Anti-blocking wear-resistant economizer

Abstract

The utility model discloses an anti-blocking wear-resistant coal economizer. The anti-blocking wear-resistant coal economizer comprises a coal economizer inlet flue, a shell and a coal economizer outlet flue which are connected with one another, an inlet header and an outlet header are arranged outside the shell, a plurality of groups of light pipe vertical coiled pipe heating surfaces are arranged in the shell at intervals, a plurality of hanging pieces are fixedly connected to the top of the shell, and each group of light pipe vertical coiled pipe heating surfaces are connected with the plurality of hanging pieces; every two adjacent sets of light pipe vertical coiled pipe heating surfaces are connected through a connecting pipe, an outlet of the light pipe vertical coiled pipe heating surface in the forefront is connected with an outlet header, and an inlet of the light pipe vertical coiled pipe heating surface in the rearmost is connected with an inlet header. An ash bucket is arranged at the lower part of the shell; the utility model not only can effectively prevent dust from accumulating and blocking the circulation cross section, but also enables the whole flow field to be more uniform and the heating surface to be clean, and avoids abrasion and leakage of the heating surface caused by overhigh local flue gas speed, thereby ensuring the long-period normal operation of a unit and reducing the cost.

Description

Technical Field

[0001] The utility model relates to a coal economizer, in particular to an anti-blocking and wear-resistant low-temperature coal economizer for a circulating fluidized bed boiler. Background Art

[0002] As national environmental protection standards continue to improve, boilers have not only added SNCR denitrification devices and SCR devices, but also the consumption of reducing agents has been increasing. As a result, the amount of ammonia escape has also increased. At the same time, many circulating fluidized bed boilers have wet desulfurization installed at the tail. Considering the comprehensive utilization of ash and the impact of desulfurization in the furnace on NOx emissions, the power plant did not add limestone desulfurization in the furnace during operation. Since there is no desulfurization in the furnace, the content of SO2 and SO3 in the flue gas is high. A large amount of escaped ammonia reacts with SO3 to form ammonium bisulfate, and it is easy to deposit and harden in the low-temperature section of the air preheater, which not only affects heat exchange, but also corrodes the heating surface to cause leakage, and the air leakage rate increases. In order to control the air leakage rate, the power plant has to block the leaking pipe group, and the blocking of the heat exchange tubes causes the exhaust gas temperature to be much higher than the design value. When the exhaust gas temperature is high, on the one hand, it endangers the safety of the tail dust removal equipment. On the other hand, a large amount of exhaust gas loss leads to low efficiency of the boiler unit, high coal consumption of the unit, increased desulfurization water consumption, and increased induced draft fan power consumption. In order to improve boiler efficiency, reduce plant power consumption and optimize the system to reduce coal consumption, low-temperature economizers are widely used as an important technical means to save energy and reduce consumption.

[0003] According to the current low-temperature economizer technology survey, the corrosion problem of low-temperature economizer can be solved by wall temperature control and the use of corrosion-resistant materials. However, most of the low-temperature economizers arranged in front of the dust collector are leaking due to wear, which affects the reliability of the low-temperature economizer. In order to reduce the layout space and follow the principle of compact layout, conventional low-temperature economizers usually use finned tubes. Overall, the number of tube rows is dense and the tube gap is relatively narrow, which is very easy to form ash blockage, which in turn causes excessive local flow rate to cause wear and leakage. The leaked working fluid mixes with the smoke and further blocks the heating surface, causing the low-temperature economizer to become calcified and blocked, causing faults such as induced draft fan surge, affecting the safe and stable operation of the equipment, and bringing high maintenance costs to the power plant. Although the low-temperature economizer arranged after the dust collector does not have the problem of wear, it cannot guarantee the safety of the dust collector. Summary of the invention

[0004] The purpose of the utility model is to provide an anti-clogging and wear-resistant economizer in view of the above-mentioned deficiencies in the prior art, which can not only effectively prevent ash accumulation and blockage of the flow cross-section, but also make the entire flow field more uniform and the heating surface cleaner, avoiding wear and leakage of the heating surface due to excessive local flue gas velocity, thereby ensuring the long-term normal operation of the unit and reducing costs.

[0005] In order to achieve the above-mentioned purpose, the utility model provides an anti-blocking and wear-resistant economizer, comprising a connected economizer inlet flue, a shell and an economizer outlet flue; characterized in that: an inlet header and an outlet header are provided outside the shell, and a plurality of groups of bare tube vertical serpentine heating surfaces are provided at intervals inside the shell, a plurality of hangers are fixedly connected to the top of the shell, and each group of bare tube vertical serpentine heating surfaces is connected to a plurality of hangers; two adjacent groups of bare tube vertical serpentine heating surfaces are connected by a connecting pipe, the outlet of the front bare tube vertical serpentine heating surface is connected to the outlet header, and the inlet of the rear bare tube vertical serpentine heating surface is connected to the inlet header; an ash hopper is provided at the lower part of the shell.

[0006] The utility model adopts a countercurrent and sequential arrangement. When in use, condensate at about 70°C enters the inlet header and flows through the heating surfaces of each bare tube vertical serpentine tube in turn to absorb heat, and the final high-temperature condensate is drawn out from the outlet header. The utility model changes the idea of ​​compact arrangement of conventional low-temperature economizers through the array of bare tube vertical serpentine tube heating surfaces arranged at intervals, which can reduce the smoke velocity. In addition, the heating surface tubes adopt bare tubes that are not easy to accumulate dust, and the heating surface adopts a vertical suspension structure as a whole. The heating surface is not easy to accumulate dust. All the dust falling off in the flue gas enters the lower ash hopper and is discharged regularly and centrally, which can effectively prevent dust accumulation and blockage of the flow section, avoid wear and leakage of the heating surface due to excessive local flue gas velocity, and prevent the low-temperature economizer from being blocked by ash and surging of the induced draft fan, thereby ensuring the long-term normal operation of the unit and reducing costs.

[0007] As a further improvement of the utility model, a plurality of guide plates are provided in the inlet flue of the economizer, which can make the entire flow field more uniform, prevent ash accumulation and facilitate heat exchange;

[0008] As a further improvement of the utility model, a soot blower is provided on the front side of the heating surface of each group of vertical serpentine tubes of the light tubes; this can keep the heating surface clean, prevent ash accumulation, and further avoid the heating surface from being worn due to excessive local flue gas velocity;

[0009] As a further improvement of the utility model, the front and rear sides of the heating surface of each group of serpentine tubes are provided with anti-wear tiles, which effectively prevent the heating surface from being worn;

[0010] As a further improvement of the utility model, the upper and lower sides of the front of the heating surface of each group of serpentine tubes are respectively provided with an upper smoke baffle plate and a lower smoke baffle plate fixed to the shell; this can avoid the formation of a smoke corridor in the shell and reduce the smoke velocity;

[0011] As a further improvement of the utility model, the connecting pipes are all arranged outside the shell, and purge pipe joints are provided on each connecting pipe and the inlet header, and each purge pipe joint is connected to a compressed air purge pipe; after shutdown, compressed air is used to purge and remove the water in the heating surface;

[0012] As a further improvement of the utility model, the pitch of the heating surfaces of the two adjacent groups of vertical serpentine tubes of the light tube is greater than 110 mm; a larger pitch can control a lower flue gas velocity and effectively prevent ash accumulation;

[0013] To sum up, the utility model can not only effectively prevent dust accumulation and blockage of the flow section, but also make the entire flow field more uniform and the heating surface cleaner, avoiding wear and leakage of the heating surface due to excessive local flue gas velocity, thereby ensuring the long-term normal operation of the unit and reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is the front view of the embodiment of the utility model.

[0015] Figure 2 for Figure 1 Enlarged view of the upper-middle smoke baffle.

[0016] Figure 3 for Figure 1 Enlarged view of the middle and lower smoke baffle.

[0017] Figure 4 for Figure 1 Enlarged view of the central hanging structure.

[0018] Figure 5 for Figure 4 Left view of . DETAILED DESCRIPTION

[0019] The utility model is further described below in conjunction with the accompanying drawings.

[0020] like Figures 1 to 5As shown, a blockage-proof and wear-resistant economizer of this embodiment comprises an economizer inlet flue 1, a shell 2 and an economizer outlet flue 3 which are connected in sequence, and a plurality of guide plates 5 are arranged in the economizer inlet flue 1 through a bracket 4; an inlet header 6 and an outlet header 7 are arranged outside the shell 2, and four groups of bare tube vertical serpentine tube heating surfaces 8 are arranged at intervals in the shell 2, and a plurality of hanging rings 9 as hanging parts are fixedly connected to the top of the shell 2, and each group of bare tube vertical serpentine tube heating surfaces 8 are connected to a plurality of hanging rings 9; a soot blower 10 is arranged on the front side of each group of bare tube vertical serpentine tube heating surfaces 8, and anti-wear tiles 11 are connected to the front and rear sides of each group of serpentine tube heating surfaces 8, and an upper flue gas flow blocker welded and fixed to the shell is arranged on the upper front side of each group of serpentine tube heating surfaces 8 Plate 12, a support beam 14 is fixedly arranged in the lower part of the shell body, and a lower flue gas baffle 13 welded and fixedly connected to the support beam 14 is arranged on the front lower side of each group of serpentine tube heating surfaces 8; two adjacent groups of light tube vertical serpentine tube heating surfaces 8 are connected by connecting pipes 15, and the pitch of two adjacent groups of light tube vertical serpentine tube heating surfaces 8 is greater than 110mm; the outlet of the frontmost light tube vertical serpentine tube heating surface 8 is connected to the outlet header 7, and the inlet of the rearmost light tube vertical serpentine tube heating surface is connected to the inlet header 6, and the connecting pipes 15 are all arranged outside the shell body 2, and a purge pipe joint 16 is arranged on each connecting pipe 15 and the inlet header 6, and each purge pipe joint 16 is connected to the compressed air purge pipe 17; two ash hoppers 18 are arranged at the lower part of the shell body 2.

[0021] The utility model arranges each group of serpentine tube heating surfaces 8 in a countercurrent and sequential manner. When in use, condensed water at about 70°C enters the inlet header 6 and flows through each light tube vertical serpentine tube heating surface 8 in sequence to absorb heat with the flue gas in the shell 2. Finally, high-temperature condensed water at about 110°C is drawn out from the outlet header 7, and the flue gas temperature is reduced from 170°C to about 120°C. The utility model introduces the flue gas into the shell 2 through several guide plates 5, which can make the entire flow field more uniform, prevent dust accumulation, and facilitate heat exchange. The array of light tube vertical serpentine tube heating surfaces 8 with intervals and enlarged pitches changes the idea of ​​compact layout of conventional low-temperature economizers, and cooperates with the upper flue gas baffle 12 and the lower flue gas baffle 13 to avoid the formation of a flue gas corridor in the shell 2. Both can reduce smoke velocity and reduce pipe wear; the heating surface pipe 8 adopts a light tube that is not easy to accumulate dust, and the heating surface adopts a vertical suspension structure as a whole, so the heating surface is not easy to accumulate dust. All the dust falling off in the flue gas enters the lower ash hopper 18 and is discharged regularly and centrally, which can effectively prevent dust accumulation and blockage of the flow section. The soot blower 10 can keep the heating surface clean and prevent dust accumulation, avoid wear and leakage of the heating surface due to excessive local flue gas velocity, and further prevent the formation of ash blockage in the low-temperature economizer and surging of the induced draft fan, thereby ensuring the long-term normal operation of the unit and reducing costs; the anti-wear tile 11 can effectively prevent the wear of the heating surface; after shutdown, the compressed air purge pipe 17 is passed with compressed air to purge and remove the water in the heating surface 8, which can solve the problem of water drainage and antifreeze;

[0022] The number of the serpentine tube heating surfaces 8 of the utility model can be changed, and the hanging ring 9 as a hanger can also be replaced by a hook; it is illustrated through the above embodiments, but it should be understood that the above embodiments are only for the purpose of example and description, and are not intended to limit the utility model to the scope of the described embodiments.

Claims

1. A blockage-proof and wear-resistant economizer, comprising a connected economizer inlet flue, a shell and an economizer outlet flue; characterized in that: An inlet header and an outlet header are arranged outside the shell, and a plurality of groups of bare tube vertical serpentine tube heating surfaces are arranged at intervals inside the shell. A plurality of hangers are fixedly connected to the top of the shell, and each group of bare tube vertical serpentine tube heating surfaces is connected to a plurality of hangers; two adjacent groups of bare tube vertical serpentine tube heating surfaces are connected through a connecting pipe, and the outlet of the front bare tube vertical serpentine tube heating surface is connected to the outlet header, and the inlet of the rear bare tube vertical serpentine tube heating surface is connected to the inlet header; an ash hopper is arranged at the lower part of the shell.

2. The anti-clogging and wear-resistant economizer according to claim 1, characterized in that: A plurality of guide plates are arranged in the economizer inlet flue.

3. The anti-clogging and wear-resistant economizer according to claim 1 or 2, characterized in that: A soot blower is arranged on the front side of the heating surface of each group of vertical serpentine tubes of the bare tube.

4. The anti-clogging and wear-resistant economizer according to claim 3, characterized in that: The front and rear sides of the heating surface of each group of serpentine tubes are provided with anti-wear tiles.

5. The anti-clogging and wear-resistant economizer according to claim 4, characterized in that: An upper smoke baffle plate and a lower smoke baffle plate fixedly connected to the shell are respectively arranged on the upper and lower sides in front of the heating surface of each group of serpentine tubes.

6. The anti-clogging and wear-resistant economizer according to claim 5, characterized in that: The connecting pipes are all arranged outside the shell, and purge pipe joints are arranged on each connecting pipe and the inlet header, and each purge pipe joint is connected to a compressed air purge pipe.

7. The anti-clogging and wear-resistant economizer according to claim 6, characterized in that: The pitch between the heating surfaces of the two adjacent groups of smooth tube vertical serpentine tubes is greater than 110 mm.

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