JP6727779B2 - Rankine cycle device - Google Patents

Description

The present invention relates to a Rankine cycle device.

BACKGROUND ART Conventionally, a Rankine cycle device is known as a waste heat recovery device that recovers waste heat generated in an engine or the like. For example, the Rankine cycle device described in Patent Document 1 below includes an evaporator that evaporates a liquid-phase working medium by engine waste heat, and an expander that recovers power from a gas-phase working medium that has flowed out of the evaporator. , A condenser for cooling and liquefying the gas-phase working medium flowing out from the expander.

JP, 2014-148910, A

In the Rankine cycle apparatus as described above, for example, in order to downsize the condenser and the like, it is required to suitably cool the gas-phase working medium flowing out from the expander.

An object of the present invention is to provide a Rankine cycle device capable of suitably cooling a gas-phase working medium that has flowed out from an expander.

The Rankine cycle device according to the present invention has a first flow path through which a gas-phase working medium that flows out of an expander and flows into a condenser, and a second flow path through which a liquid-phase working medium that flows out of a condenser flows. A third flow path connected to the first flow path and the second flow path, through which the working medium in the liquid phase flows from the second flow path toward the first flow path, and the first flow path through the third flow path Atomizing means for atomizing at least a part of the liquid-phase working medium flowing into .

In this Rankine cycle device, a part of the liquid-phase working medium flowing through the second flow path is caused to flow into the first flow path through the third flow path, and joins with the gas-phase working medium flowing through the first flow path. Can be made. In the case of merging in this way, heat of the liquid-phase working medium from the working medium of the vapor phase, particularly heat of vaporization when the liquid-phase working medium is vaporized, causes the working medium of the gas phase flowing in the first flow path to Can be cooled. Furthermore, in this Rankine cycle device, at least a part of the liquid-phase working medium flowing into the first flow path is atomized by the atomizing means, so that heat absorption and vaporization of the liquid-phase working medium can be promoted. Therefore, according to this Rankine cycle device, it is possible to preferably cool the gas-phase working medium flowing out from the expander.

Further, the Rankine cycle apparatus according to the present invention further includes a tank portion that is provided in the first flow path on the downstream side of the connection position with the third flow path, and in which the working medium that flows into the condenser flows. , an enlarged portion expanding the flow passage area toward the downstream side, than the enlarged portion is provided on the downstream side, that have a reduced section passage area is reduced toward the downstream side. For this reason,
The working medium that has flowed into the first flow path and is atomized can be diffused by the expansion portion, and heat absorption and vaporization of the liquid-phase working medium can be further promoted. Further, the working medium can be compressed by the contracting section, and the liquefaction of the working medium after the merging can be promoted.

Further, in the Rankine cycle apparatus according to the present invention, a heat radiating member for radiating the working medium may be arranged in the tank portion. According to this Rankine cycle device, the heat of the working medium flowing in the tank portion is radiated by the heat radiating member, and the working medium in the gas phase flowing out from the expander can be cooled more suitably.

ADVANTAGE OF THE INVENTION According to this invention, the Rankine cycle apparatus which can cool the gaseous working medium which flowed out of the expander suitably can be provided.

It is a schematic structure figure of the Rankine cycle device concerning an embodiment. It is a schematic block diagram of the Rankine cycle apparatus of a modification. It is a schematic block diagram of the Rankine cycle apparatus of a modification. (A)-(c) is a figure which shows the example of the cross section in the VV line of FIG. It is a schematic block diagram of the Rankine cycle apparatus of a modification.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings. In the following description, the same or corresponding elements will be denoted by the same reference symbols, without redundant description.

The Rankine cycle device 1 shown in FIG. 1 is mounted in, for example, a vehicle and used to improve fuel efficiency. Examples of vehicles to be mounted include commercial vehicles such as trucks and buses. The vehicle is not particularly limited, and may be, for example, a large vehicle, a medium-sized vehicle, an ordinary passenger vehicle, a small vehicle, or a light vehicle.

The Rankine cycle device 1 uses, for example, the waste heat of the vehicle engine as heat input, converts the heat energy of the waste heat into motive power, and outputs the power. The Rankine cycle apparatus 1 includes a flow path 11, and a pump 21, an evaporator 22, an expander 23, and a condenser 24 are provided on the flow path 11. The working medium M is circulated in the flow path 11. Various materials can be used as the working medium M, and here, R134a which is a low boiling point medium is used.

The pump 21 is provided between the evaporator 22 and the condenser 24, and pumps the working medium M flowing from the condenser 24 to the evaporator 22 side. The evaporator 22 is provided on the downstream side of the pump 21, and heats and evaporates the working medium M compressed by the pump 21. The evaporator 22 heats the working medium M by using, for example, the engine cooling water C as a heat source (heat source on the high temperature side).

The evaporator 22 has, for example, a flow path 26 through which the heat medium L1 flows, and a heat exchanger 27 that is provided on the flow path 26 and exchanges heat between the engine cooling water C and the heat medium L1. .. In the evaporator 22, the working medium M is heated by heat exchange between the heat medium L1 that has absorbed and heated by the heat exchanger 27 and the working medium M flowing in the evaporator 22. The evaporator 22 does not have the flow path 26 and the heat exchanger 27, and has a configuration in which heat is directly exchanged between the engine cooling water C and the working medium M to heat the working medium M. Good. Further, the evaporator 22 may use exhaust heat of the engine or waste heat such as EGR (Exhaust Gas Recirculation) gas as a heat source.

The expander 23 is provided on the downstream side of the evaporator 22. The expander 23 rotates when the working medium M expands, and outputs power. For example, a turbine or the like is used as the expander 23. The expander 23 may output, for example, a mechanical output, or may be connected to, for example, a generator to output an electric output.

The condenser 24 is provided on the downstream side of the expander 23 and cools and condenses the working medium M. The condenser 24 cools the working medium M by using, for example, the traveling wind W when the vehicle travels as a heat source (low temperature side heat source). The condenser 24 includes, for example, a flow passage 28 through which the heat medium L2 flows, and a heat exchanger (sub radiator) 29 provided on the flow passage 28 and exchanging heat between the traveling wind W and the heat medium L2. Have In the condenser 24, the working medium M is cooled by the heat exchange between the heat medium L2 that has been radiated and cooled by the heat exchanger 29 and the working medium M flowing in the condenser 24. Note that the condenser 24 does not have the flow path 28 and the heat exchanger 29, and may directly exchange heat between the traveling wind W and the working medium M to cool the working medium M. Good.

The flow path 11 is composed of, for example, a pipe or the like. The flow path 11 includes a flow path 12 (second flow path) connected to the condenser 24 and the evaporator 22, a flow path 13 connected to the evaporator 22 and the expander 23, an expander 23 and a condenser 24. And a flow path 14 (first flow path) connected to the.

The liquid-phase working medium M flowing out of the condenser 24 and flowing into the evaporator 22 flows through the flow path 12. The pump 21 is provided on the flow path 12. The gas-phase working medium M flowing out of the evaporator 22 and flowing into the expander 23 flows through the flow path 13. The gas-phase working medium M flowing out of the expander 23 and flowing into the condenser 24 flows through the flow path 14. As will be described later, the liquid-phase working medium M may flow through the flow path 14.

The flow channel 11 of the present embodiment is configured to further include a flow channel 15 (third flow channel) connected to the flow channel 12 and the flow channel 14. The flow path 15 branches a part of the liquid-phase working medium M flowing through the flow path 12 into the flow path 14.

One end 15 a of the flow path 15 is connected to the downstream side of the pump 21 in the flow path 12, and the other end 15 b of the flow path 15 is connected to the flow path 14. That is, the flow path 12 is composed of the upstream portion 12a upstream of the connection position with the one end 15a of the flow path 15 and the downstream portion 12b downstream of the connection position. The flow path 14 is composed of an upstream portion 14a upstream of the connection position with the other end 15b of the flow path 15 and a downstream portion 14b downstream of the connection position.

A sprayer (atomization means) 31 for atomizing at least a part of the liquid-phase working medium M flowing into the channel 14 through the channel 15 is provided at the other end 15b of the channel 15. The sprayer 31 disperses the liquid-phase working medium M in the flow path 14 as droplets. The atomizer 31 atomizes at least a part of the liquid-phase working medium M, and ejects the atomized working medium M into the flow path 14, for example.

As described above, in the Rankine cycle device 1, a part of the liquid-phase working medium M flowing in the flow channel 12 is caused to flow into the flow channel 14 via the flow channel 15 and joins with the gas-phase working medium M flowing in the flow channel 14. Can be made. In the case of merging in this way, the operation of the gas phase flowing through the flow path 14 is caused by the heat absorption from the gas-phase working medium M by the liquid-phase working medium M, particularly the heat of vaporization when the liquid-phase working medium M is vaporized. The medium M can be cooled.

Further, in the Rankine cycle device 1, since at least a part of the liquid-phase working medium M flowing into the flow path 14 is atomized by the sprayer 31, heat absorption and vaporization of the liquid-phase working medium M can be promoted. Therefore, according to the Rankine cycle device 1, it is possible to preferably cool the gas-phase working medium M flowing out from the expander 23. As a result, the temperature of the working medium M flowing into the condenser 24 (inlet temperature T1) can be lowered, so that the cooling performance required for the condenser 24 can be relaxed and the condenser 24 can be downsized. It becomes possible. Further, as the material of the condenser 24 (particularly, the heat exchanger), a material that does not have excellent high temperature characteristics can be used, so that the degree of freedom in selecting the material can be increased.

The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments.

FIG. 2 is a schematic configuration diagram of a modified Rankine cycle device 1A. As shown in FIG. 2, the Rankine cycle apparatus 1B of the modified example is different from the Rankine cycle apparatus 1 of the above embodiment in that a valve (flow rate adjusting unit) 33 is provided on the flow path 15. The valve 33 adjusts the flow rate of the working medium M flowing through the flow path 15 by changing its opening. When the valve 33 is opened, a part of the liquid-phase working medium M flowing in the flow channel 12 flows into the flow channel 14 via the flow channel 15, and the gas-phase working medium M flowing in the flow channel 14 is cooled. Will be done.

The Rankine cycle apparatus 1A of the modified example can also favorably cool the vapor-phase working medium M flowing out from the expander 23, as in the above embodiment. Further, since the flow rate of the working medium M flowing through the flow path 15 can be adjusted, the working medium M in the gas phase flowing out from the expander 23 can be cooled more preferably.

FIG. 3 is a schematic configuration diagram of a Rankine cycle device 1B of a modified example, and FIGS. 4A to 4C are diagrams showing an example of a cross section taken along line IV-IV of FIG. As shown in FIG. 3, the Rankine cycle device 1</b>B of the modified example is different from the Rankine cycle device 1 of the above embodiment in that the tank unit 60 is provided. The tank portion 60 is provided in the downstream portion 14b of the flow passage 14, that is, in the flow passage 14 downstream of the connection position with the flow passage 15.

The tank portion 60 includes an enlarged portion 61 whose flow passage area increases toward the downstream side, a main body portion 62 which is provided on the downstream side of the enlarged portion 61 and has the same cross-sectional shape in the direction along the flow passage, and a main body. And a reduction portion 63 which is provided on the downstream side of the portion 62 and whose flow passage area is reduced toward the downstream side. In the expansion section 61, the flow path area is expanded by increasing the flow path diameter, and in the reduction section 63, the flow path area is decreased by decreasing the flow path diameter.

As shown in FIG. 4, a heat dissipation member 64 that dissipates heat from the working medium M is disposed in the tank portion 60. The heat dissipation member 64 contacts the working medium M flowing in the tank portion 60 and transfers the heat of the working medium M to the outside of the tank portion 60. The heat dissipation member 64 here is arranged over the enlarged portion 61, the main body portion 62, and the reduced portion 63. The heat dissipation member 64 may be a fin 64A having a fin shape as in the example of FIG. 4A, or a porous member 64B formed of a porous material as in the example of FIG. 4B. It may be present, or may be a laminated mesh member 64C in which mesh layers are laminated in the flow direction as shown in FIG. 4(c). The heat dissipation member 64 may be formed of a material having higher thermal conductivity than the material forming the tank portion 60. Further, the heat dissipation member 64 has only to be arranged in at least a part of the enlarged portion 61, the body portion 62, and the reduced portion 63, and may be arranged only in the body portion 62, for example.

The Rankine cycle apparatus 1B of the modified example can also suitably cool the vapor-phase working medium M flowing out from the expander 23, as in the above embodiment. Further, in the Rankine cycle apparatus 1B of the modified example, the working medium M that has flowed into the flow path 14 and has been atomized can be diffused by the expansion portion 61, and heat absorption and vaporization of the liquid-phase working medium M can be further promoted. Further, by compressing and pressurizing the working medium M by the reduction unit 63, the liquefaction of the working medium M after the merging can be promoted. Further, in the Rankine cycle apparatus 1B of the modified example, the heat of the working medium M flowing in the tank portion 60 is radiated by the heat radiating member 64, and the working medium M in the gas phase flowing out from the expander 23 can be cooled more preferably. It will be possible.

FIG. 5: is a schematic block diagram of Rankine cycle apparatus 1C of a modification. As shown in FIG. 5, the Rankine cycle apparatus 1C of the modified example is different from the Rankine cycle apparatus 1B of the above-described embodiment in that the tank section 60 is provided. The Rankine cycle apparatus 1C of the modified example can also favorably cool the vapor-phase working medium M flowing out from the expander 23, as in the Rankine cycle apparatus 1B of the above embodiment. In addition, since the flow rate of the working medium M flowing through the flow path 15 can be adjusted as in the Rankine cycle apparatus 1A of the above-described embodiment, the gas-phase working medium M flowing out from the expander 23 can be cooled more preferably. Becomes

The atomizer 31 of the above-mentioned embodiment only needs to atomize at least a part of the liquid-phase working medium M flowing into the flow path 14, for example, the entire amount thereof may be atomized, or a part thereof may be atomized. You may make it. The atomizing means is not limited to the atomizer 31.

1, 1A... Rankine cycle device, 12... Flow path (second flow path), 14... Flow path (first flow path), 15... Flow path (third flow path), 21... Pump, 23... Expander, 24... Condenser, 31... Atomizer (atomization means), 33... Valve (flow rate adjusting part), 60... Tank part, 61... Enlargement part, 63... Reduction part, 64... Heat dissipation member, M... Working medium.

Claims (2)

A first flow path through which the working medium in the gas phase flows out of the expander and flows into the condenser;
A second flow path through which the working medium in a liquid phase flowing out from the condenser flows;
A third flow path connected to the first flow path and the second flow path, in which the working medium in a liquid phase flows from the second flow path toward the first flow path;
Atomizing means for atomizing at least a part of the working medium in the liquid phase flowing into the first channel through the third channel,
A tank portion that is provided on the downstream side of a connection position with the third flow path in the first flow path, and in which the working medium flowing into the condenser flows.
The tank section is
An enlarged portion in which the flow passage area increases toward the downstream side,
A reducing portion that is provided on the downstream side of the expanding portion and has a flow channel area that decreases toward the downstream side.
Rankine cycle equipment. The Rankine cycle device according to claim 1, wherein a heat dissipation member that dissipates the working medium is disposed in the tank portion.

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