Coolant system of high-temperature gas cooled reactor

Abstract

The invention discloses a high-temperature gas cooled reactor coolant system, and relates to the technical field of overall design of nuclear power plants. Comprising a reactor pressure vessel, a heat exchange part arranged on the reactor pressure vessel, and a main helium fan arranged on the heat exchange part; the cooling unit comprises a cooling part connected to the heat exchange part and a water storage bin arranged below the cooling part. Heat exchange between reactor coolant helium and feed water is achieved through heat pipe heat exchange, the helium firstly transfers heat to the heat absorption end of the heat pipe, after the heat absorption end of the heat pipe absorbs heat, the heat is transferred to the heat release end, and the heat is transferred to the feed water at the heat release end. The heat pipe is vertically arranged, the length is short, the thermal stress is small, the two ends of the heat pipe are not limited to stretch out and draw back freely, and therefore the problem that the thermal stress is too large does not exist. The heat pipe is short, the cross section is large, detection equipment meets the reachability requirement, in-service inspection is easy to achieve, the heat pipe technology is adopted, heat generated in the reactor operation process is released to feed water through the heat pipe heat exchanger, and compared with an existing technical scheme, the technical scheme is simple in structure, reliable in operation, low in cost and easy to maintain.

Description

Technical Field

[0001] The invention relates to the technical field of overall design of nuclear power plants, and in particular to a high temperature gas-cooled reactor coolant system. Background Art

[0002] At present, the coolant system of high temperature gas-cooled reactor is composed of reactor pressure vessel, hot gas duct, main helium blower, steam generator and other main equipment. At present, there are the following technical and economic problems:

[0003] 1) The steam generator is a small spiral coil heat exchanger with a complex internal structure, making it difficult to solve the problems of heat transfer tube stress and in-service inspection.

[0004] 2) The helium on the primary side of the steam generator and the feed water on the secondary side are isolated by the wall of the heat exchange tube. In the event of a rupture of the heat exchange tube, the water on the secondary side enters the primary side and then enters the reactor core, corroding the fuel elements and posing a hazard to safe operation.

[0005] 3) The flow distribution on the primary and secondary sides of the steam generator is uneven, resulting in a large temperature difference at the steam outlet and excessive thermal stress in the nozzle.

[0006] 4) The primary side of the steam generator is nuclear safety level 1, and the secondary side is nuclear safety level 2. The equipment requirements are high, which increases the equipment cost.

[0007] 5) The water quality on the secondary side of the steam generator cannot be controlled and sewage cannot be discharged. The ions on the secondary side continue to accumulate, the concentration becomes higher and higher, and the heat transfer tubes are continuously corroded, causing hidden dangers.

[0008] In order to solve the above problems, the present invention patent designs a simple reactor coolant system. Summary of the invention

[0009] In view of the above-mentioned problems existing in the existing high temperature gas-cooled reactor coolant system, the present invention is proposed.

[0010] Therefore, the purpose of the present invention is to provide a high-temperature gas-cooled reactor coolant system, which aims to: solve the technical problems in the prior art that the thermal stress of the steam generator heat transfer tube is not easy to balance with the in-service inspection; when the steam generator heat transfer tube is broken, the secondary side feed water / steam enters the core, causing a safety accident; the uneven flow distribution of the steam generator leads to a large temperature difference at the steam outlet and a large thermal stress at the nozzle; the equipment has a high safety level and a high cost; the secondary side of the steam generator cannot be continuously discharged, which easily corrodes the heat transfer tube.

[0011] In order to solve the above technical problems, the present invention provides the following technical solutions: comprising:

[0012] A heat exchange unit, comprising a reactor pressure vessel, a heat exchange portion disposed on the reactor pressure vessel, and a main helium blower disposed on the heat exchange portion;

[0013] The cooling unit comprises a cooling part connected to the heat exchange part and a water storage tank arranged below the cooling part.

[0014] As a preferred solution of the high temperature gas-cooled reactor coolant system of the present invention, the heat exchange part includes a heat pipe assembly arranged on the reactor pressure vessel, and a heat transfer assembly arranged on the side of the heat pipe assembly away from the reactor pressure vessel.

[0015] As a preferred solution of the high temperature gas-cooled reactor coolant system of the present invention, the heat pipe assembly includes a hot gas duct inner tube arranged on the reactor pressure vessel, a helium inner header box connected to the hot gas duct inner tube, a hot gas duct outer tube surrounding the outside of the hot gas duct inner tube, and a helium outer header box connected to the hot gas duct outer tube.

[0016] As a preferred solution of the high temperature gas-cooled reactor coolant system of the present invention, a partition is provided between the helium inner header box and the helium outer header box.

[0017] As a preferred solution of the high temperature gas-cooled reactor coolant system of the present invention, a helium air inlet pipeline is provided on the helium outer junction box.

[0018] As a preferred solution of the high-temperature gas-cooled reactor coolant system of the present invention, the heat transfer component includes a thermal pipe arranged on the helium inner header, a water vapor header connected to the thermal pipe, a steam nozzle arranged at the top of the water vapor header, and a water supply nozzle arranged at the lower end of the water vapor header.

[0019] As a preferred solution of the high temperature gas-cooled reactor coolant system of the present invention, a heat pipe nozzle is arranged at the top of the thermal pipe, and heat exchange fins are arranged on the outer surface of the thermal pipe.

[0020] As a preferred solution of the high temperature gas-cooled reactor coolant system of the present invention, a sewage discharge nozzle is also provided at the bottom of the water vapor header.

[0021] As a preferred solution of the high temperature gas-cooled reactor coolant system of the present invention, the cooling part includes a stainless steel inner tube arranged in the thermal tube, a heat release channel arranged on the stainless steel inner tube, and a skirt arranged at the bottom of the stainless steel inner tube.

[0022] As a preferred solution of the high temperature gas-cooled reactor coolant system of the present invention, the cooling part is composed of a heat release section, a heat insulation section and a heat absorption section from top to bottom.

[0023] The beneficial effects of the present invention are as follows: a) The heat exchange between the reactor coolant helium and the feed water is realized by heat exchange with the heat pipe. The helium first transfers the heat to the heat absorbing end of the heat pipe. After the heat absorbing end of the heat pipe absorbs the heat, the heat is transferred to the heat releasing end, and the heat is transferred to the feed water at the heat releasing end. The heat pipe is arranged vertically, the length is short, the thermal stress is small, and the two ends of the heat pipe are free to expand and contract without restriction, so there is no problem of excessive thermal stress. The heat pipe is short and the cross-section is large. The detection equipment meets the accessibility requirements, and it is easy to realize in-service inspection.

[0024] b) The primary side (helium side) and the secondary side (water supply / steam side) are isolated by heat pipes. Even if the heat pipe breaks, the secondary side water supply / steam will not enter the primary side, fundamentally avoiding safety accidents caused by heat transfer pipe rupture.

[0025] c) No ports are required on the primary side (helium side) and secondary side of the heat pipe heat exchanger for flow distribution, thus solving the problem of large temperature difference at the steam outlet.

[0026] d) The primary side (helium side) and the heat pipe absorption section of the heat pipe exchanger are nuclear safety level 1, while the secondary side (feed water / steam side) and the heat pipe insulation section and heat release section are non-safety level, which reduces the safety level of the equipment, thereby reducing requirements, reducing costs and improving economy.

[0027] e) It can realize continuous sewage discharge to avoid the accumulation of pollutants and corrosion of heat transfer tubes.

[0028] The present invention adopts heat pipe technology to release the heat generated during the operation of the reactor to the feed water through a heat pipe heat exchanger. Compared with the existing technical solutions, the technical solution of the present invention has a simple structure, reliable operation, low cost and easy maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:

[0030] Figure 1 It is a schematic diagram of the overall structure of the coolant system of the high temperature gas-cooled reactor of the present invention.

[0031] Figure 2 It is a schematic diagram of the structure of the cooling unit of the coolant system of the high temperature gas-cooled reactor of the present invention. DETAILED DESCRIPTION

[0032] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0033] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0034] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor is it a separate or selective embodiment that is mutually exclusive with other embodiments.

[0035] Secondly, the present invention is described in detail with reference to the schematic diagram. When describing the embodiments of the present invention in detail, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0036] Example 1

[0037] Reference Figure 1-2 , which is the first embodiment of the present invention, provides a high temperature gas-cooled reactor coolant system, the device comprising:

[0038] The heat exchange unit 100 includes a reactor pressure vessel 101, a heat exchange part 102 arranged on the reactor pressure vessel 101, and a main helium blower 103 arranged on the heat exchange part 102. A ballpark-type reactor is installed inside the reactor pressure vessel 101, and the reactor is cooled by helium. The helium absorbs the heat of the reactor and is cooled by the heat exchange part 102. Then, the pressure head is increased by the main helium blower 103 and the helium returns to the reactor pressure vessel 101 again, thereby realizing heat transfer and circulation.

[0039] The cooling unit 200 includes a cooling part 201 connected to the heat exchange part 102, and a water storage tank 202 arranged below the cooling part 201, which further cools the heat brought out from the heat exchange part 102, and generates steam through a medium in the water storage tank 202, such as salt water, sodium or mercury, to drive a turbine to generate electricity, and the cooled water returns to the water storage tank 202 for recycling.

[0040] The heat exchange part 102 includes a heat pipe assembly 102a disposed on the reactor pressure vessel 101, and a heat transfer assembly 102b disposed on the side of the heat pipe assembly 102a away from the reactor pressure vessel 101. The heat pipe assembly 102a uses the circulation of helium to transfer heat to achieve rapid heat transfer. The heat transfer assembly 102b transfers the heat brought out of the helium from the heat pipe assembly 102a to the medium in the water storage tank 202, so that the water is heated and steam is generated. This process is a key step in energy conversion, which converts nuclear energy into thermal energy, then converts thermal energy into mechanical energy, and finally into electrical energy. .

[0041] During use, the staff starts the main helium fan 103 and checks all connections and seals to ensure there are no leaks. The reactor is then gradually heated. The helium absorbs heat in the reactor pressure vessel 101 and is then transferred to the heat transfer assembly 102b through the heat pipe assembly 102a. The thermal pipe 102b-1 in the heat transfer assembly 102b transfers the heat to the medium in the water storage tank 202, heating the water and generating steam to drive the turbine generator and convert it into electrical energy. The cooled helium returns to the reactor pressure vessel 101 to continue absorbing heat.

[0042] Example 2

[0043] Reference Figure 1-2 , which is a second embodiment of the present invention. This embodiment is different from the first embodiment in that: a heat pipe assembly 102a includes a hot gas pipe inner pipe 102a-1 arranged on a reactor pressure vessel 101, a helium inner header box 102a-2 connected to the hot gas pipe inner pipe 102a-1, a hot gas pipe outer pipe 102a-3 surrounding the outside of the hot gas pipe inner pipe 102a-1, and a helium outer header box 102a-4 connected to the hot gas pipe outer pipe 102a-3. The hot gas pipe inner pipe 102a-1 transports hot helium, so that the hot helium flows from the reactor pressure vessel 101 into the helium inner header box 102a-2. The outside of the hot gas pipe inner pipe 102a-1 is wrapped by the hot gas pipe outer pipe 102a-3, so that the hot gas pipe inner pipe 102a-1 does not need to bear the internal and external pressure difference, thereby reducing the manufacturing difficulty of the hot gas pipe inner pipe 102a-1 and reducing the cost. The inner tube 102a-1 of the hot gas duct extends into the interior of the helium inner header box 102a-2, and the hot helium enters the helium inner header box 102a-2, so that the helium flow rate flows evenly in the helium inner header box 102a-2. The outer tube 102a-3 of the hot gas duct is used to transport the refluxed cold helium, so that the cold helium flows into the reactor pressure vessel 101 from the helium outer header box 102a-4, and the helium outer header box 102a-4 provides a pressure boundary for the cold helium.

[0044] Compared with Example 1, further, a partition 102a-5 is provided between the helium inner header box 102a-2 and the helium outer header box 102a-4 to isolate the inlet and outlet of the main helium blower 103 and prevent the gas above the partition 102a-5 and the gas below from communicating with each other. The partition 102a-5 is located between the helium inner header box 102a-2 and the helium outer header box 102a-4.

[0045] Compared with Example 1, further, a helium wind inlet pipe 102a-6 is provided on the helium outer junction box 102a-4, and the cold helium gas that is cooled and pressurized by the main helium blower 103 flows back to the reactor pressure vessel 101 along the hot gas duct outer pipe 102a-3.

[0046] Compared with Example 1, the heat transfer component 102b further includes a heat pipe 102b-1 disposed on the helium inner header 102a-2, a water vapor header 102b-2 connected to the heat pipe 102b-1, a steam pipe nozzle 102b-3 disposed at the top of the water vapor header 102b-2, and a water supply pipe nozzle 102b-4 disposed at the lower end of the water vapor header 102b-2. The hot helium enters the helium inner header 102a-2 through the hot gas conduit inner pipe 102a-1, flows through a plurality of heat pipes 102b-1, and transfers heat to the medium in the water storage tank 202 through the heat pipe fins. After the medium is heated, it becomes steam and transfers heat to the feed water / steam in the water-steam header 102b-2 through the fins. After cooling down, it condenses into water. The hot helium is cooled by a number of thermal pipes 102b-1 and becomes cold helium. It flows upward along the gap between the helium inner header 102a-2 and the helium outer header 102a-4, reaches the partition 102a-5, enters the main helium blower 103 through the helium wind inlet pipe 102a-6, is pressurized and discharged to the upper space of the partition 102a-5, and then returns to the reactor pressure vessel 101 through the hot gas duct outer pipe 102a-3.

[0047] Compared with Example 1, further, a heat pipe nozzle 102b-5 is provided at the top of the heat pipe 102b-1, and a heat exchange fin 102b-6 is provided on the outer surface of the heat pipe 102b-1. The heat pipe nozzle 102b-5 can control and guide the flow direction of steam or hot water generated in the heat pipe 102b-1. It can be designed into different shapes and sizes to adapt to different connection requirements and flow control. By designing the heat pipe nozzle 102b-5, the flow characteristics of the fluid can be optimized, the pressure loss can be reduced, and the heat exchange efficiency can be improved; the heat exchange fin 102b-6 increases the surface area of ​​the heat pipe 102b-1, which can improve the heat exchange efficiency between the heat pipe 102b-1 and the surrounding fluid (such as water or steam), thereby improving the thermal efficiency of the entire system. When in use, the number, shape and spacing of the fins can be adjusted to adapt to different heat loads and fluid dynamics conditions. In addition, the fins can also improve the corrosion resistance and wear resistance of the system and extend the service life of the equipment.

[0048] Compared with Example 1, a sewage discharge nozzle 102b-7 is further provided at the bottom of the water-steam manifold 102b-2. After the feed water evaporates continuously, the impurity ions accumulate continuously and the concentration becomes higher and higher. The sewage is discharged through the sewage discharge nozzle 102b-7 to alleviate the corrosion of the thermal pipe 102b-1 and the wall of the steam-water manifold caused by the accumulation of impurity ion concentration.

[0049] The remaining structures are the same as those of Example 1.

[0050] Example 3

[0051] Reference Figure 1-2 , which is the third embodiment of the present invention. This embodiment is different from the second embodiment in that: the cooling part 201 includes a stainless steel inner tube 201a arranged in the thermal pipe 102b-1, a heat release channel 201b arranged on the stainless steel inner tube 201a, and a skirt 201c arranged at the bottom of the stainless steel inner tube 201a. The main function of the stainless steel inner tube 201a is to provide a water flow channel so that the medium can flow inside the thermal pipe 102b-1, thereby absorbing heat and cooling. The heat release channel 201b allows the medium to contact the outer wall of the thermal pipe 102b-1 during the flow process, thereby absorbing heat more effectively, and the skirt 201c helps the distribution and flow of the medium to ensure that the heat exchange efficiency between the medium and the thermal pipe 102b-1 is maximized, thereby improving the cooling effect.

[0052] Compared with Example 2, further, the cooling part 201 is respectively composed of a heat release section m, a heat insulation section n and a heat absorption section k from top to bottom. The heat release section m of the thermal pipe 102b-1 is located in the water vapor header 102b-2, and the heat absorption section k is located in the helium inner header 102a-2; the heat insulation section n is located between the helium inner header 102a-2 and the water vapor header 102b-2, and an insulation layer is installed outside the heat insulation section n for heat insulation treatment so that it does not exchange heat with the outside world. The pressure-bearing boundary of the helium outer header 102a-4 belongs to the first level of nuclear safety, and the part of the thermal pipe 102b-1 located in the helium outer header 102a-4 belongs to the first level of nuclear safety equipment, while the steam-water header and other parts of the thermal pipe 102b-1 belong to the non-safety level, the helium outer header 102a-4 is not in direct contact with the steam-water header, and the steam-water header has no direct contact with the steam-water header. Water / steam will not enter the helium outer header 102a-4 or the helium inner header 102a-2, which fundamentally avoids the situation where water / steam enters the reactor pressure vessel 101; even if the heat absorption section k of the thermal pipe 102b-1 located in the helium inner header 102a-2 is ruptured, only the medium in the water storage tank 202 may enter the reactor in the reactor pressure vessel 101, and the amount of medium in a thermal pipe 102b-1 is very small, which will not affect nuclear safety; and the pressure of the thermal pipe 102b-1 may be lower than the helium pressure in the helium inner header 102a-2, and the possibility of the medium entering the reactor pressure vessel 101 is even smaller; for the situation where the heat absorption section k and the heat release section m of the same thermal pipe 102b-1 are ruptured at the same time, due to the very low probability, it is not considered as a design basis accident.

[0053] The remaining structure is the same as that of Example 2.

[0054] Importantly, it should be noted that the construction and arrangement of the present application shown in a plurality of different exemplary embodiments are only exemplary. Although only a few embodiments are described in detail in this disclosure, it should be readily understood by those who refer to this disclosure that many modifications are possible (e.g., the size, scale, structure, shape and proportion of various elements, as well as parameter values ​​(e.g., temperature, pressure, etc.), mounting arrangements, use of materials, color, directional changes, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in the application. For example, the element shown as integrally formed can be composed of multiple parts or elements, the position of the element can be inverted or otherwise changed, and the nature or number or position of the discrete element can be changed or changed. Therefore, all such modifications are intended to be included in the scope of the present invention. The order or sequence of any process or method steps can be changed or reordered according to alternative embodiments. In the claims, any "device plus function" clause is intended to cover the structure described herein that performs the function, and is not only structurally equivalent but also equivalent structure. Without departing from the scope of the present invention, other replacements, improvements, changes and omissions can be made in the design, operating conditions and arrangement of the exemplary embodiments. Therefore, the invention is not limited to a specific embodiment, but extends to numerous modifications still falling within the scope of the appended claims.

[0055] Additionally, in order to provide a concise description of exemplary embodiments, all features of an actual embodiment may not be described (ie, those features that are not relevant to the best mode presently contemplated for carrying out the invention or those that are not relevant to implementing the invention).

[0056] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A high temperature gas-cooled reactor coolant system, characterized in that: include, A heat exchange unit (100) comprises a reactor pressure vessel (101), a heat exchange portion (102) arranged on the reactor pressure vessel (101), and a main helium blower (103) arranged on the heat exchange portion (102); The cooling unit (200) comprises a cooling part (201) connected to the heat exchange part (102), and a water storage tank (202) arranged below the cooling part (201).

2. The high temperature gas-cooled reactor coolant system according to claim 1, characterized in that: The heat exchange part (102) comprises a heat pipe assembly (102a) arranged on the reactor pressure vessel (101), and a heat transfer assembly (102b) arranged on a side of the heat pipe assembly (102a) away from the reactor pressure vessel (101).

3. The high temperature gas-cooled reactor coolant system according to claim 2, characterized in that: The heat pipe assembly (102a) comprises a hot gas conduit inner tube (102a-1) arranged on the reactor pressure vessel (101), a helium inner header box (102a-2) connected to the hot gas conduit inner tube (102a-1), a hot gas conduit outer tube (102a-3) surrounding the outside of the hot gas conduit inner tube (102a-1), and a helium outer header box (102a-4) connected to the hot gas conduit outer tube (102a-3).

4. The high temperature gas-cooled reactor coolant system according to claim 3, characterized in that: A partition (102a-5) is provided between the helium inner header box (102a-2) and the helium outer header box (102a-4).

5. The high temperature gas-cooled reactor coolant system according to claim 4, characterized in that: The helium outer connection box (102a-4) is provided with a helium wind inlet pipe (102a-6).

6. The high temperature gas-cooled reactor coolant system according to claim 5, characterized in that: The heat transfer component (102b) comprises a thermal pipe (102b-1) arranged on the helium inner header (102a-2), a water vapor header (102b-2) connected to the thermal pipe (102b-1), a steam nozzle (102b-3) arranged at the top of the water vapor header (102b-2), and a water supply nozzle (102b-4) arranged at the bottom of the water vapor header (102b-2).

7. The high temperature gas-cooled reactor coolant system according to claim 6, characterized in that: A heat pipe nozzle (102b-5) is arranged at the top end of the heat pipe (102b-1), and a heat exchange fin (102b-6) is arranged on the outer surface of the heat pipe (102b-1).

8. The high temperature gas-cooled reactor coolant system according to claim 7, characterized in that: A sewage discharge nozzle (102b-7) is also provided at the bottom of the water vapor header (102b-2).

9. The high temperature gas-cooled reactor coolant system according to claim 8, characterized in that: The cooling part (201) comprises a stainless steel inner tube (201a) arranged in the thermal pipe (102b-1), a heat release channel (201b) arranged on the stainless steel inner tube (201a), and a skirt (201c) arranged at the bottom of the stainless steel inner tube (201a).

10. The high temperature gas-cooled reactor coolant system according to claim 9, characterized in that: The cooling section (201) consists of a heat release section (m), a heat insulation section (n) and a heat absorption section (k) from top to bottom.

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