CN214624452U - Novel reactor based on double-layer pipeline technology - Google Patents

Abstract

The utility model relates to the technical field of nuclear power plant system equipment, in particular to a novel reactor based on double-layer pipeline technology, which comprises a loop system and a safety injection system, wherein the loop system at least comprises a pressure vessel and a steam generator for placing a reactor core, the pressure vessel is communicated with the steam generator through a hot pipe section and a cold pipe section to form a coolant circulation loop; the heat pipe section and/or the cold pipe section are/is a double-layer sleeve, a gap is reserved between two layers of pipelines of the double-layer sleeve, and the double-layer sleeve is provided with a pressure sensor for monitoring pressure change in the gap. Furthermore, the bottom of the pressure stabilizer of the loop system is communicated with the heat pipe section through the fluctuation pipe, the top of the pressure stabilizer is communicated with the cold pipe section through the spray pipe, and the fluctuation pipe and the spray pipe can also adopt double-layer sleeves. The utility model discloses can reduce reactor protection system's designing requirement effectively, simplify the system configuration, improve the economic nature and the fail safe nature of reactor.

Description

Novel reactor based on double-layer pipeline technology

Technical Field

The utility model relates to a nuclear power plant system equipment technical field, concretely relates to novel reactor based on double-deck pipeline technique.

Background

Most of commercial reactors in service today are light water reactors, which are classified into pressurized water reactors and boiling water reactors. The boiling water reactor adopts a loop, and the coolant is directly boiled in the reactor core to generate steam to drive the steam turbine to generate power. The pressurized water reactor is provided with two loops, one loop is in a high-temperature and high-pressure state, the pressure of the loop is usually more than 150 atmospheric pressures, and cooling water does not boil; the first loop and the second loop transfer the heat of the first loop to the second loop through the steam generator, and the coolant of the second loop boils at the secondary side of the steam generator to generate steam and then drive the steam turbine to generate power. The pressurized water reactor has higher safety compared with a boiling water reactor, so most of the active second and third generation reactors are pressurized water reactors.

The pressurized water reactor loop mainly comprises a pressure vessel, a steam generator, a pressure stabilizer, and a pipeline and a protection system which are connected with each other. Because a loop operating pressure and coolant temperature are very high, when the great connecting tube of internal diameter takes place to break the accident (including reactor trunk line, surge pipe, shower etc.), will cause serious a loop coolant to lose, make reactor core cooling not enough, the high temperature coolant that jets out simultaneously carries a large amount of heats, produce the flash distillation in containment and reactor factory building, make ambient pressure rise fast, threaten the structural integrity of containment and factory building, produce the risk that the radioactivity excess leaked. The equivalent diameter is greater than the breach of 9.5mm, three kinds of breachs, namely big, medium and little, and the coolant that the reactor loses can not be supplemented through filling the pump, need rely on the safety injection system to carry out the moisturizing to the reactor, otherwise the reactor core will face naked, the damaged risk of melting even of fuel assembly.

In order to protect a primary loop coolant from being sufficiently cooled, a fuel assembly is not damaged, and the pressure of a containment vessel and a reactor plant does not exceed the limit, a safety injection system, a containment vessel spraying system, a blasting pressure relief system and other protection systems are arranged in a nuclear power plant. The safe injection system consists of three subsystems of high-pressure safe injection, medium-pressure safe injection and low-pressure safe injection. According to the depressurization condition of the reactor coolant caused by accidents, when a primary circuit large-break loss of coolant accident happens, the high-pressure safety injection system injects water into the reactor core so as to submerge and cool the reactor core again and limit the temperature rise of the fuel rods. Meanwhile, in order to improve the safety margin of the reactor, a redundant protection system is generally required to be arranged, and the capacity of the protection system is conservatively improved, so that the economy of the nuclear power plant is sacrificed, and the cost of the nuclear power plant and the complexity and difficulty of construction are increased.

The larger the break of a primary circuit is, the larger the mass-energy release is, the more serious the accident consequence is, and the higher the requirement on the protection system is. Therefore, in order to improve both the economy and safety of a pressurized water reactor nuclear power plant, it is necessary to limit the size of the breach of the primary reactor, the smaller the size, the better.

SUMMERY OF THE UTILITY MODEL

The to-be-solved technical problem of the utility model lies in that, a novel reactor based on double-deck pipeline technique is provided.

The utility model provides a technical scheme that its technical problem adopted is: constructing a novel reactor based on a double-layer pipeline technology, which comprises a loop system and a safety injection system, wherein the loop system at least comprises a pressure vessel for placing a reactor core and a steam generator, and the pressure vessel is communicated with the steam generator through a heat pipe section and a cold pipe section to form a coolant flow passage loop; the heat pipe section and/or the cold pipe section are/is a double-layer sleeve, a gap is reserved between two layers of pipelines of the double-layer sleeve, and the double-layer sleeve is provided with a pressure sensor for monitoring pressure change in the gap.

Preferably, the reactor further comprises a primary circuit water replenishing tank arranged above the pressure container, and the water inlet and the water outlet are respectively communicated with the hot pipe section and the cold pipe section by adopting first connecting pipes.

Preferably, the first connecting pipe is a double-layer sleeve; and the primary loop water supplementing tank is filled with low-temperature boron-containing water.

Preferably, an isolation valve is arranged on the first connecting pipe; the first connecting pipe has an inner diameter greater than 50 mm.

Preferably, the safety injection system comprises a low-pressure safety injection assembly, the low-pressure safety injection assembly comprises a low-pressure safety injection pump and a safety injection water tank, the safety injection water tank is communicated with the cold pipe section through a second connecting pipe, and the low-pressure safety injection pump is installed on the second connecting pipe;

wherein, the safety injection water tank is filled with low-temperature boron-containing water, and the second connecting pipes are provided with isolating valves.

Preferably, an isolation valve and a check valve are connected in series between the low-pressure safety injection pump and the cold pipe section.

Preferably, the second connecting pipe adopts a double-layer sleeve in the pipe section between the check valve and the cold pipe section.

Preferably, the second connecting pipe is further provided with a branch interface connected to a waste heat discharge system for discharging waste heat.

Preferably, the reactor is also provided with a voltage stabilizer; the bottom of the pressure stabilizer is communicated with the heat pipe section through a fluctuation pipe, and the top of the pressure stabilizer is communicated with the cold pipe section through a spray pipe.

Preferably, the surge pipe and/or the shower pipe are double-layer sleeves.

Preferably, the double-layer sleeve is a pipeline with the inner diameter larger than 50mm and is positioned inside the containment vessel of the reactor.

Preferably, the two pipelines of the double-layer sleeve are concentrically arranged, the gap distance between the two pipelines is 5mm, and the gap is filled with normal-pressure dry air.

Preferably, the supporting bodies are uniformly distributed and fixed between the two layers of pipelines of the double-layer sleeve.

Implement the utility model discloses a novel reactor based on double-deck pipeline technique has following beneficial effect: the utility model adopts the design of double-layer sleeve pipes for the heat pipe section and/or the cold pipe section which are flowed with coolant in a loop system, and a gap is left between the two layers of pipelines of the double-layer sleeve pipes, thereby eliminating the possibility that the conventional reactor can break the large and medium loops of the loop pipeline; meanwhile, a pressure sensor is arranged in the gap of the double-layer pipeline to monitor pressure change in the gap, and whether the inner-layer pipeline is broken or not is judged in time. If the inner layer pipeline is broken, the outer layer pipeline can be used as a new pressure boundary to ensure the normal operation and radioactive containment of the reactor, and meanwhile, a gap pressure high protection signal is triggered to enable an operator to recognize the position where the broken opening occurs as soon as possible, so that corresponding protection measures are taken to ensure the safety of the reactor.

Further, the utility model discloses on the configuration basis that adopts double-deck pipeline, the safe injection system of this reactor comprises a return circuit moisturizing case and low pressure ann notes system, has the characteristic that active and passive combined together, has cancelled the high pressure and the middling pressure ann notes system of conventional reactor, has reduced redundant demand and ann notes capacity demand, improves the economic nature of nuclear power plant and fail safe nature.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.

FIG. 1 is a schematic diagram of an embodiment of the novel reactor of the present invention based on double-layer piping technology;

fig. 2 is a schematic cross-sectional view of a double-layer pipeline of an embodiment of the novel reactor based on double-layer pipeline technology of the present invention;

the reference numerals in the drawings denote: 1-a pressure vessel; 2-a steam generator; 3-a heat pipe section; 4-a cold pipe section; 5-double-layer sleeve; 6-a pressure sensor; 7-a primary circuit water replenishing tank; 8-a first connection pipe; 9-low pressure safety injection pump; 10-safety water injection tank; 11-a second connecting tube; 12-an isolation valve; 13-a check valve; 14-the main pump; a voltage stabilizer-15; surge tube-151; a shower-152; 501-clearance; 502-support.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the drawings in the embodiments of the present invention are combined below to clearly and completely describe the technical solutions in the embodiments of the present invention. It is to be understood that the embodiments described are only some of the embodiments of the present invention, and not all of them. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

The present invention will be further described with reference to the following examples.

Examples

Referring to fig. 1, a main body of the reactor belongs to a third-generation pressurized water reactor; of course other types of reactors are possible. The operating power, operating parameters and the like of the reactor are similar to those of the existing commercial third-generation reactor, and the reactor comprises a loop system, a safety injection system and the like. The loop system at least comprises a pressure vessel 1 for placing a reactor core and a steam generator 2, wherein the pressure vessel 1 is communicated with the steam generator 2 through a hot pipe section 3 and a cold pipe section 4 to form a coolant flow passage loop; in order to improve the stability of operation, the loop system in this embodiment is provided with three sets of circulation loops; of course, more sets may be provided. Wherein, a main pump 14 for pressurizing is arranged on the heat pipe section 3 of each group of the circulation loops. Only two circuit systems are shown in fig. 1. The pressure vessel 1 is loaded with fuel assemblies to form a core. The main pump 14 pressurizes and drives coolant in a loop to continuously transfer core internal fuel cracking heat to the steam generator 2.

Further, the reactor is provided with a voltage stabilizer 15 for performing voltage stabilization control on a loop. The bottom of the pressurizer 15 is communicated with the hot pipe section 3 through a surge pipe 151, and the top of the pressurizer is communicated with the cold pipe section 4 through a spray pipe 152. Wherein, the surge pipe 151 and/or the shower pipe 152 may also adopt a double-layer sleeve.

In a loop system, coolant flows through the heat pipe section and/or the cold pipe section, a large-diameter pipeline can be adopted, the large-diameter pipeline is a double-layer sleeve 5, a gap 501 is reserved between the two layers of pipelines of the double-layer sleeve 5, and a pressure sensor 6 for monitoring pressure change in the gap 501 is arranged outside the double-layer sleeve 5.

Referring to fig. 2, the large-diameter pipeline is a pipeline with an inner diameter greater than 50mm, and the large-diameter pipeline is located inside a containment vessel of the reactor. The distance of a gap 501 between the double-layer sleeves 5 is 5mm, normal-pressure dry air is filled in the gap 501, and the designed operating pressure of each layer of pipeline is the same and is equal to the operating pressure of the reactor. Furthermore, the supporting bodies 502 are uniformly distributed and fixed between the two layers of pipelines of the double-layer sleeve 5, and the supporting bodies 502 not only play a role in supporting and fixing the two pipelines, but also can effectively improve the rigidity of the whole double-layer sleeve 5.

In the primary circuit of the present embodiment, the double-layered piping is mainly used at the hot pipe section 3, the cold pipe section 4, and the surge pipe 151 and the shower pipe 152 for communicating the pressurizer 15. The double-layer pipeline can independently bear the operating pressure and temperature of a loop, the pressure of the gap 501 is very low even lower than the environmental pressure in normal operation, and meanwhile, the gap 501 of the double-layer pipeline is small, so that the possibility that the inner pipeline breaks and collides to cause the outer pipeline to break is eliminated, the double-layer pipeline cannot simultaneously break in design, and the occurrence of pipeline breakage accidents is avoided.

Meanwhile, a gap 501 pressure sensor 6 is installed in each section of double-layer pipeline gap 501, and the sensor transmits measured pressure data to a main control room to monitor pressure change in the gap 501 in real time. Monitoring principle: under normal operating conditions, the pressure in the gap 501 is about 1 atmosphere (or negative pressure state); when the inner layer pipeline has a breach accident, the coolant leaks to the gap 501, so that the pressure in the gap 501 is greatly increased to be more than the magnitude of MPa. Therefore, whether the inner layer pipeline is damaged or not and the position of the broken opening can be identified by monitoring the pressure change of the gap 501, and the detection is used as the basis for an operator to implement the reactor protection action or trigger the automatic protection action.

The reactor of the embodiment also comprises a loop water replenishing tank 7 of the passive safety injection system, and the active safety injection system comprises a low-pressure safety injection assembly. A loop water replenishing tank 7 is arranged above the pressure container 1, and a water inlet and a water outlet of the loop water replenishing tank are respectively communicated with the hot pipe section 3 and the cold pipe section 4 by adopting a first connecting pipe 8.

The low-pressure safety injection assembly comprises a low-pressure safety injection pump 9 and a safety injection water tank 10, the safety injection water tank 10 is communicated with the cold pipe section 4 through a second connecting pipe 11, and the low-pressure safety injection pump 9 is installed on the second connecting pipe 11; wherein, a loop water replenishing tank 7 and a safety injection water tank 10 are used for containing low-temperature boron-containing water, and the first connecting pipe 8 and the second connecting pipe 11 are both provided with isolating valves 12. Further, a sub-interface may be further disposed on the second connecting pipe 11 of the safety injection tank 10, and may be connected to a waste heat removal system (RHR), and when the safety injection function is not required to be performed, the sub-interface may be connected to the waste heat removal system to perform a preheating discharge function.

The primary circuit water supplementing tank 7 and the low-pressure safety injection assembly have the characteristic of combining active and passive, a high-pressure and medium-pressure safety injection system of a conventional reactor is cancelled, and the redundancy requirement and the safety injection capacity requirement are reduced.

Aiming at the working principle that the primary loop water replenishing tank 7 realizes passive core water replenishing: under normal operating conditions, the isolation valve 12 is in a closed state. In case of accident, when coolant in primary circuit is lost accidentally, such as the accident of rupture of the heat transfer pipe section 3 of the steam generator 2 and the accident of false opening of the safety valve of the pressure stabilizer 15, the isolating valve 12 of the front and rear pipelines of the water replenishing tank is opened under the automatic signal control or manual control of an operator, so that the water replenishing tank is communicated with the primary circuit. After the isolation valve 12 is opened, the pressure in the tank is equal to the pressure of a primary circuit, low-temperature boron-containing water in the primary circuit water supplementing tank 7 is injected into the reactor core by the gravity driving force generated by density difference, and hot water or steam in the section 3 of the heat pipe section fills the upper space of the water supplementing tank, so that the purpose of water supplementing of the reactor core is achieved.

Aiming at the activity of the low-pressure safety injection assembly, the working principle of core water supplement is realized: the low-temperature boron-containing water is filled in the safety injection water tank 10, the low-pressure safety injection pump 9 pumps water from the safety injection water tank 10, the water is pressurized and then injected into the section 4 of the cold pipe section of the primary loop, and the low-temperature boron-containing water in the safety injection water tank 10 is injected into the reactor core.

In the embodiment, an isolation valve 12 and a check valve 13 are connected in series between the low-pressure safety injection pump 9 and the cold pipe section 4 in sequence. The first connecting pipe 8 adopts a double-layer sleeve 5, and the section of the second connecting pipe 11 between the check valve 13 and the cold pipe section 4 also adopts the double-layer sleeve 5 as in a loop system.

Specifically, an isolation valve 12 and a check valve 13 are connected in series at the downstream of the safety injection pump, a double-layer pipeline is adopted from the downstream of the check valve 13 to the section 4 of the double-layer cold pipe section, and a single-layer pipeline is adopted from the upstream of the check valve 13 to the safety injection water tank 10. The existence of the check valve 13 can prevent the coolant in the downstream loop from reversely flowing out through the check valve 13 when the upstream pipeline is broken, thereby playing a role in isolating the broken opening. The purpose of doing so is to reduce the use of unnecessary double-deck pipeline, reduces the cost.

The reactor adopts a double-layer pipeline technology, a pipeline with a main large inner diameter (larger than 50 mm) in a primary loop containment is arranged as a double-layer sleeve 5, each layer of pipeline can independently bear the high temperature and the high pressure of a coolant, and meanwhile, a pressure sensor 6 is arranged in a double-layer pipeline gap 501 to monitor the pressure change in the gap 501 and judge whether the inner layer pipeline is broken or not in time. If the inner layer pipeline is broken, the outer layer pipeline can be used as a new pressure boundary to ensure the normal operation and radioactive containment of the reactor, and simultaneously, a high-pressure protection signal of the gap 501 is triggered to enable an operator to recognize the position where the broken opening occurs early, so that corresponding protection measures are taken to ensure the safety of the reactor, such as manual or automatic shutdown.

The double-layer pipeline can independently bear the operation pressure and temperature of a loop in design, the pressure of the gap 501 is very low even lower than the environmental pressure in normal operation, and meanwhile, the gap 501 of the double-layer pipeline is small, so that the possibility that the inner layer pipeline breaks and collides to cause the outer layer pipeline to break is eliminated, the double-layer pipeline cannot break simultaneously in design, and the occurrence of pipeline breakage accidents is avoided. In addition, the purpose of limiting the maximum breach of the primary loop to be not more than 50mm can be achieved by setting the primary loop pipeline with the inner diameter larger than 50mm (the inner diameter can be optimally adjusted according to the actual operating power and the water content of the reactor) to adopt a double-layer pipeline technology, the release of mass energy passing through the breach is limited, and a foundation is provided for simplifying a safety injection system and a containment pressure protection system.

The reactor only needs to be provided with a simple safety injection system by adopting a double-layer pipeline technology, and meanwhile, a containment pressure protection system can be simplified, so that the safety margin of the reactor is greatly improved, the manufacturing cost is reduced, and the economic performance is improved.

The above embodiments are only used to illustrate the technical solution of the present invention, and not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention in its corresponding aspects.

Claims (13)

1. A novel reactor based on double-layer pipeline technology comprises a loop system and a safety injection system, wherein the loop system at least comprises a pressure vessel and a steam generator for placing a reactor core, and the pressure vessel is communicated with the steam generator through a heat pipe section and a cold pipe section to form a coolant flow passage loop; the method is characterized in that: the heat pipe section and/or the cold pipe section are/is a double-layer sleeve, a gap is reserved between two layers of pipelines of the double-layer sleeve, and the double-layer sleeve is provided with a pressure sensor for monitoring pressure change in the gap.

2. The reactor of claim 1, further comprising a loop make-up water tank disposed above the pressure vessel, wherein the water inlet and the water outlet are respectively connected to the hot pipe section and the cold pipe section by a first connecting pipe.

3. The novel reactor based on double-layer pipeline technology as claimed in claim 2, characterized in that the first connecting pipe is a double-layer sleeve; and the primary loop water supplementing tank is filled with low-temperature boron-containing water.

4. The novel reactor based on double-layer pipeline technology as claimed in claim 2, characterized in that an isolation valve is arranged on the first connecting pipe; the first connecting pipe has an inner diameter greater than 50 mm.

5. The novel reactor based on the double-layer pipeline technology is characterized in that the safety injection system comprises a low-pressure safety injection assembly, the low-pressure safety injection assembly comprises a low-pressure safety injection pump and a safety injection water tank, the safety injection water tank is communicated with the cold pipe section through a second connecting pipe, and the low-pressure safety injection pump is installed on the second connecting pipe;

wherein, the safety injection water tank is filled with low-temperature boron-containing water, and the second connecting pipes are provided with isolating valves.

6. The novel reactor based on the double-layer pipeline technology as claimed in claim 5, wherein an isolation valve and a check valve are connected in series between the low-pressure safety injection pump and the cold pipe section in sequence.

7. The reactor of claim 6, wherein the second connecting pipe is a double-layer sleeve in the pipe section between the check valve and the cold pipe section.

8. The reactor of claim 6, wherein the second connecting pipe is further provided with a sub-port connected to a waste heat removal system for removing waste heat.

9. The novel reactor based on the double-layer pipeline technology as claimed in claim 1, wherein the reactor is further provided with a voltage stabilizer; the bottom of the pressure stabilizer is communicated with the heat pipe section through a fluctuation pipe, and the top of the pressure stabilizer is communicated with the cold pipe section through a spray pipe.

10. The reactor of claim 9, wherein the surge pipe and/or the shower pipe are double-walled sleeves.

11. The novel reactor based on the double-layer pipeline technology as claimed in any one of claims 1-10, wherein the double-layer sleeve is a pipeline with an inner diameter larger than 50mm and is positioned inside a containment vessel of the reactor.

12. The novel reactor based on double-layer pipeline technology as claimed in any one of claims 1-10, wherein the two pipelines of the double-layer casing are concentrically arranged, the gap distance between the two pipelines is 5mm, and the gap is filled with normal pressure dry air.

13. The reactor of claim 12, wherein a support is fixed between the two layers of the double-layer casing pipes.

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