Welded plate heat exchanger for flue gas waste heat recovery

Abstract

The utility model discloses a welding plate heat exchanger for flue gas waste heat recovery of incinerator belongs to industrial waste heat recovery equipment technical field, including heat exchange mechanism and flow pipe mechanism, the heat exchange mechanism includes the board group that is formed by the heat exchange plate body of multiple pieces of stacking welding, has the wide and narrow flow channel for the flue gas circulation and the sheet flow channel for the circulation of heat exchange medium, its lower end is fixed with conical lower end head, flow pipe mechanism detachably fixed in support frame, including first side plate, second side plate and several flow pipe thin tubes, flow pipe thin tube is fixed in first side plate, and the first side plate with the second side plate is through the slide fit of positioning pin and positioning groove. The utility model discloses through wide and narrow flow channel and conical lower end head, effectively solved the flue gas easy jam problem, and simultaneously utilize locking assembly to realize the quick dismounting and reliable sealing of flow pipe mechanism, greatly facilitated the later maintenance.

Description

Technical Field

[0001] This utility model belongs to the technical field of industrial waste heat recovery and high-efficiency heat exchange equipment, and in particular relates to a welded plate heat exchanger for flue gas waste heat recovery in incinerators. Background Technology

[0002] With increasing demands for energy efficiency and environmental protection in industrial production, the recovery and utilization of waste heat generated during industrial processes, especially the residual heat in high-temperature flue gas, has become an important technological direction. In waste incineration and garbage incineration, the flue gas discharged from incinerators has a high temperature and a large amount of heat energy, making it an ideal target for waste heat recovery. Utilizing heat exchangers to recover heat energy from flue gas can not only significantly save fuel costs but also reduce the flue gas emission temperature, which is beneficial for subsequent purification treatment.

[0003] In the application of flue gas waste heat recovery in incinerators, the requirements for heat exchangers are extremely stringent. Incinerator flue gas is characterized by three main features: high temperature, high dust content, and high corrosivity. In particular, the flue gas contains a large amount of fly ash particles and acidic substances that may condense. Traditional shell-and-tube heat exchangers or ordinary plate heat exchangers expose serious structural defects under these harsh conditions. Shell-and-tube heat exchangers have complex structures, with flue gas channels often being large spaces with slow flow velocities. This easily leads to dead zones in the airflow direction and at bends, causing large amounts of fly ash particles to deposit, scale, or even become hard blockages. This rapidly reduces heat exchange efficiency, forcing frequent system shutdowns for cleaning and maintenance, severely impacting production continuity and economic efficiency.

[0004] Meanwhile, due to the harsh operating conditions of incinerators, even with welded, corrosion-resistant heat exchangers, the internal heat exchange components or flow tube systems inevitably require regular inspection, cleaning, or replacement. However, in existing technologies, the flow tube system and the heat exchanger body are mostly rigidly connected by flanges or bolts, resulting in numerous connection points, complex sealing, and extremely time-consuming and complex disassembly and reassembly processes. Especially after operation under high heat loads, component deformation or corrosion further increases the difficulty of disassembly and reassembly, leading to long maintenance cycles and high labor costs, failing to meet the requirements of modern industry for rapid equipment maintenance and high operating rates.

[0005] Therefore, this utility model proposes a welded plate heat exchanger for waste heat recovery of flue gas in incinerators to solve the shortcomings of existing heat exchangers that are prone to clogging when dealing with high dust content flue gas and are difficult to maintain and disassemble later. Utility Model Content

[0006] The purpose of this application is to provide a welded plate heat exchanger for waste heat recovery of flue gas in incinerators, which aims to improve the problems existing in the prior art, such as easy blockage when handling high dust-content flue gas, and the complex connection structure between the flow tube mechanism and the heat exchanger body, which leads to difficulties in later maintenance and disassembly.

[0007] The welded plate heat exchanger for flue gas waste heat recovery in incinerators provided in this application adopts the following technical solution: A welded plate heat exchanger for waste heat recovery from flue gas in an incinerator includes: a support frame and a heat exchange mechanism; The heat exchange mechanism is fixedly connected to the support frame. The heat exchange mechanism includes a plate group formed by stacking and welding multiple heat exchange plate bodies. Wide and narrow flow channels for flue gas and thin plate flow channels for heat exchange medium are formed between the heat exchange plate bodies. A conical lower end is fixedly connected to the lower end of the heat exchange mechanism. The incinerator flue gas waste heat recovery welded plate heat exchanger also includes a flow tube mechanism. The flow tube mechanism is detachably fixed to the support frame, and the flow tube mechanism includes a first side plate, a second side plate, and several flow tube thin tubes; The front end of the thin tube is fixedly connected to the first side plate and extends out of the first side plate toward the heat exchange mechanism. The first side plate and the second side plate are guided by the sliding cooperation of the positioning pin and the positioning groove.

[0008] Preferably, the flow tube mechanism further includes a locking assembly for adjusting the distance between the first side plate and the second side plate. The locking assembly includes a positioning screw, a positioning sleeve, and a rotating ring. The positioning screw is fixedly connected to the second side plate, and the positioning sleeve is threadedly connected to the positioning screw. The rotating ring drives the positioning sleeve to rotate, and one end of the positioning sleeve can abut against the first side plate. By rotating the rotating ring, the positioning sleeve can move along the axial direction of the positioning screw, thereby pushing or releasing the first side plate, so that the front end of the flow tube thin tube forms a detachable sealed connection with the thin plate flow channel interface of the heat exchange mechanism.

[0009] By adopting the above technical solution, a sealed connection was achieved.

[0010] Preferably, the heat exchange plate body has a corrugated structure embossed on its surface, and the bottom of the conical lower head is provided with a drain port for discharging condensate and ash.

[0011] By adopting the above technical solution, the sewage discharge effect was achieved.

[0012] Preferably, the wide and narrow flow channels and the thin plate flow channels are alternately spaced along the stacking direction of the heat exchange plate body within the plate assembly.

[0013] By adopting the above technical solution, the effect of preventing soot adhesion is achieved.

[0014] Preferably, the positioning pin is fixed to either the first side plate or the second side plate, and the positioning groove is formed in the other side plate.

[0015] The above technical solution is used to achieve the desired positioning effect.

[0016] Preferably, the rotating ring is coaxially sleeved on the outer periphery of the positioning sleeve, and the rotating ring and the positioning sleeve rotate synchronously through a key or spline.

[0017] By adopting the above technical solution, the transmission effect is achieved.

[0018] Preferably, the front end of the flow tube is integrally formed or fixedly connected to an annular sealing surface.

[0019] By adopting the above technical solution, a sealing effect is achieved.

[0020] Preferably, the flow tube and the first side plate are connected by welding.

[0021] By adopting the above technical solution, an effective fixation effect can be achieved.

[0022] In summary, this application includes at least the following beneficial technical effects: 1. This utility model solves the problems of existing incinerator flue gas heat exchangers being easily blocked by fly ash and condensate and having short operating cycles by setting wide and narrow flow channels and thin plate flow channels formed by stacking and welding heat exchange plate bodies, and by setting a conical lower end cap at the lower end of the heat exchange mechanism. It achieves active anti-clogging by utilizing the high-speed self-cleaning effect of flue gas and passive sewage and liquid discharge by utilizing gravity collection, thereby ensuring long-term stable and efficient operation of the equipment.

[0023] 2. This utility model solves the problems of difficult disassembly and assembly and time-consuming and labor-intensive maintenance of fluid pipelines in traditional heat exchangers by using a flow tube mechanism consisting of a first side plate, a second side plate, a positioning screw, a positioning sleeve, and a rotating ring. It achieves rapid pressing and sealing or loosening and separation of the thin tube of the flow tube on the first side plate by driving the positioning sleeve to move axially along the screw by rotating the rotating ring, which greatly simplifies the difficulty of on-site maintenance and shortens the downtime.

[0024] 3. This utility model solves the problem of easy deflection and sealing failure in the disassembly mechanism during docking by setting a sliding fit structure of positioning pin and positioning groove between the first side plate and the second side plate, and making the front end of the thin tube of the flow tube have an annular sealing surface. It ensures that the first side plate is stably guided during disassembly and assembly, and that the thin tube of the flow tube is accurately aligned with the interface of the heat exchange mechanism, and finally achieves reliable high-pressure sealing and prevents medium leakage. Attached Figure Description

[0025] Figure 1 This is a perspective view of the welded plate heat exchanger for recovering waste heat from flue gas in an incinerator, as proposed in this utility model. Figure 2This is a schematic diagram of the heat exchanger plate body of the welded plate heat exchanger for waste heat recovery of flue gas in an incinerator proposed in this utility model. Figure 3 for Figure 2 Enlarged view of point A in the image; Figure 4 This is a schematic diagram of the thin-plate flow channel of the welded plate heat exchanger for waste heat recovery of flue gas in an incinerator proposed in this utility model. Figure 5 This is a magnified view of point B in the diagram; Figure 6 This is a schematic diagram of the flow tube mechanism of the welded plate heat exchanger for flue gas waste heat recovery in incinerators proposed in this utility model.

[0026] Explanation of reference numerals in the attached drawings: 1. Support frame; 2. Heat exchange mechanism; 201. Heat exchange plate body; 202. Wide and narrow flow channels; 203. Thin plate flow channel; 204. Conical lower end cap; 3. Flow tube mechanism; 301. Flow tube thin tube; 302. Positioning screw; 303. Positioning sleeve; 304. Rotating ring; 305. First side plate; 306. Positioning pin; 307. Second side plate; 308. Positioning groove. Detailed Implementation

[0027] The following is in conjunction with the appendix Figure 1 - Appendix Figure 6 This application will be described in further detail below.

[0028] Reference Figures 1-6 The present invention provides an embodiment of a welded plate heat exchanger for waste heat recovery of flue gas in an incinerator, comprising a support frame 1, a heat exchange mechanism 2 fixedly connected to the support frame 1, and a flow tube mechanism 3 detachably fixed to the support frame 1. The support frame 1 provides an installation reference and structural support for the heat exchange mechanism 2 and the flow tube mechanism 3. The heat exchange mechanism 2 is used to realize the heat exchange between high-temperature flue gas and heat exchange medium, and the flow tube mechanism 3 is used to introduce or export the heat exchange medium into or out of the heat exchange mechanism 2. The heat exchange mechanism 2 includes a plate assembly consisting of multiple stacked heat exchange plate bodies 201 welded together. The heat exchange plate bodies 201 are sealed together by welding, forming independent wide and narrow flow channels 202 for flue gas flow and thin plate flow channels 203 for heat exchange medium flow. The wide and narrow flow channels 202 and the thin plate flow channels 203 are alternately arranged within the plate assembly along the stacking direction of the heat exchange plate bodies 201. The flue gas and the heat exchange medium flow in pure countercurrent or crossflow mode within their respective flow channels. The surface of the heat exchange plate body 201 is imprinted with a wave pattern. The corrugated structure increases turbulence when flue gas flows through the wide and narrow flow channels 202. Combined with the narrow flow channel design, the flue gas passes through at a higher velocity, thereby generating a self-cleaning effect and reducing fly ash deposition. The lower end of the heat exchange mechanism 2 is fixedly connected to a conical lower end cap 204. The structure of the conical lower end cap 204 facilitates the collection of condensed liquid and a small amount of ash residue during the flue gas cooling process by gravity. A drain port for discharging condensate and ash residue is provided at the bottom of the conical lower end cap 204, further ensuring the unobstructed flow inside the flow channel. The flow tube mechanism 3 includes a first side plate 305, a second side plate 307, and several flow tube thin tubes 301; The front end of the flow tube thin tube 301 is fixedly connected to the first side plate 305. In one specific embodiment, the flow tube thin tube 301 and the first side plate 305 are welded together, and the front end of the flow tube thin tube 301 extends out of the side of the first side plate 305 facing the heat exchange mechanism 2. To achieve a reliable seal, the front end of the thin tube 301 is integrally formed or fixedly connected with an annular sealing surface, which is used to abut against the interface of the thin plate flow channel 203 of the heat exchange mechanism 2. A guide structure is provided between the first side plate 305 and the second side plate 307 of the flow tube mechanism 3. The guide structure includes a positioning pin 306 and a positioning groove 308. The first side plate 305 and the second side plate 307 are guided by the sliding cooperation of the positioning pin 306 and the positioning groove 308, so as to ensure that the first side plate 305 moves smoothly toward or away from the heat exchange mechanism 2. The positioning pin 306 is fixed to either the first side plate 305 or the second side plate 307, while the positioning groove 308 is opened in the other side plate. The positioning pin 306 is fixed to the first side plate 305, and the positioning groove 308 is opened in the second side plate 307. The flow tube mechanism 3 is also provided with a locking component for adjusting the distance between the first side plate 305 and the second side plate 307. The locking assembly includes a positioning screw 302 fixedly connected to the second side plate 307, a positioning sleeve 303 threadedly connected to the positioning screw 302, and a rotating ring 304 that drives the positioning sleeve 303 to rotate. The positioning sleeve 303 is disposed between the first side plate 305 and the second side plate 307, and the end of the positioning sleeve 303 facing the first side plate 305 can abut against the outer surface of the first side plate 305. When the rotating ring 304 is rotated, the rotating ring 304 drives the positioning sleeve 303 to rotate on the positioning screw 302 and undergo axial displacement, thereby pushing or releasing the first side plate 305, realizing the rapid pressing and sealing or loosening and separation between the annular sealing surface at the front end of the thin tube 301 and the interface of the thin plate flow channel 203 of the heat exchange mechanism 2. The plate surface of the heat exchange plate body 201 is imprinted with a corrugated structure, which is used to induce turbulence when the fluid flows through it to enhance the heat transfer efficiency; and, the wide and narrow flow channels 202 The thin plate flow channel 203 is alternately arranged in the plate group along the stacking direction of the heat exchange plate body 201. This structure allows the hot and cold fluids to flow alternately in their respective channels, achieving efficient heat transfer. At the same time, a drain port for discharging condensate and ash is provided at the bottom of the conical lower end cap 204. The drain port is located at the lowest point of the conical structure, which facilitates the complete drainage of deposits. The positioning pin 306 is fixed to either the first side plate 305 or the second side plate 307, while the positioning groove 308 is opened in the other. Figure 3 The embodiment shown in the figure has a positioning pin 306 fixedly connected to the first side plate 305, and a positioning groove 308 opened on the second side plate 307, with the two slidingly engaged. In order to ensure that the rotating ring 304 can reliably drive the positioning sleeve 303 to rotate synchronously, the rotating ring 304 is coaxially sleeved on the outer circumference of the positioning sleeve 303, and the rotating ring 304 and the positioning sleeve 303 are synchronously rotated through a key or spline. When the operator applies torque to the rotating ring 304, the torque is transmitted to the positioning sleeve 303 through the key or spline structure. As a preferred embodiment of the sealing and connection structure of the convection tube mechanism 3, the front end of the thin tube 301 of the convection tube is integrally formed or fixedly connected with an annular sealing surface. The annular sealing surface provides a flat and strong contact surface for forming a high-pressure seal with the thin plate flow channel 203 interface of the heat exchange mechanism 2. Furthermore, the thin tube 301 of the convection tube is welded to the first side plate 305. This fixing method ensures high structural strength and eliminates the possibility of leakage.

[0029] Working principle: During heat recovery, high-temperature flue gas enters from the inlet of heat exchange mechanism 2 and flows through the wide and narrow channels 202 in the plate assembly. The heat exchange medium is introduced through the thin tube 301 of the flow tube mechanism 3 and enters the thin plate channel 203 of heat exchange mechanism 2. The corrugated structure imprinted on the plate surface of heat exchange plate body 201 causes strong turbulence to be formed in both flue gas and heat exchange medium in their respective channels. At the same time, the narrow design of the wide and narrow channels 202 ensures the high flow velocity of flue gas. The combination of turbulence and high flow velocity produces a self-cleaning effect on the surface of heat exchange plate body 201, preventing soot adhesion. The high-temperature flue gas transfers heat to the heat exchange medium in the thin plate channel 203 through heat exchange plate body 201. After cooling, the flue gas, under the action of gravity, carries condensate and a small amount of ash and slag to the conical lower end head 204 at the lower end of heat exchange mechanism 2 and is discharged through the drain port at the bottom of conical lower end head 204. When maintenance or disassembly of the flow tube mechanism 3 is required, the operator rotates the rotating ring 304. The rotating ring 304 drives the positioning sleeve 303 to rotate in the opposite direction on the positioning screw 302 fixedly connected to the second side plate 307 via a key or spline. Since the positioning sleeve 303 and the positioning screw 302 are connected by a thread, the positioning sleeve 303 will move backward along the axial direction of the positioning screw 302 while rotating, releasing the abutment force on the first side plate 305. At this time, under the guidance of the positioning pin 306 and the positioning groove 308, the first side plate 305, together with the flow tube thin tube 301 fixedly connected to the first side plate 305, can move backward smoothly, so that the annular sealing surface at the front end of the flow tube thin tube 301 separates from the thin plate flow channel 203 interface of the heat exchange mechanism 2, thereby realizing the quick disassembly of the flow tube mechanism 3. When installing the flow tube mechanism 3, the flow tube mechanism 3 is pushed to the predetermined position by the guide of the positioning pin 306 and the positioning groove 308. Then, the rotating ring 304 is rotated in the forward direction. The rotating ring 304 drives the positioning sleeve 303 to rotate on the positioning screw 302 and move forward along the axial direction. One end of the positioning sleeve 303 moves forward to abut and push the first side plate 305. The first side plate 305 moves forward under force, and finally the annular sealing surface of the front end of the flow tube 301 fixedly connected to the first side plate 305 abuts tightly against the interface of the thin plate flow channel 203 of the heat exchange mechanism 2, forming a reliable sealing connection.

Claims

1. A welded plate heat exchanger for flue gas waste heat recovery in incinerators, including: The support frame (1) and the heat exchange mechanism (2) are fixedly connected to the support frame (1). The heat exchange mechanism (2) includes a plate group formed by stacking and welding multiple heat exchange plate bodies (201). Wide and narrow flow channels (202) for flue gas and thin plate flow channels (203) for heat exchange medium are formed between the heat exchange plate bodies (201). A conical lower end cap (204) is fixedly connected to the lower end of the heat exchange mechanism (2). The feature is that it also includes a flow tube mechanism (3). The flow tube mechanism (3) is detachably fixed to the support frame (1). The flow tube mechanism (3) includes a first side plate (305), a second side plate (307), and several flow tube thin tubes (301). The front end of the flow tube thin tube (301) is fixedly connected to the first side plate (305) and extends out of the first side plate (305) towards the heat exchange mechanism (2). The first side plate (305) and the second side plate (307) are guided by the sliding cooperation of the positioning pin (306) and the positioning groove (308).

2. The incinerator flue gas waste heat recovery welded plate heat exchanger according to claim 1, characterized in that: The flow tube mechanism (3) is also provided with a locking assembly for adjusting the distance between the first side plate (305) and the second side plate (307). The locking assembly includes a positioning screw (302), a positioning sleeve (303), and a rotating ring (304). The positioning screw (302) is fixedly connected to the second side plate (307). The positioning sleeve (303) is threadedly connected to the positioning screw (302). The rotating ring (304) drives the positioning sleeve (303) to rotate. One end of the positioning sleeve (303) can abut against the first side plate (305). By rotating the rotating ring (304), the positioning sleeve (303) can move along the axial direction of the positioning screw (302), thereby pushing or releasing the first side plate (305) so that the front end of the flow tube thin tube (301) and the thin plate flow channel (203) interface of the heat exchange mechanism (2) form a detachable sealed connection.

3. The incinerator flue gas waste heat recovery welded plate heat exchanger according to claim 1, characterized in that: The heat exchange plate body (201) has a corrugated structure embossed on its surface, and the bottom of the conical lower end cap (204) is provided with a drain port for discharging condensate and ash.

4. The incinerator flue gas waste heat recovery welded plate heat exchanger according to claim 1, characterized in that: The wide and narrow flow channels (202) and the thin plate flow channels (203) are alternately spaced within the plate group along the stacking direction of the heat exchange plate body (201).

5. The incinerator flue gas waste heat recovery welded plate heat exchanger according to claim 1, characterized in that: The positioning pin (306) is fixed to either the first side plate (305) or the second side plate (307), and the positioning groove (308) is formed in the other.

6. The incinerator flue gas waste heat recovery welded plate heat exchanger according to claim 2, characterized in that: The rotating ring (304) is coaxially sleeved on the outer periphery of the positioning sleeve (303), and the rotating ring (304) and the positioning sleeve (303) rotate synchronously through a key or spline.

7. The incinerator flue gas waste heat recovery welded plate heat exchanger according to claim 1, characterized in that: The front end of the flow tube thin tube (301) is integrally formed or fixedly connected with an annular sealing surface.

8. The incinerator flue gas waste heat recovery welded plate heat exchanger according to claim 1, characterized in that: The flow tube thin tube (301) and the first side plate (305) are welded together.

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