Liquid-gas phase change device excited by arc discharge and its excitation method

Abstract

The present invention discloses a liquid-gas phase change device based on arc discharge excitation and an excitation method thereof. The liquid-gas phase change device includes a primary chamber and a plurality of phase change units arranged on the primary chamber and communicated with the primary chamber; each phase change unit includes a high-voltage power generation module, a first discharge electrode, a second discharge electrode and a heating tooling. The second ends of the first discharge electrode and the second discharge electrode respectively insert into the cavity of the heating tooling from two opposite connection ports of the heating tooling and are aligned; the first ends of the first discharge electrode and the second discharge electrode are respectively connected to the positive output end and the negative output end of the high-voltage power generation module. The present invention can realize the rapid heating of the liquid medium, significantly improve the heating efficiency and the gaseous phase change reaction rate, and further improve the energy conversion efficiency.

Description

Technical Field

[0001] The present invention belongs to the technical field of liquid-gas phase change, and particularly relates to a liquid-gas phase change device based on arc discharge excitation and an excitation method thereof. Background Art

[0002] When discussing phase change expansion technology, it is necessary to emphasize the importance of heating a substance in a closed system. The heating rate not only directly affects the speed of the work process, but also the heat transfer efficiency is a key factor determining the energy conversion efficiency.

[0003] Currently, the heating methods for phase change medium expansion mainly include combustion heat release by chemical heating and resistance wire heating by electric heating. Combustion heat release heating, as a chemical process, has unstable heat transfer characteristics, is difficult to precisely control, and is prone to generating harmful gases during the combustion of chemical substances, resulting in its large environmental pollution and low safety. In contrast, resistance wire heating, as an electric heating method, although the heat transfer process is relatively stable and easy to control, its thermal efficiency is not high, and the heating rate is relatively slow. Usually, a resistance wire heating device needs to be preheated before use, which takes a long time and consumes a lot of energy.

[0004] With the increasingly wide application of phase change medium expansion technology in various fields, its technical maturity is also continuously improving. The heating process, as the core link of this technology, requires careful design and optimization to meet the requirements of high efficiency, high speed, process stability, and high safety. This not only involves the selection of heating methods, but also includes the precise control of heating rate and heat transfer efficiency to ensure the efficiency of the energy conversion process and the sustainability of the environment. Therefore, future research and development should focus on the heat transfer speed during the phase change process to meet these growing technical needs. Summary of the Invention

[0005] The purpose of the present invention is to provide a liquid-gas phase change device based on arc discharge excitation and an excitation method thereof, which can ensure the stability and controllability of heating while achieving a fast heating rate and high efficiency during the heating process.

[0006] The present invention solves the above technical problems through the following technical solutions: A liquid-gas phase change device based on arc discharge excitation includes a primary chamber, and a plurality of phase change units provided on the primary chamber and communicating with the primary chamber;

[0007] Each of the phase change units includes a high-voltage power generation module, a first discharge electrode, a second discharge electrode, and a heating tooling. The second ends of the first discharge electrode and the second discharge electrode respectively insert into the cavity of the heating tooling from two opposite connection ports of the heating tooling and are aligned; the first ends of the first discharge electrode and the second discharge electrode are respectively connected to the positive output terminal and the negative output terminal of the high-voltage power generation module;

[0008] The high-voltage power generation module is used to generate DC high-voltage electricity; the first discharge electrode and the second discharge electrode are used to transmit the DC high-voltage electricity generated by the high-voltage power generation module into the cavity of the heating tooling; the heating tooling is used to inject a liquid medium and provide a place for the liquid medium to undergo gaseous phase change and expansion under the action of the DC high-voltage electricity; the initial volume chamber is used to receive the high-pressure gaseous medium released by the expansion and output it after equalizing and reducing the pressure of the high-pressure gas medium.

[0009] Further, the high-voltage power generation module includes a self-excited oscillation circuit, a transformer, and a voltage multiplier rectification circuit connected in sequence. The input end of the self-excited oscillation circuit is connected to an external power supply. The positive output end and the negative output end of the voltage multiplier rectification circuit are respectively connected to the first end of the first discharge electrode and the first end of the second discharge electrode.

[0010] The self-excited oscillation circuit is used to generate high-frequency alternating current; the transformer is used to generate an induced voltage under the action of the high-frequency alternating current; the voltage multiplier rectification circuit is used to multiply and rectify the induced voltage to output DC high-voltage electricity.

[0011] Further, the self-excited oscillation circuit includes a capacitor C1, a capacitor C2, a resistor R1, a resistor R2, a triode V1, and a triode V2. The base of the triode V2 is connected to the first end of the resistor R2 and the positive pole of the capacitor C2. The collector of the triode V2 is connected to the second end of the resistor R2, the base and the emitter of the triode V1. The collector of the triode V1 and the negative pole of the capacitor C2 are respectively connected to the primary coil of the transformer. The two ends of the resistor R1 are respectively connected to the second end of the resistor R2 and the positive pole of the capacitor C1. The negative pole of the capacitor C1 and the emitter of the triode V2 are grounded.

[0012] Further, the high-voltage power generation module includes a high-voltage power supply, a charging switch, a pulse capacitor, a discharge switch, and a control module; the high-voltage power supply, the pulse capacitor, and the charging switch are connected in sequence to form a charging circuit; one end of the discharge switch is connected to the positive pole of the pulse capacitor, and the other end is connected to the first end of the first discharge electrode. The first end of the second discharge electrode is connected to the negative pole of the pulse capacitor; the control module is used to control the conduction and cut-off of the charging switch and the discharge switch.

[0013] Further, the heating tooling includes a pressure tube, a rupture disk, and a pressure ring; a pressure relief port is provided at the bottom of the pressure tube, the rupture disk is arranged in the pressure relief port and fixed by the pressure ring; a plurality of connection ports are provided on the side of the pressure tube.

[0014] Further, the heating tooling further includes a transparent pressing cover and an observation window; an observation port is provided at the top of the pressure tube, the transparent pressing cover is fixedly arranged at the top of the pressure tube through a connecting bolt, the observation window is arranged between the transparent pressing cover and the pressure tube and aligned with the observation port; a first buffer pad is arranged between the transparent pressing cover and the observation window, a second buffer pad is arranged between the observation window and the pressure tube, and a plurality of sealing members are sleeved between the observation window and the pressure tube.

[0015] Further, both the first discharge electrode and the second discharge electrode include an electrode, a second sealing ring, a third sealing ring and a housing. The housing is sleeved on the electrode, the second sealing ring is sleeved on the first end of the electrode, the third sealing ring is sleeved on the second end of the electrode, and the sealing connection between the electrode and the heating tooling is realized through the second sealing ring and the third sealing ring.

[0016] Further, the distance between the second ends of the first discharge electrode and the second discharge electrode is determined according to the breakdown voltage of the medium to be phase-changed. The specific determination formula is:

[0017] ; ;

[0018] Wherein, represents the breakdown voltage of the medium, , represent the constants in the Paschen's law of the medium, represents the initial pressure of the medium, represents the distance between the second ends of the first discharge electrode and the second discharge electrode, represents an intermediate quantity, represents the secondary electron emission coefficient.

[0019] Based on the same concept, the present invention further provides an excitation method for a liquid-gas phase change device, which is applied to the liquid-gas phase change device based on arc discharge excitation as described above. The excitation method includes:

[0020] The DC high voltage generated by the high voltage generation module is transmitted to the cavity of the heating tooling through the first discharge electrode and the second discharge electrode, and the liquid medium in the cavity of the heating tooling is ionized and broken down to generate a high voltage arc;

[0021] When the energy provided by the high voltage arc is equal to the energy required for the gaseous phase change of the medium, the liquid medium is excited to undergo a gaseous phase change, and the pressure in the cavity of the heating tooling gradually increases;

[0022] When the pressure in the cavity of the heating tooling reaches the pressure relief threshold and the rupture disc at the pressure relief port of the heating tooling ruptures, the high pressure gaseous medium is released through the pressure relief port and enters the initial volume chamber;

[0023] The high-pressure gaseous medium is output after equalizing and decompressing in the initial volume chamber.

[0024] Furthermore, the calculation formula for the energy required for the phase change of the medium in the gaseous state is:

[0025] ;

[0026] where, represents the energy required for the phase change of the medium in the gaseous state, represents the heat transfer efficiency of the high-voltage arc, represents the voltage applied across the first discharge electrode and the second discharge electrode, represents the high-voltage arc current, represents the discharge time of the high-voltage power generation module, represents the density of the medium, represents the volume of the medium, represents the latent heat of phase change of the medium.

[0027] Compared with the prior art, the advantages of the present invention are as follows:

[0028] The liquid-gas phase change device of the present invention realizes the heating of the liquid medium based on the principle of high-voltage arc discharge. High-voltage arc discharge heating does not require preheating, and the high-voltage arc has high energy, which can realize the rapid heating of the liquid medium, significantly improve the heating efficiency and the rate of gaseous phase change reaction, and further improve the energy conversion efficiency.

[0029] The liquid-gas phase change device of the present invention does not rely on special processing equipment or processes, ensuring its economy and safety during application; at the same time, no harmful gases are generated during the entire phase change process, showing significant advantages in terms of environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the present invention, the drawings required for the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only one embodiment of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0031] Figure 1 is a three-dimensional view of the liquid-gas phase change device in the embodiment of the present invention;

[0032] Figure 2 is a top view of the liquid-gas phase change device in the embodiment of the present invention;

[0033] Figure 3 is a bottom view of the liquid-gas phase change device in the embodiment of the present invention;

[0034] Figure 4It is a side view of the liquid-gas phase change device in the embodiment of the present invention;

[0035] Figure 5 It is a schematic diagram of the first implementation manner of the high-voltage power generation module in the embodiment of the present invention; where, R represents a resistor, C represents a capacitor, D represents a diode, V represents a triode, and T represents a transformer;

[0036] Figure 6 It is a schematic diagram of the second implementation manner of the high-voltage power generation module in the embodiment of the present invention;

[0037] Figure 7 It is a schematic diagram of the first drive circuit or the second drive circuit in the embodiment of the present invention;

[0038] Figure 8 It is a schematic diagram of the control circuit in the embodiment of the present invention;

[0039] Figure 9 It is a schematic diagram of the high-voltage power supply in the embodiment of the present invention;

[0040] Figure 10 It is a three-dimensional view of the first discharge electrode, the second discharge electrode, and the heating tooling in the embodiment of the present invention;

[0041] Figure 11 It is a cross-sectional view of the first discharge electrode, the second discharge electrode, and the heating tooling in the embodiment of the present invention;

[0042] Figure 12 It is a three-dimensional view of the heating tooling in the embodiment of the present invention;

[0043] Figure 13 It is an exploded view of the heating tooling in the embodiment of the present invention;

[0044] Figure 14 It is a three-dimensional view of the first discharge electrode or the second discharge electrode in the embodiment of the present invention;

[0045] Figure 15 It is an exploded view of the first discharge electrode or the second discharge electrode in the embodiment of the present invention.

[0046] Explanation of reference numerals: 1-phase change unit, 11-heating tooling, 111-pressure pipe, 112-pressure ring, 113-bursting disc, 114-transparent pressure cover, 115-observation window, 1151-first buffer pad, 1152-second buffer pad, 1153-first sealing ring, 1154-first sealing ring, 1155-second sealing ring, 116-connecting bolt, 12-first discharge electrode, 121-electrode, 122-second sealing ring, 123-third sealing ring, 124-housing, 13-second discharge electrode, 2-initial volume chamber. Detailed implementation manners

[0047] Combined with the accompanying drawings in the embodiments of the present invention, the technical solutions in the present invention are clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0048] The technical solutions of the present application will be described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments.

[0049] Embodiment 1

[0050] As Figures 1 to 4 , the liquid-gas phase change device based on arc discharge excitation provided in the embodiment of the present invention includes an initial volume chamber 2 and a plurality of phase change units 1 provided on and communicating with the initial volume chamber 2; each phase change unit 1 is used to excite the liquid medium therein to undergo a gas phase change and expansion through arc discharge, and then release the high-pressure gas medium to the initial volume chamber 2; the initial volume chamber 2 equalizes and reduces the pressure of the high-pressure gas medium and then outputs it to do external work. The initial volume chamber 2 is made of a pressure-resistant material.

[0051] The energy released by each phase change unit 1 is less, and the use environment has certain limitations. By arranging a plurality of phase change units 1 on the initial volume chamber 2 for energy storage and sequential release, the energy required for external work is satisfied. In this embodiment, the number of phase change units 1 is 4, and the medium is carbon dioxide, which can better meet the conditions required for phase change expansion.

[0052] As Figure 10 and Figure 11 shown, each phase change unit 1 includes a high-voltage power generation module, a first discharge electrode 12, a second discharge electrode 13, and a heating tooling 11. The second ends of the first discharge electrode 12 and the second discharge electrode 13 are respectively inserted into the cavity of the heating tooling 11 from two opposite connection ports of the heating tooling 11 and aligned; the first ends of the first discharge electrode 12 and the second discharge electrode 13 are respectively connected to the positive output terminal and the negative output terminal of the high-voltage power generation module.

[0053] Inject a liquid medium into the cavity of the heating tooling 11 through the connection port on the heating tooling 11. Supply electrical energy to the high-voltage electricity generation module through an external DC power supply. The DC high-voltage electricity generated by the high-voltage electricity generation module is transmitted to the cavity of the heating tooling 11 through the first discharge electrode 12 and the second discharge electrode 13. Ionize and break down the liquid medium in the cavity of the heating tooling 11 through the DC high-voltage electricity to generate a high-voltage arc. The high-voltage arc has higher energy and a temperature as high as thousands of degrees. In the cavity of the heating tooling 11, the high-voltage arc provides phase change energy for the liquid medium through heat conduction and heat radiation effects, realizing the conversion of electrical energy into phase change energy. When the energy provided by the high-voltage arc is sufficient to cause the liquid medium to undergo a gaseous phase change, the liquid medium begins to undergo a gaseous phase change and expand, and the pressure in the cavity of the heating tooling 11 continuously increases. When the pressure in the cavity reaches the pressure relief threshold, the rupture disk 113 at the pressure relief port of the heating tooling 11 ruptures, and the gaseous medium is released and enters the primary volume chamber 2, and the pressure in the cavity is released, realizing the final conversion of energy into mechanical energy.

[0054] The arc can be regarded as a heat source with a small size but stable heat transfer ability. The strategy for optimizing the arc heat transfer efficiency involves two core elements: First, enhance its heat transfer rate by increasing the temperature of the arc; Second, adjust the size of the arc to expand its heat transfer area. According to the arc formation theory, the length that the arc can generate is related to the voltage. The greater the voltage, the larger the arc that can be pulled. In the present invention, high-voltage electricity is generated by the high-voltage electricity generation module to form an arc, increasing the length of the arc and expanding the heat transfer area of the arc, thereby improving the heating efficiency.

[0055] The high-voltage electricity generation module is essentially an energy transmission device that converts the electrical energy input by the power supply into high-voltage electricity output. The dielectric constant of the liquid medium is relatively low and requires high-voltage electricity to be broken down, and then a high-voltage arc can be generated in the liquid medium. There are two implementation modes for the high-voltage electricity generation module of the present invention. In the first implementation mode of the high-voltage electricity generation module, as Figure 5 shown, the high-voltage electricity generation module includes a self-excited oscillation circuit, a transformer T1, and a voltage multiplier rectification circuit connected in sequence. The input end of the self-excited oscillation circuit is connected to an external power supply. The positive output end and the negative output end of the voltage multiplier rectification circuit are respectively connected to the first end of the first discharge electrode 12 and the first end of the second discharge electrode 13. The self-excited oscillation circuit is used to generate high-frequency alternating current; the transformer T1 is used to generate an induced voltage under the action of the high-frequency alternating current; the voltage multiplier rectification circuit is used to multiply and rectify the induced voltage generated by the transformer T1 and output DC high-voltage electricity.

[0056] In a specific embodiment of the present invention, the self-oscillation circuit includes a capacitor C1, a capacitor C2, a resistor R1, a resistor R2, a triode V1, and a triode V2. The base of the triode V2 is connected to the first end of the resistor R2 and the positive electrode of the capacitor C2. The collector of the triode V2 is connected to the second end of the resistor R2, the base and the emitter of the triode V1. The collector of the triode V1 and the negative electrode of the capacitor C2 are respectively connected to the primary coil of the transformer T1. The two ends of the resistor R1 are respectively connected to the second end of the resistor R2 and the positive electrode of the capacitor C1. The negative electrode of the capacitor C1 and the emitter of the triode V2 are grounded.

[0057] The transformer T1 includes a primary coil, a magnetic core, and a secondary coil. The input end of the self-oscillation circuit is connected to an external DC power supply. The self-oscillation circuit generates high-frequency alternating current to generate an induced voltage on the secondary coil of the transformer T1. The operation of the self-oscillation circuit is divided into a self-starting link and a positive feedback link. Self-starting link: After the external DC power supply is connected, it first acts on the base of the triode V2. At this time, a current is generated at the base of the triode V2, making the collector and emitter of the triode V2 conduct. The collector of the triode V2 is connected to the base of the triode V1. A current is generated at the collector of the triode V2, so a current is also introduced into the base of the triode V1, thereby making the collector and emitter of the triode V1 conduct and form a loop with the primary coil of the transformer T1 to generate a current. The magnitude of the current is affected by the opening degree of the triode V1. At this time, self-starting is satisfied.

[0058] To achieve the condition of self-excited oscillation, the positive feedback loop is essential. Positive feedback loop: The current direction generated by the primary coil of transformer T1 is from top to bottom. An induced electromotive force that impedes the increase in current will be generated on the primary coil, thereby generating an induced voltage. The direction of the induced voltage is opposite to the direction of the increasing current, that is, positive at the top and negative at the bottom. The primary coil of transformer T1 is connected to capacitor C2, causing the induced voltage to be applied to the circuit of capacitor C2. Under the action of capacitor C2, the positive voltage is applied to the base of transistor V2, and the negative voltage is applied to the emitter of transistor V2, resulting in an increase in the current on the base of transistor V2, causing an increase in the collector current of transistor V2, which in turn causes an increase in the base current of transistor V1, resulting in an increase in the collector current of transistor V1. The collector of transistor V1 is connected to the primary coil of transformer T1, causing the primary coil current to increase, forming positive feedback. Under the action of the feedback loop where capacitor C2 is located, the conduction capabilities of transistors V1 and V2 will quickly reach saturation. When the conduction capability of transistor V1 reaches the saturation state, the current in the primary coil of transformer T1 and the collector of transistor V1 will no longer be able to increase. At this time, the positive feedback disappears, resulting in no change trend in the current on the primary coil of transformer T1, and then the induced voltage immediately disappears. The base of transistor V2 loses the feedback voltage, causing the base current of transistor V2 to decrease, the collector current of transistor V2 to decrease, the base current of transistor V1 to decrease, and the collector current of transistor V1 to decrease. This causes the primary coil current of transformer T1 to decrease, thus generating an induced voltage that is negative at the top and positive at the bottom. At this time, a positive feedback opposite to the self-starting link is formed. As the current continues to decrease, the reverse induced voltage on the primary coil of transformer T1 continues to increase, causing the reverse voltage on the base of transistor V2 to continue to increase, which in turn causes the current to continue to decrease until transistors V1 and V2 reach the cut-off state and no longer conduct, and the primary coil current of transformer T1 drops to 0, completing one oscillation.

[0059] After the self-starting link and the positive feedback link, the self-excited oscillation circuit can continuously generate high-frequency alternating current. During the oscillation process, the direction of the induced voltage on the primary coil of transformer T1 continuously changes, generating a changing electric field, and the changing electric field generates a changing magnetic field in the magnetic core of transformer T1, causing the secondary coil of transformer T1 to induce a pulsating voltage. The magnitude of the pulsating voltage is determined by the ratio of the primary coil to the secondary coil of transformer T1. The number of turns of the secondary coil of transformer T1 is several times higher than that of the primary coil. The purpose is to multiply and amplify the voltage value of the secondary coil, thus completing the operation of the self-excited oscillation circuit.

[0060] The voltage doubler rectifier circuit filters and amplifies the changing voltage on the secondary coil of transformer T1 and forms a DC high voltage. Under the action of the self-excited oscillation circuit, an induced voltage with a continuously changing direction is generated on the secondary coil of transformer T1, such asFigure 5 As shown, the main circuit elements of the voltage multiplier rectifier circuit are capacitors and diodes. Assuming that the induced voltage on the secondary coil of transformer T1 is positive at the bottom and negative at the top, then under the action of diode D1, the induced voltage will first charge capacitor C3 until the voltage of capacitor C3 is equal to the induced voltage. Subsequently, the direction of the induced voltage changes to positive at the top and negative at the bottom. At this time, under the influence of diode D2, the induced voltage and capacitor C4 form a loop to charge capacitor C4, and the charging voltage is the sum of the voltage of capacitor C3 and the induced voltage, that is, twice the induced voltage; and so on, that is, each group of capacitors and diodes can boost the voltage. For Figure 5 the voltage multiplier rectifier circuit shown, the voltage value loaded on capacitor C9 is 7 times the induced voltage. And during the entire charging process, due to the influence of the diode, the direction of the charging voltage of the last capacitor C9 is fixed, that is, the direction of the charging voltage of capacitor C9 is positive on the right and negative on the left, realizing the process of rectifying alternating current into direct current. The release of the voltage on capacitor C9 is the DC high voltage.

[0061] The high-voltage generation module completes the work of doubling the input voltage twice and outputting it directly. The first doubling is under the action of transformer T1, and the second doubling is under the action of the voltage multiplier rectifier circuit. The multiple of the first doubling is determined by the turns ratio of the primary coil and the secondary coil of transformer T1. The ratio of the input voltage of the self-excited oscillation circuit to the induced voltage generated by transformer T1 is equal to the turns ratio of the primary coil and the secondary coil of transformer T1. Exemplarily, if the turns ratio of the primary coil and the secondary coil of transformer T1 is 1:100 and the input voltage of the self-excited oscillation circuit is 220V, then the induced voltage generated by transformer T1 is 22000V. Under Figure 5 the action of the voltage multiplier rectifier circuit shown, the finally output DC high voltage is 154000V.

[0062] In the second implementation manner of the high-voltage generation module, as Figure 6As shown in the figure, the high-voltage power generation module includes a high-voltage power supply U21, a charging switch U30, a pulse capacitor C109, a discharge switch, and a control module; the high-voltage power supply U21, the pulse capacitor C109, and the charging switch U30 are connected in sequence to form a charging circuit; one end of the discharge switch is connected to the positive electrode of the pulse capacitor C109, and the other end is connected to the first end of the first discharge electrode 12. The first end of the second discharge electrode 13 is connected to the negative electrode of the pulse capacitor C109; the control module is used to control the conduction and cut-off of the charging switch U30 and the discharge switch. In this embodiment, a diode D29 is also connected in series between the high-voltage power supply U21 and the pulse capacitor C109. The diode D29 can prevent the discharge current from flowing to the high-voltage power supply U21. The pulse capacitor C109 has the advantages of large capacitance and fast response, and can achieve the purpose of rapid charging and outputting DC high-voltage electricity, improving the heating speed of the liquid medium and the gas-phase phase change reaction rate.

[0063] When the charging switch U30 is turned on, the high-voltage power supply U21 charges the pulse capacitor C109. After the pulse capacitor C109 is fully charged, the charging switch U30 is turned off, the discharge switch is closed, and the pulse capacitor C109 outputs DC high-voltage electricity to the first discharge electrode 12 and the second discharge electrode 13, realizing the phase change excitation of the liquid medium in the cavity of the heating tooling 11.

[0064] In a specific embodiment of the present invention, the control module includes a control circuit, a first drive circuit, and a second drive circuit. The control circuit controls the conduction and cut-off of the charging switch U30 through the first drive circuit, and the control circuit controls the conduction and cut-off of the discharge switch through the second drive circuit. As Figure 7 shown, both the first drive circuit and the second drive circuit include a driver U31 and its peripheral circuit. The model of the driver U31 in this embodiment is the UCC27524 series. As Figure 8 shown, the control circuit includes a controller U9 and its peripheral circuit. The controller U9 in this embodiment uses a microcontroller with the model of ATMEGA88P.

[0065] Two output pins of the controller U9 are respectively connected to the input pin INA of the driver U31 in the first drive circuit and the second drive circuit. The output pins OUTA of the drivers U31 in the first drive circuit and the second drive circuit are respectively connected to the control terminals of the charging switch U30 and the discharge switch. As Figure 6 shown, the charging switch U30 uses a silicon carbide MOSFET module with the model of FF2600UXTR33T2M1, and its control terminal is the gate of the silicon carbide MOSFET module; the discharge switch uses three parallel MOS transistors, and its control terminal is the gate of each MOS transistor. Parallel shunt is carried out through three parallel MOS transistors Q30 / Q31 / Q, avoiding damage to the MOS transistor caused by overcurrent.

[0066] In a specific embodiment of the present invention, as Figure 9 shown, the high-voltage power supply U21 uses a step-down switching regulator U14 of model JW5357 to step down the voltage and output to charge the pulse capacitor C109. At the same time, the high-voltage power supply U21 also supplies power to the first drive circuit, the second drive circuit, and the control circuit.

[0067] In a specific embodiment of the present invention, as Figures 10 to 13 shown, the heating tooling 11 is a place where the liquid medium is heated, the phase change is excited, and expansion occurs. The heating tooling 11 includes a pressure tube 111, a rupture disk 113, and a compression ring 112; a pressure relief port is provided at the bottom of the pressure tube 111, the rupture disk 113 is arranged in the pressure relief port and fixed by the compression ring 112; a plurality of connection ports are provided on the side of the pressure tube 111, and two opposite connection ports are used to connect the first discharge electrode 12 and the second discharge electrode 13. The first discharge electrode 12 and the second discharge electrode 13 are threadedly and sealedly connected to the corresponding connection ports; other different connection ports are used to install a liquid injection valve for injecting the liquid medium, install a pressure sensor, etc. When there is no transparent pressure cover 114 at the top of the pressure tube 111, the top of the pressure tube 111 is a closed surface, and the changes in the cavity of the pressure tube 111 cannot be observed. The entire heating tooling 11 is a sealed structure, which avoids the leakage of the liquid medium and affects the phase change efficiency and external work. The pressure tube 111 of this embodiment is made of high-strength metal and has the characteristics of high temperature resistance and high pressure resistance.

[0068] In a specific embodiment of the present invention, as Figures 10 to 13 shown, the heating tooling 11 further includes a transparent pressure cover 114 and an observation window 115; an observation port is provided at the top of the pressure tube 111, the transparent pressure cover 114 is fixedly arranged at the top of the pressure tube 111 through a connection bolt 116, and the observation window 115 is arranged between the transparent pressure cover 114 and the pressure tube 111 and aligned with the observation port; a first buffer pad 1151 is provided between the transparent pressure cover 114 and the observation window 115, a second buffer pad 1152 is provided between the observation window 115 and the pressure tube 111, and a plurality of sealing members are sleeved between the observation window 115 and the pressure tube 111.

[0069] In this embodiment, a first sealing ring 1153, a first sealing ring 1154, and a second sealing ring 1155 are sequentially provided between the observation window 115 and the pressure tube 111. The first sealing ring 1153, the first sealing ring 1154, and the second sealing ring 1155 play a sealing role, ensuring the smooth progress of the phase change process. The first buffer pad 1151 and the second buffer pad 1152 can reduce the continuously increasing pressure on the observation window 115 during the phase change of the medium, protecting the observation window 115. The observation window 115 of this embodiment is made of quartz glass and can observe the arc ignition situation in the pressure tube 111. The connecting bolt 116 fixes the transparent gland 114 on the pressure tube 111 and fixes the first buffer pad 1151, the observation window 115, multiple sealing members, and the second buffer pad 1152.

[0070] The pressing ring 112 is used to connect and seal-fix the rupture disk 113 to the pressure tube 111. The maximum pressure that the rupture disk 113 can withstand is equal to the pressure relief threshold. When the pressure in the pressure tube 111 exceeds the pressure relief threshold, the rupture disk 113 ruptures, the pressure relief port opens, and the gaseous medium is released through the pressure relief port and enters the initial volume chamber 2.

[0071] The first discharge electrode 12 and the second discharge electrode 13 are high-voltage electric release devices. In the specific implementation manner of the present invention, as Figure 14 and Figure 15 shown, both the first discharge electrode 12 and the second discharge electrode 13 include an electrode 121, a second sealing ring 122, a third sealing ring 123, and a housing 124. The housing 124 is sleeved on the electrode 121, the second sealing ring 122 is sleeved on the first end of the electrode 121, and the third sealing ring 123 is sleeved on the second end of the electrode 121. The second sealing ring 122 and the third sealing ring 123 ensure the sealed connection between the electrode 121 and the heating tooling 11. The housing 124 is made of an insulating material to prevent the occurrence of a short circuit during discharge and ensure the concentration of energy during the release of the high-voltage arc; the electrode 121 is a high-voltage electric direct release component and is made of a conductive and high-temperature resistant material, such as graphite.

[0072] To ensure that the medium can be ionized and broken down to generate an arc, it is necessary to determine the distance between the second end of the first discharge electrode and the second end of the second discharge electrode. The distance between the second end of the first discharge electrode and the second end of the second discharge electrode is determined according to the breakdown voltage of the medium to be phase-changed. The specific determination formula is:

[0073] (1);

[0074] (2);

[0075] Among them, represents the breakdown voltage of the medium; 、 Denotes the constant in the Paschen's law for the medium, obtained by querying = 15 cm −1 Torr −1 , = 365 Vcm −1 Torr −1 ; Denotes the initial pressure of the medium. In this embodiment, the standard atmospheric pressure is taken; Denotes the distance between the second end of the first discharge electrode and the second end of the second discharge electrode; Denotes an intermediate quantity; Denotes the secondary electron emission coefficient. For carbon dioxide, the secondary electron emission coefficient is usually low, taking 10 -4 .

[0076] In this embodiment, the distance between the second end of the first discharge electrode and the second end of the second discharge electrode Is designed to be 2 cm. Substituting the distance Into formula (1), the breakdown voltage of carbon dioxide can be obtained to be approximately 77700 V. The DC high voltage output by the high voltage generation module is greater than the breakdown voltage of carbon dioxide, and carbon dioxide can be broken down to generate a high voltage arc.

[0077] Exemplarily, injecting 20 ml of carbon dioxide into each pressure tube requires providing about 1.4 kJ of heat to reach the pressure relief threshold of 30 Mpa. The temperature of the arc is very high, usually reaching above 6000 k. The present invention estimates the heating time based on the law of conservation of energy. Assuming no energy loss throughout the process and all the input electrical energy is released in the form of heat, with a heat transfer coefficient of 0.45 and an input current magnitude of 15 A, considering the arc as an ideal heat source, then the thermal efficiency is 1800 W, and the heating time can be calculated to be about 1.7 s. It can be seen that the time for exciting carbon dioxide by arc discharge is very short.

[0078] The liquid-gas phase change device of the present invention ensures fast heating rate, high efficiency, as well as stability, controllability, safety and pollution-free during the heating process.

[0079] Embodiment 2

[0080] The present invention embodiment also provides an excitation method for the liquid-gas phase change device in Embodiment 1, including the following steps:

[0081] Step S1: Inject a liquid medium into it through the connection port of the pressure tube;

[0082] Step S2: After the high-voltage power generation module is powered on, it generates direct current high voltage. The direct current high voltage is transmitted to the pressure tube through the first discharge electrode and the second discharge electrode, and the liquid medium in the pressure tube is ionized and broken down to generate a high-voltage arc.

[0083] Step S3: When the energy provided by the high-voltage arc is equal to the energy required for the gaseous phase change of the medium, the gaseous phase change of the liquid medium is excited, and the pressure in the pressure tube gradually increases.

[0084] Step S4: When the pressure in the pressure tube reaches the pressure relief threshold and the rupture disc in the pressure relief port at the bottom of the pressure tube ruptures, the high-pressure gaseous medium is released through the pressure relief port and enters the initial volume chamber.

[0085] Step S5: The high-pressure gaseous medium is output after equalizing pressure and reducing pressure in the initial volume chamber to achieve external work.

[0086] The formation of the high-voltage arc is related to the voltage applied to the first discharge electrode and the second discharge electrode and the distance between the second ends of the first discharge electrode and the second discharge electrode. According to the electric field strength calculation formula:

[0087] (3);

[0088] Among them, represents the electric field strength between the first discharge electrode and the second discharge electrode, represents the voltage applied to the first discharge electrode and the second discharge electrode, represents the distance between the second ends of the first discharge electrode and the second discharge electrode.

[0089] Increasing the voltage or decreasing the distance can increase the electric field strength , and the generation of the arc is essentially the directional movement of free electrons, that is, the emission of free electrons in the electrode. When the force on the free electrons due to the charge is greater than its binding force the free electrons are emitted from one end of the electrode to the other electrode to form an arc. According to the arc thermal effect and the theoretical formula of the phase change heat of substances, the relationship between the phase change heat of the medium and the required voltage and current can be derived. The derivation process is as follows:

[0090] The arc heating power is proportional to the square of the current applied to the electrodes at both ends of the arc:

[0091] (4);

[0092] Among them, represents the arc heating power, represents the arc current, represents the resistance value of the arc.

[0093] The resistance value of the electric arc will change with the change of the arc current and is proportional to the reciprocal of the square of the arc current. When considering the value of the heat generated by the electric arc, it can be directly considered that the heat generated by the electric arc is positively correlated with the arc current.

[0094] Formula for the energy required for the phase change of the medium:

[0095] (5);

[0096] wherein, represents the energy required for the gaseous phase change of the medium, represents the mass of the medium, represents the heat of phase change of the medium.

[0097] It can be seen from the formula for the energy required for the phase change of the medium (5) that the energy required for the medium to undergo a phase change is related to its mass and heat of phase change. The mass is related to the density and the volume . When the volume increases, the mass increases, resulting in an increase in the energy required for its phase change .

[0098] The heat generated by the electric arc can be calculated by the arc heating power, that is:

[0099]

[0100] (6); wherein, represents the heat generated by the electric arc,

[0101] represents the discharge time of the high-voltage power generation module. The heat transfer process of the high-voltage arc discharge heat transfer to stimulate the phase change phenomenon of the medium can be regarded as heat source heat conduction, and the heat conduction formula:

[0102] (7); wherein, represents, represents the thermal conductivity of the medium, represents the temperature gradient.

[0103] It can be seen from the above theoretical formula that: on the premise that the ambient pressure of the medium reaches the pressure required for phase change, according to the heat of phase change of the medium, the arc heating effect, and the heat transfer efficiency theory, the equation of the arc and the energy of the medium phase change can be coupled to obtain the relationship between the arc current, voltage and the energy required for the phase change of different media in different volume spaces:

[0104] (8);

[0105] Among them, represents the energy required for the gaseous phase change of the medium, unit: J; represents the heat transfer efficiency of the high-voltage arc; represents the voltage applied to the first discharge electrode and the second discharge electrode, unit: V; represents the high-voltage arc current, unit: A; represents the discharge time of the high-voltage power generation module, unit: s; represents the density of the medium, unit: kg / m 3 ; represents the volume of the medium, unit: m 3 ; represents the latent heat of phase change of the medium, unit: J.

[0106] The density of the medium will change with the changes in temperature and pressure, and the specific values can be obtained by query. In this embodiment, the heat transfer efficiency is related to the properties of the medium, taking values from 0.3 to 0.6, and the values are taken according to different media and different volumes in actual situations.

[0107] For different medium types or different working conditions, the arc current and voltage can be estimated according to formula (8). Compared with traditional chemical excitation, the present invention can precisely control the input current through the energy required for the phase change of the medium, which not only simplifies the operation process but also significantly improves safety. The present invention can be applied to the phase change heating excitation of different volumes and different media, and has good flexibility.

[0108] The above-disclosed are only the specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or variations, which should all be covered within the protection scope of the present invention.

Claims

1. A liquid-gas phase change device based on arc discharge excitation, comprising a primary chamber, and a plurality of phase change units arranged on the primary chamber and communicated with the primary chamber; characterized in that, Each of the phase change units includes a high-voltage power generation module, a first discharge electrode, a second discharge electrode and a heating tooling. The second ends of the first discharge electrode and the second discharge electrode respectively insert into the cavity of the heating tooling from two opposite connection ports of the heating tooling and are aligned; the first ends of the first discharge electrode and the second discharge electrode are respectively connected to the positive output terminal and the negative output terminal of the high-voltage power generation module. The high-voltage power generation module is used to generate direct current high voltage; the first discharge electrode and the second discharge electrode are used to transmit the direct current high voltage generated by the high-voltage power generation module into the cavity of the heating tooling; the heating tooling is used to inject a liquid medium and provide a place for the liquid medium to undergo gaseous phase change and expand under the action of the direct current high voltage; the primary chamber is used to receive the high-pressure gaseous medium released by expansion and perform pressure equalization and pressure reduction on the high-pressure gas medium and then output.

2. The liquid-gas phase change device based on arc discharge excitation according to claim 1, wherein The high-voltage power generation module includes a self-excited oscillation circuit, a transformer and a voltage multiplier rectification circuit connected in sequence. The input end of the self-excited oscillation circuit is connected to an external power supply. The positive output terminal and the negative output terminal of the voltage multiplier rectification circuit are respectively connected to the first end of the first discharge electrode and the first end of the second discharge electrode. The self-excited oscillation circuit is used to generate high-frequency alternating current; the transformer is used to generate an induced voltage under the action of the high-frequency alternating current; the voltage multiplier rectification circuit is used to multiply the induced voltage and rectify it to output direct current high voltage.

3. The liquid-gas phase change device based on arc discharge excitation according to claim 2, characterized in that, The self-excited oscillation circuit includes a capacitor C1, a capacitor C2, a resistor R1, a resistor R2, a triode V1 and a triode V2. The base of the triode V2 is connected to the first end of the resistor R2 and the positive electrode of the capacitor C2. The collector of the triode V2 is connected to the second end of the resistor R2, the base and the emitter of the triode V1. The collector of the triode V1 and the negative electrode of the capacitor C2 are respectively connected to the primary coil of the transformer. The two ends of the resistor R1 are respectively connected to the second end of the resistor R2 and the positive electrode of the capacitor C1. The negative electrode of the capacitor C1 and the emitter of the triode V2 are grounded.

4. The liquid-gas phase change device based on arc discharge excitation according to claim 1, characterized in that, The high-voltage power generation module includes a high-voltage power supply, a charging switch, a pulse capacitor, a discharge switch and a control module; the high-voltage power supply, the pulse capacitor and the charging switch are connected in sequence to form a charging loop; one end of the discharge switch is connected to the positive electrode of the pulse capacitor, and the other end is connected to the first end of the first discharge electrode. The first end of the second discharge electrode is connected to the negative electrode of the pulse capacitor; the control module is used to control the on and off of the charging switch and the discharge switch.

5. The liquid-gas phase change device based on arc discharge excitation according to claim 1, wherein The heating tooling includes a pressure tube, a rupture disk and a pressure ring; a pressure relief port is provided at the bottom of the pressure tube, the rupture disk is arranged in the pressure relief port and fixed by the pressure ring; a plurality of connection ports are provided on the side surface of the pressure tube.

6. The liquid-gas phase change device based on arc discharge excitation according to claim 5, characterized in that, The heating tooling further includes a transparent pressure cover and an observation window; an observation opening is provided at the top of the pressure tube, the transparent pressure cover is fixedly provided at the top of the pressure tube through connecting bolts, the observation window is provided between the transparent pressure cover and the pressure tube and is aligned with the observation opening; a first buffer pad is provided between the transparent pressure cover and the observation window, a second buffer pad is provided between the observation window and the pressure tube, and a plurality of sealing members are sleeved between the observation window and the pressure tube.

7. The liquid-gas phase change device based on arc discharge excitation according to claim 1, characterized in that, Both the first discharge electrode and the second discharge electrode include an electrode, a second sealing ring, a third sealing ring and a housing, the housing is sleeved on the electrode, the second sealing ring is sleeved on the first end of the electrode, the third sealing ring is sleeved on the second end of the electrode, and the sealing connection between the electrode and the heating tooling is realized through the second sealing ring and the third sealing ring.

8. The liquid-gas phase change device based on arc discharge excitation according to any one of claims 1 to 7, characterized in that The distance between the second end of the first discharge electrode and the second end of the second discharge electrode is determined according to the breakdown voltage of the phase change medium to be processed. The specific determination formula is: ； ； Among them, represents the breakdown voltage of the medium, , represents the constant in the Paschen's law of the medium, represents the initial pressure of the medium, represents the distance between the second end of the first discharge electrode and the second end of the second discharge electrode, represents an intermediate quantity, represents the secondary electron emission coefficient.

9. A method for exciting a liquid-gas phase change device, characterized in that, Applied to the liquid-gas phase change device based on arc discharge excitation as described in any one of claims 1 to 8, the excitation method includes: The DC high voltage generated by the high voltage generation module is transmitted to the cavity of the heating tooling through the first discharge electrode and the second discharge electrode, and the liquid medium in the cavity of the heating tooling is ionized and broken down to generate a high voltage arc. When the energy provided by the high voltage arc is equal to the energy required for the gaseous phase change of the medium, the gaseous phase change of the liquid medium is excited, and the pressure in the cavity of the heating tooling gradually increases. When the pressure in the cavity of the heating tooling reaches the pressure relief threshold and the rupture disk at the pressure relief port of the heating tooling ruptures, the high pressure gaseous medium is released through the pressure relief port and enters the initial volume chamber. The high pressure gaseous medium is output after equalizing and decompressing in the initial volume chamber.

10. The excitation method of the liquid-gas phase change device according to claim 9, characterized in that, The calculation formula for the energy required for the gaseous phase change of the medium is: ； Among them, represents the energy required for the gaseous phase change of the medium, represents the heat transfer efficiency of the high-voltage arc, represents the voltage applied to the first discharge electrode and the second discharge electrode, represents the high-voltage arc current, represents the discharge time of the high-voltage power generation module, represents the density of the medium, represents the volume of the medium, represents the heat of phase change of the medium.

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