CN112595135A - Passive safety system for eliminating water hammer induced by steam condensation - Google Patents
Passive safety system for eliminating water hammer induced by steam condensation Download PDFInfo
- Publication number
- CN112595135A CN112595135A CN202011449991.3A CN202011449991A CN112595135A CN 112595135 A CN112595135 A CN 112595135A CN 202011449991 A CN202011449991 A CN 202011449991A CN 112595135 A CN112595135 A CN 112595135A
- Authority
- CN
- China
- Prior art keywords
- steam
- water hammer
- condensation
- eliminating
- safety system
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28B—STEAM OR VAPOUR CONDENSERS
- F28B9/00—Auxiliary systems, arrangements, or devices
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28B—STEAM OR VAPOUR CONDENSERS
- F28B9/00—Auxiliary systems, arrangements, or devices
- F28B9/10—Auxiliary systems, arrangements, or devices for extracting, cooling, and removing non-condensable gases
Abstract
The invention provides a passive safety system for eliminating water hammer induced by steam condensation. The twisted belt is arranged in the hole pipe through the snap ring, so that a steam-water mixture generated by the heat exchanger spirally flows upwards in a flow channel formed by the twisted belt and the hole pipe, and is directly contacted and condensed with seawater through the flow holes on the side surface and the top surface of the hole pipe. The steam is gradually condensed under the stirring action of the twisted belt, thereby playing a role in eliminating water hammer induced by steam condensation. The invention has the advantages that: the structure is simple, the water hammer caused by the condensation of steam on the pipeline and the seawater side can be eliminated simultaneously, the natural circulation capability of the passive safety system is improved, and the application range is wide; meanwhile, the invention is convenient and easy to improve and convenient for engineering application.
Description
Technical Field
The invention relates to a passive safety system for eliminating water hammer induced by steam condensation, belonging to the field of heat transfer science and hydrodynamics.
Background
In a floating nuclear power plant passive safety system, the ocean typically acts as the ultimate heat sink to absorb the excess heat. Under two-phase conditions, saturated steam generated by the heat exchanger inevitably comes into direct contact with the supercooled seawater. Due to the severe condensation, the seawater will flow back into the heat pipe. When the steam is surrounded by the seawater and forms a steam plug, the rapid condensation of the steam plug can cause the liquid columns at the two ends to collide violently, and steam condensation is generated to induce water hammer. The occurrence of water hammer can generate large pressure pulses and cause the pipeline to oscillate and even destroy the integrity of the system. To avoid condensation-induced water hammer phenomena caused by direct contact condensation, such passive systems are only allowed to operate at single phase or low exit gas void, which greatly limits the range of applications for passive safety systems.
In the prior art, methods for inhibiting and eliminating water hammer exist, the methods for eliminating the water hammer induced by steam condensation are all based on in-pipe water hammer elimination, and CN107013784A and CN107131383A respectively adopt a partition pipe type and a porous pipe type to inhibit the water hammer. The intermediate pipe type is to divide the pipeline into a plurality of flow passages to inhibit water hammer, but no measure for eliminating steam is provided, and only the condition that the water hammer does not appear in each branch pipeline is ensured. The multi-hole pipe type water hammer suppression measure has good effect of eliminating steam bubbles only under certain steam pressure, and the resistance of the multi-hole pipe is larger. The method achieves the aim of inhibiting the water hammer by changing the geometric structure in the pipeline. This increases the flow resistance of the system due to the addition of the abatement measures inside the pipeline. For a passive natural circulation system, the flow characteristics of the passive natural circulation system are sensitive to resistance characteristics, and the flow characteristics of the system are changed due to resistance change, so that the universality is not strong. Secondly, under the condition of high steam flow, the supercooled water in the pipeline can be heated by steam by the in-pipe elimination measure, so that the direct contact type condensation heat exchange coefficient is reduced, and the condition that the steam cannot be completely condensed in the pipeline exists. The small steam bubbles separated by the steam by the elimination measure can be re-polymerized at the downstream to form large bubbles, and after the large bubbles are contacted with the low-temperature seawater, the seawater can still flow back into the heat pipe section due to violent condensation. Thus, there is a potential for water hammer to occur in both the heat pipe section and the seawater. The invention adopts the elbow and the steam elimination device arranged at the outlet of the heat pipe section to change the flow direction, and divides the steam bubble into a plurality of small steam bubbles and gradually condenses with the seawater, thus fundamentally eliminating the water hammer induced by steam condensation in the system.
Disclosure of Invention
The invention aims to provide a passive safety system for eliminating water hammer induced by steam condensation, and the system creatively designs a measure for eliminating the water hammer induced by the steam condensation, solves the problem that the existing passive safety system generates the water hammer of the steam condensation under the condition of high air content, and widens the engineering application range of the system.
The purpose of the invention is realized as follows: the heat pipe section and the cold pipe section are provided with valves, and the end part of the heat pipe section penetrates through the wall surface of the floating platform and is connected with a steam removal device through an elbow.
The invention also includes such structural features:
1. the steam-eliminating device comprises a hole pipe connected with the elbow, and a tie arranged in the hole pipe through a clamping ring, wherein the tie divides the hole pipe into four spirally-rising spaces, the hole pipe is a cylindrical pipe, and the upper end surface and the outer surface of the cylindrical pipe are uniformly provided with flow holes.
2. The steam-water mixture generated by the heat exchanger passes through the heat pipe section and the elbow, the flow direction of the steam-water mixture is changed after the steam-water mixture passes through the elbow, the steam-water mixture enters the steam-removing device and is divided into four sub-flow channels by the twisted belt and flows upwards in a spiral manner, and the steam-water mixture is in direct contact condensation with seawater through the flow holes in the spiral ascending flowing process, so that the steam is completely condensed in the steam-removing device.
Compared with the prior art, the invention has the beneficial effects that: the invention is an improvement and innovation of the prior art, the ocean is adopted as a passive residual heat removal system of a final heat sink at present, and the system can only operate under the condition of single phase or low gas content for avoiding water hammer. In practical engineering application, the possibility of superposition of multiple accidents exists, so that the heat load of the heat exchanger is increased, and a large amount of steam is generated at the outlet of the heat exchanger. The steam and the seawater generate direct contact type condensation, the severe condensation can cause the seawater to flow backwards into the heat pipe section, and water hammer induced by the steam condensation can possibly occur, and the occurrence of the water hammer seriously threatens the safe operation of the passive safety system. The invention adopts the installation of an elbow and a steam elimination device at the seawater side to change the flow direction of the steam-water mixture. The twisted belt is adopted to be divided into a plurality of flow channels, and the flow mode is changed into spiral flow. The vapor-liquid mixture is condensed by direct contact with seawater through the flow holes on the surface of the perforated pipe during the spiral upward flow. In the condensation process, the steam bubbles can be divided into small steam bubbles by the flow holes, water hammer can not occur in the condensation of the small steam bubbles, and the flow of the system can not be influenced, so that the aims of eliminating steam and inhibiting the water hammer are fulfilled. In addition, the vertically installed steam-eliminating device can provide additional driving force for the passive safety system, and the natural circulation capacity of the original system is improved. Therefore, the invention can effectively eliminate the occurrence of water hammer in the passive safety system, broadens the application range of the system and has important engineering application value.
1. The invention adopts the design of the steam-eliminating device combining the twisted belt and the perforated pipe in the design of the passive safety system, and the design changes the flow direction of the steam-water mixture, thereby fundamentally eliminating the phenomenon of water hammer caused by steam condensation in a hot pipe section in the system.
2. The steam-water mixture at the outlet of the heat exchanger is directly contacted and condensed with the seawater through the flow holes on the surface of the perforated pipe, and the steam bubbles can be divided into small steam bubbles by the flow holes and gradually condensed. This greatly reduces pressure fluctuations caused by condensation of the vapor bubbles and effectively suppresses water hammer that may occur in the steam elimination device.
3. The twisted belt divides the flow channel of the steam-water mixture into four sub-flow channels and changes the flow mode from vertical upward flow to spiral upward flow. The spiral flow strengthens the turbidity stirring capability of the steam-water mixture, and further improves the condensation heat exchange capability of the seawater and the steam.
4. The steam is condensed on the surface of the perforated pipe, and pressure fluctuation caused by condensation basically has no influence on upward flow, so that the flow oscillation of the original passive safety system caused by the backflow of seawater to the heat pipe section is completely eliminated.
5. The steam-eliminating device vertically arranged in the seawater can provide additional driving force for the original passive safety system, and the natural circulation capacity of the system is further improved.
Drawings
FIG. 1 is a schematic view of the structure of the present invention.
FIG. 2 is a schematic view of the structure of the steam-removing device.
FIG. 3 is a schematic view of a twist belt structure and installation
FIG. 4 is a schematic view of a hole tube structure
The meanings of the symbols in the combination of the figures 1-4 are respectively as follows: 1. the heat exchanger comprises a heat exchanger body 2, a heat pipe section 3, a floating type platform wall surface 4, an elbow 5, a steam elimination device 6, a cold pipe section 7, an ocean 5-1, a twisted belt 5-2, a hole pipe 5-3, a clamping ring 5-4 and a flow hole.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.
With reference to fig. 1-4, the present invention comprises a heat exchanger 1, a hot pipe section 2, a floating platform wall 3, an elbow 4, a steam trap 5, a cold pipe section 6, and an ocean 7. The elbow 4 and the steam-consuming device 5 are located in the ocean 7 and the elbow 4 is welded to the floating platform wall 3. The steam eliminating device 5 is connected by a twisting belt 5-1, a hole pipe 5-2 and a clamping ring 5-3 in a certain mode and is vertically arranged at the upper part of the elbow 4. The torsion band 5-1 is arranged on the inner wall surface of the clamping ring 5-3, and the outer wall surface of the clamping ring 5-3 is welded on the inner wall surface of the hole pipe 5-2. The side and top of the perforated pipe are provided with flow holes 5-4, and the sum of the areas of all the flow holes is larger than the flow area of the heat pipe section, so as to reduce the flow resistance. The lower part of the hole pipe is through and is connected with the upper part of the elbow 4.
The steam-water mixture generated by the heat exchanger 1 enters a steam-removing device 5 through a heat pipe section 2 and an elbow 4. After the steam-water mixture passes through the elbow 4, the flow direction is changed. Then the mixture enters a steam elimination device 5, and the steam-water mixture enters the steam elimination device 5 and is divided into four sub-flow channels by a twisting belt 5-1 and flows upwards in a spiral mode. The surface of the perforated pipe 5-2 is provided with a plurality of flow holes 5-3, and the steam-water mixture is directly contacted and condensed with the seawater through the flow holes 5-3 in the spiral rising flow process, so that the steam is completely condensed in the steam-removing device 5. Due to the small size of the flow holes 5-3, the steam does not form large bubbles, thereby eliminating the occurrence of water hammer. In addition, the steam-water mixture flows spirally in the sub-flow channel formed by the twisted belt 5-1, the stirring effect of the steam-water mixture in the flow channel is enhanced, the steam is prevented from being gathered at the center of the perforated pipe 5-2, the steam-water mixture is promoted to flow towards the pipe wall of the perforated pipe 5-2, the condensation heat exchange of the steam and the supercooled water is further enhanced, and the steam is fully condensed in the steam elimination device 5. In addition, the elimination measure 5 is vertically installed in the sea 7, and the density difference formed by the steam-water mixture in the device and the external sea water can provide additional driving force for the non-energy safety system, so that the natural circulation capacity of the original system is improved.
It should be noted that the torsion band 5-1 has various types, and the present invention takes the coaxial crossing two torsion bands as an example, and the application principle is the same for other types of torsion band structures, and also belongs to the protection scope of the present invention.
A passive safety system for eliminating water hammer induced by steam condensation is installed by the following steps: firstly, a cold pipe section 6 and a heat pipe section 2 are respectively arranged at an inlet and an outlet of a heat exchanger 1, the other ends of the cold pipe section 6 and the heat pipe section 2 are connected with a floating platform wall surface 3, and an elbow 4 is connected with an outlet of the heat pipe section 2 and welded on the floating platform wall surface 3. The torsion strap 5-1 is fixed by a snap ring 5-3, and the snap ring 5-3 is welded on the inner wall surface of the hole pipe 5-2, as shown in fig. 3. The hole pipe 5-2 and the elbow 4 are connected together, and finally the passive safety system for eliminating the water hammer induced by steam condensation is obtained.
The specific operation process of the passive safety system for eliminating the water hammer induced by steam condensation is as follows:
when the system operates, the seawater in the heat exchanger 1 is heated to raise the temperature, natural circulation is started under the driving of the difference between the density of the seawater in the heat exchanger 1 and the density of the seawater in the ocean 7, and the seawater discharges the heat generated in the heat exchanger 1 into the ocean 7. When the heat load of the heat exchanger 1 is increased, the outlet of the heat exchanger can generate saturated steam-water mixture or superheated steam, the steam enters the elbow 4 in the sea 7 through the heat pipe section 2, the flow direction of the steam-water mixture is changed from horizontal flow to vertical upward flow, and the steam-water mixture enters the eliminating device 5. In the eliminator 5, the steam-water mixture flowing upward is divided into a plurality of sub-flow paths by the twisted belt 5-1 and spirally flows upward along the respective sub-flow paths. Under the action of the stirring of the twisted belt 5-1, steam flows towards the pipe wall of the perforated pipe 5-2. The steam in the steam-water mixture is directly contacted and condensed with the seawater in the ocean 7 through the flow holes 5-4 on the surface of the perforated pipe 5-2. Since the steam is divided into small bubbles by the flow space 5-4, the condensation does not cause large pressure fluctuations. Most of the steam is condensed in the steam trap 5 based on the above process, and the remaining steam flows into the ocean 7 through the flow holes 5-4 at the top of the perforated pipe 5-2 and is completely condensed. Thereby realizing the functions of eliminating steam and inhibiting water hammer.
The present invention is not limited to the specific embodiments described in the above examples, and it should be noted that, although the present invention has been described in detail with reference to the foregoing embodiments, a person skilled in the art may modify the foregoing technical solutions or make equivalent substitutions for some or all of the technical features, and such modifications or substitutions should also fall within the scope of the claims of the present invention.
In conclusion, the invention belongs to the field of heat transfer science and hydromechanics, and particularly relates to a passive safety system for eliminating water hammer induced by steam condensation. The device is used for eliminating the water hammer induced by steam condensation by installing an elbow and a steam elimination device on the seawater side. The twisted belt is arranged in the hole pipe through the snap ring, so that a steam-water mixture generated by the heat exchanger spirally flows upwards in a flow channel formed by the twisted belt and the hole pipe, and is directly contacted and condensed with seawater through the flow holes on the side surface and the top surface of the hole pipe. The steam is gradually condensed under the stirring action of the twisted belt, thereby playing a role in eliminating water hammer induced by steam condensation. The invention has the advantages that: the structure is simple, the water hammer caused by the condensation of steam on the pipeline and the seawater side can be eliminated simultaneously, the natural circulation capability of the passive safety system is improved, and the application range is wide; meanwhile, the invention is convenient and easy to improve and convenient for engineering application.
Claims (3)
1. A passive safety system for eliminating steam condensation induced water hammer, comprising: the heat pipe section and the cold pipe section are provided with valves, and the end part of the heat pipe section penetrates through the floating platform wall surface and is connected with a steam removal device through an elbow.
2. A passive safety system for eliminating steam condensation induced water hammer as claimed in claim 1, wherein: the steam-eliminating device comprises a hole pipe connected with the elbow, and a tie arranged in the hole pipe through a clamping ring, wherein the tie divides the hole pipe into four spirally-rising spaces, the hole pipe is a cylindrical pipe, and the upper end surface and the outer surface of the cylindrical pipe are uniformly provided with flow holes.
3. A passive safety system for eliminating steam condensation induced water hammer as claimed in claim 2, wherein: the steam-water mixture generated by the heat exchanger passes through the heat pipe section and the elbow, the flow direction of the steam-water mixture is changed after the steam-water mixture passes through the elbow, the steam-water mixture enters the steam-removing device and is divided into four sub-flow channels by the twisted belt and flows upwards in a spiral manner, and the steam-water mixture is in direct contact condensation with seawater through the flow holes in the spiral ascending flowing process, so that the steam is completely condensed in the steam-removing device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011449991.3A CN112595135A (en) | 2020-12-09 | 2020-12-09 | Passive safety system for eliminating water hammer induced by steam condensation |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011449991.3A CN112595135A (en) | 2020-12-09 | 2020-12-09 | Passive safety system for eliminating water hammer induced by steam condensation |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112595135A true CN112595135A (en) | 2021-04-02 |
Family
ID=75192074
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011449991.3A Pending CN112595135A (en) | 2020-12-09 | 2020-12-09 | Passive safety system for eliminating water hammer induced by steam condensation |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112595135A (en) |
Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1999048104A1 (en) * | 1998-03-19 | 1999-09-23 | Siemens Aktiengesellschaft | Device and method for running off steam |
| KR101576077B1 (en) * | 2014-07-23 | 2015-12-10 | 한국원자력연구원 | Passive residual heat removal system and nuclear power plant having the same |
| CN106402567A (en) * | 2016-08-27 | 2017-02-15 | 泰州学院 | Underwater anti-blocking and resistance-reducing elbow structure |
| CN107013784A (en) * | 2017-06-14 | 2017-08-04 | 西安交通大学 | Condense water hammer restraining device and suppression system |
| CN107131383A (en) * | 2017-06-14 | 2017-09-05 | 西安交通大学 | Condense water hammer and suppress structure and suppression system |
| CN107210071A (en) * | 2014-12-04 | 2017-09-26 | 原子能技术科学研究设计院股份公司 | Passive heat removal system inside containment |
| CN107833641A (en) * | 2017-10-10 | 2018-03-23 | 中国船舶重工集团公司第七〇九研究所 | A kind of marine PWR seawater cools down Passive residual heat removal system |
| CN109273112A (en) * | 2018-09-13 | 2019-01-25 | 中国核动力研究设计院 | A kind of direct cooling passive residual heat removal system of anti-gravity direction flowing |
| CN109340501A (en) * | 2018-12-10 | 2019-02-15 | 哈尔滨工程大学 | A kind of steam condensation induction water hammer cancellation element based on fixed twisted strip |
| CN109595422A (en) * | 2018-12-10 | 2019-04-09 | 哈尔滨工程大学 | A kind of steam condensation induction water hammer cancellation element based on rotary twisted strip |
| CN110792871A (en) * | 2019-10-23 | 2020-02-14 | 西安交通大学 | Stepped pipeline device for weakening strength of condensed water hammer |
| CN211232052U (en) * | 2019-10-31 | 2020-08-11 | 西安唐泰节能环保科技有限公司 | Water hammer eliminator |
-
2020
- 2020-12-09 CN CN202011449991.3A patent/CN112595135A/en active Pending
Patent Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1999048104A1 (en) * | 1998-03-19 | 1999-09-23 | Siemens Aktiengesellschaft | Device and method for running off steam |
| KR101576077B1 (en) * | 2014-07-23 | 2015-12-10 | 한국원자력연구원 | Passive residual heat removal system and nuclear power plant having the same |
| CN107210071A (en) * | 2014-12-04 | 2017-09-26 | 原子能技术科学研究设计院股份公司 | Passive heat removal system inside containment |
| CN106402567A (en) * | 2016-08-27 | 2017-02-15 | 泰州学院 | Underwater anti-blocking and resistance-reducing elbow structure |
| CN107013784A (en) * | 2017-06-14 | 2017-08-04 | 西安交通大学 | Condense water hammer restraining device and suppression system |
| CN107131383A (en) * | 2017-06-14 | 2017-09-05 | 西安交通大学 | Condense water hammer and suppress structure and suppression system |
| CN107833641A (en) * | 2017-10-10 | 2018-03-23 | 中国船舶重工集团公司第七〇九研究所 | A kind of marine PWR seawater cools down Passive residual heat removal system |
| CN109273112A (en) * | 2018-09-13 | 2019-01-25 | 中国核动力研究设计院 | A kind of direct cooling passive residual heat removal system of anti-gravity direction flowing |
| CN109340501A (en) * | 2018-12-10 | 2019-02-15 | 哈尔滨工程大学 | A kind of steam condensation induction water hammer cancellation element based on fixed twisted strip |
| CN109595422A (en) * | 2018-12-10 | 2019-04-09 | 哈尔滨工程大学 | A kind of steam condensation induction water hammer cancellation element based on rotary twisted strip |
| CN110792871A (en) * | 2019-10-23 | 2020-02-14 | 西安交通大学 | Stepped pipeline device for weakening strength of condensed water hammer |
| CN211232052U (en) * | 2019-10-31 | 2020-08-11 | 西安唐泰节能环保科技有限公司 | Water hammer eliminator |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102282628B (en) | Reactor vessel coolant deflector shield | |
| US3811498A (en) | Industrial technique | |
| CN112595135A (en) | Passive safety system for eliminating water hammer induced by steam condensation | |
| US5491730A (en) | Cooling system for primary containment vessel in nuclear power plant and component for use in said cooling system | |
| CA1161373A (en) | Stacked re-entrant arm vapor-liquid separator | |
| CN101551205A (en) | Spiral fin self-supporting heat exchanger | |
| KR20170039202A (en) | Deaerator (variants) | |
| JPS61250406A (en) | Feedwater heater for steam generator | |
| Zhang et al. | Experimental study on the effect of an expanding conjunction between a spilling basin and the downstream channel on the height after jump | |
| CN203132413U (en) | Heat exchanger tube bundle with reinforced heat transfer | |
| CN110792871B (en) | Stepped pipeline device for weakening strength of condensed water hammer | |
| JPS5944693A (en) | Reactor | |
| Xu et al. | Flow patterns and transition criteria in boiling water-cooled packed bed reactors | |
| RU2660120C1 (en) | Device for cleaning liquid from gas impurities (de-aerator, degasifier evaporator) | |
| RU2320035C1 (en) | Nuclear power unit | |
| JP3970001B2 (en) | Water heater | |
| Coad | Steam hammer: causes and cures | |
| JP2002139202A (en) | Steam/liquid separation structure in steam boiler | |
| CN206801965U (en) | One kind improves low-pressure heater and drainage pump anti-cavitation performance device | |
| RU2082229C1 (en) | Volume compensation system | |
| JP2963586B2 (en) | Steam generator | |
| JP2010164372A (en) | Cooling installation for reactor containment vessel | |
| JPH06142424A (en) | Vapor/liquid separator | |
| Eisinger et al. | Effect of tube-to-tube ties on fluidelastic instability of tube arrays exposed to crossflow | |
| RU2247434C1 (en) | Reactor flooding passive system water tank |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20210402 |
|
| RJ01 | Rejection of invention patent application after publication |