阅读说明：本技术 一种两相自然循环一体化反应堆 (Two-phase natural circulation integrated reactor ) 是由 周喆 石雪垚 李精精 王辉 汪俊 孙婧 李汉辰 王贺南 雷宁博 蔡盟利 于 2020-04-14 设计创作，主要内容包括：本发明属于核反应堆技术领域,具体涉及一种两相自然循环一体化反应堆,包括压力容器(1)和压力容器(1)内的吊篮(3),位于吊篮(3)底部之内的堆芯(2),吊篮(3)内部位于堆芯(2)上方的空间为一回路堆芯出口腔室(7),还包括吊篮(3)顶部外围的与二回路连通的热交换区(5)；堆芯(2)产生的第一蒸汽经过一回路堆芯出口腔室(7)进入热交换区(5)将二回路提供的冷却水加热为第二蒸汽后转换为冷凝水并回流到堆芯(2),第二蒸汽输送至二回路。本发明将反应堆和蒸汽发生器集合在压力容器1内,简化了设备,取消了主泵、一回路管道、稳压器等设计,减少发生能动设备故障和破口的风险,避免放射性产物对二回路设备的影响。(The invention belongs to the technical field of nuclear reactors, and particularly relates to a two-phase natural circulation integrated reactor which comprises a pressure vessel (1), a hanging basket (3) in the pressure vessel (1), a reactor core (2) positioned in the bottom of the hanging basket (3), a space above the reactor core (2) in the hanging basket (3) is a primary loop reactor core outlet chamber (7), and a heat exchange region (5) which is arranged on the periphery of the top of the hanging basket (3) and is communicated with a secondary loop; the first steam generated by the reactor core (2) enters the heat exchange region (5) through the outlet chamber (7) of the primary reactor core to heat the cooling water provided by the secondary circuit into second steam, and then the second steam is converted into condensed water and flows back to the reactor core (2), and the second steam is conveyed to the secondary circuit. According to the invention, the reactor and the steam generator are integrated in the pressure vessel 1, so that the equipment is simplified, the designs of a main pump, a loop pipeline, a voltage stabilizer and the like are omitted, the risks of active equipment failure and breakage are reduced, and the influence of radioactive products on the two-loop equipment is avoided.)

1. A two-phase natural circulation integrated reactor comprises a pressure vessel (1) and is characterized in that: the reactor core is characterized by further comprising a hanging basket (3) arranged in the pressure vessel (1), a reactor core (2) positioned in the bottom of the hanging basket (3), a space above the reactor core (2) in the hanging basket (3) is a primary reactor core outlet chamber (7), and a heat exchange region (5) which is positioned on the periphery of the top of the hanging basket (3) and is communicated with a secondary circuit; the first steam generated by the core (2) enters the heat exchange area (5) through the primary core outlet chamber (7) to heat the cooling water provided by the secondary loop into second steam, and then the second steam is converted into condensed water and flows back to the core (2), and the second steam is conveyed to the secondary loop.

2. The two-phase natural circulation integrated reactor as claimed in claim 1, wherein: the reactor core (2) is composed of a plurality of accident fault-tolerant fuel assemblies.

3. The two-phase natural circulation integrated reactor as claimed in claim 2, wherein: the condensed water is collected to the bottom of the pressure vessel (1) and flows back into the core (2) from the bottom of the hanging basket (3).

4. A two-phase natural circulation integrated reactor as claimed in claim 3, wherein: the side of the hanging basket (3) is of a sealing structure, and the hanging basket (3) is provided with a heat insulation layer.

5. The two-phase natural circulation integrated reactor as claimed in claim 4, wherein: the heat exchange area (5) is provided with a two-loop water supply inlet (8) communicated with the two loops and used for conveying the cooling water provided by the two loops into the heat exchange area (5).

6. The two-phase natural circulation integrated reactor as claimed in claim 5, wherein: the reactor also comprises a control rod driving mechanism (4) which can be automatically inserted into the reactor core (2) under the condition of power failure caused by accidents to realize shutdown operation.

7. The two-phase natural circulation integrated reactor as claimed in claim 6, wherein:

an isolation layer (11) is arranged in the pressure vessel (1), the pressure vessel (1) is divided into an upper vessel body and a lower vessel body which are sealed and isolated from each other, and the outlet cavity (7) of the primary loop reactor core penetrates through the isolation layer (11);

a primary circuit descending annular cavity (6) is formed by the space between the side wall of the lower container body and the hanging basket (3), the primary circuit descending annular cavity (6) is communicated with the bottom of the hanging basket (3), and the condensed water is collected to the bottom of the pressure container (1) through the primary circuit descending annular cavity (6) and flows back into the reactor core (2) from the bottom of the hanging basket (3);

the heat exchange area (5) is located in the upper container body, and the heat exchange area (5) is used for exchanging heat between the first steam and the cooling water, heating the cooling water into the second steam, and simultaneously condensing the first steam into the condensed water.

8. The two-phase natural circulation integrated reactor of claim 7, wherein:

said second steam enters said upper vessel body through the top of said heat exchange zone (5); the condensed water flows into the loop descending ring cavity (6) from the bottom of the heat exchange area (5);

the upper container body is an upper seal head (10) of the pressure container; the top of the pressure vessel (1) is provided with two loops of steam outlets (9), and the two loops of steam outlets (9) are communicated with the upper seal head (10) of the pressure vessel and used for conveying the second steam to the two loops;

the control rod drive mechanism (4) is positioned below the core (2) and can be inserted into the core (2) from bottom to top.

9. The two-phase natural circulation integrated reactor of claim 8, wherein: the vertical width of the longitudinal section of the hanging basket (3) is consistent and is rectangular; the top of the hanging basket (3) is sealed, and the side surface of the top of the hanging basket (3) is provided with a channel (12) communicated with the heat exchange area (5) for the first steam to enter the heat exchange area (5) from the outlet chamber (7) of the primary core.

10. The two-phase natural circulation integrated reactor of claim 8, wherein: the vertical widths of the longitudinal sections of the hanging baskets (3) are different, the width of the upper part is smaller than that of the lower part, the part of the longitudinal section between the top end of the reactor core (2) and the isolation layer (11) is conical, and the rest part of the longitudinal section is rectangular; and the top of the hanging basket (3) is provided with a ventilation structure (13), and the ventilation structure (13) is communicated with the heat exchange region (5) and used for enabling the first steam to enter the heat exchange region (5) from the outlet chamber (7) of the primary reactor core.

11. The two-phase natural circulation integrated reactor as claimed in claim 6, wherein:

the vertical width of the longitudinal section of the hanging basket (3) is consistent and is rectangular;

the upper container body is an upper seal head (10) of the pressure container; the first steam enters the upper head (10) of the pressure vessel from the outlet chamber (7) of the primary reactor core and then flows into the top of the heat exchange region (5) for heat exchange;

the heat exchange area (5) is provided with a secondary loop steam outlet (9) communicated with the secondary loop, and the secondary steam is conveyed to the secondary loop through the secondary loop steam outlet (9); the condensed water flows into the loop descending ring cavity (6) from the bottom of the heat exchange area (5);

the control rod driving mechanism (4) is positioned above the reactor core (2), penetrates through the outlet chamber (7) of the reactor core of the primary circuit and can be inserted into the reactor core (2) from top to bottom.

Technical Field

The invention belongs to the technical field of nuclear reactors, and particularly relates to a two-phase natural circulation integrated reactor.

Background

In a nuclear reactor system, a primary loop system and a secondary loop system are generally arranged, cooling water in the primary loop of the nuclear reactor is heated by a reactor core, heat is transferred to water in the secondary loop, and the water in the secondary loop forms steam to drive a turbine generator. Such design often needs to set up a series of corollary equipments such as main pump, a return circuit pipeline, stabiliser, steam generator outside the reactor and be used for the heat transfer of return circuit and two return circuits, causes whole reactor system too complicated.

Since the 21 st century, small reactors have attracted attention from countries around the world due to their advantages of low initial investment, short construction period, low requirements for equipment manufacture and transportation, and flexible application. Various types of small reactors are designed, for example, the ACP100 in china is a small integrated reactor using forced circulation, and the NuScale in the united states is a small integrated reactor using natural circulation. Although the occurrence of pipeline breakage accidents is reduced and the safety of the reactor is improved due to the integrated design of the small reactor, the reactor adopting forced circulation or natural circulation has the limitations. Forced circulation needs external energy, and current loss accidents can occur, while similar NuScale adopts single-phase natural circulation, and the driving force generated by density difference is limited, so that the power of the reactor is limited, and the economy of a small reactor is influenced.

The invention patent application with the application number of 201810522750.3 provides a flash evaporation driven full natural circulation integrated pressurized water reactor, and the coolant in the reactor core is subjected to flash evaporation due to pressure reduction under the condition of approaching the saturation temperature, so that two-phase natural circulation is realized. The design is limited because the coolant temperature can not exceed the saturation temperature, the temperature difference of the primary side and the secondary side is improved compared with the current reactor design, and the flash evaporation phenomenon per se has great limitation, so that the design is greatly limited in engineering application.

Disclosure of Invention

The method aims at the problems that forced circulation in the existing small reactor design needs to be driven by an external power supply, the driving force of single-phase natural circulation is limited, and the power of the reactor is limited. The invention aims to provide a two-phase natural circulation integrated reactor, which adopts a 2-loop design, wherein water and saturated steam or superheated steam exist in a primary loop at the same time, the natural circulation capacity of the reactor is improved by utilizing the driving force obtained by the huge density difference between the water and the steam, and meanwhile, the heat exchange efficiency between the primary loop and the secondary loop is improved by utilizing the larger temperature difference between the saturated steam or the superheated steam of the primary loop and the secondary loop, so that the power of the reactor can be designed to be higher.

In order to achieve the purpose, the invention adopts the technical scheme that the reactor comprises a pressure vessel, a hanging basket arranged in the pressure vessel, a reactor core positioned in the bottom of the hanging basket, a primary loop reactor core outlet chamber positioned in the space above the reactor core in the hanging basket, and a heat exchange area positioned on the periphery of the top of the hanging basket and communicated with a secondary loop, wherein the space above the reactor core is a primary loop reactor core outlet chamber; and the first steam generated by the core enters the heat exchange region through the outlet cavity of the primary core, the cooling water provided by the secondary loop is heated into second steam, the second steam is converted into condensed water and flows back to the core, and the second steam is conveyed to the secondary loop.

Further, the core is comprised of a plurality of sets of accident tolerant fuel assemblies.

Further, the condensed water collects at the bottom of the pressure vessel and flows back into the core from the bottom of the basket.

Further, the side of hanging flower basket is seal structure, the hanging flower basket has the insulating layer.

Furthermore, the heat exchange area is provided with a two-loop water supply inlet communicated with the two loops and used for conveying the cooling water provided by the two loops into the heat exchange area.

Further, the control rod driving mechanism can be automatically inserted into the reactor core under the condition of power failure caused by accidents, and the shutdown operation is realized.

Furthermore, an isolation layer is arranged in the pressure vessel, the pressure vessel is divided into an upper vessel body and a lower vessel body which are mutually sealed and isolated, and the outlet cavity of the primary loop reactor core penetrates through the isolation layer;

the interval between the side wall of the lower container body and the hanging basket forms a primary circuit descending ring cavity, the primary circuit descending ring cavity is communicated with the bottom of the hanging basket, and the condensed water is collected to the bottom of the pressure container through the primary circuit descending ring cavity and flows back to the reactor core from the bottom of the hanging basket;

the heat exchange area is located in the upper container body and used for carrying out heat exchange on the first steam and the cooling water, heating the cooling water into the second steam and simultaneously condensing the first steam into the condensed water.

Further, the second steam enters the upper vessel body through the top of the heat exchange zone; the condensed water flows into the loop descending ring cavity from the bottom of the heat exchange area;

the upper container body is an upper seal head of the pressure container; the top of the pressure container is provided with a secondary loop steam outlet which is communicated with the upper seal head of the pressure container and used for conveying the second steam to the secondary loop;

the control rod drive mechanism is positioned below the reactor core and can be inserted into the reactor core from bottom to top.

Furthermore, the vertical width of the longitudinal section of the hanging basket is consistent and is rectangular; the top of the hanging basket is sealed, and a channel communicated with the heat exchange area is arranged on the side face of the top of the hanging basket and used for enabling the first steam to enter the heat exchange area from the outlet cavity of the primary reactor core.

Further, the longitudinal sections of the baskets have different upper and lower widths, the upper width is smaller than the lower width, the part between the top end of the reactor core and the isolation layer in the longitudinal section is conical, and the rest part is rectangular; and the top of the hanging basket is provided with a ventilation structure, and the ventilation structure is communicated with the heat exchange region and used for enabling the first steam to enter the heat exchange region from the outlet chamber of the primary reactor core.

Furthermore, the vertical width of the longitudinal section of the hanging basket is consistent and is rectangular;

the upper container body is an upper seal head of the pressure container; the first steam enters the upper head of the pressure vessel from the outlet cavity of the primary reactor core and then flows into the top of the heat exchange area for heat exchange;

the heat exchange area is provided with a secondary loop steam outlet communicated with the secondary loop, and the second steam is conveyed to the secondary loop through the secondary loop steam outlet; the condensed water flows into the loop descending ring cavity from the bottom of the heat exchange area;

the control rod driving mechanism is located above the reactor core, penetrates through the outlet cavity of the reactor core of the primary circuit and can be inserted into the reactor core from top to bottom.

The invention has the beneficial effects that:

1. according to the two-phase natural circulation integrated reactor provided by the invention, the reactor and the steam generator (namely the heat exchange area 5) are integrated in the pressure vessel 1, so that the equipment is greatly simplified, the designs of a main pump, a loop pipeline, a voltage stabilizer and the like are omitted, the risks of active equipment failure and breakage are reduced, and the influence of radioactive products on the two-loop equipment can be avoided.

2. Not only realizes two-phase natural circulation, but also has higher gas phase temperature, thereby obtaining larger primary and secondary side temperature difference. Wherein, a loop is a two-phase natural circulation (the loop is completely contained in the lower container bodies of the hanging basket 3 and the pressure container 1), and a larger driving force is obtained by utilizing the huge density difference between water and steam, so that the natural circulation capacity of the reactor is improved, and the power level of the reactor is improved.

3. The reactor core 2 adopts accident fault tolerant fuel (ATF) and can bear higher temperature, so that saturated steam or superheated steam is obtained in the outlet chamber 7 of the reactor core of the primary circuit, the heat efficiency of the reactor is enhanced, and the heat exchange between the primary circuit and the secondary circuit is enhanced.

4. The cooling water supplied by the two circuits is heated to superheated steam, so that a steam-water separator and a steam drier are not required, and the thermal efficiency is improved.

5. By adopting the control rod driving mechanism 4 with failure safety, the control rod driving mechanism 4 can be automatically inserted into the reactor core 2 after losing restraint when power is lost, so that the reactor is stopped, and the inherent safety of the reactor is improved.

6. A primary circuit acts as a radioactive barrier for the reactor, so that conventional islands do not need to consider further nuclear radiation shielding issues.

Drawings

FIG. 1 is a schematic diagram of a first two-phase natural circulation integrated reactor according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a second two-phase natural circulation integrated reactor according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a third two-phase natural circulation integrated reactor according to an embodiment of the present invention;

in the figure: 1-a pressure vessel, 2-a reactor core, 3-a hanging basket, 4-a control rod driving mechanism, 5-a heat exchange area, 6-a loop descending ring cavity, 7-a loop reactor core outlet cavity, 8-a secondary loop water supply inlet, 9-a secondary loop steam outlet, 10-a pressure vessel upper end enclosure, 11-an isolation layer, 12-a channel and 13-a ventilation structure; arrows in the figure indicate the flow direction of the first steam, the second steam, the cooling water and the condensed water.

Detailed Description

The invention is further described below with reference to the figures and examples.

As shown in fig. 1, the reactor (the first type) with two-phase natural circulation provided by the invention comprises a pressure vessel 1, a hanging basket 3 arranged in the pressure vessel 1, a reactor core 2 positioned in the bottom of the hanging basket 3 (the reactor core 2 is positioned at the bottom of the pressure vessel 1), a primary reactor core outlet chamber 7 arranged in the space above the reactor core 2 in the hanging basket 3, and a heat exchange area 5 positioned at the periphery of the top of the hanging basket 3 and communicated with a secondary circuit; first steam (the first steam is saturated steam or superheated steam and comes from cooling water in the primary loop heated to boiling by the core 2) generated by the core 2 enters the heat exchange region 5 through the primary loop outlet chamber 7, the cooling water provided by the secondary loop is heated into second steam (the second steam is superheated steam) and then is converted into condensed water to be returned to the core 2, and the second steam is conveyed to the secondary loop.

The core 2 is made up of several groups of accident tolerant fuel assemblies (i.e., ATF fuel assemblies).

The condensed water condensed from the first steam is collected at the bottom of the pressure vessel 1, flows back from the bottom of the basket 3 into the core 2, and continues to be used as cooling water to participate in the generation of the first steam.

The side of the hanging basket 3 is a sealing structure, the hanging basket 3 is provided with a heat insulation layer, and heat exchange between high-temperature gas in the hanging basket 3 and low-temperature liquid outside the hanging basket 3 is reduced.

The heat exchange area 5 is provided with a two-loop feed water inlet 8 communicated with the two loops for delivering cooling water provided by the two loops into the heat exchange area 5.

And the control rod driving mechanism 4 can be automatically inserted into the reactor core 2 to realize shutdown operation in case of power failure caused by accident.

An isolation layer 11 is arranged in the pressure vessel 1, the pressure vessel 1 is divided into an upper vessel body and a lower vessel body which are mutually sealed and isolated, and the outlet chamber 7 of the primary loop reactor core passes through the isolation layer 11;

the interval between the side wall of the lower container body and the hanging basket 3 forms a primary circuit descending ring cavity 6, the primary circuit descending ring cavity 6 is communicated with the bottom of the hanging basket 3, and condensed water obtained by condensing the first steam is collected to the bottom of the pressure container 1 through the primary circuit descending ring cavity 6 and flows back to the reactor core 2 from the bottom of the hanging basket 3;

the heat exchange area 5 is arranged in the upper container body, the heat exchange area 5 is used for carrying out heat exchange on the first steam and the cooling water, the cooling water is heated into second steam, meanwhile, the first steam is condensed into condensed water, and only heat exchange is carried out between the first steam and the cooling water, so that the first steam and the cooling water are not in direct contact.

The second steam enters the upper vessel body through the top of the heat exchange zone 5; the bottom of the heat exchange area 5 is communicated with a primary circuit descending ring cavity 6, and condensed water flows into the primary circuit descending ring cavity 6 from the bottom of the heat exchange area 5;

the upper container body is an upper seal head 10 of the pressure container and is used as a two-loop air cavity; the top of the pressure container 1 is provided with a secondary loop steam outlet 9, and the secondary loop steam outlet 9 is communicated with an upper seal head 10 of the pressure container and used for conveying secondary steam to the secondary loop;

the control rod drive mechanisms 4 are located below the core 2 and can be inserted into the core 2 from below to above.

The vertical width of the longitudinal section of the hanging basket 3 is consistent and is rectangular; the top of the basket 3 is sealed, and the side surface of the top of the basket 3 is provided with a channel 12 communicated with the heat exchange area 5 for the first steam to enter the heat exchange area 5 from the outlet chamber 7 of the primary reactor core.

The reactor core 2, the primary reactor core outlet chamber 7, the channel 12, the part of the heat exchange region 5 for passing and condensing the first steam, and the primary descending ring cavity 6 belong to a primary loop. The two-loop feed water inlet 8, the part for passing through cooling water and heating the cooling water into second steam in the heat exchange area 5, the pressure container upper end enclosure 10 and the two-loop steam outlet 9 belong to two loops.

The coolant (cooling water in the primary loop) boils and evaporates in the core 2, becomes first steam, passes through the primary loop core outlet chamber 7 and the heat exchange region 5, and performs heat exchange with the cooling water provided by the secondary loop in the heat exchange region 5, and the first steam is cooled into liquid condensate water, enters the primary loop descending ring cavity 6, and enters the core 2 from the bottom of the core 2. The cooling water provided by the two loops enters from a two-loop feed water inlet 8, is heated to be second steam in the heat exchange area 5, and the second steam flows into an upper seal head 10 of the pressure vessel and flows out from a two-loop steam outlet 9. Because the upper end enclosure 10 of the pressure vessel is positioned in the two loops, the control rod driving mechanism 4 with the fault safety is inserted into the reactor core 2 from bottom to top, and when accidents such as power loss occur, the control rod driving mechanism 4 can be reset by using mechanical designs such as springs and the like and is completely inserted into the reactor core 2, so that the safe shutdown of the reactor is realized.

As shown in fig. 2, the present invention further provides a second two-phase natural circulation integrated reactor, which is different from the first two-phase natural circulation integrated reactor as follows: the upper width and the lower width of the longitudinal section of the hanging basket 3 are different, the upper width is smaller than the lower width, the part of the longitudinal section from the top of the reactor core 2 to the separation layer 11 is conical, and the rest part is rectangular; the top of the basket 3 is provided with a ventilation structure 13, and the ventilation structure 13 is communicated with the heat exchange area 5 and used for enabling the first steam to enter the heat exchange area 5 from the outlet chamber 7 of the primary reactor core.

The reactor core 2, the primary reactor core outlet chamber 7, the ventilation structure 13, the part of the heat exchange region 5 for passing and condensing the first steam, and the primary descending ring cavity 6 belong to a primary loop. The two-loop feed water inlet 8, the part for passing through cooling water and heating the cooling water into second steam in the heat exchange area 5, the pressure container upper end enclosure 10 and the two-loop steam outlet 9 belong to two loops.

The solution in fig. 2 is a possible variant of the solution in fig. 1, mainly considering that the first steam is removed from the inside, and the number of heat transfer tubes in the heat exchange zone 5 needs to be such that the heat exchange is better achieved. The solution of fig. 2 enables more heat transfer tubes to be laid down in the heat exchange zone 5 than in the solution of fig. 1.

As shown in fig. 3, the present invention further provides a third two-phase natural circulation integrated reactor, which is different from the first two-phase natural circulation integrated reactor as follows:

the vertical width of the longitudinal section of the hanging basket 3 is consistent and is rectangular;

the upper container body is an upper seal head 10 of the pressure container and is used as a primary loop air cavity; the first steam enters an upper head 10 of the pressure vessel from an outlet chamber 7 of the primary reactor core and then flows into the top of the heat exchange area 5 for heat exchange;

the heat exchange area 5 is provided with a secondary loop steam outlet 9 communicated with the secondary loop, and the second steam is conveyed to the secondary loop through the secondary loop steam outlet 9; the bottom of the heat exchange area 5 is communicated with a primary circuit descending ring cavity 6, and condensed water flows into the primary circuit descending ring cavity 6 from the bottom of the heat exchange area 5;

the control rod drive mechanism 4 is located above the core 2, passes through the primary core exit chamber 7, and is insertable into the core 2 from top to bottom.

The reactor core 2, the primary loop reactor core outlet chamber 7, the pressure vessel upper head 10, the part for passing and condensing the first steam in the heat exchange area 5 and the primary loop descending ring cavity 6 belong to a primary loop. The two-loop feed water inlet 8, the part of the heat exchange area 5 for passing through the cooling water and heating to the second steam, and the two-loop steam outlet 9 belong to two loops.

The coolant (cooling water in the primary loop) boils and evaporates in the reactor core 2, becomes first steam, passes through the outlet chamber 7 of the primary loop reactor core, reaches the upper end enclosure 10 of the pressure vessel, then passes through the heat exchange area 5, and performs heat exchange with the cooling water provided by the secondary loop in the heat exchange area 5, and the first steam is cooled into liquid condensate water, enters the descending ring cavity 6 of the primary loop, and enters the reactor core 2 from the bottom of the reactor core 2. The cooling water provided by the two loops enters from the two loop feed water inlet 8 and is heated in the heat exchange area 5 to be the second steam, and the second steam flows out from the two loop steam outlet 9. The fail-safe control rod driving mechanism 4 is inserted into the reactor core 2 from top to bottom, and when accidents such as power loss occur, the control rod driving mechanism 4 can be completely inserted into the reactor core 2 by means of spring reset, gravity falling and the like, so that safe reactor shutdown is realized.

The device according to the present invention is not limited to the embodiments described in the specific embodiments, and those skilled in the art can derive other embodiments according to the technical solutions of the present invention, and also belong to the technical innovation scope of the present invention.