JPH0435208Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a heat exchanger for vehicle heating, and in particular, a heat exchanger for vehicle heating in which the heat exchange cylinder is formed of silicon carbide to improve heat exchange performance. Concerning vessels.

[Conventional technology]

Heating in vehicles equipped with an engine is generally an important issue, and especially in winter, after a cold start of the engine, the heating will not work for about 5 to 10 minutes, so drivers should wear warm clothes. If you wear light clothes and get into the vehicle, you will have to take them off, and if you get in the vehicle wearing light clothing, you will have to put up with the cold at first.To avoid this, warm up the vehicle thoroughly before driving. There were issues such as whether it was necessary.

Therefore, if there were a device that could blow hot air for heating into the interior of a car in about 5 to 10 seconds, comfort in winter or in cold regions would be greatly improved.

Therefore, a combustion device and a heat exchanger device are installed in the intake passage of the engine. Immediately after the engine starts, the combustion device is ignited, and the heat is used to warm the air in the heat exchanger, and the warm air is transferred into the vehicle interior. However, in such devices, the performance of the heat exchanger is important, and there is a problem in that there are very few heat exchangers that can be used for this purpose.

That is, as a heat exchanger that can be used for the above purpose, for example, Japanese Patent Application Laid-Open No. 57-58085 and Japanese Patent Application Laid-Open No. 57-57
There is a heat exchanger shown in Japanese Patent Publication No. 175881, etc., and the one in Japanese Patent Application Laid-open No. 57-58085 has passages on the outside, inside, and in the middle, and heat exchange between the outside and inside is performed by an intermediate fluid medium. In addition, the method of JP-A-57-175881 aims to improve heat exchange performance by having heat conductive surfaces alternately intersecting from the inside and outside. Either of these is unsuitable as a heat exchanger for use in the intake passage. This is because castings have poor narrow path formability and poor thermal conductivity, and aluminum castings have poor heat resistance.

In addition, Utility Model Publication No. 41-7777 proposes a heat exchanger, but this one has fins between cylinders with a triple structure, and because it is made entirely of metal, it is high temperature. As a heat exchanger for passing combustion gas, it has low heat resistance and lacks durability due to its complicated structure.

On the other hand, Japanese Patent Publication No. 59-46496 proposes the use of silicon carbide, which has high thermal conductivity and excellent heat resistance, as the main material for heat exchangers.
However, it is extremely difficult to manufacture sintered heat exchangers using silicon carbide with high precision.
Due to its shape, it has been difficult to obtain a heat exchanger that has high strength, high precision, and does not cause gas leakage.

[Purpose of invention]

The purpose of this invention is to provide a heat exchanger that uses silicon carbide for the parts that come into contact with high-temperature combustion gas, and uses a high-strength, high-precision fired product for the main part (the main body of the heat exchanger). This heat exchanger improves the indoor heating performance immediately after a cold start of a vehicle, and provides a heat exchanger for heating a vehicle that has excellent heat resistance and durability.

That is, the present invention provides an excellent vehicle heating heat exchanger that can be installed in an intake passage, can withstand high-temperature heat from an upstream combustion device, and has good heat exchange performance.

[Structure of the idea]

The vehicle heating heat exchanger according to the present invention for achieving the above object includes a combustion burner 8 in the intake passage 2 of the engine 1 and a vehicle heating heat exchanger 10 downstream of the combustion burner 8. , this heat exchanger 1
0 includes a first cylinder 11, a second cylinder 12 arranged concentrically on the outer periphery of the first cylinder 11, and a third cylinder 13 in which a heating air passage 18 is formed on the outer periphery of the second cylinder 12. A thin tube portion 13b is formed by reducing both ends of the third cylinder 13, and this thin tube portion 13b is fitted into the second cylinder 12 via a sealing material 30, and a flange 13a is provided at the end. The cylinder 12 has a partition wall 14 radially projecting in the longitudinal direction so as to contact the outer surface of the first cylinder 11 on its inner surface, and a heat transfer surface 16 radially projecting into the heating air passage 18 made of silicon carbide. It is integrally molded by.

It is known that silicon carbide is used for the main body of a heat exchanger due to its heat resistance, but silicon carbide is formed into the shape of the main body of a cylindrical heat exchanger with many fins and then dried. In many cases, it is difficult to deform and maintain a predetermined shape, but the present invention clearly solves this problem.

〔Example〕

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

FIG. 3 is a configuration diagram of a vehicle heating system showing the installation location of the vehicle heating heat exchanger of the present invention, in which 1 is an engine, 2 is an intake manifold, 3 is an air cleaner, and 4 is an intake pipe.

In the middle of the intake pipe 4, a fuel supply device 7 including a heater, a vaporization device 8 for vaporizing the fuel in this fuel supply device 7, and an ignition device 9 are provided. The heat exchanger 10 of the present invention is installed on the downstream side of the intake pipe 4. The fuel supply device 7 of the fuel vaporization device 8 is connected to a fuel pump 6 attached to the engine 1 via a flow control valve 27,
Further, the ignition device 9 is connected to a battery 28 via a switch 29. The hot air outlet 15 of the heat exchanger 10 is connected to the heater main body 2 of the air conditioner 20 via a duct 25 via the blower fan 5.
Connected to 1. 22 is a heater core to which the cooling water of the engine 1 is guided through a hot water pipe 23; 24 is a cooling device; 26 is a blower; 29 is a switch for the ignition device 9; 32 is a heating switch; 31 is a switch linked to the switch 32; 33 is a fuel supply device 9
36 is a cooling water temperature sensor for the engine 1, and 40 is a control device.

The vehicle heating heat exchanger 10 of the present invention, which is arranged in the above position, has a shape as shown in FIGS. 1 and 2. That is, the heat exchanger 10 of the present invention is composed of three concentric cylinders: a first cylinder 11 which is the innermost cylinder, a second cylinder 12 which is the middle cylinder, and a third cylinder 13 which is the outermost cylinder. ing.

The first cylinder 11 is a hollow cylinder, and a passage 11a is provided inside the first cylinder 11. Second cylinder 12
is provided with a partition wall 14 on the inner surface of the cylinder that reaches the first cylinder 11 and extends in the longitudinal direction of the cylinder, and a lattice-shaped space 17 surrounded by the first cylinder 11, the second cylinder 12, and the partition wall 14. serves as a passage for combustion gas, and the outer surface of the second cylinder 12 is provided with a pleated heat transfer surface 16. This second cylinder 12 is made of silicon carbide having high thermal conductivity (thermal conductivity=0.3 cal/cmsec).

The reason for using silicon carbide is as follows. In other words, automotive heating systems require a lightweight and compact heat exchanger, and for this purpose it is effective to increase the temperature of the heat exchange gas and to use materials with excellent thermal conductivity. It is. Silicon carbide is a material that meets this purpose, and even when exposed to high-temperature gas, it does not oxidize and corrode like aluminum.

However, when manufacturing this fired body mainly composed of silicon carbide, a material mainly composed of silicon carbide is molded into a predetermined shape, dried, and then sintered. In order to manufacture a sintered body, it is necessary to mold it into an accurate shape and then dry it while maintaining that shape.

To this end, partition walls 14 (fins) are formed radially on the inner surface of the second cylinder 12, and heat transfer surfaces 16 are formed radially on the outer surface thereof. Second cylinder 1
The partition wall 14 and the second cylinder 12 are formed by molding the partition wall 14 and the second cylinder 12 into such a shape, and drying the partition wall 14 and the second cylinder 12 by inserting a portion corresponding to the first cylinder 11 in contact with the inner edge of the partition wall 14. can hold its shape accurately. As shown in the cross section of FIG. 2, the heat exchanger of the present invention can be produced by sintering a molded body consisting of the second cylinder 12, the partition wall 14 integrated therein, and the heat transfer surface 16. The main parts can be completed.

Further, the third cylinder 13 is connected to the first cylinder 11 and the second cylinder.
It is a housing made of metal such as SUS that encloses a cylinder 12, and both ends thereof are reduced to form thin tube portions 13b, and each end thereof is provided with a flange portion 13a connected to the intake pipe 4. A sealing material 30 such as a carbon gasket is interposed between the narrow tube portion 13b and the end of the second cylinder 12 to provide a gas seal between the combustion gas and the heating air. is bulged out so that a space exists between it and the tip of the pleated heat transfer surface 16 of the second cylinder 12, thereby forming a heating air passage 18.

And the heating air passage 1 of the third cylinder 13
A heating hot air outlet 15 connected to the duct 25 is provided on the upstream side of the duct 8, and a heating air intake port 19 is provided on the downstream side.

In the vehicle heating heat exchanger of the present invention configured as described above, when the engine 1 is started, the switch 33 is turned on and fuel from the fuel pump 6 enters the fuel supply device 7. The fuel is heated by a heater in the fuel supply device 7, then enters the vaporization device 8 and is vaporized. At the same time, the switch 29 is turned on and the ignition device 9 is activated, and the fuel is combusted and becomes a high-temperature gas. .

When the flow rate of this high-temperature combustion gas is low, it mainly passes through the passage 11a having a large area and passes through the first passage 11a.
The heat is transmitted from the cylinder 11 to the partition wall 14, the second cylinder 12, and the heat transfer surface 16, and heats the air passing through the heating air passage 18. On the other hand, in the lattice-shaped space 17 surrounded by the second cylinder 12 and the partition wall 14, a low-temperature boundary layer is formed on the wall surface, increasing the flow resistance and reducing the flow rate of the combustion gas passing through the lattice-shaped space 17. Become. Therefore, when the flow rate of combustion gas is small, the heat flow is transferred from the inner wall to the outer wall of the passage 11a as described above.

Conversely, when the flow rate of high-temperature combustion gas increases, the temperature of the first cylinder 11, the partition wall 14, etc. increases, the boundary layer between the combustion gas and the wall becomes smaller, and heat transfer becomes easier, and the passage inside the first cylinder 11 increases. 11a and this first
A lattice-like space 17 between the cylinder 11 and the second cylinder 12
can pass through the entire surface, effectively increasing heat conduction and flow rate.

The combustion gas that has passed through the heat exchanger and radiated heat in this manner then flows into the engine to improve the startability of the engine.

At the same time as the heating switch 32 is turned on, the control device 4
When the switch 31 is turned on by 0, the blowing fan 5 rotates. Then, the air inside the heat exchanger 10 is sucked out, so that the air that has flowed into the heating air passage 18 from the air intake port 19 flows into the second cylinder 12.
The flow flows while touching the heat transfer surface 16 protruding from the hot air outlet 15, and the temperature rises to cause the hot air to flow from the hot air outlet 15 to the duct 25.
The air flows into the heater main body 21 of the air conditioner 20 and is supplied to the interior of the vehicle.

Note that if combustion gas is not allowed to pass through the passage 11a in the first cylinder 11 when the engine 1 is started, the amount of heat exchange between the combustion gas and the second cylinder 12 will increase, but during normal operation, the If the passage 11a is sealed, the intake resistance will increase, so an on-off valve is provided in the first cylinder 11, and the engine 1
By closing this when starting the engine and opening it during normal operation, it is possible to prevent an increase in the heat exchange rate when starting the engine and a decrease in suction efficiency during normal operation.

In this way, warm air for indoor heating can be obtained by the vehicle heating heat exchanger of the present invention immediately after the engine is started, so warm air is supplied to the driver even when the vehicle is operated immediately after a cold start. will be
Improves driving comfort during cold seasons and in cold regions.
This has the effect of leading to safer driving and reducing the number of accidents.

When the coolant temperature of the engine 1 rises, the sensor 36 detects this and inputs the signal to the control device 40, so the control device 40 stops the operation of the heat exchanger 10 of the present invention and blows air. The heater core 22 is activated to heat the interior of the vehicle using the heat of the heater core 22.

[Effect of idea]

The vehicle heating heat exchanger according to the present invention includes a combustion burner 8 in the intake passage 2 of the engine 1, and a vehicle heating heat exchanger 10 provided downstream of the combustion burner 8. A first cylinder 11, a second cylinder 12 arranged concentrically on the outer periphery of the first cylinder 11, a third cylinder 13 in which a heating air passage 18 is formed on the outer periphery of the second cylinder 12, Thin tube portion 1 formed by reducing both ends of the third cylinder 13
3b, and this thin tube portion 13b is fitted into the second cylinder 12 via a sealing material 30, and a flange 13a is provided at the end, and the second cylinder 12 has its inner surface in contact with the outer surface of the first cylinder 11. A partition wall 14 projecting radially in the longitudinal direction and a heat transfer surface 16 projecting radially into the heating air passage 18 are integrally formed of silicon carbide, and the It can be effective.

A: Low-temperature intake air is heated within a short period of time, improving engine startability and warm-up performance, and also dramatically improving indoor heating performance immediately after engine startup, improving driving comfort. .

B Since the second cylinder 12, partition wall 14, and heat transfer surface 16 are integrally formed of silicon carbide to have a specific cross-sectional shape as described above,
It is possible to produce a silicon carbide molded body that prevents deformation of partition walls 14 for forming lattice-like spaces 17 for heat exchange while uniformly dispersing combustion gas, and by firing this molded body, A sintered body having the desired shape can be obtained, and the heat exchanger assembled into the above structure using this sintered body has excellent heat resistance and heat exchange performance, and is an excellent heat exchanger for vehicle heating. can be provided.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the vehicle heating heat exchanger of the present invention, and Fig. 2 is a cross-sectional view of the vehicle heating heat exchanger of the present invention.
FIG. 3, a local cross-sectional view taken along the line, is a configuration diagram of a vehicle heating system showing the installation position of the vehicle heating heat exchanger of the present invention. 1...Engine, 2...Intake manifold, 3...
...Air cleaner, 4...Intake pipe, 5...Blowout fan, 6...Fuel pump, 7...Fuel supply device, 8
... vaporizer (combustion burner), 9 ... ignition device,
10... Heat exchanger, 11... First cylinder, 12...
2nd cylinder, 13...3rd cylinder, 14... partition wall,
15... Hot air outlet, 16... Heat transfer surface, 17...
...grid space, 18... heating air passage, 19...
...Air intake, 20...Air conditioner, 25...
Duct, 26...Blower, 27...Flow control valve,
27...Flow control valve, 30...Seal material, 32...
...heating switch.

Claims (1)

[Scope of Claim for Utility Model Registration] A combustion burner 8 is provided in the intake passage 2 of the engine 1, and a heat exchanger 1 for vehicle heating is provided downstream of the combustion burner 8.
0, and this heat exchanger 10 includes a first cylinder 11 and a second cylinder 12 arranged concentrically around the outer periphery of the first cylinder 11.
Furthermore, a third cylinder 13 in which a heating air passage 18 is formed on the outer periphery of this second cylinder 12, and a thin tube portion 13b formed by reducing both ends of this third cylinder 13.
Then, this thin tube portion 13b is fitted into the second cylinder 12 via the sealing material 30, and a flange 1 is attached to the end.
3a, and the second cylinder 12 has a partition wall 14 on its inner surface that projects radially in the longitudinal direction so as to contact the outside surface of the first cylinder 11, and a heat wall that projects radially into the heating air passage 18. A heat exchanger for heating a vehicle, in which a transmission surface 16 and a transmission surface 16 are integrally molded from silicon carbide.