JP2006317013A - Heat pipe and waste heat recovering device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a waste heat recovering device capable of switching between operation and suspension of heat transport at low cost when used for a bottom heat type, and preventing dropping of condensed working medium to an evaporator side. <P>SOLUTION: In this heat pipe having an evaporating portion 110A set at one end of a tubular closed container 111 and using heat of an outside high temperature part to cause the inside working medium to evaporate, and a condensing portion 110B set at the other end side of the closed container 111 and radiating heat to an outside low temperature part 30 to cause the evaporated working medium to condense, the evaporating portion 110A is arranged below the condensing portion 110B, and a holding means 112 for holding the liquefied working medium condensed by the condensing portion 110B along with an increase in the amount of heat received by the evaporating portion 110A to prevent return to the evaporating portion 110A. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a heat pipe suitable for recovering exhaust heat of an exhaust gas of an internal combustion engine for a vehicle and applying it to cooling water heating of the internal combustion engine, and an exhaust heat recovery apparatus using the heat pipe.

  Conventionally, as a vehicle heating device using a heat pipe, for example, one disclosed in Patent Document 1 is known. This is because the evaporation part of the heat pipe (loop type) is arranged in the exhaust passage of the engine, the condensing part of the heat pipe is arranged on the air outlet side of the heater core for heating, and the exhaust pipe heat is heated by the heat pipe. It is transported directly to the vehicle, and heating performance is ensured in a short time after the engine is started.

In the above vehicle heating device, the valve means is provided in the middle of the heat pipe. When the heating air temperature obtained by the temperature sensor reaches a predetermined value, the valve means is closed and the heat transport by the heat pipe is stopped. To be.
Japanese Utility Model Publication No.59-16211

  However, when using the so-called bottom heat type in which the evaporation part of the heat pipe is arranged on the lower side and the condensation part is arranged on the upper side with respect to the technique described in Patent Document 1, the condensation is performed in the condensation part when the operation of heat transport is stopped. If the water droplets drop on the evaporation section due to vibrations during vehicle running, etc., rapid evaporation occurs, so the internal pressure of the heat pipe suddenly rises and the heat pipe bursts or the heat pipe breaks due to repeated pressure fluctuations There is a risk of doing. Such a phenomenon is particularly remarkable in a wickless bottom heat type heat pipe.

  In view of the above problems, an object of the present invention is to enable switching between heat transport operation and stop when used as a bottom heat type, and to prevent dripping of condensed working medium on the evaporation portion side. An object of the present invention is to provide a heat pipe and an exhaust heat recovery apparatus using the heat pipe.

  In order to achieve the above object, the present invention employs the following technical means.

  In the first aspect of the present invention, an evaporating section (110A) that is set on one end side of the tubular sealed container (111) and evaporates the internal working medium by the heat of the external high temperature section (11), and a sealed container ( 111), the heat pipe having a condensing part (110B) for condensing the evaporated working medium by radiating heat to the external low temperature part (30), the evaporating part (110A) is a condensing part (110B) is disposed below and holds the liquefied working medium condensed in the condensing unit (110B) as the amount of heat received in the evaporating unit (110A) increases, to the evaporating unit (110A). It is characterized by having holding means (112) for preventing reflux.

  As a result, the holding means (112) prevents the liquefied working medium from recirculating as the amount of heat received in the evaporation section (110A) increases, so that the heat pipe (110) when used as a bottom heat type holds it. With a simple configuration of means (112), the heat transport can be switched between operation and stop.

  Here, since the liquefied working medium at the time of stopping the heat transport is held by the holding means (112), it is possible to prevent the liquefied working medium from dropping on the evaporation section (110A) due to external vibration or the like. That is, since rapid evaporation on the evaporation section (110A) side can be prevented, the internal pressure of the heat pipe (110) suddenly rises and the heat pipe (110) bursts, or the heat pipe (110) due to repeated pressure fluctuations. There is no risk of damage.

  In the invention according to claim 2, in the heat pipe, when the evaporation section (110A) is arranged below the condensation section (110B) and the temperature of the external low temperature section (30) becomes a predetermined value or more, the condensation section ( 110B), and holding means (112) for holding the liquefied working medium condensed in 110B) and preventing reflux to the evaporation section (110A), and having the same effect as the invention of claim 1 Can be obtained.

  The holding means (112) is provided between the evaporation section (110A) and the condensation section (110B) and opens and closes the return flow path (111a) of the liquefied working medium, as in the third aspect of the invention. It can be a body (112).

  In the invention according to claim 4, the valve body (112) includes the flow passage (112b) through which the vapor working medium evaporated in the evaporation section (110A) flows, and the liquefied working medium flowing out to the flow passage (112b) side. And a weir portion (112a) for preventing the above.

  Thereby, even after the valve body (112) is closed, the vapor working medium from the evaporation section (110A) reaches the condensation section (110B) through the flow path (112b) and is condensed, so that the evaporation section (110A) ) Can be prevented from increasing. Then, the liquefied working medium can be securely held by the weir portion (112a) of the valve body (112), and the inflow from the flow passage (112b) to the evaporation portion (110A) can be prevented.

  In the invention described in claim 5, the height of the weir portion (112a) is set higher by a predetermined amount than the liquid surface of the liquefied working medium that is prevented from flowing out toward the flow passage (112b). Yes.

  Thereby, in the valve body (112) according to claim 4, it is possible to provide a specific form that can surely prevent the liquefied working medium from being dropped onto the evaporation section (110A) due to external vibration or the like.

  The invention according to claim 6 is characterized in that the valve body (112) is driven by thermal expansion and thermal contraction of the thermo wax (113) provided in the condensing part (110B).

  Thereby, opening and closing of a valve body (112) is attained according to the temperature of the low temperature part (30) corresponding to a condensation part (110B). That is, when it is desired to keep the temperature of the low temperature part (30) at a predetermined temperature, the valve body (112) is closed at the predetermined temperature, and the heat transport of the heat pipe (110) can be stopped.

  Further, as in the invention described in claim 7, the holding means may be an area expanding portion that expands the inner wall surface area of the condensing portion (110B).

  Specifically, as in the invention described in claim 8, the area enlargement portion is preferably formed using a wick.

  A ninth aspect of the present invention relates to an exhaust heat recovery apparatus using the heat pipe (110) according to the first to eighth aspects, wherein the evaporation portion (110A) of the heat pipe (110) is an internal combustion engine. (10) The exhaust pipe (11) for circulating the exhaust gas is disposed, and the condensing part (110B) is disposed in the cooling water flow path (30) for circulating the cooling water of the internal combustion engine (10). The heat pipe (110) is suitable for application to the exhaust gas exhaust heat transported to the cooling water.

  In addition, the code | symbol in the bracket | parenthesis of each said means shows a corresponding relationship with the specific means of embodiment description mentioned later.

(First embodiment)
The exhaust heat recovery apparatus 100 according to the first embodiment of the present invention is applied to a vehicle (automobile) using the engine 10 as a driving source for traveling. First, a specific configuration will be described with reference to FIGS. Will be described below. 1 is a schematic view showing a state in which the exhaust heat recovery apparatus 100 is mounted on a vehicle, FIG. 2 is a side view showing the exhaust heat recovery apparatus 100, and FIG. 3 is a cross-sectional view taken along a line AA in FIG. 5 is a cross-sectional view showing the valve body 112 in the heat pipe 110, and FIG. 6 is an arrow view showing the valve body 112 seen from the direction B in FIG.

  As shown in FIG. 1, an engine 10 is a water-cooled internal combustion engine, and has an exhaust pipe (corresponding to a high temperature portion in the present invention) 11 through which exhaust gas after combustion of fuel is discharged. The exhaust pipe 11 is provided with a catalytic converter 12 for purifying exhaust gas.

  The engine 10 also includes a radiator circuit 20 that cools the engine 10 by circulation of engine cooling water (hereinafter referred to as cooling water), and a heater circuit 30 that heats conditioned air using the cooling water (hot water) as a heating source. ing.

  The radiator circuit 20 is provided with a radiator 21, and the radiator 21 cools the cooling water circulated by the water pump 22 by heat exchange with the outside air. The radiator circuit 20 is provided with a bypass passage (not shown) through which the cooling water flows around the radiator 21, and the amount of cooling water flowing through the radiator 21 and the bypass passage are bypassed by a thermostat (not shown). The amount of circulating cooling water is adjusted. In particular, during warm-up, the amount of cooling water on the bypass passage side is increased, and warm-up is promoted. That is, overcooling of the cooling water by the radiator 21 is prevented.

  The heater circuit (corresponding to the low temperature part and the cooling water flow path in the present invention) 30 is provided with a heater core 31 as a heat exchanger for heating, so that the cooling water (hot water) is circulated by the water pump 22. I have to. The heater core 31 is disposed in an air conditioning case of an air conditioning unit (not shown), and heats the conditioned air blown by the blower by heat exchange with hot water.

  As shown in FIGS. 2 and 3, the exhaust heat recovery apparatus 100 includes fins 120 provided outside a plurality (here, three) of heat pipes 110, and one end side (evaporating unit 110 </ b> A) of the heat pipe 110 is provided. The other end side (condensing part 110 </ b> B) is disposed in the water tank 140 and is formed in the exhaust pipe part 130. Each member (hereinafter described) constituting the exhaust heat recovery apparatus 100 is made of a stainless steel material having high corrosion resistance, and after each member is assembled, it is integrally formed by a brazing material provided at a contact portion or a fitting portion. It is brazed.

  The heat pipe 110 includes a container 111, a valve body 112, and a thermostat 113, and is formed by enclosing a working medium inside the container 111. The container (corresponding to the sealed container in the present invention) 111 is formed of a straight circular tube, and is used in a posture in which the longitudinal direction thereof is directed in the vertical direction. An upper end side of the container 111 is opened, and a thermostat 113 is fixed so as to close the opening. The thermostat 113 is a temperature sensitive part in which a thermo wax that expands and contracts according to temperature is enclosed. The valve body 112 is a characteristic part in this embodiment, and details thereof will be described later.

  The heat pipe 110 is provided with a sealing portion (not shown), and the heat pipe 110 is evacuated (depressurized) from the sealing portion, and after the working medium is sealed, the sealing portion is sealed. Here, water is used as the working medium. The boiling point of water is usually 100 ° C. (at 1 atm), but since the inside of the tube 110 is depressurized (for example, 0.04 atm), the boiling point is 30 to 40 ° C. As the working medium, alcohol, fluorocarbon, chlorofluorocarbon or the like may be used in addition to water.

  The heat pipe 110 having the above configuration functions as a bottom heat type by forming an evaporation unit 110A on the lower side, a condensation unit 110B on the upper side, and a heat insulating unit 110C between the two 110A and 110B.

  A plurality of heat pipes 110 are arranged, and plate-type fins 120 formed of a thin plate material are joined to the outer wall surfaces of the portions corresponding to the evaporation section 110A and the condensation section 110B of each heat pipe 110. Further, the evaporation section 110A of each heat pipe 110 is disposed in an exhaust pipe section 130 that forms a duct having a rectangular cross section, and the condensing section 110B is disposed in a water tank 140 that forms a rectangular parallelepiped container. An inlet pipe 141 and an outlet pipe 142 communicating with the water tank 140 are joined to the water tank 140 so as to face each other.

  And as a characteristic part in this embodiment, the valve seat 111b and the valve body 112 connected to the thermostat 113 and seated on the valve seat 111b are provided inside the heat pipe 110.

  4-6, the valve seat 111b is located between the evaporation part 110A and the condensation part 110B (heat insulation part 110C) of the heat pipe 110 (container 111), and from the inner wall surface 111a of the container 111. It protrudes to the axial center side and is formed in an annular shape in the circumferential direction of the inner wall surface 111a.

  The valve body 112 (corresponding to the holding portion in the present invention) is based on a disk-shaped member, and a vertical wall portion (weir in the present invention) whose cross-sectional shape extends in the vertical direction and forms a ring shape in the circumferential direction on the outer peripheral portion. 112a). Further, a plurality of hole portions (corresponding to the flow passages in the present invention) 112b having a fan shape are formed through the disk-shaped portion closer to the axial center side than the vertical wall portion 112a. Further, a shaft 112c is integrally provided at the central portion of the disk-shaped portion and is connected to the upper thermostat 113. The shaft 112c abuts on the thermo wax in the thermostat 113 and is biased toward the thermo wax by a spring member (not shown). Therefore, the temperature outside the thermostat 113 (corresponding to the temperature of the low temperature part in the present invention, specifically, the temperature of the cooling water flowing through the water tank 140) corresponds to the predetermined temperature (corresponding to the predetermined value in the present invention). Under the condition of less than 90 ° C., for example, the shaft 112c is urged toward the thermostat 113 by the spring member due to the contraction of the thermowax, and the lower end portion of the vertical wall portion 112a of the valve body 112 and the valve seat 111b are A separated state (valve open state) is set (FIG. 4).

  Further, under the condition that the temperature outside the thermostat 113 is equal to or higher than a predetermined temperature, the shaft 112c is pushed to the anti-thermostat side by the expansion of the thermowax (the expansion force of the thermowax overcomes the biasing force of the spring member), and the valve body The lower end portion of the vertical wall portion 112a of 112 is seated on the valve seat 111b (valve closed state) (FIG. 5).

  When the valve body 112 is seated on the valve seat 111b, a space M that opens upward is formed by the inner wall surface 111a, the valve seat 111b, and the vertical wall portion 112a. As will be described later, the space M is a space in which condensed water condensed in the condensing unit 110B is retained, and the volume of the space M is set to be equal to or greater than the maximum condensed water amount. In other words, the position of the upper end portion of the vertical wall portion 112a is set to be higher by a predetermined amount than the water surface at the time of the maximum amount of condensed water.

  As described above, the exhaust heat recovery apparatus 100 is formed, the exhaust pipe portion 130 is interposed in the exhaust pipe 11 on the downstream side of the catalytic converter 12, and both the pipes 141 and 142 of the water tank 140 are heater circuits. 30 (FIG. 1).

  Next, the operation based on the above configuration and the operation and effect thereof will be described with reference to FIG. FIG. 7 is a graph showing an operating state and a stopped state of the heat transport function of the heat pipe 110 with respect to the cooling water temperature.

  When the engine 10 is operated, the water pump 22 is operated, and the coolant circulates through the radiator circuit 20 and the heater circuit 30. The exhaust gas of the fuel combusted by the engine 10 flows through the exhaust pipe 11 and the exhaust pipe portion 130 through the catalytic converter 12, passes through the outside of the evaporation portion 110A of the heat pipe 110 in the exhaust heat recovery apparatus 100, and enters the atmosphere. Discharged. Further, the cooling water circulating in the heater circuit 30 circulates in the water tank 140 and passes outside the condensing unit 110B of the heat pipe 110.

  In the exhaust heat recovery apparatus 100, after the engine 10 is started, until the cooling water temperature reaches a predetermined temperature, the water (working medium) in the heat pipe 110 is evaporated by the evaporation section 110A and the exhaust pipe section as shown in FIG. It receives heat from the exhaust gas flowing through 130, evaporates into a vapor, rises in the heat pipe 110 as steam, passes through the hole 112 b of the valve body 112, and between the vertical wall portion 112 a and the inner wall surface 111 a, and the condensing portion 110 </ b> B. Flows in. The steam that has flowed into the condensing unit 110B is cooled by the cooling water flowing through the water tank 140, becomes condensed water at the inner wall surface 111a, descends due to gravity, and returns to the evaporation unit 110A along the inner wall surface 111a. The inner wall surface 111a serves as a reflux channel through which condensed water flows down and returns.

  In this way, the heat of the exhaust gas is transferred to water and transported from the evaporation unit 110A to the condensing unit 110B. When the vapor condenses in the condensing unit 110B, it is released as condensation latent heat, and the cooling water flowing through the heater circuit 30 is Heated (exhaust heat recovery operation). The heat of the exhaust gas is also transferred to the condensing unit 110B from the evaporation unit 110A by heat conduction through the outer wall surface of the heat pipe 110.

  Therefore, exhaust heat recovery by the heat pipe 110 is performed until the cooling water temperature reaches a predetermined temperature such as when the outside air temperature is relatively low or after the engine 10 is started (left side of the time axis in FIG. 7). Since the cooling water is positively heated and the warm-up of the engine 10 is promoted, the reduction of the friction loss of the engine 10 and the suppression of the fuel increase for improving the low-temperature startability are achieved and the fuel efficiency performance is improved. Be improved. Moreover, the heating performance of the heater core 31 using cooling water as a heat source is improved.

  On the other hand, when the cooling water temperature becomes equal to or higher than a predetermined temperature due to heat transport of the heat pipe 110 (or depending on the operating condition of the engine 10), the shaft 112c is pushed out to the anti-thermostat side by the thermostat 113 as shown in FIG. (The white arrow in FIG. 5), the vertical wall 112a of the valve body 112 is seated on the valve seat 111b. Then, the condensed water condensed in the condensing unit 110B is retained (held) in the space M on the outer peripheral side of the valve body 112, and the reflux of condensed water to the evaporation unit 110A is prevented. Thereafter, when the evaporation in the evaporation unit 110A proceeds, the steam flows into the condensing unit 110B through the hole 112b of the valve body 112, and the condensation in the condensing unit 110B continues. When evaporation in the evaporation unit 110A further proceeds, all of the water in the evaporation unit 110A evaporates into steam, and heat transport is stopped. That is, the exhaust heat recovery is stopped (right side of the time axis in FIG. 7), and the cooling water heating is stopped (exhaust heat recovery stop).

  Therefore, if the exhaust heat recovery is continued as the cooling water temperature rises with the passage of time after the engine 10 starts, the cooling water temperature rises too much, exceeding the heat dissipation capability of the radiator 20 and overheating. This failure can be prevented by switching to the exhaust heat recovery stop.

  Here, in the present embodiment, the valve body 112 that is closed by the thermostat 113 is provided in the heat pipe 110, and the space M is formed on the outer peripheral side of the valve body 112 when the valve is closed. Water is retained to prevent reflux to the evaporation unit 110A. Thus, in the heat pipe 110 when used as a bottom heat type, the heat transport operation and stop can be switched with the simple configuration as described above.

  Condensed water at the time of stopping heat transport is retained in the space M by the valve body 112, but the upper end position of the vertical wall portion 112a is set sufficiently higher (higher by a predetermined amount) than the surface of the condensed water to be retained. Therefore, it is possible to prevent the condensed water from dripping onto the evaporation unit 110A due to vibration of the vehicle or the like. That is, since rapid evaporation on the evaporation section 110A side can be prevented, there is no possibility that the internal pressure of the heat pipe 110 suddenly rises and the heat pipe 110 bursts or the heat pipe 110 is damaged due to repeated pressure fluctuations. .

  In addition, since the hole 112b is provided in the valve body 112, the vapor from the evaporation section 110A reaches the condensation section 110B through the hole 112b and is condensed even after the valve body 112 is closed. In addition, an increase in internal pressure in the evaporation unit 110A can be prevented.

  In addition, since the valve body 112 is opened and closed by the thermostat 113, the heat transport of the heat pipe 110 can be stopped based on the cooling water temperature.

(Second Embodiment)
A second embodiment of the present invention is shown in FIGS. 2nd Embodiment simplifies the structure of 112 A of valve bodies with respect to the said 1st Embodiment. That is, in the technique described in Patent Document 1 described in the section of the prior art, a temperature sensor and a valve means are used to stop the operation of heat transport by a heat pipe. It is considered that a control means that opens and closes the valve means according to the temperature of the valve is also required, and there is a problem that the cost is high, so that dripping of condensed water at the time of stopping heat transport is prevented while solving this problem .

  The container 111A of the heat pipe 110 is a sealed container whose upper end is also closed, and the thermostat 113 is abolished. The valve body 112A has a vertical wall portion 112a and a hole portion 112b formed in a disk-like portion, and the shaft 112c is eliminated. That is, the valve body 112A is freely disposed on the upper side of the valve seat 111b without support from other members.

  Further, the amount of water sealed in the heat pipe 110 is the amount that can completely evaporate in the evaporation section 110A when the exhaust gas temperature (exhaust heat amount) that rises according to the load of the engine 10 exceeds a predetermined exhaust gas temperature. Adjusted in advance.

  In the present embodiment, after the engine 10 is started, when the exhaust gas temperature accompanying the engine load is equal to or lower than the predetermined exhaust gas temperature, the vapor evaporated in the evaporation unit 110A rises and condenses through the hole 112b of the valve body 112A. Part 110B. At this time, the valve body 112A is lifted above the valve seat 111b by the upward steam flow (steam flow velocity) (the valve opened state in FIG. 8).

  The steam that has flowed into the condensing unit 110B is cooled by the cooling water flowing through the water tank 140, becomes condensed water at the inner wall surface 111a, descends due to gravity, and returns to the evaporation unit 110A along the inner wall surface 111a. Therefore, the cooling water is positively heated by the heat transport function of the heat pipe 110 (left side of the horizontal axis in FIG. 10, exhaust heat recovery operation).

  On the other hand, when the exhaust gas temperature associated with the engine load exceeds a predetermined exhaust gas temperature (with an increase in the amount of heat received by the evaporation unit 110A), all of the water in the evaporation unit 110A evaporates and there is no upward steam flow. The body 112A is seated on the valve seat 111b (the closed state of FIG. 8). Therefore, the condensed water condensed in the condensing unit 110B is retained in the space M on the outer peripheral side of the valve body 112A as in the first embodiment, and reflux of the condensed water to the evaporation unit 110A is prevented and heat transport is performed. Stopped (right side of horizontal axis in FIG. 10, exhaust heat recovery stopped).

  After that, when the operation of the engine 10 is stopped, the exhaust gas is not supplied to the evaporation unit 110A, so that the temperature of the evaporation unit 110A rapidly decreases. Further, since the cooling water has a large heat capacity, it maintains a high temperature (about 80 ° C.) for a while, so that the cooling water side (condensing part 110B) becomes the evaporation part of the heat pipe 110 and the exhaust gas side (evaporation part 110A) becomes It becomes a condensing part and the original operation is reversed. The condensed water retained in the space M gradually evaporates, passes through the hole 112b of the valve body 112A, condenses on the exhaust gas side (evaporating part 110A), and the heat pipe 110 returns to the original state.

  In the present embodiment, even if the cooling water temperature has not risen sufficiently, if the engine 10 once performs a high load operation and the exhaust gas temperature becomes higher than the predetermined exhaust gas temperature, the valve body 112A is moved to the valve seat 111b. There is a problem that it is difficult to return to the original state until the engine 10 is turned off once, but there is an advantage that it is much cheaper than the first embodiment.

  In this embodiment, the vertical wall portion 112a is provided on the outer peripheral side of the valve body 112A. However, the water retention function can be similarly secured even if the vertical wall portion 112a is provided around the hole portion 112b.

(Other embodiments)
In the said 2nd Embodiment, although 112 A of valve bodies were used as a holding means of condensed water, it may replace with this and may be used as an area expansion part which expands the inner wall surface area of the condensation part 110B. Specifically, the area enlargement portion can be a wick made of metal mesh, metal felt, foam metal, sintered metal, or the like, and the same effect as in the second embodiment can be obtained.

  Moreover, although the shape of the heat pipe 110 (container 111) is a circular tube, the shape is not limited to this, and may be a square tube, a flat tube, a multi-hole tube, or the like.

  Further, the exhaust pipe 11 as the high temperature part and the heater circuit 30 as the low temperature part have been described as transporting the heat of the exhaust gas to the cooling water, but the exhaust heat of other heat generating devices is used for heating the predetermined part. May be.

It is a schematic diagram which shows the mounting state to the vehicle of a waste heat recovery apparatus. It is a side view which shows the waste heat recovery apparatus in 1st Embodiment. It is sectional drawing in the AA part of FIG. It is sectional drawing which shows the valve body (valve open state) in the heat pipe in 1st Embodiment. It is sectional drawing which shows the valve body (valve closed state) in the heat pipe in 1st Embodiment. It is an arrow line view which shows the valve body seen from the B direction in FIG. It is a graph which shows the operating state and stop state of the heat transport function of a heat pipe with respect to cooling water temperature. It is sectional drawing which shows the valve body (valve open state) in the heat pipe in 2nd Embodiment. It is sectional drawing which shows the valve body (valve closed state) in the heat pipe in 2nd Embodiment. It is a graph which shows the heat transfer amount to the engine cooling water by the exhaust heat recovery apparatus in 2nd Embodiment.

Explanation of symbols

10 Engine (Internal combustion engine)
11 Exhaust pipe (high temperature part)
30 Heater circuit (low temperature part, cooling water flow path)
DESCRIPTION OF SYMBOLS 100 Waste heat recovery apparatus 110 Heat pipe 110A Evaporating part 110B Condensing part 111 Container (sealed container)
111a Inner wall surface (return channel)
112 Valve body (holding means)
112a Vertical hole (weir)
112b hole (flow passage)

Claims (9)

An evaporation section (110A) that is set on one end side of the tubular sealed container (111) and evaporates the internal working medium by the heat of the external high temperature section (11);
In the heat pipe having the condensing part (110B) that is set on the other end side of the closed container (111) and that condenses the working medium that is radiated and evaporated to the external low temperature part (30),
The evaporator (110A) is disposed below the condenser (110B),
A holding means (112) for holding the liquefied working medium condensed in the condensing unit (110B) and preventing recirculation to the evaporating unit (110A) as the amount of heat received in the evaporating unit (110A) increases. A heat pipe characterized by comprising: An evaporation section (110A) that is set on one end side of the tubular sealed container (111) and evaporates the internal working medium by the heat of the external high temperature section (11);
In the heat pipe having the condensing part (110B) that is set on the other end side of the closed container (111) and that condenses the working medium that is radiated and evaporated to the external low temperature part (30),
The evaporator (110A) is disposed below the condenser (110B),
Holding means (112) for holding the liquefied working medium condensed in the condensing part (110B) and preventing reflux to the evaporating part (110A) when the temperature of the low temperature part (30) exceeds a predetermined value. A heat pipe characterized by comprising:   The holding means (112) is provided between the evaporation section (110A) and the condensation section (110B), and is a valve body (112) that opens and closes the return flow path (111a) of the liquefied working medium. The heat pipe according to claim 1 or 2, characterized by the above. The valve body (112) includes a flow path (112b) through which the vapor working medium evaporated in the evaporation section (110A) flows,
The heat pipe according to claim 3, further comprising a weir portion (112a) for preventing the liquefied working medium from flowing out to the flow passage (112b) side.   The height of the dam portion (112a) is provided by a predetermined amount higher than the liquid level of the liquefied working medium that is prevented from flowing out to the flow passage (112b). Heat pipe.   The said valve body (112) is driven by the thermal expansion and thermal contraction of the thermowax (113) provided in the said condensation part (110B), Any one of Claims 2-5 characterized by the above-mentioned. Heat pipe as described in.   The heat pipe according to claim 1, wherein the holding means (112) is an area expanding portion that expands an inner wall surface area of the condensing portion (110B).   The heat pipe according to claim 7, wherein the area enlargement portion is a wick. The evaporation part (110A) of the heat pipe (110) according to claim 1 to 8 is disposed in an exhaust pipe (11) for exhaust gas circulation of the internal combustion engine (10),
The condensing part (110B) is disposed in a cooling water flow path (30) for circulating cooling water of the internal combustion engine (10),
An exhaust heat recovery apparatus using a heat pipe, wherein the exhaust heat of the exhaust gas is transported to the cooling water by the heat pipe (110).

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