WO2013173952A1

WO2013173952A1 - Thermionic power supply

Info

Publication number: WO2013173952A1
Application number: PCT/CN2012/001295
Authority: WO
Inventors: 张维国
Original assignee: Zhang Weiguo
Priority date: 2012-05-22
Filing date: 2012-09-24
Publication date: 2013-11-28

Abstract

A thermionic power supply comprises an emitting electrode (1), a receiving electrode (2), a high-temperature heat chamber (4) and a high-temperature heat source (7). The emitting electrode is made of a thermionic emitting material having a melting point higher than the temperature of the high-temperature heat source. The receiving electrode is made of a non-thermionic emitting material having a melting point higher than the temperature of the high-temperature heat source. The materials of the emitting electrode and the receiving electrode satisfy a condition θ _E<θ _C or θ _E=θ _C, θ _E being the work function of the material of the emitting electrode, and θ _C being the work function of the material of the receiving electrode. The emitting electrode and the receiving electrode are arranged in the high-temperature heat chamber defined by a heat-insulating casing. A gap (3) between the emitting electrode and the receiving electrode is 0.1-2 mm. The emitting electrode and the receiving electrode are connected in series to a load and a direct current power supply through a lead A (9) and a lead B (10). Alternatively, the emitting electrode and the receiving electrode of the thermionic power supply may both be made of a thermionic emitting material having a melting point higher than the temperature of the high-temperature heat source, and the emitting electrode and the receiving electrode are connected in series to a load and an alternating current power supply through a lead A and a lead B. The thermionic power supply does not necessarily require a drop in the temperature of the receiving electrode, the heat loss is low, and the efficiency of thermoelectric conversion is high.

Description

Thermal ion power supply

The invention belongs to the technical field of thermal power generation, and relates to a static thermoelectric conversion device, in particular to a highly efficient thermal ion power source.

technical background

Although the history of large-scale use of electricity is only a hundred years, based on the thermal power conversion efficiency of about 4% to 35% of various power generation devices, there is no mature and efficient technology for large-scale acquisition of nuclear power and solar power, resulting in dozens of earth. The fossil energy accumulated in the past few hundred years has been rapidly decreasing. Faced with the depletion of fossil energy and the deteriorating natural environment, we urgently need to break through the constraints of heat engine efficiency, improve the level of power generation technology, and then use solar energy and nuclear energy resources on a large scale to reduce or even reduce Stop the consumption of disposable fossil energy, which is the mainstream and direction of energy saving and emission reduction in the world today.

The basic structure of the existing thermionic power supply is: emitter, receiver, high temperature heat source and cooling device, all of which are indispensable components of the thermionic power supply. The emitter is heated by a high temperature heat source, the receiver is cooled by a heat rejection device, and the emitter and receiver are filled with helium vapor. The working principle is as follows: The emitter is heated by a high-temperature heat source, and the hot electrons escape. The hot electrons pass through a very small gap filled with helium vapor, and are transferred to the receiving pole, and the receiving pole captures the hot electrons, so that between the emitter and the receiving pole. A potential energy difference is formed, and in the process, the receiving electrode cools and dissipates heat through the heat sink.

Its output voltage meets:

The potential energy difference between the interelectrode = the energy of the emitter material, the work energy of the receiver material, and the kinetic energy of the thermal electron transport loss: Ue = 0 _{E -} 0c - E _T where Z7 is the open circuit voltage and e is the electronic power. ^ is the work energy of the emitter material, ^ is the work function of the receiver material, and £ is the kinetic energy of the heat electron transport loss.

Thermionic power supply designed according to the above formula and principle: the work function of the emitter material can only be greater than the work function of the receiver material, ie & > , otherwise the output voltage is zero or even negative. Because the sink function of the receiving pole is low, the receiving pole obviously has better low-temperature hot electron emission characteristics than the emitter. In order to prevent the counter electrode from emitting the counter electron to the emitter, the receiving pole must actively cool down the heat. As a result, a large amount of heat energy is lost and cannot be converted into electric energy, and the actual thermoelectric conversion efficiency is less than ιο%. Because of its small power generation capacity, low output voltage, complex power supply structure and operating conditions, and high cost, there are still many problems that hinder commercial applications. This type of power supply has not been promoted for many years. Summary of the invention

1

Confirmation In order to solve the above technical problems, the present invention is based on a new theoretical study, and proposes a new thermionic power source, which has a simple structure and operating conditions, and its thermoelectric conversion efficiency is significantly higher than that of the existing thermionic power source.

The technical solution of the present invention includes two, one of which is: a thermionic power source, including an emitter, a receiver, a high temperature heat chamber and a high temperature heat source, and the emitter is made of a thermal electron emission material having a melting point higher than a temperature of a high temperature heat source, the receiving pole It is made of a non-thermal electron-emitting material having a melting point higher than that of a high-temperature heat source. The emitter electrode and the receiving material used satisfies the condition: <or 0 _E = 0c; emitter and receiver electrodes are disposed on the high-temperature heat insulating chamber formed in the housing, the gap between the emitter electrode and the receiving electrode is 0.5 ~ 2 The emitter and the receiver are connected in series with the wire A and the wire B and the DC power supply of the pump valve, wherein the emitter is connected to the negative pole of the DC power supply of the pump valve, and the receiving pole is connected to the positive pole of the DC power supply of the pump valve.

The receiving pole does not include a cooling device.

The high-temperature heat source is disposed in the high-temperature heat chamber for simultaneously heating the emitter and the receiver in the high-temperature heat chamber, and the heating temperature of the high-temperature heat source is 600K~3300K.

The working principle is as follows: The high temperature heat source heats the emitter to cause it to emit hot electrons, and the pump valve DC power source can make the potential of the receiving pole higher than the emitter through the loop, providing additional power for the movement of the hot electrons to the receiving pole. The hot electrons fly to the receiving pole due to the presence of the initial kinetic energy and are driven by the driving potential. The thermal electrons are trapped on the receiving pole through the interelectrode gap. Due to the large work function, the receiving electrode has low emission electron efficiency, a small amount of hot electrons, or because of the electric field hindrance of the pump valve DC power supply, it cannot balance with the amount of hot electrons from the emitter, and the thermal electrons tend to The receiving poles are concentrated and the interelectrode voltage is formed. The interelectrode gap can be internally filled with metal vapor as needed to assist in conducting the hot electrons and increasing the flow guiding coefficient. The working condition of the power supply is conducive to heat preservation and simple structure. There is no need to deliberately set the temperature difference between the emitter and the receiving pole. The receiving pole has no necessary heat dissipation system due to the thermoelectric conversion principle, the system heat loss is small, and the thermoelectric conversion efficiency is high.

The second is: thermionic power source, including the emitter, the receiver, the high temperature hot chamber and the heat source, and the emitter and the receiver are made of a thermal electron emission material having a melting point higher than the temperature of the high temperature heat source, and the receiving pole is not included. The cooling device; the material used for the emitter and the receiver meets the conditions: 0 ₁ ; < or 2 0 ^ The emitter and the receiver are both disposed in the high temperature thermal cavity formed by the heat insulating casing, and the interelectrode gap between the emitter and the receiver 0. 1~2 mm; The emitter and receiver are connected in series by wire Α and wire B and the AC power of the pump valve.

The high-temperature heat source is disposed in the high-temperature heat chamber for heating the emitter and the receiver in the high-temperature heat chamber, and the heating temperature of the high-temperature heat source is 600K~3300K.

The working principle is as follows: The high temperature heat source simultaneously heats the emitter and the receiver, causing the hot electrons to escape from both the emitter and the receiver, and the AC voltage of the pump valve sends an AC induced voltage, so that the two electrodes are the emitter and the receiver, and Alternating polarity, the two electrodes accelerate the escape of hot electrons or exacerbate the trapping of hot electrons under the action of the alternating electric field of the pump valve AC power source, and then form Transaction variable current.

The 1⁄2 is the work function of the emitter material, and the & is the work function of the receiving material.

The above-mentioned thermionic power source, compared with the existing thermionic power source, the receiving end of the thermionic power source of the present invention can be disposed in the high temperature thermal chamber together with the emitter, and can operate under the same or similar temperature conditions. The heating temperature of the high temperature heat source is 600K~3300K. It may not include a heat sink for receiving the extreme cooling and heat removal.

The above technical solutions are based on the new thermoelectric conversion theory as follows:

After the hot electrons escape from the high-temperature emitter, the initial total energy relative to the emitter is +, where ^^ is the kinetic energy of the hot electrons, so that £■» is the maximum kinetic energy of the hot electrons at a certain hot temperature, then there is „ £ 0, kinetic energy is the condition that thermal electrons overcome the interelectrode voltage and the distance between the poles. We call it the thermal electron leaping energy. The formula shows that S, the emitter escape function is the lower limit of the energy of the hot electron, we put ^^ =0Thermal electrons that do not have a flying energy are called critical hot electrons. Only when the distance between the poles is sufficiently small, once they escape, they are in the center of the pole spacing, and can be equipotentially received and emitter. Probably directly captured, we call this small enough inter-electrode distance to be the ideal pole spacing. Any hot electrons that have not been externally operated in the loop return to the emitter and their energy relative to the emitter remains Ε, and ideal. The open-pitch voltage of the pole-separated Ion source depends on the value of the last trapped hot electron, which should be the maximum energy that the emitter can reach at a certain temperature. Value +, that is the formula:

U e = emitter material work + maximum kinetic energy after hot electrons escape

= 0 _E + B ; Equation 1

In the case where the interelectrode distance is greater than the ideal pole spacing, the thermal electrons with lower critical hot electrons and lower leap energy cannot overcome the voltage jump pole spacing between the poles. Only the hot electrons with higher leap energy can reach the receiving pole. The voltage appears as a variable related to the distance between the poles; when the receiver is at the position where the emitter's hot electrons are at the initial kinetic energy value, Ε is called the interpole hop energy, and the last heat that reaches the receiver and is captured. The initial kinetic energy of the electron is the maximum value, and this initial kinetic energy includes the leap energy of the overcoming pole voltage and the interpole flying energy reaching the receiving pole, ie „= t/ _e + £ , so the open circuit voltage t of the thermionic power source satisfies the formula:

U e = maximum jump of thermal electrons

= Ε, — Ef type 2

Wherein, Equation 1 is the first voltage formula for thermionic power generation, and Equation 2 is the second voltage formula for thermionic power generation.

The hot electrons in the loop overcome the surface barrier from the hot metal surface is the only thermoelectric conversion link, but the hot electrons that can only stay in the pole or return to the emitter do not contribute to the loop, the inventors call it invalid hot electrons; The electron can only accumulate voltage or push the loop current to work externally when it is captured by the receiving pole. This kind of emitter can be captured by the receiving pole. Hot electron inventors call it effective hot electrons.

The thermionic thermoelectric conversion theory of the present invention shows that the open circuit voltage of the thermionic power source is closely related to the energy of the emitter material, the temperature of the emitter, the distance between the electrodes, and the like, and is independent of the material of the receiving electrode; The voltage calculation formula is completely different from the calculation formula of the interelectrode voltage of the existing thermionic power source. The above-mentioned thermionic power generation voltage formula (Formula 1 and Formula 2) determines that the thermionic power source of the present invention is completely different from the electrode material of the existing thermionic power source, that is, in order to ensure that the emitter emits hot electrons larger than the receiving pole. The work function of the emitter material is required to be less than or equal to the work function of the receiving material, the receiving electrode does not need to cool down and heat, and the two electrodes can work simultaneously under the same or similar high temperature environment.

The details are as follows: The emitter 1 is made of a thermal electron-emitting material having a melting point higher than the temperature of the high-temperature heat source 7, and the receiving electrode 2 is made of a non-thermal electron-emitting material having a melting point higher than that of the high-temperature heat source 7, at 0 _c >0 _E W Next, simultaneously heating the two electrodes in the adiabatic high temperature thermal cavity, the thermal electron emission scale of the emitter is greater than or equal to the receiving pole, in order to generate more effective hot electrons and increase the utilization rate of the hot electrons, in addition to being able to In addition to filling the metal vapor, it is also possible to form a DC-type thermionic power source in series with an external pump-valve DC power supply in the circuit.

Both the emitter 1 and the receiver 2 are made of a thermal electron-emitting material having a melting point higher than the temperature of the high-temperature heat source 7, and in the case of 0 _c >0 _e or & = ^, the two electrodes in the adiabatic high-temperature heat chamber are Simultaneous heating, large-scale thermal electron emission can occur in both electrodes. In order to generate more effective hot electrons and increase the utilization rate of hot electrons, in addition to filling the metal vapor between the poles, an external pump can be connected in series in the loop. The valve AC power source constitutes an AC type thermionic power source.

In the case where ^ is significantly greater than &, the thermal electron emission current of the emitter is much larger than the thermal electron emission current of the receiving electrode under the same or similar high temperature conditions, and the two electrodes can be placed together in the adiabatic high temperature thermal cavity. , Thermoelectric conversion can be achieved without the need for heat removal. At this time, the output voltage of the pump valve DC power supply or the pump valve AC power supply described in the technical solution is both. Volt.

The external power supply connected in series in the technical solution can provide a driving electric field from the receiving pole to the emitter, and an electric pump function for increasing the thermal electron leaping energy and increasing the number of effective hot electrons, and at the same time, it can also suppress the receiving. The polar emitter emits the electrical extension of the hot electrons, so it is called the pump valve power supply.

Because the electrodes of the same material have good power generation characteristics, when the pump power supply is set to the AC output, the two electrodes are alternately converted into the emitter and the receiver, thus forming an AC-type thermionic power source. The thermal electrons are oscillated between the poles, reducing the distance between the poles that the hot electrons need to cross, improving the flow conductivity coefficient, reducing the space charge effect between the poles, facilitating the heat and temperature balance of the two plates, facilitating the power transmission and Regulation.

The pump valve power supply is an accelerating pump and a rectifying valve for the flow of hot electrons, which provides a shield voltage of S^/e volts for the hot electrons from the receiver in the loop to prevent it from leaping towards the emitter, while it gives the hot electrons from the emitter Also provides an extra leap to £ P, so that the total energy of the hot electron changes to E=0 _E + E _t + E _P , that is, the voltage value of /e is added to the loop, so the total voltage of the loop is equal to the voltage of the hot ion power supply superimposed pump valve, and the pump power is hot. The acceleration energy of the electrons will be released in the external circuit and can be fed back to the pump valve power supply.

The beneficial effects of the invention are -

1. The temperature drop of the receiving end of the thermionic power source of the present invention is an unnecessary condition, the heat energy loss is small, the thermoelectric conversion efficiency is high, and the thermoelectric conversion efficiency of the existing thermionic power source is less than 10%, and the thermoelectric power source of the present invention is thermoelectric. The theoretical limit of conversion efficiency can reach more than 90%, and the practical efficiency can reach more than 50%;

2. The receiving pole of the present invention creates favorable conditions for overcoming the space charge effect, avoiding high-temperature bombardment of the receiving electrode, and increasing the thermal electron current density in the state of hot electrons escaping;

3. The novel thermionic power source of the invention can rectify the hot electron flow between the poles by means of the pump valve power source, and increase the current density, and can directly output AC or DC current, and has a wide application range;

4. It can use nuclear fuel, solar heat collection, firepower and other heat sources to generate electricity;

5. It can generate electricity independently or use the existing power system as the pump and valve power to jointly generate electricity;

6. Its isothermal electrode working environment and insulated outer casing structure make the power supply structure simple and reliable, which is conducive to equipment manufacturing and nuclear power safety.

DRAWINGS

1 is a schematic structural view of a conventional thermionic power source or Embodiment 1 or Embodiment 2;

2 is a schematic structural view of a direct current type thermionic power source according to the present invention;

Fig. 3 is a schematic view showing the structure of an alternating current type thermionic power source of the present invention.

In the figure, 1, emitter, 2, receiving pole, 3, interelectrode gap, 4, high temperature hot chamber, 5, load, 6, insulated housing, 7, high temperature heat source, 8, cooling device, 9, wire A, 10 , wire B, 11, pump valve DC power supply, 12, pump wide AC power.

Specific implementation method

The invention will be specifically described below based on the drawings and examples.

Example 1

As shown in FIG. 1, the present invention includes an emitter 1, a receiver 2, a high temperature heat chamber 4, and a high temperature heat source 7, a high temperature heat source 7 disposed on one side of the emitter 1, and a temperature lowering device 8 disposed on the side of the receiver 2. The emitter 1 is made of carbonized W-Th0 ₂ material, the receiving pole 2 is made of W metal material, and the work function of emitter 1 and receiver 2 is satisfied: 0 _E <0 _C , emitter 1 and receiver 2 The inter-electrode gap 3 of the emitter 1 and the receiving pole 2 is 0.1. Millimeter, vacuum between the poles. The emitter 1 and the receiving pole 2 are connected in series with the wire A9 and the wire B10 by a load 5 and a pump DC power supply 11 , the emitter 1 is connected to the negative electrode of the pump valve DC power source 11 , and the receiving pole 2 is connected to the positive electrode of the pump valve DC power source 11 . The pump valve DC power supply 11 voltage is 0 volts. The high-temperature heat source 7 is used to heat the emitter 1, and the receiver 2 is cooled by the temperature-lowering device 8. The temperature of the emitter 1 is 900-1500K, and the temperature of the receiver 2 is 600-1499K.

The calculation shows that the actual thermoelectric conversion efficiency is 20%.

Example 2

As shown in Fig. 1, the same as in the first embodiment except for the following differences.

The interelectrode gap 3 between the emitter 1 and the receiving pole 2 is 0.2 mm, and the interpole is filled with steam.

The calculation shows that the actual thermoelectric conversion efficiency is 22%.

Example 3

As shown in Fig. 2, the same as in the first embodiment except for the following differences.

A high-temperature heat source is provided on the emitter 1 side, and the temperature-receiving device 8 is not provided on the receiver pole 2. The inter-electrode gap 3 between the emitter 1 and the receiving pole 2 is 0.2 mm, and the inter-electrode is filled with steam. Pump valve DC power supply 11 voltage is 0-220 volts. The high temperature heat source 7 is used to heat the emitter 1 and the receiver 2, the temperature of the emitter 1 is 900-1500K, and the temperature of the receiving pole 2 is 900_1500 Κ.

The calculation shows that the actual thermoelectric conversion efficiency is 60%.

Example 4

As shown in Fig. 2, the same as in the third embodiment except for the following differences.

5毫米。 The emitter 1 is made of a carbonized W-Th0 ₂ material, the receiving end 2 is made of C material, the inter-electrode gap 3 between the emitter 1 and the receiving pole 2 is 0. 5 mm.

The calculation shows that the actual thermoelectric conversion efficiency is 48%.

Example 5

As shown in FIG. 3, the present invention includes an emitter 1, a receiver 2, a high temperature thermal chamber 4, and a high temperature heat source 7. Both the emitter 1 and the receiver 2 are provided with a high temperature heat source 7 for heating. Both the emitter 1 and the receiver 2 are made of carbonized W-Th0 ₂ material, and the work function of the emitter 1 is equal to the work function of the receiver 2, that is, 0 _E =0 _C ; both the emitter 1 and the receiver 2 are set. 1毫米之间真空真空真空。 In the high temperature thermal chamber 4 formed by the heat insulating housing 6, the interelectrode gap 3 between the emitter 1 and the receiving pole 2 is 0.1 mm, and the pole is evacuated. The emitter 1 and the receiver 2 are connected in series with the conductor A9 and the conductor B10 by a load 5 and a pump valve AC power source 12. The pump valve AC power supply 12 voltage is 0-220 volts. The high temperature heat source 7 simultaneously heats the emitter 1 and the receiver 2, the temperature of the emitter 1 is 900-1500K, and the temperature of the receiver 2 is 900-1500K.

The calculation shows that the actual thermoelectric conversion efficiency is 62%. Example 6

As shown in Fig. 3, the same as Embodiment 5 except for the following differences.

The emitter 1 and the pole of the receiver 2 are filled with steam.

The calculation shows that the actual thermoelectric conversion efficiency is 58%.

Example 7

The calculation shows that the actual thermoelectric conversion efficiency is 561.

Example 8

The interelectrode gap 3 between the emitter 1 and the receiving pole 2 is 0.5 mm, and the interpole is filled with steam.

The calculation shows that the actual thermoelectric conversion efficiency is 52%.

Example 9

The interelectrode gap 3 between the emitter 1 and the receiving pole 2 is 1.0 mm, and the interpole is filled with steam.

The calculation shows that the actual thermoelectric conversion efficiency is 46%.

Example 10

The interelectrode gap 3 between the emitter 1 and the receiving pole 2 is 1. 5 mm, and the interpole is filled with steam.

The calculation shows that the actual thermoelectric conversion efficiency is 40%.

Example 11

The interelectrode gap 3 between the emitter 1 and the receiving pole 2 is 2.0 mm, and the poles are filled with steam.

The calculation shows that the actual thermoelectric conversion efficiency is 36%.

According to the above embodiment, it can be known that the thermionic power source provided by the present invention greatly improves the thermoelectric conversion efficiency. Moreover, the above embodiment is tested by using a small-scale micro device, and in practical applications, the thermoelectric conversion efficiency is higher as the device scale increases.

Claims

1. A thermionic power source comprising an emitter (1), a receiver (2), a high temperature heat chamber (4) and a high temperature heat source (7), characterized in that the emitter (1) has a melting point higher than a high temperature heat source ( 7) The temperature is made of a thermal electron-emitting material, and the receiving electrode (2) is made of a non-thermal electron-emitting material having a melting point higher than a temperature of the high-temperature heat source (7);

The materials used for the emitter (1) and the receiver (2) satisfy the condition: 0 _Ε < or 0 _E = =0 _C;

The emitter (1) and the receiving pole (2) are both disposed in the high temperature thermal chamber (4) formed by the heat insulating casing (6), and the emitter

(1) The interelectrode gap (3) with the receiving pole (2) is 0. 1-2 mm;

The emitter (1) and the receiving pole (2) are connected in series by a wire A (9) and a wire B (10) (5) and a pump DC power supply

(II), wherein the emitter (1) is connected to the negative pole of the pump valve DC power supply (11), and the receiving pole (2) is connected to the positive pole of the pump valve DC power supply (11).

2. The thermionic power source according to claim 1, characterized in that the receiving pole (2) does not comprise a cooling device (8).

3. The thermionic power source according to claim 1 or 2, wherein the high temperature heat source (7) is disposed in the high temperature heat chamber (4) for simultaneously heating the emitter in the high temperature heat chamber (4) (1) and the receiving pole (2), the heating temperature of the high temperature heat source (7) is 600K to 3300K.

4. A thermionic power source comprising an emitter (1), a receiver (2), a high temperature heat chamber (4) and a high temperature heat source (7), characterized in that both the emitter (1) and the receiver (2) It is made of a thermal electron emission material having a melting point higher than the temperature of the high temperature heat source (7), and the receiving pole (2) does not include a cooling device (8);

The materials used for the emitter (1) and the receiver (2) satisfy the condition: < or 0 _E =0 _C:

(1) The interelectrode gap (3) with the receiving pole (2) is 0.1 to 2 mm;

The emitter (1) and the receiving pole (2) are connected in series (5) and the pump AC power supply through the wire A (9) and the wire B (10).

(12).

The thermionic power source according to claim 4, wherein the high temperature heat source (7) is disposed in the high temperature heat chamber (4) for heating the emitter in the high temperature heat chamber (4) (1) And the receiving pole (2), the heating temperature of the high temperature heat source (7) is 600K~3300K.