Waste heat recovery system for exhaust steam at outlet of steam turbine

Abstract

The utility model relates to a steam turbine outlet dead steam waste heat recovery system, which relates to the field of steam turbine dead steam recovery, and comprises a box body, a steam admission mechanism, a control terminal and a recovery mechanism for waste heat recovery, the steam admission mechanism comprises an air guide valve, an air inlet pipe and a pressurizing assembly, the air guide valve is arranged on the box body, the air inlet pipe is arranged on the box body, and the pressurizing assembly is arranged on the box body. The pressurizing assembly comprises a pressurizing box, a water inlet pipe and a water inlet valve, the pressurizing box is arranged in the box body, one end of the pressurizing box is communicated with the air inlet pipe, the water inlet pipe is arranged on the pressurizing box, the water inlet valve is arranged on the water inlet pipe, the pressurizing box is communicated with the recycling mechanism, and the control terminal is arranged on the box body. According to the waste heat recovery device, waste heat recovery can be carried out even in the state that the waste steam pressure is not stable.

Description

Technical Field

[0001] The utility model relates to the field of exhaust steam recovery of steam turbines, in particular to a waste heat recovery system for exhaust steam at a steam turbine outlet. Background Art

[0002] With the continuous growth of energy demand and the increasing attention to environmental protection, improving energy efficiency has become a key issue. Steam turbines are widely used in the industrial field, but the exhaust steam generated during their operation carries a large amount of waste heat, which will cause huge energy waste if it is directly discharged.

[0003] At present, a Chinese utility model patent application with publication number CN220101357U and publication date November 28, 2023 proposes a thermal power plant steam turbine exhaust heat recovery device, including: an exhaust steam heat recovery device: an exhaust steam inlet and a drain valve are provided at the bottom end of the exterior of the exhaust steam heat recovery device, the drain valve and the air outlet are connected to each other, a water inlet valve is provided at the bottom of the exterior of the exhaust steam heat recovery device, a one-way exhaust valve and a water outlet valve are provided at the top of the exhaust steam heat recovery device, an observation window and a liquid level observation window are provided on the middle outer surface of the exhaust steam heat recovery device, and a first ventilation ring and a second ventilation ring are provided inside the exhaust steam heat recovery device.

[0004] When in use, the contact area between the exhaust steam generated by the steam turbine and the heat transfer medium is increased through the first ventilation ring and the second ventilation ring, thereby realizing waste heat recovery of the exhaust steam.

[0005] With respect to the above-mentioned related technologies, during the process of recovering the exhaust steam, when the exhaust steam discharged from the medium and low pressure cylinders is recovered, the pressure and temperature of the exhaust steam will drop, resulting in a low pressure of the exhausted steam or a negative pressure state. After using the above-mentioned waste heat recovery device, the exhaust steam cannot be fully introduced and the heat cannot be recovered, thereby affecting the recovery effect. Utility Model Content

[0006] In order to improve the waste heat recovery effect of exhaust steam, the utility model provides a waste heat recovery system for exhaust steam at a steam turbine outlet.

[0007] The utility model provides a waste heat recovery system for exhaust steam at a steam turbine outlet, which adopts the following technical solutions:

[0008] A waste heat recovery system for exhaust steam at an outlet of a steam turbine comprises a casing, a steam inlet mechanism, a control terminal and a recovery mechanism for recovering waste heat, wherein the steam inlet mechanism comprises an air induction valve, an air inlet pipe and a supercharging assembly, wherein the air induction valve is arranged on the casing, the air inlet pipe is arranged on the casing, one end of the air inlet pipe is communicated with the air induction valve, the supercharging assembly comprises a supercharging box, a water inlet pipe and a water inlet valve, the supercharging box is arranged on the casing, one end of the supercharging box is communicated with the air inlet pipe, the water inlet pipe is arranged on the supercharging box, the water inlet valve is arranged on the water inlet pipe, the supercharging box is communicated with the recovery mechanism, the control terminal is arranged on the casing, and the steam inlet mechanism, the water inlet valve and the recovery mechanism are connected to the control terminal by electrical signals.

[0009] By adopting the above technical scheme, when it is necessary to recover the waste heat of the exhaust steam of the steam turbine, the exhaust steam enters the boosting assembly through the air induction valve and the air inlet pipe. The air induction valve can reduce the possibility of the exhaust steam flowing back to the steam turbine. When the exhaust steam enters the boosting assembly, the exhaust steam is accumulated in the boosting box, and the water inlet valve is opened to spray water into the boosting box. The water droplets evaporate to form water vapor after encountering the high-temperature exhaust steam, thereby increasing the air pressure in the boosting box. With the continuous introduction of exhaust steam, the boosting box is continuously pressurized, and the pressurized water vapor enters the recovery mechanism, and the recovery mechanism is used to absorb the heat in the water vapor, thereby realizing the waste heat recovery of the exhaust steam. The water vapor recovered by the recovery mechanism condenses into water, which can continue to participate in the operation of the steam turbine, thereby realizing the waste heat recovery even under the state of exhaust steam negative pressure, thereby improving the waste heat recovery effect of the exhaust steam.

[0010] Optionally, the boost component further includes a pressure sensor and a temperature sensor, both of which are disposed in the boost box, and the pressure sensor and the temperature sensor are electrically connected to the control terminal.

[0011] By adopting the above technical scheme, during the process of the water inlet valve spraying water, the pressure sensor detects the pressure in the booster tank. When the pressure in the booster tank changes too much, the control terminal can adjust the water spraying amount of the water inlet valve. At the same time, the temperature sensor detects the temperature in the booster tank in real time. If the intake amount of exhaust steam is small, the temperature of the booster tank will decrease. When the pressure change in the booster tank is not obvious, the water intake amount of the water inlet valve can be adjusted according to the temperature conditions, so that the temperature of the water vapor generated by the exhaust steam is more stable, thereby reducing the possibility of more heat loss in the process of recovering waste heat.

[0012] Optionally, the boost component further includes a boost pump, which is disposed on the air intake pipe and is electrically signal connected to the control terminal.

[0013] By adopting the above technical solution, when exhaust steam is introduced through the steam inlet mechanism, since the amount of exhaust steam introduced is unstable, a boost pipe is provided on the intake pipe so that the exhaust steam passing through the intake pipe is boosted and then stably enters the boost box from the intake pipe, thereby making the pressure of the exhaust steam entering the boost box more stable and reducing the possibility of exhaust steam backflow in the boost box.

[0014] Optionally, the boosting assembly further includes an atomization pipeline, and the atomization pipeline is arranged on the water inlet pipe.

[0015] By adopting the above technical solution, when spraying water on the exhaust steam in the booster box, the water in the water inlet pipe is atomized and sprayed through the atomization pipeline, so that the sprayed water is finer, so that the water can better contact with the exhaust steam, thereby improving the boosting conversion effect of the exhaust steam.

[0016] Optionally, the recovery mechanism includes a recovery pipeline, a recovery box and a circulation pipeline, the recovery box is arranged in a box body, the recovery pipeline is arranged in the recovery box, and the circulation pipeline is connected to the recovery box.

[0017] By adopting the above technical scheme, the water vapor generated after the pressurization enters the recovery pipeline. The recovery box connected to the circulation pipeline is provided with circulating water for absorbing heat. The pressurized water vapor passes through the recovery pipeline from top to bottom. The temperature of the recovery liquid at the upper end of the circulation pipeline is higher than the temperature of the recovery liquid at the lower end of the circulation pipeline, which can facilitate the recovery of waste heat. Since the temperature of the recovery pipeline at the lower end is lowered, the water vapor is cooled into water in the recovery pipeline, and then collected and reused in the steam turbine.

[0018] Optionally, the recovery mechanism further includes a flow deflector plate and a guide block, the flow deflector plate is arranged in the recovery pipeline, a guide groove is opened on the flow deflector plate, a plurality of guide blocks are arranged, and the guide blocks are arranged on the flow deflector plate.

[0019] By adopting the above technical scheme, in the process of recovering the waste heat of the water vapor after the exhaust steam is pressurized, the water vapor enters the recovery pipeline, part of the water vapor contacts the guide block, and part of the water vapor enters the guide groove. Under the mutual influence of the guide block and the guide groove, the water vapor on both sides of the guide plate intersect with each other to form a cyclone. The formed cyclone can hinder the subsequent advancement of the water vapor, thereby allowing the water vapor to stay in the recovery pipeline for a longer time, and at the same time, the water vapor can maintain a certain air pressure, so that the heat in the water vapor is absorbed and condensed into water. At the same time, the guide block increases the contact area, improves the heat conduction effect, and further improves the waste heat recovery effect.

[0020] Optionally, the recovery mechanism further includes a heat-conducting component, the heat-conducting component includes a heat-conducting plate, and the heat-conducting plate is spirally arranged on the recovery pipeline.

[0021] By adopting the above technical solution, in the process of recovering the waste heat of the water vapor after the exhaust steam is pressurized, the heat transfer plate transfers the heat in the recovery pipeline, and the heat transfer plate can fully contact the recovery liquid in the recovery box, further improving the recovery effect.

[0022] Optionally, the heat-conducting component further includes a plurality of unidirectional films, and the unidirectional films are all arranged on the heat-conducting plate.

[0023] By adopting the above technical solution, during the waste heat recovery process, the unidirectional membrane in the recovery box sends the recovered liquid with rising temperature to the top of the recovery box, and finally enters the recovery pipeline for cooling, and then enters the recovery box again, circulating in sequence. The unidirectional membrane can reduce the possibility of backflow of the recovered liquid, making the recovery process more stable.

[0024] Optionally, the recycling mechanism further includes a collection box, which is disposed on the box body and is connected to the recycling pipeline.

[0025] By adopting the above technical solution, during the waste heat recovery process, the water generated in the recovery pipeline enters the collection box through the recovery pipeline and is collected centrally. After the collection is completed, the water will be reused in the steam turbine, reducing water waste.

[0026] In summary, the present invention includes at least one of the following beneficial technical effects:

[0027] By setting up a steam inlet mechanism, the waste heat recovery of the exhaust steam can be achieved. The water vapor recovered by the recovery mechanism condenses into water and can continue to participate in the operation of the steam turbine. Even under the state of negative pressure of the exhaust steam, the waste heat recovery can be carried out, thereby improving the waste heat recovery effect of the exhaust steam.

[0028] By setting up a booster component, the temperature of the water vapor generated by the exhaust steam can be made more stable, reducing the possibility of large heat losses in the process of recovering waste heat.

[0029] By setting up a recovery mechanism, the water vapor maintains a certain air pressure so that the heat in the water vapor is absorbed and condensed into water. At the same time, the guide block increases the contact area, improves the heat conduction effect, and further improves the waste heat recovery effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the overall structure of an embodiment of the utility model;

[0031] Figure 2 yes Figure 1 Schematic cross-sectional view of AA in the figure;

[0032] Figure 3 yes Figure 2 A partial enlarged schematic diagram of part B.

[0033] Explanation of the reference numerals: 100, housing; 200, steam inlet mechanism; 210, air induction valve; 220, air inlet pipe; 230, boost assembly; 231, boost box; 232, water inlet pipe; 233, water inlet valve; 234, pressure sensor; 235, temperature sensor; 236, boost pump; 237, atomization pipeline; 300, recovery mechanism; 310, recovery pipeline; 320, recovery box; 330, circulation pipeline; 340, flow control plate; 350, guide block; 360, collection box; 370, heat conduction assembly; 371, heat conduction plate; 372, one-way membrane; 380, guide groove; 400, control terminal. DETAILED DESCRIPTION

[0034] The following combination Figures 1 to 3 The utility model is described in further detail.

[0035] The utility model embodiment discloses a waste heat recovery system for exhaust steam at a steam turbine outlet. Figures 1 to 3 A waste heat recovery system for exhaust steam at a steam turbine outlet mainly includes a box body 100, a steam inlet mechanism 200, a control terminal 400 and a recovery mechanism 300. The steam inlet mechanism 200, the control terminal 400 and the recovery mechanism 300 are all installed on a recovery box 320. Under the control of the control terminal 400, the steam inlet mechanism 200 can stably transport the exhaust steam and convert the exhaust steam into water vapor. Then the recovery mechanism 300 absorbs the heat in the water vapor into the box, thereby completing the recovery of the waste heat of the exhaust steam generated in the steam turbine and improving the waste heat recovery effect of the exhaust steam.

[0036] Reference Figure 1 The steam intake mechanism 200 includes an air induction valve 210, an air intake pipe 220 and a supercharging assembly 230. The air induction valve 210 is fixedly mounted on the housing 100 by bolts. The air intake pipe 220 is fixedly mounted on the housing 100 by bolts. One end of the air intake pipe 220 is connected to the air induction valve 210 through a pipe connection port.

[0037] Reference Figure 1 and Figure 2The boosting assembly 230 includes a boosting box 231, a water inlet pipe 232, a water inlet valve 233, a pressure sensor 234, a temperature sensor 235, a boosting pump 236 and an atomizing pipeline 237. The boosting box 231 is fixed to the box body 100 by bolts, one end of the boosting box 231 is connected to the air inlet pipe 220, the water inlet pipe 232 is fixed to the boosting box 231 by bolts, the water inlet pipe 232 is connected to the boosting box 231, and the water inlet valve 233 is arranged on the water inlet pipe. 232, the boost box 231 is connected to the recovery mechanism 300, the pressure sensor 234 and the temperature sensor 235 are fixed in the boost box 231 by bolts, the pressure sensor 234, the temperature sensor 235 are connected to the control terminal 400 by wire electrical signals, the boost pump 236 is fixed to the intake pipe 220 by bolts, the boost pump 236 is connected to the control terminal 400 by electrical signals, and the atomization pipeline 237 is arranged on the water inlet pipe 232.

[0038] When it is necessary to recover the waste heat of the exhaust steam of the steam turbine, the exhaust steam enters the boosting assembly 230 through the air induction valve 210 and the air intake pipe 220. The air induction valve 210 can reduce the possibility of exhaust steam flowing back to the steam turbine. When the amount of exhaust steam introduced is unstable, a boosting pipe is provided on the air intake pipe 220, so that the exhaust steam passing through the air intake pipe 220 is boosted and then stably enters the boosting box 231 from the air intake pipe 220, so that the pressure of the exhaust steam entering the boosting box 231 is more stable, and at the same time, the possibility of exhaust steam backflow in the boosting box 231 can be reduced.

[0039] When the exhaust steam enters the boosting assembly 230 and accumulates in the boosting box 231, the water inlet valve 233 is opened, and the water in the water inlet pipe 232 is atomized and sprayed through the atomizing pipe 237, so that the sprayed water is finer, so that the water can better contact with the exhaust steam. The water droplets evaporate to form water vapor after encountering the high-temperature exhaust steam, which increases the air pressure in the boosting box 231. With the continuous introduction of exhaust steam, the boosting box 231 is continuously pressurized, and the pressurized water vapor enters the recovery mechanism 300, so that waste heat recovery can be carried out even under the state of exhaust steam negative pressure, thereby improving the waste heat recovery effect of the exhaust steam.

[0040] Reference Figure 2 and Figure 3The recovery mechanism 300 includes a recovery pipeline 310, a recovery box 320, a circulation pipeline 330, a flow deflector plate 340, a guide block 350, a collection box 360 and a heat conduction component 370. The recovery box 320 is fixed in the box body 100 by bolts. The recovery pipeline 310 is arranged in the recovery box 320. One end of the recovery pipeline 310 is connected to the booster box 231. The circulation pipeline 330 is connected to the recovery box 320. The flow deflector plate 340 is arranged in the recovery pipeline 310. The flow deflector plate 340 is provided with a guide groove 380. A plurality of guide blocks 350 are provided. The guide blocks 350 are arranged on the flow deflector plate 340. The collection box 360 is arranged on the box body 100. The collection box 360 is connected to the recovery pipeline 310.

[0041] The water vapor generated after the pressurization enters the recovery pipeline 310. The recovery box 320 connected to the circulation pipeline 330 is provided with circulating water for absorbing heat. The pressurized water vapor passes through the recovery pipeline 310 from top to bottom. Part of the water vapor contacts the guide block 350, and part of the water vapor enters the guide groove 380. Under the mutual influence of the guide block 350 and the guide groove 380, the water vapor on both sides of the guide plate intersects with each other to form a cyclone. The formed cyclone can hinder the subsequent advancement of water vapor, thereby allowing the water vapor to stay in the recovery pipeline 310 for a longer time; the temperature of the recovery liquid at the upper end of the circulation pipeline 330 is higher than the temperature of the recovery liquid at the lower end of the circulation pipeline 330, which can facilitate the recovery of waste heat. Due to the lower temperature of the recovery pipeline 310 at the lower end, the water vapor is cooled into water in the recovery pipeline 310, and then collected and reused in the steam turbine.

[0042] During the waste heat recovery process, the water generated in the recovery pipeline 310 enters the collection box 360 through the recovery pipeline 310, and the water is collected centrally. After the collection is completed, the water will be reused in the steam turbine, reducing water waste.

[0043] Reference Figure 2 The heat conducting component 370 includes a heat conducting plate 371 and a plurality of one-way membranes 372 . The heat conducting plate 371 is spirally arranged on the recovery pipeline 310 , and the one-way membranes 372 are all arranged on the heat conducting plate 371 .

[0044] During the waste heat recovery process, the one-way membrane 372 in the recovery box 320 sends the recovered liquid with the temperature rising to the top of the recovery box 320, and finally enters the recovery pipeline 310 for cooling, and then enters the recovery box 320 again, circulating in sequence. The one-way membrane 372 can reduce the possibility of backflow of the recovered liquid, making the recovery process more stable.

[0045] The implementation principle of a waste heat recovery system for exhaust steam at a steam turbine outlet in the embodiment of the utility model is as follows:

[0046] When it is necessary to recover the waste heat of the exhaust steam of the steam turbine, the exhaust steam enters the boosting assembly 230 through the air inlet valve 210 and the air inlet pipe 220. After the exhaust steam is accumulated in the boosting box 231, water is sprayed into the boosting box 231. The water droplets evaporate to form water vapor after encountering the high-temperature exhaust steam, thereby increasing the air pressure in the boosting box 231 and continuously pressurizing the boosting box 231. The pressurized water vapor enters the recovery mechanism 300, and the recovery mechanism 300 is used to absorb the heat in the water vapor, thereby realizing the waste heat recovery of the exhaust steam. The water vapor recovered by the recovery mechanism 300 condenses into water, which can continue to participate in the operation of the steam turbine, thereby realizing waste heat recovery even under the state of exhaust steam negative pressure, thereby improving the waste heat recovery effect of the exhaust steam.

[0047] The above are all preferred embodiments of the present utility model, and are not intended to limit the protection scope of the present utility model. Therefore, any equivalent changes made based on the structure, shape, and principle of the present utility model should be included in the protection scope of the present utility model.

Claims

1. A waste heat recovery system for exhaust steam at a steam turbine outlet, characterized in that: The invention comprises a housing (100), a steam inlet mechanism (200), a control terminal (400) and a recovery mechanism (300) for recovering waste heat, wherein the steam inlet mechanism (200) comprises an air induction valve (210), an air inlet pipe (220) and a supercharging assembly (230), wherein the air induction valve (210) is arranged on the housing (100), the air inlet pipe (220) is arranged on the housing (100), one end of the air inlet pipe (220) is connected to the air induction valve (210), and the supercharging assembly (230) comprises a supercharging box (231), a water inlet pipe (232) and an air inlet pipe (233). The boosting box (231) is arranged on the box body (100), one end of the boosting box (231) is connected to the air inlet pipe (220), the water inlet pipe (232) is arranged on the boosting box (231), the water inlet valve (233) is arranged on the water inlet pipe (232), the boosting box (231) is connected to the recovery mechanism (300), the control terminal (400) is arranged on the box body (100), and the steam inlet mechanism (200), the water inlet valve (233) and the recovery mechanism (300) are connected to the control terminal (400) via electrical signals.

2. A waste heat recovery system for exhaust steam at a steam turbine outlet according to claim 1, characterized in that: The boosting assembly (230) further comprises a pressure sensor (234) and a temperature sensor (235), wherein the pressure sensor (234) and the temperature sensor (235) are both arranged in the boosting box (231), and the pressure sensor (234) and the temperature sensor (235) are electrically connected to the control terminal (400).

3. The waste heat recovery system for exhaust steam at a steam turbine outlet according to claim 1, characterized in that: The boosting assembly (230) further comprises a boosting pump (236), wherein the boosting pump (236) is arranged on the air intake pipe (220), and the boosting pump (236) is connected to the control terminal (400) via an electrical signal.

4. A waste heat recovery system for exhaust steam at a steam turbine outlet according to claim 1, characterized in that: The boosting assembly (230) further comprises an atomization pipeline (237), wherein the atomization pipeline (237) is arranged on the water inlet pipe (232).

5. A waste heat recovery system for exhaust steam at a steam turbine outlet according to any one of claims 1 to 4, characterized in that: The recovery mechanism (300) comprises a recovery pipeline (310), a recovery box (320) and a circulation pipeline (330); the recovery box (320) is arranged in a box body (100); the recovery pipeline (310) is arranged in the recovery box (320); and the circulation pipeline (330) is in communication with the recovery box (320).

6. A waste heat recovery system for exhaust steam at a steam turbine outlet according to claim 5, characterized in that: The recovery mechanism (300) further comprises a flow deflector plate (340) and a flow guide block (350); the flow deflector plate (340) is arranged in the recovery pipeline (310); a flow guide groove (380) is provided on the flow deflector plate (340); a plurality of flow guide blocks (350) are provided; and the flow guide blocks (350) are arranged on the flow deflector plate (340).

7. A waste heat recovery system for exhaust steam at a steam turbine outlet according to claim 5, characterized in that: The recovery mechanism (300) further comprises a heat conduction component (370), wherein the heat conduction component (370) comprises a heat conduction plate (371), and the heat conduction plate (371) is spirally arranged on the recovery pipeline (310).

8. A waste heat recovery system for exhaust steam at a steam turbine outlet according to claim 7, characterized in that: The heat conduction component (370) further comprises a plurality of one-way films (372), wherein the one-way films (372) are all arranged on the heat conduction plate (371).

9. The waste heat recovery system for exhaust steam at a steam turbine outlet according to claim 5, characterized in that: The recovery mechanism (300) further comprises a collection box (360), wherein the collection box (360) is arranged on the box body (100), and the collection box (360) is in communication with the recovery pipeline (310).

Images