JP5108488B2 - Rankine cycle equipment using capillary force - Google Patents

Description

  The present invention relates to a capillary force utilization Rankine cycle device that uses a capillary force to drive a working fluid.

As one of the irreversible heat cycle devices, a Rankine cycle device that is a theoretical cycle device of a steam turbine cycle device is known (see, for example, Non-Patent Document 1). In this cycle device, a water supply pump for supplying water liquefied by the condenser to the boiler is required. A system using the thermosyphon effect is known as a system that eliminates this water supply pump and establishes the Rankine cycle device (see, for example, Patent Document 1).
Ebara Times No. 211 April 2006 JP-A-60-62611

  In the former technique described above, since a water supply pump is provided, it is necessary to input external energy in addition to heat. On the other hand, in the latter technique, since gravity is used for the circulation of the working fluid, there is a problem that the arrangement and size of each element constituting the Rankine cycle apparatus are greatly restricted.

  In view of the above facts, an object of the present invention is to obtain a capillary force Rankine cycle device that can operate without relying on external energy other than heat and has a high degree of freedom in arrangement and dimensions.

The Rankine cycle apparatus utilizing capillary force according to the first aspect of the present invention includes an expansion element that expands a supplied gas-phase working fluid and converts kinetic energy into external work, and an operation of the gas phase discharged from the expansion element. Condensation elements that condense the fluid and independent capillary tubes that are aggregates of independent linear tubes that are not in communication with each other, and are provided over the entire cross-section of the flow path of the working fluid and condensed by the condensation elements capillary structure for driving the liquid-phase working fluid by capillary forces, and evaporating the working fluid of the capillary structure in by supplying heat from the downstream end of the flow direction of the working fluid in the capillary structure and a, and evaporation element comprising a pressurized heat unit Ru is.

  In the Rankine cycle apparatus utilizing capillary force according to the first aspect, when the working fluid that has been expanded by the expansion element and worked to the outside by kinetic energy flows into the condenser, it is condensed and changes in phase from the gas phase to the liquid phase. The liquid-phase working fluid is driven by capillary force in the capillary structure of the evaporation element, and is evaporated (vaporized) by being heated by the heating unit during the driving. In this way, since the working fluid is continuously evaporated inside the capillary structure, the liquid-phase working fluid is continuously applied by the capillary force so as to maintain the liquid surface position in the capillary structure. Inhaled. Further, in the evaporation element, since the capillary structure is provided over the entire surface of the flow path cross section, the vapor flow toward the inflow side of the liquid phase working fluid is unlikely to occur. For this reason, the generated steam flows to the expansion element side due to the increased vapor pressure (vapor pressure difference with the condensing element).

  As described above, in this Rankine cycle device using capillary force, a circulating flow in which the working fluid circulates in the order of the evaporation element, the expansion element, and the condensation element is generated without applying external energy other than heat. In other words, the evaporation element can generate a gas-phase working fluid (supplied to the expansion element) while self-supplying the liquid-phase working fluid with capillary force. Since gravity is not used to circulate this working fluid, there are no restrictions on the arrangement and dimensions of each element compared to a configuration using, for example, a pump device, and the degree of freedom of arrangement and dimensions of each element. Is expensive.

As described above, the Rankine cycle device using capillary force according to claim 1 can operate without depending on external energy other than heat, and has a high degree of freedom in arrangement and dimensions.
Further, in this Rankine cycle apparatus using capillary force, the capillary structure is heated so as to face the traveling direction of the liquid-phase working fluid, so that the working fluid vapor is generated on the downstream end side of the capillary structure. be able to. For this reason, the pressure loss accompanying vapor | steam passing through a capillary structure can be reduced, and the vapor pressure of a working fluid can be raised.

The Rankine cycle apparatus utilizing capillary force according to the invention of claim 2 is an expansion element that expands a supplied gas-phase working fluid to convert kinetic energy into external work, and an operation of the gas phase discharged from the expansion element. A condensing element for condensing a fluid, and an independent capillary which is an assembly of independent linear pipes which are communicated with the condensing element via a liquid pipe and communicated via the expansion element and a vapor pipe and are not in communication with each other capillary structure for driving the working fluid of the constructed liquid phase by capillary forces as a group, and, of the capillary structure in by supplying heat from the downstream end of the flow direction of the working fluid in the capillary structure and a, and evaporation element comprising a pressurized hot section Ru evaporation of working fluid.

  In the Rankine cycle apparatus utilizing capillary force according to claim 2, when the working fluid that has been expanded by the expansion element and worked to the outside by kinetic energy flows into the condenser, it is condensed and changes in phase from the gas phase to the liquid phase. This liquid-phase working fluid is driven by the capillary force generated by the capillary structure of the evaporation element, flows into the evaporation element (capillary structure) through the liquid tube, and is heated by the heating unit while being driven by the capillary structure. Evaporates (vaporizes). In this way, since the working fluid is continuously evaporated inside the capillary structure, the liquid-phase working fluid is continuously applied by the capillary force so as to maintain the liquid surface position in the capillary structure. Inhaled. On the other hand, since the generated working fluid vapor (gas phase working fluid) does not easily flow to the liquid tube side with respect to the capillary structure, it is caused to flow toward the expansion element through the vapor pipe due to the vapor pressure (vapor pressure difference with the condensing element). The

  As described above, in this Rankine cycle device using capillary force, a circulating flow in which the working fluid circulates in the order of the evaporation element, the expansion element, and the condensation element is generated without applying external energy other than heat. In other words, the evaporation element can generate a gas-phase working fluid (supplied to the expansion element) while self-supplying the liquid-phase working fluid with capillary force. In this Rankine cycle device using capillary force, the evaporating element is an independent element connected to the expansion element and the condensing element via the pipes, respectively, so that the flow direction against the gravity of the liquid phase and gas phase working fluid is restricted. And there is a high degree of freedom in the arrangement and dimensions of each element.

  Thus, the capillary force utilization Rankine cycle device according to claim 2 can operate without relying on external energy other than heat, and has a high degree of freedom in arrangement and dimensions.

Further, in this Rankine cycle apparatus using capillary force, the capillary structure is heated so as to face the traveling direction of the liquid-phase working fluid, so that the working fluid vapor is generated on the downstream end side of the capillary structure. be able to. For this reason, the pressure loss accompanying vapor | steam passing through a capillary structure can be reduced, and the vapor pressure of a working fluid can be raised.

The capillary force utilizing Rankine cycle device according to the invention described in claim 3 is the capillary force utilizing Rankine cycle device according to claim 1 or 2 , wherein the capillary structure has a part on the heat supply side by the heating unit. For the capillary force action part constituting the part on the inflow side of the liquid phase working fluid, the part to be heated is made of a material having high thermal conductivity.

In the Rankine cycle apparatus using capillary force according to the third aspect , the portion of the capillary structure made of a material having high thermal conductivity is intensively heated by the heating unit. For this reason, the vapor generation site in the capillary structure (evaporation element) can be controlled (set to a desired site). Further, the effects of claims 1 and 2 can be enhanced.

  As described above, the capillary force-based Rankine cycle device according to the present invention can be operated without relying on external energy other than heat, and has an excellent effect that the degree of freedom of arrangement and dimensions is high.

In the following description, “embodiment” and “first modified example” are read as “reference example”, and “second modified example” is read as “embodiment”.
The capillary force utilization Rankine cycle apparatus 10 which concerns on embodiment of this invention is demonstrated based on drawing. First, a principle model and a modification of the capillary force utilizing Rankine cycle device 10 will be described with reference to FIGS. 1 to 6, and then an example of application of the capillary force utilizing Rankine cycle device 10 to an automobile will be described with reference to FIGS. 7 to 10. It will be explained based on this.

(Description of the principle model)

  FIG. 1 is a system configuration diagram showing a schematic overall configuration of a capillary force utilization Rankine cycle device 10. As shown in this drawing, the capillary force Rankine cycle device 10 includes an expander 12 for taking out work, a condenser 14 as a condensing element, an evaporator 16 as an evaporating element, the expander 12 and a condensing unit. The main part is a circulation path 18 that communicates the condenser 14 and the evaporator 16 in series in this order.

  The circulation path 18 communicates the pipe 20 that connects the expander 12 and the condenser 14, the liquid pipe 22 that is a liquid pipe that communicates the condenser 14 and the evaporator 16, and the evaporator 16 and the expander 12. And a gas pipe 24 as a steam pipe.

  The expander 12 has a mechanical element (not shown) provided inside. This mechanical element is adapted to convert thermal energy of a gaseous working fluid (hereinafter also referred to as “steam”) flowing into the expander 12 into mechanical energy through kinetic energy. For example, a steam turbine or a positive displacement expander (scroll expander) to which rotational force is applied by expansion of steam can be adopted as the mechanical element. The expander 12 has an internal mechanical element mechanically connected to a load 26. Thereby, the expander 12 drives the load 26 with the mechanical energy converted from said heat energy. As the load 26, for example, a generator that converts mechanical (rotational) energy into electrical energy, a pump or windmill that converts mechanical energy into fluid kinetic energy, a compressor that converts mechanical energy into pressure energy, and the like are adopted. Can do.

  The condenser 14 is configured to condense the working fluid by dissipating heat (cooling the steam) to the low-pressure steam after the work flowing in from the expander 12 through the pipe 20. That is, a liquid-phase working fluid (hereinafter sometimes referred to as “liquid”) is discharged from the outlet of the evaporator 16. Thus, the condenser 14 is configured as a heat exchanger between the working fluid and the refrigerant.

  The evaporator 16 is configured to perform a pump function that imparts a driving force for the working fluid to circulate through the circulation path 18 to the working fluid, and a steam generation function that converts the liquid into high-pressure steam that evaporates the liquid. The evaporator 16 shown in FIG. 1 schematically shows these functions. Hereinafter, the evaporator 16 will be specifically described.

  As shown in FIG. 2, the evaporator 16 includes a shell 28, a capillary structure 30 provided in the shell 28, and a heating unit 32. Although not shown, the shell 28 has an upstream end 28 </ b> A side in the working fluid flow direction indicated by an arrow F connected in a liquid-tight manner to the liquid pipe 22, and a downstream end 28 </ b> B side in an arrow F direction in an air-tight manner connected to the gas pipe 24. Has been.

  Therefore, in the evaporator 16, the working fluid that has flowed from the liquid pipe 22 is configured to reach the gas pipe 24 through the flow path cross section formed by the shell 28. The capillary structure 30 extends over the entire cross section of the flow path of the shell 28, in other words, the inside of the shell 28 so that substantially all of the working fluid flowing in from the liquid pipe 22 passes through the inside and reaches the gas pipe 24. Is provided.

  In this embodiment, the capillary structure 30 is a porous body made of a sintered metal such as a ceramic sintered body, acid-etched porous glass, titanium, nickel, stainless steel, or the like. The capillary structure 30 is configured to drive (suck) the liquid that has reached the upstream end 30 </ b> A side in the direction of arrow F in the direction of arrow F with a capillary force.

  In the evaporator 16, as shown in FIG. 2, the heating unit 32 supplies (heats) heat to the capillary structure 30 from the downstream end 30 </ b> B side in the arrow F direction with respect to the capillary structure 30. Yes. Thereby, in the evaporator 16, the liquid driven by the capillary force of the capillary structure 30 is evaporated by the heating by the heating unit 32, and vapor is generated. In the evaporator 16, the vapor flow to the upstream end 30 </ b> A side of the capillary structure 30 in which the liquid is driven by capillary force is restricted, so that the vapor pressure in the evaporator 16 is increased and the vapor pressure is increased. Due to the pressure difference from the vapor pressure of the condenser 14, the vapor flows in the direction of arrow F.

  For this reason, in the evaporator 16, since the liquid sucked into the capillary structure 30 by capillary force is continuously evaporated (discharged) from the liquid surface, the liquid on the upstream end 30A side of the capillary structure 30 is The capillary structure 30 is continuously sucked into the capillary structure 30 by a capillary force so as to compensate for the liquid level, and is driven in the direction of arrow F macroscopically. And since the vapor | steam produced by the heating of the heating part 32 flows to the arrow F direction as above-mentioned, in the capillary force utilization Rankine cycle apparatus 10, as FIG. 1 shows, the circulation path 18 is made into the evaporator 16, the expander 12, In this configuration, a circulating flow Ff of the working fluid that circulates in the order of the condenser 14 is generated.

This point will be supplemented with reference to FIG. FIG. 3 schematically shows one capillary part (pore) 35 constituting the capillary structure 30, and is supplied with heat from the heating part 32. An interface of solid (ceramics, glass, metal, etc.), liquid, and vapor (gas) constituting the body 30 is generated. Therefore, the pressure of the liquid P _L, when the pressure of the steam and P _G, the capillary unit 35, in accordance with the law of Laplace, the pressure or pressure differential feed the liquid to the vapor side (P G _{-P L)} occurs.

Here, when the surface tension of the liquid is γ, the radius of the capillary portion 35 is R, and the contact angle of the liquid with respect to the inner wall surface of the capillary portion 35 is θ, the pressure (P _G -P _L ) is
P _G −P _L = γ {1 / (R / cos θ) + 1 / (R / cos θ)}
= (2γcosθ) / R
It becomes. In addition, when many capillary parts (pores) 35 are provided, it can be considered substantially the same.
In the evaporator 16, the above (P _G −P _L ) can be grasped as the boosting amount of the pump function. As shown in FIG. 4, typical working fluids such as water (surface tension: 0.072 [N / m]), ethanol (surface tension: 0.023 [N / m]), methylene chloride (surface tension: 0.028 [N / m]), HFC-R134a (surface tension: 0.008 [N / m]), HCFC-225 (surface tension: 0.016 [N / m]), the radius of the capillary portion 35 Depending on R, a theoretical pressure (P _G -P _L ) that can be increased can be obtained. In FIG. 4, assuming that a capillary structure 30 in which a large number of linear capillary portions 35 having an inner diameter D (inner radius R) is used as the capillary structure 30, a pure water fluid and a temperature are used as the working fluid. It is a calculation result when normal temperature and contact angle θ are 0 (maximum wettability of capillary part 35).

  Further, it is desirable that the diameter of the pores (pores) of the capillary structure 30 (corresponding to twice the above-mentioned inner radius R) is made smaller toward the downstream end 30B side in the working fluid flow direction. In this embodiment, the pores of the capillary structure 30 are 10 μm or less at the downstream end 30B.

  Next, the operation of this embodiment will be described.

  In the Rankine cycle apparatus 10 using the capillary force configured as described above, when the heating of the liquid in the capillary structure 30 by the heating unit 32 is started, the liquid on the downstream end 30B side of the capillary structure 30 evaporates. Along with this evaporation, in the capillary structure 30 (each capillary part 35), the liquid is sucked by the capillary force so as to supplement the liquid level. For this reason, the capillary structure 30 (inside liquid) functions like a check valve that prohibits vapor from flowing toward the upstream end 30A.

Therefore, the capillary force available Rankine cycle system 10, the shell 28 increasing pressure (evaporator 16) in _{(P G} or _P G -P _L) is, steam flow towards the direction of arrow F is generated. The steam is supplied to the expander 12 through the gas pipe 24 and expands in the expander 12 to give mechanical energy to the machine element. The mechanical energy applied (converted) by the expander 12 is converted into various works by a load 26 connected to the expander 12.

  The low-pressure steam expanded by the expander 12 is introduced into the condenser 14 through the pipe 20. In the condenser 14, the vapor is condensed or liquefied while dissipating heat to the refrigerant or the like. This liquid flows into the shell 28 from the upstream end 28 </ b> A through the liquid pipe 22. When the liquid reaches the upstream end 30 </ b> A end of the capillary structure 30, the liquid is sucked into the capillary structure 30 by capillary force.

  As described above, in the Rankine cycle device 10 using the capillary force, the heating fluid 32 is started by the heating unit 32 of the evaporator 16, and the circulation of the working fluid in the circulation path 18 is started. This circulation is maintained by maintaining the heating. Therefore, in the Rankine cycle apparatus 10 using capillary force, mechanical energy (work) can be taken out from the expander 12 and consumed by the load 26 without inputting external energy other than heat.

  As described above, in the Rankine cycle apparatus 10 using capillary force, the evaporator and the pump are integrated, in other words, the steam generation function and the fluid drive function are integrated into the evaporator 16, and the system is It can be simplified.

  Further, in the Rankine cycle apparatus 10 using capillary force, for example, a configuration including a pump driven by external power (general Rankine cycle), external input power other than heat (for example, electrical and mechanical energy) ) Is not necessary, and the efficiency of the Rankine cycle can be improved. This point will be described together with application examples described later.

  Furthermore, in the Rankine cycle apparatus 10 using capillary force, the capillary structure 30 (and the heating unit 32) applies a driving force to the working fluid. In other words, a pump that converts mechanical work into a driving force (pressure) of the fluid. Since there is no movable part like this, the reliability of the entire apparatus can be improved. In addition, the number of parts of the pump (and its accessories) can be reduced, and the cost of the entire apparatus can be reduced.

  Further, here, in the capillary force utilization Rankine cycle device 10, since the capillary structure 30 is provided over the entire surface of the flow path cross section of the shell 28, the capillary structure 30 is operated by heating the capillary structure 30 with the heating unit 32 as described above. A circulating flow Ff in which the fluid circulates in the circulation path 18 can be generated. In other words, in the Rankine cycle device 10 using the capillary force, the wick for driving the liquid by the capillary force is used over the entire length of the system, such as a configuration having a thermosyphon, or a capillary type heat pipe. Since it is possible to circulate the circulation path 18 in the working fluid without providing it, the arrangement and dimensions of the expander 12, the condenser 14, and the evaporator 16 are not limited.

  Furthermore, in the Rankine cycle apparatus 10 using capillary force, the expander 12, the condenser 14, and the evaporator 16 are communicated with each other through the pipe 20, the liquid pipe 22, and the gas pipe 24, so that each element is integrally provided. Thus, there are no restrictions on the arrangement and dimensions of the expander 12, the condenser 14, and the evaporator 16. In other words, the capillary force Rankine cycle device 10 does not increase restrictions on the arrangement and dimensions of the expander 12, the condenser 14, and the evaporator 16 as compared with a general configuration having an electric pump, for example. . On the other hand, since it is not necessary to provide a pump as described above, the degree of freedom of arrangement and dimensions of each element is improved.

  Thus, in the capillary force utilization Rankine cycle apparatus 10 which concerns on this embodiment, it can operate | move without depending on external energy other than a heat | fever, and the freedom degree of arrangement | positioning and a dimension is high.

(Variation of evaporator)
FIG. 5 shows a schematic plan view of an evaporator 40 according to a first modification. As shown in this figure, the evaporator 40 has an annular capillary structure 42 having a liquid introduction hole 42A at the center instead of the capillary structure 30 formed in a block shape (for example, a columnar shape or a prismatic shape). Is different from the evaporator 16 according to the first embodiment.

  In the annular capillary structure 42, the liquid flows radially from the liquid introduction hole 42 </ b> A that is upstream in the flow direction of the working fluid toward the outer peripheral portion 42 </ b> B (downstream). The heating unit 44 of the evaporator 40 is formed in an annular shape that surrounds the annular capillary structure 42 from the outer peripheral portion 42B side. Therefore, also in the evaporator 40, the capillary structure 42 is heated by the heating unit 44 from the downstream side in the flow direction of the working fluid.

  In place of the evaporator 16, the capillary force-based Rankine cycle device 10 including the evaporator 40 according to the first modification can also obtain the same effect by the same operation as the above-described embodiment.

FIG. 6 shows a schematic plan view of an evaporator 50 according to a second modification. As shown in this figure, the evaporator 50 is common to the evaporator 40 according to the first modification in that it includes an annular capillary structure 52 having a liquid introduction hole 52A at the center, but the capillary structure 52 This differs from the evaporator 40 according to the first modification in that a part of the material on the outer peripheral portion 52B side is different from the material of the remaining portion on the liquid introduction hole 42A side. In addition, the capillary structure 52 according to the second modified example is an independent capillary group that is an assembly of independent (non-communicating) linear tubes, and is a capillary structure 30, 42 that is a porous structure. Is different.

  The portion of the capillary structure 52 on the liquid introduction hole 52A side is constituted by, for example, an aggregate of glass tubes having a minute diameter, and serves as a capillary force acting portion 52C. On the other hand, a part of the capillary structure 52 on the side of the outer peripheral portion 52B is made of, for example, a copper tube assembly having a minute diameter and is a heated portion 52D. That is, the capillary force acting part 52C is made of a material having a relatively low thermal conductivity, and the heated part 52D is made of a material having a sufficiently high thermal conductivity with respect to the capillary force acting part 52C.

  For this reason, the capillary structure 52 is mainly supplied with heat (heat absorption) in the heated part 52D by heating from the heating part 44, and the heat supply (evaporation) in the capillary force acting part 52C is suppressed. It has come to be. In the capillary structure 52, the heated portion 52D has a sufficiently small radial dimension relative to the capillary force acting portion 52C. That is, in the capillary structure 52, the length that the steam flows through the heated portion 52D is kept small.

  Further, in the capillary structure 52, the capillary diameter of the heated part 52D is smaller than the capillary diameter of the capillary force acting part 52C, and the number of capillaries is large (that is, the porosity is large). For this reason, the contact area between the liquid and the heated portion 52D is increased, and the working fluid is efficiently vaporized in the heated portion 52D.

  In place of the evaporator 16, the capillary force utilizing Rankine cycle device 10 including the evaporator 50 according to the second modification can also obtain the same effect by the same operation as the above-described embodiment.

  Further, in the configuration including the evaporator 50 according to the second modified example, the evaporation of the liquid in the capillary force acting unit 52C is suppressed by the heating by the heating unit 44. For example, the portion corresponding to the capillary force acting unit 52C In comparison with the configuration in which liquid evaporation occurs, increase in pressure loss due to liquid vaporization, that is, volume expansion, is suppressed. In other words, the evaporator 50 can set (control) the evaporation site of the liquid in the capillary structure 52 at a desired position according to the setting range of the heated portion 52D. Furthermore, since the heated portion 52D is made of a material having high thermal conductivity, vaporization of the working fluid is promoted, and overheating (superheat) of the working fluid (steam), that is, an increase in vapor pressure is efficiently performed. Can be fulfilled.

  In the second modification, an example in which an independent capillary group is applied to the annular capillary structure 52 is shown, but the capillary structure 30 may be configured as an independent capillary group. In this case, two types of materials having different thermal conductivities may be used similarly to the capillary structure 52, and an independent capillary group may be formed of a single material. Therefore, the capillary structure 52 can be configured as an independent capillary group made of a single material.

  Further, in the second modification, the example in which the material having different thermal conductivity is shown on the upstream side and the downstream side of the capillary structure 52 is shown. However, the present invention is not limited to this, and is made of, for example, a porous body. Alternatively, the thermal conductivity may be different between the downstream side and the upstream side of the capillary structures 30 and 42. In this case, a sintered metal such as copper or copper alloy is used on the downstream side, while a ceramic sintered body, porous glass, or a sintered metal having a relatively low thermal conductivity is used on the upstream side. Can do.

(Application example for automobiles)
FIG. 7 is a schematic system configuration diagram illustrating an example in which the capillary force utilization Rankine cycle device 10 is applied to a thermoelectric power generation system 60 of an automobile. As shown in this figure, a thermoelectric power generation system 60 for an automobile uses heat generated by engine cooling water in order to generate electricity by driving a generator 64 using engine cooling water of an engine 62 that is an internal combustion engine as a heat source. It is applied as a device that converts energy into mechanical energy supplied to the generator 64. As shown in FIG. 8, here, an application example of the capillary force utilization Rankine cycle device 10 provided with the evaporator 50 to the thermoelectric power generation system 60 will be described. However, instead of the evaporator 50, the evaporators 16 and 40 are replaced with each other. Needless to say, it may be used.

  Specifically, as shown in FIG. 7, the evaporator 50 operates in a heating unit 44 that uses high-temperature (approximately 90 ° C.) engine cooling water discharged from the engine 62 as a heat source (high-temperature heat source control). The fluid is evaporated, and the condenser 14 cools the working fluid at the temperature of the low-temperature (approximately 40 [° C.]) engine cooling water (low-temperature heat source) cooled by the heat exchange with the traveling wind Wr by the radiator 66 and condenses. It is supposed to let you. Therefore, the heating unit 44 is configured as a flow path (water jacket 72 described later) that communicates with the cooling water circulation path 65 and exchanges heat with the capillary structure 52, and constitutes the evaporator 50 that is a heat exchanger. is doing.

  The condenser 14 is disposed close to the front or rear side in the vehicle front-rear direction with respect to the radiator 66, and is configured as a forced convection heat exchanger having corrugated fins similarly to the radiator 66. That is, in this application example, the condenser 14 disposed adjacent to the radiator 66 is cooled together with the radiator 66 by the traveling wind Wr, thereby improving the cooling performance.

  The expander 12 is a scroll expander, and converts heat energy into mechanical energy. The generator 64 described above is adopted as the load 26, and the mechanical energy converted by the expander 12 is further converted into electric energy. The AC electrical energy is converted into DC electrical energy by the inverter 68 and stored (charged) in the battery 70. In the case where the generator 64 outputs DC power, a configuration in which the power is directly stored in the battery 70 from the generator 64 may be used.

  In the evaporator 50, the central portion of the bottom wall portion which is the upstream end 28 </ b> A of the shell 28 is connected to the downstream end of the liquid pipe 22 so that the liquid flows into the liquid introduction hole 52 </ b> A of the capillary structure 52. Further, a water jacket 72 for circulating the engine cooling water discharged from the engine 62 is provided on the outer peripheral portion which is the downstream end 28 </ b> B of the shell 28. That is, high-temperature engine coolant is circulated through the water jacket 72 so that the heating unit 44 is configured.

  Further, in the evaporator 50 in this application example, a steam outlet 28 </ b> C is formed at the outer peripheral end portion of the bottom wall portion opposite to the upstream end 28 </ b> A side of the shell 28. A header member 74 is attached to the shell 28 so as to cover the steam outlet 28 </ b> C, and the upstream end of the gas pipe 24 is connected to the header member 74.

  In the capillary power utilization Rankine cycle device 10 constituting the automobile thermoelectric generation system 60 described above, the evaporator 50, the gas pipe 24, and the expander 12 are covered with, for example, a heat insulating material to form a heat insulating structure. Thereby, it is suppressed that the working fluid (part) which became high-pressure gas in the evaporator 50 is condensed in the process of reaching the expander 12. Further, the gas pipe 24 is set (routed) as short as possible so that the air heat of the gas pipe 24 is prevented from escaping.

  Furthermore, in this Rankine-cycle apparatus 10 using capillary force, the piping 20 that connects the expander 12 and the condenser 14 has a heat insulating structure. Thereby, it is suppressed that the low-pressure working fluid (steam) expanded by the expander 12 is condensed before reaching the condenser 14. That is, in the Rankine cycle apparatus 10 using capillary force, the backflow of the working fluid is prevented from occurring due to the condensation of the working fluid at the outlet of the pipe 20.

  Moreover, in this Rankine-cycle apparatus 10 using capillary force, the various materials illustrated, for example in FIG. 4 can be used as a working fluid. The working fluid is sealed and sealed in the Rankine cycle device 10 using the capillary force, for example, after the inside of the Rankine cycle device 10 using the capillary force is evacuated to a high vacuum, the Rankine cycle device 10 using the capillary force is operated in the system. This can be done by injecting a fluid. Moreover, the operating temperature (high temperature heat source temperature, low temperature heat source temperature) of the cycle of the capillary force utilizing Rankine cycle device 10 can be set by adjusting the internal pressure (saturated vapor pressure).

  Next, the operation of the automobile thermoelectric generator system 60 will be described.

  In the automobile thermoelectric generation system 60 configured as described above, when the engine 62 is started and the temperature of the engine cooling water rises, the capillary structure 52 flows from the outer peripheral side with the engine cooling water (heating unit 44) that flows through the water jacket 72. Heated. This heat is transmitted to the heated part 52D mainly made of a material having high thermal conductivity, and the liquid (liquid phase working fluid) in contact with the heated part 52D is evaporated. For this reason, as described above, in the capillary force utilization Rankine cycle device 10, the circulating flow Ff of the working fluid circulating in the circulation path 18 is generated.

  Due to the circulating flow Ff of the working fluid, high-pressure steam generated in the evaporator 50 is supplied to the expander 12 through the gas pipe 24, and the expander 12 is rotationally driven as the steam expands. As a result, the generator 64 that is the load 26 generates electric power as it rotates, and this electric power is stored in the battery 70.

  On the other hand, the low-pressure steam expanded by the expander 12 flows into the condenser 14 through the pipe 20 and is cooled and condensed by exchanging heat with the traveling wind Wr together with the radiator 66. Since the liquid generated by this condensation is continuous with the liquid in the liquid introduction hole 52A of the evaporator 50 through the liquid pipe 22, the capillary of the evaporator 50 is driven by the capillary force in the capillary structure 52 and the driving force by evaporation. The structure 52 is sequentially guided. That is, as described above, the circulating fluid Ff of the working fluid is generated. In the configuration in which the condenser 14 is disposed above the evaporator 50 in the direction of gravity, the difference in height between the condenser 14 and the evaporator 50 is also used for circulating the working fluid.

  As described above, in the thermoelectric power generation system 60 of the automobile, the engine 62 is simply operated, and the circulating fluid Ff of the working fluid is generated in the circulation path 18 of the capillary force utilizing Rankine cycle device 10, and electric power is stored in the battery 70.

  Hereinafter, an evaluation example of the automotive thermoelectric power generation system 60 to which the capillary force utilization Rankine cycle device 10 is applied will be described. Here, as described above, the temperature of the high-temperature heat source is 90 [° C.], the temperature of the low-temperature heat source is 40 [° C.], and the waste heat to the engine cooling water during the 10.15 mode driving (capillary force utilization Rankine cycle device 10 An example in which the amount of heat input) Q is 4 [kW] and ethanol is used as the working fluid will be described. The cycle assumes an ideal cycle and does not consider superheat. As the loss, only the expansion work is taken out, the power is generated, and the pump is pumped. Here, general values of 0.8, 0.95, and 0.6 are used as the expansion efficiency, power generation efficiency, and circulation pump efficiency, respectively.

  When the vapor pressure Pe of the working fluid (ethanol) in the evaporator 50 and the vapor pressure Pc in the condenser 14 are estimated based on the Antoine constant, they are as shown in FIG. From FIG. 9, Pe≈158 [kPa] and Pc≈18 [kPa] can be read.

Further, when the mass flow rate m of the working fluid is calculated based on the heat input amount (4 [kW]) using the Mollier diagram (Ph diagram) shown in FIG. 10, the following is obtained.
m = 4 [kW] / {350-(− 640)} [kJ / kg]
≒ 0.004 [kg / s]

The maximum theoretical work Let that can be taken out by this mass flow rate m is
Let = 0.004 [kg / s] × (350-278) [kJ / kg]
≒ 0.288 [kW]
Therefore, the real work Le considering the expansion efficiency is
Le = 0.8 × 0.288 [kW] ≒ 0.230 [kW]
It becomes.

Furthermore, the actual power generation amount E, taking into account power generation efficiency,
E = 0.95 × 0.230 [kW] ≈0.219 [kW]
It becomes.

Moreover, in order to transport the fluid from the low pressure Pc to the high pressure Pe for the necessary pump work Lp,
Lp = 1 / 0.6 × m × (Pe−Pc) / ρ
It is represented by ρ is the density of ethanol as a working fluid, and when 722 [kg / m ³ ], which is a value at 40 ° C., is used,
Lp = 1 / 0.6 × 0.004 [kg / s]
× (Pe-Pc) [kPa] / ρ [kg / m ³ ]
≒ 1.22 [W]
It becomes.

As described above, the efficiency ηc of the automobile thermoelectric generation system configured by applying the Rankine cycle device including a pump driven by external power separately from the evaporator is
ηc = (E−Lp) / Q
= (0.219-0.00122) [kW] / 4 [kW]
≒ 0.544
It becomes.

In contrast, in the automobile thermoelectric power generation system 60 to which the capillary force utilizing Rankine cycle device 10 is applied, external power is not input to the circulation of the working fluid, so that Lp = 0. Therefore, the efficiency η ₁₀ of the capillary force utilizing Rankine cycle device ₁₀ is
η ₁₀ = (E) / Q = (0.219) [kW] / 4 [kW]
≒ 0.547
It becomes. Thus, in the thermoelectric power generation system 60 of the automobile to which the capillary force utilization Rankine cycle device 10 is applied, it is confirmed that the cycle efficiency is improved as compared with the configuration including the pump driven using external power. It was.

  In order to establish a cycle of the capillary force utilization Rankine cycle device 10 constituting the thermoelectric power generation system 60 using ethanol as the working fluid, the pressure difference (Pe−Pc) is approximately 140 [kPa]. From FIG. 4, it can be seen that a capillary structure 52 having a capillary diameter (pore diameter of the porous body) of approximately 0.6 μm may be used.

  In addition, it can evaluate similarly to said example also about the case where working fluids other than ethanol are used.

  In the application example described above, an example in which engine cooling water on the upstream side with respect to the radiator 66 is used as a high-temperature heat source has been described. However, the present invention is not limited to this, for example, waste heat of transmission, (oil, outer wall of transmission) Etc.), traveling motors (for hybrid vehicles, electric vehicles), engine waste heat (exhaust pipes, oil, engine outer walls, etc.) can be used. The low-temperature heat source may use underfloor traveling wind or the like.

  Furthermore, in the application example described above, an example in which power generation is performed by using waste heat has been described, but the present invention is not limited to this, and can be applied to, for example, transmission use for transmission cooling and lubrication oil pumps.

  Furthermore, in the above-described application examples, application examples to automobiles have been shown. However, the present invention is not limited to this. For example, the present invention can be appropriately applied to Rankine cycle applications using factory waste heat. is there.

It is a system configuration figure of a capillary force utilization Rankine cycle device concerning this embodiment. It is sectional drawing which shows typically the evaporator which comprises the capillary force utilization Rankine cycle apparatus which concerns on this embodiment. It is a schematic diagram for demonstrating the generation | occurrence | production mechanism of the fluid drive force by the evaporator which comprises the capillary force utilization Rankine cycle apparatus which concerns on this embodiment. It is a diagram which shows the relationship between the capillary diameter of the capillary structure which comprises the capillary force utilization Rankine cycle apparatus which concerns on this embodiment, and a pressure | voltage riseable pressure. It is sectional drawing which shows typically the 1st modification of the evaporator which comprises the capillary force utilization Rankine cycle apparatus which concerns on this embodiment. It is sectional drawing which shows typically the 2nd modification of the evaporator which comprises the capillary force utilization Rankine cycle apparatus which concerns on this embodiment. It is a system block diagram which shows the example of application to the electric power generation system of the capillary force utilization Rankine cycle apparatus which concerns on this embodiment. It is sectional drawing which illustrates the specific structure of the evaporator in the example of application to the electric power generation system of the capillary force utilization Rankine cycle apparatus which concerns on this embodiment. It is a diagram which shows the relationship between the temperature and pressure of a working fluid in the example of application to the electric power generation system of the capillary force utilization Rankine cycle apparatus which concerns on this embodiment. It is a Ph diagram of a working fluid in an example of application to a power generation system of a capillary force utilization Rankine cycle device concerning this embodiment.

Explanation of symbols

10 Capillary Force Utilization Rankine Cycle Device 12 Expander (Expansion Element)
14 Condenser (condensing element)
16 Evaporator (evaporation element)
22 Liquid piping
24 Gas pipe (steam pipe)
30 Capillary structure 32 Heating part (heating part)
35 Capillary part 40/50 Evaporator 42/52 Capillary structure 44 Heating part

Claims (3)

An expansion element that expands the supplied gaseous working fluid and converts kinetic energy into external work;
A condensing element for condensing the gas-phase working fluid discharged from the expansion element;
It is configured as an independent capillary group that is an assembly of independent linear pipes that are not in communication with each other, and is provided over the entire surface of the cross section of the working fluid flow path, and the liquid phase working fluid condensed by the condensing element is subjected to capillary force. in the capillary structure for driving, and evaporated comprising pressurized hot section Ru evaporation of the working fluid of the capillary structure in by supplying heat from the downstream end of the flow direction of the working fluid in the capillary structure Elements and
Capillary force utilizing Rankine cycle device. An expansion element that expands the supplied gaseous working fluid and converts kinetic energy into external work;
A condensing element for condensing the gas-phase working fluid discharged from the expansion element;
Operation of the liquid phase configured as a group of independent capillaries that are connected to the condensing element via a liquid pipe and are connected to the expansion element and a vapor pipe and are independent linear tubes. capillary structure for driving the fluid in capillary force, and the pressurized heat Ru evaporation of the working fluid of the capillary structure in by supplying heat from the downstream end of the flow direction of the working fluid in the capillary structure An evaporation element including a portion;
Capillary force utilizing Rankine cycle device. In the capillary structure, a part of the heat supply side by the heating unit is made of a material having a high thermal conductivity with respect to the capillary force acting part constituting the part on the inflow side of the liquid-phase working fluid. The Rankine cycle apparatus using capillary force according to claim 1 or 2, which is a heating unit .

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