Modularized countercurrent heat exchange plate type air pre-heater

Abstract

The utility model aims to disclose a modularized countercurrent heat exchange plate type air pre-heater which comprises a plate type heat exchange unit, the plate type heat exchange unit comprises at least one layer of heat exchange module and flow guide modules, and the flow guide modules are arranged on the upper layer and the lower layer of the heat exchange module respectively. The flow guide module arranged on the upper layer of the heat exchange module is connected with a smoke inlet connector and an air outlet connector, and the flow guide module arranged on the lower layer of the heat exchange module is connected with a smoke outlet connector and an air inlet connector. Compared with the prior art, the defects that a rotary air pre-heater is blocked and an all-welded plate type air pre-heater can only exchange heat in a cross flow mode are overcome when the flue gas flow is large, the dust containing rate is high and substances prone to bonding are contained, the plate distance can be flexibly adjusted through the height of the protruding points, the air pre-heater is suitable for large-flow flue gas, blocking is avoided, and the service life of the air pre-heater is prolonged. Countercurrent flow heat exchange of the whole air pre-heater is achieved due to the existence of the flow guide strips, the end difference of the air pre-heater is small, the heat exchange efficiency of the air pre-heater is greatly improved, and the purpose of the air pre-heater is achieved.

Description

Technical Field

[0001] The utility model relates to a heat exchange plate type air preheater, in particular to a modular countercurrent heat exchange plate type air preheater suitable for boiler flue gas waste heat recovery and energy-saving equipment. Background Art

[0002] The air preheater is a heat exchange device that uses the waste heat from boiler exhaust to heat the air required for combustion.

[0003] At present, there are three main types of air preheaters: rotary, tubular and fully welded plate. The rotary air preheater has a high heat transfer surface density of 500m 2 / m 3 ; Lightweight, the thinnest heat storage plate thickness can reach 0.5mm; reasonable layout scheme, countercurrent heat exchange and other advantages, are widely used in 600MW and above coal-fired power generation units.

[0004] With the vigorous development of photovoltaic and wind power, it has become an inevitable trend for thermal power units to participate in deep peak regulation. During deep peak regulation, the boiler flue gas temperature decreases, and the ammonia escape caused by uneven ammonia injection in the denitrification facilities increases. Ammonium bisulfate is precipitated in large quantities in the low-temperature section of the rotary air preheater. Ammonium bisulfate is liquid when the temperature is lower than 200°C and has high viscosity. After it adheres to the surface of the heat storage element, it combines with the fly ash in the flue gas to cause flow blockage.

[0005] Tubular air preheaters are mainly used for coal-fired power generation units of 200MW and below and various industrial boilers. They can withstand very high pressures and temperatures, but they have problems such as low heat exchange efficiency, easy clogging, and large size that makes them difficult to flexibly arrange. Fully welded plate air preheaters have high heat exchange efficiency, but when the air volume is large, only cross-flow heat exchange can be used, which limits the heat transfer end difference between high-temperature flue gas and low-temperature air, and the cross-flow heat exchange method is not easy to deploy in a power plant environment.

[0006] Therefore, there is a particular need for a modular countercurrent heat exchange plate air preheater to solve the above-mentioned existing problems. Utility Model Content

[0007] The purpose of the utility model is to propose a modular countercurrent heat exchange plate air preheater, which overcomes the problems existing in the prior art, is suitable for large-flow flue gas, does not cause blockage, and greatly improves the heat exchange efficiency of the air preheater.

[0008] The technical problem solved by the present invention can be achieved by adopting the following technical solutions:

[0009] A modular countercurrent heat exchange plate air preheater comprises a plate heat exchange unit, the plate heat exchange unit comprises at least one layer of heat exchange module and flow guide module, the upper layer and the lower layer of the heat exchange module are respectively provided with flow guide modules, the flow guide module arranged on the upper layer of the heat exchange module is connected with a smoke inlet joint and an air outlet joint, the flow guide module arranged on the lower layer of the heat exchange module is connected with a smoke outlet joint and an air inlet joint; the heat exchange module comprises a heat exchange shell and a heat exchange core, the heat exchange core is composed of a stack of double-sided convex point plates, and the double-sided convex point plates are arranged with a flue gas outlet joint and an air inlet joint; The protruding points on the smoke side and the protruding points on the air side, the protruding points on the smoke side of the adjacent double-sided protruding plates are opposite to form a smoke channel, and the protruding points on the air side of the adjacent double-sided protruding plates are opposite to form an air channel; the guide module includes a guide shell and a guide core, the guide core is composed of double-sided micro-convex plates and guide strips, the height of the guide strips is the same as the height of the protrusions of the double-sided protruding plates of the heat exchange core, the guide strips include inlet guide strips and transition guide strips, the inlet guide strips and the transition guide strips are respectively arranged on both sides of the double-sided micro-convex plates.

[0010] In a preferred embodiment of the present invention, the heat exchange module and the flow guide module are fixedly connected to each other by bolts.

[0011] In a preferred embodiment of the utility model, four rectangular notches are cut out at the four corners of the double-sided convex point plate, respectively, and the notches are matched with the size of the supporting square tube of the heat exchange shell by the mold profiling technology.

[0012] In a preferred embodiment of the present invention, the height of the bumps of the double-sided bump plate is 3-10 mm.

[0013] In a preferred embodiment of the present invention, the number of layers of the heat exchange module is 1-5.

[0014] In a preferred embodiment of the present invention, the number of guide bars of the guide module is 3-10.

[0015] In a preferred embodiment of the utility model, four rectangular notches are cut out at the four corners of the double-sided micro-convex plate, respectively, and the mold-forming technology is used to ensure that the notches match the size of the supporting square tube of the guide shell.

[0016] In a preferred embodiment of the present invention, sealing edge strips are arranged on the cross sections of the fluid inlet and the fluid outlet of the flow guiding module to ensure that the two fluids are not mixed.

[0017] Compared with the prior art, the modular countercurrent heat exchange plate air preheater of the utility model overcomes the shortcomings of clogging of the rotary air preheater and cross-flow heat exchange of the fully welded plate air preheater when the flue gas flow is large, the dust content is high, and the flue gas contains easily sticky materials. The plate spacing can be flexibly adjusted through the height of the convex points, which is suitable for large-flow flue gas without clogging. The presence of the guide strip realizes countercurrent heat exchange of the entire air preheater, makes the end difference of the air preheater very small, greatly improves the heat exchange efficiency of the air preheater, and achieves the purpose of the utility model.

[0018] 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

[0019] Figure 1 It is a structural schematic diagram of a modular countercurrent heat exchange plate-type air preheater of the utility model;

[0020] Figure 2 It is a structural schematic diagram of the heat exchange module of the utility model;

[0021] Figure 3 It is a structural schematic diagram of the flow diversion module of the utility model;

[0022] Figure 4 It is a structural schematic diagram of a double-sided convex point board of the utility model;

[0023] Figure 5 It is a structural schematic diagram of the double-sided micro-convex plate inlet flow guide of the utility model;

[0024] Figure 6 It is a structural schematic diagram of the double-sided micro-convex plate transfer and diversion of the utility model;

[0025] Figure 7 It is a structural schematic diagram of the flow of cold and hot fluids of the utility model.

[0026] Figure numbers: 11- flow guide module, 12- heat exchange module, 21- flue gas inlet joint, 22- flue gas outlet joint, 23- air inlet joint, 24- air outlet joint, 31- supporting square tube, 32- heat exchange core, 33- bolt hole, 41- flow guide shell, 42- flow guide core, 43- sealing edge strip, 51- rectangular notch, 52- flue gas side convex point, 53- air side convex point, 61- double-sided micro-convex point structure, 62- inlet guide strip, 63- transfer guide strip. DETAILED DESCRIPTION

[0027] 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.

[0028] The modular countercurrent heat exchange air preheater of the utility model comprises a plate heat exchange unit; the plate heat exchange unit comprises a heat exchange module 12 and a flow guide module 11, the heat exchange module 12 comprises a heat exchange shell and a heat exchange core 32, the flow guide module comprises a flow guide shell 41 and a flow guide core 42; the flue gas inlet joint 21 and the air outlet joint 24 are connected to the flow guide module 11 arranged on the upper layer of the heat exchange module 12, and the flue gas outlet joint 22 and the air inlet joint 23 are connected to the flow guide module 11 arranged on the lower layer of the heat exchange module 12 The heat exchange module 12 and the flow guide module 11 are connected by bolts; the upper and lower layers of the heat exchange module 12 are respectively provided with the flow guide module 11, the heat exchange module 12 can be arranged in a single layer or multiple layers, and the heat exchange core 32 is composed of a stack of double-sided convex point plates, and the double-sided convex point plates are arranged with convex points protruding toward the flue gas side and protruding toward the air side. The flue gas side convex points 52 of the adjacent double-sided convex point plates are opposite to form a flue gas channel, and the air side convex points 53 of the adjacent double-sided convex point plates are opposite to form an air channel. The convex point structure not only plays a supporting role, but also plays a supporting role. The double-sided convex plate has four rectangular notches 51 cut out at the four corners, and the size of the supporting square tube 31 of the heat exchange shell is ensured to be exactly matched by the mold technology; the guide module 11 is located at the top and bottom layers of the air preheater, and only one layer is arranged respectively. The guide core is composed of double-sided micro-convex plates and guide strips. The double-sided micro-convex structure 61 of the double-sided micro-convex plate is used to enhance heat transfer. The existence of the guide strip realizes the countercurrent heat exchange of the entire air preheater. The height of the guide strip is equal to the heat exchange The height of the convex points of the double-sided convex point plate in the heat core, the guide strips include an inlet guide strip 62 and a transfer guide strip 63, which are respectively arranged on both sides of the same double-sided micro-convex plate to achieve uniform flow of the fluid in the guide module and the heat exchange module. Four rectangular notches are cut out at the four corners of the double-sided micro-convex plate, and the mold-forming technology is used to ensure that the size of the supporting square tube of the guide shell is exactly the same; sealing edge strips 43 are arranged on the cross-section of the fluid inlet and fluid outlet of the guide module 11 to ensure that the two fluids will not mix.

[0029] Example:

[0030] Reference Figure 1 The high-temperature flue gas flows in from the flue gas inlet joint 21, and flows out from the flue gas outlet joint 22 after passing through the plate heat exchange unit. The flue gas temperature decreases. The low-temperature air flows in from the air inlet joint 23, and flows out from the air outlet joint 24 after passing through the plate heat exchange unit. The air temperature increases. The plate heat exchange unit includes a heat exchange module 12 and a flow guide module 11. All modules participate in heat exchange and are connected by bolts to achieve the detachability of the joints, which is helpful for the transportation, installation and maintenance of the air preheater.

[0031] Reference Figure 2 and Figure 4The double-sided convex point plate is exactly the same size as the heat exchange shell of the heat exchange module. The modeling technology is used to ensure that the sizes of all heat exchange modules and flow guide modules are consistent, and the modules are docked to ensure that the two fluids are not mixed.

[0032] Reference Figure 3 , Figure 5 and Figure 6 The guide core of the guide module is composed of a double-sided micro-convex plate and guide strips. The guide strips include an inlet guide strip 62 and a transfer guide strip 63. The inlet guide strip 62 and the transfer guide strip 63 are respectively located on both sides of a double-sided micro-convex plate.

[0033] Reference Figure 7 The high-temperature flue gas enters from the upper guide module, passes through the upper transfer guide module, and evenly passes through the lower heat exchange module, and then passes through the lower transfer guide module to flow out through the lower outlet guide module; at the same time, the low-temperature air enters from the lower guide module, passes through the lower transfer guide module, and evenly passes through the upper heat exchange module, and then passes through the upper transfer guide module to flow out through the upper outlet guide module; so as to realize the countercurrent heat exchange between the high-temperature flue gas and the low-temperature air in the modular plate air preheater.

[0034] 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 modular countercurrent heat exchange plate air preheater, characterized in that: The plate heat exchange unit comprises a heat exchange module and a flow guide module of at least one layer, wherein the upper layer and the lower layer of the heat exchange module are respectively provided with flow guide modules, wherein the flow guide module provided on the upper layer of the heat exchange module is connected with a smoke inlet joint and an air outlet joint, and the flow guide module provided on the lower layer of the heat exchange module is connected with a smoke outlet joint and an air inlet joint; the heat exchange module comprises a heat exchange shell and a heat exchange core, wherein the heat exchange core is composed of a stack of double-sided convex point plates, and the double-sided convex point plates are provided with convex points protruding toward the smoke side. points and convex points protruding toward the air side, the convex points on the smoke side of adjacent double-sided convex point plates are opposite to form a smoke channel, and the convex points on the air side of adjacent double-sided convex point plates are opposite to form an air channel; the guide module includes a guide shell and a guide core, the guide core is composed of double-sided micro-convex plates and guide strips, the height of the guide strips is the same as the height of the convex points of the double-sided convex point plates of the heat exchange core, the guide strips include inlet guide strips and transition guide strips, and the inlet guide strips and the transition guide strips are respectively arranged on both sides of the double-sided micro-convex plates.

2. The modular countercurrent heat exchange plate air preheater according to claim 1, characterized in that: The heat exchange module and the flow guide module are fixedly connected to each other by bolts.

3. The modular countercurrent heat exchange plate air preheater according to claim 1, characterized in that: Four rectangular notches are cut out at the four corners of the double-sided convex point plate, respectively, and the notches are matched with the size of the supporting square tube of the heat exchange shell by the mold-forming technology.

4. The modular countercurrent heat exchange plate air preheater according to claim 1, characterized in that: The height of the bumps of the double-sided bump plate is 3-10 mm.

5. The modular countercurrent heat exchange plate air preheater according to claim 1, characterized in that: The number of layers of the heat exchange module is 1-5.

6. The modular countercurrent heat exchange plate air preheater according to claim 1, characterized in that: The number of guide bars of the guide module is 3-10.

7. The modular countercurrent heat exchange plate air preheater according to claim 1, characterized in that: Four rectangular notches are cut out at the four corners of the double-sided micro-convex plate, respectively, and the notches are ensured to match the size of the supporting square tube of the guide shell through the mold-forming technology.

8. The modular countercurrent heat exchange plate air preheater according to claim 1, characterized in that: Sealing edge strips are arranged on the cross sections of the fluid inlet and the fluid outlet of the flow guiding module.

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