Efficient power station plate type air heater

Abstract

The utility model discloses an efficient power station plate type air heater. A plate piece bag is arranged in an air duct shell; the plate piece bag is formed by arranging a plurality of sets of heat exchange plate pieces up and down, each set of heat exchange plate pieces comprises a first plate piece and a second plate piece which are connected with each other, the left side and the right side of the back face of the second plate piece are connected with the left side and the right side of the back face of the first plate piece in a sealed mode, and an air channel is formed in the front-back direction of the first plate piece and the second plate piece. And the back surface of the second plate in one group of heat exchange plates is hermetically connected with the front and rear side ends of the front surface of the first plate in the other adjacent group of heat exchange plates, the left and right side parts are hermetically connected, and left and right communicated water channels are formed on the left and right sides. The problems that an existing air heater is large in heat exchange end difference, low in efficiency, large in size, large in resistance, prone to blockage and the like can be solved, and the cost performance of a heat exchanger is greatly improved.

Description

Technical Field

[0001] The utility model relates to a power station air preheater. Background Art

[0002] In the existing industrial system of our country, thermal power plants are an indispensable and important component. In order to better burn and effectively protect the safe operation of the air preheater from being blocked, people preheat the primary and secondary air for boiler combustion to prevent the air preheater from condensing and blocking. The existing primary and secondary air heaters are mostly finned tube heaters, and their heating medium is steam extracted from the steam turbine, with relatively high quality. Since the heating temperature of the primary and secondary air is mostly within 80 degrees, while the temperature of the steam extracted from the steam turbine is mostly between 200 - 400 degrees, which does not conform to the principle of energy gradient utilization. In recent years, many power plants use flue gas waste heat to heat water, and then use the water to heat the primary and secondary air. The type of air preheater used is still a finned tube heat exchanger. Due to the limitations of the finned tube type, problems such as low heat transfer coefficient, large wind resistance, difficult to clean, and high cost are caused. Perhaps when using a steam heater to heat the primary and secondary air, the finned tube heater is a reasonable type, but when using water to heat the primary and secondary air for heat exchange, it is obvious that the plate heat exchanger is more energy-saving and cost-effective.

[0003] Therefore, it is necessary to further improve the existing technology. Summary of the Invention

[0004] The purpose of the utility model is to provide an efficient power station plate air preheater that can solve problems such as large heat transfer end difference, low efficiency, large volume, large resistance, and easy blockage of the existing air preheater, and greatly improve the cost performance of the heat exchanger.

[0005] The technical solution of the utility model is as follows:

[0006] An efficient power station plate air preheater, including an air duct housing, characterized in that: a plate pack is arranged in the air duct housing; the plate pack is composed of multiple groups of heat exchange plates arranged vertically. Each group of heat exchange plates includes a first plate and a second plate, the first plate and the second plate are connected to each other, the left and right sides of the back of the second plate are hermetically connected to the left and right sides of the back of the first plate, and an air duct is formed in the front and back directions of the first plate and the second plate; the back of the second plate in a group of heat exchange plates is hermetically connected to the front side, rear side ends, and partially hermetically connected to the left and right sides of the first plate in an adjacent group of heat exchange plates, and water channels that communicate with each other left and right are formed on the left and right sides.

[0007] Cold air enters from one end inside the air duct housing, i.e., the air inlet, passes through the plate pack and is heated, then flows out from the other end of the air duct housing, i.e., the air outlet. The cold air is heated into hot air. On the side of the air duct housing that is radially perpendicular to the flow direction of the cold and hot air in the air duct (the upper and lower sides or the left and right sides of the rectangular air duct housing), there are a water inlet header and a water outlet header. The hot liquid used to heat the cold air enters from the water inlet header, flows through the water channels between the plates, releases heat to the adjacent air flow channels, and then flows out from the water outlet header.

[0008] Relatively convex or concave bumps or recesses or convex or concave corrugations are provided on the first plate and the second plate. The bumps, recesses or convex and concave corrugations on the first plate and the second plate support each other, increasing the strength, and at the same time increasing the turbulence and heat transfer effect.

[0009] A sealing device is provided at the adjacent or contacting part of the water inlet header or the water outlet header and the plate pack to ensure that the liquid does not leak into the cold and hot air sides and the non-working gap between the air duct housing and the plate pack.

[0010] Protrusions are provided on the left and right sides of the front surface of the second plate, and grooves are provided on the left and right sides of the back surface of the first plate to cooperate with the protrusions on the back surface of the second plate. A sealing gasket is provided in the grooves to make the back surface of the first plate and the front surface of the second plate be sealed and cooperate on the left and right sides. At the same time, an air duct is formed in the front and back directions of the first plate and the second plate. Protrusions are provided around the front surface of the first plate, and a groove is provided on the outer periphery of the second plate. A sealing gasket is provided in part of the groove on the outer periphery of the second plate, and there is no sealing gasket in part of the grooves on the left and right sides of the second plate. When the groove on the back surface of the second plate in a group of heat exchange plates is sealed and cooperates with the protrusion on the front surface of the first plate in an adjacent group of heat exchange plates, water channels that communicate with each other left and right are formed on the left and right sides.

[0011] The left and right sides of the back surface of the second plate and the left and right sides of the back surface of the first plate are sealed and connected by a welding seal form; the back surface of the second plate in a group of heat exchange plates and the front surface of the first plate in an adjacent group of heat exchange plates are partially sealed and connected by a welding connection.

[0012] The high-efficiency power plant plate-type air heater of the present utility model has the following beneficial effects compared with the prior art:

[0013] 1. The high-efficiency power plant plate-type air heater of the present utility model can achieve the function of maximizing the increase of the air temperature. Since the hot fluid is close to countercurrent with the air, its heating effect is better than that of the existing finned tube heat exchanger with cross-flow heat transfer.

[0014] 2. The corrugations on the plates in the present utility model greatly increase the heat transfer efficiency between air and water. At the same time, the air flow channel has a smaller resistance because it does not have the complex shape of finned tubes, and it is more difficult to be deliberately blocked. Even if it is blocked, it is easier to clean.

[0015] 3. Compared with the traditional finned tube method, the utility model has the characteristics of small floor area, more heat regeneration (small temperature difference), and less water storage in use, and is especially suitable for the transformation project of changing steam-gas to water-gas and the heat exchange project with small temperature difference. Brief Description of the Drawings

[0016] The present utility model will be further described below in conjunction with the drawings and embodiments.

[0017] Figure 1 It is a schematic structural view of an embodiment of the present utility model.

[0018] Figure 2 It is Figure 1 View A of

[0019] Figure 3 It is Figure 1 View B of

[0020] Figure 4 It is a schematic front view of the first plate.

[0021] Figure 5 It is a schematic back view of the first plate.

[0022] Figure 6 It is a schematic front view of the second plate.

[0023] Figure 7 It is a schematic back view of the second plate. Detailed Embodiment

[0024] An efficient power plant plate type air heater includes an air duct housing 1, and a plate pack 2 is arranged inside the air duct housing; the plate pack is composed of multiple groups of heat exchange plates arranged vertically, and each group of heat exchange plates includes a first plate 3 and a second plate 4. The first plate and the second plate are connected to each other. The left and right sides of the back of the second plate are hermetically connected to the left and right sides of the back of the first plate. An air duct is formed in the front and back directions of the first plate and the second plate; the back of the second plate in a group of heat exchange plates is hermetically connected to the front and back ends and partially hermetically connected to the left and right sides of the front of the first plate in an adjacent group of heat exchange plates, and water channels communicating with each other left and right are formed on the left and right sides.

[0025] Cold air enters from one end inside the air duct housing, that is, from the air inlet, passes through the plate pack and is heated, and then flows out from the other end of the air duct housing, that is, the air outlet. The cold air is heated into hot air; on the side of the air duct housing perpendicular to the radial direction of the cold and hot air flow in the air duct (the upper and lower sides or the left and right sides of the rectangular air duct housing), a water inlet header 5 and a water outlet header 6 are provided. The hot liquid for heating the cold air enters from the water inlet header, flows through the water channels between the plates, releases heat to the adjacent air flow channels, and flows out from the water outlet header.

[0026] On the first plate and the second plate, there are relatively raised bump points or raised corrugations 7. The bump points or raised corrugations on the first plate and the second plate support each other, increasing the strength and at the same time increasing the turbulence and heat exchange effect. The bump points and raised corrugations can also be concave or concave corrugations.

[0027] At the high points of the header for inlet and outlet water, there are outlets for non-condensable gases, and at the low points, there are drain ports.

[0028] In the air duct housing, there is a support structural member 8 for supporting the plate pack, and a sealing structure for sealing the gap between the plate pack and the air duct housing, preventing hot and cold air from entering the gap between the air duct housing and the plate pack, and also preventing the working medium on the other side from entering the hot and cold air side.

[0029] At the adjacent or contacting part of the inlet header or outlet header and the plate pack, there is a sealing device to ensure that the liquid does not leak into the hot and cold air side and the non-working gap between the air duct housing and the plate pack.

[0030] On the left and right sides of the front surface of the second plate, there are raised portions 9. On the left and right sides of the back surface of the first plate, there are grooves 10 that cooperate with the raised portions on the back surface of the second plate. A sealing gasket 11 is arranged in the grooves, so that the back surface of the first plate and the front surface of the second plate are sealed and matched on the left and right sides. At the same time, there is no seal in the front and back directions of the first plate and the second plate, forming an air duct. On the periphery of the front surface of the first plate, there are raised portions 12, and on the outer periphery of the second plate, there are grooves 13. In some parts of the grooves on the outer periphery of the second plate, there are sealing gaskets 14. In some parts or all of the grooves on the left and right sides of the second plate, there is no sealing gasket in the form of 15 and 16. When the back surface groove of the second plate in a group of heat exchange plates is sealed and matched with the front surface raised portion of the first plate in an adjacent group of heat exchange plates, water channels that communicate with each other left and right are formed on the left and right sides.

[0031] A pressing plate can be used on the outside of the plate pack including multiple combinations of the first plate and the second plate. The size of the pressing plate depends on the size of the plate pack and can be split or integral.

[0032] The present utility model can also adopt the following form:

[0033] The left and right sides of the back surface of the second plate and the left and right sides of the back surface of the first plate are sealed and connected by a welding seal form. The back surface of the second plate in a group of heat exchange plates and the front surface of the first plate in an adjacent group of heat exchange plates are partially sealed and connected by a welding connection. When welding is used, the raised portions 9, grooves 10, sealing gaskets 11, raised portions 12, grooves 13, sealing gaskets 14, etc. do not need to be prefabricated and used, and the corresponding sealing edges of the first and second plates can be directly welded.

[0034] Along the cold air direction, multiple plate packs can be connected in series. Along the cold air cross-section direction, multiple plate packs can be arranged in parallel. The inlet water tank and the outlet water tank can correspond to the number of plate packs. They can be arranged on the same side, the opposite side, or even on different sides. When using welding, the grooves, protrusions, rubber pads, etc. of components 10, 11, 12, 12, and 14 do not need to be prefabricated and used. The corresponding sealing edges of the first and second plates can be directly welded.

[0035] Although the inlet and outlet water headers are rigidly connected to the air duct housing, inside they are connected to the plate packs to inject or discharge liquid into or from the plate packs.

[0036] The sizes of the inlet and outlet water tanks in the figure are only for illustration. Their height can be the same as the height of the plates. Their width can be a part of the plate pack (in the direction of the total thickness of the first plate + the second plate), and their width can be a part or all of the plate pack (in the length direction of the first plate or the second plate). Of course, other appropriate adjustments can also be made.

Claims

1. A high-efficiency power station plate-type air heater, comprising an air duct housing, characterized in that: The plate package is arranged in the air duct housing; the plate package is composed of a plurality of groups of heat exchange plates arranged up and down, each group of heat exchange plates includes a first plate and a second plate, the first plate and the second plate are in surface contact with each other, the left and right sides of the back of the second plate are sealed and connected with the left and right sides of the back of the first plate, and the front and rear directions of the first plate and the second plate form an air duct; the back of the second plate in one group of heat exchange plates is sealed and connected with the front and rear side ends of the first plate in another adjacent group of heat exchange plates, and is partially sealed and connected with the left and right sides, and a water channel communicating left and right is formed on the left and right sides; Cold air enters from one end of the air duct shell, namely the air inlet, passes through the plate package to be heated, and then flows out from the other end of the air duct shell, namely the air outlet, and the cold air is heated to hot air; on the side of the air duct shell that is perpendicular to the radial direction of the cold and hot air flow in the air duct, a water inlet header and a water outlet header are provided, and the hot liquid used to heat the cold air enters from the water inlet header, flows through the water channel between the plates, releases heat with the adjacent air flow channel, and flows out from the water outlet header; The first plate and the second plate are provided with relatively convex or concave convex points or concave points or convex or concave corrugations. The convex points, concave points or convex and concave corrugations on the first plate and the second plate support each other to increase strength, while increasing turbulence and heat exchange effects.

2. The high-efficiency panel heater for power stations according to claim 1 is characterized in that: In the air duct shell, a supporting structure is provided for supporting the plate package, and a sealing structure is provided for sealing the gap between the plate package and the air duct shell, so as to prevent cold and hot air from entering the gap between the air duct shell and the plate package, and also prevent the working medium on the other side from entering the cold and hot air side.

3. A high-efficiency power station plate-type air heater according to claim 1 or 2, characterized in that: Protrusions are arranged on the left and right sides of the front side of the second plate, and grooves are arranged on the left and right sides of the back side of the first plate to match the protrusions on the back side of the second plate. Sealing pads are arranged in the grooves, so that the back side of the first plate and the front side of the second plate are sealed and matched on the left and right sides, and at the same time, air ducts are formed in the front and rear directions of the first plate and the second plate; protrusions are arranged around the front side of the first plate, and grooves are arranged on the outer periphery of the second plate, and sealing pads are partially arranged in the grooves on the outer periphery of the second plate, and there is no sealing pad in part of the grooves on the left and right sides of the second plate, so that when the grooves on the back side of the second plate in one group of heat exchange plates are sealed and matched with the protrusions on the front side of the first plate in another adjacent group of heat exchange plates, water channels communicating left and right are formed on the left and right sides.

4. A high-efficiency power station plate-type air heater according to claim 1 or 2, characterized in that: The left and right sides of the back side of the second plate are sealed and connected to the left and right sides of the back side of the first plate by welding; the back side of the second plate in one group of heat exchange plates is sealed and connected to the front side of the first plate in another adjacent group of heat exchange plates by welding.

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