CN117790028A - Radiating device and radioactive article transportation system - Google Patents

Abstract

The invention discloses a heat dissipation device and a radioactive article transportation system, wherein the heat dissipation device comprises: a plurality of heat sinks. The plurality of radiating fins encircle the circumference of the cylinder body to be radiated and are connected with the outer side wall of the cylinder body for radiating the cylinder body. The length direction of fin sets up along the central axis direction of barrel, and the radial setting of barrel is followed to width direction, and the fin is equipped with bifurcation structure in the one side of keeping away from the barrel, and bifurcation structure includes two or more bifurcation fins. A first flow channel is formed between two adjacent cooling fins, a second flow channel is formed between the branch fins, the cooling fins are used for natural convection cooling, and gas flows from the lower end to the upper end of the flow channel, so that heat of the cylinder body is taken away. The heat radiator does not need to be provided with forced convection equipment, is suitable for being applied to a radioactive article transportation system, can effectively increase the heat exchange area, and further improves the heat exchange efficiency of heat convection.

Description

Radiating device and radioactive article transportation system

Technical Field

The invention particularly relates to a heat dissipation device and a radioactive article transportation system.

Background

In a nuclear power plant, a device containing radioactive contents is loaded and transported by a transport container, and because the radioactive contents contain a relatively high heat source, a plurality of cooling fins (also called ribs and cooling fins) are required to be arranged on the outer surface of a cylinder body of the transport container, and the cooling fins are used for taking away heat emitted by the radioactive contents.

The general transportation container adopts the straight-flow type fins as the radiating fins, and the radiating principle of the radiating fins is to take away the heat generated by the content in the container in the forms of heat conduction, heat convection and heat radiation. Among them, a form of heat transfer by natural convection of air in the rib (i.e., a form of heat convection) plays a major role. The direct-flow type rib has simple structure, but has weak heat convection and heat dissipation capability, and has limited heat exchange capability on the container, so that the heat dissipation requirement of radioactive contents cannot be met.

Disclosure of Invention

The invention aims to solve the technical problems in the prior art and provides a heat radiating device and a radioactive article transportation system, wherein the heat radiating device can effectively increase the heat exchanging area so as to improve the heat exchanging efficiency of heat convection.

According to an embodiment of the first aspect of the present invention, there is provided a heat dissipating device including: a plurality of heat sinks. The cooling fins encircle the circumference of the cylinder body to be cooled and are connected with the outer side wall of the cylinder body to cool the cylinder body. The length direction of fin is followed the central axis direction of barrel sets up, and the width direction is followed the radial setting of barrel, the fin is keeping away from one side of barrel is equipped with bifurcation structure, bifurcation structure includes two or more bifurcation fins. A first flow channel is formed between two adjacent cooling fins, a second flow channel is formed between the bifurcation fins, the cooling fins are used for carrying out natural convection cooling, and gas flows to the upper end from the lower end of the flow channel, so that heat of the cylinder body is taken away.

Preferably, the heat sink further comprises a main fin, wherein the main fin is located between the bifurcation fin and the cylinder, one end of the main fin is connected with the side wall of the cylinder, and the other end of the main fin is connected with the bifurcation fin.

Preferably, the number of the bifurcated fins is two, and the cross section of the radiating fin is Y-shaped.

Preferably, the thickness of the bifurcated fin is gradually reduced in a direction away from the main fin.

Preferably, a plurality of radiating fins are arranged in an annular shape, the included angle range between every two adjacent radiating fins is 5-12 degrees, and the thickness range of the main fin in each radiating fin is 10-20 mm.

Preferably, the fin material is made of stainless steel material.

According to an embodiment of the second aspect of the present invention, there is provided a radioactive article transport system including a housing, a cylinder, and the heat dissipating device described above. The shell comprises a heat-preserving side wall, a fireproof cover and a base, wherein the fireproof cover and the base are respectively connected with the upper end and the lower end of the heat-preserving side wall, a first convection opening is formed in the fireproof cover, and a second convection opening is correspondingly formed in the base. The barrel is located inside the shell and is mounted on the base, the barrel is of a sealing structure and used for placing radioactive objects, a heat dissipation cavity is arranged between the outer wall of the barrel and the heat preservation side wall, the heat dissipation cavity is annular and surrounds the barrel, the upper end and the lower end of the heat dissipation cavity are respectively communicated with the first convection opening and the second convection opening, and air flows into the heat dissipation cavity through the second convection opening and flows out of the heat dissipation cavity through the first convection opening. The heat dissipation device is positioned in the heat dissipation cavity, and the heat dissipation fins of the heat dissipation device are connected with the outer side wall of the cylinder body and used for naturally carrying out convection heat dissipation on the cylinder body.

Preferably, the cylinder body comprises an outer cylinder and an inner cylinder, the radiating fins of the radiating device are connected with the outer side wall of the outer cylinder, the inner cylinder is accommodated in the outer cylinder and is placed along the same vertical central axis with the outer cylinder, the upper end of the inner cylinder is connected with the upper end of the outer cylinder, and the inner cylinder is used for placing radioactive objects; the inner cylinder is internally provided with isolation water which is used for shielding the radiation of the radioactive article once.

Preferably, a lead filling layer is arranged between the outer cylinder and the inner cylinder and is used for secondarily shielding the radiation of the radioactive article; the cylinder body further comprises a shielding plug, wherein the shielding plug is arranged at the opening of the upper end of the inner cylinder and is used for sealing the opening of the upper end of the inner cylinder.

Preferably, a gap exists between the vertical outer edge of the radiating fin and the heat-preserving side wall of the shell so as to leave an airflow channel.

Compared with the existing straight plate type fins, the heat exchange area of the heat radiating fin of the heat radiating device can be effectively increased, and the heat exchange efficiency is improved. Specifically, the high heat of the radioactive material in the cylinder is transferred to the heat sink by heat conduction, and the air fluid around the cylinder and the heat sink is heated to reduce its density, which creates buoyancy relative to the surrounding cooler fluid. Thus, the hot fluid will rise and the cold fluid will sink, forming a convective loop. The convective motion of such fluids is known as natural convection. Natural convection heat transfer can take away the heat of the cylinder and its radioactive contents without the need for tools such as fans to force air convection. The thickness of the bifurcation fins of the radiating fin is thinner, so that the heat exchange area, namely the contact area between air fluid and the fins, can be greatly increased under the condition that the flow resistance is not improved and the thermal resistance is not improved, and the heat exchange efficiency of heat convection can be further improved.

The heat dissipation device is arranged in a heat dissipation cavity of the radioactive article conveying system, the upper end and the lower end of the heat dissipation cavity are respectively connected with a first convection opening and a second convection opening, air fluid enters the heat dissipation cavity from the second convection opening at the lower end and flows through the heat dissipation fin upwards, and flows out through the first convection opening at the upper end to take away heat in the heat dissipation cavity.

In conclusion, the heat radiating device does not need to be provided with forced convection equipment, is suitable for being applied to a radioactive article transportation system, can effectively increase the heat exchange area, and further improves the heat exchange efficiency of heat convection.

Drawings

FIG. 1 is a schematic diagram of a radioactive material transport system in some embodiments of the present invention;

FIG. 2 is a schematic view of the structure of a cartridge in some embodiments of the invention;

FIG. 3 is a schematic diagram of a heat sink layout in some embodiments of the invention;

fig. 4 is a schematic diagram of a heat sink in some embodiments of the invention.

In the figure: 1-shell, 2-barrel, 3-outer barrel, 4-inner barrel, 5-shielding plug, 6-fireproof cover, 7-hanging basket, 8-fireproof sleeve, 9-upper forging, 10-upper angle plate, 11-upper butt strap, 12-fireproof filler, 13-lifting lug, 14-lead filling layer, 15-heat radiating device, 151-radiating fin, 152-main fin, 153-forked fin, 16-drain pipe, 17-cover plate groove, 18-drain hole cover, 19-bottom base plate, 20-outer barrel bottom plate, 21-bottom filler and 22-base.

Detailed Description

The following description of the embodiments of the present invention will be made more apparent, and the embodiments described in detail, but not necessarily all, in connection with the accompanying drawings. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to fall within the scope of the invention.

In the description of the present invention, it should be noted that, the terms "upper," "lower," and the like indicate an orientation or a positional relationship based on the orientation or the positional relationship shown in the drawings, and are merely for convenience and simplicity of description, and do not indicate or imply that the apparatus or element in question must be provided with a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention.

In the description of the present invention, the terms "first," "second," "third," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless explicitly specified and limited otherwise, the terms "connected," "configured," "mounted," "secured," and the like are to be construed broadly and may be either fixedly connected or detachably connected, or integrally connected, for example; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention can be understood by those skilled in the art according to the specific circumstances.

Example 1

Referring to fig. 3 and 4, the present invention discloses a heat dissipating device 15, which includes a plurality of heat dissipating fins 151.

The plurality of cooling fins 151 encircle the cylinder 2 of the container to be cooled, and are connected to the outer side wall of the cylinder 2, so as to cool the cylinder 2. The length direction of the heat sink 151 is set along the central axis direction of the cylinder 2, the width direction is set along the radial direction of the cylinder 2, the heat sink 151 is provided with a bifurcated structure on one side far away from the cylinder 2, and the bifurcated structure includes two or more bifurcated fins 153. A first flow channel is formed between two adjacent cooling fins 151, a second flow channel is formed between the branch fins 153, the cooling fins 151 are used for natural convection cooling, and in the cooling process, air flows from the lower end to the upper end of the flow channel, so that heat of the cylinder 2 is taken away.

In a nuclear power plant, the radioactive contents need to be loaded and transported by a transport container. Radioactive materials often produce radioactive decay heat, and if not timely dissipated, the temperature inside the container may rise, resulting in deformation of the container structure or reduced safety. Therefore, a radiator is required to be arranged in the transport container to effectively radiate heat generated by the radioactive objects, so that the internal temperature of the container is kept within a safe range, and the internal temperature of the container is prevented from being too high.

In the transportation process of radioactive contents, if a forced convection heat dissipation device is used for heat dissipation, a driving device is also required to be prepared, which is inconvenient. Forced convection means blowing air by a fan or the like to form a heat dissipation air flow. Fans and the like also require motors or engines and are not convenient to use during transportation. Therefore, in the present embodiment, a heat dissipating device 15 that dissipates heat by natural convection is proposed. Of course, when necessary, the heat dissipation can also be performed by adopting a combination of forced convection and natural convection.

At present, the transport container mainly adopts the straight-flow type fins as the cooling fins 151, and the straight-flow type fins have the characteristics of short flow channel, small flow resistance and high flow speed, have a simple structure, but have limited heat exchange capability on the container, limit the loading capacity of the container under the condition of ensuring the safety and the reliability of the container and the content, and have certain influence on the economy of the container. In other words, in the case of the straight-flow type rib, it is not preferable to load the transport container with excessive radioactive contents so as not to generate heat of the radioactive article beyond the load of the heat sink 151.

Aiming at the problem of low heat dissipation efficiency of the existing fins, the heat dissipation fin 151 in the embodiment is provided with a main fin 152 and a bifurcation fin 153, wherein the main fin 152 is positioned between the bifurcation fin 153 and the cylinder 2, one end of the main fin 152 is connected with the side wall of the cylinder 2, and the other end of the main fin is connected with the bifurcation fin 153. Compared with the existing straight plate type fins, the bifurcated fins can effectively increase heat exchange area and improve heat exchange efficiency. Specifically, the high heat of the radioactive substance in the cylinder 2 is transferred to the heat sink 151 by heat conduction, and the air fluid around the cylinder 2 and the heat sink 151 is heated to reduce its density, so that it generates buoyancy with respect to the surrounding cooler fluid. Thus, the hot fluid will rise and the cold fluid will sink, forming a convective loop. The convective motion of such fluids is known as natural convection. Natural convection heat transfer can take away the heat of the cartridge 2 and its radioactive contents without the need for tools such as fans to force air convection. The heat exchange area is understood to be the contact area between the air fluid and the side walls of the cylinder 2, the fins.

As shown in fig. 4, in the present embodiment, the number of the bifurcated fins 153 is two, and the cross-sectional shape of the fin 151 is Y-shaped. If the area of one side of the furcation fin 153 is set as the effective increased area, the provision of two furcation fins 153 increases the effective increased area by two. It is to be readily understood that the heat dissipating device 15 can greatly increase the heat exchanging area by providing the plurality of fins 151. When the air flows through the first flow passage and the second flow passage, heat on the side surfaces of the main fin 152 and the branching fin 153 can be taken away by means of convection heat transfer, thereby cooling the cylinder 2.

It should also be noted that the mechanism of convective heat transfer is a result of a combination of macroscopic flow of fluid, heat transfer, and heat transfer by molecular conduction in the fluid. In the thin layer of fluid close to the wall surface, heat is transferred from the plate surface to the fluid due to molecular heat conduction, so that the fluid is heated, the heated fluid simultaneously flows forwards, part of heat is taken away, the heat which is continuously transferred to the direction vertical to the plate surface is gradually reduced, and when the heat reaches the outer boundary of the boundary layer, all the heat transferred to the fluid from the wall surface is taken away by the moving fluid, so that the temperature change rate in the fluid vertical to the plate surface is close to zero, and the heat conduction in the fluid vertical to the plate surface is also zero. The fluid temperature at the wall is equal to the wall temperature and gradually decreases in a direction away from the wall until the ambient temperature.

Wherein the boundary layer means: the fluid closely attached to the object plane is adhered to the object plane, and the relative speed between the fluid and the object plane is equal to zero; in the direction away from the object plane, the velocity of the fluid increases gradually until it is equal to the free flow velocity, and this thin layer of fluid is called the boundary layer. At the adherence, the fluid velocity is zero due to the viscous effect, and the density difference is zero at the distance from the hot wall, so that a peak occurs in the fluid velocity between the hot wall and the outer boundary of the boundary layer.

Natural convection is driven by buoyancy generated by density differences, depending on the flow caused by the non-uniformity of the non-uniform temperature field of the fluid itself. Enhancing single-phase natural convection heat transfer refers to increasing the heat transfer rate of the heat transfer process. For heat exchange between the fluid and the swept-out plate, the prandtl number (Pr) of the air is about 0.7, and the flow boundary layer and the thermal boundary layer are approximately equal. Natural convection heat transfer can be characterized by the gurneff number (Gr) and rayleigh number (Ra). Wherein ra=grpr=gα _V Δtl ³ /av. Wherein Gr is a Grakoff number; pr is the Plandter number; g is gravity acceleration; alpha _v Is the thermal expansion coefficient; Δt is the temperature difference; l is the characteristic length; v is the viscosity coefficient; alpha is the thermal diffusivity.

When the rayleigh number is larger than 10e5, it is considered that the buoyancy will be larger than the viscous force, and natural convection will occur, and the larger the rayleigh number is, the more obvious the natural convection is. In this embodiment, the rayleigh number ranges from 10e6 to 10e8, so as to ensure that the heat dissipation device can be in a natural convection heat dissipation state. Preferably, the Rayleigh number of the heat dissipation device is 10e8.

Whereas the Nu-ser number (Nu) characterizing the natural convective heat transfer coefficient is positively correlated with Ra. It is therefore known from the definition of Gr and Ra that the aim of reducing the thermal resistance can be achieved by increasing the convective heat transfer coefficient and increasing the heat transfer area, keeping the material and the temperature difference unchanged. In summary, for single-phase natural convection heat transfer, the heat transfer can be enhanced by any means that can reduce boundary layers, increase turbulence of the fluid, promote mixing of the fluid portions, and increase the velocity gradient across the solid walls. The heat dissipating device 15 in this embodiment mainly increases the natural convection heat capacity by increasing the heat exchanging area.

Further, as shown in fig. 4, in the present embodiment, the thickness of the bifurcated fin 153 gradually decreases in a direction away from the main fin 152. Therefore, the thickness of the branching fins 153 of the fin 151 is small, and the heat exchange area can be greatly increased while the increase in flow resistance and thermal resistance can be avoided. The specific reasons are as follows: since any method capable of enhancing single-phase convection heat transfer inevitably causes an increase in flow resistance, the engineering is generally evaluated by a behavior evaluation criterion (PEC) for enhancing heat transfer technology. Because the air viscosity is lower, and the cooling fins 151 in this embodiment are branched, but the branches are still straight ribs, and the thickness of the branches is not large, so the additional resistance caused by the increase of the heat exchange area is not obvious, that is, the additional resistance between the fluid and the wall surface can not be introduced when the heat exchange area of the ribs is expanded or the disturbance between the fluids is increased, which means that the novel cooling fins 151 can strengthen the heat transfer under the constraint condition of PEC.

Therefore, the heat dissipating device 15 does not need to be provided with forced convection equipment, is suitable for being applied to a radioactive article transportation system, and can effectively increase the heat exchange area so as to improve the heat exchange efficiency of heat convection.

The heat exchange capacity of the fin 151 is generally evaluated by using fin efficiency in engineering, which is defined as the ratio of the actual heat dissipation capacity to the heat dissipation capacity assuming that the entire fin surface is at the temperature of the fin root, and the higher the fin efficiency, the better the heat exchange capacity of the fin. The fin efficiency is related to the fin heat conductivity, fin geometry, fin cross-sectional shape and fin surface heat transfer conditions. In general, the thermal conductivity of a fin depends on the material of the fin, and the higher the thermal conductivity of the material, the better the heat exchange performance. The fin height is often limited by geometry. The heat exchange condition of the surface of the fin needs to consider the thermal boundary layer and the flow boundary layer at the same time, and the selection of the cross section shape of the fin can influence factors such as the heat exchange area of the air flow channel and the fin at the same time.

The present embodiment is preferable in terms of geometric parameters, number, cross-sectional shape, thickness, material, etc. of the heat radiating fins 151 of the heat radiating device 15 to further improve the heat radiating performance of the heat radiating fins 151. The concrete explanation is as follows:

first, the height of the fluid walls can have a significant impact on the heat of fluid dispersion. Generally, at a location where the height of the fluid wall is low, the fluid within the boundary layer remains laminar. When the wall is high enough, the fluid will change from laminar flow to turbulent flow, and different flow conditions will have a decisive influence on heat exchange. In particular, when the fluid is in laminar flow, the heat exchange resistance is completely dependent on the thickness of the lamina (boundary layer), and the thickness of the laminar flow increases with increasing height, and at this time, the local surface heat exchange coefficient decreases with increasing height. After the wall surface is high enough to be converted into turbulent flow, the heat exchange coefficient is improved, and then the heat exchange coefficient is not changed along with the change of the height. Therefore, selecting an appropriate wall height (height of the fins 151) can improve heat dissipation efficiency. Of course, it is easy to understand that since the present heat sink 15 needs to be installed in the heat dissipation cavity of the radioactive article transport system, the two parameters of the width and the height of the heat sink 151 are limited by the overall geometry of the container, and hardly changed. Referring to fig. 4, the width a of the heat sink 151 (i.e. the dimension of the heat sink extending along the radial direction of the cylinder) is 85-95 mm, which is limited by the distance difference between the outer surface of the cylinder 2 and the inner surface of the shielding layer, and is 90mm. The height b of the heat sink 151 (i.e., the dimension of the heat sink extending along the central axis of the cylinder) is 950-1000 mm, which is limited by the distance between the upper surface of the container base 22 and the inner surface of the upper end cap body, and 970mm.

In addition, the number and thickness of the fins 151 also affect the heat exchange efficiency of the fins 151. By increasing the number of fins 151, the heat exchange area of the fins 151 can be increased, but at the same time, the distance between the fins 151 can be shortened, resulting in the interaction of the thermal boundary layers between the two fins 151. In an ideal state, the distance between two cooling fins 151 is kept to be larger than twice the distance between the fluid and the wall surface during the speed peak, the number of the cooling fins 151 is defined, a plurality of cooling fins are surrounded to form a ring shape, the included angle between every two adjacent cooling fins 151 can be 5-12 degrees, namely, the number of the cooling fins 151 can be selected to be 30-72. The thermal resistance of the heat sink 151 is defined as the ratio of the temperature difference between the substrate and the environment to the heat flow of the heat sink 151, and decreasing the thickness of the heat sink 151 decreases the thermal resistance, but also decreases the heat flow of the heat sink 151. The thickness of the heat sink 151 is selected from a range of 10-20 mm in consideration of the height of the heat sink 151 and the radius of the base 22. Preferably, the included angle between adjacent fins 151 is 10 °, i.e., the number of fins 151 is 36. As shown in fig. 4, the thickness c of the primary fin 152 in each fin 151 is 15mm.

As shown in fig. 4, in the present embodiment, the number of the bifurcated fins 153 is two, and the cross-sectional shape of the fin 151 is Y-shaped. The shape of the radiating fins 151 arranged in this way can effectively improve the heat exchange area without increasing the flow resistance and the thermal resistance, thereby improving the heat exchange efficiency. The included angle between the two bifurcation fins ranges from 15 degrees to 17 degrees. In this embodiment, the angle between the two furcation fins is 16 °. Through the contained angle between the two bifurcation fins of optimization, can guarantee also can form natural convection in the second runner between two bifurcation fins, further improve this heat abstractor's radiating efficiency.

Further, the length of the primary fin (the length upward in fig. 4 a) is 45mm, after which the primary fin is extended outward by 15 ° to form a transition section having a length of about 10mm, in other words, an angle between the plane in which the primary fin is located and the plane in which the transition section is located is 15 °. Through setting up an contained angle of 15 between changeover portion and main fin, can let the inside river basin area of bifurcation bigger a bit, more convenient processing manufacture simultaneously. If no transition is provided and the same angle is maintained, the internal area of the bifurcation will be more compact and the initial bifurcation will be more external, increasing the solids area and decreasing the fluid area, which is detrimental to air convection in the bifurcation area.

The length of the furcation fin (length up in fig. 4 a) is 35mm such that the overall ratio of primary fin to furcation fin length is approximately 1:1. through the length proportion between reasonable setting main fin and the bifurcation fin, can be convenient for process when guaranteeing the heat transfer effect. The greater the specific gravity of the primary fins, the closer to the straight ribs, and the less pronounced the heat dissipation effect optimization. If the specific gravity of the forked body is large, the smaller the included angle of the forked fins is, firstly, the structure is unstable, secondly, the machining can be difficult, an excessively small acute angle can be formed, and the heat exchange effect is not increased obviously.

In this embodiment, the heat sink 151 material is made of stainless steel material. Since the heat sink 151 is required to have high structural strength when applied to a transportation system for radioactive goods, the heat sink 151 is made of stainless steel material in consideration of the heat conductivity, structural strength requirements and cost factors. Preferably, the heat sink 151 may be integrally formed with the cylinder 2 to improve heat transfer efficiency between the heat sink 151 and the cylinder 2.

Referring to fig. 1 and 2, the heat dissipating device 15 in the present embodiment is suitable for a transportation container of radioactive articles, and is used for effectively removing heat generated by a radioactive content heat source through natural convection under various working conditions. The cooling fin 151 is located in the cooling cavity between the shell 1 and the cylinder 2 of the transport container, and the cooling fin 151 surrounds the cylinder 2 and is connected with the outer side wall of the cylinder 2. A certain gap is left between the outer edge of the branch fins 153 of the radiating fins 151 and the inner side wall of the heat insulation layer of the shell 1, so that air fluid can flow upwards along the annular radiating cavity conveniently, and heat of the radiating fins 151 is taken away. Specifically, air enters the heat dissipation cavity from the bottom of the cylinder 2, flows upwards through a flow channel formed between the heat dissipation fins 151 and the annular heat dissipation cavity, carries out natural convection to take away heat, and finally flows out from the top of the heat dissipation cavity.

In summary, the heat dissipating device 15 has the following advantages:

1. the heat dissipation device 15 adopts the heat dissipation fins 151 with fractal structures, so that the heat exchange area can be effectively increased, the fin efficiency can be improved, and the heat dissipation efficiency of the fins can be improved;

2. the transportation container can be ensured to carry the heat source in the content out of the container under various working conditions without any manual interference without a forced convection device, so that the temperature and the pressure of each part in the container are ensured to be at a lower level, and the requirements of the radioactive article safety transportation regulations are met;

3. the design of the novel cooling fins 151 in the cooling device 15 not only meets the temperature limiting requirement of the container, but also increases the loading capacity of the content, and effectively improves the economic applicability and the safety reliability of the transportation container;

4. compared with the straight ribs (direct-current ribs), the novel cooling fin 151 achieves better cooling effect and smaller volume, saves materials and reduces manufacturing cost.

Example 2

Referring to fig. 1 and 2, the present invention also discloses a radioactive article transport system, which includes a housing 1, a cylinder 2, and a heat dissipating device 15 in embodiment 1.

Wherein, shell 1 includes heat preservation lateral wall, fire prevention lid 6 and base 22, and fire prevention lid 6 and base 22 are connected with the upper and lower both ends of heat preservation lateral wall respectively, are provided with first convection mouth on the fire prevention lid 6, correspond on the base 22 and set up the second convection mouth. The cylinder 2 is located inside the housing 1 and mounted on a base 22. The barrel 2 is a sealing structure and is used for placing radioactive articles, a heat dissipation cavity is arranged between the outer wall of the barrel 2 and the heat preservation side wall, the heat dissipation cavity is annular and surrounds the barrel 2, the upper end and the lower end of the heat dissipation cavity are respectively communicated with a first convection opening and a second convection opening, and air flows into the heat dissipation cavity from the second convection opening and flows out of the heat dissipation cavity from the first convection opening. The heat dissipating device 15 is located in the heat dissipating cavity, and the heat dissipating fins 151 of the heat dissipating device 15 are connected to the outer side wall of the cylinder 2, and are used for naturally and convectively dissipating heat of the cylinder 2.

The radioactive article transport system needs to ensure that the temperature of the radioactive articles inside the radioactive article transport system is kept within a proper range, and the side wall (namely the heat-preserving side wall) of the radioactive article transport system is provided with a heat-preserving layer for avoiding the influence of external temperature change on radioactive substances inside the container. The insulation layer is typically made of an insulating material, such as a heat insulating material or a heat insulating material, for the purpose of reducing heat conduction and dissipation and maintaining the temperature inside the container stable. In addition, the outer layer of the heat-insulating side wall is also provided with a fireproof sleeve 8, and the fireproof sleeve 8 is used for isolating an external heat source in the case of fire accidents.

In addition, the container is easily damaged due to the excessively high temperature in the cylinder 2, and the storage of the radioactive article is not facilitated, so that a radiator is required to be arranged in the transportation system. In transportation systems, natural convection heat dissipation is generally used. Taking a transport container of radioactive cobalt source as an example, the cobalt source is positioned and installed in the cylinder 2. Assuming that 16 cobalt-60 bars of 1.4 ten thousand curies are loaded, the diameter of each bar is 11.1mm, the length is 452mm, and the total volume of the contents can be converted to 6.99X10-4 m ³ . The total power was 3328W. Conventional straight ribs are simply inadequate to meet such high heat dissipation requirements.

In order to achieve the heat dissipation purpose of the radioactive article, in this embodiment, the heat dissipation device 15 adopts a bifurcated heat dissipation fin 151, the heat dissipation fin 151 is located in a heat dissipation cavity between the housing 1 and the cylinder 2 of the transport container, and the heat dissipation fin 151 surrounds the cylinder 2 and is connected with an outer side wall of the cylinder 2. A certain gap is left between the outer edge of the branch fins 153 of the radiating fins 151 and the inner side wall of the heat insulation layer of the shell 1, so that air fluid can flow upwards along the annular radiating cavity conveniently, and heat of the radiating fins 151 is taken away. In this embodiment, the shapes of the first convection port and the second convection port may be set to be annular to correspond to the shape of the heat dissipation cavity. The heat dissipation cavity is communicated with the outside through the first convection port and the second convection port. Specifically, air enters the heat dissipation cavity from the second convection opening at the bottom of the cylinder 2, flows upwards through the flow channel formed between the heat dissipation fins 151 and the annular heat dissipation cavity, carries out natural convection to take away heat, and finally flows out from the first convection opening at the top of the heat dissipation cavity.

Continuing to take the transport vessel of the radioactive cobalt source as an example, the medium flow rate in the flow channel ranges from 0.0047 to 1m/s under steady state conditions of 38 degrees of solar insolation. The heat dissipation device 15 can meet the heat dissipation requirement of the cobalt source transportation container through calculation.

Referring to fig. 2, the cylinder 2 includes an outer cylinder 3 and an inner cylinder 4, a heat sink 151 of a heat dissipating device 15 is connected to an outer side wall of the outer cylinder 3, the inner cylinder 4 is accommodated inside the outer cylinder 3 and is disposed along the same vertical central axis with the outer cylinder 3, an upper end of the inner cylinder 4 is connected to an upper end of the outer cylinder 3, and the inner cylinder 4 is used for placing a radioactive object. The inner cylinder 4 contains water for primary shielding of the radiation of the radioactive article. Further, a lead-filled layer 14 is provided between the outer cylinder 3 and the inner cylinder 4 for secondarily shielding the radiation of the radioactive article. The cylinder 2 further comprises a shielding plug 5, and the shielding plug 5 is arranged at the opening of the upper end of the inner cylinder 4 and is used for sealing the opening of the upper end of the inner cylinder 4.

Specifically, an upper forging 9 for welding and fixing the inner cylinder 4 is mounted on the upper portion of the outer cylinder 3. An upper angle plate 10 and an upper access plate 11 are further arranged on the inner side of the outer cylinder 3, and the upper angle plate 10 and the upper access plate 11 are fixedly connected with the upper forging 9. Refractory filler 12 is filled between the upper gusset 10 and the upper access panel 11 to prevent the radioactive articles in the inner cylinder 4 from radiating too high heat to cause fire. A lifting lug 13 is fixedly arranged above the upper angle plate 10, the lifting lug 13 is used for fixedly arranging a hanging basket 7, and the hanging basket 7 is accommodated in the inner barrel 4 and used for positioning radioactive contents.

More specifically, since the inner cylinder 4 is filled with the isolation water, in order to facilitate replacement of the isolation water therein, the lower end of the inner cylinder 4 is provided with a first water outlet, the side wall of the lower end of the outer cylinder 3 is provided with a second water outlet, the transportation system is further provided with a drain pipe 16, one end of the drain pipe is communicated with the first water outlet, and the other end is communicated with the second water outlet. The second drain opening is provided with a cover plate groove 17, a drain opening hole cover 18 is arranged on the inner side of the cover plate groove 17, and the drain opening hole cover 18 is used for sealing the second drain opening. When the isolation water in the inner tube 4 needs to be discharged, the drain hole cover 18 is opened, and the isolation water can be discharged through the second drain hole.

The lower end of the outer tube 3 is further provided with a bottom pad 19, and the bottom pad 19 is connected to the lower end of the lead filling layer 14 to fix the lead filling layer 14. An underfill 21 is filled between the underfill 19 and the outer tub floor 20, and the underfill 21 is also a refractory filler 12.

In this embodiment, a gap exists between the vertical outer edge of the heat sink 151 and the heat-retaining side wall of the housing 1 to leave an air flow passage. The air flow channel is an annular channel, namely a channel formed by a plurality of first flow channels, a plurality of second flow channels and an annular heat dissipation cavity of the heat dissipation device 15, and air fluid enters the heat dissipation cavity through a second convection opening at the lower end and flows through the air flow channel to take away heat of the heat dissipation fins 151 through convection heat transfer. Therefore, the heat sink 151 may effectively remove heat generated by the internal heat source through natural convection under various conditions. The radiating fins 151 are of stainless steel structures, 30-72 radiating fins can be adopted and are sequentially connected to the outer side of the outer surface of the container cylinder 2 at intervals, and a certain gap is reserved between the other end of each radiating fin and the inner side of the heat preservation layer, so that air can flow in an annular axial direction conveniently. One of the cooling fins 151 needs to be cut short to avoid the drain pipe 16, a certain space is reserved for the drain outlet and the drain pipe 16, and air enters the cooling fin 151 from the bottom of the cylinder 2 to carry away heat by natural convection and flows out from the top of the container after passing through a flow channel formed by the cooling fins 151.

In summary, the radiation article transporting system has higher radiation efficiency by adopting the radiation device 15 in embodiment 1, so that more radiation articles can be accommodated, the loading capacity of the content is increased, and the economic applicability and the safety reliability are effectively improved.

It is to be understood that the above embodiments are merely illustrative of the application of the principles of the present invention, but not in limitation thereof. Various modifications and improvements may be made by those skilled in the art without departing from the spirit and substance of the invention, and are also considered to be within the scope of the invention.

Claims (10)

1. A heat sink, comprising: a plurality of fins (151);

the cooling fins (151) encircle the periphery of the cylinder (2) to be cooled and are connected with the outer side wall of the cylinder (2) to cool the cylinder (2);

the length direction of the radiating fins (151) is arranged along the central axis direction of the cylinder body (2), the width direction of the radiating fins is arranged along the radial direction of the cylinder body (2), a bifurcation structure is arranged on one side, far away from the cylinder body (2), of the radiating fins (151), and the bifurcation structure comprises two or more bifurcation fins (153);

a first flow channel is formed between two adjacent radiating fins (151), a second flow channel is formed between the branch fins (153), the radiating fins (151) are used for carrying out natural convection radiation, and air flows from the lower ends of the first flow channels and the second flow channels to the upper ends, so that heat of the cylinder body (2) is taken away.

2. The device according to claim 1, characterized in that the heat sink (151) further comprises a main fin (152), the main fin (152) being located between the furcation fin (153) and the cylinder (2), one end of which is connected to the side wall of the cylinder (2) and the other end of which is connected to the furcation fin (153).

3. The device according to claim 2, wherein the number of the bifurcated fins (153) is two, and the cross-sectional shape of the heat sink (151) is Y-shaped.

4. A device according to claim 3, characterized in that the thickness of the furcation fin (153) decreases gradually in a direction away from the main fin (152).

5. A device according to any one of claims 1-4, characterized in that a plurality of said fins are arranged in a ring shape, the angle between adjacent fins (151) being in the range of 5-12 °, the thickness of the primary fins (152) in each fin (151) being in the range of 10-20 mm.

6. The device according to any one of claims 1-4, characterized in that the heat sink (151) material is made of stainless steel material.

7. A radioactive article transport system characterized by comprising a housing (1), a cylinder (2) and a heat dissipating device (15) according to any of claims 1-6,

the shell (1) comprises a heat-preserving side wall, a fireproof cover (6) and a base (22), wherein the fireproof cover (6) and the base (22) are respectively connected with the upper end and the lower end of the heat-preserving side wall, a first convection opening is arranged on the fireproof cover (6), a second convection opening is correspondingly arranged on the base (22),

the barrel body (2) is positioned in the shell (1) and is arranged on the base (22), the barrel body (2) is of a sealing structure and is used for placing radioactive objects, a heat dissipation cavity is arranged between the outer side wall of the barrel body (2) and the heat preservation side wall, the heat dissipation cavity is annular and surrounds the barrel body (2), the upper end and the lower end of the heat dissipation cavity are respectively communicated with the first convection opening and the second convection opening, and air flows into the heat dissipation cavity from the second convection opening and flows out of the heat dissipation cavity from the first convection opening;

the heat dissipation device is positioned in the heat dissipation cavity, and heat dissipation fins (151) of the heat dissipation device are connected with the outer side wall of the cylinder body (2) and used for naturally carrying out convection heat dissipation on the cylinder body (2).

8. The system according to claim 7, wherein the cylinder (2) comprises an outer cylinder (3) and an inner cylinder (4), the cooling fins (151) of the cooling device are connected with the outer side wall of the outer cylinder (3), the inner cylinder (4) is accommodated inside the outer cylinder (3) and is placed along the same vertical central axis as the outer cylinder (3), the upper end of the inner cylinder (4) is connected with the upper end of the outer cylinder (3), and the inner cylinder (4) is used for placing radioactive objects;

the inner cylinder (4) is filled with isolation water, and the isolation water is used for shielding the radiation of the radioactive articles once.

9. The system according to claim 8, characterized in that a layer of filled lead (14) is provided between the outer cylinder (3) and the inner cylinder (4) for secondary shielding of the radiation of the radioactive article;

the cylinder body (2) further comprises a shielding plug (5), and the shielding plug (5) is arranged at the opening of the upper end of the inner cylinder (4) and is used for sealing the opening of the upper end of the inner cylinder (4).

10. The system of claim 7, wherein a gap exists between the vertically outer edges of the fins (151) and the insulated side walls of the housing to allow for an airflow passage.