CN209216591U - A heat pipe-type dual-mode space nuclear reactor core with radial hydrogen flow channels - Google Patents

Abstract

The utility model belongs to the technical field of reactor engineering and discloses a heat pipe type dual-mode space nuclear reactor core adopting a radial hydrogen flow channel. The reactor core includes a radial reflective layer, a core active area, a heat pipe, a core barrel, an axial reflective layer, and a control drum, wherein the core active area is located in the core barrel, and the axial reflective layer is located in the core active area. Above; the radial reflection layer is a hollow cylindrical structure, and the active area of the core, the axial reflection layer and the heat pipe are located in the cavity of the radial reflection layer; the utility model has the advantages of simple structure, high operation safety and reliability and has Beneficial effects of passive, non-single point of failure advantages.

Description

A heat pipe-type dual-mode space nuclear reactor core with radial hydrogen flow channels

technical field

The utility model belongs to the technical field of reactor engineering, in particular to a heat pipe type dual-mode space nuclear reactor core adopting a radial hydrogen flow channel.

Background technique

Dual-mode space nuclear reactors have the functions of propulsion and power generation at the same time, combining many advantages of nuclear thermal propulsion reactors and space reactor power sources over conventional energy sources. The reactor is very suitable for manned moon landing, manned Mars, space transportation and other missions.

The United States, Russia and other space powers have carried out extensive research on dual-mode reactors, and proposed three types of dual-mode reactors: one is the dual-mode reactor scheme based on thermionic reactors. In this scheme, the central channel of the thermionic fuel element serves as a heating channel for the hydrogen working fluid. In propulsion mode, hydrogen flows through the fuel center hole from top to bottom, heated and then discharged, thereby generating thrust, and at the same time, thermionic fuel elements can generate electrical energy; in power generation mode, the thermal power of the core is relatively low, and the system will stop the hydrogen Discharge, no longer generate thrust, only generate electricity by thermionic fuel elements, and waste heat is taken out of the core by the sodium-potassium circuit; the second is a dual-mode reactor scheme based on the NERVA nuclear thermal propulsion reactor. In this solution, the composite fuel elements in the core are used as fuel elements for propulsion, and the cooling circuit of the supporting elements in the core is used as a power generation circuit. In the propulsion mode, the hydrogen working fluid flows through the heating channel in the composite fuel element from top to bottom, and is discharged from the nozzle after being heated to generate thrust. In the power generation mode, the thermal power of the core is relatively low, the system will stop hydrogen emission, and no longer generate thrust. The heat generated by the composite fuel element is transferred to the support element by heat conduction, and is located at The cooling circuits in the support elements are led to Stirling generators outside the stack to generate electricity. The third is a dual-mode reactor scheme based on a heat pipe reactor. In this scheme, a number of heat pipes are arranged inside the core to export heat for power generation. In the propulsion mode, the hydrogen working fluid flows through the heating channel in the fuel element from top to bottom, and is discharged from the nozzle after heating to generate thrust. At the same time, the heat pipe conducts part of the core heat to the outside of the stack for power generation; in the power generation mode, The thermal power of the core is relatively low, the system will stop hydrogen discharge, no longer generate thrust, the heat generated by the fuel elements will be exported by the heat pipe, and generate electricity outside the stack.

There are deficiencies in the above three types of dual-mode reactor schemes. The first two types of schemes both need to arrange a much lower temperature working fluid circuit in the ultra-high temperature nuclear thermal propulsion reactor, and require many components such as pumps and volume compensators. The system is complex, difficult to develop, and does not have passive , non-single point of failure, etc. The third type of scheme uses heat pipes to export heat out of the core for power generation. It has a relatively simple structure, has the advantages of passive, non-single-point failure, and high reliability. However, heat pipes also present new problems for system design: In propulsion mode, the heat pipes must operate well below the maximum temperature of the fuel to avoid damage to the heat pipes due to overheating. In order to solve this problem, a double-layer shell structure is arranged between the heat pipe and the fuel to separate the two. In the propulsion mode, there is a vacuum between the double-layer shell to increase the distance between the fuel and the heat pipe. In order to protect the heat pipe; in power generation mode, the double-layer shell is filled with helium to minimize the thermal resistance between the fuel and the heat pipe, so as to enhance the heat transfer performance between the two . This method increases the complexity and difficulty of development of the system, and reduces the reliability of the system when it is running. Therefore, there is an urgent need to develop a dual-mode space nuclear reactor with passive, non-single-point failure, simple structure, and stable system operation.

Utility model content

(1) Purpose of utility model

According to the problems existing in the prior art, the utility model provides a dual-mode space nuclear reactor core with simple structure, high operation safety and reliability, and the advantages of passive and non-single-point failure.

(2) Technical solutions

In order to solve the existing problems of the prior art, the technical solution provided by the utility model is as follows:

A heat pipe type dual-mode space nuclear reactor core adopting radial hydrogen flow channels, the reactor core includes a radial reflective layer, a core active area, a heat pipe, a core cylinder, an axial reflective layer, and a control drum, wherein the reactor The core active area is located in the core barrel, and the axial reflective layer is located above the core active area; the radial reflective layer is a hollow cylindrical structure, and the core active area, axial reflective layer and heat pipe are located in the cavity of the radial reflective layer Inside;

The material of the main structure of the radial reflective layer is beryllium oxide, and a plurality of uniformly distributed control drums are arranged in the radial reflective layer, wherein the shape of the control drum is cylindrical, and the length is consistent with the length of the radial reflective layer Rotating into the reflective layer, each control drum is provided with an absorber with a radian of 120 degrees along the circumference. The absorber extends from the top of the control drum to the bottom of the control drum. The demand for propulsion and electric energy; except for the absorber body, the material of the rest of the control drum is consistent with that of the main structure of the radial reflection layer, all of which are beryllium oxide and there are through holes on the beryllium oxide, which are used for hydrogen circulation the first runner;

An axial reflective layer is arranged above the core active area, and a hole for hydrogen gas circulation is arranged in the axial reflective layer, and this hole is used as a second flow channel for hydrogen gas flow; A gap of 5-10 mm is used for the third flow channel for hydrogen gas circulation; the core active area is located inside the core barrel, and a fourth flow channel for hydrogen gas circulation is left between the core active area and the core barrel ;

The core active area mainly includes a plurality of circular fuel plates stacked up and down, and the fuel type is tungsten-based cermet fuel; except for the fuel plate at the top, the rest of the fuel plates are provided with a central hole and a supporting structure, wherein The center hole is located at the geometric center, and the support structure is composed of multiple support plates, each of which is arc-shaped. The multiple support plates are evenly distributed along the center hole, and the length is the distance from the periphery of the center hole to the periphery of the fuel plate. The setting of the support plate makes the fifth flow passage for hydrogen radially circulated between the fuel plates, and the hydrogen flows from the outside to the inside in the fifth radial flow passage to cool the fuel, and finally enters the central hole to flow out;

The axial reflective layer is a disk-shaped structure made of beryllium oxide, and its diameter is consistent with the inner diameter of the core cylinder; the axial reflective layer and each fuel plate are provided with a plurality of heat pipe guide holes at corresponding positions, It is used to place the heat pipe, which extends from above the axial reflection layer to the bottom of the core active area;

Preferably, the basic component of the tungsten-based cermet fuel is a mixture of tungsten and uranium dioxide, and its outer surface is provided with a tungsten-rhenium alloy coating.

Preferably, the working fluid in the heat pipe is lithium, and the material of the heat pipe is tungsten-rhenium alloy.

Preferably, the core barrel is made of tungsten-rhenium alloy.

Preferably, the height of the axial reflection layer is located above the active area of the core, and is higher than the height of the radial reflection layer of the core in the height direction.

Preferably, the bottom of the heat pipe extends to the bottom of the active area of the core, and the top extends out of the axial reflection layer and is connected to the thermoelectric conversion device.

Preferably, the absorber is made of boron carbide.

Preferably, the position and number of the heat pipe guide holes on the fuel plate are determined according to the operating temperature of the heat pipe and the electric power requirement.

(3) Beneficial effects

Adopting the dual-mode space nuclear reactor core provided by the utility model, the reactor core adopts a plurality of fuel plates superimposed up and down to form the active area of the core for the first time, and a support structure arranged along the central hole is arranged between the fuel plates so that there are The holes for hydrogen flow allow hydrogen to flow radially in the core active area instead of up and down. This flow mode makes the temperature of the fuel plate in the active area increase radially from outside to inside and the temperature distribution in the axial direction is relatively uniform. At the same time, the heat pipe The temperature control of the fuel tank becomes simple, and the heat pipe can be arranged in the fuel area matching its operating temperature to avoid overheating.

In the dual-mode reactor scheme in a traditional heat pipe reactor, when the reactor switches from the propulsion mode to the power generation mode, it needs to continue to discharge hydrogen for a period of time until the fuel temperature drops to a certain level before stopping the hydrogen discharge, so as to avoid power generation system or heat pipe. Damaged by overheating, on the one hand, it causes a waste of hydrogen working fluid and reduces the overall specific impulse performance of the system; on the other hand, it also brings unnecessary troubles to the control of the spacecraft. In this application, the heat pipe is arranged in the area where the heat pipe can withstand the temperature. The calculation shows that when switching from the propulsion mode to the power generation mode, the hydrogen emission can be stopped immediately, and the temperature fluctuation of the fuel area where the heat pipe is located is not large. Damage to heat pipes or power generation systems.

Description of drawings

Figure 1 is a schematic diagram of the axial section of the core;

Fig. 2 is a schematic diagram of a circular fuel plate;

Figure 3 is an overall schematic diagram of the core active area containing the topmost fuel plate;

Fig. 4 is the overall schematic diagram of the active zone of the core without the top fuel plate;

Figure 5 is a schematic cross-sectional view of the core;

Fig. 6 is a schematic diagram of the axial section of the core and the flow path of hydrogen;

Figure 7 is an overall schematic diagram of the core;

Among them, 1 is the fuel plate; 2 is the support plate; 3 is the center hole; 4 is the heat pipe guide hole; 5 is the active area of the core; 6 is the heat pipe; 7 is the axial reflection layer; 10 is the control drum; 11 is the absorber; 12 is the hydrogen channel arranged in the radial reflector layer; 13 is the hydrogen channel arranged in the control drum; 14 is the fourth flow channel; 15 is the fifth flow channel; 16 is the second runner; 17 is the third runner.

Detailed ways

The present application will be further elaborated below in conjunction with the accompanying drawings and specific implementation methods.

A heat pipe-type dual-mode space nuclear reactor core adopting radial hydrogen flow channels, as shown in Fig. 1 to Fig. 7 . The reactor includes a radial reflector 9, a core active area 5, a heat pipe 6, a core barrel 8, an axial reflector 7, and a control drum 10, wherein the core active area 5 is located in the core barrel 8, and the axial The reflective layer 7 is located above the core active area 5; the radial reflective layer 9 is a hollow cylindrical structure, and the core active area 5, the axial reflective layer 7 and the heat pipe 6 are located in the cavity of the radial reflective layer 9;

The material of the main structure of the radial reflection layer 9 is beryllium oxide, and a plurality of uniformly distributed control drums 10 are arranged in the radial reflection layer 9, wherein the shape of the control drums 10 is cylindrical, and the length is the same as that of the radial reflection layer 9. The length is consistent and can rotate in the radial reflection layer 9, and the absorber 11 with a radian of 120 degrees is arranged in each control drum 10 along the circumference, and the absorber 11 extends from the top of the control drum 10 to the bottom of the control drum 10, absorbing The body 11 rotates with the control drum 10 to the required angle to make the reactor reach the state of critical operation; in the control drum 10, except for the absorber 11, the material of the remaining parts is consistent with that of the main structure of the radial reflection layer, all of which are beryllium oxide and The beryllium oxide is provided with a through first flow channel for the circulation of hydrogen, and the hydrogen flows in from bottom to top through the first flow channel to cool the radial reflection layer and the control drum, while the hydrogen is also preheated during this process.

The top of the core active area 5 is provided with an axial reflective layer 7, and a plurality of through holes are arranged in the axial reflective layer 7, and the holes are used as the second flow channel for hydrogen to flow; the axial reflective layer 7 and the core There is a gap of 5-10 mm at the top of the active area 5, which is used for the third flow channel for hydrogen circulation; the core active area 5 is located inside the core barrel 8, and the gap between the core active area 5 and the core barrel 8 There is a fourth flow channel for hydrogen circulation in between;

The core active area 5 mainly includes a plurality of circular fuel flat plates 1 stacked up and down, and the structural diagram of the fuel flat plates 1 is shown in FIG. 2 . The fuel type is tungsten-based cermet fuel, the basic composition is a mixture of tungsten and uranium dioxide, and its outer surface is provided with a tungsten-rhenium alloy coating. Except for the fuel plate at the top, all other fuel plates are provided with a central hole 3 and a support structure, wherein the central hole 3 is located at the geometric center, and the support structure is composed of a plurality of support plates 2, each of which has a shape of The plurality of support plates 2 are evenly distributed along the central hole 3, and the length is the distance from the outer periphery of the central hole to the outer periphery of the fuel flat plate 1; the support plates 2 are set so that there is a fifth space for the radial flow of hydrogen gas between the fuel flat plates 1. In the flow channel, the hydrogen flows from the outside to the inside in the fifth radial flow channel to cool the fuel, and finally enters the central hole 3 and then flows out;

The axial reflective layer 7 is a disk-shaped structure made of beryllium oxide, and its diameter is consistent with the inner diameter of the core cylinder 8; the corresponding positions of the axial reflective layer 7 and each fuel plate 1 are provided with a plurality of The heat pipe guide hole 4 is used to place the heat pipe 6, and the heat pipe 6 extends from above the axial reflection layer 7 to the bottom of the core active area 5;

The working medium in the heat pipe 6 is lithium, and the material of the heat pipe 6 is tungsten-rhenium alloy. The core barrel is made of tungsten-rhenium alloy. The height of the axial reflection layer is located above the active area of the core, and is higher than the height of the radial reflection layer of the core in the height direction. The bottom of the heat pipe extends to the bottom of the active area of the core, and the top extends out of the axial reflection layer and is connected with the thermoelectric conversion device.

The absorber 11 is made of boron carbide. The position and number of the heat pipe guide holes 4 on the fuel plate 1 are determined according to the operating temperature of the heat pipe and the electric power requirement.

Utilizing the dual-mode reactor provided by the utility model, in the propulsion mode, the hydrogen working medium first flows through the radial reflective layer and the first channel in the control drum from bottom to top to cool the radial reflective layer 9 and the control drum 10, At the same time, it acts as a preheater for the hydrogen. After that, the hydrogen working fluid flows through the second flow channel 16 in the axial reflection layer, the third flow channel 17 between the top of the core active area and the axial reflection layer, and the active area and the core tube from top to bottom. The fourth flow channel 14 between the fuel plates then enters the fifth flow channel of the radial hydrogen flow channel between the fuel plates, flows from outside to inside in the radial flow channel and cools the fuel, then enters the center hole 3 of the fuel, and is finally formed by The bottom of the core is discharged through the nozzle to generate thrust. At the same time, in this mode, part of the thermal power of the core will be exported by the heat pipe 6, and electric energy will be generated outside the stack through Stirling power generation or static temperature difference power generation.

In power generation mode, the thermal power of the core is relatively low, the hydrogen working medium will stop discharging, all the heat of the core is exported by the heat pipe 6, and electricity is generated outside the core by means of Stirling power generation or static temperature difference power generation.

Claims (8)

1. A heat pipe type dual-mode space nuclear reactor core adopting radial hydrogen flow channels, characterized in that, the reactor core comprises a radial reflection layer, a core active region, heat pipes, a core shell, and an axial reflection layer , control drum, wherein the core active area is located in the core barrel, the axial reflective layer is located above the core active area; the radial reflective layer is a hollow cylindrical structure, and the core active area, axial reflective layer and heat pipe are located on the diameter into the cavity of the reflective layer; The material of the main structure of the radial reflective layer is beryllium oxide, and a plurality of uniformly distributed control drums are arranged in the radial reflective layer, wherein the shape of the control drum is cylindrical, and the length is consistent with the length of the radial reflective layer Rotating into the reflective layer, each control drum is provided with an absorber with a radian of 120 degrees along the circumference. The absorber extends from the top of the control drum to the bottom of the control drum. The demand for propulsion and electric energy; except for the absorber body, the material of the rest of the control drum is consistent with that of the main structure of the radial reflection layer, all of which are beryllium oxide and there are through holes on the beryllium oxide, which are used for hydrogen circulation the first runner; An axial reflective layer is arranged above the core active area, and a hole for hydrogen gas circulation is arranged in the axial reflective layer, and this hole is used as a second flow channel for hydrogen gas flow; A gap of 5-10 mm is used for the third flow channel for hydrogen gas circulation; the core active area is located inside the core barrel, and a fourth flow channel for hydrogen gas circulation is left between the core active area and the core barrel ; The core active area mainly includes a plurality of circular fuel plates stacked up and down, and the fuel type is tungsten-based cermet fuel; except for the fuel plate at the top, the rest of the fuel plates are provided with a central hole and a supporting structure, wherein The center hole is located at the geometric center, and the support structure is composed of multiple support plates, each of which is arc-shaped. The multiple support plates are evenly distributed along the center hole, and the length is the distance from the periphery of the center hole to the periphery of the fuel plate. The setting of the support plate makes the fifth flow passage for hydrogen radially circulated between the fuel plates, and the hydrogen flows from the outside to the inside in the fifth radial flow passage to cool the fuel, and finally enters the central hole to flow out; The axial reflective layer is a disk-shaped structure made of beryllium oxide, and its diameter is consistent with the inner diameter of the core cylinder; the axial reflective layer and each fuel plate are provided with a plurality of heat pipe guide holes at corresponding positions, It is used to place heat pipes, which extend from above the axial reflection layer to the bottom of the active area of the core. 2. A heat pipe type dual-mode space nuclear reactor core adopting radial hydrogen flow channels according to claim 1, wherein the basic composition of the tungsten-based cermet fuel is a mixture of tungsten and uranium dioxide , the outer surface of which is provided with a tungsten-rhenium alloy coating. 3. A heat pipe type dual-mode space nuclear reactor core adopting radial hydrogen flow channels according to claim 1, wherein the working medium in the heat pipe is lithium, and the material of the heat pipe is tungsten-rhenium alloy. 4 . The core of a heat pipe dual-mode space nuclear reactor adopting radial hydrogen flow channels according to claim 1 , wherein the core cylinder is made of tungsten-rhenium alloy. 5. A kind of heat pipe type dual-mode space nuclear reactor core that adopts radial hydrogen flow channel according to claim 1, it is characterized in that, the height of described axial reflective layer is positioned at above core active area, and it is in height direction The height above the radial reflector of the core. 6. A heat pipe type dual-mode space nuclear reactor core adopting radial hydrogen flow channels according to claim 1, wherein the bottom of the heat pipe extends into the bottom of the core active area, and the top extends out of the axial direction. The reflection layer is connected with the thermoelectric conversion device. 7 . A heat pipe type dual-mode space nuclear reactor core adopting radial hydrogen flow channels according to claim 1 , wherein the absorber is made of boron carbide. 8. A kind of heat pipe type dual-mode space nuclear reactor core adopting radial hydrogen flow channel according to claim 1, characterized in that, the position and number of heat pipe guide holes on the fuel plate are determined according to heat pipe operating temperature and electric power demand .