JP2020044896A - Air conditioner for vehicle - Google Patents

Abstract

To improve the startability of a heat pipe system when its operation is restarted.SOLUTION: An air conditioner 1 includes: an exhaust pipe 3 for discharging exhaust gas generated in an internal combustion engine 2; and a heat pipe system 4 for recovering heat of the exhaust gas. The heat pipe system 4 includes: an evaporator 44 which is attached to the exhaust pipe 3 and evaporates a working medium R4 by heat exchange with the exhaust gas; a capacitor 43 for liquefying the working medium R4 evaporated in the evaporator 44; liquid piping 42 for conveying the working medium R4 liquefied in the capacitor 43 to the evaporator 44; gas piping 41 for conveying the working medium R4 evaporated in the evaporator 44 to the capacitor 43; and an opening/closing valve 45 provided in the liquid piping 42. The heat pipe system 4 further includes: a liquid accumulation part 46 which is provided in a part in the liquid piping 42 between the opening/closing valve 45 and the evaporator 44, and which passes through a position lower than a height h of a liquid piping inlet 44a of the evaporator 44; and promotion means for promoting liquid accumulation to the liquid accumulation part 46 during non-recovery of waste heat.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an air conditioner for a vehicle.

As a heat source for heating a vehicle driven by an internal combustion engine (engine), cooling water for the engine is exclusively used.
However, since the temperature of the cooling water is low in the early stage of the start of the internal combustion engine, it takes some time until the temperature in the vehicle compartment reaches a predetermined temperature by heating.

Patent Literature 1 discloses a heat pipe system for utilizing heat of exhaust gas as a heat source for heating a vehicle.
Patent Document 2 discloses a hot water supply device using a loop-type heat pipe.

JP-A-2-127511 Japanese Patent Publication No. 6-078871

  The heat pipe system disclosed in Patent Literature 1 includes an evaporator attached to an exhaust pipe of an internal combustion engine, a condenser provided in a duct through which air for air conditioning flows, and a liquid that sends a working medium liquefied by the condenser to the evaporator. There is provided a pipe and a gas pipe for sending the working medium evaporated by the evaporator to the condenser.

  In this heat pipe system, a working medium (liquid) is heated and vaporized by a high-temperature exhaust gas flowing through an exhaust pipe in an evaporator. In the condenser, the working medium in a gaseous state supplied through a gas pipe emits heat (condensation latent heat) to air for air conditioning flowing through the duct and is liquefied. Thereby, the air for air conditioning is heated by the condenser, and the vehicle interior is heated by the heated air for air conditioning.

The working medium liquefied in the condenser is sent to the evaporator via the liquid pipe. Then, the working medium in a liquid state in the evaporator is heated by the high-temperature exhaust gas flowing through the exhaust pipe, and is vaporized again.
In the heat pipe system, a part of the heat of the exhaust gas is effectively used for heating the air for air conditioning by circulating the working medium between the evaporator and the condenser while repeating a state change (cycle) ( Collected).

  In a loop type heat pipe (heat pipe system) provided in the hot water supply device of Patent Document 2, an on-off valve is provided in the middle of a liquid pipe connected to a condenser.

In the heat pipe system disclosed in Patent Document 2, the circulation of the working medium in the heat pipe system can be prevented by closing an on-off valve provided in the middle of the liquid pipe.
Thereby, the heat transport using the working medium in the heat pipe system can be stopped.

In a heat pipe system, when heat (exhaust heat) such as exhaust gas is not recovered (when exhaust heat is not recovered), the on-off valve is closed. However, when the on-off valve is closed, the on-off valve of the liquid pipe, the evaporator, The liquid medium is exhausted at the portion between the two.
When the operation of the heat pipe system is resumed by opening the on-off valve in such a state, a time delay occurs in the start of the heat pipe system because the liquid medium is not quickly sent from the liquid pipe to the evaporator, and the heat pipe system starts. In some cases, it became worse.

  There is a need to be able to enhance the startability of the heat pipe system when restarting operation.

The present invention
An exhaust pipe through which exhaust gas generated by the internal combustion engine flows,
A heat pipe system for recovering heat of the exhaust gas,
The heat pipe system comprises:
An evaporator attached to the exhaust pipe to evaporate a working medium by heat exchange with the exhaust gas;
A condenser for liquefying the working medium evaporated in the evaporator,
A liquid pipe for sending the working medium liquefied in the condenser to the evaporator,
A gas pipe that sends the working medium evaporated by the evaporator to the condenser,
An on-off valve provided in the liquid pipe,
A liquid reservoir provided at a position between the on-off valve and the evaporator of the liquid pipe and passing through a position lower than a liquid pipe inlet height of the evaporator;
And an accelerating means for accelerating the liquid pool when the exhaust heat is not collected in the liquid pool portion.

  ADVANTAGE OF THE INVENTION According to this invention, the startability at the time of operation restart of a heat pipe system can be improved.

It is a figure explaining the schematic structure of the air conditioner for vehicles. It is a figure explaining the basic composition of the air conditioner for vehicles. It is a figure explaining arrangement of a condenser, a liquid piping, and a gas piping in an air conditioner for vehicles. It is a figure explaining arrangement of an exhaust heat recovery machine, a liquid piping, and a gas piping in an air conditioner for vehicles. It is a figure explaining the liquid pool part of a heat pipe system. It is a figure explaining the modification of the promotion means which promotes the pool in the pool section. It is a figure explaining the modification of the promotion means which promotes the pool in the pool section. It is a figure explaining the modification of the promotion means which promotes the pool in the pool section. It is a figure explaining the modification of the promotion means which promotes the pool in the pool section.

Hereinafter, embodiments of the present invention will be described.
FIG. 1 is a diagram illustrating a schematic configuration of a vehicle air conditioner 1 according to the present embodiment.
FIG. 2 is a diagram illustrating a basic configuration of the air conditioner 1 for a vehicle, and is a diagram illustrating a circuit configuration of a heat pipe system 4, a refrigeration cycle 5, and a cooling water circulation cycle 6.
FIG. 3 is a diagram illustrating the arrangement of the condenser 43, the liquid pipe 42, and the gas pipe 41 in the vehicle air conditioner 1.
FIG. 4 is a diagram illustrating the arrangement of the exhaust heat recovery unit 35, the liquid pipe 42, and the gas pipe 41 in the vehicle air conditioner 1.
FIG. 5 is a diagram illustrating the liquid reservoir 46 of the heat pipe system 4. 5A is an enlarged view around the liquid reservoir 46, and FIG. 5B is a cross-sectional view taken along the line AA in FIG.

[Configuration of Air Conditioner 1]
As shown in FIG. 1, in the front part of the vehicle V, an air conditioner 1 is installed in front of a driver's seat 71 (to the left in FIG. 1).
An engine room in front of the firewall 72 of the vehicle V accommodates an internal combustion engine (ENG) 2 as a drive source.
The internal combustion engine 2 converts thermal energy generated by combustion of fuel such as gasoline into kinetic energy (driving force). An exhaust pipe 3 is connected to the internal combustion engine 2 as an exhaust system for exhaust gas generated by fuel combustion.

  The exhaust pipe 3 extends along the lower surface of the floor 74 toward the rear of the vehicle (to the right in FIG. 1). High-temperature exhaust gas generated by combustion of fuel in the internal combustion engine 2 flows through the exhaust pipe 3 toward the rear of the vehicle and is discharged into the atmosphere.

  In the middle of the exhaust pipe 3, a catalyst 31 for purifying exhaust gas, an exhaust heat recovery unit 35, and a muffler (not shown) that is a muffler are provided. In the exhaust pipe 3, the catalyst 31, the exhaust heat recovery unit 35, and the muffler are provided along the flow direction of the exhaust gas.

  The exhaust heat recovery unit 35 recovers a part of the heat of the exhaust gas. In the exhaust heat recovery unit 35, as shown in FIGS. 1 and 4, the exhaust pipe 3 branches into a forked shape to form a heat recovery path 32 and a bypass path 33.

The heat recovery path 32 and the bypass path 33 join at the downstream side in the flow direction of the exhaust gas and are connected to a downstream portion of the exhaust heat recovery unit 35 of the exhaust pipe 3.
As shown in FIG. 1, switching doors 34 a and 34 b are provided at the upstream branching portions of the heat recovery passage 32 and the bypass passage 33 and at the downstream merging portion, respectively, so as to be rotatable.

  The switching doors 34 a and 34 b are provided for selectively flowing the exhaust gas flowing into the exhaust heat recovery unit 35 from the catalyst 31 side to the heat recovery path 32 or the bypass path 33.

Here, FIG. 1 illustrates a case where the heat recovery path 32 and the bypass path 33 are arranged vertically, and the heat recovery path 32 is located above the bypass path 33. .
FIG. 4 illustrates a case where the heat recovery path 32 and the bypass path 33 are arranged side by side in the horizontal direction. The arrangement of the heat recovery path 32 and the bypass path 33 may be any of the modes shown in FIGS.

The heat recovery path 32 of the exhaust heat recovery device 35 is provided with an evaporator 44 that recovers a part of the heat of the exhaust gas by exchanging heat with the exhaust gas.
The evaporator 44 is a component of the heat pipe system 4 that recovers the heat of the exhaust gas to the working medium R4. In the vehicle air conditioner 1, the heat of the exhaust gas collected by the heat pipe system 4 is used for heating the air for air conditioning in the air conditioner 1.

As shown in FIG. 2, in addition to the heat pipe system 4, the air conditioner 1 includes a refrigeration cycle 5 used for cooling the air-conditioning air Air, and a cooling water circulation cycle 6 used for heating the air-conditioning air Air. have.
Inside the air conditioner 1, there is formed a duct 11 through which air for air conditioning flows.
Inside the duct 11, a sirocco fan 12, an evaporator 53, a heater core 63, a condenser 43, and an air mixing chamber 14 are provided in this order from the upstream side in the flow direction of the air Air in the duct 11. I have.

  The sirocco fan 12 (blower) is driven when the air conditioner 1 operates, and sucks air (inside air) inside the vehicle room 70 (see FIG. 1) and / or air (outside air) outside the vehicle room 70. The sirocco fan 12 sends out the sucked air to an evaporator 53 disposed downstream of the sirocco fan 12.

  In the evaporator 53, the air Air passing through the evaporator 53 is cooled and dehumidified by the heat of vaporization when the heat medium R5 evaporates.

A heater core 63 of the cooling water circulation cycle 6 is provided on the downstream side of the evaporator 53 in the flow direction of the air Air.
The heater core 63 heats the air Air passing through the heater core 63 by heat exchange with the cooling water R6 (heat medium) of the internal combustion engine 2.

The condenser 43 of the heat pipe system 4 is provided downstream of the heater core 63 in the flow direction of the air Air.
In the condenser 43, the air passing through the condenser 43 is heated by heat exchange with the working medium R4.

In the air conditioner 1, the condenser 43 is provided downstream of the evaporator 53 in the flow direction of the air flowing through the duct 11. A heater core 63 is arranged between the evaporator 53 and the condenser 43 and on the upstream side as viewed from the condenser 43.
In the air conditioner 1, the air Air that has passed through the heater core 63 passes through the condenser 43 as it is.

  The mix door 13 is provided between the heater core 63 and the evaporator 53. The mix door 13 is provided to adjust the amount of air that has passed through the evaporator 53 and flows into the heater core 63.

  When the mix door 13 is arranged at a position where the air that has passed through the evaporator 53 is prevented from flowing into the heater core 63 (see the phantom line in FIG. 3), the air that has passed through the evaporator 53 is supplied to the air mixing chamber 14 as it is. Is done.

  When the mix door 13 is disposed at a position where the air passing through the evaporator 53 is prevented from flowing into the air mixing chamber 14 (see the solid line in FIG. 3), the air Air passing through the evaporator 53 condenses with the heater core 63. Pass through the vessel 43 side. The air Air that has passed through the heater core 63 and the condenser 43 is finally supplied to the air mixing chamber 14.

  In the air conditioner 1, the amount of air passing through the heater core 63 is adjusted by a control device (not shown) changing the position of the mix door 13 according to the set temperature in the passenger compartment 70 and the like.

  In the air mixing chamber 14, the air Air cooled when passing through the evaporator 53 and the air Air heated while passing through the heater core 63 and the condenser 43 are mixed and adjusted to a desired temperature. .

  The air mixing chamber 14 has an inlet 15 on the differential duct side, an inlet 16 on the vent duct side, and an inlet 17 on the foot duct side. Each of the inlets 15, 16, 17 is provided with an on-off valve driven by a control device (not shown).

  The air Air that has flowed into the inflow port 15 is sent out from a differential air outlet (not shown) toward the front window of the vehicle V. The air Air that has flowed into the inflow port 16 is sent out from a vent outlet (not shown) toward the upper body of the occupant. The air Air that has flowed into the inflow port 17 is sent out from a foot outlet (not shown) toward the feet of the occupant.

  The air Air (air conditioning air) whose temperature has been adjusted in the air mixing chamber 14 is supplied to the passenger compartment 70 through at least one of the inlets 15, 16 and 17, and the interior of the passenger compartment 70 is air-conditioned. .

As shown in FIG. 2, the evaporator 53 involved in cooling the air Air is provided on a refrigerant pipe 50 provided in the refrigeration cycle 5. The refrigerant pipe 50 has a gas pipe 51 through which the heat medium R5 in a gas state flows, and a liquid pipe 52 through which the heat medium R5 in a liquid state flows.
The refrigeration cycle 5 has an expansion valve 54, a compressor 55, and a condenser 56 in addition to the evaporator 53.

The expansion valve 54 is provided in the liquid pipe 52 that connects the condenser 56 and the evaporator 53, and decompresses and expands the liquid-state heat medium R5 flowing through the liquid pipe 52.
The evaporator 53 evaporates the heat medium R5 supplied from the expansion valve 54 under reduced pressure.

The compressor 55 is provided in the gas pipe 51 that connects the evaporator 53 and the condenser 56, and sucks the heat medium R5 evaporated by the evaporator 53 and compresses the heat medium R5 to a high temperature and a high pressure.
The condenser 56 cools and condenses the high-temperature and high-pressure heat medium R5 supplied from the compressor 55 side through the gas pipe 51 by heat exchange with the outside air.

  In the refrigeration cycle 5, the heat medium R5 circulates between the evaporator 53 and the condenser 56 by the power of the compressor 55. When the heat medium R5 cooled by the condenser 56 absorbs heat when evaporated by the evaporator 53, the air Air flowing through the duct 11 is cooled and dehumidified.

The heater core 63 involved in the heating of the air Air is connected to a cooling path 60 provided in the cooling water circulation cycle 6 via a cooling water introduction pipe 61 and a cooling water outlet pipe 62.
The cooling path 60 has a first path 601 and a second path 602. The first path 601 is a circulation path in which the internal combustion engine 2, the radiator 67, the cooling water valve 64, and the water pump 66 are provided along the flow path of the cooling water. The radiator 67 is provided with a cooling water tank 65.

  The cooling water valve 64 may be of a type that switches to one of an open position and a closed position (a so-called on-off valve), or a type of which the opening degree can be adjusted by control (a flow control valve).

The second path 602 is connected to the downstream side of the internal combustion engine 2 and the upstream side of the water pump 66 in the flow direction of the cooling water in the first path 601. The second path 602 is a bypass that bypasses the radiator 67 and the cooling water valve 64.
A cooling water introduction pipe 61 and a cooling water outlet pipe 62 extending from the heater core 63 are connected to a second path 602.

In the cooling water circulation cycle 6, when the water pump 66 is driven with the cooling water valve 64 opened, the cooling water R6 flows through the first path 601 and the second path 602.
When the water pump 66 is driven with the cooling water valve 64 closed, the cooling water R6 flows through the second path 602.

The first path 601 is provided through the internal combustion engine 2, and the cooling water R <b> 6 is heated by the exhaust heat of the internal combustion engine 2 when passing through the area of the internal combustion engine 2, and Cooling.
Of the cooling water R6 heated by the exhaust heat of the internal combustion engine 2, the cooling water R6 passing through the first path 601 is cooled by heat exchange with the outside air when passing through the radiator 67.

  Part of the cooling water R6 passing through the second path 602 passes through the heater core 63 and circulates to the first path 601, and the remaining part circulates to the first path 601 without passing through the heater core 63.

In the heater core 63, the air Air is heated by performing heat exchange between the high-temperature cooling water R6 supplied from the cooling path 60 (second path 602) side and the air Air.
The cooling water R6 whose temperature has decreased due to heat exchange with the air Air is returned to the cooling path 60 (second path 602) via the cooling water outlet pipe 62.

The condenser 43 involved in heating the air Air is provided on the circulation path 40 (the gas pipe 41 and the liquid pipe 42) of the working medium R4 provided in the heat pipe system 4.
The circulation path 40 is formed by arranging a cylindrical tube made of a metal material in an annular shape and sealing the working medium R4 therein under reduced pressure.

  The heat pipe system 4 has a condenser 43 (internal condenser I / C) in addition to the evaporator 44 described above. The evaporator 44 and the condenser 43 are connected by a gas pipe 41 and a liquid pipe 42. An on-off valve (electromagnetic valve) 45 is provided in the liquid pipe 42.

In the evaporator 44, the working medium R4 in a liquid state (for example, water) is heated by heat exchange with the exhaust gas to evaporate.
The gas pipe 41 has a function of supplying the working medium R <b> 4 which has been evaporated to a gaseous state in the evaporator 44 to the condenser 43.

In the condenser 43, the working medium R 4 in a gaseous state is cooled and condensed by heat exchange with the air Air passing through the condenser 43.
The liquid pipe 42 has a function of supplying the working medium R4 condensed by the condenser 43 to a liquid state to the evaporator 44.

In the heat pipe system 4, the working medium R4 circulates between the evaporator 44 and the condenser 43 while repeating a state change (cycle) between gas and liquid.
In the heat pipe system 4, a part of the heat of the exhaust gas is recovered to the working medium R4 by heating the working medium R4 using the exhaust heat of the exhaust gas.
Then, since the air Air passing through the condenser 43 is heated by using the heat recovered in the working medium R4, the heat of the exhaust gas is effectively used.

  In the heat pipe system 4, when the on-off valve (electromagnetic valve) 45 provided on the liquid pipe 42 is closed, the circulation of the working medium R4 in the circulation path 40 is stopped. Thereby, the transportation of the heat recovered from the exhaust gas to the working medium R4 to the condenser 43 side is stopped.

As shown in FIG. 3, the gas pipe 41 penetrates the pipe connection part 310 and is drawn into the duct 11, and the tip of the gas pipe 41 is connected to the upper end of the side edge of the condenser 43. I have.
The liquid pipe 42 is also drawn into the duct 11 through the pipe connection part 310, and the tip of the liquid pipe 42 is connected to the lower end of the side edge of the condenser 43.

The gas pipe 41 and the liquid pipe 42 extending from the air conditioner 1 to the outside penetrate the firewall 72 of the vehicle V and reach the inside of the housing (engine room) of the internal combustion engine 2.
In the engine room, the gas pipe 41 and the liquid pipe 42 extend downward along the firewall 74 along the floor 74 side, and then extend rearward along the lower surface of the floor 74 to the vehicle V.

  The gas pipe 41 is connected to the upper part of the exhaust heat recovery unit 35 (evaporator 44) from the front side of the vehicle V (see FIG. 4).

  The liquid pipe 42 extends below the gas pipe 41 to the rear side of the vehicle V along the lower surface of the floor 74. The liquid pipe 42 is connected to the lower part of the evaporator 44 of the exhaust heat recovery unit 35 from the front side of the vehicle V.

  The liquid pipe 42 has an inner diameter smaller than that of the gas pipe 41. The liquid pipe 42 and the gas pipe 41 are supported via a bracket 18 in a region of the exhaust pipe 3 on the vehicle front side with respect to the catalyst 31.

  In the liquid pipe 42, an on-off valve 45 is provided on the evaporator 44 side of the area supported by the bracket 18. When viewed from the on-off valve 45, the bracket 18 is located on the upstream side in the flow direction of the working medium R4 in the liquid pipe 42.

  On the evaporator 44 side of the opening / closing valve 45 in the liquid pipe 42, a liquid pool portion 46 formed by bending the liquid pipe 42 is provided. The liquid reservoir 46 is formed by bending a cylindrical pipe.

As shown in FIG. 5, the liquid reservoir 46 has a first area 46a extending downward from a liquid pipe inlet 44a of the evaporator 44, and a first area 46a extending forward from the lower end of the first area 46a along the horizontal direction. It has a second region 46b and a third region 46c extending upward from the tip of the second region 46b.
The liquid pipe 42 extending from the on-off valve 45 to the vehicle rear side is connected to the upper end of the third region 46c.

The liquid pipe inlet 44a of the evaporator 44 is located on an extension of the liquid pipe 42, and the liquid reservoir 46 passes through a position lower than the height h of the liquid pipe inlet 44a of the evaporator 44 from the ground. It is provided.
When viewed from the side of the evaporator 44, the liquid reservoir 46 has a concave shape in which the range from the first region 46a to the third region 46c is depressed downward.

In the second region 46b of the liquid reservoir 46, a plurality of disk-shaped heat radiation fins 471 are provided at predetermined intervals in the longitudinal direction of the second region 46b.
The radiating fins 471 are provided in a region through which the traveling wind passes when the vehicle equipped with the air conditioner 1 is traveling, and are provided to cool the liquid working medium R4 in the second region 46b.

In the present embodiment, the plurality of radiating fins 471 provided in the second region 46b constitute "liquid pool accelerating means" in the present invention.
The plurality of radiation fins 471 cool the working medium R4 in the liquid reservoir 46 when the on-off valve 45 is closed and the exhaust heat recovery of the exhaust gas by the heat pipe system 4 is not performed (when the exhaust heat is not recovered). Then, it is provided to maintain the liquid state.

  That is, the plurality of radiating fins 471 are an embodiment of a cooling unit provided to prevent the working medium R4 accumulated in the liquid reservoir 46 of the liquid pipe 42 from evaporating when the exhaust heat is not recovered.

[Operation of air conditioner 1 for vehicle]
Next, the operation of the vehicle air conditioner 1 will be described.
When it is necessary to heat the interior of the vehicle room 70 of the vehicle V in winter or the like, the mix door 13 is arranged at a position indicated by a solid line in FIG.
Further, the switching doors 34a and 34b provided in the exhaust heat recovery unit 35 are set at the positions indicated by solid lines in FIG.

  At the initial stage of starting the internal combustion engine 2, the temperature of the cooling water R6 in the cooling water circulation cycle 6 is low. Therefore, even if the cooling water R6 flows through the heater core 63, the heater core 63 hardly contributes to heating.

  On the other hand, the temperature of the exhaust gas discharged from the internal combustion engine 2 is sufficiently high even at the initial stage of starting the internal combustion engine 2. Therefore, by using the heat of the exhaust gas collected by the heat pipe system 4 to heat the air Air supplied to the vehicle interior 70, the interior of the vehicle interior 70 can be heated from the initial start of the internal combustion engine 2.

  That is, in the heat pipe system 4, when the high-temperature exhaust gas discharged from the internal combustion engine 2 passes through the heat recovery path 32 of the exhaust heat recovery unit 35, the high-temperature exhaust gas passes through the evaporator 44 installed in the heat recovery path 32. Then, the working medium R4 in a liquid state is heated and evaporated (vaporized).

The working medium R4 (water vapor) which has been evaporated into a gaseous state by the evaporator 44 flows into the condenser 43 in the duct 11 through the gas pipe 41.
The working medium R4 in the gaseous state that has flowed into the condenser 43 is condensed by heat exchange with air-conditioning air (inside air or outside air) passing through the condenser 43.
In the condenser 43, the working medium R4 in a gaseous state emits latent heat of condensation into air for air conditioning to condense (liquefy). Thereby, the air for air conditioning is heated.

The working medium R4 (water) liquefied in the condenser 43 flows into the evaporator 44 provided in the exhaust heat recovery unit 35 through the liquid pipe 42.
The working medium R4 in a liquid state that has flowed into the evaporator 44 is heated again by the exhaust gas flowing through the heat recovery passage 32 in the exhaust heat recovery device 35 and evaporates (vaporizes), so that part of the heat of the exhaust gas is removed. Collect again.

  The working medium R4 circulates through the closed circuit (the circulation path 40) while repeating the state change (evaporation and liquefaction), so that part of the heat of the exhaust gas discharged from the internal combustion engine 2 is recovered, and the recovered heat is recovered. Thereby, the interior of the passenger compartment 70 is heated.

When a predetermined time has elapsed since the start of the internal combustion engine 2, the internal combustion engine 2 warms up and stabilizes at a predetermined temperature state (so-called warm time).
At that time, the temperature of the cooling water R6 becomes high (a temperature higher than room temperature, for example, 60 ° C. or more). Accordingly, in such a state, when air passes through the heater core 63 in which the cooling water is circulating, the heater core 63 radiates heat by exchanging heat with the cooling water, and the air is heated.

  When the temperature of the cooling water R6 rises after the internal combustion engine 2 is started, the high-temperature cooling water R6 flows into the heater core 63 through the cooling water introduction pipe 61, and then flows through the cooling water outlet pipe 62 to be cooled. Returned to path 60.

Here, in the heat pipe system 4, recovery and non-recovery of heat of the exhaust gas are selected by switching of the switching doors 34 a and 34 b provided in the exhaust heat recovery unit 35.
That is, when the switching doors 34a and 34b are at the positions shown by solid lines in FIG. 1, the exhaust gas flows through the heat recovery path 32 in the exhaust heat recovery unit 35 as described above, and a part of the heat of the exhaust gas evaporates. Is collected by the working medium R4 in the vessel 44.

  On the other hand, when the switching doors 34 a and 34 b are switched to the positions indicated by the broken lines in FIG. 1, the exhaust gas discharged from the internal combustion engine 2 to the exhaust pipe 3 And flows to the bypass path 33. Therefore, the heat of the exhaust gas is not recovered in the exhaust heat recovery unit 35.

  In the air conditioner 1 for a vehicle according to the present embodiment, the heater core 63 and the heat pipe system 4 are used together. However, if the heater core 63 alone can sufficiently provide heating, the operation of the heat pipe system 4 is performed. I'm trying to stop.

  Specifically, a control device (not shown) switches the switching doors 34a and 34b of the exhaust heat recovery unit 35 to the positions indicated by the broken lines in FIG. 1 so that the exhaust gas flows by bypassing the evaporator 44. Further, the on-off valve 45 is closed to stop the circulation of the working medium R4 in the circulation path 40.

However, even when the operation of the heat pipe system 4 is stopped and the heat of the exhaust gas is not recovered (when the exhaust heat is not recovered), it is actually possible to completely shut off the heat reception from the exhaust pipe 3 of the evaporator 44. Difficult.
Therefore, there is a problem that the cycle of the heat pipe system 4 becomes unstable because the working medium (liquid medium) in the evaporator 44 is vaporized by receiving some heat.

Further, when the on-off valve 45 is closed during non-recovery of exhaust heat, the working medium R4 at a portion between the on-off valve 45 of the liquid pipe 42 and the evaporator 44 evaporates by receiving heat, and the on-off valve 45 of the liquid pipe 42 The working medium R4 at a portion between the evaporator 44 and the evaporator 44 may be exhausted.
In such a state, when the operation of the heat pipe system 4 is restarted by opening the on-off valve 45, the working medium R4 is not quickly sent from the liquid pipe 42 to the evaporator 44, so that the start of the heat pipe system 4 is delayed. May occur.
Therefore, the startability of the heat pipe system 4 may be deteriorated.

  In the present embodiment, as shown in FIG. 4, a liquid reservoir 46 formed by bending liquid pipe 42 is provided at a position between open / close valve 45 of liquid pipe 42 and evaporator 44. . The liquid reservoir 46 has a concave shape passing through a position lower than the height h of the liquid pipe inlet 44a of the evaporator 44.

Therefore, when the on-off valve 45 is closed when the exhaust heat is not recovered, the working medium R4 in a liquid state is stored in the liquid reservoir 46 of the liquid pipe 42.
In the present embodiment, as the accumulating means (cooling means) for accumulating the working medium (liquid accumulating) in the liquid accumulating section 46, the liquid accumulating section 46 is disposed at a position where the traveling wind hits. The liquid pool 46 is effectively cooled by the traveling wind.

Further, a disc-shaped heat radiation fin 471 is provided in the second region 46b of the liquid reservoir 46, and the heat radiation fin 471 is also provided in a region through which the traveling wind passes when the vehicle equipped with the air conditioner 1 travels. Is provided.
Therefore, also by the radiation fins 471, the liquid reservoir 46 is effectively cooled.

As described above, when the liquid pool 46 is cooled by the traveling wind, the working medium R4 stored in the liquid pool 46 is also cooled, so that the working medium R4 in the liquid state is discharged from around the exhaust heat recovery unit 35. The vaporization due to the heat reception is suitably suppressed.
Therefore, the storage (liquid pool) of the working medium R4 in the liquid reservoir 46 is promoted, and the liquid state working medium R4 is held in the liquid reservoir 46.

In this state, when the on-off valve 45 is opened and the operation of the heat pipe system 4 is restarted, the working medium R4 in the liquid state remaining in the liquid reservoir 46 of the liquid pipe 42 is quickly sent to the evaporator 44.
Thus, the heat exchange between the exhaust gas in the evaporator 44 and the working medium R4 in the liquid state can be started immediately, so that the heat pipe system 4 starts without time delay.
Therefore, the startability of the heat pipe system 4 is improved.

In the present embodiment, as shown in FIG. 4, the bracket 18 is provided on the liquid pipe 42 on the upstream side of the on-off valve 45 (on the upstream side in the flow direction of the exhaust gas and the liquid refrigerant). The liquid pipe 42 is held by the exhaust pipe 3 via the bracket 18.
Therefore, in the liquid pipe 42, the region between the liquid pool portion 46 and the liquid pipe inlet 44 a of the evaporator 44 on the evaporator 44 side of the bracket 18 is not in direct contact with the exhaust pipe 3. Further, the liquid reservoir 46 is arranged at a position away from the bracket 18.

  Therefore, the heat of the exhaust gas flowing through the exhaust pipe 3 is less likely to be transmitted to the liquid reservoir 46 of the liquid pipe 42 via the bracket 18. Therefore, vaporization of the working medium R <b> 4 stored in the liquid reservoir 46 is more effectively prevented. Thereby, the storage (liquid pool) of the working medium R4 in the liquid pool portion 46 is promoted.

As described above, the vehicle air conditioner 1 according to the present embodiment has the following configuration.
(1) The air conditioner 1
An exhaust pipe 3 for discharging exhaust gas generated in the internal combustion engine 2;
A heat pipe system 4 for recovering heat of the exhaust gas.
Heat pipe system 4
An evaporator 44 attached to the exhaust pipe 3 and evaporating the working medium R4 by heat exchange with exhaust gas;
A condenser 43 for liquefying the working medium R4 evaporated by the evaporator 44;
A liquid pipe 42 for sending the working medium R4 liquefied by the condenser 43 to the evaporator 44;
A gas pipe 41 for sending the working medium R4 evaporated by the evaporator 44 to the condenser 43;
An on-off valve 45 provided in the liquid pipe 42.
A liquid reservoir 46 provided at a position between the on-off valve 45 of the liquid pipe 42 and the evaporator 44 and passing through a position lower than the height h of the liquid pipe inlet 44a of the evaporator 44;
An accelerating means for accelerating the liquid pool when the exhaust heat is not collected in the liquid pool section 46.

With this configuration, when the on-off valve 45 is closed at the time of non-recovery of exhaust heat, the liquid-state working medium R <b> 4 is stored in the liquid reservoir 46 of the liquid pipe 42.
Since the accelerating means promotes the storage (liquid pool) of the working medium in the liquid reservoir 46, the working medium R4 in a liquid state can be reliably stored in the liquid reservoir 46.
In this state, when the on-off valve 45 is opened and the operation of the heat pipe system 4 is restarted, the working medium R4 in the liquid state remaining in the liquid reservoir 46 of the liquid pipe 42 is quickly sent to the evaporator 44.
Thus, heat exchange between the exhaust gas in the evaporator 44 and the working medium R4 in a liquid state can be started immediately, so that the heat pipe system 4 can be started without time delay. Therefore, the startability of the heat pipe system 4 is improved.

The vehicle air conditioner 1 according to the present embodiment has the following configuration.
(2) The accelerating means is constituted by a cooling means for cooling the liquid reservoir 46.

With this configuration, even if the heat reception from the exhaust pipe 3 through which the exhaust gas flows cannot be completely shut off, the liquid pool 46 is cooled and the working medium stored in the liquid pool is cooled. The vaporization of R4 can be suppressed.
Thereby, the working medium R4 in a liquid state can be held in the liquid reservoir 46, so that the startability of the heat pipe system 4 when the on-off valve 45 is opened and the operation of the heat pipe system 4 is restarted can be improved.

The vehicle air conditioner 1 according to the present embodiment has the following configuration.
(3) The liquid pool 46 is cooled by disposing the liquid pool 46 at a position where the traveling wind hits when the vehicle equipped with the air conditioner 1 is running.

With this configuration, the working medium R4 in a liquid state can be held in the liquid reservoir 46, so that the startability of the heat pipe system 4 can be improved.
Note that a rectifying plate and an under cover for adjusting the flow of the traveling wind are provided below the vehicle body. The current plate and the undercover are provided to suppress the occurrence of turbulence at the lower part of the vehicle body and to suppress the running resistance due to the turbulence.
By using the flow straightening plate and the under cover to allow the traveling wind passing through the lower part of the vehicle body to actively pass through the area of the liquid reservoir 46, the liquid reservoir 46 can be cooled more effectively.
Therefore, the flow of air toward the liquid reservoir 46 may be formed in the lower part of the vehicle body by the rectifying plate and the under cover provided in the lower part of the vehicle body.

The vehicle air conditioner 1 according to the present embodiment has the following configuration.
(4) By providing a plurality of radiating fins 471 on the surface of the liquid reservoir 46 (the second region 46b), the surface area of the liquid reservoir 46 can be reduced to other parts of the liquid pipe 42 (parts other than the liquid reservoir 46). Was set larger than the surface area.

With this configuration, the surface area of the liquid reservoir 46 is increased, so that the liquid reservoir 46 can be cooled more effectively.
In the present embodiment, the case where the radiation fin 471 is provided in the second region 46b of the liquid reservoir 46 has been exemplified. The radiation fins 471 may be provided in other regions (the first region 46a and the third region 46c) of the liquid reservoir 46.

  In the present embodiment, water is exemplified as the working medium R4 that circulates through the heat pipe system 4. Any fluid other than water (for example, a chlorofluorocarbon-based refrigerant such as HFC) can be used as the working medium R4.

  FIGS. 6 to 9 are diagrams illustrating a modification of the accelerating means (cooling means) for accelerating the liquid pool (storage of the working medium R4) in the liquid pool part 46 of the liquid pipe 42.

FIG. 6 is a view showing another example of the accelerating means (cooling means) provided in the liquid reservoir 46A. 6A is a partial side view around the evaporator 44, FIG. 6B is an enlarged detailed view of a region A in FIG. 6A, and FIG. 6C is an enlarged sectional view taken along line BB in FIG. FIG.
In FIG. 6B, a part of the second region 46b of the liquid reservoir 46 on the left side in the drawing is cut away, and the second region 46b is shown in cross section.

In the liquid reservoir 46A shown in FIG. 6, a radiation fin 471A is provided on the outer periphery of the second region 46b along the longitudinal direction of the second region 46b.
The radiation fins 471A are provided in a direction along the vehicle front-rear direction (flow direction of traveling wind). A plurality of radiation fins 471A are provided at appropriate intervals over the entire circumference in the circumferential direction on the outer periphery of the second region 46b.

With this configuration as well, the surface area (radiation area) of the liquid reservoir 46 (the second region 46b) is increased, so that the liquid reservoir 46 is more effectively cooled by the traveling wind.
Thereby, the liquid pool (prevention of vaporization of the liquid medium) in the liquid pool section 46 is promoted.

FIG. 7 is a view showing another example of the accelerating means (cooling means) provided in the liquid reservoir 46B.
FIG. 7A is a partial side view around the evaporator 44, and FIG. 7B is an enlarged view of the AA cross section in FIG. 7A.

In the liquid reservoir 46B shown in FIG. 7, a radiation fin 471B is provided on the inner periphery of the second region 46b along the longitudinal direction of the second region 46b.
The radiation fins 471B are provided in a direction along the vehicle front-rear direction (flow direction of traveling wind). In the inner periphery of the second region 46b, a plurality of heat radiation fins 471B are provided at appropriate intervals over the entire periphery in the circumferential direction.
The radiation fins 471B are provided along the flow direction of the working medium R4 so as not to hinder the flow of the working medium R4 flowing through the second region 46b.

With this configuration, the contact area with the working medium R4 in the liquid reservoir 46 (the second region 46b) increases, so that when the liquid reservoir 46 is cooled by the traveling wind, the operation in the liquid reservoir 46 is activated. The medium R4 is cooled efficiently.
Thereby, the liquid pool (prevention of vaporization of the liquid medium) in the liquid pool section 46 is promoted.
Note that a configuration in which the mode of FIG. 7 is combined with the heat radiation fin 471 of FIG. 5 or the heat radiation fin 471A of FIG. 6 may be employed.

FIG. 8 is a view showing another example of the accelerating means (cooling means) provided in the liquid reservoir 46C.
FIG. 8 shows an enlarged view of the periphery of the evaporator 44 as viewed from the side.

  In the liquid reservoir 46C shown in FIG. 8, the outer diameter φD1 in the range from the first region 46a to the third region 46c is larger than the outer diameter φD2 of the liquid pipe 42 (the area other than the liquid reservoir 46C in the liquid pipe 42). (ΦD1> φD2).

With such a configuration, the surface area (radiation area) of the working medium R4 in the liquid reservoir 46C is larger than that of the liquid pipe 42. Therefore, when the liquid reservoir 46 is cooled by the traveling wind, the liquid reservoir 46 is cooled. The working medium R4 inside is efficiently cooled.
Thereby, the liquid pool (prevention of vaporization of the liquid medium) in the liquid pool section 46 is promoted.
Note that the configuration shown in FIG. 8 may be combined with the radiation fin 471 in FIG. 5, the radiation fin 471A in FIG. 6, and the radiation fin 471B in FIG.

  FIG. 9 is a diagram illustrating a liquid reservoir 46D according to a modified example, and shows an enlarged view of the periphery of the evaporator 44 as viewed from the side.

9 has a first region 46a extending obliquely downward from a liquid pipe inlet 44a of the evaporator 44, and a second region 46b extending obliquely upward from the lower end of the first region 46a. I have.
The liquid pipe 42 extending from the on-off valve 45 to the vehicle rear side is connected to the upper end of the second area 46b.

The liquid pipe inlet 44a of the evaporator 44 is located on the extension of the liquid pipe 42, and the liquid reservoir 46D is provided via a position lower than the height h of the liquid pipe inlet 44a of the evaporator 44. ing.
When viewed from the side of the evaporator 44, the liquid reservoir 46 is formed in a V-shape with the bending point P directed downward in the first region 46a and the second region 46b.

  The liquid reservoir 46D is also provided in a region through which the traveling wind passes when the vehicle equipped with the air conditioner 1 is traveling, and the liquid reservoir 46D (the first region 46a and the second region 46b) has a liquid state. The working medium R4 is cooled.

With this configuration as well, when the liquid reservoir 46D is cooled by the traveling wind, the working medium R4 in the liquid reservoir 46D is efficiently cooled.
Thereby, the liquid pool (prevention of vaporization of the liquid medium) in the liquid pool section 46D is promoted.

  The liquid reservoir 46D may have a configuration in which the above-described heat radiation fins 471, 471A, and 471B are combined. Further, the outer diameter of the portion of the liquid reservoir 46D may be larger than the outer diameter of the liquid pipe 42.

  It should be noted that the present invention is not limited to the embodiments described above, and that various modifications are possible within the scope of the claims and the technical idea described in the specification and the drawings. Of course.

DESCRIPTION OF SYMBOLS 1 Air conditioner 11 Duct 12 Sirocco fan 13 Mix door 14 Air mixing chamber 15, 16, 17 Inlet 18 Bracket 2 Internal combustion engine 3 Exhaust pipe 31 Catalyst 310 Pipe connection 32 Heat recovery path 33 Bypass paths 34a, 34b Switching door 35 Exhaust Heat recovery unit 4 Heat pipe system 40 Circulation path 41 Gas pipe 42 Liquid pipe 43 Condenser 44 Evaporator 44a Liquid pipe inlet 45 Open / close valve 46, 46A, 46B, 46C, 46D Liquid reservoir 46a First area 46b Second area 46c Third regions 471, 471A, 471B Radiation fins 5 Refrigeration cycle 50 Refrigerant pipe 51 Gas pipe 52 Liquid pipe 53 Evaporator 54 Expansion valve 55 Compressor 56 Capacitor 6 Cooling water circulation cycle 60 Cooling path 601 First path 602 Second path 61 Cooling water introduction Piping 62 Cooling water outlet pipe 6 The heater core 64 cooling water valve 65 the cooling water tank 66 water pump 67 radiator 70 cabin 71 driver seat 72 firewall 74 floors Air Air P bend point R4 working medium R5 heat medium R6 cooling water (heat medium)
V Vehicle h Height φD1 Outer diameter φD2 Outer diameter

Claims (7)

An exhaust pipe through which exhaust gas generated by the internal combustion engine flows,
A heat pipe system for recovering heat of the exhaust gas,
The heat pipe system comprises:
An evaporator attached to the exhaust pipe to evaporate a working medium by heat exchange with the exhaust gas;
A condenser for liquefying the working medium evaporated in the evaporator,
A liquid pipe for sending the working medium liquefied in the condenser to the evaporator,
A gas pipe that sends the working medium evaporated by the evaporator to the condenser,
An on-off valve provided in the liquid pipe,
A liquid reservoir provided at a position between the on-off valve and the evaporator of the liquid pipe and passing through a position lower than a liquid pipe inlet height of the evaporator;
An accelerating means for accelerating the liquid pool when the exhaust heat is not collected in the liquid pool section.   The vehicle air conditioner according to claim 1, wherein the promotion unit is configured by a cooling unit that cools the liquid pool.   The air conditioner for a vehicle according to claim 2, wherein the liquid reservoir is disposed at a position where the traveling wind is applied.   4. The air conditioner for a vehicle according to claim 2, wherein a surface area of the liquid reservoir is set to be larger than a surface area of another part of the liquid pipe.   The air conditioner for a vehicle according to claim 4, wherein a radiation fin is provided on an outer peripheral portion or an inner peripheral portion of the liquid reservoir.   The air conditioner for a vehicle according to claim 4, wherein a diameter of the liquid reservoir is set to be larger than a diameter of another part of the liquid pipe.   The air conditioner for a vehicle according to any one of claims 1 to 6, wherein a holding portion for fixing the liquid pipe to the exhaust pipe is disposed upstream of the on-off valve. apparatus.

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