Alkali metal seed injection system for shock tube magnetohydrodynamic power generation

Abstract

The invention relates to the technical field of high-temperature gas magnetohydrodynamic power generation, in particular to an alkali metal seed injection system for shock tube magnetohydrodynamic power generation. Comprising a temperature-controllable heater which is arranged on the outer side wall of the low-pressure section working area of the shock tube and can heat the low-pressure section working area of the shock tube, so that the alkali metal seeds falling into the low-pressure section working area of the shock tube are rapidly evaporated and gasified. The internal mixing type alkali metal seed injection system is used, the alkali metal seeds can be gasified in a working area and directly mixed with inert gas, the alkali metal seeds are arranged in the alkali metal glass bulb, and the total amount of the alkali metal seeds can be kept unchanged during gasification and mixing with the inert gas; therefore, the alkali metal seeds can be accurately metered. The alkali metal seeds are directly mixed with gasified alkali metal seeds in a low-pressure section working area, and compared with an external premixing and filling type alkali metal seed injection system, the problem of alkali metal seed loss does not exist.

Description

Technical Field

[0001] The invention relates to the technical field of high-temperature gas magnetohydrodynamic power generation, and in particular to an alkali metal seed injection system for shock tube magnetohydrodynamic power generation. Background Art

[0002] Magnetohydrodynamic power generation is a new type of power generation that directly converts thermal energy into electrical energy. It began in the late 1950s, and its basic working principle is still Faraday's law of electromagnetic induction. Unlike traditional power generation, it uses conductive fluid instead of conductive solid to conduct electricity, and makes the conductive fluid pass through a magnetic field perpendicular to the flow direction at a certain speed, cutting the magnetic lines of force to induce electromotive force, thereby generating electrical energy.

[0003] According to the different conductive fluids used, magnetohydrodynamic power generation can be divided into combustion gas plasma magnetohydrodynamic power generation, inert gas plasma power generation and liquid metal magnetohydrodynamic power generation. When using nuclear energy as a heat source, the use of inert gas plasma power generation is an important method.

[0004] In the inert gas plasma power generation method, in order to make the inert gas working fluid obtain a sufficiently high conductivity, a small amount of alkali metal ionization seeds need to be injected into the working fluid, and the seeds need to be evenly distributed and quickly heated, vaporized and fully ionized when injected into the fluid working fluid. Therefore, the injection system needs to accurately control and measure the amount of injected seeds, and also needs to make the seeds evenly mixed with the mainstream of the inert gas, quickly heated, fully vaporized and ionized. However, since pure alkali metals are extremely chemically active and easily react chemically with most substances, especially with water, the requirements for their injection system are relatively stringent.

[0005] Most common seed injection systems currently use an external heating device to first evaporate and gasify the alkali metal seeds, then form a mixed vapor with the carrier gas, and then enter the low-pressure working area of ​​the shock tube through a series of components such as the gas injection pipeline and valve. However, in this way, the mixed gas of the carrier gas and the alkali metal vapor needs to pass through metal pipelines and valves before entering the shock tube. During the transportation process, part of the alkali metal vapor will condense into liquid, part will adhere to the wall of the metal pipeline, and part will remain inside the heating tank. On the one hand, the expensive alkali metal seeds are wasted, and on the other hand, the amount of seeds entering the shock tube cannot be accurately measured, which affects the power generation performance of the shock tube magnetohydrodynamic generator. Summary of the invention

[0006] In view of this, the present invention provides an alkali metal seed injection system for shock tube magnetohydrodynamic power generation to solve the problems of alkali metal seed loss and inability to accurately measure the amount of seeds in the existing seed injection system.

[0007] The present invention provides an alkali metal seed injection system for shock tube magnetohydrodynamic power generation, which is used to inject alkali metal seeds into the low-pressure section working area of ​​the shock tube, comprising:

[0008] A controllable temperature heater is arranged on the outer side wall of the low-pressure section working area of ​​the shock tube, and can heat the low-pressure section working area of ​​the shock tube, so that the alkali metal seeds falling into the low-pressure section working area of ​​the shock tube are rapidly evaporated and gasified;

[0009] The copper tube is arranged at the top position of the low-pressure section working area of ​​the shock tube. The top end of the copper tube is sealed, and the bottom end is connected to the inner side of the shock tube. The hardness of the copper tube is relatively small, and external force can be applied to the copper tube to cause the copper tube to deform.

[0010] The alkali metal glass bubble is arranged in the copper tube, and the alkali metal seed is arranged in the alkali metal glass bubble. The alkali metal glass bubble can be broken by applying an external force to the copper tube, so that the alkali metal seed falls into the shock tube.

[0011] The present application uses an internal mixing alkali metal seed injection system. The alkali metal seeds can be vaporized in the working area and directly mixed with the inert gas. The alkali metal seeds are placed in the alkali metal glass bulb, which can ensure that the total amount of alkali metal seeds remains unchanged during vaporization and mixing with the inert gas, thereby achieving accurate measurement of the alkali metal seeds. When in use, the inert gas can be filled into the low-pressure section of the shock tube and directly mixed with the vaporized alkali metal seeds in the low-pressure section working area, without the problem of alkali metal seed loss.

[0012] In an optional embodiment, the controllable temperature heater comprises:

[0013] A heating assembly, disposed on the outer side wall of the low-pressure section working area of ​​the shock tube, suitable for heating the shock tube;

[0014] The controller is connected to the heating component and is suitable for controlling the heating power of the heating component.

[0015] In an optional embodiment, the heating component is a heating belt, and the low-pressure section working area of ​​the shock tube is sleeved on the inner side of the heating belt. The heating belt is an annular belt that can heat the shock tube inside.

[0016] In an optional implementation, it also includes:

[0017] The seed filling device is fixedly connected to the shock tube, the bottom end of the seed filling device passes through the heating belt and is connected to the shock tube, and the top end of the seed filling device is fixedly connected to and connected to the copper tube. The seed filling device can play a role in connecting the copper tube and the shock tube.

[0018] In an optional embodiment, the copper tube is arranged vertically, so that the alkali metal seeds can enter the shock tube easily.

[0019] In an optional embodiment, the copper tube is composed of a storage section, a diameter-changing section, and a filling section from top to bottom, the diameter of the storage section is larger than the diameter of the filling section, and the alkali metal glass bubble is stuck in the storage section. The copper tube supports the alkali metal glass bubble inside, the diameter of the alkali metal glass bubble can be larger than the diameter of the filling section and smaller than the diameter of the storage section, and can be stuck in the storage section, and an external force is applied to the copper tube of the storage section to deform the storage section, so that the alkali metal glass bubble is broken, and the alkali metal seed enters the shock tube from the filling section.

[0020] In an optional embodiment, the temperature inside the low-pressure working area of ​​the shock tube is higher than the boiling point of the alkali metal seeds, so that the alkali metal seeds falling into the low-pressure working area of ​​the shock tube can be rapidly evaporated and gasified.

[0021] In an optional embodiment, there is a first distance between the copper tube and the shock tube, and the temperature at the copper tube is lower than the softening temperature of the copper tube, so as to prevent the copper tube from softening.

[0022] In an optional embodiment, there is a second distance between the alkali metal glass bubble and the shock tube, and the temperature in the alkali metal glass bubble is higher than the melting point of the alkali metal seed and lower than the boiling point of the alkali metal seed, so that the alkali metal seed in the alkali metal glass bubble is in liquid state, and the alkali metal seed can flow into the shock tube after the alkali metal glass bubble is broken.

[0023] In an optional embodiment, temperature sensors are respectively provided on the outer side walls at both ends of the low-pressure section of the shock tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 It is a schematic diagram of the structure of an embodiment of the present invention;

[0026] Figure 2 for Figure 1 A partial enlarged view of

[0027] Figure 3 It is a schematic diagram of the copper tube structure of the present invention.

[0028] Description of reference numerals:

[0029] 1. Shock tube; 2. Rubber sealing ring; 3. Seed filling device; 4. Alkali metal glass bulb; 5. Copper tube; 6. Heating belt; 7. Temperature sensor. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0031] Combine the following Figures 1 to 3 , describing an embodiment of the present invention.

[0032] According to an embodiment of the present invention, an alkali metal seed injection system for shock tube magnetohydrodynamic power generation is provided, which is used to inject alkali metal seeds into the low-pressure section working area of ​​the shock tube 1. It should be noted that the shock tube 1 is generally made of stainless steel or other metal materials, and has good thermal conductivity and heat dissipation properties, including:

[0033] A controllable temperature heater is arranged on the outer wall of the low-pressure section working area of ​​the shock tube 1, and can heat the low-pressure section working area of ​​the shock tube 1, so that the alkali metal seeds falling into the low-pressure section working area of ​​the shock tube 1 are quickly evaporated and gasified;

[0034] The copper tube 5 is arranged at the top position of the low-pressure section working area of ​​the shock tube 1. The top end of the copper tube 5 is sealed, and the bottom end is connected to the inner side of the shock tube 1. The hardness of the copper tube 5 is relatively small, and an external force can be applied to the copper tube 5 to cause the copper tube 5 to deform.

[0035] The alkali metal glass bubble 4 is arranged in the copper tube 5, and the alkali metal seed is arranged in the alkali metal glass bubble 4. Specifically, the alkali metal seed can be encapsulated in an ampoule. The alkali metal glass bubble 4 can be broken by applying an external force to the copper tube 5, so that the alkali metal seed falls into the shock tube 1.

[0036] The present application uses an internal mixing alkali metal seed injection system. The alkali metal seeds can be vaporized in the working area and directly mixed with the inert gas. The alkali metal seeds are arranged in the alkali metal glass bulb 4. The total amount of the alkali metal seeds can be kept constant during the vaporization and mixing with the inert gas, thereby achieving accurate measurement of the alkali metal seeds. When in use, the inert gas can be filled into the low-pressure section of the shock tube 1 and directly mixed with the vaporized alkali metal seeds in the low-pressure section working area, and there is no problem of alkali metal seed loss.

[0037] The present application can use metallic cesium as a seed and argon as a power generation medium, select a section of about 2.5m in the middle of the low-pressure section of the shock tube 1 as the filling section of the working area, and the controllable temperature heater can be set in the area of ​​about 0.3-0.5m in the middle of the filling section.

[0038] It should be noted that the low-pressure working area of ​​the shock tube 1 is separated from the driving gas section and the power generation channel section by a specific film. A hole can also be opened on the shock tube 1 in the low-pressure section. Before injecting the alkali metal seeds, a vacuum pump can be connected to the hole to extract the gas in the low-pressure shock tube 1, so that the low-pressure shock tube 1 has a certain vacuum degree to prevent the metal cesium from reacting with the gas in the shock tube 1. Then use the gas source, such as a high-pressure gas cylinder, to add argon working fluid to the low-pressure section of the shock tube 1 through the hole. A pressure sensor can be set in the low-pressure shock tube 1 to detect the gas pressure of the low-pressure section of the shock tube 1 when adding argon working fluid, so that the argon is filled to the design pressure. At this time, the quality of the argon working fluid inside the low-pressure section reaches the value required for power generation conditions.

[0039] In an optional embodiment, the controllable temperature heater comprises:

[0040] A heating assembly, arranged on the outer side wall of the low-pressure section working area of ​​the shock tube 1, suitable for heating the shock tube 1;

[0041] The controller is connected to the heating component and is suitable for controlling the heating power of the heating component.

[0042] In an optional embodiment, the heating component is a heating belt 6, and the low-pressure section working area of ​​the shock tube 1 is mounted on the inner side of the heating belt 6. The heating belt 6 is an annular belt that can be used to wrap the shock tube 1. The metal wall temperature of the specific design area in the middle of the low-pressure section can be quickly heated to a temperature higher than the vaporization temperature of the alkali metal seed under the corresponding working pressure. The controllable temperature heater is then switched to low-power operation, and the input heat power is balanced with the heat dissipation power of the metal wall of the low-pressure section. A designed temperature gradient is formed from the middle position to both sides of the low-pressure section, and a steady state can be maintained. The boiling point of metallic cesium is 669.3°C. The controller can control the heating belt 6 to heat the low-pressure section working area of ​​the shock tube 1, so that the wall temperature in the middle of the low-pressure section about 300mm quickly reaches above the boiling point.

[0043] Specifically, the temperature determination method can be to set a temperature sensor 7 in the low-pressure section to monitor the temperature of the middle 300mm area of ​​the low-pressure section. It can also be obtained through experience. For example, when the heating power of the heating belt 6 is set to a certain special value through the controller, the temperature of the middle 300mm area of ​​the low-pressure section will be higher than the boiling point of metallic cesium. In addition, the controllable temperature heater can be turned on to make the wall temperature of the middle 300mm area of ​​the low-pressure section quickly reach about 600-700°C, and then reduce the thermal power of the heating belt 6. Since the low-pressure section of the shock tube 1 is made of stainless steel or other metal materials, it has good thermal conductivity and heat dissipation properties. When the controllable temperature heater is set to a certain specific output power, the heat dissipation and heat input are balanced. At this time, it is ensured that the temperature of the middle area of ​​the low-pressure section is higher than the vaporization temperature of cesium, and due to the temperature gradient, it is ensured that the rubber sealing ring 2 of the flange of the shock tube 1 on both sides will not be damaged.

[0044] In an optional implementation, it also includes:

[0045] The seed filling device 3 is fixedly connected to the shock tube 1, the bottom end of the seed filling device 3 passes through the heating belt 6 and is connected to the shock tube 1, and the top end of the seed filling device 3 is fixedly connected and connected to the copper tube 5. The seed filling device 3 can connect the copper tube 5 and the shock tube 1. The seed filling device 3 can be a seed filling flange or a quantitative injection pump. When the seed filling device 3 is a seed filling flange, it can be welded to the opening of the shock tube 1.

[0046] It should be noted that two or more seed filling devices 3 can be designed as needed, and a corresponding number of copper tubes 5 can be installed, and they can be arranged one by one.

[0047] In an optional embodiment, the copper tube 5 is arranged vertically, so that the alkali metal seeds can enter the shock tube 1 conveniently.

[0048] In an optional embodiment, the copper tube 5 is composed of a storage section, a diameter-changing section, and a filling section from top to bottom. The diameter of the storage section is larger than the diameter of the filling section, and the alkali metal glass bubble 4 is stuck in the storage section. The copper tube 5 supports the alkali metal glass bubble 4 on the inside. The diameter of the alkali metal glass bubble 4 may be larger than the diameter of the filling section and smaller than the diameter of the storage section. It may be stuck in the storage section. External force is applied to the copper tube 5 of the storage section to deform the storage section, so that the alkali metal glass bubble 4 is broken, and the alkali metal seeds flow into the shock tube 1 from the filling section. The alkali metal glass bubble 4 may also be a structure with a narrow lower end and a wide upper end arranged in the copper tube 5. It should be noted that the copper tube 5 may also be a straight tube. The alkali metal glass bubble 4 is fixed on the inner wall of the copper tube 5. The alkali metal glass bubble 4 may be connected to the copper tube 5 by gluing, such as Figure 1 and Figure 2 shown.

[0049] It should be noted that pliers can be used to crush the cesium bubble encapsulating the alkali metal seed inside the copper tube 5 without destroying the seal thereof, so that the liquid metal cesium flows into the interior of the shock tube 1 along the seed filling device 3. When the metal cesium drips onto the high-temperature metal wall surface of the low-pressure section of the shock tube 1, it evaporates and gasifies rapidly, and at the same time quickly diffuses forward and backward of the shock tube 1, forming a good mixture with the working fluid argon gas.

[0050] In an optional embodiment, the temperature inside the low-pressure working area of ​​the shock tube 1 is higher than the boiling point of the alkali metal seeds, so that the alkali metal seeds falling into the low-pressure working area of ​​the shock tube 1 can be rapidly evaporated and gasified.

[0051] In an optional embodiment, there is a first distance between the copper tube 5 and the shock tube 1, and the temperature at the copper tube 5 is lower than the softening temperature of the copper tube 5. The copper tube 5 can be prevented from softening. The upper area of ​​the controllable temperature heater can heat the copper tube 5 due to heat conduction, heat radiation, etc. If the copper tube 5 softens, the copper tube 5 may lose its support for the alkali metal glass bubble 4, and the softened copper tube 5 is not conducive to the liquid alkali metal seeds flowing into the shock tube 1. It should be noted that the specific value of the first distance should be determined based on experiments and calculations, and is generally 20 cm to 30 cm.

[0052] In an optional embodiment, there is a second distance between the alkali metal glass bubble 4 and the shock tube 1, and the temperature in the alkali metal glass bubble 4 is higher than the melting point of the alkali metal seed and lower than the boiling point of the alkali metal seed. The alkali metal seed in the alkali metal glass bubble 4 can be liquid, and the alkali metal seed can flow into the shock tube 1 after the alkali metal glass bubble 4 is broken. It should be noted that the specific value of the second distance should be determined based on experiments and calculations, and is generally 30 cm to 40 cm.

[0053] In an optional embodiment, temperature sensors 7 are respectively provided on the outer walls at both ends of the low-pressure section of the shock tube 1. It should be noted that generally, shock tube 1 flanges are provided at both ends of the low-pressure section of the shock tube 1 for connecting with shock tubes 1 of other sections, and rubber sealing rings 2 are provided on the flanges of the shock tube 1. When the controllable temperature heater is set to a certain output power, the heat dissipation and heat input are balanced. At this time, it is necessary to ensure that the temperature in the middle area of ​​the low-pressure section is higher than the vaporization temperature of cesium, and due to the temperature gradient, it is necessary to ensure that the rubber sealing rings 2 of the flanges of the shock tubes 1 on both sides will not be damaged. The temperature of the outer wall at both ends of the low-pressure section of the shock tube 1 can be monitored by the temperature sensor 7 to prevent the rubber sealing ring 2 from overheating. When the temperature of the outer wall at both ends of the low-pressure section of the shock tube 1 is too high, the temperature at the rubber sealing ring 2 can be reduced by replacing a longer shock tube 1 or lengthening the shock tube 1 so that the rubber sealing ring 2 will not cause damage to the rubber sealing ring 2.

[0054] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. An alkali metal seed injection system for shock tube magnetohydrodynamic power generation, used for injecting alkali metal seeds into the low-pressure section working area of ​​the shock tube (1), characterized in that: include: A controllable temperature heater is arranged on the outer wall of the low-pressure section working area of ​​the shock tube (1); A copper tube (5) is arranged at the top of the low-pressure section working area of ​​the shock tube (1), the top of the copper tube (5) is sealed, and the bottom of the copper tube (5) is connected to the inner side of the shock tube (1); The alkali metal glass bubble (4) is arranged in the copper tube (5), and an alkali metal seed is arranged in the alkali metal glass bubble (4).

2. The alkali metal seed injection system for shock tube magnetohydrodynamic power generation according to claim 1, characterized in that: The controllable temperature heater comprises: A heating component, arranged on the outer wall of the low-pressure section working area of ​​the shock tube (1), suitable for heating the shock tube (1); The controller is connected to the heating component and is suitable for controlling the heating power of the heating component.

3. The alkali metal seed injection system for shock tube magnetohydrodynamic power generation according to claim 2, characterized in that: The heating component is a heating belt (6), and the low-pressure section working area of ​​the shock tube (1) is sleeved on the inner side of the heating belt (6).

4. The alkali metal seed injection system for shock tube magnetohydrodynamic power generation according to claim 3, characterized in that: Also includes: The seed filling device (3) is fixedly connected to the shock tube (1), the bottom end of the seed filling device (3) passes through the heating belt (6) and is connected to the shock tube (1), and the top end of the seed filling device (3) is fixedly connected to and connected to the copper tube (5).

5. The alkali metal seed injection system for shock tube magnetohydrodynamic power generation according to claim 1, characterized in that: The copper tube (5) is arranged vertically.

6. The alkali metal seed injection system for shock tube magnetohydrodynamic power generation according to claim 1, characterized in that: The copper tube (5) comprises a storage section, a diameter-changing section and a filling section from top to bottom, the diameter of the storage section is larger than the diameter of the filling section, and the alkali metal glass bulb (4) is clamped in the storage section.

7. The alkali metal seed injection system for shock tube magnetohydrodynamic power generation according to claim 1, characterized in that: The temperature inside the low-pressure section working area of ​​the shock tube (1) is higher than the boiling point of the alkali metal seed.

8. The alkali metal seed injection system for shock tube magnetohydrodynamic power generation according to claim 1, characterized in that: There is a first distance between the copper tube (5) and the shock tube (1), and the temperature at the copper tube (5) is lower than the softening temperature of the copper tube (5).

9. The alkali metal seed injection system for shock tube magnetohydrodynamic power generation according to claim 1, characterized in that: There is a second distance between the alkali metal glass bubble (4) and the shock tube (1), and the temperature inside the alkali metal glass bubble (4) is higher than the melting point of the alkali metal seed and lower than the boiling point of the alkali metal seed.

10. The alkali metal seed injection system for shock tube magnetohydrodynamic power generation according to claim 1, characterized in that: Temperature sensors (7) are respectively arranged on the outer side walls at both ends of the low-pressure section of the shock tube (1).

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