Heat exchange device and heat exchange method

Abstract

A heat exchange device (NS) includes a container (YK) in which a gas (KT), as well as a liquid (ET) having a solvent (YB) and a solute (YS), are sealed, the solute (YS) affecting surface-activating properties at a surface where the liquid (ET) makes contact with the gas (KT), and the liquid (ET) being such that the higher the concentration of the solute (YS) is, the lower the surface tension of the liquid (ET) becomes. A high-temperature region (KR) of the container (YK) is at a temperature below the boiling point of the solvent (YB) and the boiling point of the solute (YS), while a low-temperature region (TR) of the container (YK) is at a temperature below the solidification point of the solvent (YB).

Description

[Technical field]

[0001] The present disclosure relates to a heat exchange device and a heat exchange method. [Background technology]

[0002] In a conventional two-phase heat pipe, an example of which is the heat pipe-type heat transfer device described in Patent Document 1, for example, a liquid (e.g., water) and a surfactant (e.g., alcohol) are used. In the two-phase heat pipe, in a high-temperature region, the alcohol evaporates earlier than the water, i.e., becomes gas earlier, whereas in a low-temperature region, the alcohol condenses earlier than the water, i.e., becomes liquid earlier. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 3416731 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned two-phase heat pipe, the above-mentioned alcohol undergoes a phase transition between gas and liquid as described above, and therefore the heat pipe needs to have a strength capable of withstanding the change in pressure inside the heat pipe caused by the phase transition.

[0005] An object of the present disclosure is to provide a heat exchange device and a heat exchange method including a container that does not need to have the strength to withstand changes in internal pressure caused by the phase transition of a solute between gas and liquid. [Means for solving the problem]

[0006] The heat exchange device according to the present disclosure includes a container in which a gas and a liquid having a solvent and a solute are sealed, the solute affecting the surface activity of the interface where the liquid comes into contact with the gas and the higher the concentration of the solute, the lower the surface tension of the liquid, the higher the high temperature region of the container is at a temperature below the boiling point of the solvent and the boiling point of the solute, and the low temperature region of the container is at a temperature below the freezing point of the solvent. Effect of the Invention

[0007] The heat exchange device according to the present disclosure has the advantage that the container does not need to be strong enough to withstand changes in internal pressure caused by the solute undergoing a phase transition between gas and liquid. [Brief description of the drawings]

[0008] [Figure 1] Fig. 1A shows the configuration of the heat exchanger NS of embodiment 1. Fig. 1B shows the operation (part 1) of the heat exchanger NS of embodiment 1. Fig. 1C shows the operation (part 2) of the heat exchanger NS of embodiment 1. Fig. 1D shows the operation (part 3) of the heat exchanger NS of embodiment 1. [Diagram 2] Fig. 2A shows the configuration of the heat exchanger ns of the comparative example. Fig. 2B shows the operation (part 1) of the heat exchanger ns of the comparative example. Fig. 2C shows the operation (part 2) of the heat exchanger ns of the comparative example. Fig. 2D shows the operation (part 3) of the heat exchanger ns of the comparative example. [Diagram 3] Fig. 3A shows the configuration of the heat exchanger NS of embodiment 2. Fig. 3B shows the operation (part 1) of the heat exchanger NS of embodiment 2. Fig. 3C shows the operation (part 2) of the heat exchanger NS of embodiment 2. Fig. 3D shows the operation (part 3) of the heat exchanger NS of embodiment 2. [Figure 4] Fig. 4A shows the configuration of the heat exchanger NS of embodiment 3. Fig. 4B shows the operation (part 1) of the heat exchanger NS of embodiment 3. Fig. 4C shows the operation (part 2) of the heat exchanger NS of embodiment 3. Fig. 4D shows the operation (part 3) of the heat exchanger NS of embodiment 3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] An embodiment of a heat exchange device according to the present disclosure will be described.

[0010] Embodiment 1. First Embodiment The heat exchange device NS of the first embodiment will be described.

[0011] <Basic configuration of the first embodiment> The heat exchange device NS of the first embodiment may basically have the following configuration.

[0012] The present invention includes a container YK in which a gas KT and a liquid ET having a solvent YB and a solute YS are sealed, the solute YS affecting the surface activity of an interface where the liquid ET comes into contact with the gas KT, and the higher the concentration of the solute YS, the lower the surface tension of the liquid ET; The high temperature region KR of the container YK is a temperature lower than the boiling point of the solvent YB and the boiling point of the solute YS, The low temperature region TR of the container YK is at a temperature below the freezing point of the solvent YB.

[0013] Configuration of First Embodiment FIG. 1 shows the configuration and operation of a heat exchanger NS according to the first embodiment.

[0014] The configuration of the heat exchanger NS of the first embodiment will be described with reference to FIG. 1A.

[0015] The heat exchange device NS of the first embodiment includes a container YK for performing heat exchange. The container YK includes a liquid ET and a gas KT for heat exchange. The liquid ET includes a solvent YB (e.g., water) and a solute YS (e.g., a surfactant (e.g., sodium dodecyl sulfate (SDS))).

[0016] The container YK and the liquid ET are roughly divided into a high temperature region KR, which is relatively high temperature, and a low temperature region TR, which is relatively low temperature.

[0017] The high temperature region KR is a temperature range below the boiling point of the solvent YB and below the boiling point of the solute YS.

[0018] The low temperature region TR is a temperature range that includes the freezing point of the solvent YB and exceeds the freezing point of the solute YS.

[0019] For example, it is assumed that the solvent YB is water. Under the above assumption, the high temperature region KR is below 100 degrees, which is the boiling point of water. On the other hand, the low temperature region TR is above 0 degrees, which is the freezing point of water. As the solute YS, it is desirable to use, for example, a surfactant whose precipitation temperature is below 0 degrees.

[0020] The gas KT is present inside the liquid ET, in other words, at a position near the center of the container YK. Due to the presence of the gas KT, an interface exists between the liquid ET and the gas KT, which are in contact with each other. As a result, capillary waves are generated.

[0021] Operation of the First Embodiment The operation of the heat exchanger NS of the first embodiment will be described with reference to FIGS. 1B to 1D.

[0022] In the low temperature region TR, the solvent YB becomes a solid KO, that is, it solidifies, and this causes the concentration of the solute YS (surfactant) to increase.

[0023] On the other hand, in the high temperature region KR, the solvent YB melts from a solid KO to a liquid ET, thereby decreasing the concentration of the solute YS (surfactant).

[0024] Generally, the higher the concentration of the solute YS (surfactant), the lower the surface tension. Therefore, when comparing the interfacial tension in the high temperature region KR with the interfacial tension in the low temperature region TR, the interfacial tension in the high temperature region KR is relatively high, whereas the interfacial tension in the low temperature region TR is relatively low.

[0025] Comparative Example FIG. 2 shows the configuration and operation of a heat exchanger ns of a comparative example.

[0026] As described above, the heat exchanger ns of the comparative example is a conventional two-phase heat pipe, an example of which is the heat pipe type heat transfer device described in Patent Document 1. As described above, the heat exchanger ns uses, for example, a liquid et (e.g., water) and a surfactant (e.g., alcohol).

[0027] As described above, in the high temperature region kr, the surfactant evaporates, i.e., vaporizes, earlier than the liquid et, whereas in the low temperature region tr, the surfactant condenses, i.e., liquefies earlier than the liquid et.

[0028] In the heat exchange device ns of the comparative example, the alcohol undergoes a phase transition between a gas kt and a liquid e. Therefore, the heat pipe, i.e., the container yk, needs to have a strength capable of withstanding the change in pressure inside the container yk caused by the phase transition. Effects of the First Embodiment As described above, in the heat exchanger NS of the embodiment 1, the liquid ET undergoes a phase transition between the liquid ET and the solid KO. Therefore, in the heat exchanger NS of the embodiment 1, unlike the heat exchanger ns of the comparative example, it is possible to obtain an effect that the container YK does not need to have a strength capable of withstanding a change in internal pressure caused by the phase transition of the alcohol between the gas kt and the liquid et.

[0029] <Modification of the first embodiment> In the heat exchanger NS of the modified example, for example, micelles or vesicles may be used as the solute YS (surfactant) and the concentration distribution of the solute YS may be varied by phase change to aggregates. In theory, it is desirable that the higher the temperature, the less likely aggregates are to occur. In reality, however, the higher the temperature, the more likely aggregates are to occur. However, it is expected that the same effect as that of the heat exchanger NS of the above-mentioned embodiment 1 can be obtained.

[0030] Embodiment 2. Second Embodiment A heat exchanger NS according to the second embodiment will be described.

[0031] <Basic configuration of the second embodiment> The heat exchange device NS of the second embodiment may basically have the following configuration.

[0032] The present invention includes a container YK in which a gas KT and a liquid ET having a solvent YB and a solute YS are sealed, the solute YS affecting the surface activity of an interface where the liquid ET comes into contact with the gas KT, and the lower the concentration of the solute YS, the lower the surface tension of the liquid ET; The high temperature region KR of the container YK is a temperature lower than the boiling point of the solvent YB and the boiling point of the solute YS, The low temperature region TR of the container YK is at a temperature below the freezing point of the solute YS.

[0033] Configuration of the Second Embodiment FIG. 3 shows the configuration and operation of the heat exchanger NS of the second embodiment.

[0034] The configuration of the heat exchanger NS of the second embodiment will be described with reference to FIG. 3A.

[0035] The heat exchange device NS of the second embodiment includes a container YK for performing heat exchange. The container YK includes a liquid ET and a gas KT for heat exchange. The liquid ET has a solvent YB (e.g., water) as in the first embodiment. On the other hand, the liquid ET has a solute YS (e.g., an electrolyte (e.g., sodium chloride (NaCl)) unlike the first embodiment.

[0036] Operation of the Second Embodiment The operation of the heat exchanger NS of the second embodiment will be described with reference to FIGS. 3B to 3D.

[0037] In general, there is a phenomenon in which the surface tension increases depending on the concentration of the solute YS (electrolyte) in water.

[0038] In the heat exchange device NS of embodiment 2, in line with the above phenomenon, the freezing point of the solute YS (electrolyte) is lower than the freezing point of the solvent YB, and as a result, in the low temperature region TR, the solute YS (electrolyte) freezes before the solvent YB.

[0039] In general, the "solubility" of a solute (electrolyte), which is the upper limit of the amount that a solute (electrolyte) can dissolve in a solvent, is temperature dependent, and the higher the temperature, the higher the solubility. A solute (electrolyte) that is not completely dissolved in a solvent and solidifies does not contribute to the above-mentioned surface tension of the solvent.

[0040] In the heat exchanger NS of the second embodiment, the low temperature region TR is a temperature range in which the solute YS (electrolyte) does not completely dissolve and precipitates as a solid, whereas the high temperature region KR is a temperature range below the boiling point of the solvent YB and in which the solute YS (electrolyte) is sufficiently completely dissolved.

[0041] In the low temperature region TR, the solute YS (electrolyte) becomes solid, that is, solidifies into a solid electrolyte KD, and the concentration of the solute YS (electrolyte) decreases.

[0042] On the other hand, the "solubility" is higher in the high temperature region KR than in the low temperature region TR. As a result, the solute YS (electrolyte) dissolves from a solid to a liquid in the high temperature region KR. That is, the concentration of the solute YS (electrolyte) increases in the high temperature region KR.

[0043] Comparing the interfacial tension in the high temperature region KR with the interfacial tension in the low temperature region TR, similarly to the first embodiment, the interfacial tension in the high temperature region KR is relatively high, whereas the interfacial tension in the low temperature region TR is relatively low.

[0044] Effects of the Second Embodiment As described above, in the heat exchanger NS of embodiment 2, similarly to the heat exchanger NS of embodiment 1, the container YK, unlike the container yk of the comparative example (shown in FIG. 2), has the advantage that it does not need to be strong enough to withstand the change in internal pressure caused by the phase transition of alcohol between gas and liquid.

[0045] <Modifications of the First and Second Embodiments> In the heat exchange devices NS of embodiments 1 and 2, it is desirable that the inner diameter of the container YK (the radius of the container YK in the short direction) exceeds the minimum bubble radius (Laplace diameter) determined by the viscosity of the liquid ET so as to prevent a layer of only gas KT from forming.

[0046] Embodiment 3. Third embodiment A heat exchanger NS according to a third embodiment will be described.

[0047] <Basic configuration of the third embodiment> The heat exchange device NS of the second embodiment may basically have the following configuration.

[0048] The system includes a container YK in which a gas KT and a liquid ET having a solvent YB and a solute YS are sealed, The container YK has an inner wall subjected to a hydrophobic surface treatment, the hydrophobic surface treatment being denser in the low temperature region TR of the container YK than in the high temperature region KR of the container YK.

[0049] Configuration and Operation of Third Embodiment FIG. 4 shows the configuration and operation of a heat exchanger NS according to the third embodiment.

[0050] The configuration of the heat exchanger NS of the third embodiment will be described with reference to FIG. 4A.

[0051] The heat exchange device NS of the third embodiment includes a container YK for performing heat exchange, similar to the first and second embodiments. The container YK includes a liquid ET and a gas KT for heat exchange, similar to the first and second embodiments.

[0052] In the heat exchanger NS of embodiment 3, in order to control the magnitude of the interfacial tension in the low temperature region TR and the high temperature region KR as in embodiments 1 and 2, instead of varying the concentration of the solute YS (e.g., a surfactant) in the heat exchanger NS of embodiment 1 and varying the concentration of the solute YS (e.g., an electrolyte) in the heat exchanger NS of embodiment 2, a distributed surface treatment HS is applied to the inside of a container YK as shown in Figures 4B to 4D.

[0053] As the distributed surface treatment HS described above, for example, a hydrophobic surface treatment (e.g., a surface treatment using a silane compound) is applied to the inner wall surface of the container YK at a relatively high concentration in the low temperature region TR, while at a relatively low concentration in the high temperature region KR.

[0054] Due to the difference in concentration of the surface treatment HS described above, the rate constant of the phase change in the low temperature region TR becomes relatively large, while the rate constant of the phase change in the high temperature region KR becomes relatively small.

[0055] Effects of the Third Embodiment As described above, in the heat exchanger NS of embodiment 3, the hydrophobic surface treatment HS is distributed over the inner wall surface of the container YK, and thus, like the heat exchanger NS of embodiments 1 and 2, unlike the container yk of the comparative example (shown in FIG. 2), it is possible to obtain the effect that the container does not need to have the strength to withstand the change in internal pressure caused by the phase transition of alcohol between gas and liquid.

[0056] Embodiment 4. Fourth embodiment A heat exchanger NS according to a fourth embodiment will be described.

[0057] <Basic configuration of the fourth embodiment> The heat exchange device NS of the fourth embodiment may basically have the following configuration.

[0058] The system includes a container YK in which a gas KT and a liquid ET having a solvent YB and a solute YS are sealed, By selectively irradiating the container YK with light, the surface tension of the liquid ET in the low temperature region TR of the container YK is reduced.

[0059] Configuration of Fourth Embodiment The configuration of the heat exchanger NS of the fourth embodiment is similar to that of the heat exchanger NS of the first embodiment, etc., except for the configuration of selectively irradiating light as described above.

[0060] <Operation of the Fourth Embodiment> The heat exchanger NS of the embodiment 4 controls the surface tension in the same manner as the heat exchanger NS of the embodiment 1, etc., but unlike the heat exchanger NS of the embodiment 1, etc., it performs the control by selectively irradiating light to a substance whose surface tension changes when irradiated with light. The control using light is described in, for example, the document "Manipulation of small particles at solid liquid interface: light driven diffusioosmosis."

[0061] One example of the above-mentioned substance is a substance whose surface tension changes as a result of cis-trans isomerization using light with a wavelength of 360 nm.

[0062] In the heat exchanger NS of the fourth embodiment, when the above-mentioned substance is irradiated with light having a wavelength absorbed by the double bond, the surface tension of the substance is reduced. More specifically, by irradiating light only to the substance in the low temperature region TR, only the surface tension in the low temperature region TR is reduced. On the other hand, the substance in the high temperature region KR is not irradiated with light, and the surface tension in the high temperature region KR is maintained unchanged.

[0063] As described above, in the heat exchanger NS of the fourth embodiment, a substance whose surface tension changes when irradiated with light is used, and the substance is selectively irradiated with light to selectively change the surface tension. As a result, like the heat exchanger NS of the first embodiment, and unlike the heat exchanger ns of the comparative example, the container YK does not need to have the strength to withstand the change in internal pressure caused by the phase transition of alcohol between gas and liquid can be obtained.

[0064] Embodiment 5. Fifth embodiment A heat exchanger NS according to the fifth embodiment will be described.

[0065] <Basic configuration of the fifth embodiment> The heat exchange device NS of the fifth embodiment may basically have the following configuration.

[0066] A sealed container YK contains a gas KT and a liquid ET having a solvent YB and a solute YS, The surface tension of the liquid ET in the low temperature region TR of the container YK is reduced by making the potential in the low temperature region TR of the container YK different from the potential in the high temperature region KR of the container YK.

[0067] Configuration of Fifth Embodiment The configuration of the heat exchanger NS of the fifth embodiment is similar to that of the heat exchanger NS of the first embodiment, etc., except that the potential in the low temperature region TR and the potential in the high temperature region KR of the container YK are made different from each other.

[0068] <Operation of the Fifth Embodiment> The heat exchanger NS of the fifth embodiment controls the surface tension in the same manner as the heat exchanger NS of the first embodiment, etc., but unlike the heat exchanger NS of the first embodiment, etc., it uses electricity to control the surface tension.

[0069] In general, most liquids have an electric double layer structure on the surface, and a surface charge exists. When the potential is changed from the potential at which the surface charge becomes zero (point of zero charge: PZC), the surface tension decreases according to the electrocapillary curve.

[0070] The heat exchanger NS of the fifth embodiment has a structure in which a potential is applied to the liquid ET in the low temperature region TR, while a potential is not applied to the liquid ET in the high temperature region KR, thereby making the magnitude of the surface tension in the low temperature region TR and the magnitude of the surface tension in the high temperature region KR different from each other.

[0071] Generally, under natural potential conditions where no external potential is applied, there exists a phenomenon in which the surface tension is in a high state near the apex of a capillary curve.

[0072] In order to utilize the above-mentioned phenomenon, in the heat exchanger NS of the fifth embodiment, a plurality of electrodes are installed from the high temperature region KR to the low temperature region TR. This makes it possible to apply a potential to the liquid ET. More specifically, by applying a potential to the low temperature region TR and not applying a potential to the high temperature region KR, a surface tension distribution is realized in which the surface tension in the low temperature region TR is lower than the surface tension in the high temperature region KR.

[0073] Effect of the Fifth Embodiment As described above, in the heat exchanger NS of the fifth embodiment, the surface tension is selectively changed by selectively applying a potential to the low temperature region TR and the high temperature region KR. As a result, in the heat exchanger NS of the fifth embodiment, similar to the heat exchanger NS of the first embodiment, and unlike the heat exchanger ns of the comparative example, the container YK does not need to have the strength to withstand the change in internal pressure caused by the phase transition of alcohol between gas and liquid.

[0074] The above-described embodiments may be combined with each other without departing from the gist of the present disclosure, and components in each embodiment may be appropriately deleted or modified, or other components may be added.

[0075] <Additional Notes> Various aspects of the present disclosure are set forth below.

[0076] <Appendix 1> A container is provided in which a gas and a liquid having a solvent and a solute are sealed, the solute affecting the surface activity of an interface between the liquid and the gas, and the higher the concentration of the solute, the lower the surface tension of the liquid; the high temperature region of the vessel is at a temperature below the boiling point of the solvent and the boiling point of the solute; The cold region of the container is at a temperature below the freezing point of the solvent. heat exchange equipment.

[0077] <Appendix 2> A container is provided in which a gas and a liquid having a solvent and a solute are sealed, the solute affecting the surface activity of an interface where the liquid comes into contact with the gas, and the lower the concentration of the solute, the lower the surface tension of the liquid; the high temperature region of the vessel is at a temperature below the boiling point of the solvent and the boiling point of the solute; The cold region of the container is at a temperature below the freezing point of the solute. heat exchange equipment.

[0078] <Appendix 3> The container has a radius that is greater than a minimum bubble radius determined by the viscosity of the liquid. 3. The heat exchange device according to claim 1 or 2.

[0079] <Appendix 4> A container containing a gas and a liquid having a solvent and a solute, The container has a hydrophobic surface treatment applied to an inner wall of the container, the hydrophobic surface treatment being denser in a low temperature region of the container than in a high temperature region of the container. heat exchange equipment.

[0080] <Appendix 5> A container containing a gas and a liquid having a solvent and a solute, selectively irradiating the container with light to reduce the surface tension of the liquid in cooler regions of the container; heat exchange equipment.

[0081] <Appendix 6> A container containing a gas and a liquid having a solvent and a solute, By making the electric potential in the low temperature region of the container different from the electric potential in the high temperature region of the container, the surface tension of the liquid in the low temperature region of the container is reduced. heat exchange equipment.

[0082] <Appendix 7> A heat exchange method comprising the steps of: performing heat exchange using the heat exchange device according to claim 1, 2, 4, 5, or 6. [Industrial Applicability]

[0083] The heat exchange device according to the present disclosure can be used to reduce the pressure resistance of a container. [Explanation of symbols]

[0084] NS heat exchanger, YK vessel, KR high temperature region, TR low temperature region, ET liquid, YB solvent, YS solute, KO solid, KT gas.

Claims

1. A container is provided in which a gas and a liquid having a solvent and a solute are sealed, the solute affecting the surface activity of an interface between the liquid and the gas, and the higher the concentration of the solute, the lower the surface tension of the liquid; the high temperature region of the vessel is at a temperature below the boiling point of the solvent and the boiling point of the solute; The cold region of the container is at a temperature below the freezing point of the solvent. heat exchange equipment.

2. A container is provided in which a gas and a liquid having a solvent and a solute are sealed, the solute affecting the surface activity of an interface where the liquid comes into contact with the gas, and the lower the concentration of the solute, the lower the surface tension of the liquid; the high temperature region of the vessel is at a temperature below the boiling point of the solvent and the boiling point of the solute; The cold region of the container is at a temperature below the freezing point of the solute. heat exchange equipment.

3. The container has a radius that is greater than a minimum bubble radius determined by the viscosity of the liquid. The heat exchange device according to claim 1 or 2.

4. A container containing a gas and a liquid having a solvent and a solute, selectively irradiating the container with light to reduce the surface tension of the liquid in cooler regions of the container; heat exchange equipment.

5. A heat exchange method comprising the step of: performing heat exchange using the heat exchange device according to claim 1 , 2 or 4 .

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