DE102008009212A1 - Exhaust heat recovery device - Google Patents

Abstract

A Device for recovering the exhaust heat closes an evaporation unit (1), a condensation unit (2), a evaporator-side connecting part (61) and a condensation-side connecting part (62). The evaporation unit (1) is arranged in an exhaust gas duct, through which an exhaust gas flows and the heat exchange between the exhaust gas and an operating fluid flowing therein performs, whereby the operating fluid is evaporated. The condensation unit (2) is disposed in a coolant passage through which an engine coolant flows, and takes the heat exchange between the operating fluid and the engine coolant, whereby the operating fluid condenses. The evaporator-side connecting part (62) connects the evaporation unit (1) to the condensation unit (2) for introducing evaporated working fluid into the condensation unit (2). The condensation-side connecting part (62) connects the Condensation unit (2) with the evaporation unit (1) for insertion condensed operating fluid to the evaporation unit (1). The condensation side Connecting part (62) is connected to a throttle part (7a, 7b, 7c, 70) Mistake.

Description

The The present invention relates to an exhaust heat recovery apparatus. for a vehicle, such as an automobile, use place.

It is known to recover heat from exhaust discharged from an exhaust system of a vehicle engine using the principle of the heat pipe and to use the recovered heat for other purposes, such as warming up the engine. For example, the published unaudited Japanese Patent Application No. 62-268722 an exhaust heat recovery system for heating an engine coolant using the heat of an exhaust gas from a motor. Specifically, an evaporator unit having heat pipes is disposed in an engine exhaust passage through which the exhaust gas flows, and a condensing unit having heat pipes is disposed in an engine coolant circuit through which the coolant flows.

As another example, the published unaudited Japanese Patent Application No. 4-45393 called, which has a heat exchanger with looped heat pipe. The disclosed heat exchanger includes a looped closed circulation channel filled with an internal heat transfer fluid, an evaporator unit disposed on the circulation channel for evaporating the internal heat transfer fluid therein while receiving external heat, and a condensing unit higher on the circulation channel at one location as the evaporator unit is arranged to perform the heat exchange between the evaporated inner heat transfer fluid and an outer heat transfer fluid.

6 shows an example of a waste gas recovery device. At the in 6 shown exhaust heat recovery device, an evaporation unit J1 and a condensation unit J2 as heat exchanging Einhei th adjacent to each other in a horizontal direction. Ends of the heat pipes J3 of the evaporation and condensation units J1, J2 are coupled to collectors (connection parts) J5 so that the heat pipes J3 of the evaporation unit J1 are in communication with the heat pipes J3 of the condensing unit J2 via the collectors J5.

In such exhaust heat recovery devices the temperature of the engine coolant is increased immediately, by the heat of the exhaust gas, especially during cold start the machine as in winter, is recovered. Therefore, be Fuel efficiency and network operation improved. on the other hand it is in a full engine operation, for example, in the hot Summer, necessary, the recovery of heat restrict the exhaust gas or throttle, so as to overheat the To avoid motor.

It For example, the exhaust heat recovery apparatus has been proposed with a valve unit, for example a membrane-type valve unit, provided to stop the circulation of the operating fluid. The Membrane-type valve unit is composed of a membrane, the depending on the pressure of the operating fluid and one Valve body which is actuated by the membrane. The valve unit prevents excessive recovery of heat.

The The present invention has been made in view of the above ratios and it is an object of the present invention to provide an exhaust heat recovery apparatus to provide that is capable of excessive recovery to restrict heat in a simple construction.

According to one Aspect of the present invention includes a waste gas recovery apparatus an evaporation unit, a condensation unit and a evaporation side Connecting part, a condensation-side connecting part and a throttle part. The evaporation unit is in an exhaust passage to dispose, through which an exhaust gas discharged from an engine is, flows to the heat exchange between the Exhaust gas and a working fluid flowing therein, whereby the operating fluid evaporates. The condensation unit is to be arranged in a coolant passage through which a Motorkühlühlmit tel flows to the heat exchange between the engine coolant and the operating fluid that evaporates in the evaporation unit was, whereby the operating fluid is condensed. The evaporation side Connecting part connects the evaporation unit and the condensation unit, vaporized operating fluid from the evaporation unit to the condensation unit respectively. The condensation-side connecting part connects the condensation unit with the evaporation unit for insertion condensed operating fluid from the condensation unit in the Evaporation unit. The throttle part is in the condensation side Connecting part arranged.

Of the Throttle is configured to be excessive Restricted recovery of waste heat. Thus, an excessive recovery of heat through the choke part, which is a simple construction has limited.

For example is the throttle part of a fixed throttle and an opening built up. An upper limit of the amount of in the exhaust heat recovery device recovered heat can be determined by an opening degree of an opening of the throttle part and the amount of in the exhaust heat recovery device enclosed operating fluid is set.

When Another example is the throttle part with a variable throttle which is capable of opening an opening, through which the operating fluid passes, corresponding to a temperature of Change operating fluids or vary.

According to one second aspect of the present invention includes a Off (gas) heat recovery device, an evaporation unit, a Condensation unit, an evaporation-side connection part and a condensation-side connecting part. The evaporation unit is to be arranged in the exhaust heat channel, through which an exhaust gas flows to the heat exchange between the Exhaust gas and a working fluid flowing therein, whereby the operating fluid is evaporated. The condensation unit is to be arranged in a cooling channel, through which an engine coolant flows to the heat exchange between the engine coolant and the operating fluid contained in the evaporation unit was evaporated, whereby the operating fluid condenses. The evaporation side Connecting part connects the evaporation unit and the condensation unit and defines a channel for introducing the operating fluid from the evaporation unit to the condensation unit. The condensation side Connecting part connects the condensation unit and the evaporation unit and defines a channel for introducing the operating fluid from the condensation unit into the evaporation unit. The condensation side Connecting part comprises a throttle part, which has a reduced passage area or a reduced channel area features.

Consequently will excess recovery of Heat thereby limited by partially the passage area the condensation-side connecting part is limited.

Other Objects, features and advantages of the present invention will become more apparent from the following detailed description, with reference to the appended Drawings reference is made in which like parts with like Reference numerals are designated, and in which:

1 Fig. 3 is a schematic cross section through an exhaust heat recovery apparatus according to a first embodiment of the invention;

the 2A and 2 B Fig. 3 are conceptual diagrams to show the operation of an exhaust heat recovery apparatus as a comparative example;

the 2C and 2D FIG. 15 is conceptual diagrams to show the operation of the exhaust heat recovery apparatus according to the first embodiment; FIG.

3A FIG. 15 is an enlarged schematic cross-sectional view of an evaporation side connecting part of an exhaust heat recovery apparatus when the temperature of the operating fluid is low, according to a second embodiment of the present invention; FIG.

3B Fig. 10 is an enlarged schematic sectional view of the evaporation side connection part of the exhaust heat recovery apparatus in a state when the temperature of the operation fluid is high, according to a second embodiment of the present invention;

4 Fig. 10 is a schematic section through a condensation-side connecting part of an exhaust heat recovery apparatus according to a third embodiment of the present invention;

5 Fig. 10 is an enlarged sectional view of a schematic sectional view of a condensation-side connecting part of an exhaust heat recovery apparatus according to another embodiment of the present invention; and

6 is a schematic section through a device for recovering the exhaust heat of another type.

First Embodiment

According to one first embodiment of the present invention in a vehicle driven by an engine (for example, an internal combustion engine) is driven to remove waste heat from an exhaust gas from a To recover exhaust system of an internal combustion engine and the heat to facilitate a warm up of the Motors or the like to use.

The exhaust heat recovery apparatus generally includes an evaporation unit 1 and a condensation unit 2 , The evaporation unit 1 is in a first case 100 disposed in communication with an exhaust passage (not shown) through which the exhaust gas discharged from the engine flows. In the present lowing embodiment, for example, the first housing 100 in an exhaust pipe through which exhaust gas flows. The evaporation unit 1 takes heat exchange between the exhaust gas and an operating fluid flowing therein, thereby vaporizing the operating fluid.

The condensation unit 2 is located outside the exhaust pipe. The condensation unit 2 is in a second housing 200 disposed in communication with a coolant channel (not shown) of the machine, through which coolant flows. The condensation unit 2 takes the heat exchange between the working fluid that is in the evaporation unit 1 and the engine coolant, thereby condensing the operating fluid. The second housing 200 has a coolant inlet opening 201 and a coolant outlet port 202 , The coolant inlet opening 201 is coupled to the coolant channel at a location downstream of the engine to direct the coolant into the second housing 201 to lead. The coolant outlet 202 is coupled to the coolant passage at a location upstream of the engine to remove the coolant from the second housing 200 to introduce into the coolant channel.

For example, in the present embodiment, the first housing 100 and the second housing 200 arranged adjacent to each other. There is also a gap between the first housing 100 and the second housing 200 intended.

The evaporation unit 1 has a large number of evaporation-side heat pipes 3a and evaporation side ribs 4a connected to the outer surfaces of the heat pipes 3a are connected. At the ribs 4a These are, for example, corrugated ribs. Each of the heat pipes 3a has a substantially flat tubular shape. The heat pipe 3a is oriented so that its longitudinal axis is in a vertical direction V, for example, an upward / downward direction in 1 extends. Also, the heat pipe 3a oriented such that a major axis of a in a direction perpendicular to the longitudinal axis of the tube 3a oriented main axis is substantially parallel to a flow direction of the exhaust gas, for example in a direction perpendicular to the plane of the drawing 1 , The heat pipes 3a are stacked parallel to each other in a tube stacking direction H, for example, in a horizontal direction.

The evaporation unit 1 has evaporation-side collectors 5a at both ends of the heat pipes 3a , The collectors 5a extend in the tube stacking direction H to communicate with all the heat pipes 3a get. One of the collectors 5a , which connects to the upper ends of the heat pipes 3a stands, becomes the first evaporation-side collector 51a , and the other collector 5a , which connects to the lower ends of the heat pipes 3a stands, as the second evaporation-side collector 52a designated.

The condensation unit 2 includes condensation-side heat pipes 3b and condensation-side ribs 4b attached to the outer surfaces of the heat pipes 3b are connected. At the ribs or fins 4b These are, for example, corrugated ribs. The heat pipes 3b are essentially flat tubes. Each of the heat pipes 3b is oriented so that its longitudinal axis in the vertical direction V Rich, for example, in the upward / downward direction in 1 , extends. Also, the heat pipe 3b oriented such that a major axis of a in a direction perpendicular to the longitudinal axis of the tube 3b defined cross-section substantially parallel to the flow direction of the exhaust gas of the evaporation unit 1 is, for example, in the direction perpendicular to the plane of the 1 , The heat pipes 3b are stacked parallel to each other in the tube stacking direction H, for example, in the horizontal direction.

The condensation unit 2 includes condensation-side collectors 5b at the two ends of the heat pipes 3b , The collectors 5b extend in the tube stacking direction H, in conjunction with all heat pipes 3b to step. One of the collectors 5b , which connects to the upper ends of the heat pipes 3b stands, becomes the first condensation-side collector 51b and the other collector 5b , which connects to the lower ends of the heat pipes 3b stands, becomes the second condensation-side collector 52b designated.

The evaporation side collectors 5a stand in connection with the condensation-side collectors 5b over the connecting parts 6 which are substantially tubular in shape. This will be a closed looped path through the heat pipes 3a . 3b , the collector 5a . 5b and the connecting parts 6 shaped. The path is filled with operating fluid which is vaporizable and condensable, for example water, alcohol or the like. The operating fluid circulates through the evaporation unit 1 and the condensation unit 2 ,

One of the connecting parts 6 , which is arranged on an upper side and the first evaporation side collector 51a and the first condensation-side collector 51b connects, is used as the evaporation side connection part 61 designated. The operating fluid contained in the evaporation unit 1 is evaporated, is in the condensation unit 2 through the evaporation side connection part 61 introduced.

The other connection part 6 which is located on a lower side and the second evaporation side collector 52a and the second condensation-side collector 52b connects, as a condensation-side connection part 62 designated. The operating fluid contained in the condensation unit 2 is condensed, is in the evaporation unit 1 through the condensation-side connecting part 62 introduced.

The condensation-side connecting part 62 has a fixed throttle 7a as a throttle part. In the present embodiment, a throttle element 70 in the condensation-side connection part 62 arranged, and the fixed throttle 7a is through the throttle element 70 given. That is, the throttle element 70 is disposed such that a passage area (for example, a cross-sectional area) of a passage through which condensed operation fluid flows partially in the condensation-side communication part 62 is reduced.

The throttle element 70 forms an opening with a reduced cross section. For example, the throttle element 70 a shape such that a cross-sectional area of the opening gradually decreases from an upstream end to a central portion and gradually increases from the central portion to a downstream end relative to the flow of the condensed operating fluid. The throttle element 70 has a first tapered wall 701 whose inside diameter decreases from an inflow location to an outflow location with respect to the flow of the operation fluid, and a second tapered tubular wall 702 which flows continuously from an outflow end of the first tapered tubular wall 702 going on. An inner diameter of the second tapered tubular wall 702 increases from a Anströmort to a Abströmort based on the flow of the operating fluid.

Next, an operation of the exhaust heat recovery apparatus will be described. The 2A and 2 B FIG. 11 are conceptual diagrams to show the operation of an exhaust heat recovery device without a throttle part as a comparative example. FIG. The 2C and 2D FIG. 13 are conceptual diagrams to show the operation of the exhaust heat recovery apparatus of the present invention. FIG.

The 2A and 2C show conditions in which the amount Q _{ON of} the heat of the exhaust gas introduced into the exhaust heat recovery device is equal to a first value Q1. The 2 B and 2C show conditions in which the amount Q _{ON of} the heat of the exhaust gas is equal to a second value Q2 greater than the first value Q1. In the 2A to 2D is the large number of evaporator-side heat pipes 3a just by a single heat pipe 3a presented for the sake of simplicity. Similarly, the plurality of condensation-side heat pipes 3b simply through a single heat pipe 3b symbolizes. Furthermore, the representation of the ribs or fins 4a and 4b and the first and second housings 100 . 200 in the 2A to 2D omitted.

That in the evaporation unit 1 evaporated working fluid flows into the condensation unit 2 through the evaporator-side connecting part 61 , In the condensation unit 2 the operating fluid is condensed and liquefied. The liquefied operating fluid flows into the evaporation unit 1 via the condensation-side connecting part 62 ,

Due to the compensation of the evaporation of the operating fluid in the evaporation unit 1 and the condensation of the operating fluid in the condensation unit 2 is a difference h in the level of the water of the operating fluid between the evaporation unit 1 and the condensation unit 2 generated. The operating fluid becomes the evaporation unit 1 from the condensation unit 2 due to the difference in water level h returned. In this way, the operating fluid in the exhaust heat recovery apparatus is circulated.

In the exhaust heat recovery apparatus shown in FIG 2A , the pressure loss ΔP1 of a backflow of the operating fluid and the difference in the water level h satisfy the following relationship: ΔP1 = ρgh

In the above equation, ρ denotes the density of the operating fluid in a liquid phase, and g denotes the gravitational acceleration. Here, the density ρ of the operating fluid and the gravitational acceleration g are constant. Thus, when the amount Q _{ON of} the heat of the exhaust gas is constant, the difference h of the water level is determined by the pressure loss ΔP1. Q _OFF denotes the amount of heat applied to the refrigerant in the condensation unit 2 was transferred.

As in 2 B As shown, as the amount Q _{ON of} the heat of the exhaust gas increases, the amount of recirculated flow of the operating fluid increases. This increases the flow rate of the operating fluid. Thus, the pressure loss ΔP1 increases the backflow of the operating fluid, and thus the difference h in the water level increases.

At the present in 2C shown embodiment, since the condensation side connecting part 62 with the fixed throttle 7a is provided, the pressure loss ΔP 'of the return flow of the operating fluid by the sum of the pressure loss .DELTA.P1 and the pressure loss .DELTA.P2 due to the fixed throttle 7a determined (that is, ΔP '= ΔP1 + ΔP2). In this case, the water level difference h2 is between the evaporation unit 1 and the condensation unit 2 greater than the water level difference h (the difference in water levels) in 2A shown apparatus for recovering the exhaust heat, by the amount of pressure drop ΔP2 the fixed throttle 7a ,

Then, when the amount Q _{ON of} the heat of the exhaust gas increases, shown in FIG 2D , then the pressure loss ΔP 'of the return flow of the operating fluid increases. As a result, the water level difference h2, which is necessary for the return of the operating fluid, is increased. When it becomes difficult to maintain the water level difference h2 necessary for returning the operation fluid, the amount to the evaporation unit becomes 1 limited recirculated operating fluid. Thus, the amount of heat in the plateaus of the exhaust heat recovery apparatus increases.

In the present embodiment, a fixed throttle 7a in the condensation-side connecting part 62 intended. The upper limit of the heat recovered in the heat recovery apparatus is determined by presetting the opening degree of the fixed throttle 7a , For example, the passage area of the opening of the fixed throttle 7a and the amount of the operation fluid filled in the exhaust heat recovery apparatus. Thus, the structure for restricting excessive heat recovery is simplified as compared with a device for recovering the exhaust heat with a diaphragm valve type unit constructed of a diaphragm, a valve body, and the like.

Second Embodiment

A second embodiment of the invention will now be described with reference to FIGS 3A and 3B to be discribed. Components similar to those of the first embodiment are denoted by the same reference numerals, the description of which is not repeated.

In the second embodiment, the condensation-side connecting part 62 with a variable throttle 7b as a throttle part instead of the fixed throttle 7a provided the first embodiment. The variable throttle 7b is configured to change the opening degree of an opening defined therein, that is, the cross-sectional area of the operating fluid passage corresponding to the temperature of the operation fluid.

3A shows a state of the variable throttle 7b when the temperature of the operating fluid is low, and 3B shows a state of the variable throttle 7b when the temperature of the operating fluid is high. The variable throttle 7b is configured so that the opening degree is reduced according to an increase in the temperature of the operating fluid.

In the present embodiment, the variable throttle 7b made of a material that is deformable according to the ambient temperature. For example, the material of the variable throttle 7b a bi-metal, a shape memory alloy, or the like. Furthermore, in the present embodiment, the variable throttle 7b configured so that the passage of the operating fluid is not fully closed, even if the temperature of the condensing-side connecting part 62 flowing operating fluid is increased.

Next, an operation of the exhaust heat recovery apparatus of the second embodiment will be described. As the amount Q _{ON of} the heat of the exhaust gas increases, the amount of heat recovered in the exhaust heat recovery apparatus also increases. In the present embodiment, the variable throttle 7b in the condensation-side connecting part 62 intended. As the amount Q _{ON of} the heat of the exhaust gas increases, the temperature of the operating fluid also increases. Thus, the opening degree of the variable throttle reduces 7b with an increase in the temperature of the operating fluid and thus the pressure loss ΔP2 increases. Thus, an increase in the amount of recovered heat in the exhaust heat recovery apparatus is limited to a certain point. As the amount Q _{ON of} the heat of the exhaust gas further increases, the opening degree of the variable throttle decreases 7b continue, and thus the pressure loss ΔP2 continues to increase. As a result, the amount of back-flowing operating fluid is reduced and thus the amount of the exhaust heat recovery device.

In the present embodiment, the condensation-side connection part is 62 with the variable throttle 7b provided that varies the opening degree in accordance with the increase in the temperature of the operating fluid. Therefore, the amount of heat recovered in the exhaust heat recovery apparatus is reduced in accordance with the increase in the temperature of the operation fluid. Since the amount of heat recovered in the exhaust heat recovery apparatus is limited when the engine load is large, for example, in the summer when the temperature of the operation fluid is high, the heat is less likely to be generated Engine is overheating.

Third Embodiment

A third embodiment of the present invention will now be described with reference to FIG 4 to be discribed. The components similar to those of the first embodiment are denoted by the same reference numerals, and description thereof will therefore not be repeated.

As in 4 As shown, the exhaust heat recovery apparatus of the present embodiment has a variable throttle 7c in the condensation-side connection part 62 as a throttle part. The variable throttle 7c includes an opening 71 , a valve body 72 for opening and closing the opening 71 and a temperature-sensitive deformable element 73 , One end of the deformable element 73 is with an end wall of the valve body 72 on one side of the opening 71 connected to. An opposite end of the deformable element 73 is with a carrier element 74 connected in the condensation-side connecting part 62 is arranged.

The deformable element 73 is deformable depending on the temperature. For example, the deformable element 73 is configured to thermally expand when the temperature of the condensing-side connection part 62 going operating fluid exceeds a predetermined temperature. The deformable element 73 is made of, for example, thermal wax, thermo-metal or the like, and has a coefficient of thermal expansion larger than that of the metal of the condensation-side connecting part 62 is.

When the temperature of the condensation-side connecting part 62 going operating fluid increases, the valve body 70 moved in one direction, in which the opening degree of the opening 71 reduced. On the other hand, when the temperature of the condensing-side connecting part 62 going operating fluid is reduced, the valve body 72 moved in one direction in which the opening degree of the opening 71 is enlarged. In the present embodiment, the valve body closes 72 not the opening 71 completely, even if the temperature of the condensing-side connecting part 62 going operating fluid is increased.

Since the condensation-side connecting part 62 with the variable throttle 7c is equipped, which the opening degree of the opening 71 varies according to an increase in the temperature of the operating fluid, the amount of heat recovered in the exhaust heat recovery apparatus is reduced in accordance with an increase in the temperature of the operating fluid. Thus, effects similar to those of the second embodiment are achieved.

Other Embodiments

In the first embodiment, the throttle element forms 70 the opening whose inside diameter gradually reduces from the upstream side to the middle location and gradually increases from the middle location to the downstream side with respect to the flow of the operating fluid. However, the shape of the opening of the throttle element 70 not limited to the above. For example, the throttle element 70 have a cylindrical shape and have a substantially constant passage area.

In the first embodiment, the fixed throttle 7a through a throttle element 70 educated. However, the fixed throttle 7a partially formed by the passage area (that is, the inner diameter) of the condensation-side connecting portion 62 , as in 5 shown is reduced. In this case, the number of components is reduced. Furthermore, the pressure loss ΔP2 of the fixed throttle 7a determined by an inner diameter d and a length L of the fixed throttle 7a be set.

In the second and third embodiments, the variable throttles 7b . 7c arranged to directly contact the operating fluid, and the opening degrees of the variable throttles 7b . 7c are mechanically controlled according to the temperature of the operating fluid. Alternatively, a temperature sensor may be used separately to detect the temperature of the operating fluid flowing through the condensation-side connector 62 goes; and the variable throttle 7b . 7c can be configured so that its opening degrees are electrically controlled based on the temperature detected by the temperature sensor.

In the above embodiments, the condensation-side connecting part is 62 for example horizontally oriented. The orientation of the condensation-side connecting part 62 but is not limited to the above. The condensation-side connecting part 62 may be inclined relative to the horizontal direction.

additional Advantages and configurations are obvious the expert. The invention is therefore in its broader entirety not to specific details, illustrated devices and illustrative Examples as shown and described are limited.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - JP 62-268722 [0002]
• - JP 4-45393 [0003]

Claims (6)

A device for recovering the exhaust gas heat, comprising: an evaporation unit ( 1 ) to be disposed in an exhaust passage through which exhaust gas exhausted from an engine flows, for effecting heat exchange between the exhaust gas and an operating fluid flowing therein, thereby vaporizing the operation fluid; a condensation unit ( 2 ) to be disposed in a coolant passage through which a coolant flows, for effecting the heat exchange between the engine coolant and the operation fluid vaporized in the vaporization unit, thereby condensing the operation fluid; an evaporator-side connecting part ( 61 ) containing the evaporation unit ( 1 ) and the condensation unit ( 2 ) connects the operating fluid from the evaporation unit to the condensation unit ( 2 ) respectively; a condensation-side connecting part ( 62 ), the condensation unit ( 2 ) with the evaporation unit ( 1 ) to the operating fluid from the condensation unit ( 2 ) to the evaporation unit ( 1 ) respectively; and a throttle part ( 7a . 7b . 7c . 70 ), which in the condensation-side connection part ( 62 ) is arranged. Exhaust heat recovery apparatus according to claim 1, wherein said throttle member is a fixed throttle ( 7a . 70 ). Exhaust gas heat recovery apparatus according to claim 2, wherein said fixed throttle ( 7a ) is provided by partially a passage area of the condensation-side connecting part ( 62 ) is reduced. Exhaust gas heat recovery device according to claim 1, wherein the throttle part is a variable throttle ( 7b . 7c ) configured to vary an opening degree of an opening through which the operation fluid flows according to a temperature of the operation fluid. Exhaust gas heat recovery device according to claim 4, wherein the variable throttle ( 7b . 7c ) is configured such that the opening degree is reduced in accordance with an increase in the temperature of the operating fluid. A device for recovering the exhaust gas heat, comprising: an evaporation unit ( 1 ) to be disposed in an exhaust passage through which exhaust gas exhausted from an engine flows, for performing the heat exchange between the exhaust gas and an operating fluid flowing therein, thereby vaporizing the operation fluid; a condensation unit ( 2 ) to be disposed in a coolant passage through which an engine coolant flows, for effecting heat exchange between the engine coolant and the operation fluid contained in the vaporization unit (10). 1 ) was evaporated, whereby the operating fluid is condensed; an evaporator-side connecting part ( 61 ) containing the evaporation unit ( 1 ) and the condensation unit ( 2 ) and defines a passage or channel to remove the operating fluid from the vaporization unit (FIG. 1 ) to the condensation unit ( 2 ) respectively; and a condensation-side connecting part ( 62 ), the condensation unit ( 2 ) with the evaporation unit ( 1 ) and defines a passage or channel to remove the operating fluid from the condensing unit ( 2 ) to the evaporation unit ( 1 ), wherein the condensation-side connecting part ( 62 ) a throttle part ( 7a ) having a reduced passage area.