A nuclear power icebreaker containment energy-absorbing buffer protection structure

Abstract

The application belongs to the field of ship design, and particularly relates to a nuclear power icebreaker safety shell energy-absorbing buffer protection structure applied to ice resistance of the nuclear power icebreaker. The structure comprises three regions, namely, an impact resistance region, a transition region and a reactor cabin. The impact resistance region is connected with the transition region, the transition region is connected with the reactor cabin, and the transition region is located between the impact resistance region and the reactor cabin. The application has the following beneficial effects: 1) the safety shell is better protected by setting an additional isolation cabin and its accessory structure outside the safety shell; 2) the stress distribution of the impact load transmission to the ship middle component is improved by setting a supporting longitudinal girder, so that the position of the high stress area is changed positively; and 3) the application has the characteristics that the stress is obviously weaker than that of the impact resistance region and the reactor cabin component, and a large number of openings are designed, so that when the ship is impacted by an extreme event, a clear buffer zone and a fracture interface are formed in the region, and the integrity of the reactor cabin safety shell is effectively protected.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of ship design, and particularly relates to a nuclear power icebreaker safety shell energy-absorbing buffer protection structure applied to the ice resistance of a nuclear power icebreaker. BACKGROUND

[0002] As a main carrier for exploring the polar region and an important ship type for opening up the northern route, the research on the polar icebreaker is of great significance to the national strategy and economic development, and the nuclear reactor is the optimal choice for the power source of the polar icebreaker.

[0003] The polar icebreaker must have the ice class of PC3 or above, that is, the ability to directly sail in water areas with ice layers of 1.5 meters or above in thickness; the high-performance icebreaker can maintain a speed of 3 knots or above in water areas with ice layers of 1.5 meters or above in thickness. Therefore, the ship outer plate and its connecting components (such as ribs, decks and supporting bulkheads) bear a large impact load.

[0004] Meanwhile, due to the space arrangement, damage stability and specification requirements of the nuclear power ship safety shell, the safety shell often occupies about 3 / 5 of the ship width, that is, the safety shell is only about 1 / 5 of the ship width away from the outer plate. Therefore, in addition to the requirements of shielding radiation, preventing leakage and bearing high temperature and high pressure, the outer wall of the safety shell is usually used as the ice-strengthened rib and the supporting bulkhead of the deck in the local area.

[0005] As can be seen from the above, the structure in the safety shell area is often relatively concentrated in stress, and unexpected structural damage may occur, leading to radiation leakage and the like.

[0006] Moreover, when the ship is subjected to a special side impact load (such as ship collision, iceberg, etc.), although it is not likely that the external object directly impacts the safety shell, the impact load will be quickly transmitted to the safety shell area, causing damage to the safety shell.

[0007] Therefore, how to keep the safety shell intact under the above conditions has been a key technology for the nuclear power icebreaker. SUMMARY

[0008] The purpose of the present application is to provide a nuclear power icebreaker safety shell energy-absorbing buffer protection structure, which can reduce the adverse effects of icebreaking impact load on the safety shell while ensuring that the relevant area components effectively transmit stress under normal working conditions, and can ensure the integrity of the safety shell to the greatest extent in the case of strong external impact on the ship.

[0009] The technical scheme of the present application is as follows: a nuclear power icebreaker safety shell energy-absorbing buffer protection structure, which comprises three regions, namely an impact resistance area, a transition area and a reactor cabin, the impact resistance area is connected to the transition area, the transition area is connected to the reactor cabin, and the transition area is located between the impact resistance area and the reactor cabin.

[0010] The impact-resistant zone comprises reinforced outer plates, side through-decks, intermediate deck strakes, reinforced ribs and supporting longitudinal girders, the reinforced outer plates are located at the outermost side, the reinforced outer plates are connected with a plurality of reinforced ribs at the inner side, the intermediate deck strakes are arranged between every two reinforced ribs, the outer side of the reinforced ribs is provided with the side through-decks, and the end of the reinforced ribs is connected with the supporting longitudinal girders.

[0011] The transition zone comprises a transition through-deck, an intermediate transition deck, a protective bulkhead and a wall lining deck, the transition through-deck is connected with the side through-deck in the impact-resistant zone, the intermediate transition deck is connected with the supporting longitudinal girders in the impact-resistant zone, the end of the intermediate transition deck is connected with the protective bulkhead, and the outer side of the protective bulkhead is provided with the wall lining deck.

[0012] The wall lining deck is provided with lightening holes.

[0013] The wall lining deck is connected with vertical supports of the bulkhead.

[0014] The intermediate transition deck is connected with transition materials.

[0015] The wall lining deck is provided with inner ribs and stiffeners.

[0016] The reactor compartment comprises a safety shell, and the safety shell is arranged at the outer side of the wall lining deck in the transition zone.

[0017] The safety shell and the transition zone form an isolation compartment.

[0018] The present application has the following beneficial effects: 1) the safety shell is better protected by arranging an additional isolation compartment and its accessory structures outside the safety shell; 2) the stress distribution of the impact load transmitted to the ship's middle member is improved by arranging the supporting longitudinal girders, so that the position of the high stress area is changed in a benign way; 3) the transition zone member has the characteristics of being obviously weaker than the impact-resistant zone and the reactor compartment member under the premise of meeting the member size of the conventional working condition design and the specification requirements, and a large number of openings are designed, so that a clear buffer zone and a fracture interface are formed in the region after the ship is impacted by an extreme event, thereby effectively protecting the integrity of the safety shell of the reactor compartment; 4) the present application provides a related regional structure design concept and a member design calculation scheme. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 It is a circular stack area distribution diagram;

[0020] Figure 2 It is a square stack area distribution diagram;

[0021] Figure 3 It is a strong frame section view;

[0022] Figure 4 Transitioned section for weak frame;

[0023] Figure 5 Non-transitioned section for weak frame;

[0024] Figure 6 Transitioned section for deck.

[0025] In the figure: 1 impact resistance area, 2 transition area, 3 reactor cabin, 11 reinforced outer plate, 12 side through deck, 13 intermediate deck side plate, 14 reinforced rib, 15 support longitudinal girder, 21 transition through deck, 22 intermediate transition deck, 23 protective bulkhead, 24 wall lining deck, 25 lightening hole, 26 bulkhead vertical support, 27 transition material, 28 wall inner rib plate, 29 stiffener, 31 containment, 32 isolation cabin. DETAILED DESCRIPTION

[0026] The application will be further described in conjunction with the accompanying drawings and specific embodiments.

[0027] As Figures 1-6 shown, a nuclear power icebreaker containment energy-absorbing buffer protection structure includes three areas, namely impact resistance area 1, transition area 2 and reactor cabin 3, impact resistance area 1 is connected to transition area 2, transition area 2 is connected to reactor cabin 3, and transition area 2 is located between impact resistance area 1 and reactor cabin 3.

[0028] The impact resistance area 1 includes reinforced outer plate 11, side through deck 12, intermediate deck side plate 13, reinforced rib 14 and support longitudinal girder 15, the reinforced outer plate 11 is located at the outermost side, the inside of the reinforced outer plate 11 is connected to a plurality of reinforced ribs 14, and every two reinforced ribs 14 are connected by an intermediate deck side plate 13, the outside of the reinforced rib 14 is connected to the side through deck 12, and the end of the reinforced rib 14 is connected to the support longitudinal girder 15.

[0029] The transition area 2 includes transition through deck 21, intermediate transition deck 22, protective bulkhead 23, wall lining deck 24, lightening hole 25, bulkhead vertical support 26, transition material 27, wall inner rib plate 28 and stiffener 29, the transition through deck 21 is connected to the side through deck 12 in the impact resistance area 1, the intermediate transition deck 22 is connected to the support longitudinal girder 15 in the impact resistance area 1, the end of the intermediate transition deck 22 is connected to the protective bulkhead 23, the outside of the protective bulkhead 23 is provided with the wall lining deck 24, the lightening hole 25 can be opened on the wall lining deck 24, the bulkhead vertical support 26 is connected to the wall lining deck 24, the transition material 27 is connected to the intermediate transition deck 22, and the wall inner rib plate 28 and the stiffener 29 are arranged on the wall lining deck 24.

[0030] The area involved by the reactor compartment 3 mainly refers to the containment 31 and the isolation compartment 32 formed between the containment 31 and the transition zone 2.

[0031] In the normal working condition:

[0032] The impact-resistant zone 1 mainly considers the influence of external ice load, and generally ensures the internal arrangement of the reactor compartment, so the width of the reactor compartment is made as large as possible (i.e., the distance between the containment and the outer plate is minimized). According to the nuclear energy commercial ship specification, the distance between the outer plate and the containment is not less than 1 / 5 of the ship width, so the stiffening rib 14 in the conventional design is often directly connected to the nearest bulkhead structure, and the impact load is finally transmitted to the corresponding bulkhead. At the same time, the containment needs to withstand the pressure in the internal extreme accident condition, and the pressure will also be transmitted outward from the containment. When the stress in two directions is concentrated on the components near the containment, deformation, stress failure or fatigue failure of the corresponding components may occur, resulting in damage to the integrity of the containment.

[0033] To prevent this situation, the application additionally designs a protective bulkhead 23 outside the containment, which forms an isolation compartment 32 with the containment 31. A support girder 15 is designed between the protective bulkhead and the outer plate, and the component size of the support girder should be not less than the deck lower part of the stiffening rib 14. Most of the external ice load is stopped near the support girder 15, and the outward transmission of the internal pressure of the reactor compartment is blocked by the containment 31 and the protective bulkhead 23.

[0034] At the same time, in order to ensure the reliability of the support girder 15, a transition material 27 is arranged between the support girder 15 and the protective bulkhead 23. If the spacing of the stiffening rib 14 is s, the spacing of the transition material 27 should be 2n*s, and n is a positive integer. The specific value is determined according to different designs. In order to ensure the buffering effect, the component size of the transition material 27 should be not greater than the deck lower part of the stiffening rib 14.

[0035] In the external impact accident condition

[0036] The structure of the impact-resistant zone 1 is damaged, and since the distance between the containment and the outer plate is greater than 1 / 5 of the ship width, the impact-resistant zone 1 is generally not directly impacted. However, it may be subjected to instantaneous impact load transmitted by other components. Therefore, the deck edge plate 13 is designed to be appropriately strengthened, and the thickness value should be increased by more than 20% compared with the thickness value required in the normal working condition calculation; the thickness of the intermediate transition deck 22 is 1 / 2 of the thickness of the intermediate deck edge plate 13, but it should not be less than the minimum thickness required by the ship industry specification and the normal working condition calculation. In this way, the intermediate transition deck 22 can be directly damaged and deformed under the action of the instantaneous impact load, so as to avoid the continuous transmission of the impact load.

[0037] When the intermediate transition deck is destroyed, if the external object continues to impact inward to the protective bulkhead 23, to avoid the adverse effects of the protective bulkhead destruction on the containment vessel, the present application designs a weaker support in the isolation cabin 32 to produce structural damage first, such as the wall lining deck 24 and the wall inner rib plate 28 are provided with dense lightening holes 25, so that the cross section of the deck and rib plate is small, and the impact energy is absorbed. Thus, the safety and integrity of the containment vessel 31 are maximized.

[0038] In the design embodiment, the present application considers that the load transmitted by the top deck to the ship center has less effect on the containment vessel, and the through deck 12 and the transition through deck 21 connected with the top of the containment vessel or near the position and the attached support longitudinal beam 15 should not be designed according to the above requirements.

[0039] The present application provides two types of transition area division scheme embodiments as shown in the drawings. Figure 1 , Figure 2 The transition area of the circular stack cabin is relatively small, and analysis shows that the length of the transition area 2 of the square stack cabin should be greater than the total length of the containment vessel 31; the length of the transition area 2 of the circular stack cabin or the elliptical stack cabin should be not less than the radius of the maximum circular arc of the containment vessel 31; and the length of the transition area 2 of the waist round type stack cabin should be the sum of the circular arc radius and the straight section length.

[0040] The above is only a preferred embodiment of the present application, and is not intended to limit the scope of the present application. Any equivalent changes and modifications made in accordance with the shape, structure, features and spirit of the present application are included in the scope of the claims of the present application.

Claims

1. An energy-absorbing and buffering protective structure for the containment hull of a nuclear-powered icebreaker, characterized in that: It includes three areas: the shock-resistant zone, the transition zone, and the reactor compartment. The shock-resistant zone is connected to the transition zone, the transition zone is connected to the reactor compartment, and the transition zone is located between the shock-resistant zone and the reactor compartment. The impact-resistant zone includes a reinforced outer plate, a side through deck, an intermediate deck side plate, reinforcing ribs, and supporting longitudinal girder. The reinforced outer plate is located on the outermost side, and multiple reinforcing ribs are connected to the inner side of the reinforced outer plate. The intermediate deck side plate is between every two reinforcing ribs, and the side through deck is outside the outer reinforcing ribs. The ends of the reinforcing ribs are connected to the supporting longitudinal girder. The dimensions of the supporting longitudinal girder are not smaller than the lower deck portion of the reinforcing rib, so that most of the external ice load remains near the supporting longitudinal girder. The transition zone includes a transition through deck, an intermediate transition deck, a protective bulkhead, and a liner deck. The transition through deck is connected to the side through deck in the impact resistance zone, the intermediate transition deck is connected to the supporting longitudinal girder in the impact resistance zone, the end of the intermediate transition deck is connected to the protective bulkhead, and a liner deck is provided on the outside of the protective bulkhead. Lightening holes are made in the aforementioned wall lining deck; The bulkhead deck is connected to vertical bulkhead supports; The size of the transition skeleton is no larger than the lower part of the reinforced rib deck; a transition skeleton is provided between the supporting longitudinal girder and the protective bulkhead; a transition skeleton is connected to the intermediate transition deck; The wall lining deck is provided with inner wall ribs and stiffeners.

2. The energy-absorbing and buffering protection structure for the containment hull of a nuclear-powered icebreaker as described in claim 1, characterized in that: The reactor compartment includes a containment vessel, which is located outside the wall lining deck of the transition zone.

3. The energy-absorbing and buffering protection structure for the containment hull of a nuclear-powered icebreaker as described in claim 2, characterized in that: An isolation compartment is formed between the containment vessel and the transition zone.

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