Magnetohydrodynamic power generation device

Abstract

The invention discloses a magnetohydrodynamic power generation device, and relates to the technical field of nuclear reactors, the magnetohydrodynamic power generation device comprises a protective shell, a power generation channel penetrates through the interior of the protective shell in the axial direction, and an electrified coil is arranged on the outer side of the protective shell and used for providing a magnetic field; the air pump communicates with the power generation channel through a pipeline, the pipeline is filled with Ar gas, and the air pump is used for pressurizing the Ar gas; the reactor core is arranged in the power generation channel in the axial direction, the reactor core is formed by building a plurality of fuel plates in a # shape, and fuel in the fuel plates generates a plurality of fission fragments after nuclear fission; the thickness of the fuel plate is smaller than the range of fission fragments; and the reflecting layer is arranged on the outer wall of the reactor core in a sleeving manner and comprises two semicircular metal electrodes which are symmetrically arranged. According to the invention, fission fragments generated by a nuclear reactor are utilized to bombard rare gas to ionize the gas, and the ionized gas generates power through the magnetohydrodynamic generator, so that relatively high thermoelectric conversion efficiency is ensured, and the defects of harsh working conditions and large potential safety hazards existing in an existing method are avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of nuclear reactors, and in particular to a magnetohydrodynamic power generation device. Background Art

[0002] In the traditional water-cooled reactor power generation mode, its thermal hydraulic requirements are often more stringent, and the thermal hydraulic calculations often involve multiphase flow, which has problems such as high calculation difficulty, high engineering cost, and great safety hazards. The traditional thermoelectric conversion method also greatly limits the design and operation of the reactor. As a new technology in development, magnetohydrodynamic power generation has high thermoelectric conversion efficiency and fewer thermal conditions, but the preparation of fuel gas and fuel quality of traditional magnetohydrodynamic generators is complex and difficult to calculate. The combination of nuclear reactors and magnetohydrodynamic power generation was proposed as a new idea. In the 1960s, the academic community proposed a gas-cooled nuclear reactor system with a nuclear reactor in series with a magnetohydrodynamic generator.

[0003] At present, the research progress of this space power system combining reactor with magnetohydrodynamic power generation has been considerable. For example, the United States has conducted a lot of research on magnetohydrodynamic generators based on gaseous uranium fuel. Holman et al. proposed a conceptual design scheme based on the NERVA reactor as a prototype, helium as a working fluid, and combined with magnetohydrodynamic power generation technology. On this basis, Litchford et al. evaluated the performance of the nuclear magnetohydrodynamic power generation system at 100MWth thermal power, but due to the safety of gaseous uranium fuel and the feasibility of structural materials, it is difficult to put it into actual engineering. Domestic research is mostly aimed at the Brayton cycle system.

[0004] Therefore, existing research still uses the reactor as a heat source to heat the gas and create a high-temperature environment to ionize the gas into plasma. The ionization efficiency is low and harsh thermal conditions cannot be avoided. Summary of the invention

[0005] The present invention provides a magnetohydrodynamic power generation device, which solves the problem that the existing research still uses the reactor as a heat source to heat the gas, creates a high-temperature environment to ionize the gas into plasma, has low ionization efficiency and cannot avoid harsh thermal conditions.

[0006] The present invention provides a magnetohydrodynamic power generation device, comprising:

[0007] A protective shell has a power generation channel running through it in the axial direction and a power-carrying coil arranged on its outer side for providing a magnetic field;

[0008] An air pump is connected to the power generation channel through a pipeline, the interior of the pipeline is filled with Ar gas, and the air pump is used to pressurize the Ar gas;

[0009] A core is axially arranged inside the power generation channel, wherein the core is formed by a plurality of fuel plates arranged in a tic-tac-toe pattern, wherein the fuel in the fuel plates generates a plurality of fission fragments after nuclear fission occurs; and the thickness of the fuel plates is smaller than the range of the fission fragments;

[0010] A reflective layer, sleeved on the outer wall of the core, comprising two symmetrically arranged semi-annular metal electrodes;

[0011] The Ar gas is pressurized to a set speed by an air pump and enters the power generation channel. Multiple fission fragments bombard the Ar gas and cause collision ionization. The Ar gas is ionized into plasma, which moves in a magnetic field environment and generates electricity through electromagnetic induction.

[0012] Preferably, the fuel in the fuel plate is uranium dioxide UO2, the core is 6 m long, 2 m wide, and 2 m high, the fuel plate is 5 μm thick, and the gap between the fuel plates is 0.14 mm.

[0013] Preferably, the two metal electrodes are connected to an external load as positive and negative electrodes.

[0014] Preferably, the two metal electrodes are separated by beryllium oxide (BeO).

[0015] Preferably, the air pump inlet is communicated with the channel outlet of the power generation channel, and the air pump outlet is communicated with the channel inlet of the power generation channel.

[0016] Preferably, the material of the metal electrode is metal beryllium Be.

[0017] Preferably, a steam generator is also included, which is arranged between the channel outlet of the power generation channel and the air pump inlet, and is used to cool the plasma. The cooled plasma is accelerated by the air pump to enter the core for collision ionization again, and the next power generation cycle is carried out.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The present invention proposes a magnetohydrodynamic power generation device, which adopts a working mode combining a core and a power generation channel. The core is formed by a plurality of fuel plates built in a tic-tac-toe shape, and the thickness of the fuel plates is less than the range of the fission fragments. After the fuel undergoes nuclear fission to produce fission fragments with extremely high energy, since the thickness of the fuel plates is less than or close to the range of the fission fragments, the fission fragments will not be completely deposited in the fuel plates, and the emitted fission fragments directly bombard the Ar gas to ionize the gas into plasma. When the plasma passes through the magnetohydrodynamic generator channel, it generates electricity through the principle of electromagnetic induction under the action of an external magnetic field. The present invention uses the fission fragments generated by the core fuel to bombard the rare gas to ionize the gas, and the ionized gas generates electricity through the magnetohydrodynamic generator, while ensuring a high thermoelectric conversion efficiency, avoiding the shortcomings of the existing methods such as harsh working conditions and great safety hazards. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 A structural diagram of a magnetohydrodynamic power generation device of the present invention;

[0022] Figure 2 It is the reaction process principle diagram of the present invention;

[0023] Figure 3 This is a core structure diagram of the present invention;

[0024] Figure 4 This is a core design diagram with a reflective layer of the present invention;

[0025] Figure 5 Graphs 1 and 2 show the power and efficiency of the system at different gas initial velocities according to the embodiment of the present invention.

[0026] In the figure: 1-channel outlet, 2-external load, 3-metal electrode, 4-core, 5-channel inlet, 6-powered coil, 7-steam generator, 8-air pump, 9-BeO. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only 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 ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] The present invention proposes a magnetohydrodynamic power generation device, which adopts a working mode combining a core structure with a channel of the magnetohydrodynamic power generation device, that is, the fission fragments generated by the core fuel are used to bombard the rare gas to ionize the rare gas, and the ionized gas is used to generate electricity through the magnetohydrodynamic generator. While ensuring a high power generation efficiency, it avoids the disadvantages of the traditional water-cooled reactor power generation mode, such as harsh working conditions and great safety hazards. Figure 1 A magnetohydrodynamic power generation device of the present invention includes a protective shell, an air pump 8, a core 4 and a reflective layer.

[0029] A power generation channel is axially penetrated inside the protective shell, and a power-carrying coil 6 is arranged on the outside of the protective shell. The power-carrying coil 6 is used to provide a magnetic field.

[0030] When the core is running at low power, the air pump 8 is connected to the power generation channel through the pipeline to form a cycle. The interior of the pipeline is filled with argon Ar gas, and the air pump 8 is used to pressurize the Ar gas. Before working, the Ar gas is filled in the pipeline, and the Ar gas enters the power generation channel through the channel inlet 5 after being pressurized and pushed by the air pump 8 to obtain a certain speed.

[0031] In this embodiment, Ar gas needs to be filled into the entire circulation system in advance. Under the action of the air pump 8, the Ar gas at the left core is high pressure, and the right core is low pressure to drive the gas movement. The specific amount of Ar gas needs to be determined based on the channel volume, pipeline volume and air pump power of the actual system. The basic principle is to allow the Ar gas to fill the entire circulation system and to be able to generate a high pressure that meets the requirements (about 20MPa) under the push of the air pump.

[0032] The core 4 is arranged inside the power generation channel along the axial direction. The core 4 is an ultra-thin tic-tac-toe grid structure of the micron level. The core 4 is formed by a plurality of fuel plates in a tic-tac-toe shape. The fuel of the core 4 is used to generate nuclear fission and produce a plurality of fission fragments. The fuel is UO2, which is evenly distributed in the fuel plate, and the thickness of the fuel plate is less than the range of the fission fragments.

[0033] Nuclear fission occurs in the fuel of core 4 to produce a large number of high-energy fission fragments. The range of these fission fragments in the core is about 10μm. Since the thickness of the fuel plate of core 4 is also in the micron range and is smaller than the range of the fission fragments, the fission fragments will not be completely deposited in the fuel plate. After depositing part of the energy in the fuel plate, the fission fragments are ejected from the fuel plate into the gap of the fuel plate with energy of tens of mega-electron volts. The gap is filled with high-pressure Ar gas, and the ejected fission fragments directly bombard the Ar gas atoms, and the two collide and ionize. When the ionization degree is high enough, the Ar gas is ionized into plasma. The free electrons and gas molecules in the plasma are in a non-equilibrium state, and the electron temperature is much higher than the temperature of the neutral atoms in the gas. That is, most of the energy of the fission fragments is given to the electrons, and the ionization efficiency is high. At the same time, since the neutral atoms, which account for a large proportion of the number, have a low temperature, the plasma temperature will not be too high. The entire reaction process is like this: Figure 2 As shown, the plasma re-circulates from the channel outlet 1.

[0034] In this embodiment, the basic requirements for the core are a fuel plate thickness of less than 10 μm and sufficient gas gaps. The optimization results require a core plate thickness of about 5 μm, an Ar gas pressure of about 20 MPa in the gas pipeline, and a maximum core gap spacing of 0.14 mm. The core design diagram is shown in Figure 3 shown.

[0035] The parameter design of the spacing between the fuel plates is based on the thickness of the fuel plates and the gas pressure. Calculations show that at a gas pressure of 15Mpa to 20Mpa, a core gap spacing of about 0.1mm can meet the ionization requirements. At the same time, as the gas flow rate is faster, the gas receives fission fragment ionization in the fuel plate gap for a shorter time, and its conductivity should decrease with the gas flow rate. However, since the conductivity is of a high order of magnitude, it will hardly change in magnitude at low flow rates, so it is believed that the conductivity will remain almost unchanged at low gas flow rates. At a core reaction power of 3MW, it can be calculated that the average electron temperature is 4×10 6 K, the electron number density is 7.7×10 19 , this result is applied to the power calculation of the Hall generator channel, and it is found that when the gas flow rate is 10m / s and the pressure is 20Mpa, the power generation is about 0.47MW and the efficiency is about 15.6%. The specific results are shown in Table 1 and Figure 5 The calculation results preliminarily prove that the scheme is feasible. This power generation method avoids the shortcomings of the traditional water-cooled reactor power generation mode, such as harsh working conditions and great safety hazards, while ensuring high power generation efficiency.

[0036] Table 1 Power and efficiency of the system at different initial speeds

[0037]

[0038] The calculation method of impact ionization first calculates the mass and energy distribution of fission fragments to obtain the fission fragment energy spectrum, while considering the energy deposition in the fuel plate and the energy consumed by the impact ionization. By calculating the range and energy loss of the fission fragments in the fuel plate and Ar gas, the maximum ionization degree of Ar gas and the maximum power density of the core are used as optimization targets, the thickness and spacing of the UO2 fuel are determined, and the core fuel is modeled. The impact ionization process is a multi-body interaction process between fission fragments, Ar gas atoms, and electrons. Under the condition of a two-body collision approximation in the local area, the average kinetic energy obtained by a single impact ionization electron is about 0.2% of the energy of the incident fission fragment, and then the electron temperature, electron number density, and gas conductivity can be obtained. Finally, the total power and efficiency of the entire system are calculated based on the design model of the Hall generator channel.

[0039] Reference Figure 4 The reflective layer is set outside the core 4, including two symmetrically arranged semi-circular metal electrodes 3, which are connected to the external load as positive and negative electrodes. The two metal electrodes 3 are separated by BeO9. When the reactor is running, some neutrons will always escape outside the core. In order to reduce the loss of these neutrons, a layer of material is placed outside the core to form a reflective layer to reflect back the neutrons that escape from the core.

[0040] In this embodiment, the metal electrode 3 is metal Be, which serves as a reflective layer and a metal electrode at the same time. The positive and negative plates are separated by BeO. Under the external magnetic field 6, the moving plasma generates electricity due to electromagnetic induction.

[0041] Refer again Figure 1 The present invention further includes a steam generator 7. The steam generator 7 is arranged between the channel outlet 1 and the inlet of the gas pump 8, and is used for performing the Rankine cycle. When the core is running at high power, the plasma with residual heat leaves the channel outlet 1 and undergoes the Rankine cycle. After cooling, the ionization degree decreases, resulting in a decrease in gas conductivity. Gas with too low conductivity is not enough to generate a large enough power generation, so it is accelerated by the gas pump 8 to enter the core 4 for collision ionization again, and the ionization degree is increased again for the next cycle.

[0042] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0043] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A magnetohydrodynamic power generation device, characterized in that: include: A protective shell, wherein a power generation channel is axially penetrated inside the shell, and a power supply coil (6) is arranged on the outside of the shell, and the power supply coil (6) is used to provide a magnetic field; An air pump (8) is connected to the power generation channel through a pipeline, the interior of the pipeline is filled with Ar gas, and the air pump (8) is used to pressurize the Ar gas; A core (4) is axially arranged inside the power generation channel, the core (4) being formed by a plurality of fuel plates arranged in a tic-tac-toe pattern, wherein the fuel in the fuel plates generates a plurality of fission fragments after nuclear fission occurs; the thickness of the fuel plates being smaller than the range of the fission fragments; A reflective layer, which is sleeved on the outer wall of the core (4), and comprises two symmetrically arranged semi-annular metal electrodes (3); The Ar gas is pressurized to a set speed by an air pump (8) and enters a power generation channel. A plurality of fission fragments bombard the Ar gas and cause collision ionization. The Ar gas is ionized into plasma. The plasma moves in a magnetic field environment and generates electricity through electromagnetic induction.

2. A magnetohydrodynamic power generation device as claimed in claim 1, characterized in that: The fuel in the fuel plate is uranium dioxide UO2, the core (4) is 6m long, 2m wide and 2m high, the thickness of the fuel plate is 5μm, and the gap between the fuel plates is 0.14mm.

3. A magnetohydrodynamic power generation device as claimed in claim 1, characterized in that: The two metal electrodes (3) are connected to an external load (2) as positive and negative electrodes.

4. A magnetohydrodynamic power generation device as claimed in claim 1, characterized in that: The two metal electrodes (3) are separated by beryllium oxide BeO (9).

5. A magnetohydrodynamic power generation device as claimed in claim 1, characterized in that: The inlet of the air pump (8) is connected to the channel outlet (1) of the power generation channel, and the outlet is connected to the channel inlet (5) of the power generation channel.

6. A magnetohydrodynamic power generation device as claimed in claim 1, characterized in that: The material of the metal electrode is metal beryllium Be.

7. A magnetohydrodynamic power generation device as claimed in claim 5, characterized in that: It also includes a steam generator (7), which is arranged between the channel outlet (1) of the power generation channel and the inlet of the gas pump (8) and is used to cool the plasma. The cooled plasma is accelerated by the gas pump (8) to enter the core (4) to undergo collision ionization again, and then the next power generation cycle is carried out.

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