Gland steam extraction system

Abstract

The present application relates to nuclear power technology field, provide a kind of steam seal air extraction system, comprising: steam turbine unit, refrigeration subsystem and absorber, steam turbine unit has steam seal cavity in two ends;Absorber is connected with refrigeration subsystem to form circulation loop, absorber is connected with air extraction pipe and exhaust pipe, air extraction pipe is used to suck air and water vapor in steam seal cavity into absorber, lithium bromide solution is provided in absorber, and lithium bromide solution is used to absorb water vapor.The steam seal air extraction system described above can suck air and water vapor leaked in steam seal cavity of steam turbine unit into absorber, and water vapor is absorbed by absorber, realizes refrigeration and air extraction simultaneously, meets the air extraction demand of steam turbine unit, also takes into account refrigeration demand, eliminates the problem of system complex, numerous equipment, high auxiliary energy consumption and large volume, weight caused by air extractor and refrigeration unit independent operation, realizes the simplification of power conversion device overall composition and operation efficiency improvement.

Description

Technical Field

[0001] This invention relates to the field of nuclear power technology, and in particular to a steam seal extraction system. Background Technology

[0002] The power conversion unit in a nuclear power plant is the central link in converting nuclear thermal energy into electrical energy. In this unit, the turbine rotor extends out of the cylinder at the shaft end, creating a problem of steam leakage at the high-pressure end and air leakage at the low-pressure end. It is necessary to continuously extract the leaking steam and air from the shaft seals. Therefore, the power conversion unit is typically equipped with steam jet ejectors, water jet ejectors, or vacuum pumps to extract the mixture of air and steam.

[0003] Meanwhile, nuclear power plant power conversion units contain a large number of high-temperature devices, and the surrounding ambient temperature is high, requiring continuous cooling from refrigeration units to ensure the safe operation of the equipment. Currently, the extraction equipment and refrigeration units usually operate independently, resulting in problems such as complex system structure, equipment redundancy, high auxiliary energy consumption, and large size and weight. Summary of the Invention

[0004] This invention provides a vapor seal extraction system to solve the defects of existing technologies, such as complex system structure, redundant equipment, high auxiliary energy consumption, and large size and weight, caused by the independent operation of extraction equipment and refrigeration unit.

[0005] This invention provides a steam seal extraction system, comprising: a steam turbine unit with steam seal cavities at both ends, the steam seal cavities being connected to the interior of the steam turbine unit; a refrigeration subsystem for converting saturated steam into water vapor; an absorber connected to the refrigeration subsystem to form a circulation loop, the first inlet of the absorber being connected to an extraction pipe, the extraction pipe being connected to the steam seal cavity, the extraction pipe being used to draw air and water vapor from the steam seal cavity into the absorber, the first outlet of the absorber being connected to an exhaust pipe, the exhaust pipe being used to discharge air, and a lithium bromide solution being provided inside the absorber for absorbing the water vapor.

[0006] According to a steam seal extraction system provided by the present invention, the steam turbine unit includes: a steam turbine, a first end of the steam turbine is provided with multiple stages of first steam seals, a first steam seal cavity is formed between adjacent first steam seals, the first steam seal cavity is in communication with the interior of the steam turbine, a second end of the steam turbine is provided with multiple stages of second steam seals, a second steam seal cavity is formed between adjacent second steam seals, the second steam seal cavity is in communication with the interior of the steam turbine, and both the first steam seal cavity and the second steam seal cavity are connected to the extraction pipe; a balance chamber, the inlet of the balance chamber is in communication with the first steam seal cavity, and the outlet of the balance chamber is in communication with the second steam seal cavity.

[0007] According to a steam seal extraction system provided by the present invention, the first steam seal chamber includes: a primary first steam seal chamber, which is connected to the interior of the steam turbine, and the inlet of the balance chamber is connected to the primary first steam seal chamber; a secondary first steam seal chamber, which is connected to the primary first steam seal chamber, and the secondary first steam seal chamber is connected to the extraction pipe.

[0008] According to a steam seal extraction system provided by the present invention, the second steam seal chamber includes: a primary second steam seal chamber communicating with the interior of the steam turbine, the outlet of the balance chamber communicating with the primary second steam seal chamber; and a secondary second steam seal chamber communicating with the primary second steam seal chamber, the secondary second steam seal chamber being connected to the extraction pipe.

[0009] According to a vapor sealing and extraction system provided by the present invention, the refrigeration subsystem includes: a refrigeration unit for generating water vapor and cooling the surrounding environment, the outlet of the refrigeration unit being connected to the second inlet of the absorber; and a heating unit, the inlet of the heating unit being connected to the second outlet of the absorber, the first outlet of the heating unit being connected to the inlet of the refrigeration unit, the heating unit being used to heat a lithium bromide solution to generate saturated vapor, the saturated vapor entering the refrigeration unit.

[0010] According to a vapor sealing and extraction system provided by the present invention, the refrigeration unit includes: a condenser, the inlet of which is connected to a first outlet of the heating unit, the condenser being used to condense the saturated vapor to produce condensate; a first throttling valve connected to the outlet of the condenser; and an evaporator, the inlet of which is connected to the first throttling valve, and the outlet of which is connected to a second inlet of the absorber; wherein the condensate enters the evaporator after passing through the first throttling valve to form water vapor.

[0011] According to a vapor sealing and extraction system provided by the present invention, the heating unit includes: a first pipeline, the first end of the first pipeline being connected to the second outlet of the absorber; and a steam generator, the inlet of the steam generator being connected to the second end of the first pipeline, and the first outlet of the steam generator being connected to the inlet of the condenser. The steam generator is used to heat a lithium bromide solution to generate saturated steam.

[0012] According to a steam seal extraction system provided by the present invention, the heating unit further includes a first pump, which is disposed in the first pipeline and is used to pump the lithium bromide solution in the absorber to the steam generator.

[0013] According to a steam seal extraction system provided by the present invention, the heating unit further includes: a second pipeline, the two ends of which are respectively connected to the second outlet of the steam generator and the third inlet of the absorber, so that the lithium bromide solution flows back from the steam generator to the absorber; and a second throttle valve disposed in the second pipeline.

[0014] According to the present invention, a vapor seal extraction system further includes a second pump, which is disposed in the exhaust pipe.

[0015] The steam seal extraction system provided by this invention, by setting up a refrigeration subsystem and an absorber, can draw air and water vapor leaking into the steam seal cavity of the steam turbine unit into the absorber, where the absorber absorbs the water vapor and discharges the air. This achieves simultaneous operation of refrigeration and extraction, meeting the extraction requirements of the steam turbine unit while also taking into account the refrigeration requirements. It eliminates the need for auxiliary systems, equipment, pipelines, and supporting facilities such as the original condenser main extraction system, as well as the necessary steam ejector, water ejector, cooling water, and electric vacuum pump. It also eliminates the problems of system complexity, numerous equipment, high auxiliary energy consumption, and large size and weight caused by the independent operation of the ejector and refrigeration unit. This simplifies the overall composition of the power conversion device and improves its operational efficiency. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of the vapor sealing and extraction system provided by the present invention.

[0018] Figure label: 110. Absorber; 111. Extraction pipe; 112. Exhaust pipe; 113. Second cooling pipe; 120. Condenser; 121. First cooling pipe; 130. First throttle valve; 140. Evaporator; 150. Steam generator; 151. First pipeline; 152. First pump; 153. Second pipeline; 154. Second throttle valve; 160. Second pump; 200. Steam turbine; 210. First steam seal; 211. First-stage first steam seal chamber; 212. Second-stage first steam seal chamber; 220. Second steam seal; 221. First-stage second steam seal chamber; 222. Second-stage second steam seal chamber; 230. Balance chamber. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0020] The following is combined Figure 1 The present invention describes a vapor seal extraction system.

[0021] like Figure 1 As shown, in an embodiment of the present invention, the steam seal extraction system includes: a steam turbine unit, a refrigeration subsystem, and an absorber 110. Steam seal cavities are provided at both ends of the steam turbine unit, and the steam seal cavities are connected to the interior of the steam turbine unit. The refrigeration subsystem is used to convert saturated steam into water vapor. The absorber 110 is connected to the refrigeration subsystem to form a circulation loop. The first inlet of the absorber 110 is connected to an extraction pipe 111, which is connected to the steam seal cavity. The extraction pipe 111 is used to draw air and water vapor from the steam seal cavity into the absorber 110. The first outlet of the absorber 110 is connected to an exhaust pipe 112, which is used to discharge air. The absorber 110 contains a lithium bromide solution, which is used to absorb water vapor.

[0022] Specifically, when the turbine unit is performing work, some water vapor in the turbine unit cylinder leaks into the steam seal chambers at both ends of the turbine unit. The water vapor and air in the steam seal chambers are drawn into the absorber 110 through the extraction pipe 111. The water vapor and air do not condense in the absorber 110. The water vapor is absorbed by the lithium bromide solution, and the air is discharged through the exhaust pipe 112 to extract air from the turbine unit.

[0023] The refrigeration subsystem condenses saturated vapor into water, then evaporates the water into water vapor. During evaporation, the water absorbs heat to cool the surrounding environment. The water vapor enters absorber 110 and is absorbed by the lithium bromide solution. The lithium bromide solution is then heated, causing some of the water to evaporate into saturated vapor. This saturated vapor is then condensed back into water, continuing the cycle.

[0024] In this embodiment, the absorber 110 operates under a high vacuum, enabling it to draw vapor and air from low vacuum or positive pressure equipment. The circulation loop consisting of the refrigeration subsystem and the absorber 110 utilizes absorption refrigeration technology to cool low-grade heat sources, maintaining the ambient temperature within an acceptable range.

[0025] In an embodiment of the present invention, the absorber 110 contains a lithium bromide solution. The lithium bromide solution has an extremely strong absorption capacity for water vapor. At normal pressure, the boiling point of the lithium bromide solution is as high as 1265°C. Therefore, when heated, the solution itself will not boil; only the water (refrigerant) within it will evaporate, forming saturated vapor to achieve working fluid separation. Furthermore, the partial pressure of water vapor on the surface of the lithium bromide solution is much lower than that of pure water, thus enabling it to strongly absorb water vapor at lower temperatures.

[0026] The steam seal extraction system provided in this invention, by setting up a refrigeration subsystem and an absorber, can draw air and water vapor leaking into the steam seal cavity of the steam turbine unit into the absorber, where the absorber absorbs the water vapor and discharges the air. This achieves simultaneous operation of refrigeration and extraction, meeting the extraction requirements of the steam turbine unit while also taking into account the refrigeration requirements. It eliminates the need for auxiliary systems, equipment, pipelines, and supporting facilities such as the original condenser main extraction system, as well as the necessary steam ejector, water ejector, cooling water, and electric vacuum pump. It also eliminates the problems of system complexity, numerous equipment, high auxiliary energy consumption, and large size and weight caused by the independent operation of the ejector and refrigeration unit. This simplifies the overall composition of the power conversion device and improves its operational efficiency.

[0027] like Figure 1 As shown, in an embodiment of the present invention, the turbine unit includes a turbine 200 and a balance chamber 230. A multi-stage steam seal is provided between the rotor and the cylinder ends of the turbine 200. Specifically, the first end of the turbine 200, i.e., the high-pressure end, is provided with a multi-stage first steam seal 210, with a first steam seal cavity formed between adjacent first steam seals 210. The second end of the turbine 200, i.e., the low-pressure end, is provided with a multi-stage second steam seal 220, with a second steam seal cavity formed between adjacent second steam seals 220. Both the first and second steam seal cavities are connected to the interior of the turbine 200. When the turbine is working, some high-pressure steam leaks into the first steam seal cavity. The inlet of the balance chamber 230 is connected to the first steam seal cavity, and the outlet of the balance chamber 230 is connected to the second steam seal cavity. A portion of the high-pressure steam leaking into the first steam seal cavity is drawn into the absorber 110 by the extraction pipe 111 and absorbed by the lithium bromide solution; the remaining portion enters the second steam seal cavity through the balance chamber. The low-pressure steam entering the second steam seal chamber partially enters the steam turbine 200, while the remainder is drawn into the absorber 110 by the extraction pipe 111 and absorbed by the lithium bromide solution.

[0028] Furthermore, such as Figure 1As shown, in an embodiment of the present invention, the first steam sealing chamber includes a primary first steam sealing chamber 211 and a secondary first steam sealing chamber 212. The interior of the steam turbine 200, the primary first steam sealing chamber 211, and the secondary first steam sealing chamber 212 are sequentially connected. When the steam turbine 200 is performing work, the high-pressure steam leaking into the primary first steam sealing chamber 211 enters the secondary first steam sealing chamber 212, and some of the high-pressure steam enters the balance chamber 230. The high-pressure steam entering the secondary first steam sealing chamber 212 is drawn into the absorber 110 by the extraction pipe 111 and absorbed.

[0029] Further, in an embodiment of the present invention, the second steam seal cavity includes a primary second steam seal cavity 221 and a secondary second steam seal cavity 222. The interior of the steam turbine 200, the primary second steam seal cavity 221, and the secondary second steam seal cavity 222 are sequentially connected. Water vapor entering the balance chamber 230 enters the primary second steam seal cavity 221, wherein some water vapor returns to the interior of the steam turbine 200, and some water vapor leaks into the secondary second steam seal cavity 222. The secondary second steam seal cavity 222 is connected to the extraction pipe 111, and the water vapor in the secondary second steam seal cavity 222 is drawn into the absorber 110 by the extraction pipe 111 for absorption, thereby ensuring that all water vapor leaking into the steam seal cavities at both ends of the steam turbine 200 can be drawn in.

[0030] It should be noted that the air in the secondary first steam seal chamber 212 and the secondary second steam seal chamber 222 is also drawn into the absorber 110 by the extraction pipe 111 and discharged by the exhaust pipe 112.

[0031] like Figure 1 As shown, in an embodiment of the present invention, the refrigeration subsystem includes a refrigeration unit and a heating unit. The refrigeration unit is used to generate water vapor and cool the surrounding environment, and its outlet is connected to the second inlet of the absorber 110. The inlet of the heating unit is connected to the second outlet of the absorber 110, and its first outlet is connected to the inlet of the refrigeration unit. The heating unit is used to heat the lithium bromide solution to generate saturated vapor.

[0032] Specifically, the refrigeration unit, absorber 110, and heating unit form a refrigeration extraction circulation loop. The refrigeration unit is used to cool the surrounding environment inside the power conversion device. Saturated vapor condenses in the refrigeration unit to form condensate, which absorbs heat to become water vapor, simultaneously cooling the surrounding environment. The water vapor enters the absorber 110 and is absorbed by the lithium bromide solution. The non-condensable air in the absorber 110 is discharged through the exhaust pipe 112. The lithium bromide solution enters the heating unit and is heated, where some water evaporates into saturated vapor. The saturated vapor enters the refrigeration unit and re-forms into water vapor, achieving a cyclical transformation of water vapor and saturated vapor, while simultaneously cooling the surrounding environment.

[0033] In this embodiment, the circulation loop consisting of the refrigeration unit, the absorber 110, and the heating unit is used to cool the surrounding environment. The absorber 110 simultaneously extracts air from the turbine 200, realizing simultaneous operation of refrigeration and extraction. While cooling the surrounding environment inside the power conversion device, the extraction requirements of the turbine 200 are also guaranteed.

[0034] Specifically, such as Figure 1 As shown, in an embodiment of the present invention, the refrigeration unit includes a condenser 120, a first throttling valve 130, and an evaporator 140. The inlet of the condenser 120 is connected to the first outlet of the heating unit, the outlet of the condenser 120 is connected to the inlet of the first throttling valve 130, the outlet of the first throttling valve 130 is connected to the inlet of the evaporator 140, and the outlet of the evaporator 140 is connected to the second inlet of the absorber 110.

[0035] The condenser 120 is equipped with a first cooling pipe 121, through which a first cooling medium flows. Saturated steam exchanges heat with the first cooling medium and condenses into condensate. The condensate is then throttled, depressurized, and cooled by a first throttling valve 130 before entering the evaporator 140. In the evaporator 140, the condensate absorbs heat and evaporates into water vapor, simultaneously providing a cooling effect to the surrounding environment. The water vapor then enters the absorber 110, which is equipped with a second cooling pipe 113, through which a second cooling medium flows. The water vapor dissolves in the lithium bromide solution, and the heat from the water vapor is carried away by the second cooling medium. At this point, the concentration of the lithium bromide solution decreases. The lithium bromide solution with the decreased concentration enters the heating unit and is heated, where some water evaporates into saturated steam. This saturated steam then enters the condenser 120 and condenses again into condensate for the next cycle. At this point, the concentration of the lithium bromide solution in the heating unit increases.

[0036] like Figure 1 As shown, in an embodiment of the present invention, the heating unit includes a steam generator 150 and a first pipe 151. The first end of the first pipe 151 is connected to the second outlet of the absorber 110, and the second end of the first pipe 151 is connected to the inlet of the steam generator 150. The lithium bromide solution in the absorber 110 enters the steam generator 150 through the first pipe 151. The steam generator 150 is equipped with a heating tube, under the action of the heating tube, some of the water in the lithium bromide solution evaporates into saturated steam. The first outlet of the steam generator 150 is connected to the inlet of a condenser 120, so that the generated saturated steam enters the condenser 120 and is converted into condensate.

[0037] Furthermore, in an embodiment of the present invention, the heating unit further includes a first pump 152, which is disposed in the first pipeline 151 and is used to pump the lithium bromide solution in the absorber 110 to the steam generator 150.

[0038] like Figure 1 As shown, in an embodiment of the present invention, the heating unit further includes a second pipe 153 and a second throttle valve 154. The two ends of the second pipe 153 are respectively connected to the second outlet of the steam generator 150 and the third inlet of the absorber 110, so that the lithium bromide solution with increased concentration can flow back from the steam generator 150 to the absorber 110. The second throttle valve 154 is disposed in the second pipe 153 and is used to depressurize the lithium bromide solution with increased concentration, allowing the depressurized lithium bromide solution to flow back to the absorber 110. Water vapor generated again by the refrigeration unit enters the absorber 110, further reducing the concentration of the lithium bromide solution. The reduced-concentration lithium bromide solution then re-enters the steam generator 150 for heating, generating saturated steam.

[0039] That is, in the embodiments of the present invention, the condenser 120, the first throttle valve 130, the evaporator 140, the absorber 110, and the steam generator 150 form a water vapor-saturated steam conversion loop; the absorber 110, the first pump 152, the steam generator 150, and the second throttle valve 154 form a lithium bromide dilute solution-lithium bromide viscous solution conversion loop. The two loops operate simultaneously to achieve simultaneous refrigeration and vacuuming.

[0040] like Figure 1 As shown, in an embodiment of the present invention, the vapor seal extraction system further includes a second pump 160, which is disposed in the exhaust pipe 112. The second pump 160 is used to draw air from the absorber 110 and discharge it outside the absorber 110 through the exhaust pipe 112.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A vapor sealing extraction system, characterized in that, include: A steam turbine unit, wherein the steam turbine unit has steam sealing chambers at both ends, and the steam sealing chambers are connected to the interior of the steam turbine unit; The refrigeration subsystem is used to convert saturated steam into water vapor. An absorber is connected to the refrigeration subsystem to form a circulation loop. The first inlet of the absorber is connected to a suction pipe, which is connected to the vapor seal chamber. The suction pipe is used to draw air and water vapor from the vapor seal chamber into the absorber. The first outlet of the absorber is connected to an exhaust pipe, which is used to discharge air. A lithium bromide solution is provided inside the absorber, which is used to absorb the water vapor.

2. The steam seal extraction system according to claim 1, characterized in that, The steam turbine unit includes: A steam turbine, wherein a first end of the steam turbine is provided with a multi-stage first steam seal, and a first steam seal cavity is formed between adjacent first steam seals, the first steam seal cavity being in communication with the interior of the steam turbine; a second end of the steam turbine is provided with a multi-stage second steam seal, and a second steam seal cavity is formed between adjacent second steam seals, the second steam seal cavity being in communication with the interior of the steam turbine; both the first steam seal cavity and the second steam seal cavity are connected to the extraction pipe; The balance chamber has its inlet connected to the first steam seal chamber and its outlet connected to the second steam seal chamber.

3. The steam seal extraction system according to claim 2, characterized in that, The first steam seal cavity includes: The first-stage steam sealing chamber is connected to the interior of the steam turbine, and the inlet of the balance chamber is connected to the first-stage steam sealing chamber; The secondary first steam seal chamber is connected to the primary first steam seal chamber, and the secondary first steam seal chamber is connected to the extraction pipe.

4. The steam seal extraction system according to claim 2, characterized in that, The second steam seal cavity includes: The first-stage second steam seal chamber is connected to the interior of the steam turbine, and the outlet of the balance chamber is connected to the first-stage second steam seal chamber; The secondary steam seal chamber is connected to the primary steam seal chamber, and the secondary steam seal chamber is connected to the extraction pipe.

5. The vapor sealing extraction system according to claim 1, characterized in that, The refrigeration subsystem includes: A refrigeration unit is used to generate water vapor and cool the surrounding environment, and the outlet of the refrigeration unit is connected to the second inlet of the absorber; The heating unit has its inlet connected to the second outlet of the absorber and its first outlet connected to the inlet of the refrigeration unit. The heating unit is used to heat the lithium bromide solution to generate saturated vapor, which enters the refrigeration unit.

6. The vapor seal extraction system according to claim 5, characterized in that, The refrigeration unit includes: A condenser, the inlet of which is connected to the first outlet of the heating unit, is used to condense the saturated steam to produce condensate. The first throttle valve is connected to the outlet of the condenser; An evaporator, wherein the inlet of the evaporator is connected to the first throttle valve, and the outlet of the evaporator is connected to the second inlet of the absorber; The condensate enters the evaporator after passing through the first throttling valve, forming water vapor.

7. The vapor sealing extraction system according to claim 6, characterized in that, The heating unit includes: A first conduit, the first end of which is connected to the second outlet of the absorber; A steam generator, the inlet of which is connected to the second end of the first pipeline, and the first outlet of which is connected to the inlet of the condenser, the steam generator being used to heat a lithium bromide solution to generate saturated steam.

8. The vapor sealing extraction system according to claim 7, characterized in that, The heating unit further includes a first pump, which is disposed in the first pipeline and is used to pump the lithium bromide solution in the absorber to the steam generator.

9. The steam seal extraction system according to claim 7, characterized in that, The heating unit also includes: The second pipeline has its two ends connected to the second outlet of the steam generator and the third inlet of the absorber, respectively, so that the lithium bromide solution can flow back from the steam generator to the absorber. The second throttle valve is installed in the second pipeline.

10. The steam seal extraction system according to claim 1, characterized in that, It also includes a second pump, which is disposed in the exhaust pipe.

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