JP2016056785A - Vehicular waste heat recovery device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicular waste heat device having an improved heat efficiency of a rankine cycle.SOLUTION: A vehicular waste heat recovery device 1 includes rankine cycle 3 having a cooling medium pump 4 circulating a working fluid, a heater 5 heating the working fluid with waste heat from an engine of a vehicle, an expander 6 expanding the working fluid to generate an output, and rankine condenser 7A, 7B condensing the working fluid. The rankine condenser 7A, 7B is provided on a roof of the vehicle. A cooling medium pump 4 is provided on the roof along with the rankine condenser 7A, 7B.SELECTED DRAWING: Figure 1

Description

The present invention relates to a vehicle waste heat recovery device using a Rankine cycle.

As a conventional technique, a waste heat recovery apparatus for a vehicle disclosed in Japanese Patent Application Laid-Open No. 2012-184697 is known. In order to improve the thermal efficiency of the Rankine cycle, this waste heat device for vehicles has a Rankine condenser that condenses the working fluid in the Rankine cycle and is placed in the roof top room on the roof of the truck. Inside, the running wind flows into the rooftop room through a gap and hits the Rankine condenser, so that the heat dissipation of the Rankine condenser is improved.
On the other hand, in the Rankine cycle, the pump that pumps the working fluid, the heat exchanger that heats the working fluid pumped by the pump by the waste heat of the engine of the vehicle, and the working fluid that is heated and vaporized by the heat exchanger are expanded. The expander that recovers mechanical energy is disposed in the engine room.

JP2012-184597

  In such a conventional technology, the Rankine condenser is arranged in the roof room on the roof of the truck, and the pump is arranged in the engine room. Therefore, the Rankine condenser outlet side and the pump inlet side are arranged. The pipe that connects is passed through the engine room in a high temperature atmosphere. Moreover, since the Rankine condenser and the pump are arranged apart from each other, the piping becomes long. Therefore, the supercooled working fluid that has been supercooled by the Rankine condenser disappears in the process of flowing through the piping connecting the outlet side of the Rankine condenser and the inlet side of the pump, making it impossible to operate Rankine in the Rankine cycle. There was a problem that it might become.

  This invention solves such a problem and provides the waste heat apparatus for vehicles which improved the thermal efficiency of Rankine cycle.

In order to achieve the above object, the invention of claim 1 includes a refrigerant pump for circulating a working fluid, a heater for heating the working fluid sent by the refrigerant pump by waste heat of a vehicle engine, A Rankine cycle having an expander that expands the working fluid heated and vaporized by the heater to generate an output, and a Rankine condenser that condenses the working fluid expanded by the expander; The condenser is a vehicle waste heat recovery apparatus disposed on a roof of the vehicle, and the refrigerant pump is a vehicle waste heat recovery apparatus disposed on the roof of the vehicle together with the Rankine condenser.

The invention of claim 2 is the waste heat recovery apparatus for vehicles according to the invention of claim 1, wherein the refrigerant pump is disposed on the leeward side of the Rankine condenser.

The Rankine condenser according to a third aspect of the present invention is the Rankine condenser, wherein the inlet of the working fluid flowing in from the expander is located on the upper side of the Rankine condenser. An outlet through which the working fluid in the condenser flows out is disposed on the lower side, and the working fluid flows in the Rankine condenser from the upper side to the lower side, and the refrigerant pump is the Rankine condenser It is the waste heat recovery device for vehicles arrange | positioned at the lower part side.

The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein the expander is disposed on a roof of the vehicle, and the Rankine condenser, the refrigerant pump, The expander is a waste heat recovery device for a vehicle arranged as a unit on the roof of the vehicle.

The invention according to claim 5 is the vehicle waste heat recovery apparatus according to any one of claims 1 to 4, wherein the Rankine condenser is provided with a cooling fan. .

According to the invention of claim 1, since the refrigerant pump is a waste heat recovery device for vehicles arranged on the roof of the vehicle together with the Rankine condenser, the working fluid supercooled by the Rankine condenser is: Since the supercooled state can be maintained in the process of flowing through the piping connecting the outlet side of the Rankine condenser and the inlet side of the pump, there is an advantage that the thermal efficiency of the Rankine cycle can be improved.

According to the invention of claim 2, since the refrigerant pump is a vehicle waste heat recovery device disposed on the leeward side of the Rankine condenser, the refrigerant pump is located on the upstream side of the Rankine condenser. Compared with the case where it is arranged, since it is possible to prevent a reduction in the amount of air passing through the Rankine condenser, there is an advantage that a reduction in the condensation capacity of the Rankine condenser can be prevented.

According to the invention of claim 3, since the refrigerant pump is a vehicle waste heat recovery device disposed on the Rankine condenser lower side, the refrigerant pump is downstream in the flow direction of the working fluid of the Rankine condenser. As compared with the case where the refrigerant pump is arranged upstream in the flow direction of the working fluid of the Rankine condenser, the cooling effect of the refrigerant pump by the air passing through the Rankine condenser is compared with the case where the refrigerant pump is arranged upstream of the Rankine condenser. There is an advantage that it goes up.

According to the invention of claim 4, the expander is disposed on the roof of the vehicle, and the Rankine condenser, the refrigerant pump, and the expander are disposed as one unit on the roof of the vehicle. Since it is a waste heat recovery device for vehicles, there is an advantage that attachment becomes easy when the Rankine condenser, the refrigerant pump, and the expander are arranged on the roof of the vehicle.

According to the invention of claim 5, since the Rankine condenser is a vehicle waste heat recovery device in which a cooling fan is provided, the operation of passing through the Rankine condenser even when the vehicle is stopped. Since the fluid can be condensed by the cooling fan, there is an advantage that the Rankine cycle can be operated.

The block diagram of the waste heat recovery device for vehicles which is a present Example Side view of a vehicle equipped with a vehicle waste heat recovery device according to this embodiment mounted on a roof The perspective view which shows the unit structure of the waste heat recovery apparatus for vehicles which is a present Example. The block diagram which shows arrangement | positioning of the condenser for Rankine of the waste heat recovery apparatus for vehicles which is a present Example Open / close valve operation flow diagram of the vehicle waste heat recovery apparatus of this embodiment

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of a vehicle waste heat recovery apparatus according to the present embodiment. FIG. 2 is a cross-sectional view showing the configuration of the vehicle waste heat recovery apparatus according to the present embodiment on the vehicle. FIG. 3 is a perspective view showing a unit on which a part of the vehicle waste heat recovery apparatus according to this embodiment is mounted. FIG. 4 is a configuration diagram showing the arrangement of Rankine condensers in the vehicle waste heat recovery apparatus according to this embodiment. FIG. 5 shows a flow chart of the on-off valve operation provided in the Rankine condenser of the waste heat recovery apparatus for a vehicle according to this embodiment.

FIG. 1 shows a configuration of a vehicle waste heat recovery apparatus 1 according to an embodiment of the present invention. An engine 2 mounted on a vehicle 30 and a Rankine cycle 3 for converting waste heat of the engine 2 into electric power and recovering it. A refrigeration cycle 20 used for air conditioning of a vehicle is provided.

The engine 2 is a water-cooled engine and is cooled by cooling water circulating in the cooling water circulation path by a circulation pump (not shown). A heater 5 of the Rankine cycle 3 to be described later is connected to the cooling water circulation path, and the cooling water which has become high temperature by cooling the engine 2 exchanges heat with the working fluid circulating in the Rankine cycle. As a result, engine waste heat is recovered.

Rankine cycle 3 is a so-called power regeneration Rankine cycle that recovers waste heat of engine 2 by converting it into electric power, and is sent by refrigerant pump 4 that circulates the working fluid that circulates in the circulation path, and refrigerant pump 4. A heater 5 that heats the working fluid that has been heated by the waste heat of the engine 2 of the vehicle 30, an expander 6 that generates an output by expanding the working fluid that has been heated by the heater 5 to high temperature and pressure, and an expander Rankine condensers 7A and 7B for condensing the working fluid expanded by 6, receiver 8 for storing the working fluid condensed by Rankine condensers 7A and 7B, and condensed working fluid from receiver 8 It is composed of a working fluid circuit having a subcooler 9 for providing supercooling.

  The refrigerant pump 4 is driven by the electric motor 11 and pumps the supercooled working fluid sent from the subcooler 9 to the heater 5. In the heater 5, the cooling water circulation path and the working fluid circulation path are connected, and the cooling water in the cooling water circulation path that has become high temperature by cooling the engine 2 and the working fluid in the working fluid circulation path sent from the refrigerant pump 4. Is a heat exchanger that exchanges heat in the heater 5 to bring the working fluid into a high temperature and high pressure superheated state.

The expander 6 expands the superheated working fluid sent from the heater 5 and converts it into mechanical energy. A power generator 12 is connected to the expander 6, and mechanical energy obtained by the expander 6 is converted into electric power and stored in a battery (not shown). The Rankine condensers 7A and 7B are heat exchangers that condense (liquefy) the working fluid by exchanging heat between the working fluid expanded by the expander 6 and the outside air.

The refrigeration cycle 20 is composed of a compressor 21, a condenser 22 for a refrigeration circuit, an expansion valve 23, an evaporator 24, and a refrigerant circulation path connecting them. The refrigerant condensed and condensed by the circuit condenser 22 is decompressed and expanded by the expansion valve 23, the decompressed and expanded refrigerant is evaporated by the evaporator 24, the evaporated refrigerant is sent to the compressor 21, and again the compressor It is compressed by 21 and circulates in the refrigerant circuit. The compressor 21 is driven by the power of the engine 2 via the transmission belt 25. The evaporator 24 cools the air sent into the vehicle 30 by absorbing heat from the air sent into the vehicle 30. The refrigeration circuit condenser 22 is provided with a fan (not shown) and is disposed in the engine room 31 of the vehicle 30. In the process of circulating the refrigerant that has become high temperature and high pressure by the compressor 21 through the refrigeration circuit condenser 22. Condensate by running wind or fan blow.

As shown in FIG. 2, the refrigerant pump 4, the expander 6, the Rankine condensers 7 </ b> A and 7 </ b> B, the receiver 8, and the subcooler 9 of the Rankine cycle 3 are arranged on the roof 32 of the vehicle 30.
On the other hand, as shown in FIG. 1, the heater 5 of the Rankine cycle 3 exchanges heat between the coolant that has become high temperature by cooling the engine 2 and the working fluid that circulates in the Rankine cycle 3. Is placed inside.

Details of the arrangement of the refrigerant pump 4, the expander 6, the Rankine condensers 7A and 7B, the receiver 8, and the subcooler 9 in the Rankine cycle 3 are shown in FIG. A frame structure in which the refrigerant pump 4, the expander 6, the Rankine condensers 7 </ b> A and 7 </ b> B, the receiver 8, and the subcooler 9 of the Rankine cycle 3 are substantially L-shaped in a side view and include a vertical surface portion 34 and a bottom surface portion 35. The base member 33 is disposed on the roof 32 of the vehicle 30 so that the vertical surface portion 34 is on the front side in the front-rear direction of the vehicle 30.

On the vertical surface portion 34 of the base member 33, two Rankine condensers 7A and 7B are arranged side by side in the width direction of the vehicle 30, and the Rankine condenser 7A ( Hereinafter, the subcooler 9 is disposed integrally with the right Rankine condenser 7A below the right Rankine condenser. Two cooling fans 10A and 10B are arranged in a horizontal arrangement on the back side of the right Rankine condenser 7A and the subcooler 9. The Rankine condenser 7B (hereinafter referred to as the left Rankine condenser) disposed on the left side when viewed from the front side is not provided with a cooling fan. As shown in FIG. 5, the cooling fans 10A and 10B are driven when the speed of the vehicle is equal to or lower than a predetermined speed (including when the vehicle is stopped; the same applies hereinafter), and stopped when the speed is higher than the predetermined speed. Take control. Therefore, when the vehicle 30 is traveling, the two Rankine condensers 7A and 7B receive the traveling wind, and when the traveling speed of the vehicle 30 is lower than the predetermined speed and sufficient traveling wind is not generated, the left Rankine condensation is performed. The vessel 7B is not blown by the traveling wind, but the right Rankine condenser 7A and the subcooler 9 can be blown by the cooling fans 10A and 10B. Therefore, even if the vehicle 30 is below the predetermined speed and sufficient traveling wind is not generated, the working fluid flowing in the right Rankine condenser 7A dissipates heat by the cooling fans 10A and 10B. Cycle 3 can be operated.

Each Rankine condenser 7A, 7B is a multi-flow type condenser in which tubes are arranged in a horizontal direction between headers on the left and right ends (not shown). The Rankine condensers 7A, 7B In the header upper part, inflow ports 41A and 41B into which the working fluid sent from the expander flows are provided. The header lower part on the left side in the front view of the right Rankine condenser 7A and the right side in the front view of the left Rankine condenser 7B. Outlet 42A, 42B from which the working fluid which flowed in each Rankine condenser flows out is provided in the lower part of the header.

The expander 6 and Rankine condensers 7A and 7B are connected by piping constituting the working fluid circulation path, and the piping branches immediately before the Rankine condensers 7A and 7B. The branched piping is the right Rankine. The inlet 41A of the condenser 7A and the inlet 41B of the left Rankine condenser 7B are respectively connected. Further, an open / close valve 45 is provided in the pipe connected to the inlet 41B of the left Rankine condenser 7B. Also, the pipes connected to the outlets 42A and 42B of the Rankine condensers 7A and 7B merge just before the receiver 8 and connect to an inlet provided on the bottom surface of the receiver 8, and are provided on the bottom surface of the receiver 8. The pipe connected to the outlet is connected to one end side of the subcooler 9, and the pipe connected to the other end side of the subcooler 9 is connected to the refrigerant pump 4.
Accordingly, the working fluid that has flowed into the Rankine condensers 7A and 7B dissipates heat while flowing from the upper side to the lower side of the Rankine condensers 7A and 7B by running wind or by the cooling fans 10A and 10B. In the course of flowing through the subcooler 9 via the receiver 8, the refrigerant is supercooled and sent to the refrigerant pump 4. Therefore, the working fluid flowing through the Rankine condensers 7A and 7B and the subcooler 9 is cooled on the lower side rather than on the upper side. In this embodiment, the on-off valve 45 is provided in the pipe connected to the inlet 41B of the left Rankine condenser 7B. However, the pipe is connected to the outlet 42B of the Rankine condenser 7B. The on-off valve 45 may be provided up to the junction with the pipe connected to the outlet 42A of the condenser 7A.

  The receiver 8 has a vertically long structure, and the receiver 8, the refrigerant pump 4, and the electric motor 11 are fixed to the bottom surface portion 34 of the base member 32 via a bracket on the back side of the right Rankine condenser 7A. That is, since the receiver 8, the refrigerant pump 4, and the electric motor 11 are disposed on the leeward side of the right Rankine condenser 7A and the subcooler 9, the front side of the right Rankine condenser 7A blocks the traveling wind. Therefore, effective heat dissipation in the right Rankine condenser 7A becomes possible. Since the lower part of the receiver 8 where the working fluid is accumulated and the refrigerant pump 4 are disposed on the lower side of the right Rankine condenser 7A, the traveling wind that has passed through the lower side of the right Rankine condenser 7A and the subcooler 9 is provided. Alternatively, since the air blown by the cooling fans 10A and 10B hits the lower part where the working fluid of the receiver 8 accumulates and the refrigerant pump 4, the traveling wind passing through the upper side of the right Rankine condenser 7A or the air blown by the cooling fans 10A and 10B The air blows at a lower temperature. Therefore, there is a possibility that the supercooling is lost in the process in which the working fluid supercooled by the subcooler 9 is sent to the refrigerant pump 4, when the refrigerant pump 4 is arranged in the engine room, or in the right Rankine condenser 7A. Compared with the case where the refrigerant pump 4 and the receiver 8 are arranged on the upper side, there is an advantage that the thermal efficiency of the Rankine cycle 3 can be improved.

  Further, the receiver 8 and the refrigerant pump 4 are disposed on the back side of the right Rankine condenser 7A, that is, on the leeward side of the right Rankine condenser 7A provided with the cooling fans 10A and 10B. Since the receiver 8 and the refrigerant pump 4 can be cooled by the air blown by the cooling fans 10A and 10B even if the speed of the air is below the predetermined speed and sufficient traveling wind is not generated, the operation is overcooled by the subcooler 9. The possibility that the supercooling is lost in the process in which the fluid is sent to the refrigerant pump 4 is less than when the receiver 8 and the refrigerant pump 4 are arranged on the back side of the left Rankine condenser 7B without a cooling fan. Therefore, there is an advantage that the thermal efficiency of the Rankine cycle 3 can be improved.

Further, in this embodiment, the piping branches immediately before the left and right Rankine condensers 7A and 7B, and the piping merges immediately after the left and right Rankine condensers 7A and 7B, respectively. Since the devices 7A and 7B are arranged in parallel, there is an effect that the pressure loss of the working fluid is reduced as compared with the case where the Rankine condensers are arranged in series.

In this embodiment, the opening / closing valve 45 is provided in the pipe connected to the left Rankine condenser 7B not provided with the blower fan, but the opening / closing valve 45 is not necessarily provided. Even if the opening / closing valve 45 is not provided, when the speed of the vehicle 30 is equal to or lower than the predetermined speed and sufficient traveling wind is not generated and the blowing fans 10A and 10B are operating, the blowing fans 10A and 10B are provided. In the right Rankine condenser 7A, since the working fluid is condensed by the blowing fans 10A and 10B, the pressure of the working fluid in the right Rankine condenser 7A is reduced by the pressure of the working fluid in the left Rankine condenser 7B. This is because the working fluid flows into the right Rankine condenser 7A side where the blower fans 10A and 10B are provided because the pressure is lower than the pressure.
Further, as in this embodiment, an opening / closing valve 45 is provided in a pipe connected to the left Rankine condenser 7B not provided with a blower fan, and the speed of the vehicle 30 is predetermined as in the control flow shown in FIG. If the running air is not generated at a speed lower than the speed and the blower fans 10A and 10B are operating (including the case where the vehicle 30 is stopped), the control of closing the on-off valve 45 is performed. Since the working fluid can flow only through the right Rankine condenser 7A provided with the blower fans 10A and 10B, the operation of the Rankine cycle 3 can be stabilized. In this embodiment, the driving control of the blower fans 10A and 10B and the opening / closing control of the on-off valve 45 are performed based on the speed of the vehicle, but a wind speed sensor for detecting the traveling wind passing through the Rankine condenser is provided. When the wind speed is equal to or lower than the predetermined speed, the blower fans 10A and 10B may be driven to perform control to close the on-off valve 45.

Further, the refrigerant pump 4, the electric motor 11, the expander 6, the generator 12, the Rankine condensers 7A and 7B, the receiver 8, and the subcooler 9 in the Rankine cycle 3 in this embodiment are substantially L-shaped in side view. Since the unit structure is arranged on the base member 33 having a frame structure composed of the vertical surface portion 34 and the bottom surface portion 35, the refrigerant pump 4, the electric motor 11, the expander 6, the generator 12, and the Rankine condensation The installation of the devices 7A, 7B, the receiver 8, and the subcooler 9 on the roof 31 of the vehicle 30 has an advantage that the operation is simpler than the case where each of them is individually installed on the roof 31 of the vehicle 30. .
In the Rankine cycle 3 of this embodiment, the receiver 8 and the subcooler 9 are provided. However, the receiver 8 can be omitted, and the subcooler 9 is omitted by providing the Rankine condenser with a subcooler. It is also possible to do.
In the Rankine cycle 3 of this embodiment, the right Rankine condenser 7A is provided with the two blower fans 10A and 10B, but may be one or three or more.

1 Vehicle waste heat recovery device, 2 engine, 3 Rankine cycle, 4 refrigerant pump,
5 Heater, 6 Expander, 7A, 7B Condenser for Rankine, 10A, 10B Cooling fan,
30 vehicle, 32 vehicle roof, 33 base member

Claims (5)

A refrigerant pump that circulates the working fluid, a heater that heats the working fluid sent by the refrigerant pump by waste heat of a vehicle engine, and an output that is expanded by heating and vaporizing the working fluid heated by the heater. A Rankine cycle having a generated expander and a Rankine condenser for condensing the working fluid expanded by the expander;
The Rankine condenser is disposed on the roof of the vehicle, and the refrigerant pump is disposed on the roof of the vehicle together with the Rankine condenser. . The waste heat recovery apparatus for a vehicle according to claim 1, wherein the refrigerant pump is disposed on the leeward side of the Rankine condenser. The Rankine condenser is configured such that the inlet of the working fluid flowing in from the expander is disposed on the upper side of the Rankine condenser, and the outlet of the working fluid in the Rankine condenser is disposed on the lower side. 3. The condenser according to claim 2, wherein the working fluid is a condenser that flows from an upper side to a lower side in a Rankine condenser, and the refrigerant pump is disposed on a lower side of the Rankine condenser. Waste heat recovery equipment for vehicles. The expander is arranged on a roof of the vehicle, and the Rankine condenser, the refrigerant pump, and the expander are arranged as a unit on the roof of the vehicle. The vehicle waste heat recovery apparatus according to any one of 1 to 3. The vehicle waste heat recovery apparatus according to any one of claims 1 to 4, wherein the Rankine condenser is provided with a cooling fan.

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