Steam waste heat recovery device

Abstract

This invention relates to the field of steam waste heat recovery technology, specifically a steam waste heat recovery device, comprising Zone A and Zone B separated by a fixed partition and corresponding heat exchange tube assemblies. A sliding steam distribution sleeve is slidably fitted outside the fixed steam distribution cylinder. Condensate in Zone A flows through an overflow weir into a water collection ring groove fixed to the sliding steam distribution sleeve. The increased weight of the accumulated water drives the sliding steam distribution sleeve downward, increasing the steam intake in Zone B and decreasing the steam intake in Zone A. Simultaneously, upstream steam enters the upper pressure chamber, assisting the sliding steam distribution sleeve in continuing to move downward. After the steam pressure and condensate column pressure in Zone A decrease, a piston is triggered, and a siphon is established in the siphon drain pipe. After the water collection ring groove drains and loses weight, a return spring drives the sliding steam distribution sleeve to reset. This invention can automatically adjust the steam distribution between Zone A and Zone B according to the water accumulation status in Zone A and automatically reset after the water accumulation improves, thus improving the continuity and stability of waste heat recovery.

Description

Technical Field

[0001] This invention relates to the field of steam waste heat recovery technology, specifically to a steam waste heat recovery device. Background Technology

[0002] In combined heat and power (CHP), district heating, and industrial production processes, low-pressure steam, exhaust steam, or flash steam, which have waste heat recovery value, are typically generated. These steams still contain a significant amount of latent heat. By transferring the heat carried by the steam to the return water of the heating network or other media to be heated through heat exchange devices, primary heat source consumption can be reduced, and energy utilization efficiency can be improved.

[0003] Existing steam waste heat recovery devices typically employ indirect heat exchange structures, such as shell-and-tube heat exchangers. During operation, the medium to be heated flows within the tube side of the heat exchanger, while steam enters the shell side and contacts the outer wall of the tubes. After releasing heat, steam condenses to form condensate, which collects at the bottom of the heat exchanger and is discharged through drain pipes and condensate traps. The heat exchange status of this type of device is not only related to the steam pressure and flow rate but also affected by the condensate discharge status.

[0004] In actual operation, the pressure and flow rate of upstream steam may fluctuate with equipment start-up and shutdown, changes in production load, or changes in flash evaporation conditions, and the amount of condensate generated will also change accordingly. Meanwhile, factors such as back pressure in the drainage pipeline, the discharge capacity of the condensate trap, and the pressure difference between the inside and outside of the heat exchanger can all affect the actual condensate discharge rate. When the amount of condensate generated exceeds the amount discharged over a period of time, condensate will gradually accumulate in the shell side of the heat exchanger, potentially submerging part of the heat exchange surface, thereby reducing the heat exchange area that steam can effectively contact, affecting heat exchange efficiency and the stability of the outlet water temperature.

[0005] To address the problem of condensate accumulation, existing technologies typically employ methods such as increasing drainage channels, installing steam traps and collection containers, adding pressure balancing pipelines, or using level detection devices to control drainage valves and pumps to improve condensate discharge. These measures primarily aim to increase condensate discharge capacity; however, under conditions such as short-term increases in steam load, increased downstream back pressure, or a temporary decrease in drainage capacity, condensate may still accumulate in localized heat exchange areas.

[0006] For units that rely solely on the existing drainage path to restore heat exchange, once localized condensate has formed, steam typically continues to enter the corresponding heat exchange area along the original path. The effective heat exchange area affected by the condensate decreases, while other unaffected heat exchange areas struggle to share the corresponding steam heat exchange load in a timely manner. Therefore, the unit's heat exchange capacity may remain affected until the condensate is drained and the liquid level returns to normal.

[0007] Therefore, there is still room for improvement in existing steam waste heat recovery devices, specifically in how to adjust the distribution of steam between different heat exchange zones according to the water accumulation status when condensate accumulates for a short period of time, and how to restore the steam distribution status after the water accumulation is eliminated, so as to maintain the continuity and stability of the waste heat recovery process. Summary of the Invention

[0008] The purpose of this invention is to provide a steam waste heat recovery device to solve the problems mentioned in the background art.

[0009] This invention is achieved through the following technical solution: A steam waste heat recovery device includes a shell, a fixed partition, a heat exchange tube assembly in zone A, a heat exchange tube assembly in zone B, a fixed steam distribution cylinder, and a sliding steam distribution sleeve. The fixed partition is disposed inside the shell and divides its internal space into area A and area B. Area A and area B are respectively provided with heat exchange tube groups in area A and area B. The fixed steam distribution cylinder passes vertically through the fixed partition, and its lower end is connected to the steam inlet. The sliding steam distribution sleeve is axially slidably sleeved outside the fixed steam distribution cylinder. The fixed steam distribution cylinder is provided with a fixed steam distribution port for area A and a fixed steam distribution port for area B, respectively leading to area A and area B. The sliding steam distribution sleeve is provided with a steam distribution window for area A and a steam distribution window for area B, corresponding to the two. A water collection area is formed at the bottom of area A. The water collection area of ​​area A is connected to the drainage pipe of area A and is provided with an overflow weir. A water collection ring groove located below the overflow weir is fixedly provided on the sliding steam distribution sleeve. The outer periphery of the sliding steam distribution sleeve is provided with an annular piston portion, and the fixed partition plate is provided with an annular cylinder body through a fixed support seat. The annular piston portion is sealed and slidably disposed in the annular cylinder body and divides it into an upper pressure chamber and a lower pressure chamber. The lower pressure chamber is connected to the A area. A return spring is provided between the annular piston portion and the lower end wall of the annular cylinder body. The sliding steam distribution sleeve is provided with an A-zone pressure tapping groove and a pressure switching groove on its sleeve wall. The A-zone pressure tapping groove extends axially and communicates with the upper pressure chamber. The pressure switching groove penetrates the sleeve wall of the sliding steam distribution sleeve and communicates with the upper pressure chamber. The fixed steam distribution cylinder is provided with an upstream pressure tapping groove that penetrates its cylinder wall and communicates with its interior. When the water accumulates in the water-collecting annular groove, increasing its weight and causing the sliding steam distribution sleeve to move downwards, the effective flow area of ​​the steam distribution window in zone B increases, while the effective flow area of ​​the steam distribution window in zone A decreases. The pressure tapping groove in zone A moves downwards into the annular cylinder and disconnects from zone A. The pressure switching groove is connected to the upstream pressure tapping groove and remains connected during the subsequent downward movement, allowing the steam in the fixed steam distribution cylinder to enter the upper pressure chamber and push the sliding steam distribution sleeve to continue moving downwards.

[0010] Optionally, the water collection ring groove is connected to a siphon drain pipe that moves synchronously with the sliding steam distribution sleeve. The siphon drain pipe extends upward and then bends downward. A one-way drain valve is provided at its drain end. The one-way drain valve opens in the drain direction and restricts external gas from entering the siphon drain pipe in the reverse direction. The lower part of area A is connected to a connecting pipe, the connecting pipe has a horizontal section, a trigger piston is slidably arranged in the horizontal section, and the end of the horizontal section away from area A is connected to a pneumatic transmission pipe, and a limiting ring platform is formed between the connecting pipe and the pneumatic transmission pipe; A trigger spring is installed inside the air pressure transmission pipe. One end of the trigger spring is fixed to the air pressure transmission pipe, and the other end is connected to the trigger piston. The air pressure transmission pipe and the siphon drainage pipe are kept in communication through a movable communication structure that can accommodate the relative axial movement of the two. The steam pressure and condensate column pressure in Zone A cause the trigger piston to press against the limiting ring. After the steam pressure and condensate column pressure in Zone A decrease, the trigger spring pushes the trigger piston away from the limiting ring, thereby reducing the pressure in the siphon drain pipe and establishing siphon drainage. When the water collecting ring groove is filled with water, the sliding steam distribution sleeve is kept in the downward position. After the water collecting ring groove is drained by siphon and its weight is reduced, the return spring drives the sliding steam distribution sleeve to reset.

[0011] Optionally, the movable communication structure includes a sliding communication sleeve disposed at one end of the air pressure transmission pipe, and the siphon drainage pipe is axially slidably inserted into the sliding communication sleeve; the sliding communication sleeve is provided with a communication port communicating with the air pressure transmission pipe, and the siphon drainage pipe is provided with a sliding communication hole extending axially and communicating with its interior; sliding seals are provided on both sides of the sliding communication hole, and the communication port and the sliding communication hole remain connected during the movement of the siphon drainage pipe.

[0012] Optionally, the suction end of the siphon drain pipe extends to the lower part of the water collection ring groove, and its discharge end is lower than the water storage liquid level of the water collection ring groove; the end of the connecting pipe that communicates with the A area is located at the lower part of the water collection area of ​​the A area.

[0013] Optionally, the lower part of the side wall of the annular cylinder is provided with an axially extending groove that penetrates the side wall. The axially extending groove communicates with the area A, and the upper end of the axially extending groove is located below the initial position of the annular piston, so as to connect the upper pressure chamber with the area A after the annular piston moves down to the corresponding position.

[0014] Optionally, the overflow weir is positioned above the connection point between the drainage pipe of area A and the water collection area of ​​area A, and the overflow weir is connected to an overflow pipe, with the outlet end of the overflow pipe located above the opening of the water collection ring groove.

[0015] Optionally, the pressure tapping groove in area A extends along the axial direction of the sliding steam distribution sleeve; when the sliding steam distribution sleeve is in its initial position, the pressure tapping groove in area A is at least partially located outside the annular cylinder and communicates with area A; during the downward movement of the sliding steam distribution sleeve, the pressure tapping groove in area A moves down into the annular cylinder, and the pressure switching groove communicates with the upstream pressure tapping groove and remains connected during the subsequent downward movement.

[0016] Optionally, the shell is provided with a heat network return water inlet and a hot water outlet. The water inlet of the heat exchange tube group in zone A is connected to the heat network return water inlet, the water outlet of the heat exchange tube group in zone A is connected to the water inlet of the heat exchange tube group in zone B, and the water outlet of the heat exchange tube group in zone B is connected to the hot water outlet.

[0017] Optionally, a water collection area is formed at the bottom of area B, and the water collection area is connected to the drainage pipe of area B.

[0018] Optionally, area A and area B are respectively provided with exhaust branch pipes for area A and area B, and exhaust branch pipes for area A and area B are respectively provided with exhaust valves for area A and area B, and are connected to a common exhaust pipe downstream of exhaust valves for area A and area B.

[0019] Compared with the prior art, the present invention has at least the following beneficial effects: 1. By setting an overflow weir in the water collection area of ​​zone A and setting a water collection ring groove below it that is fixedly connected to the sliding steam distribution sleeve, when the condensate in zone A overflows continuously, the weight of the water accumulated in the water collection ring groove can drive the sliding steam distribution sleeve to move downward, thereby increasing the effective flow area of ​​the steam distribution window in zone B and decreasing the effective flow area of ​​the steam distribution window in zone A. This increases the steam supply in zone B and reduces the steam supply in zone A, so that zone B can share the heat exchange capacity reduction caused by water accumulation in zone A, and at the same time reduces the continued generation of condensate in zone A. 2. By having the return water of the heating network flow through the heat exchange tube group in zone A and the heat exchange tube group in zone B in sequence, when the heat exchange capacity in zone A decreases due to the reduction in steam flow, the temperature of the heating network water entering the heat exchange tube group in zone B decreases accordingly. This helps to increase the heat transfer temperature difference between the steam and the heating network water in zone B and improve the heat exchange capacity of zone B. 3. By coordinating the pressure tapping groove in area A, the upstream pressure tapping groove, and the pressure switching groove, the pressure tapping groove in area A is disconnected from area A after the sliding steam distribution sleeve moves down, and the pressure switching groove is connected to the upstream pressure tapping groove. This allows the steam in the fixed steam distribution cylinder to enter the upper pressure chamber and act on the annular piston part. In this way, the upstream steam pressure is used to supplement the driving force provided by the weight of the water accumulated in the water collection ring groove, pushing the sliding steam distribution sleeve to continue to move down, thereby improving the reliability of steam distribution switching. 4. By setting up a siphon drain pipe and connecting it with a trigger piston, trigger spring, and pressure transmission pipe, after the steam intake in zone A decreases and condensate continues to be discharged, the decrease in steam pressure and condensate column pressure in zone A triggers the piston to move, thereby reducing the pressure in the siphon drain pipe and establishing a siphon, thus discharging the condensate in the water collection ring groove; after the water collection ring groove is lightened, the return spring drives the annular piston and sliding steam distribution sleeve to reset, enabling the device to restore the initial steam distribution state after the water accumulation in zone A is improved; 5. By setting an axial connecting groove in the lower part of the side wall of the annular cylinder, when the annular piston moves down to the corresponding position, the upper pressure chamber can be connected with area A, thereby discharging the condensate accumulated in the upper pressure chamber and reducing the obstruction of the residual medium in the upper pressure chamber to the subsequent reset of the sliding steam distribution sleeve. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of the steam waste heat recovery device of the present invention; Figure 2 for Figure 1 Enlarged diagram of section A in the middle; Figure 3 This is a schematic diagram of the cooperation between the air pressure transmission pipe and the siphon drainage pipe in this invention.

[0021] In the diagram: 1. Shell; 2. Fixed partition; 3. Heat exchanger tube assembly in zone A; 4. Heat exchanger tube assembly in zone B; 5. Fixed steam distribution cylinder; 51. Fixed steam distribution port in zone A; 52. Fixed steam distribution port in zone B; 53. Pressure tap in zone A; 54. Upstream pressure tap; 6. Steam inlet; 7. Sliding steam distribution sleeve; 71. Steam distribution window in zone A; 72. Steam distribution window in zone B; 73. Pressure switching groove; 8. Return spring; 9. Annular piston section; 10. Annular cylinder; 101. Upper pressure chamber; 102. Lower pressure chamber; 103. Axial connecting groove; 11. Fixed support seat; 12. Area A water collection area; 121. Overflow weir; 122. Overflow pipe; 13. Area A drainage pipe; 14. Water collection ring groove; 15. Area B water collection area; 16. Area B drainage pipe; 17. Siphon drainage pipe; 171. Sliding connecting hole; 18. One-way drain valve; 19. Connecting pipe; 20. Trigger piston; 21. Trigger spring; 22. Air pressure transmission pipe; 23. Sliding connecting sleeve; 24. Heating network return water inlet; 25. Hot water outlet; 26. Area A vent branch pipe; 261. Area A check vent valve; 27. Area B vent branch pipe; 271. Area B check vent valve. Detailed Implementation

[0022] 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.

[0023] As attached Figure 1-3 As shown, this embodiment provides a steam waste heat recovery device, including a shell 1, a fixed partition 2, a heat exchange tube group in zone A 3, a heat exchange tube group in zone B 4, a fixed steam distribution cylinder 5, and a sliding steam distribution sleeve 7.

[0024] A fixed partition 2 is installed inside the shell 1, dividing the internal space of the shell 1 into zone A and zone B. Zone A is equipped with zone A heat exchange tube assembly 3, and zone B is equipped with zone B heat exchange tube assembly 4. Steam flows through the outside of the heat exchange tube assemblies in zones A and B, exchanging heat with the hot water flowing inside the heat exchange tube assemblies.

[0025] The shell 1 is provided with a heat network return water inlet 24 and a hot water outlet 25. The inlet end of the heat exchange tube group 3 in zone A is connected to the heat network return water inlet 24, the outlet end of the heat exchange tube group 3 in zone A is connected to the inlet end of the heat exchange tube group 4 in zone B, and the outlet end of the heat exchange tube group 4 in zone B is connected to the hot water outlet 25, so that the heat network water flows through the heat exchange tube group 3 in zone A and the heat exchange tube group 4 in zone B in sequence.

[0026] A fixed steam distribution cylinder 5 vertically passes through a fixed partition 2, and its lower end connects to a steam inlet 6. A sliding steam distribution sleeve 7 is axially slidably fitted around the fixed steam distribution cylinder 5. The fixed steam distribution cylinder 5 is provided with a fixed steam distribution port 51 for zone A and a fixed steam distribution port 52 for zone B, respectively. The sliding steam distribution sleeve 7 is correspondingly provided with a steam distribution window 71 for zone A and a steam distribution window 72 for zone B. By axially moving the sliding steam distribution sleeve 7 relative to the fixed steam distribution cylinder 5, the overlapping area between the steam distribution window 71 for zone A and the steam distribution window 72 for zone B and the fixed steam distribution port 51 for zone A and the fixed steam distribution port 52 for zone B, respectively, can be changed, thereby adjusting the amount of steam entering zone A and zone B.

[0027] A water collection area 12 is formed at the bottom of area A, and it is connected to the drainage pipe 13 to drain the condensate formed in area A. The water collection area 12 is also equipped with an overflow weir 121, which is higher than the connection point between the drainage pipe 13 and the water collection area 12, and is connected to an overflow pipe 122. During normal operation, the condensate formed in area A is mainly discharged through the drainage pipe 13. When the amount of condensate generated in area A exceeds the normal drainage capacity, the liquid level rises to the overflow weir 121 and is discharged through the overflow pipe 122.

[0028] A water collecting ring groove 14 is fixedly installed on the sliding steam distribution sleeve 7. The outlet end of the overflow pipe 122 is located above the opening of the water collecting ring groove 14, so that condensate exceeding the overflow weir 121 enters the water collecting ring groove 14. The water collecting ring groove 14 moves axially synchronously with the sliding steam distribution sleeve 7.

[0029] An annular piston portion 9 is provided on the outer periphery of the sliding steam distribution sleeve 7. A fixed support seat 11 is provided on the fixed partition plate 2, and the annular cylinder body 10 is provided on the fixed support seat 11 and surrounds the sliding steam distribution sleeve 7. The annular piston portion 9 is slidably disposed in the annular cylinder body 10 and divides the internal space of the annular cylinder body 10 into an upper pressure chamber 101 and a lower pressure chamber 102, with the lower pressure chamber 102 communicating with area A.

[0030] A return spring 8 is provided between the annular piston part 9 and the lower end wall of the annular cylinder body 10. When the sliding steam distribution sleeve 7 moves downward, the annular piston part 9 compresses the return spring 8; when the effect of keeping the sliding steam distribution sleeve 7 in the downward state decreases, the return spring 8 can push the annular piston part 9 and the sliding steam distribution sleeve 7 to return to their original position.

[0031] The sliding steam distribution sleeve 7 has an A-zone pressure tapping groove 53 and a pressure switching groove 73 on its sleeve wall. The A-zone pressure tapping groove 53 extends axially along the sliding steam distribution sleeve 7, forming a U-shaped or axially extended pressure tapping channel, which communicates with the upper pressure chamber 101. When the sliding steam distribution sleeve 7 is in its initial position, the A-zone pressure tapping groove 53 is at least partially located outside the annular cylinder 10 and communicates with the A-zone, allowing the upper pressure chamber 101 to obtain the pressure from the A-zone. Since the lower pressure chamber 102 is also communicated with the A-zone, there is no significant pressure difference on either side of the annular piston portion 9 for actively driving the sliding steam distribution sleeve 7 to move downward.

[0032] The pressure switching groove 73 penetrates the sleeve wall of the sliding steam distribution sleeve 7 and communicates with the upper pressure chamber 101. An upstream pressure tapping groove 54 is provided on the cylinder wall of the fixed steam distribution cylinder 5, which penetrates the cylinder wall of the fixed steam distribution cylinder 5 and communicates with the interior of the fixed steam distribution cylinder 5.

[0033] The axial positions of the pressure tapping groove 53 in area A, the pressure switching groove 73, and the upstream pressure tapping groove 54 are set according to the working stroke of the sliding steam distribution sleeve 7. When the sliding steam distribution sleeve 7 moves downward, the pressure tapping groove 53 in area A enters the annular cylinder 10 and loses its connection with area A; the pressure switching groove 73 connects with the upstream pressure tapping groove 54 and remains connected during the subsequent downward stroke. Thus, the steam in the fixed steam distribution cylinder 5 can enter the upper pressure chamber 101 through the upstream pressure tapping groove 54 and the pressure switching groove 73.

[0034] Preferably, the positional relationship between the pressure tapping channel 53 in area A, the pressure switching channel 73, and the upstream pressure tapping channel 54 is such that the upstream pressure tapping channel is established after the pressure tapping channel in area A is closed, or the two are basically completed synchronously at the switching critical position, so as to avoid upstream steam continuously and directly entering area A through the upper pressure chamber 101 and the pressure tapping channel 53 in area A.

[0035] During the downward movement of the sliding steam distribution sleeve 7, the effective flow area of ​​the steam distribution window 72 in zone B and the fixed steam distribution port 52 in zone B increases, while the effective flow area of ​​the steam distribution window 71 in zone A and the fixed steam distribution port 51 in zone A decreases, resulting in an increase in the amount of steam entering zone B and a decrease in the amount of steam entering zone A. After the pressure tap 53 in zone A is disconnected from zone A, the steam in the fixed steam distribution cylinder 5 enters the upper pressure chamber 101 through the upstream pressure tap 54 and the pressure switching groove 73, forming a pressure difference with the lower pressure chamber 102, which exerts a downward force on the annular piston part 9 to assist the sliding steam distribution sleeve 7 in continuing to move downward.

[0036] The lower part of the side wall of the annular cylinder 10 is also provided with an axially extending groove 103. The axially extending groove 103 penetrates the side wall of the annular cylinder 10 and communicates with area A, with its upper end located below the initial position of the annular piston 9. Therefore, when the annular piston 9 has not moved down to the position corresponding to the axially extending groove 103, the upper pressure chamber 101 still maintains the corresponding pressure. When the working condition causes the annular piston 9 to move further down to the corresponding position, the upper pressure chamber 101 can communicate with area A through the axially extending groove 103, so that the condensate accumulated in the upper pressure chamber 101 can be discharged into area A, forming a corresponding pressure relief passage.

[0037] The axial connecting groove 103 does not require the annular piston 9 to move to the corresponding position during each switching process. When the downward pressure generated by the upstream steam pressure is insufficient to make the annular piston 9 reach the position, the sliding steam distribution sleeve 7 can remain in the corresponding downward position; when the subsequent water collecting ring groove 14 continues to accumulate water and other factors cause it to move further downward, the axial connecting groove 103 participates in the drainage and connection of the upper pressure chamber 101.

[0038] A water collection area 15 is formed at the bottom of area B. The water collection area 15 is connected to the drainage pipe 16 of area B to discharge the condensate formed by heat exchange in area B.

[0039] To release the water storage function of the water collection ring trough 14 after the restoration of area A, a siphon drain pipe 17 is connected to the water collection ring trough 14. The siphon drain pipe 17 moves synchronously with the sliding steam distribution sleeve 7 and the water collection ring trough 14. Its suction end extends to the lower part of the water collection ring trough 14, and the pipe body extends upward from the water collection ring trough 14 and then bends downward. The discharge end is lower than the water storage liquid level when the water collection ring trough 14 forms a siphon. A one-way drain valve 18 is provided at the discharge end of the siphon drain pipe 17. The one-way drain valve 18 allows condensate to be discharged in the drainage direction and restricts external gas from entering the siphon drain pipe 17 from the discharge end in the opposite direction.

[0040] The lower part of area A is connected to connecting pipe 19. Connecting pipe 19 is bent to form a horizontal section, in which trigger piston 20 is slidably disposed. The end of the horizontal section of connecting pipe 19 away from area A is connected to pneumatic transmission pipe 22. The connection position between connecting pipe 19 and pneumatic transmission pipe 22 forms a stepped limiting ring platform, which is used to limit the movement position of trigger piston 20 towards the pneumatic transmission pipe 22.

[0041] A trigger spring 21 is installed inside the pneumatic transmission tube 22. One end of the trigger spring 21 is fixed to the pneumatic transmission tube 22, and the other end is connected to the trigger piston 20, so that the trigger piston 20 has a tendency to move away from the limiting ring platform.

[0042] One end of the connecting pipe 19, which connects to area A, is located at the lower part of the water collection area 12 in area A. When this connection point is below the condensate level in area A, the pressure acting on the trigger piston 20 towards area A includes the steam pressure in area A and the pressure of the liquid column formed by the condensate above the connection point. When area A is operating normally or the condensate level is high, this pressure overcomes the action of the trigger spring 21, causing the trigger piston 20 to abut against the limiting ring platform.

[0043] A movable connecting structure is provided between the air pressure transmission pipe 22 and the siphon drain pipe 17 to accommodate their relative axial movement. Specifically, a sliding connecting sleeve 23 is provided at one end of the air pressure transmission pipe 22, and the downwardly extending portion of the siphon drain pipe 17 slides axially through the sliding connecting sleeve 23. The sliding connecting sleeve 23 is provided with a connecting port that communicates with the air pressure transmission pipe 22, and the pipe wall of the siphon drain pipe 17 is provided with a sliding connecting hole 171 that extends axially and communicates with its interior.

[0044] The axial length of the sliding connecting hole 171 is adapted to the working stroke of the siphon drain pipe 17, so that when the siphon drain pipe 17 moves up and down with the sliding steam distribution sleeve 7, the sliding connecting hole 171 can always maintain at least partial communication with the connecting port on the sliding connecting sleeve 23. Sliding seals are provided on both sides of the axial direction of the sliding connecting hole 171, so that the siphon drain pipe 17 can move axially relative to the sliding connecting sleeve 23 and maintain airtight communication between the air pressure transmission pipe 22 and the siphon drain pipe 17.

[0045] When condensate overload occurs in zone A, the condensate exceeding the overflow weir 121 enters the water collection ring trough 14 through the overflow pipe 122. As the condensate in the water collection ring trough 14 increases, its weight increases and causes the sliding steam distribution sleeve 7 to initially move downward. After the sliding steam distribution sleeve 7 moves downward, the effective flow area of ​​the steam distribution window 72 in zone B increases, and the effective flow area of ​​the steam distribution window 71 in zone A decreases. At the same time, the pressure tapping groove 53 in zone A enters the annular cylinder 10 and disconnects from zone A. The pressure switching groove 73 establishes a connection with the upstream pressure tapping groove 54, and the upstream steam enters the upper pressure chamber 101 and further pushes the sliding steam distribution sleeve 7 downward.

[0046] After the sliding steam distribution jacket 7 is in the downward position, the steam intake of zone A decreases, and the steam pressure in zone A decreases accordingly. At the same time, the existing condensate in zone A continues to be discharged through the zone A drain pipe 13, causing the condensate level in zone A and the liquid column pressure acting on the trigger piston 20 to decrease. When the pressure acting on the trigger piston 20 towards zone A decreases to an insufficient level to resist the action of the trigger spring 21, the trigger spring 21 pushes the trigger piston 20 away from the limit ring platform.

[0047] After the trigger piston 20 moves, the volume of the gas space on the side away from area A increases. Since this gas space is connected to the inside of the siphon drain pipe 17 via the pressure transmission pipe 22, the sliding connecting sleeve 23, and the sliding connecting hole 171, the gas pressure inside the siphon drain pipe 17 decreases accordingly. During this stage, the one-way drain valve 18 restricts the entry of external air from the drain end, causing the condensate in the water collection ring groove 14 to be drawn into the siphon drain pipe 17 and gradually pass its upper bend.

[0048] When the condensate passes the highest point of the siphon drain pipe 17 and forms a continuous liquid column on the descending side, siphon drainage is established, and the condensate in the water collection ring trough 14 is discharged through the siphon drain pipe 17 and the one-way drain valve 18.

[0049] When the water collecting ring groove 14 is in the water-filled state, its weight is used to keep the sliding steam distribution sleeve 7 in the downward position; as the siphon drainage proceeds, the weight of the water collecting ring groove 14 gradually decreases. When the return spring 8 can overcome the weight of the remaining water in the water collecting ring groove 14 and the sliding resistance, the return spring 8 pushes the annular piston part 9 and the sliding steam distribution sleeve 7 to return to their original position.

[0050] After the sliding steam distribution sleeve 7 is reset, the steam distribution window 71 in zone A and the steam distribution window 72 in zone B return to their initial steam distribution relationship. The pressure tapping slot 53 in zone A returns to its pressure tapping position connected to zone A, and the upper pressure chamber 101 resumes obtaining pressure from zone A. As steam supply to zone A resumes and the pressure obtained by the connecting pipe 19 rises again, the trigger piston 20 overcomes the action of the trigger spring 21 and abuts against the limiting ring platform again, thus returning to the initial state of the next working cycle.

[0051] Area A is equipped with an exhaust branch pipe 26, and Area B is equipped with an exhaust branch pipe 27. Exhaust branch pipes 26 and 27 are respectively equipped with an A-area check valve 261 and a B-area check valve 271. The two exhaust branch pipes are connected to a common exhaust pipe downstream of their respective check valves. The A-area check valve 261 and the B-area check valve 271 can prevent reverse airflow between Area A and Area B while sharing the common exhaust pipe.

Claims

1. A steam waste heat recovery device, characterized in that: It includes a shell (1), a fixed partition (2), a heat exchange tube assembly in zone A (3), a heat exchange tube assembly in zone B (4), a fixed steam distribution cylinder (5), and a sliding steam distribution sleeve (7); The fixed partition (2) is disposed inside the shell (1) and divides its internal space into area A and area B. Area A and area B are respectively provided with heat exchange tube group (3) in area A and heat exchange tube group (4) in area B. The fixed steam distribution cylinder (5) passes vertically through the fixed partition (2), and its lower end is connected to the steam inlet (6). The sliding steam distribution sleeve (7) is axially slidably sleeved outside the fixed steam distribution cylinder (5). The fixed steam distribution cylinder (5) is provided with a fixed steam distribution port (51) for area A and a fixed steam distribution port (52) for area B, which respectively lead to area A and area B. The sliding steam distribution sleeve (7) is provided with a steam distribution window (71) for area A and a steam distribution window (72) for area B, which correspond to the two. A water collection area (12) is formed at the bottom of the A area. The water collection area (12) is connected to the drainage pipe (13) of the A area and is provided with an overflow weir (121). A water collection ring groove (14) located below the overflow weir (121) is fixedly provided on the sliding steam distribution sleeve (7). The outer periphery of the sliding steam distribution sleeve (7) is provided with an annular piston part (9), and the fixed partition plate (2) is provided with an annular cylinder body (10) through a fixed support seat (11). The annular piston part (9) is sealed and slidably disposed in the annular cylinder body (10) and divides it into an upper pressure chamber (101) and a lower pressure chamber (102). The lower pressure chamber (102) is connected to the A area. A return spring (8) is provided between the annular piston part (9) and the lower end wall of the annular cylinder body (10). The sliding steam distribution sleeve (7) is provided with an A-zone pressure tapping groove (53) and a pressure switching groove (73) on its sleeve wall. The A-zone pressure tapping groove (53) extends axially and communicates with the upper pressure chamber (101). The pressure switching groove (73) penetrates the sleeve wall of the sliding steam distribution sleeve (7) and communicates with the upper pressure chamber (101). The fixed steam distribution cylinder (5) is provided with an upstream pressure tapping groove (54) that penetrates its cylinder wall and communicates with its interior. When the water accumulation in the water collection ring groove (14) increases in weight and causes the sliding steam distribution sleeve (7) to move downward, the effective flow area of ​​the steam distribution window (72) in zone B increases, and the effective flow area of ​​the steam distribution window (71) in zone A decreases. The pressure tapping groove (53) in zone A moves downward into the annular cylinder (10) and disconnects from the zone A. The pressure switching groove (73) is connected to the upstream pressure tapping groove (54) and remains connected during the subsequent downward movement, so that the steam in the fixed steam distribution cylinder (5) enters the upper pressure chamber (101) and pushes the sliding steam distribution sleeve (7) to continue to move downward.

2. The steam waste heat recovery device according to claim 1, characterized in that: The water collection ring groove (14) is connected to a siphon drain pipe (17) that moves synchronously with the sliding steam distribution sleeve (7). The siphon drain pipe (17) extends upward and then bends downward. A one-way drain valve (18) is provided at its drain end. The one-way drain valve (18) opens in the drain direction and restricts external gas from entering the siphon drain pipe (17) in the reverse direction. The lower part of the A area is connected to the connecting pipe (19), the connecting pipe (19) has a horizontal section, a trigger piston (20) is slidably arranged in the horizontal section, and the end of the horizontal section away from the A area is connected to the air pressure transmission pipe (22). A limiting ring platform is formed between the connecting pipe (19) and the air pressure transmission pipe (22). A trigger spring (21) is provided inside the air pressure transmission pipe (22). One end of the trigger spring (21) is fixed to the air pressure transmission pipe (22), and the other end is connected to the trigger piston (20). The air pressure transmission pipe (22) and the siphon drain pipe (17) are kept in communication through a movable communication structure that can adapt to the relative axial movement of the two. The steam pressure and condensate column pressure in Zone A cause the trigger piston (20) to abut against the limiting ring platform; after the steam pressure and condensate column pressure in Zone A decrease, the trigger spring (21) pushes the trigger piston (20) away from the limiting ring platform, thereby reducing the pressure in the siphon drain pipe (17) and establishing siphon drainage. When the water collecting ring groove (14) stores water, the sliding steam distribution sleeve (7) is kept in the downward position. After the water collecting ring groove (14) is drained by siphon to reduce its weight, the return spring (8) drives the sliding steam distribution sleeve (7) to reset.

3. The steam waste heat recovery device according to claim 2, characterized in that: The movable connection structure includes a sliding connecting sleeve (23) disposed at one end of the air pressure transmission pipe (22), and the siphon drain pipe (17) is axially slidably inserted into the sliding connecting sleeve (23); the sliding connecting sleeve (23) is provided with a connecting port that communicates with the air pressure transmission pipe (22), and the siphon drain pipe (17) is provided with a sliding connecting hole (171) that extends axially and communicates with its interior; sliding seals are provided on both sides of the sliding connecting hole (171), and the connecting port and the sliding connecting hole (171) remain connected during the movement of the siphon drain pipe (17).

4. The steam waste heat recovery device according to claim 2, characterized in that: The suction end of the siphon drain pipe (17) extends to the lower part of the water collection ring groove (14), and its discharge end is lower than the water storage liquid level of the water collection ring groove (14); the end of the connecting pipe (19) that communicates with the A area is located at the lower part of the A area water collection area (12).

5. The steam waste heat recovery device according to claim 1, characterized in that: The lower part of the side wall of the annular cylinder (10) is provided with an axially extending groove (103) that penetrates the side wall. The axially extending groove (103) communicates with the A area, and the upper end of the axially extending groove (103) is located below the initial position of the annular piston (9) so as to connect the upper pressure chamber (101) and the A area after the annular piston (9) moves down to the corresponding position.

6. The steam waste heat recovery device according to claim 1, characterized in that: The overflow weir (121) is set above the connection position between the drainage pipe (13) of area A and the water collection area (12) of area A. The overflow weir (121) is connected to an overflow pipe (122), and the outlet end of the overflow pipe (122) is located above the opening of the water collection ring groove (14).

7. The steam waste heat recovery device according to claim 1, characterized in that: The pressure tapping groove (53) in area A extends along the axial direction of the sliding steam distribution sleeve (7); when the sliding steam distribution sleeve (7) is in its initial position, the pressure tapping groove (53) in area A is at least partially located outside the annular cylinder (10) and communicates with area A; during the downward stroke of the sliding steam distribution sleeve (7), the pressure tapping groove (53) in area A moves down into the annular cylinder (10), and the pressure switching groove (73) communicates with the upstream pressure tapping groove (54) and remains connected during the subsequent downward stroke.

8. The steam waste heat recovery device according to claim 1, characterized in that: The shell (1) is provided with a heat network return water inlet (24) and a hot water outlet (25). The inlet end of the heat exchange tube group (3) in zone A is connected to the heat network return water inlet (24). The outlet end of the heat exchange tube group (3) in zone A is connected to the inlet end of the heat exchange tube group (4) in zone B. The outlet end of the heat exchange tube group (4) in zone B is connected to the hot water outlet (25).

9. The steam waste heat recovery device according to claim 1, characterized in that: A water collection area (15) is formed at the bottom of the B area, and the water collection area (15) is connected to the drainage pipe (16) of the B area.

10. The steam waste heat recovery device according to claim 1, characterized in that: The A zone and the B zone are respectively provided with an A zone exhaust branch pipe (26) and a B zone exhaust branch pipe (27). The A zone exhaust branch pipe (26) and the B zone exhaust branch pipe (27) are respectively provided with an A zone check exhaust valve (261) and a B zone check exhaust valve (271). Downstream of the A zone check exhaust valve (261) and the B zone check exhaust valve (271), they are connected to a common exhaust pipe.

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