JP2001074383A - Heat accumulator for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vacuum 'heat accumulator for vehicle' having high heat insulating performance and advantageous in cost in which heat insulating efficiency is enhanced by reducing convection due to temperature difference of engine-cooling water and heating is allowed during manufacture of a container by eliminating a resin part. SOLUTION: An inner container 13 is contained in an outer container 11 through a vacuum heat insulating space 12 and the inlet and outlet pipes 5, 6 of the inner container 13 are provided to pass through the outer container 11. High temperature engine-cooling water introduced from the inlet pipe 5 is stored in the inner container 13 and delivered from the outlet pipe 6. In such a heat accumulator for vehicle, at least one of the inlet or outlet pipe 5, 6 in the vacuum heat insulating space 12 is provided with means H for preventing heat loss due to convection when the engine-cooling water is standing in the pipe 5 or 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a regenerator for a vehicle in which high-temperature engine cooling water for preheating an engine is stored.

[0002]

2. Description of the Related Art In general, it is effective for a vehicle to preheat an engine in order to improve emission control at the time of cold start and to improve immediate warming. There are various methods for preheating the engine. Recently, a method using engine cooling water has been frequently used. This method
When the engine cooling water is in a high temperature state, it is stored in advance in the regenerator and taken out at the next cold start.
It leads to the engine and heats the engine.

[0003] Therefore, it is important for the heat accumulator to store a constant volume of engine cooling water with high heat retention, and a vacuum heat insulation type heat accumulator is used for high heat retention.

That is, in this heat storage device, a vacuum heat insulating space is provided between the inner container and the outer container, so that heat held by the high-temperature engine cooling water stored in the inner container is prevented from escaping to the outside as much as possible. are doing.

[0005] However, the heat accumulator must have a rigidity capable of withstanding a high vacuum state in the heat insulating space, and is preferably lightweight for mounting on a vehicle.

For this reason, a conventional heat storage device is configured, for example, as shown in FIGS. FIG. 8 is a side view showing a conventional vehicle heat storage device, and FIG. 9 is a cross-sectional equivalent view taken along line 9-9 in FIG.

This heat storage device has a cylindrical shape as a whole, and a bead 11a is formed in the outer container 11 itself. The inner container 13 has a predetermined space between the outer container 11 and the outer container 11. Is supported by the suspension S so as to hold the heat insulating space 12 (Japanese Patent Laid-Open No.
139996, JP-A-4-217790, etc.). Here, the suspension S is
It is made of a leaf spring material.

In this regenerator, the amount of heat radiation from the heat-insulated space 12 in a high vacuum state is small and does not cause much problem, but the amount of heat radiation at the entrance and exit pipes 5 and 6 cannot be ignored. A header section 7 made of resin is provided at an end of the container 13, and the outlet pipe 6 and the inlet pipe 5 are connected to the header section 7. In this case, heat transfer due to heat transfer is less than in the connection between metals, the assembly is easy, and the cost is advantageous.

[0009]

However, when manufacturing this heat accumulator, not only the both lids 16a and 16b but also the header 7 are made of resin.
The getter method and the baking method used for forming the vacuum heat insulating space 12 cannot be used, and the method of applying a high vacuum is limited. In addition, because different materials exist partially,
There is also a problem that manufacturing is troublesome.

[0010] The heat radiation by the heat transfer in the regenerator used for such a purpose is not only caused by the heat transfer by the contact between the metals and the heat radiation by the radiant heat, but also by the convection due to the temperature difference of the engine cooling water in the inlet / outlet pipe. It has been found that heat escape also occurs by doing so.

That is, in the inlet / outlet pipe of the regenerator, when a part of the inlet / outlet pipe decreases in temperature, a difference in specific gravity occurs in the engine cooling water, thereby causing convection in the pipe, and the convection causes heat transfer to reduce the temperature. It turned out that the phenomenon of being promoted could not be ignored.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and it is an object of the present invention to reduce the generation of convection due to the temperature difference of engine cooling water, to enhance the heat insulation efficiency, and to eliminate the resin part. Accordingly, it is an object of the present invention to provide a vacuum-type heat regenerator for a vehicle which enables heating at the time of manufacturing a container, has high heat retention performance, and is advantageous in cost.

[0013]

The object of the present invention is achieved by the following means.

(1) The inner container is housed in the outer container via a vacuum insulated space, and the outlet tube and the inlet tube of the inner container are provided through the outer container, and the high temperature introduced from the inlet tube is provided. In the vacuum heat insulation type vehicle heat storage device that stores the engine cooling water in the inner container and flows out from the outlet pipe as needed, at least the outlet pipe or the inlet pipe existing in the vacuum heat insulating space. On the other hand, a convection preventing means for preventing heat loss due to convection when the engine cooling water in the pipe is stored is provided.

(2) The convection preventing means is characterized in that at least one of the outlet pipe and the inlet pipe existing in the vacuum insulating space is formed by a U-shaped curved portion extending the pipe vertically in the direction of gravity. Heat storage for vehicles.

(3) The heat storage device for a vehicle, wherein the outlet pipe or the inlet pipe is attached to a lower part of the outer container.

(4) The vehicle, wherein the convection preventing means is provided with a check valve provided in an outlet pipe or an inlet pipe existing in a vacuum insulated space to suppress the movement of the engine cooling water by convection. For heat storage.

(5) In the check valve, a valve element lighter than the specific gravity of the engine cooling water is provided at the outlet pipe, and a valve element heavier than the specific gravity of the engine cooling water is provided at the inlet pipe. A heat storage device for a vehicle, comprising:

[0019]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic diagram of a hot water circulation system provided with a vehicle heat accumulator according to an embodiment of the present invention, FIG. 2 is a side view of the vehicle heat accumulator, and FIG. 3 is a line 3-3 in FIG. FIG.

The heat storage device for a vehicle according to the present embodiment is provided in a circulation system for circulating engine cooling water of the vehicle as shown in FIG. This circulating system connects a water pump WP and a radiator R provided in the engine E to a thermostat 1.
A first closed circuit C1 connected to the heater core 2 through the first closed circuit C1 connected to the heater core 2 through the first closed circuit C1 and the first closed circuit C2.
A third closed circuit C3 which is communicated with the closed circuit C1 and guides a part of the circulating engine cooling water to the vehicle heat storage 10 via the inlet pipe 5 having the on-off valves 3 and 4 and the outlet pipe 6; I have.

As shown in FIG. 3, the vehicle heat storage device 10 has an outer container 11 and an inner container 13 housed in the outer container 11 via a vacuum heat insulating space 12. As shown in FIG. 2, the inner and outer containers 11 and 13 are formed so that the cross section perpendicular to the axis is substantially rectangular so as to be easily accommodated in the engine room. Note that the heat insulating space 12 is formed so as to exist over the entire outer surface of the inner container 13.

The outer container 11 has two lids 14a, 14b.
, And the body 15, which are 0.3 to 0.5 m
It is made of stainless steel, aluminum, or the like, which is an extremely thin metal having a low thermal conductivity of about m.
The outer container 11 may have a number of concave bead portions 15a formed on the body portion 15 in order to increase the rigidity of the outer container 11 itself. The same applies to the inner container 13.

On the other hand, the inner container 13 has two lids 16a, 1
6b and a body portion 17, which are also the outer container 1
It is made of the same material as 1 except that a plurality of partition plates 18 are provided inside.

The partition plate 18 is provided so as to partition the inside of the inner container 13 in a zigzag manner so that the engine cooling water flowing from the inlet pipe 5 reaches the outlet pipe 6 as a so-called one-way flow. However, since it is provided extending from one end to the other end of the body 17, it also has a function of reinforcing the inner container 13.

In particular, in the present embodiment, first, the above-mentioned resin header is not provided, and the lid is made of metal.
Second, the inlet pipe 5 and the outlet pipe 6 are connected to the lid 1 of the outer container 11.
4a is inserted directly into the lid 1 of the inner container 13 after the insertion.
The inlet pipe 5 is provided with a means (hereinafter referred to as convection preventing means) H for preventing heat loss due to convection of the flowing engine cooling water.

First, regarding the first point, if the header portion and the like are not made of resin, the entire heat storage unit 10 can be made of metal, and means for heating the whole can be used during manufacture. Using the getter method (a method in which the getter metal is heated in a vacuum, and the inside of the getter metal is vacuumed while the interior is beautifully brilliant) or a baking method (a method in which the whole is heated and evacuated). A high vacuum heat insulating space of 10 ^-5 torr or less can be secured. Accordingly, the degree of vacuum does not decrease due to the fine particles remaining in the heat insulating space 12, and high heat insulating performance due to the high degree of vacuum can be exhibited.

As for the second point, when the engine cooling water flows into the inner container 13 through the inlet pipe 5, the on-off valves 3 and 4 are closed and stored therein. Is transmitted through the inlet pipe 5 and the like during storage to escape to the outside. As a result, the temperature of the engine cooling water near the inlet pipe 5 decreases, causing a partial difference in specific gravity. This causes convection, heat is transferred, and the temperature of the engine cooling water further decreases. For this reason, in the present embodiment, the convection preventing means H is applied to the inlet pipe 5 in the heat insulating space 12.

More specifically, the convection preventing means H is shown in FIG.
As shown in FIG. 5, a U-shaped curved portion 19 is formed in the inlet pipe 5 in the heat insulating space 12 so as to extend the inlet pipe 5 up and down in the direction of gravity.

That is, if the bellows portion J is formed in the inlet pipe 5 existing in the heat insulating space 12 and is bent into a U-shape, the length of the inlet pipe 5 becomes longer and the heat conduction becomes longer due to the longer path. It is difficult to be transmitted, and the heat retention is improved.

When the temperature of the engine cooling water in the inlet pipe 5 decreases due to the heat conduction, the specific gravity of the lowered engine cooling water increases. When the temperature of the engine cooling water drops, this heavy water lump L descends along the external inlet pipe 19a and accumulates at the lower end of the external inlet pipe 19a, as shown in FIG. Similarly, the heavy water mass R having a lowered temperature in the inner inlet pipe 19b on the right side of the curved portion 19 is connected to the inner inlet pipe 19b.
b, and accumulates at the lower end of the internal inlet pipe 19b. As a result, the left and right ends of the curved portion 19 are closed by the heavy water masses L and R, so that the movement of water due to convection in the curved portion 19 is eliminated, and escape of heat is prevented.

Further, when the inlet pipe 5 having the U-shaped curved portion 19 is attached to the lower portion of the outer container 11, the curved portion 19 can be formed from the lower portion to the upper portion, so that the entire heat storage device 10 is unnecessary. There is also an advantage that the size is not increased.

The convection preventing means H can be constituted by forming a U-shaped curved portion 19 in the inlet pipe 5, but check valves 20 and 23 as shown in FIG. 4 may be used.

FIG. 4 is a sectional view showing another embodiment of the convection preventing means H. The convection preventing means H is provided with a check valve 20 on the outer inlet pipe 19a side of the curved portion 19 of the inlet pipe 5. As shown in FIG. 5, the check valve 20 is provided so that a guide rod 20b is attached to a spherical valve body 20a having a specific gravity higher than that of water to open and close the opening 22 in order to prevent convection. The opening 22 is opened when water flows in, but is normally closed to prevent convection.

In this way, the movement of water is controlled by the check valve 20.
Therefore, the movement of water due to convection in the curved portion 19 is eliminated, and the escape of heat is more reliably prevented.

It is preferable to provide a check valve 23 also on the outlet pipe 6 side. However, as shown in FIG. 6, the check valve 23 has a stopper 23c attached to a spherical valve body 23a having a specific gravity lower than that of water via a guide rod 23b.
The opening 24 is opened when engine cooling water flows out, and is normally closed to prevent convection.

The check valve 20 is preferably formed of a metal hollow body, but the check valve 23 is not necessarily a hollow body but may be a solid metal body. In this way, the entire heat accumulator 10 is made of metal, and a high-vacuum insulated space can be formed by using a baking method or the like in which the entire heat accumulator is heated during manufacturing.

In order to maintain the high vacuum state in the heat insulating space 12, the outer container 11 or the inner container 13 is required.
It is sufficient to increase the rigidity of the container itself, but this increases the thickness of each container, which is not preferable in terms of weight. In this embodiment, as shown in FIG. The first rib R1 protrudes from the outer surface of the inner container 13 to the second rib R1.
It is preferable that the ribs R2 protrude so that the tips of the ribs R make point contact. These ribs R are provided so as to cross each other at right angles or to cross each other diagonally.

Each of the ribs R has a thickness of 0.3 to 0.5.
The above-mentioned baking method and the like can be used without any problem if they are made of a metal made of stainless steel, aluminum, or the like having a length of about mm and made of an L-shaped or T-shaped angle material.

The inner and outer containers 11,
If the inner and outer containers 11 and 13 are rectangular or box-shaped or have a thin wall thickness of about 0.3 mm, the reinforcing member 13 has sufficient pressure resistance to vacuum. As a result, the overall weight can be reduced, which is preferable as an in-vehicle component.

Next, the operation of the embodiment will be described.

First, when forming the heat storage device 10 for a vehicle, the lid 16a to which the inlet pipe 5 and the outlet pipe 6 are attached is attached to the body 17 by welding or brazing. Attach the base end side of the second rib R2.

Next, in a state where the first rib R1 is placed on the inner container 13 so as to cross the second rib R2, the first rib R1 is placed in the outer container 11 having one end closed and the other end opened. Then, the lid 14a through which the inlet pipe 5 and the outlet pipe 6 pass is brought into contact.

The cover 14a is provided with a suction port (not shown) in advance.
The air in the chamber 2 is exhausted while being sucked, and the lid 14a is heated and joined to the outer container 11 while maintaining the degree of vacuum. In this case, since the heat accumulator 10 is entirely made of metal, a getter alloy may be put in the heat insulating space 12 and baked at the time of vacuum suction to remove harmful gas remaining inside. A metal may be vapor-deposited on the inner surface or the like of the inner container 13 to reflect radiant heat from water.

The vehicle heat storage device 1 thus formed
No. 0 is used by connecting the inlet pipe 5 and the outlet pipe 6 to the third closed circuit C3 via the on-off valves 3 and 4. In use, at the time of normal operation, when the temperature of the engine cooling water becomes high, the opening / closing valve 3 on the inlet side and the opening / closing valve 4 on the outlet side are opened, and the engine cooling water flowing through the circulation system is taken into the inner container 13. .

The engine cooling water flows in from the inlet pipe 5, flows in a zigzag manner in the inner container 13 partitioned by the partition plate 18, and flows out from the outlet pipe 6. At the moment when the cooling water is stored, the on-off valve 3 on the inlet side and the on-off valve 4 on the outlet side are closed,
The engine cooling water is sealed and stored in the inner container 13.

In this case, the heat held by the engine cooling water is insulated by the heat insulating space 12.
This also prevents heat loss.

That is, when the temperature of the engine cooling water in the inlet pipe 5 decreases, the specific gravity of the engine cooling water increases,
The heavy water lump L in the outer inlet pipe 19a descends and accumulates at the lower end portion, and the heavy water lump R having a lowered temperature in the inner inlet pipe 19b.
Also accumulate at the lower end. As a result, the left and right ends of the curved portion 19 are closed by the heavy water bodies L and R, so that the movement of water due to convection in the curved portion 19 is eliminated, and escape of heat is prevented.

When the check valves 20 and 23 are provided, even if the temperature of the engine cooling water drops in the inlet pipe 5 and the specific gravity increases, the check valves 20 and 23 prevent the cooling water from descending. In particular, the position where the heavy water mass accumulates is determined by the check valves 20 and 23.
, The prevention of water movement by convection starts at an early point in time after the temperature of the engine cooling water starts to decrease, and the prevention of heat escape also starts early.

When the engine is started when the outside temperature is low, for example, in winter, the engine cooling water is circulated in the circulation system by the water pump WP driven at the same time as the start of the engine. In this state, the on-off valves 3 and 4 are opened to return the high-temperature engine cooling water stored in the inner container 13 to the circulation system, and the engine is heated via the engine cooling water.

The present invention is not limited to the above-described embodiments, but can be variously modified and used within the scope of the claims. In the above-described embodiment, the U-shaped curved portion 19 is formed on the inlet pipe 5 side as the convection preventing means H, but the curved portion 19 may be provided on the outlet pipe 6 side. The inlet pipe 5 and the outlet pipe 6 may each be formed with only the curved portion 19.

[0052]

According to the first aspect of the present invention, at least one of the outlet pipe and the inlet pipe in the vacuum heat insulating space of the vehicle heat storage device is provided with a means for preventing convection of the engine cooling water. Reduces the generation of convection, enhances adiabatic efficiency, and stores high-temperature engine cooling water for a long period of time. Further, since convection can be prevented in the inlet / outlet pipe, the temperature drop of the engine cooling water does not spread to the inside, so that high-temperature engine cooling water can be stored for a long time. Furthermore, since the resin-made header can be eliminated, heating at the time of manufacturing the container is possible, and a higher-vacuum regenerator can be obtained, which can also improve the heat retention performance. In addition, it is advantageous in terms of cost because the number of parts is reduced.

According to the second aspect of the present invention, since the entrance / exit tube itself is curved in a U-shape to serve as the convection preventing means, the heat transfer distance becomes longer, the heat transfer becomes more difficult, and the convection due to the temperature difference of the engine cooling water is generated. And the overall insulation efficiency can be increased, and the number of components is small, the configuration is simplified,
This is advantageous in cost.

According to the third aspect of the present invention, since the outlet pipe or the inlet pipe having the U-shaped curved portion is attached to the lower portion of the outer container, the curved portion can be formed from the lower portion to the upper portion, which is unnecessary. The entire heat storage unit does not become large.

According to the fourth aspect of the present invention, since a check valve is provided in the inlet / outlet pipe to serve as a convection preventing means, a convection preventing function is quick and a heat storage device having a high heat retaining performance can be obtained.

According to a fifth aspect of the present invention, the check valve on the outlet pipe side comprises:
The valve element lighter than the specific gravity of the engine cooling water and the check valve on the inlet pipe side are each provided with a valve element heavier than the specific gravity of the engine cooling water. The convection prevention function is quick and it becomes a heat storage with high heat retention performance.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a hot water circulation system provided with a vehicle heat storage device according to an embodiment of the present invention.

FIG. 2 is a side view of the vehicle heat storage device.

FIG. 3 is a cross-sectional equivalent view taken along line 3-3 in FIG.

FIG. 4 is a sectional view showing another embodiment of the present invention.

FIG. 5 is a sectional view showing a check valve on the inlet pipe side.

FIG. 6 is a sectional view showing a check valve on the outlet pipe side.

FIG. 7 is a perspective view illustrating a ridge member.

FIG. 8 is a side view showing a conventional vehicle heat storage device.

9 is a cross-sectional equivalent view taken along line 9-9 in FIG.

[Explanation of symbols]

 5 ... Inlet pipe, 6 ... Outlet pipe, 10 ... Vehicle regenerator, 11 ... Outer vessel, 12 ... Insulated space, 13 ... Inner vessel, 19 ... Bending part, 20,23 ... Check valve, 20a, 23a ... Valve Body, H: Convection prevention means.

Claims (5)

[Claims] An inner container (13) is housed in an outer container (11) via a vacuum insulating space (12), and an outlet pipe (6) and an inlet pipe (5) of the inner container (13) are connected. The outer vessel (11) is provided so as to pass therethrough, and the high-temperature engine cooling water introduced from the inlet pipe (5) is stored in the inner vessel (13).
(6) A vacuum heat-insulating vehicle heat storage device that is allowed to flow out from (6), wherein at least one of the outlet pipe (6) or the inlet pipe (5) present in the vacuum heat-insulating space (12) is connected to the pipe ( A heat storage device for a vehicle, further comprising a convection preventing means (H) for preventing heat loss due to convection when the engine cooling water in (5, 6) is stored. 2. The convection preventing means (H) connects the pipe (5, 6) to at least one of the outlet pipe (6) or the inlet pipe (5) existing in the vacuum heat insulating space (12) in the direction of gravity. U extending up and down
The heat accumulator for a vehicle according to claim 1, wherein the heat accumulator is constituted by a curved portion (19). 3. The heat storage device according to claim 2, wherein the outlet pipe (6) or the inlet pipe (5) is attached to a lower portion of the outer container (11). 4. The non-return means for suppressing convection of the engine cooling water in an outlet pipe (6) or an inlet pipe (5) existing in a vacuum heat insulating space (12). Valve (20,2
The vehicle heat accumulator according to any one of claims 1 to 3, wherein 3) is provided. 5. The check valve (20, 23) is connected to the outlet pipe (6).
The valve element (23a) which is lighter than the specific gravity of the engine cooling water
The heat storage device for a vehicle according to claim 4, wherein the inlet pipe (5) is provided with a valve element (20a) that is heavier than the specific gravity of the engine cooling water.