CN108343495A - Exhaust gas heat recovery device - Google Patents

Abstract

Present invention offer can improve recycling heat and shorten preheating time and can expand the exhaust gas heat recovering instrument of interior space.Exhaust gas heat recovery device has：Engine (1) at least has oil sump (2)；Exhaust pipe (5₁、5₂), it is used to be discharged the gas of engine (1) discharge；Catalyst converter (6), part of it or all set on the vehicle front of engine (1) purify discharge gas；And heat exchange medium, there is above-mentioned exhaust gas heat recovery device the exhaust gas heat recovering instrument (7) that heat exchange is carried out between above-mentioned heat exchange medium and discharge gas, above-mentioned exhaust gas heat recovering instrument (7) to be set to the exhaust pipe (5 in the downstream side of catalyst converter (6)₂) midway, and a part for above-mentioned exhaust gas heat recovering instrument (7) at least be set to above-mentioned oil sump (2) bottom lower section.

Description

Exhaust Heat Recovery Device

technical field

The present invention relates to an exhaust heat recovery device for transferring heat in exhaust gas of a vehicle engine to an engine heat exchange medium.

Background technique

Patent Document 1 discloses a structure in which an exhaust heat recovery device is arranged inside a floor tunnel.

prior art literature

patent documents

Patent Document 1: JP-A-2016-121557

Contents of the invention

The problem to be solved by the invention

However, the exhaust heat recovery device described in Patent Document 1 is arranged inside the floor tunnel. Therefore, in a front-engine vehicle, the exhaust gas flow path becomes longer and the temperature of the exhaust gas flowing into the exhaust heat recovery device decreases. The amount of heat is reduced, and it is difficult to sufficiently shorten the warm-up time.

In addition, since the flow path of the heat exchange medium becomes longer, the weight of the heat exchange medium increases, the temperature rise of the cooling water tends to be delayed, and it is difficult to sufficiently shorten the warm-up time.

In addition, the heat dissipation area of the cooling water flow path is large, so the heat recovered by the cooling water is easily released to the atmosphere before being used for preheating, and it is difficult to sufficiently shorten the preheating time.

In addition, since the exhaust heat recovery device is arranged inside the floor tunnel, the space in the car will be squeezed.

The present invention solves the above-mentioned problems, and an object of the present invention is to provide an exhaust heat recovery device capable of shortening the warm-up time and expanding the interior space of the vehicle.

solutions to problems

In order to solve the above problems, the exhaust heat recovery device of the present invention includes: an engine, which has at least an oil pan; an exhaust pipe, which is used to discharge the gas exhausted by the engine; , to purify the exhaust gas; and a heat exchange medium, the exhaust heat recovery device has an exhaust heat recovery device for exchanging heat between the heat exchange medium and the exhaust gas, and in the above exhaust heat recovery device, the exhaust The gas heat recovery device is provided in the middle of the exhaust pipe on the downstream side of the catalyst, and a part of the exhaust heat recovery device is provided at least below the bottom of the oil pan.

Invention effect

As the temperature of the exhaust gas increases, the amount of heat exchange medium retained decreases, and the heat dissipation area of the heat exchange medium flow path decreases, so the warm-up time can be shortened, and the interior space of the vehicle can be expanded.

Description of drawings

FIG. 1 is a perspective view of a vehicle below an engine viewed obliquely from the lower side.

Fig. 2 is a perspective view of the exhaust heat recovery unit and radiator viewed from the front of the vehicle.

Fig. 3 is a conceptual diagram of the exhaust heat recovery device viewed from the right side of the vehicle.

Fig. 4 is a conceptual diagram of the exhaust heat recovery device viewed from the side of the engine.

Fig. 5 is a bottom view of the exhaust heat recovery device viewed from the lower side of the engine.

Fig. 6 is a conceptual diagram of the exhaust heat recovery device viewed from the front of the vehicle.

Fig. 7 is an enlarged plan view of the exhaust heat recovery device viewed from above.

Fig. 8 is a conceptual cross-sectional view of the exhaust heat recovery device viewed from the side.

(a) of FIG. 9 is a conceptual sectional view taken along line AA of FIG. 8 . (b) is a modified example of (a). (c) is another modified example of (a).

Fig. 10 is a block diagram showing an engine provided with an exhaust heat recovery device and a flow of a heat exchange medium.

Explanation of reference signs

1 engine

2 oil pan

3 flywheel

4 Radiators

41 Radiator outlet pipe

42 Inlet pipe

5 ₁ , 5 ₂ exhaust pipe

6 Catalyst housing

7 Exhaust heat recovery device

7a Outer cylinder

7b Inner cylinder

8 suspension frame

10 heater

11 water pump

70 Recycler body

71 Exhaust gas flow path

71A Second flow path

72, 72 ₂ heat exchange medium passages

72A First flow path

73 heat transfer fins

74 input tube

75 output tube

76 Drain water piping

Detailed ways

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings shown in FIGS. 1 to 10 .

1 to 6 show an engine and an exhaust heat recovery device installed around it. 1 is a view looking up at the lower part of the engine 1 from the side, and an oil pan 2 is provided at the bottom. 3 is a flywheel provided on the side of the engine 1 . The front of the engine 1 is provided with a radiator 4 that delivers the heat exchange medium to the engine 1, and the rear of the radiator 4 is provided with an exhaust pipe _{5 1 for} delivering the exhaust gas of the engine 1. There is a housing 6 in which the catalytic converter is housed. Downstream of the catalytic converter housing 6, a tubular exhaust heat recovery device 7 is provided from the front of the vehicle toward the rear, and the downstream of the exhaust heat recovery device 7 is connected to an exhaust pipe _{5 2 .} A muffler (not shown) is also connected downstream. The exhaust pipe ₅₂ is arranged so as to pass above the suspension frame 8 and is formed by bending in an inverted U shape above the suspension frame 8 .

The suspension frame 8 is disposed behind the engine 1 , and left and right wheels are provided on the left and right sides of the suspension frame 8 via suspension devices (not shown).

The exhaust heat recovery device 7 is disposed close to the lower side of the oil pan 2 so as to pass through the bottom 2 a of the oil pan 2 in the front-rear direction of the vehicle body, and is disposed so as to efficiently radiate exhaust gas to the oil pan 2 . hot. The left and right sides of the bottom surface side of the oil pan 2 are formed as recesses 2b, and the exhaust heat recovery device 7 is arranged at a position passing through the recesses 2b. The exhaust heat recovery device 7 is disposed above a plane including the lower end of the suspension frame 8 , that is, a horizontal plane H extending from the lower surface of the suspension frame 8 (see FIG. 4 ).

As shown in FIG. 8 , the exhaust heat recovery unit 7 is composed of an outer cylinder 7 a including a tubular recovery unit body 70 and an inner cylinder 7 b arranged concentrically inside the outer cylinder 7 a. The recoverer main body 70 is arranged substantially horizontally in the front-rear direction of the vehicle body when viewed from the side, and is formed so that a part of the catalyst case 6 side is inclined obliquely upward. In addition, as shown in FIG. 7 in a plan view, a part of the suspension frame 8 side is disposed so that it faces obliquely to the left.

The above-mentioned exhaust heat recovery device 7 includes: an exhaust gas flow path 71 formed inside the outer cylinder 7a; and a heat exchange medium (coolant) passage 72 of fixed length, including The inner cylinder 7b is arranged concentrically inside the outer cylinder 7a. Between the outer cylinder 7a and the inner cylinder 7b, heat transfer fins 73 are radially provided on the peripheral surface of the inner cylinder 7b. The heat transfer fins 73 are provided between the exhaust gas passage 71 and the heat exchange medium passage 72 with a fixed length L in the axial direction.

The heat exchange medium passage 72 has an input pipe 74 for introducing the heat exchange medium and an output pipe 75 for discharging the heat exchange medium connected to the front and rear sides of the heat exchange medium passage 72 . The input pipe 74 is provided on the downstream side of the recoverer main body 70 , and the output pipe 75 is provided on the upstream side of the recoverer main body 70 .

The input pipe 74 connects the exhaust heat recovery device 7 to a heater core described later, and the output pipe 75 connects the exhaust heat recovery device 7 to a water inlet pipe or a radiator outlet pipe described later.

In addition, as shown in FIG. 7 , it is preferable that the output pipe 75 is provided on the alternator side (the right side of the vehicle) with respect to the centerline of the exhaust heat recovery device 7 in a plan view of the vehicle. As a result, the distance between the output pipe 75 and the drain water pipe 76 from the radiator 4 can be shortened, so that the cooling water path reciprocating between the engine 1 and the exhaust heat recovery device 7 can be further shortened.

Either of the input pipe 74 and the output pipe 75 may be arranged on the front side of the vehicle in the vehicle front-rear direction.

In addition, the exhaust gas flow path 71 and the heat exchange medium passage 72 may be arranged at an eccentric position of the outer cylinder 7 a of the recovery main body 70 as shown in FIG. 9( b ). . In addition, as shown in (c) of FIG. 9, heat exchange medium passages ₇₂₂ formed in a polygonal shape may be used.

As shown in FIG. 8, the above-mentioned exhaust heat recovery device 7 is configured so that the flow direction X of the exhaust gas in the exhaust gas passage 71 of the recovery device main body 70 and the flow direction Y of the heat exchange medium in the heat exchange medium passage 72 become opposite directions, so that The exhaust gas is efficiently cooled by the heat transfer fins 73 .

10 shows the flow of the heat exchange medium cooling the engine 1, the heat exchange medium heated by cooling the engine 1 is sent to the heater (heater core) 10, heats the heater 10 and is supplied to the above-mentioned Exhaust heat recovery device7. The heat exchange medium heated by the exhaust gas from the exhaust heat recovery unit 7 joins the heat exchange medium cooled by the radiator 4 and is supplied to the engine 1 through the water pump 11 . The exhaust heat recovery device 7 is connected to the water pump 11 through a discharge water pipe (radiator outlet pipe 41 or water inlet pipe 42 ) 76 connected to the outlet pipe 75 .

The heat exchange medium from the engine 1 is also sent to the temperature control valve 12 , supplied to the CVT (continuously variable transmission) cooler 13 and then supplied to the engine 1 through the water pump 11 .

According to the above-mentioned embodiment, the temperature of the exhaust gas in the exhaust pipe below the bottom of the oil pan 2 near the catalytic converter housing 6 where the catalytic converter is installed is 150° higher than the temperature of the exhaust gas in the exhaust pipe under the floor passage. ~200°C temperature. Therefore, when the exhaust heat recovery device 7 is arranged under the floor aisle, when it is arranged under the bottom of the oil pan 2, the temperature difference with the heat exchange medium is larger, and the amount of exhaust heat recovery is larger. . Furthermore, by arranging the exhaust heat recovery device 7 at a position above a plane including the lower end position of the suspension frame 8, that is, a horizontal plane extending the lower surface of the suspension frame 8, the exhaust heat recovery device can 7 is closer to the oil pan 2, which can increase the amount of heat radiation from the exhaust gas to the oil pan. Therefore, it is possible to increase the amount of recovered heat recovered to the heat exchange medium, and to shorten the time required for preheating.

In the above embodiment, since the exhaust heat recovery device 7 is placed close to the engine 1 and below the bottom of the oil pan 2, the heat exchange medium flow path 72 between the engine 1 and the exhaust heat recovery device 7 is shortened. .

Therefore, the capacity of the heat exchange medium held inside can be reduced. Therefore, since the delay in temperature rise of the heat exchange medium can be suppressed, the heat exchange medium can be easily warmed, so the time required for warming up can be shortened, and weight reduction can also be achieved.

Furthermore, since the heat dissipation area from the heat exchange medium flow path 72 can be reduced, the amount of heat dissipation can be reduced, so that the heat recovered by the heat exchange medium can be suppressed from being released into the atmosphere before being used for preheating. Therefore, the time required for warming up can be shortened, the load on the water pump 11 can be suppressed, and the reduction in the output of the engine 1 can be suppressed.

When the exhaust heat recovery device 7 is arranged under the floor tunnel, the interior space of the vehicle will be squeezed, but in the present invention, since the exhaust heat recovery device 7 is not arranged under the floor tunnel, the interior space of the vehicle will not be squeezed. Therefore, the space in the vehicle can be enlarged, and the comfort of the occupant can be improved.

In addition, the degree of freedom of design around the floor passage is increased.

Since the exhaust heat recovery device 7 is arranged above the horizontal plane H including the lower end position of the suspension frame 8, in the event of an accident, the suspension frame 8 located near the exhaust heat recovery device 7 will also contact with the suspension frame 8 first. contact with the ground, and the exhaust heat recovery device 7 can be suppressed from contacting the ground. Therefore, damage to the exhaust heat recovery device 7 can be suppressed.

The inlet pipe 74 and the outlet pipe 75 of the heat exchange medium are provided in the exhaust heat recovery unit 7, and both the inlet pipe 74 and the outlet pipe 75 are arranged above the plane including the lower end position of the suspension frame 8. , the suspension frame 8 first comes into contact with the ground, and the input pipe 74 and the output pipe 75 included in the exhaust heat recovery device 7 are prevented from coming into contact with the ground. Therefore, damage to the exhaust heat recovery device 7 can be suppressed.

The output pipe 75 is connected to the discharge water pipe 76 arranged between the radiator 4 and the water pump 11 of the engine 1 through a pipe body (not shown). Therefore, when the warm-up operation is performed, the heat exchange medium ( Cooling water) does not pass through the radiator 4, so it will not be cooled by the radiator 4. In addition, since the distance between the output pipe 75 and the water pump 11 is short, the heat exchange medium (cooling water) can reach the water pump 11 immediately while maintaining the recovered heat. Therefore, the time taken for warming up can be shortened.

The pipe body is arranged between the discharge water pipe 76 and the catalytic converter case 6 , and therefore, compared with the case where the pipe body is not arranged between the discharge water pipe 76 and the catalytic converter case 6 , the discharge water Since the piping 76 is less likely to receive radiant heat from the catalyst, the temperature of the cooling water passing through the drain water piping 76 is less likely to rise. Therefore, after the warm-up operation is completed, the exhaust water from the radiator 4 can suppress the temperature caused by the catalyst compared with the case where the pipe body is not disposed between the exhaust water pipe 76 and the catalyst case 6 . rise. Therefore, the volume of the radiator 4 can be reduced, and the engine 1 can be sufficiently protected.

The discharge water of the heater (heater core) 10 is input to the above-mentioned input pipe 74, so that the heat recovery to the cooling water can be suppressed compared to the case where the heater (heater core) 10 is not cooled.

Therefore, the heat blocking performance (the performance of not recovering heat required after the warm-up operation is completed) is improved.

The exhaust heat recovery device 7 is connected between the input pipe 74 and the output pipe 75, and includes: a first flow path 72A serving as a heat exchange medium passage 72 provided in the inner cylinder 7b through which a heat exchange medium passes; and a second flow path 72A. The flow path 71A, which is the exhaust gas flow path 71 provided between the inner cylinder 7b and the outer cylinder 7a of the exhaust heat recovery device 7, is provided close to the second flow path 71A at least on the side of the oil pan 2, so that it can Play the following effect.

The exhaust heat recovery device such as the conventional patent document 1 has a structure in which a cooling water flow path is arranged on the outer peripheral side of the heat exchange part, so the radiant heat due to the temperature of the cooling water at about 90°C is transferred to the oil pan. 2. In the case of the structure of the exhaust heat recovery device 7 of the present invention, the exhaust gas on the outer cylinder 7a side as the second flow path 71A is arranged on the outer peripheral side of the cooling water passage 72 as the heat exchange part of the first flow path 72A. Due to the structure of the gas flow path 71 , radiant heat due to the temperature of the exhaust gas having a temperature as high as about 300 to 500° C. is transferred to the oil pan 2 .

Therefore, when the exhaust heat recovery device 7 is arranged below the oil pan bottom 2a in the present invention, higher-temperature heat is recovered to the engine oil than when the exhaust heat recovery device 7 is arranged under the floor tunnel. middle.

Thus, the recovered heat recovered to the oil can be increased.

The exhaust pipe ₅₂ has a curved portion 5a that bends from below the oil pan bottom 2a toward the top of the drive shaft, and the vehicle rear end portion of the first flow path 72 is located on the vehicle front side of the curved portion. The following effects.

The inside of the exhaust pipe below the oil pan bottom 2a has a shape in which condensed water tends to accumulate. Here, if the first flow path 72A on the side of the inner cylinder 7b of the present invention is a flow path of the heat exchange medium of cooling water, and the second flow path 71A on the side of the outer cylinder 7a is the exhaust gas flow path 71, then the first flow path 72A and the The heat exchange in the second channel 71A is not affected by the condensed water or the ice formed by the condensed water. Therefore, efficient heat exchange can be maintained.

Since the vehicle rear end portion of the first flow path 72A is located closer to the vehicle front side than the vehicle front end of the engine torque rod of the engine, thermal deformation of the engine torque rod can be prevented.

Industrial availability

In the above embodiment, cooling water is used as the heat exchange medium, but the heat exchange medium may be a liquid other than water, or may be a gas. In addition, it is not limited to gasoline engines but can also be applied to diesel engines.

The inlet pipe 74 is preferably provided on the transmission side (the left side of the vehicle) with respect to the center line of the exhaust heat recovery device 7 in a plan view of the vehicle, as shown in FIG. 7 .

Since the distance between the inlet pipe 74 and the heater core 10 can be shortened, the cooling water path between the engine 1 and the exhaust heat recovery unit 7 can be further shortened.

The output pipe 75 is preferably provided on the alternator side (the right side of the vehicle) with respect to the centerline of the exhaust heat recovery device 7 in a plan view of the vehicle, as shown in FIG. 7 .

The distance between the output pipe 75 and the drain water pipe 76 from the radiator 4 can be shortened, so that the cooling water path between the engine 1 and the exhaust heat recovery device 7 can be further shortened.

Either of the input pipe 74 and the output pipe 75 may be arranged on the front side of the vehicle in the vehicle front-rear direction.

In addition, it is preferable that the output pipe 75 is disposed on the front side of the vehicle to further shorten the cooling water path between the engine 1 and the exhaust heat recovery device 7 .

Thermoelectric elements may also be provided. Exhaust heat can be used to generate electricity through thermoelectric elements.

In addition, the thermoelectric element may be any one of the exhaust heat recovery device 7 as a heat transfer part or the oil pan 2 as a heat receiving part. In addition, it is needless to say that it can be appropriately modified and implemented within a range that does not change the technical scope of the present invention.

Claims (9)

1. a kind of exhaust gas heat recovery device, has：Engine at least has oil sump；Exhaust pipe is used to that engine to be discharged The gas of discharge；Catalyst converter, part of it or all set on the vehicle front of engine purify discharge gas；And Heat exchange medium, above-mentioned exhaust gas heat recovery device have the row that heat exchange is carried out between above-mentioned heat exchange medium and discharge gas Gas heat regenerator, above-mentioned exhaust gas heat recovery device be characterized in that,

Above-mentioned exhaust gas heat recovering instrument is set to the midway of the exhaust pipe in the downstream side of catalyst converter, and one of above-mentioned exhaust gas heat recovering instrument Divide the lower section for being at least set to above-mentioned oil sump bottom.

2. exhaust gas heat recovery device according to claim 1, which is characterized in that

A part for above-mentioned exhaust gas heat recovering instrument is at least set to the lower surface of above-mentioned oil sump bottom and includes suspension frame lower end Between the plane of position.

3. exhaust gas heat recovery device according to claim 2, which is characterized in that

The input pipe and efferent duct of heat exchange medium are equipped in above-mentioned exhaust gas heat recovering instrument, above-mentioned input pipe and efferent duct are all provided with In the position more against the top than the plane comprising above-mentioned suspension frame lower end position.

4. exhaust gas heat recovery device according to claim 3, which is characterized in that

Above-mentioned efferent duct is by tube body and configures the discharge water piping connection between the radiator and water pump of above-mentioned engine.

5. exhaust gas heat recovery device according to claim 4, which is characterized in that

Above-mentioned tubular body configuration is between the piping of above-mentioned discharge water and above-mentioned catalyst converter.

6. the exhaust gas heat recovery device according to any one of claim 3 to 5, which is characterized in that

The discharge water of heater core is input to above-mentioned input pipe.

7. the exhaust gas heat recovery device according to any one of claim 3 to 6, which is characterized in that

Above-mentioned exhaust gas heat recovering instrument has：First flow path is used for heat exchange medium and passes through；And second flow path, being set to should The peripheral part of first flow path, passes through for discharge gas, and second flow path configures between first flow path and oil sump.

8. exhaust gas heat recovery device according to claim 7, which is characterized in that

Above-mentioned exhaust pipe has the bending section being bent from the top underneath towards drive shaft of oil sump bottom, the vehicle of first flow path Rear end part is located at the position that vehicle front side is leaned on than above-mentioned bending section.

9. exhaust gas heat recovery device according to claim 7 or 8, which is characterized in that

The front of the car that the rear vehicle end part of above-mentioned first flow path is located at the engine torque bar than above-mentioned engine leans on vehicle The position of front side.