Heat exchange unit, heat exchange device and heat exchange method

Abstract

To improve heat exchange appropriately.SOLUTION: A heat exchange unit according to the present disclosure comprises: a base part electrically connected to a reference potential point; a plurality of heat radiation members supported on the base part; a discharge electrode formed of a conductive material; and a voltage application part that applies a voltage between the heat radiation members and the discharge electrode to cause a corona discharge and generate ions.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a heat exchange unit, a heat exchange device, and a heat exchange method.

Background Art

[0002] When turbulence occurs in a fluid used in a fluid machine or a heat exchanger, the pressure loss increases, which may cause a problem. In contrast, technologies for controlling a fluid by utilizing an ionization action such as a plasma actuator have been developed.

[0003] For example, Patent Document 1 below discloses an automotive air conditioner including a blower mounted on an automobile, an air outlet opened in the passenger compartment of the automobile, a flow passage connecting the blower and the air outlet to guide the air blown from the blower to the air outlet, and a plasma actuator disposed in the flow passage to change the direction of the air flow by generating plasma.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, when using a plasma actuator as in the automotive air conditioner described in Patent Document 1 above, there are problems such as low fluid acceleration ability by the plasma actuator and insufficient acceleration, and large power consumption of the plasma actuator.

[0006] In view of the above problems, an object of the present disclosure is to provide a heat exchange unit, a heat exchange device, and a heat exchange method that can appropriately improve heat exchange performance.

Means for Solving the Problems

[0007] To solve the above-described problems and achieve the object, the heat exchange unit according to the present disclosure includes a base electrically connected to a reference electric potential point, a plurality of heat radiating members supported by the base, a discharge electrode formed of a conductive material, a voltage application unit that applies a voltage between the heat radiating member and the discharge electrode to generate corona discharge and generate ions.

[0008] To solve the above-described problems and achieve the object, the heat exchange device according to the present disclosure includes the heat exchange unit described above, a fan that applies pressure to air by rotating, a drive unit that drives the fan, a casing having an intake port for allowing air to flow in, and the heat exchange unit disposed at at least one of the four corners of the casing.

[0009] To solve the above-described problems and achieve the object, the heat exchange method according to the present disclosure is a heat exchange method of a heat exchange unit having a base electrically connected to a reference electric potential point, a plurality of heat radiating members supported by the base, and a discharge electrode formed of a conductive material, and includes applying a voltage between the heat radiating member and the discharge electrode to generate corona discharge and generate ions.

Advantages of the Invention

[0010] According to the present disclosure, the heat exchange performance can be appropriately improved.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

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Figure 9

DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Note that the present disclosure is not limited to the embodiments described below.

[0013] (Configuration of Heat Exchange Unit) First, the configuration of the heat exchange unit according to the present disclosure will be described with reference to FIG. 1. FIG. 1 is a schematic diagram showing a configuration example of the heat exchange unit according to the present disclosure. As shown in FIG. 1, the heat exchange unit 100 according to the present disclosure includes a heat sink 102, a voltage application unit 106, and a discharge electrode 104.

[0014] The heat sink 102 includes a base 120 electrically connected to a reference electrical potential point 108, and a plurality of heat dissipation members 122 having one end connected to the base 120. Here, an example of the structure of the heat sink 102 will be described with reference to FIG. 2. FIG. 2 is a schematic diagram showing an example of the structure of the heat sink according to the present disclosure. As shown in FIG. 2, the heat sink 102 has a plurality of heat dissipation members 122 arranged in parallel at equal intervals on one surface of the base 120 and protruding perpendicularly from one surface of the base 120. The heat sink 102 is electrically connected to the reference electrical potential point 108.

[0015] The heat dissipation member 122 of this embodiment has a flat plate shape as shown in FIG. 2. Note that the shape of the heat dissipation member 122 is not limited to a flat plate shape. The heat dissipation member 122 may be, for example, pin fins having a pincushion shape or corrugated fins formed by bending flat plate-shaped fins into a waveform. Also, the interval between a specific heat dissipation member 122 and the adjacent heat dissipation member 122 among the plurality of heat dissipation members 122 may be determined after performing a thermal fluid analysis in order to optimize the convective heat transfer of air.

[0016] As the material of the heat dissipation member 122, a metal with high thermal conductivity such as aluminum, an aluminum alloy, copper, or a copper alloy may be used. Furthermore, the emissivity in the heat radiation from the surface of the heat dissipation member 122 may be improved by performing anodizing treatment on the surface of the heat dissipation member 122.

[0017] The discharge electrode 104 is provided at a position separated from the tip of the heat dissipation member 122 by a predetermined distance. Here, with reference to FIG. 3, the position where the discharge electrode 104 is provided will be described. FIG. 3 is a schematic diagram showing the structure of the first embodiment of the heat exchange unit according to the present disclosure. As shown in FIG. 3, the discharge electrode 104 may be provided at a position separated by a predetermined distance from the other end with respect to one end that connects to the base 120 of the heat dissipation members 122 arranged at equal intervals on the base 120 of the heat sink 102. Here, the predetermined distance may be arbitrarily set. For example, when the height of the heat dissipation member 122 is 2.5 cm, it may be from 2.5 to 5 cm.

[0018] The discharge electrode 104 is formed of a material having conductivity. The discharge electrode 104 may be formed of, for example, a metal such as aluminum, copper, stainless steel, or tungsten. The discharge electrode 104 is formed in a wire shape and has a pointed tip in a needle shape. The discharge electrode 104 generates ions by causing a corona discharge when a voltage is applied by a voltage application unit 106. Note that corona discharge is a type of discharge, and when the potential difference applied between the electrodes reaches the corona critical voltage, dielectric breakdown occurs in the gas between the electrodes, electrons are emitted, and a current flows.

[0019] The reference potential point 108 is the reference potential of an electrical circuit, also known as ground or earth. The reference potential point 108 may be realized by ground or earth. The ground may be frame grounding or signal grounding. The earth may be frame earth or signal earth.

[0020] The voltage application unit 106 applies a voltage to the heat dissipation member 122 to generate a potential difference between the heat dissipation member 122 and the discharge electrode 104. The voltage application unit 106 applies a DC voltage to the heat dissipation member 122. The voltage application unit 106 generates a DC voltage from, for example, an AC voltage supplied from a power transmission network. In this case, the voltage application unit 106 may include a rectifier circuit, a transformer, a smoothing capacitor, etc. The voltage application unit 106 may apply a voltage using an independent power source such as a lithium-ion battery, a nickel-cadmium battery, a lead-acid battery, or an alkaline battery. The voltage application unit 106 generates a corona discharge between the heat dissipation member 122 and the discharge electrode 104 by generating a potential difference between the heat dissipation member 122 and the discharge electrode 104.

[0021] The voltage application unit 106 applies, for example, a DC or AC high voltage of 10 kV to the discharge electrode 104 electrically connected to the voltage application unit 106. Note that the applied voltage of 10 kV is an example, and the applied voltage of the voltage application unit 106 ranges from 5 to 20 kV, and the polarity may be either negative or positive. Also, the voltage application unit 106 only needs to be electrically connected so that a potential difference capable of generating a corona discharge between the discharge electrode 104 and the surface of the heat sink 102 can be generated, and it does not need to be physically connected to the heat sink 102. That is, the heat sink 102 and the voltage application unit 106 may be connected to different reference potential points 108.

[0022] Here, the position where the discharge electrode 104 is provided will be described with reference to FIG. 4. FIG. 4 is a schematic diagram showing the structure of the second embodiment of the heat exchange unit according to the present disclosure. As shown in FIG. 4, the discharge electrode 104 may be provided between a heat dissipation member 122a having one end connected to the base portion 120 of the heat sink 102 and the heat dissipation member 122b. Note that the discharge electrode 104 is not limited to being provided only between any two of the plurality of heat dissipation members 122 as shown in FIG. 4, and may be provided between all adjacent heat dissipation members 122, or may be provided between any number of heat dissipation members 122. Further, the position where the discharge electrode 104 is provided may be, for example, a position separated from the base portion 120 by 0 to 2.5 cm when the height of the heat dissipation member 122 is 2.5 cm.

[0023] The discharge electrode 104 is formed of an insulator, and further includes an insulating cover C provided on the side in the direction away from the base portion 120. Here, the insulating cover C may be formed of polyethylene, polyvinyl chloride (PVC), fluororubber, silicone rubber, ethylene-propylene rubber, or the like. As shown in FIG. 4, the insulating cover C may be provided over the entire surface of one side of the discharge electrode 104. Thereby, since corona discharge can be generated in the direction of the base portion 120, ions can be efficiently attracted to the surface of the heat dissipation member 122 and the base portion 120.

[0024] (Operation of the heat exchange unit) Next, the operation of the heat exchange unit 100 according to the present disclosure will be described with reference to FIGS. 5 and 6. FIG. 5 is a first diagram for explaining the action of ions generated by the discharge electrode according to the present disclosure. As shown in FIG. 5, when a voltage is applied by a voltage application unit 106 between the heat dissipation member 122 and the discharge electrode 104, corona discharge is generated by the applied voltage, and electrons are ionized from nitrogen molecules. As a result, positively charged ions (nitrogen ions) 130 are attracted to the base portion 120 connected to the reference potential point 208. Note that as shown in FIG. 5, the air flow velocity 150 is in a state where a boundary layer in which the velocity near the surface of the base portion 120 is reduced due to the viscosity of the air is formed.

[0025] And ion 130 acts as shown in FIG. 6. FIG. 6 is a second diagram for explaining the action of ions generated by the discharge electrode according to the present disclosure. As shown in FIG. 6, the ions 130 attracted to the base 120 become part of the boundary layer formed near the surface of the base 120 of the air, and the air flow velocity 152 near the base 120 increases. Therefore, since the temperature boundary layer thickness decreases and the heat transfer rate by air convection increases, the heat exchange efficiency of the heat exchange unit 100 is improved. Further, in the above embodiment, although described as the surface of the base 120, the same phenomenon can occur on the surface of the heat radiating member 122, and the flow velocity can be increased.

[0026] In the present embodiment, the heat sink 102 of the heat exchange unit 100 has a structure in which one end of a plurality of heat radiating members 122 is supported by the base 120, but is not limited thereto. The heat sink 102 may support a plurality of heat radiating members 122 with a heat transfer member penetrating the plurality of heat radiating members 122, for example, a heat transfer pipe through which a heat medium flows inside. Further, without providing the heat radiating member 122, the plate-shaped base 120 may be used as the heat radiating member. Also in this case, the flow velocity of the surface of the member that dissipates heat can be increased by ions, and the heat transfer rate can be increased.

[0027] (Configuration of Heat Exchange Device) Next, the configuration of the heat exchange device 10 according to the present disclosure will be described with reference to FIG. 7. FIG. 7 is a diagram showing a configuration example of the heat exchange device according to the present disclosure. The heat exchange device 10 according to the present disclosure is mainly composed of the indoor unit 11 for air conditioning shown in FIG. 7.

[0028] As shown in FIG. 7, the indoor unit 11 for air conditioning includes a casing 17, a drive unit 18 which is a motor disposed inside the casing 17, a fan 19 rotated by the drive unit 18, a suction port 20 into which indoor air flows, a suction port 21 that guides air from the suction port 20 to the fan 19, a heat exchanger 22 that heats or cools the air, and an air outlet 23 that discharges the air into the room as main elements.

[0029] Around the fan 19, a heat exchanger 22 is provided in a substantially rectangular shape surrounding the fan 19. FIG. 8 is a diagram showing the structure of the heat exchanger in the heat exchange device according to the present disclosure. As shown in FIG. 8, the heat exchanger 22 is composed of a flat plate portion 22A having a substantially planar shape and a corner portion 22B with a small radius of curvature connecting adjacent flat plate portions 22A.

[0030] In the present embodiment, the corner portion 22B of the heat exchanger 22 may be realized by the heat exchange unit 100 described above. That is, it can be said that the heat exchange unit 100 is arranged at at least one of the four corners of the casing 17.

[0031] Here, since the fan 19 is circular and the casing 17 is rectangular, a region with a slow flow velocity is formed in the circumferential direction of the fan 19. Therefore, inside the casing 17, the flow velocity distribution becomes non-uniform. Regarding this point, FIG. 9 shows the result of numerical fluid analysis using CFD (Computer Fuid Dynamics) for the air inside the casing 17 of the indoor unit 11 for air conditioning. FIG. 9 is a diagram showing an image of the result of numerical fluid analysis in the heat exchange device according to the present disclosure.

[0032] As shown in the analysis result image of FIG. 9, in the regions 210 at the four corners of the casing, the flow stagnates and a region with a slow air flow velocity is formed. At the electrical component board installation position 212, a drift flow 214 occurs, and it can be seen that there is a bias in the flow velocity in the region where the heat exchanger 22 inside the indoor unit 11 for air conditioning is arranged. Therefore, the indoor unit 11 for air conditioning can increase the air flow velocity and improve the heat transfer efficiency by providing the heat exchange unit 100 described above at a location where the air flow velocity in the casing 17 is slow.

[0033] (Configuration and operation) The heat exchange unit 100 according to the present disclosure includes a base 120 electrically connected to a reference electrical potential point 108, a plurality of heat dissipation members 122 supported by the base 120, a discharge electrode 104 formed of a conductive material, and a voltage application unit 106 that applies a voltage between the heat dissipation member 122 and the discharge electrode 104 to generate a corona discharge and generate ions.

[0034] According to this configuration, the ions generated by the corona discharge can be attracted to the heat dissipation member 122 and the base 120, and the flow velocity of the boundary layer near the heat dissipation member 122 and the base 120 can be increased. Therefore, the heat transfer efficiency of the heat exchange unit 100 can be improved. Accordingly, it is possible to provide the heat exchange unit 100 that can appropriately improve the heat exchange performance.

[0035] In the heat exchange unit 100 according to the present disclosure, the discharge electrode 104 is provided at a position separated from the heat dissipation member by a predetermined distance.

[0036] According to this configuration, even with a small number of discharge electrodes 104, the ions generated by generating a corona discharge due to the potential difference between the discharge electrode 104 and the base 120 can be attracted to the surface of the heat dissipation member 122 and the surface of the base 120, and the flow velocity of the boundary layer formed on these surfaces can be increased. Therefore, the heat transfer efficiency can be improved. Accordingly, it is possible to provide the heat exchange unit 100 that can appropriately improve the heat exchange performance.

[0037] In the heat exchange unit 100 according to the present disclosure, the heat dissipation member has a plate shape. According to this configuration, the flow velocity on the surface of the heat dissipation member can be further increased.

[0038] The heat exchange unit 100 according to the present disclosure includes a plurality of heat dissipation members, and the heat dissipation members are arranged in parallel with adjacent heat dissipation members. According to this configuration, the heat dissipation efficiency can be made higher.

[0039] In the heat exchange unit 100 according to the present disclosure, the discharge electrode 104 is provided between at least two adjacent heat dissipation members 122 among the plurality of heat dissipation members.

[0040] According to this configuration, ions generated by causing corona discharge due to the potential difference between the discharge electrode 104 and the base 120 can be accurately attracted to the surface of the heat radiating member 122 or the surface of the base 120. Therefore, since the flow velocity of the boundary layer formed on these surfaces can be increased, the heat transfer efficiency can be improved. Accordingly, a heat exchange unit 100 capable of appropriately improving the heat exchange performance can be provided.

[0041] The heat exchange unit 100 according to the present disclosure further includes an insulating cover C formed of an insulator and provided on the side in the direction away from the base 120 of the discharge electrode 104.

[0042] According to this configuration, since ions are not generated by corona discharge in the direction away from the base 120 of the discharge electrode 104, ions can be more accurately attracted to the surface of the heat radiating member 122 or the surface of the base 120. Accordingly, a heat exchange unit 100 capable of appropriately improving the heat exchange performance can be provided.

[0043] The heat exchange device 10 according to the present disclosure includes the heat exchange unit described above, a fan 19 that applies pressure to air by rotating along a rotation axis, a drive unit 18 that drives the fan 19, a casing 17 having an air inlet for allowing air to flow in, and a heat exchange unit 100 disposed at at least one of the four corners of the casing 17.

[0044] According to this configuration, the flow velocity at the four corners of the casing 17 where the flow velocity decreases can be increased by ions. Therefore, the heat exchange performance of the heat exchange device 10 can be improved. Accordingly, a heat exchange device 10 capable of appropriately improving the heat exchange performance can be provided.

[0045] The heat exchange method according to the present disclosure is a heat exchange method of a heat exchange unit 100 having a base 120 electrically connected to a reference electric potential point, a plurality of heat dissipation members 122 supported by the base 120, and a discharge electrode 104 formed of a conductive material. A voltage is applied between the heat dissipation member 122 and the discharge electrode 104 to generate corona discharge and generate ions.

[0046] According to this configuration, the ions generated by the corona discharge can be attracted to the heat dissipation member 122 and the base 120, and the flow velocity of the boundary layer in the vicinity of the heat dissipation member 122 and the base 120 can be increased. Therefore, the heat transfer efficiency of the heat exchange unit 100 can be improved. Accordingly, the heat exchange performance can be appropriately improved.

[0047] As described above, the embodiments of the present disclosure have been described, but the embodiments are not limited by the contents of these embodiments. In addition, the above-described components include those that can be easily assumed by those skilled in the art, those that are substantially the same, and those within the so-called equivalent range. Furthermore, the above-described components can be combined as appropriate. Furthermore, various omissions, substitutions, or changes of the components can be made without departing from the gist of the above-described embodiments.

Description of Reference Numerals

[0048] 10 Heat exchange device 11 Indoor unit for air conditioning 17 Casing 18 Driving unit 19 Fan 20, 21 Suction ports 22 Heat exchanger 23 Air outlet 100 Heat exchange unit 102 Heat sink 104 Discharge electrode 106 Voltage application unit 108 Reference electric potential point 120 Base 122 Heat dissipation member

Claims

1. A base electrically connected to a reference electric potential point, a plurality of heat dissipation members supported by the base, a discharge electrode formed of a conductive material, and a voltage application unit that applies a voltage between the heat dissipation member and the discharge electrode to generate corona discharge and generate ions, a heat exchange unit.

2. The discharge electrode is provided at a position spaced a predetermined distance from the heat dissipation member, The heat exchange unit according to claim 1.

3. The heat dissipation member is in a plate shape, The heat exchange unit according to claim 1.

4. Having a plurality of the heat dissipation members, The heat dissipation members are arranged in parallel with adjacent heat dissipation members, The heat exchange unit according to claim 3.

5. The discharge electrode is provided between at least two adjacent ones of the plurality of heat dissipation members, The heat exchange unit according to claim 4.

6. Further comprising an insulating cover formed of an insulator and provided on a side in a direction away from the base of the discharge electrode, The heat exchange unit according to claim 1.

7. The heat exchange unit according to any one of claims 1 to 6, a fan that sends air toward the heat exchange unit, a drive unit that drives the fan, a casing having an air inlet for allowing air to flow in, and the heat exchange unit disposed at at least one of the four corners of the casing, a heat exchange device.

8. A heat exchange method of a heat exchange unit having a base electrically connected to a reference electric potential point, a plurality of heat dissipation members supported by the base, and a discharge electrode formed of a conductive material, the method comprising applying a voltage between the heat dissipation member and the discharge electrode to generate corona discharge and generate ions, A heat exchange method.

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