Non-metal shell and tube type gas-gas heat exchanger

Abstract

The invention discloses a non-metal shell and tube type gas-gas heat exchanger, which belongs to the technical field of energy conservation and environmental protection, and comprises a GGH body, a GGH tube pass high-temperature side reducing section is arranged at the top of the GGH body, a GGH tube pass low-temperature side reducing section is arranged at the bottom of the GGH body, and a GGH shell side baffling smoke box is arranged on one side of the GGH body. A GGH shell side high-temperature side variable-diameter section is arranged at the top of the side, away from the GGH shell side baffling smoke box, of the GGH body, a GGH shell side low-temperature side variable-diameter section is arranged at the bottom of the side, away from the GGH shell side baffling smoke box, of the GGH body, a sequentially-arranged pipe bundle is arranged in the GGH body, an upper pipe plate is fixedly connected to the top of the sequentially-arranged pipe bundle, and a plurality of pipe bundle positioning nets are arranged on the sequentially-arranged pipe bundle at equal intervals. And the downstream tube bundle is made of fluoroplastic materials. The fluoroplastic has excellent corrosion resistance and can effectively resist strong corrosive substances in waste incineration flue gas, the GGH body is arranged between the deacidification equipment and the denitration equipment, and the deacidified low-temperature flue gas is heated by using the denitrated high-temperature flue gas, so that part of energy consumption can be effectively saved.

Description

Technical Field

[0001] This invention belongs to the field of energy-saving and environmental protection technology, and in particular relates to a non-metallic tubular gas-to-gas heat exchanger. Background Technology

[0002] GGH, short for Gas Gas Heat, can be understood as a flue gas-to-flue gas heat exchanger. It is widely used in waste incineration and hazardous waste treatment projects, primarily utilizing the heat from high-temperature, unpurified flue gas to heat the low-temperature purified flue gas after wet acid removal. The main purpose is to use waste heat to increase the flue gas temperature, saving energy consumption such as fuel gas and steam. Currently, the industrial sector has an ever-increasing demand for energy conservation, emission reduction, and waste heat recovery. Traditional heat exchangers, when facing complex operating conditions, especially highly corrosive flue gas environments, suffer from problems such as short lifespan, high maintenance costs, and low heat exchange efficiency. Summary of the Invention

[0003] The purpose of this invention is to provide a non-metallic tubular gas-to-gas heat exchanger to solve the problems existing in the prior art.

[0004] To achieve the above objectives, the present invention provides the following solution: The present invention provides a non-metallic tubular gas-to-gas heat exchanger, including a GGH body. The top of the GGH body is provided with a high-temperature side variable diameter section of the GGH tubes, and the bottom of the GGH body is provided with a low-temperature side variable diameter section of the GGH tubes. One side of the GGH body is provided with a GGH shell-side baffle smoke box. The top of the side of the GGH body away from the GGH shell-side baffle smoke box is provided with a GGH shell-side high-temperature side variable diameter section, and the bottom of the side of the GGH body away from the GGH shell-side baffle smoke box is provided with a GGH shell-side low-temperature side variable diameter section. A parallel tube bundle is provided inside the GGH body. An upper tube sheet is fixedly connected to the top of the parallel tube bundle. Multiple tube bundle positioning nets are provided at equal intervals on the parallel tube bundle. A baffle plate is provided in the middle of the parallel tube bundle and is fixedly connected to the inner wall of the GGH body. A breather plate is provided at the bottom of the parallel tube bundle. The parallel tube bundle is made of fluoroplastic material.

[0005] Preferably, the parallel tube bundle is composed of multiple single tube bundles, each single tube bundle including a heat exchange tube, the top of which is provided with an expansion pin, and the bottom of which is provided with a sealing tube ring.

[0006] Preferably, the heat exchange tube is made of fusible polytetrafluoroethylene fluoroplastic, the diameter of the heat exchange tube is 40mm-60mm, and the wall thickness of the heat exchange tube is 1mm-1.5mm.

[0007] Preferably, the upper tube sheet includes a tube sheet body, an upper skin is provided outside the tube sheet body, a lower skin is provided at the bottom of the tube sheet body, the upper skin is fixedly connected to the lower skin, and the upper skin is fixedly connected to the heat exchange tube.

[0008] Preferably, the tube sheet body is provided with a plurality of parallel tube holes at equal intervals, the heat exchange tubes are provided in the parallel tube holes, and the edge of the tube sheet body is provided with a plurality of bolt holes at equal intervals.

[0009] Preferably, the tube bundle positioning net has double-finned tubes on both sides, the tube bundle positioning net includes multiple hexagonal rings, the heat exchange tubes are arranged inside the hexagonal rings, and two hexagonal rings located in the horizontal position are connected by a limiting rod.

[0010] Preferably, the hexagonal ring has asymmetrical positioning holes on both sides, the limiting rod includes a steel wire, the steel wire is fitted with a positioning sleeve, the two ends of the steel wire are respectively threaded with solid hooks, the solid hooks are fitted with pins, the tail of the pin is provided with an opening, and the opening is connected to a pin ring.

[0011] Preferably, the baffle plate is provided with a plurality of baffle holes at equal intervals, and the heat exchange tube is provided in the baffle holes, with the baffle holes and the heat exchange tube being clearance-fitted.

[0012] Preferably, the breathing plate is provided with a plurality of heat exchange tube holes at equal intervals, and the heat exchange tubes are provided in the heat exchange tube holes.

[0013] Preferably, the outer diameter of the expansion pin is smaller than the inner diameter of the heat exchange tube, and the inner diameter of the sealing ring is larger than the outer diameter of the heat exchange tube.

[0014] This invention discloses the following technical effects: After acid removal, the flue gas enters the lower half of the GGH body through the high-temperature side variable-diameter section on the shell side, where heat exchange occurs. After passing through the GGH shell-side baffle flue, it exchanges heat again with the upper half of the GGH body, increasing the flue gas temperature. The flue gas then enters the flue gas reheat device, where it continues to heat up with additional energy input. The denitrified high-temperature flue gas enters the GGH body tube side through the high-temperature side variable-diameter section on the tube side, releasing heat, and is discharged from the low-temperature side variable-diameter section on the tube side. The flue gas is then led to the chimney for emission.

[0015] The in-line tube bundle is made of fluoroplastic material, which has excellent corrosion resistance and can effectively resist strong corrosive substances in waste incineration flue gas, such as sulfur dioxide and hydrogen chloride, to achieve zero corrosion and zero leakage. The heat exchange tube has a certain degree of flexibility, good surface smoothness, strong self-cleaning ability, does not stick to dust or get clogged, can ensure long-term stable operation, and can adapt to the complex temperature environment of waste incineration flue gas. Attached Figure Description

[0016] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The embodiments of this application and their descriptions are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0017] Figure 1This is a schematic diagram of the structure of the non-metallic tubular gas-to-gas heat exchanger of the present invention;

[0018] Figure 2 This is a schematic diagram of the internal structure of the GGH body of the present invention;

[0019] Figure 3 This is a cross-sectional view of the heat exchange tube of the present invention;

[0020] Figure 4 This is a schematic diagram of the heat exchange tube structure of the present invention;

[0021] Figure 5 This is a schematic diagram of the upper tube sheet structure of the present invention;

[0022] Figure 6 This is a schematic diagram of the structure of the pipe holes in this invention;

[0023] Figure 7 This is a schematic diagram of the structure of the upper skin of the present invention;

[0024] Figure 8 This is a schematic diagram of the tube bundle positioning net of the present invention;

[0025] Figure 9 This is a schematic diagram of the connection structure of the hexagonal ring of the present invention;

[0026] Figure 10 This is a schematic diagram of the connection structure between the hexagonal ring and the limiting rod of the present invention;

[0027] Figure 11 This is an exploded view of the limiting rod of the present invention;

[0028] Figure 12 This is a schematic diagram of the structure of Embodiment 1 of the present invention.

[0029] In the diagram: 1. High-temperature diameter transition section on the shell side of the GGH; 2. Low-temperature diameter transition section on the shell side of the GGH; 3. Low-temperature diameter transition section on the tube side of the GGH; 4. High-temperature diameter transition section on the tube side of the GGH; 5. Baffle smoke box on the shell side of the GGH; 6. GGH body; 6-1. Parallel tube bundle; 6-1-1. Heat exchange tubes; 6-1-2. Expansion pins; 6-1-3. Sealing tube rings; 6-2. Upper tube sheet; 6-2-1. Tube sheet body Body; 6-2-2, Upper skin; 6-2-3, Lower skin; 6-3, Tube bundle positioning net; 6-3-1, Hexagonal ring; 6-3-2, Double-wing tube; 6-3-3, Limiting rod; 6-3-3-1, Pin; 6-3-3-2, Solid hook; 6-3-3-3, Pin ring; 6-3-3-4, Sleeve; 6-3-3-5, Steel wire; 6-4, Baffle plate; 6-5, Breathing plate. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] Reference Figures 1 to 12 As shown, this embodiment provides a non-metallic tube-type gas-to-gas heat exchanger, including a GGH body 6. The top of the GGH body 6 has a high-temperature side diameter transition section 4, and the bottom of the GGH body 6 has a low-temperature side diameter transition section 3. One side of the GGH body 6 has a GGH shell-side baffle smoke box 5, and the top of the side of the GGH body 6 away from the GGH shell-side baffle smoke box 5 has a GGH shell-side high-temperature side diameter transition section 1. The side of the GGH body 6 away from the GGH shell-side baffle smoke box 5 has a GGH shell-side high-temperature side diameter transition section 1. The bottom side of the box 5 is provided with a low-temperature diameter section 2 on the shell side of the GGH. The GGH body 6 is provided with a parallel tube bundle 6-1. The top of the parallel tube bundle 6-1 is fixedly connected to an upper tube sheet 6-2. Multiple tube bundle positioning nets 6-3 are provided at equal intervals on the parallel tube bundle 6-1. A baffle 6-4 is provided in the middle of the parallel tube bundle 6-1. The baffle 6-4 is fixedly connected to the inner wall of the GGH body 6. A breather plate 6-5 is provided at the bottom of the parallel tube bundle 6-1. The parallel tube bundle 6-1 is made of fluoroplastic material.

[0033] After desulfurization, the flue gas enters the lower half of the GGH body 6 through the high-temperature side variable diameter section 1 on the shell side, where heat exchange occurs. It then passes through the GGH shell-side baffle flue box 5, where it exchanges heat again with the upper half of the GGH body 6, raising its temperature. The flue gas then enters the flue gas reheat unit, where it continues to heat up with additional energy input. The desulfurized high-temperature flue gas enters the tube side of the GGH body 6 through the high-temperature side variable diameter section 4 on the tube side, where it releases heat, and is discharged through the low-temperature side variable diameter section 3 on the tube side. The flue gas is then led to the chimney for emission.

[0034] The parallel tube bundle 6-1 is made of fluoroplastic, which has excellent corrosion resistance and can effectively resist highly corrosive substances in waste incineration flue gas, such as sulfur dioxide and hydrogen chloride, achieving zero corrosion and zero leakage. The heat exchange tube 6-1-1 has a certain degree of flexibility, a smooth surface, strong self-cleaning ability, and does not accumulate ash or clog, ensuring long-term stable operation and adapting to the complex temperature environment of waste incineration flue gas. The GGH body 6 is arranged between the desulfurization equipment and the denitrification equipment, using the high-temperature flue gas after denitrification to heat the low-temperature flue gas after desulfurization, which can effectively save some energy consumption. The parallel tube bundle 6-1 structure can reduce fluid resistance and improve heat exchange efficiency.

[0035] Further optimization of the scheme: the in-line tube bundle 6-1 is composed of multiple single tube bundles, each including a heat exchange tube 6-1-1. The top of the heat exchange tube 6-1-1 is provided with an expansion pin 6-1-2, and the bottom of the heat exchange tube 6-1-1 is provided with a sealing tube ring 6-1-3.

[0036] The vertical tube bundle 6-1 adopts a vertical arrangement, with the heat exchange tubes 6-1-1 arranged vertically, which occupies a small area and is easy to install and maintain. The tube-side flue gas and shell-side flue gas exchange heat in a counter-current manner, resulting in high heat exchange efficiency. The tube side of the main body usually adopts a single pass, which can be divided into 1 to 3 passes as needed, and a baffle smoke box is used for transition.

[0037] The expansion bolt 6-1-2 has an outer diameter smaller than the inner diameter of the heat exchanger tube 6-1-1 and is made of stainless steel. It is used to expand and secure the heat exchanger tube 6-1-1 after it has been inserted into the tube sheet. One end of the expansion bolt 6-1-2 is flanged, and the other end is chamfered to ensure a smooth tube end and prevent scratching of the heat exchanger tube 6-1-1 during the expansion process.

[0038] The inner diameter of the sealing ring 6-1-3 is slightly larger than the outer diameter of the heat exchange tube 6-1-1. It fits snugly against the bottom of the heat exchange tube 6-1-1, tightly sealing the flue gas and preventing leakage. When high-temperature gas flows inside the tube, the expansion bolt 6-1-2 expands to ensure a tight seal between the tube and the tube sheet, while the sealing ring 6-1-3 prevents gas leakage from the shell side to the tube side. The expansion bolt 6-1-2 provides reliable fixing and sealing, avoiding damage to the fluoroplastic tubing from welding; the sealing ring 6-1-3 compensates for thermal expansion, preventing leakage at the joint.

[0039] Further optimization of the design resulted in heat exchange tube 6-1-1 being made of fusible polytetrafluoroethylene (PTFE) fluoroplastic, suitable for use at temperatures below 200℃. The tube diameter is 40mm-60mm, and the wall thickness is 1mm-1.5mm, ensuring sufficient strength and good heat transfer performance while resisting erosion and corrosion from flue gas. High-temperature gas flows at high speed within heat exchange tube 6-1-1, rapidly transferring heat to the low-temperature gas outside the tube through the thin-walled structure. Fusible PTFE is corrosion-resistant and anti-scaling, suitable for dusty or acidic gases; the thin-walled design reduces thermal resistance and improves heat exchange efficiency; and the larger tube diameter reduces fluid pressure drop, adapting to high-flow-rate conditions.

[0040] The heat exchanger tubes 6-1-1 can be arranged in either a staggered or linear configuration. The staggered configuration enhances fluid turbulence and improves the heat transfer coefficient, but it results in higher flue gas resistance, making it unsuitable for retrofit projects with limited fan head margins. The linear configuration offers lower flue gas resistance and is suitable for applications with stringent pressure drop requirements. In this design, considering factors such as flue gas flow rate, velocity, and heat transfer requirements, the linear configuration is chosen.

[0041] The scheme is further optimized. The upper tube sheet 6-2 includes a tube sheet body 6-2-1, an upper skin 6-2-2 is provided on the outside of the tube sheet body 6-2-1, a lower skin 6-2-3 is provided at the bottom of the tube sheet body 6-2-1, the upper skin 6-2-2 is fixedly connected to the lower skin 6-2-3, and the upper skin 6-2-2 is fixedly connected to the heat exchange tube 6-1-1.

[0042] The tube sheet body 6-2-1 is made of carbon steel with a thickness of not less than 20mm, and its surface is lined with a 1.5mm fluoroplastic skin. The skin consists of an upper skin 6-2-2 and a lower skin 6-2-3, which prevents the tube sheet from being corroded by flue gas. The heat exchange tubes 6-1-1 are connected to the tube sheet body 6-2-1 by an expansion joint. This expansion joint ensures a tight contact between the heat exchange tubes 6-1-1 and the tube sheet body 6-2-1, guaranteeing a tight seal. The skin is made of the same material as the heat exchange tubes 6-1-1. To prevent flue gas leakage at the tube openings, the upper skin 6-2-2 is welded to the heat exchange tubes 6-1-1, and the upper skin 6-2-2 is welded to the lower skin 6-2-3, ensuring that both the upper skin and the lower skin are protected by fluoroplastic sheets. Simultaneously, the double-layer skin structure enhances the rigidity of the tube sheet and prevents deformation.

[0043] The design is further optimized by having multiple evenly spaced parallel tube holes on the tube sheet body 6-2-1, with heat exchange tubes 6-1-1 installed inside each hole. Multiple bolt holes are also evenly spaced along the edge of the tube sheet body 6-2-1. This parallel layout reduces interference between the heat exchange tubes 6-1-1 and lowers fluid resistance; the bolt hole design facilitates modular assembly and maintenance.

[0044] The tube sheet body 6-2-1 is typically made of steel plate with a thickness of 20mm or more. Bolt holes are designed around the tube sheet body 6-2-1 for equipment installation and positioning. The tube sheet body 6-2-1 has several through holes for sequential tube arrangement, which are slightly larger than the outer diameter of the heat exchange tubes 6-1-1. A radius of r2 is provided on one side to facilitate the subsequent insertion of the heat exchange tubes 6-1-1.

[0045] The upper skin 6-2-2 is sized to match the tube sheet body 6-2-1 and is attached to the upper surface of the tube sheet body 6-2-1, with a flanged edge at the tube holes. The lower skin 6-2-3 is sized to match the tube sheet body 6-2-1 and is attached to the lower surface of the tube sheet body 6-2-1, with the tube hole size larger than the outer diameter of the flanged edge of the upper skin 6-2-2. After the upper skin 6-2-2 and lower skin 6-2-3 are attached to the tube sheet body 6-2-1, the flanged edge of the upper skin 6-2-2 is welded to the lower skin 6-2-3 using a welding process.

[0046] To further optimize the design, double-finned tubes 6-3-2 are provided on both sides of the tube bundle positioning net 6-3. The tube bundle positioning net 6-3 includes multiple hexagonal rings 6-3-1. Heat exchange tubes 6-1-1 are provided inside the hexagonal rings 6-3-1. Two hexagonal rings 6-3-1 located in the horizontal position are connected by a limiting rod 6-3-3.

[0047] The heat exchange tube 6-1-1 is arranged vertically. Since the heat exchange tube 6-1-1 itself has a certain degree of flexibility, a limiting device is required to constrain its position. The positioning mesh 6-3 is arranged at equal intervals along the tube bundle height to limit the lateral vibration of the heat exchange tube 6-1-1. The hexagonal ring structure evenly distributes the load to prevent tube bundle resonance.

[0048] The design is further optimized by providing asymmetrical positioning holes on both sides of the hexagonal ring 6-3-1. The limiting rod 6-3-3 includes a steel wire 6-3-3-5, and a positioning sleeve 6-3-3-4 is provided on the outer sleeve of the steel wire 6-3-3-5. Solid hooks 6-3-3-2 are threaded to both ends of the steel wire 6-3-3-5. A pin 6-3-3-1 is threaded through the solid hook 6-3-3-2. The tail of the pin 6-3-3-1 has an opening, and the opening is connected to the pin ring 6-3-3-3.

[0049] The hexagonal ring 6-3-1 is mold-cast from PFA material, featuring positioning holes on both sides and an asymmetrical design for easy series connection. The pin 6-3-3-1 is also mold-cast from PFA, offering corrosion resistance and sufficient strength. Its open tail design facilitates installation of the pin ring 6-3-3-3, whose inner diameter is smaller than the outer diameter of the open tail end of the pin 6-3-3-1. This snap-fit ​​installation prevents the pin from falling off. The solid hook 6-3-3-2 is threaded to the steel wire 6-3-3-5. The solid hook 6-3-3-2 is a mold-cast PFA material, while the steel wire 6-3-3-5 is made of 316L stainless steel. The positioning sleeve 6-3-3-4 is cut to the required length and is used to fix the spacing between two adjacent heat exchange tubes 6-1-1. The positioning sleeve 6-3-3-4 is a hollow tube and is fitted onto the steel wire 6-3-3-5. The positioning sleeve 6-3-3-4 is made of PFA. The pin 6-3-3-1 and the solid hook 6-3-3-2 allow for quick assembly and disassembly, facilitating maintenance. The steel wire 6-3-3-5 absorbs thermal expansion through elastic deformation, preventing overload of the positioning mesh 6-3.

[0050] The scheme is further optimized by providing multiple baffle holes at equal intervals on the baffle plate 6-4, and heat exchange tubes 6-1-1 are installed inside the baffle holes, with the baffle holes and heat exchange tubes 6-1-1 being fitted with a clearance.

[0051] Baffles 6-4, made of PFA material, are installed as needed to increase the flow path on the shell side and enhance heat transfer. They are bolted to the heat exchanger shell on all four sides. The baffle holes are clearance-fitted with the heat exchange tubes 6-1-1 to accommodate the expansion and contraction of the tubes during thermal expansion. This clearance fit forces the shell-side gas to laterally scour the tube bundle, creating turbulence. The clearance fit also allows for thermal expansion of the heat exchange tubes 6-1-1, preventing stress concentration.

[0052] The design is further optimized by providing multiple heat exchange tube holes at equal intervals on the breather plate 6-5, with heat exchange tubes 6-1-1 installed inside the heat exchange tube holes. The heat exchange tube holes on the breather plate 6-5 allow the heat exchange tubes 6-1-1 to expand and contract axially, and the bottom is sealed to the shell to compensate for the thermal expansion of the tube bundle and prevent the tube sheet from deforming due to temperature differences.

[0053] The breather plate 6-5, made of PFA material, is located at the bottom of the heat exchanger and is fixed to the heat exchanger shell with bolts on all four sides. In the cold state, there is a slight gap (0.1mm) between the inner diameter of the breather plate 6-5's tube hole and the outer diameter of the heat exchange tube 6-1-1. In the hot state, the expansion of the heat exchange tube 6-1-1 is greater than that of the breather plate 6-5. The tube hole of the breather plate 6-5 is interference-fitted with the heat exchange tube 6-1-1 to meet the flue gas tightness requirements and prevent leakage of low-temperature flue gas to high-temperature flue gas. The hot expansion is borne by the breather plate 6-5, which can generate a drum-like effect, displacing upwards or downwards to meet the thermal expansion requirements.

[0054] The design was further optimized so that the outer diameter of the expansion bolt 6-1-2 is smaller than the inner diameter of the heat exchange tube 6-1-1, while the inner diameter of the sealing ring 6-1-3 is larger than the outer diameter of the heat exchange tube 6-1-1. The interference fit of the expansion bolt 6-1-2 ensures reliable fixing and avoids damage to the tube; the gap design of the sealing ring 6-1-3 accommodates thermal expansion and prevents seal failure.

[0055] The GGH shell side baffle smoke box 5 is equipped with baffles 6-4 to guide the flow direction of low-temperature flue gas. It is made of carbon steel and the inner wall is lined with 1.5mm PFA board for anti-corrosion.

[0056] Example 1

[0057] After desulfurization, the 50°C flue gas enters the lower half of the GGH body 6 through the high-temperature side variable diameter section 1 on the shell side, where heat exchange occurs. It then passes through the GGH shell-side baffle flue box 5 and undergoes another heat exchange with the upper half of the GGH body 6, raising the flue gas temperature to 120°C. The flue gas then enters the flue gas reheat unit, where it continues to heat up with additional energy input. After desulfurization, the 180°C high-temperature flue gas enters the tube side of the GGH body 6 through the high-temperature side variable diameter section 4 on the tube side, where it releases heat. It then cools to 118°C and exits through the low-temperature side variable diameter section 3 on the tube side, before being led to the chimney for emission.

[0058] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0059] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A non-metallic tubular gas-to-gas heat exchanger, characterized in that: The system includes a GGH body (6), with a high-temperature side reducing section (4) for the GGH tube side at the top and a low-temperature side reducing section (3) for the GGH tube side at the bottom. A GGH shell-side baffle smoke box (5) is located on one side of the GGH body (6). A high-temperature side reducing section (1) for the GGH shell side is located on the top of the side of the GGH body (6) away from the GGH shell-side baffle smoke box (5). A low-temperature side reducing section (1) for the GGH shell side is located on the bottom of the side of the GGH body (6) away from the GGH shell-side baffle smoke box (5). The temperature-controlled variable diameter section (2) is provided with a parallel tube bundle (6-1) inside the GGH body (6). The top of the parallel tube bundle (6-1) is fixedly connected to an upper tube plate (6-2). Multiple tube bundle positioning nets (6-3) are provided at equal intervals on the parallel tube bundle (6-1). A baffle plate (6-4) is provided in the middle of the parallel tube bundle (6-1). The baffle plate (6-4) is fixedly connected to the inner wall of the GGH body (6). A breather plate (6-5) is provided at the bottom of the parallel tube bundle (6-1). The parallel tube bundle (6-1) is made of fluoroplastic material.

2. The non-metallic tubular gas-to-gas heat exchanger according to claim 1, characterized in that: The parallel tube bundle (6-1) is composed of multiple single tube bundles, each including a heat exchange tube (6-1-1). The top of the heat exchange tube (6-1-1) is provided with an expansion pin (6-1-2), and the bottom of the heat exchange tube (6-1-1) is provided with a sealing tube ring (6-1-3).

3. The non-metallic tubular gas-to-gas heat exchanger according to claim 2, characterized in that: The heat exchange tube (6-1-1) is made of fusible polytetrafluoroethylene fluoroplastic, the diameter of the heat exchange tube (6-1-1) is 40mm-60mm, and the wall thickness of the heat exchange tube (6-1-1) is 1mm-1.5mm.

4. The non-metallic tubular gas-to-gas heat exchanger according to claim 2, characterized in that: The upper tube sheet (6-2) includes a tube sheet body (6-2-1), an upper skin (6-2-2) is provided on the outside of the tube sheet body (6-2-1), a lower skin (6-2-3) is provided at the bottom of the tube sheet body (6-2-1), the upper skin (6-2-2) is fixedly connected to the lower skin (6-2-3), and the upper skin (6-2-2) is fixedly connected to the heat exchange tube (6-1-1).

5. The non-metallic tubular gas-to-gas heat exchanger according to claim 4, characterized in that: The tube sheet body (6-2-1) is provided with a plurality of parallel tube holes at equal intervals, and the heat exchange tube (6-1-1) is provided in the parallel tube holes. The edge of the tube sheet body (6-2-1) is provided with a plurality of bolt holes at equal intervals.

6. The non-metallic tubular gas-to-gas heat exchanger according to claim 2, characterized in that: The tube bundle positioning net (6-3) has double-finned tubes (6-3-2) on both sides. The tube bundle positioning net (6-3) includes multiple hexagonal rings (6-3-1). The heat exchange tube (6-1-1) is located inside the hexagonal ring (6-3-1). Two hexagonal rings (6-3-1) located in a horizontal position are connected by a limiting rod (6-3-3).

7. The non-metallic tubular gas-to-gas heat exchanger according to claim 6, characterized in that: The hexagonal ring (6-3-1) has asymmetrical positioning holes on both sides. The limiting rod (6-3-3) includes a steel wire (6-3-3-5). The steel wire (6-3-3-5) is fitted with a positioning sleeve (6-3-3-4). The two ends of the steel wire (6-3-3-5) are respectively threaded with solid hooks (6-3-3-2). A pin (6-3-3-1) is threaded through the solid hook (6-3-3-2). The tail of the pin (6-3-3-1) is open, and the opening is connected to a pin ring (6-3-3-3).

8. The non-metallic tubular gas-to-gas heat exchanger according to claim 2, characterized in that: The baffle plate (6-4) is provided with a plurality of baffle plate holes at equal intervals, and the heat exchange tube (6-1-1) is provided in the baffle plate holes. The baffle plate holes and the heat exchange tube (6-1-1) are fitted with a clearance.

9. The non-metallic tubular gas-to-gas heat exchanger according to claim 2, characterized in that: The breathing plate (6-5) is provided with a plurality of heat exchange tube holes at equal intervals, and the heat exchange tube (6-1-1) is provided in the heat exchange tube holes.

10. The non-metallic tubular gas-to-gas heat exchanger according to claim 2, characterized in that: The outer diameter of the expansion pin (6-1-2) is smaller than the inner diameter of the heat exchange tube (6-1-1), and the inner diameter of the sealing ring (6-1-3) is larger than the outer diameter of the heat exchange tube (6-1-1).

Images