CN201134972Y - An AC Plasma Arc Heater - Google Patents

Abstract

An AC plasma arc heater includes six electrodes, a magnetic field coil, an inlet ring and a mixing chamber. The six electrodes are equally spaced at 60° and connected to the mixing chamber by flanges to form a star structure. Each electrode There is an air inlet ring at each root, and the magnetic field coil is wound on the outside of the electrodes. The six electrodes are divided into two groups, which are respectively connected to the power frequency AC power supply A, B, and C to form six arcs. The utility model adopts a three-phase AC power supply as a power supply, which improves the utilization rate of the power supply and reduces the cost; adopts a star-shaped structure composed of six electrodes to form two groups of "star-shaped" loads composed of six arcs. When the electrode is subjected to a small arc current, the heater can be operated at high power, which reduces the burnout of the electrode by the heater, overcomes the influence of the cyclone on the parameters of the flow field, and realizes high power and large flow of the AC plasma arc heater. , high pressure, medium and low enthalpy, long-term efficient and stable operation.

Description

An AC Plasma Arc Heater

technical field

The utility model relates to a plasma arc heater, in particular to an AC plasma arc heater, which can be applied to aircraft aerodynamic thermal ground simulation tests or the fields of chemical industry, smelting, electric power and the like.

Background technique

The plasma arc heater uses the plasma arc to heat the gas to generate a high-temperature jet or flow field. It has the advantages of wide temperature range and concentrated energy. The temperature adjustment range can be adjusted from hundreds to tens of thousands of degrees Celsius. The high-temperature thermal environment faced by aircraft flying in the air. Plasma arc heater is also called plasma arc spray gun. Its unique high temperature performance is also widely used in industrial fields such as boiler pulverized coal ignition and stable combustion, special waste incineration, hazardous waste treatment, metal smelting and cutting.

At present, in the field of aircraft aerothermal technology research at home and abroad, DC plasma arc heaters are mainly used. The main technical forms are tubular type, long segment type, laminated type and magnetically stable type. Its characteristic is that its power supply is a DC power supply, the construction cost is high, and the utilization rate of the power supply is low. Generally, the utilization rate of the power supply can only reach about 50%. In the field of industrial applications, domestic plasma arc spray guns are mainly DC hot cathode type. AC plasma arc heaters have not been widely used for a long time, mainly because many technical problems of stable high-voltage and high-power AC plasma arc heaters need to be overcome.

Utility model content

The technical problem of the utility model is: to overcome the deficiencies of the prior art, to provide an AC plasma arc heater, which is powered by a three-phase AC power supply, which improves the utilization rate of the power supply and reduces the cost;

The technical problem further solved by the utility model is: the star structure composed of six electrodes realizes the high-power operation of the heater, reduces the burning loss of the electrodes by the heater, overcomes the influence of the cyclone on the flow field parameters, and realizes the AC Plasma arc heater has high power, large flow, high pressure, medium and low enthalpy, long-term efficient and stable operation.

The technical scheme of the utility model is: an AC plasma arc heater includes: six electrodes, a magnetic field coil, an intake ring and a mixing chamber, the six electrodes are equally divided into 60° in space, and the six electrodes and the mixing chamber Flange connection is adopted to form a star structure. There is an intake ring at the root of each of the six electrodes. The magnetic field coil is wound outside the six electrodes. The six electrodes are connected to two sets of three-phase AC power supply to form six plasma arcs.

The six electrodes are tubular and adopt an inner-outer sandwich structure.

The mixing chamber is hollow and circular, and adopts an inner-coat sandwich structure.

The magnetic field coil adopts copper flat wire or water-cooled copper tube.

The power supply voltage of the three-phase AC power supply is 10KV.

The working principle of the utility model is: the working gas enters the interior of the plasma arc heater tangentially through the intake ring at the root of the electrode, the AC power supply ionizes the working gas into plasma, and forms a rotating air flow with a certain speed distribution on the inner surface of the electrode. The plasma arc is stabilized at the center of the electrode, one end of the plasma arc, the arc root, is attached to the inner surface of the electrode, and the other end of the plasma arc is pulled toward the center of the mixing chamber under the action of the axial force of the rotating airflow, forming a star-shaped load circuit .

The utility model has the following advantages compared with the prior art:

(1) The utility model adopts a three-phase AC power supply as a power supply, which improves the utilization rate of the power supply and reduces the cost.

(2) The utility model adopts a star structure composed of six electrodes to form two sets of "star" loads composed of six arcs. When each electrode bears a small arc current, the heater can achieve a large High power operation reduces the burnout of the heater to the electrode, overcomes the influence of the cyclone on the flow field parameters, and realizes the AC plasma arc heater with high power, large flow, high pressure, medium and low enthalpy, and long-term high-efficiency and stable operation.

Description of drawings

Fig. 1 is the structural representation of the utility model embodiment;

Fig. 2 is the enthalpy-pressure characteristic curve of the utility model 40MW AC arc heater.

Detailed ways

Below in conjunction with accompanying drawing and concrete implementation example the utility model is described in detail:

A high-voltage and high-power AC plasma arc heater includes six electrodes, a magnetic field coil, an inlet ring and a mixing chamber. The six electrodes are equally spaced at 60° and connected to the mixing chamber to form a star structure. The two electrodes adopt exactly the same structure, and there is an intake ring at the root of each electrode, and the magnetic field coil is wound outside each electrode, and the six electrodes are connected to two sets of three-phase AC power supply when working. When the AC plasma arc heater is working, the working gas enters the interior of the AC plasma arc heater tangentially through the intake ring at the root of each electrode, and the three-phase AC power supply ionizes the working gas into plasma, which forms on the inner surface of each electrode The rotating air flow with a certain speed distribution makes the plasma arc stable at the center of the electrode. One end of the plasma arc, the arc root, is attached to the inner surface of the electrode, and the other end of the plasma is pulled toward the center of the mixing chamber under the action of the axial force of the rotating air flow. In the center, a star-shaped load circuit is formed, and the magnetic field coil is used to accelerate the rotation of the arc root in the direction of the airflow, reducing the burning loss of the arc root to the electrode, so that the AC plasma arc heater can run stably for a long time.

Each electrode is designed to be tubular. The inner diameter and length of the tube are mainly determined according to the arc current and gas flow. The length is 200-800mm, the diameter is 20-55mm, and the tube wall thickness is 5-8mm. For forced water cooling, the water pressure depends on the pressure of the mixing chamber. Generally, the pressure of the cooling water is about 0.2MPa to 0.5MPa higher than the pressure of the mixing chamber. The thickness of the interlayer of the inner and outer jackets is 1-3mm. Made of stainless steel; the mixing chamber is hollow and circular, with an inner and outer jacket sandwich structure for forced water cooling. The water pressure depends on the pressure of the mixing chamber. Generally, the cooling water pressure is about 0.2MPa to 0.5MPa higher than the mixing chamber pressure. The interlayer thickness of the inner and outer jackets is 1-3mm, the inner jacket is made of red copper, and the outer jacket is made of stainless steel; the magnetic field coil is made of red copper flat wire or water-cooled red copper tube; the voltage of the three-phase AC power supply is 10kV.

Implementation example

As shown in Figure 1, an AC plasma arc heater includes six electrodes 1, a magnetic field coil 2, an inlet ring 4 and a mixing chamber 5, and each of the six electrodes 1 has a length of 800 mm and a diameter of 55 mm. The thickness of the pipe wall is 6mm, the thickness of the interlayer of the inner and outer jackets is 2mm, the inner jacket is made of red copper, and the outer jacket is made of stainless steel; the mixing chamber 5 is hollow and circular, the thickness of the inner jacket is 2mm, the inner jacket is made of red copper, and the outer jacket stainless steel material. The six electrodes 1 are evenly arranged in space at 60° to each other and are flanged to the mixing chamber 5 to form a star structure. There is an inlet ring 4 at the root of each electrode, and the magnetic field coil 2 is wound on the outside of the six electrodes 1. Each electrode 1 is respectively connected to two sets of three-phase AC power supply to form six plasma arcs 3. The voltage of the three-phase AC power supply is 10KV. The maximum arc power of the AC plasma arc heater with this structure is about 40MW, and the maximum arc current of each electrode The maximum arc chamber pressure is 1500A, and the maximum arc chamber pressure is 10MPa. The specific enthalpy-pressure characteristics are shown in Figure 2.

Claims (8)

1. An AC plasma arc heater is characterized in that: it comprises six electrodes (1), a magnetic field coil (2), an inlet ring (4) and a mixing chamber (5), and the six electrodes (1) are located in a spatial position It is equally divided into 60° and connected with the mixing chamber (5) to form a star-shaped structure. Each of the roots of the six electrodes (1) has an inlet ring (4), and the magnetic field coil (2) is wound around the six electrodes ( 1), the six electrodes (1) are respectively connected to two sets of three-phase AC power sources to form six plasma arcs (3). 2. An AC plasma arc heater according to claim 1, characterized in that the six electrodes (1) are tubular, with a sandwich structure inside and outside. 3. An AC plasma arc heater according to claim 2, characterized in that: the inner casing of the six electrodes (1) is made of red copper, the outer casing is made of stainless steel, and the interlayer thickness is 1-3mm. 4. An AC plasma arc heater according to claim 1 or 2, characterized in that: the length of the six electrodes (1) is 200-800 mm, the diameter is 20-55 mm, and the tube wall thickness is 5 -8mm. 5. An AC plasma arc heater according to claim 1, characterized in that: said mixing chamber (5) is hollow and circular, with a sandwich structure inside and outside. 6. An AC plasma arc heater according to claim 5, characterized in that: the inner casing of the mixing chamber (5) is made of red copper, the outer casing is made of stainless steel, and the thickness of the interlayer is 1-3mm. 7. An AC plasma arc heater according to claim 1, characterized in that: said magnetic field coil (2) is made of copper flat wire or water-cooled copper tube. 8. An AC plasma arc heater according to claim 1, characterized in that: said three-phase AC power supply voltage is 10KV.

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