Light-based heat cycle system

Abstract

To provide a heat cycle system capable of absorbing or releasing heat by efficiently using light from a light source while suppressing increase in energy consumption by the light source.SOLUTION: A heat cycle system in the present disclosure for absorbing or releasing heat by using light includes: an endless optical transmission line; a light source for emitting light having a predetermined wavelength to the optical transmission line; a heat exchange part provided downstream of the light source in the optical transmission line and absorbing or releasing heat and outputting light having a wavelength different from that of light from the light source side when a system excited by the light from the light source side is returned to a ground state; and a wavelength conversion part provided downstream of the heat exchange part in the optical transmission line, converting the wavelength of the light from the heat exchange part into the predetermined wavelength and supplying the light having the predetermined wavelength to the heat exchange part.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a heat cycle system that uses light to absorb or release heat. [Background technology]

[0002] Conventionally, optical refrigerators using dielectric mirrors with adjusted reflectivity have been known (see, for example, Patent Document 1). This optical refrigerator contains a working material that is optically excited by monochromatic laser light from a light source, and the fluorescence (anti-Stokes fluorescence) generated by optically exciting the working material has a higher average photon energy than the energy of the laser light. This makes it possible to cool the working material by emitting high photon energy. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] U.S. Patent No. 6,041,610 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the conventional optical refrigerator, the working material must be continuously irradiated with light from a light source to cool it, which increases the energy consumption of the light source. Furthermore, to increase the cooling capacity of the optical refrigerator, a high-power light source is required, but adopting a high-power light source further increases energy consumption. Furthermore, in the optical refrigerator, the fluorescence generated by excitation of the working material is absorbed by a fluorescence-absorbing material coated on the inner surface of the chamber that contains the working material, and is not reused.

[0005] Therefore, a main object of the present disclosure is to provide a heat cycle system that can efficiently utilize light from a light source to absorb or release heat while suppressing an increase in energy consumption by the light source. [Means for solving the problem]

[0006] The heat cycle system disclosed herein is a heat cycle system that absorbs or releases heat using light, and includes: an endless optical transmission path; a light source that inputs light of a predetermined wavelength into the optical transmission path; a heat exchanger that is provided downstream of the light source on the optical transmission path and absorbs or releases heat when a system excited by light from the light source returns to its ground state, and outputs light of a wavelength different from that of the light from the light source; and a wavelength conversion unit that is provided downstream of the heat exchanger on the optical transmission path and converts the wavelength of the light from the heat exchanger to the predetermined wavelength and supplies the light of the predetermined wavelength to the heat exchanger.

[0007] The heat cycle system disclosed herein includes an endless optical transmission line, a light source that inputs light of a predetermined wavelength into the optical transmission line, a heat exchanger provided downstream of the light source in the optical transmission line, and a wavelength conversion unit provided downstream of the heat exchanger in the optical transmission line. In this heat cycle system, when light of a predetermined wavelength is input from the light source into the endless optical transmission line, the heat exchanger provided downstream of the light source absorbs or releases heat and outputs light of a different wavelength from the light from the light source when a system excited by the light from the light source returns to its ground state. That is, the heat exchanger of the optical transmission line outputs light with higher energy than the light from the light source (anti-Stokes emission) or light with lower energy than the light from the light source (Stokes emission), absorbing or releasing heat corresponding to the energy difference between the input and output light. The light from the heat exchanger is then supplied to a wavelength conversion unit, which converts the wavelength of the light from the heat exchanger to the predetermined wavelength and supplies the light of the predetermined wavelength to the heat exchanger. This allows light incident on the optical transmission path from the light source to be circulated through the endless optical transmission path, making it possible to efficiently use the light from the light source to absorb or release heat in the heat exchanger. Furthermore, since there is no need to continuously input high-energy light from the light source into the optical transmission path, an increase in energy consumption by the light source can be suppressed. As a result, the heat cycle system of the present disclosure makes it possible to efficiently use the light from the light source to absorb or release heat while suppressing an increase in energy consumption by the light source. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic diagram showing a heat cycle system according to the present disclosure. FIG. [Figure 2] FIG. 2 is a schematic diagram for explaining the operation of the heat cycle system of the present disclosure. [Figure 3] FIG. 2 is a schematic diagram for explaining the operation of the heat cycle system of the present disclosure. [Figure 4] FIG. 10 is a schematic diagram illustrating another heat cycle system of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0009] Next, embodiments of the present disclosure will be described with reference to the drawings.

[0010] 1 is a schematic diagram showing a heat cycle system 1 of the present disclosure. The heat cycle system 1 shown in the figure absorbs and releases heat using light. As shown in the figure, the heat cycle system 1 includes an optical transmission line 2, a light source (excitation light source) 3 that inputs light into the optical transmission line 2, a first heat exchange unit 4 provided downstream of the light source 3 on the optical transmission line 2, a second heat exchange unit (wavelength conversion unit) 5 provided downstream of the first heat exchange unit 4 on the optical transmission line 2, and a control device 10 that controls the light source 3 and the like.

[0011] The optical transmission line 2 is formed in an endless (annular) shape using optical fiber. It includes, in addition to the first and second heat exchange units 4 and 5, a first transmission line 2a and a second transmission line 2b connected to the first and second heat exchange units 4 and 5 via optical adapters (not shown). The first and second heat exchange units 4 and 5 of the optical transmission line 2 are formed using optical fiber having a core doped with a rare earth element (additive). In this embodiment, the optical fiber forming the first and second heat exchange units 4 and 5 has an ytterbium (Yb)-doped core. However, the first and second heat exchange units 4 and 5 may also be formed using an optical fiber having a samarium (Sm)-doped core. The first and second transmission lines 2a and 2b, other than the first and second heat exchange units 4 and 5, are formed using a general optical fiber whose core is not doped with a rare earth element, which allows for easier light transmission.

[0012] The light source 3 has an exit port connected to a light incident portion 2i formed in the first transmission line 2a of the optical transmission line 2, and is capable of emitting light of a predetermined wavelength (predetermined wavelength) from the light incident portion 2i to the optical transmission line 2 (first transmission line 2a). In this embodiment, the light source 3 is a laser diode that can emit laser light (infrared light) having a wavelength of, for example, 1040 nm to the optical transmission line 2. The laser light incident from the light source 3 to the light incident portion 2i travels through the optical transmission line 2 in a clockwise direction in the drawing, as indicated by the dotted line in FIG.

[0013] The first heat exchanger 4 is located downstream of the light source 3 in the traveling direction of the laser beam and exchanges heat with a heat exchange object O1, which is a heat-generating body such as a solenoid part of a solenoid valve or an electronic control unit (ECU), to cool the heat exchange object O1. The first heat exchanger 4 is formed by winding an optical fiber having a core doped with a rare earth element in a spiral (coil) shape multiple times, and is wrapped around the heat exchange object O1 so as to be in contact (close contact) with at least a part of the heat exchange object O1.

[0014] The second heat exchange unit 5 is located downstream of the first heat exchange unit 4 in the traveling direction of the laser light and exchanges heat with the heat exchange object O2. The second heat exchange unit 5 is formed by winding an optical fiber having a core doped with a rare earth element in a spiral (coil) shape a number of times, and is wrapped around the heat exchange object O2 so as to be in contact with (close contact with) at least a portion of the heat exchange object O2. In this embodiment, the heat exchange object O2 is a heat sink into which air is blown by the fan F. That is, the heat exchange object O2 (heat sink) and the fan F constitute a radiator.

[0015] The control device 10 of the heat cycle system 1 includes a computer having a CPU, ROM, RAM, input / output interfaces, etc., various drive circuits, various logic ICs, etc. The control device 10 acquires the temperature of the heat exchange object O1 detected by a temperature sensor T attached to the heat exchange object O1, and controls the light source 3 based on the acquired temperature. Furthermore, the control device 10 controls a fan F that sends air to the heat exchange object O2.

[0016] Next, the operation of the heat cycle system 1 configured as above will be described.

[0017] In the heat cycle system 1, when a laser beam having a predetermined wavelength (for example, 1040 nm in this case) is incident from a light source 3 onto an endless optical transmission line 2, as shown in FIG. 2, in the optical fiber forming the first heat exchange section 4 downstream of the light source 3, ytterbium ions (Yb 3+ ) are excited by the laser light from the light source 3 side. That is, since the optical fiber forming the first heat exchange unit 4 is in contact with the heat exchange object O1, which is a heating element, in the first heat exchange unit 4, the ytterbium ions (Yb 3+ ) excitation is promoted.

[0018] The optical fiber forming the first heat exchanger 4 is a heat exchanger for absorbing excited ytterbium ions (Yb 3+ ) returns to its ground state, as shown in FIG. 2, it absorbs heat from the heat exchange object O1 and outputs laser light of a shorter (different) wavelength than the light from the light source 3 (here, for example, 980 nm). That is, the first heat exchange section 4 of the optical transmission path 2 absorbs heat from the heat exchange object O1 equivalent to the energy difference between the input laser light and the output laser light, and outputs laser light with higher energy than the laser light from the light source 3 side (anti-Stokes emission). This makes it possible to cool the heat exchange object O1, which is a heat-generating body, i.e., the object to be cooled, using the laser light from the light source 3 side.

[0019] The laser light from the first heat exchanger 4 is supplied to the second heat exchanger 5 via the second transmission line 2b. As shown in FIG. 3, the optical fiber forming the second heat exchanger 5 downstream of the first heat exchanger 4 is doped with ytterbium ions (Yb 3+ ) are excited by the laser light from the first heat exchanger 4. That is, since the optical fiber forming the second heat exchanger 5 is in contact with the heat exchange object (heat sink) O2 constituting the radiator, the ytterbium ions (Yb 3+ ) excitation is promoted.

[0020] The optical fiber forming the second heat exchange section 5 is a conductor of excited ytterbium ions (Yb 3+ ) returns to the ground state, as shown in Fig. 3, it releases heat to the heat exchange object O2 and also converts the wavelength of the laser light from the first heat exchange unit 4 to output laser light of the same wavelength (here, for example, 1040 nm) as the laser light from the light source 3. That is, the second heat exchange unit 5 of the optical transmission path 2 releases heat equivalent to the energy difference between the input laser light and the output laser light to the heat exchange object O2, and outputs laser light with lower energy than the laser light from the first heat exchange unit 4 (Stokes emission).

[0021] This allows the laser light incident on the light incident portion 2i from the light source 3 to be circulated through the endless optical transmission path 2, and the laser light from the light source 3 can be efficiently used to absorb heat from the heat exchange object O1, which is a heat-generating body, and release the absorbed heat from the heat exchange object O2 to the outside. In addition, since there is no need to continuously input high-energy light from the light source 3 into the optical transmission path 2, an increase in energy consumption by the light source 3 can be suppressed. As a result, the heat cycle system 1 makes it possible to efficiently use the laser light from the light source 3 to absorb or release heat while suppressing an increase in energy consumption by the light source 3.

[0022] In the above embodiment, the control device 10 of the heat cycle system 1 controls the light source 3 to input light corresponding to at least the amount of light loss in the optical transmission path 2 to the light input unit 2i in accordance with the temperature of the heat exchange object O1 detected by the temperature sensor T. More specifically, when the light source 3 outputs a continuous laser beam, the control device 10 increases the output of the laser beam when the temperature of the heat exchange object O1 has not reached a predetermined target temperature, and decreases the output of the laser beam when the temperature of the heat exchange object O1 has reached the target temperature. When the light source 3 outputs a pulsed laser beam, the control device 10 shortens the interval between pulses when the temperature of the heat exchange object O1 has not reached the predetermined target temperature, and lengthens the interval between pulses when the temperature of the heat exchange object O1 has reached the target temperature. This makes it possible to adjust the temperature of the heat exchange object O1 exchanging heat with the first heat exchange unit 4 to a desired temperature while effectively suppressing an increase in energy consumption by the light source 3.

[0023] Furthermore, in the above embodiment, the first heat exchanger 4 and the second heat exchanger 5 of the optical transmission line 2 are each formed of an optical fiber having a core doped with a rare earth element (additive) such as ytterbium. This allows the first and second heat exchangers 4 and 5 to absorb or release heat when ions of the rare earth element excited by the laser light from the light source 3 return to the ground state.

[0024] However, in the heat cycle system 1, the optical fibers forming the first heat exchange section 4 and the second heat exchange section 5 may be different optical fibers as long as they have cores doped with a rare earth element (additive). Furthermore, in the heat cycle system 1, the optical fibers forming the first and second transmission lines 2a, 2b may be the same or different as long as they allow light to easily pass through.

[0025] Each of the first and second heat exchange units 4 and 5 is formed of an optical fiber wound around the heat exchange object O1 or O2 so as to contact at least a part of the heat exchange object O1 or O2. This makes it possible to efficiently cool or heat (radiate heat) the heat exchange object O1 or O2 by the first and second heat exchange units 4 and 5 while preventing the heat cycle system 1 from becoming large.

[0026] In the heat cycle system 1, the first heat exchange unit 4 may output laser light having a wavelength (e.g., 1040 nm) longer than (different from) the wavelength (e.g., 980 nm) of the laser light from the light source 3 and release heat to the heat exchange object O1 as the heating object when the ions of the additive (e.g., rare earth element) doped in the core return to the ground state after being excited by the laser light from the light source 3. In this case, the second heat exchange unit 5 may absorb heat from the heat exchange object O2 as the heat absorption object and output laser light having the same wavelength (e.g., 980 nm) as the wavelength of the laser light from the light source 3 when the ions of the additive (e.g., rare earth element) doped in the core return to the ground state after being excited by the laser light from the first heat exchange unit 4. This makes it possible to heat the heat exchange object O1, i.e., the heating object, using the laser light from the light source 3.

[0027] 4, a wavelength converter 50 may be used in place of the second heat exchange unit 5 that releases or absorbs heat when the system excited by the laser light from the first heat exchange unit 4 returns to the ground state. That is, in the heat cycle system 1, a wavelength converter 50 that does not have the function of releasing or absorbing heat (or has low heat release or heat absorption performance) may be used in place of the second heat exchange unit 5, and the wavelength converter 50 may convert the wavelength of the laser light from the first heat exchange unit 4 to the same wavelength as the wavelength of the laser light from the light source 3.

[0028] The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present disclosure. Furthermore, the above-described embodiment is merely a specific form of the invention described in the Summary of the Invention, and does not limit the elements of the invention described in the Summary of the Invention. [Industrial Applicability]

[0029] The invention of the present disclosure can be used in the heat cycle system manufacturing industry, etc. [Explanation of symbols]

[0030] 1 heat cycle system, 2 optical transmission path, 2a first transmission path, 2b second transmission path, 2i light incident section, 3 light source, 4 first heat exchange section, 5 second heat exchange section, 10 control device, 50 wavelength converter, F fan, O1, O2 heat exchange object, T temperature sensor.

Claims

1. A heat cycle system that uses light to absorb or release heat, an endless optical transmission line; a light source that inputs light of a predetermined wavelength into the optical transmission line; a heat exchanger that is provided downstream of the light source in the optical transmission path and that absorbs or releases heat and outputs light of a wavelength different from that of the light from the light source when a system excited by the light from the light source returns to a ground state; a wavelength conversion unit provided downstream of the heat exchange unit in the optical transmission line, which converts the wavelength of light from the heat exchange unit to the predetermined wavelength and supplies the light of the predetermined wavelength to the heat exchange unit; A heat cycle system comprising:

2. The heat cycle system according to claim 1, The wavelength conversion unit is a second heat exchange unit that emits or absorbs heat when a system excited by light from the heat exchange unit returns to its ground state, converts the wavelength of the light from the heat exchange unit to the specified wavelength, and outputs light of the specified wavelength.

3. 3. The heat cycle system according to claim 2, The heat cycle system, wherein the heat exchange unit and the second heat exchange unit are formed by optical fibers having a core doped with a rare earth element.

4. The heat cycle system according to claim 3, A heat cycle system, wherein each of the heat exchange unit and the second heat exchange unit is formed by the optical fiber wound around a heat exchange object so as to contact at least a portion of the heat exchange object.

5. The heat cycle system according to any one of claims 1 to 4, A heat cycle system further comprising a control device that controls the light source so that light equivalent to at least the light loss in the optical transmission path is incident on the optical transmission path depending on the temperature of the heat exchange object that exchanges heat with the heat exchange section.