Plate type low-temperature economizer for coal-fired power plant

Abstract

The utility model aims at disclosing a plate-type low-temperature economizer for a coal-fired power plant, which comprises an economizer shell and a plate-type heat exchange core body, the plate-type heat exchange core body is arranged in the economizer shell, compared with the prior art, the plate-type low-temperature economizer does not contain fins, all heat exchange areas are in one-time heat exchange, and the heat exchange efficiency is high; the plate sheets used by the corrugated plate bundle are small in thickness, so that the weight of the plate-type low-temperature economizer is reduced; the distance between the flue gas channels can be designed according to the flue gas working condition, and blockage is not prone to occurring; and the windward area is small, the erosive wear of the corrugated plate bundle is reduced, the service life of the plate type low-temperature economizer is prolonged, and the aim of the utility model is fulfilled.

Description

Technical Field

[0001] The utility model relates to a plate-type low-temperature economizer, in particular to a plate-type low-temperature economizer for a coal-fired power plant suitable for boiler flue gas waste heat recovery and energy-saving equipment. Background Art

[0002] With the proposal of the goals of "carbon peak" and "carbon neutrality", new energy power generation methods represented by wind power generation and photovoltaic power generation have achieved rapid development. The connection of new energy to the grid has increased the peak-to-valley difference of the power grid load, and wind power and photovoltaic power generation have the characteristics of randomness and indirectness. Therefore, the participation of coal-fired power generation units in deep peak regulation has become an inevitable trend. When coal-fired power generation units participate in deep peak regulation, the uneven ammonia injection in the denitrification process is further aggravated, and the ammonium bisulfate produced is liquefied and precipitated in the low-temperature economizer. The liquid ammonium bisulfate has a high viscosity and combines with the dust in the flue gas to cause the low-temperature economizer to be blocked. At the same time, the emergence of flue gas corridors has aggravated the wear of the low-temperature economizer.

[0003] At present, low-temperature economizers in coal-fired power plants mainly use H-type finned tubes. The presence of fins increases the flue gas resistance, making it very easy for ammonium bisulfate to precipitate between the fins, causing blockage in the flow channel. At the same time, the finned tubes are very prone to wear and bursting under the scouring of high-velocity flue gas, resulting in the service life of the finned tube type low-temperature economizer being far lower than the design value, generally less than three years.

[0004] Therefore, there is a particular need for a plate-type low-temperature economizer for a coal-fired power plant to solve the above-mentioned existing problems. Utility Model Content

[0005] The utility model aims to provide a plate-type low-temperature economizer for a coal-fired power plant, which overcomes the problems existing in the prior art, has high heat exchange efficiency, is not prone to clogging, and prolongs the service life of the plate-type low-temperature economizer.

[0006] The technical problem solved by the present invention can be achieved by adopting the following technical solutions:

[0007] A plate-type low-temperature economizer for a coal-fired power plant comprises an economizer shell and a plate-type heat exchange core, the plate-type heat exchange core is arranged inside the economizer shell, the left end face of the economizer shell is connected to the flue gas inlet joint, the right end face of the economizer shell is connected to the flue gas outlet joint, and the upper end face and the lower end face of the economizer shell are sealed by a steel plate; the plate-type heat exchange core is formed by stacking a plurality of corrugated plate bundles, the corrugated plate bundle is formed by laser welding of two stainless steel plates, sealing welds for sealing are arranged around the corrugated plate bundle, a guide welding line for guiding flow and a spoiler welding point for spoiling flow are arranged in the middle of the corrugated plate bundle, a condensate inlet pipe and a condensate outlet pipe are welded on one end face of the corrugated plate bundle, the condensate inlet pipes of all the corrugated plate bundles are connected to the condensate inlet header, the condensate outlet pipes of all the corrugated plate bundles are connected to the condensate outlet header, the corrugated plate bundles constitute a condensate flow channel, and the channel between the two corrugated plate bundles constitutes a flue gas flow channel.

[0008] In a preferred embodiment of the present invention, the welded corrugated plate bundle is expanded by high-pressure gas.

[0009] In a preferred embodiment of the present invention, the number of the flow-guiding welding lines of the corrugated plate bundle is 3-12.

[0010] In a preferred embodiment of the present invention, the corrugation protrusion height of the corrugated plate bundle is 5-15 mm.

[0011] In a preferred embodiment of the present invention, the spacing between the smoke channels is 10-40 mm.

[0012] Compared with the prior art, the plate-type low-temperature economizer for a coal-fired power plant of the utility model does not contain fins, and all heat exchange areas are used for one-time heat exchange, with high heat exchange efficiency; the thickness of the plates used in the corrugated plate bundle is small, which reduces the weight of the plate-type low-temperature economizer; the spacing of the flue gas channels can be designed according to the flue gas working conditions, and is not prone to blockage; the windward area is small, which reduces the scouring and wear of the corrugated plate bundle, and increases the service life of the plate-type low-temperature economizer, thereby achieving the purpose of the utility model.

[0013] The features of the present invention can be clearly understood by referring to the drawings and the following detailed description of the preferred embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of a plate-type low-temperature economizer of the utility model;

[0015] Figure 2 It is a structural schematic diagram of the spoiler welding point plate bundle of the utility model;

[0016] Figure 3 It is a structural schematic diagram of the cross section of the spoiler welding point plate bundle of the utility model;

[0017] Figure 4 It is a structural schematic diagram of the spoiler welding wire plate bundle of the utility model;

[0018] Figure 5 It is a structural schematic diagram of the cross section of the spoiler welding wire plate bundle of the utility model.

[0019] Explanation of the accompanying numbers: 1-plate heat exchange core, 2-economizer shell, 3-1-flue gas inlet joint, 3-2-flue gas outlet joint, 4-1-condensate inlet header, 4-2-condensate outlet header, 1-1-sealing weld, 1-2-flow guide weld, 1-3-spoiler weld, 1-4-condensate inlet pipe, 1-5-condensate outlet pipe, 1-6-welding point plate bundle corrugation, 5-spoiler weld plate bundle, 5-1-spoiler weld, 5-2-welding wire plate bundle corrugation. DETAILED DESCRIPTION

[0020] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further described below with reference to specific illustrations.

[0021] The utility model discloses a plate-type low-temperature economizer for a coal-fired power plant, comprising a plate-type heat exchange core 1, an economizer shell 2, a condensate inlet header 41, a condensate outlet header 42, a flue gas inlet joint 31 and a flue gas outlet joint 32; the plate-type heat exchange core 1 is arranged inside the economizer shell 2, the left end face of the economizer shell 2 is connected to the flue gas inlet joint 31, the right end face of the economizer shell 2 is connected to the flue gas outlet joint 32, and the upper end face and the lower end face of the economizer shell 2 are sealed with steel plates.

[0022] The plate heat exchange core 1 is formed by stacking a number of corrugated plate bundles, which are formed by laser welding of two stainless steel plates. Sealing welds 11 are arranged around the corrugated plate bundle, and a guide weld line 12 for guiding and a spoiler weld point 13 for spoiling are arranged in the middle of the corrugated plate bundle. The corrugated plate bundle can also adopt a spoiler weld line plate bundle 5, and a spoiler weld line 51 is used on the spoiler weld line plate bundle 5 instead of the spoiler weld point 13. A condensate inlet pipe 14 and a condensate outlet pipe 15 are welded on one side end face of the corrugated plate bundle. The welded corrugated plate bundle is expanded by high-pressure gas; the condensate inlet pipes 14 of all corrugated plate bundles are connected to the condensate inlet header 41, and the condensate outlet pipes 15 of all corrugated plate bundles are connected to the condensate outlet header 42. The corrugated plate bundle constitutes a condensate flow channel, and the channel between the two corrugated plate bundles constitutes a flue gas flow channel.

[0023] Example:

[0024] Reference Figure 1, high-temperature flue gas flows in from the flue gas inlet joint 31, flows out from the flue gas outlet joint 32 after passing through the plate heat exchange core 1, and the flue gas temperature decreases, low-temperature condensed water flows in from the condensed water inlet header 41, flows out from the condensed water outlet header 42 after passing through the plate heat exchange core 1, and the condensed water temperature increases. An economizer shell 2 is installed outside the plate heat exchange core 1 to fix the plate heat exchange core 1. The economizer shell 2 and the flue gas inlet joint 31 and the flue gas outlet joint 32 are sealed by welding to achieve zero leakage of the heat exchange medium to the environment. They can also be connected by bolts to achieve detachable joints, which is helpful for the transportation, installation and maintenance of the economizer.

[0025] Reference Figure 2 The condensate flows in from the condensate inlet pipe 14, and under the action of the guide welding line 12, flows through the entire heat exchange plate bundle in sequence and then flows out from the condensate outlet pipe 15. The spoiler welding point 13 plays a role in enhancing the condensate spoiler and strengthening the mechanical strength of the plate bundle.

[0026] Reference Figure 3 The corrugation of the plate bundle at the welding point plays a role in enhancing the smoke turbulence and strengthening the heat exchange.

[0027] Reference Figure 4 The corrugated plate bundle can also be in the form of a spoiler weld wire plate bundle 5, with spoiler weld wires 52 replacing spoiler weld points 13, which is suitable for working conditions requiring lower condensate flow resistance.

[0028] The above shows and describes the basic principle and main features of the utility model and the advantages of the utility model. Those skilled in the art should understand that the utility model is not limited by the above embodiments, and the above embodiments and descriptions are only for explaining the principle of the utility model. Without departing from the spirit and scope of the utility model, the utility model may have various changes and improvements, which fall within the scope of the utility model to be protected, and the scope of protection of the utility model is defined by the attached claims and their equivalents.

Claims

1. A plate-type low-temperature economizer for a coal-fired power plant, characterized in that: It includes an economizer shell and a plate heat exchange core, the plate heat exchange core is arranged inside the economizer shell, the left end face of the economizer shell is connected to the flue gas inlet joint, the right end face of the economizer shell is connected to the flue gas outlet joint, the upper end face and the lower end face of the economizer shell are sealed by a steel plate; the plate heat exchange core is formed by stacking a plurality of corrugated plate bundles, the corrugated plate bundle is formed by laser welding of two stainless steel plates, sealing welds for sealing are arranged around the corrugated plate bundle, flow guide welding lines for guiding and flow spoiler welding points for spoiler are arranged in the middle of the corrugated plate bundle, a condensate inlet pipe and a condensate outlet pipe are welded on one end face of the corrugated plate bundle, the condensate inlet pipes of all the corrugated plate bundles are connected to the condensate inlet header, the condensate outlet pipes of all the corrugated plate bundles are connected to the condensate outlet header, the corrugated plate bundle constitutes a condensate flow channel, and the channel between the two corrugated plate bundles constitutes a flue gas flow channel.

2. The plate-type low-temperature economizer for a coal-fired power plant according to claim 1, characterized in that: The welded corrugated plate bundle is expanded by high-pressure gas.

3. The plate-type low-temperature economizer for a coal-fired power plant according to claim 1, characterized in that: The number of the guide welding lines of the corrugated plate bundle is 3-12.

4. The plate-type low-temperature economizer for a coal-fired power plant according to claim 1, characterized in that: The corrugation protrusion height of the corrugated plate bundle is 5-15 mm.

5. The plate-type low-temperature economizer for a coal-fired power plant according to claim 1, characterized in that: The spacing between the flue gas flow channels is 10-40 mm.

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