applied to the technical field of cooling, and plays a role in fully reducing the temperature of hot air flow and ensuring the safe operation of a heating element.

The working principle of the invention is as follows:

the multiple groups of straight fins 2 are arranged in parallel and compactly at equal intervals to form the anti-backfire air inlet micro-channel 6 a; multiple groups of finned tubes 4 which are arranged in parallel penetrate through the straight fins 2 to form a secondary reinforced anti-backfire air inlet micro-channel 6 b. The mixed gas fuel enters through the uniformly arranged gas inlets, the uniform gas inlet is ensured, the local high temperature in the gas gathering is prevented, meanwhile, the mixed gas fuel with high flow speed, high pressure and high ignition energy is formed by the structural characteristics of the anti-backfire gas inlet micro-channel 6a, the propagation of premixed flame to the gas inlet direction is effectively prevented, meanwhile, the flow cross section area of the secondary reinforced anti-backfire gas inlet micro-channel 6b is reduced firstly and then increased along the gas flow direction, the backfire phenomenon of the premixed flame is further prevented, and the combustion safety is fully ensured. The mixed gas fuel is ignited and combusted on the end faces of a plurality of groups of straight fins 2 which are arranged in parallel, cooling water is filled in the finned tubes 4 to form a first heavy water-cooled surface, the combustion temperature of the root of premixed flame is fully reduced, and the original emission of nitrogen oxides is reduced; meanwhile, the sufficient heat exchange area and heat exchange efficiency are ensured by reasonably arranging the radiating fins of the finned tube 4. The high U-shaped circulating pipe 3a and the low U-shaped circulating pipe 3b are arranged in the combustion chamber 1, the low U-shaped circulating pipe 3b forms a second heavy water-cooling surface, the high U-shaped circulating pipe 3a forms a third heavy water-cooling surface, heat of high-temperature flue gas is fully absorbed, generation of thermal nitrogen oxides in the flue gas is reduced, the low-temperature clean combustion effect is better, meanwhile, due to the continuous structural arrangement of the cooling surface in the shape of a Chinese character 'shan', the turbulence degree of air flow is increased, and the heat exchange effect is further enhanced.

The invention is provided with a sleeve-type water inlet and outlet header 7 and a mixing distribution header 8, wherein the sleeve-type water inlet and outlet header 7 is of an inner sleeve structure and an outer sleeve structure, the sleeve-type water inlet and outlet header 7 is divided into a water inlet header 7a and a water outlet header 7b, cooling water enters the water inlet header 7a through a water inlet 9 and then is introduced into a finned tube 4, and the cooling water is discharged into the mixing distribution header 8 after fully absorbing the heat of premixed flame; the mixing distribution header 8 is connected with inlets of the high U-shaped circulating pipe 3a and the low U-shaped circulating pipe 3b, cooling water after primary heat exchange is introduced into the high U-shaped circulating pipe 3a and the low U-shaped circulating pipe 3b again, secondary heat exchange is formed between the cooling water and high-temperature flue gas, the cooling water is discharged into the water outlet header 7b, and then the cooling water is discharged through the water outlet 10. The secondary heat exchange of the cooling water ensures high-efficiency heat exchange efficiency and economical efficiency of device operation, and meanwhile, all the tubular structures of the invention adopt pressure-bearing circular tubes, can safely operate under high pressure, have simple structure and convenient manufacture, are suitable for batch production and can operate under various working environments.

The specific operation mode of the invention is as follows:

before mixed gas enters the gas device, cooling water is firstly introduced into the water inlet header 7a, after the cooling water is uniformly discharged from the water outlet 10, mixed gas fuel is introduced into the anti-backfire air inlet micro-channel 6a and the secondary reinforced anti-backfire air inlet micro-channel 6b, and finally ignition and combustion are carried out on the end face of the straight fin 2. The flow of the cooling water is flexibly adjusted according to the use requirement in the specific operation process, and then the combustion temperature of the premixed flame can be adjusted.

The above contents are only for explaining the technical idea of the present invention, and the protection scope of the present invention is not limited thereby, and any modifications made on the basis of the technical solution according to the technical idea of the present invention, such as changing the arrangement of the high and low U-shaped circulation pipes, changing the structure of the straight fins into corrugated fins, changing the square burner into the circular burner, etc., fall within the protection scope of the claims of the present invention.