WO2003099595A1

WO2003099595A1 - Heating system and exchanging device of dual heater

Info

Publication number: WO2003099595A1
Application number: PCT/KR2003/001007
Authority: WO
Inventors: Yun-Hyung Kim
Original assignee: Yun-Hyung Kim
Priority date: 2002-05-23
Filing date: 2003-05-22
Publication date: 2003-12-04
Also published as: KR20030090343A; AU2003232646A1; KR100446665B1

Abstract

The present invention provides a heating system for internal combustion engine comprising an engine, a cabin heater to heat the cabin of the vehicle using the cooling water for the engine; a cooling water collecting line through which the cooling water flows from the engine to the cabin heater; a cooling water supply line through which the cooling water flows from the cabin heater to the engine, wherein the heating system further comprises the heat exchanger according to the one of the claim 1 to 7; the first by-pass line connecting the cooling water collecting line and the first opening; the second by-pass line connecting the second opening and cooling water collecting line; water pumps for the free heater and air heater that are respectively installed on the first by-pass line and the second by-pass line, and send the cooling water to the heat exchanger; and a check valve that is installed between the first by-pass line and the second by-pass line and blocks the flow form the second by-pass line to the first by-pass line.

Description

HEATING SYSTEM AND EXCHANGING DEVICE OF DUAL HEATER

TECHNICAL FIELD

The present invention relates to a heating system and exchanging device of dual

heater

BACKGROUND OF THE INVENTION

Generally, the cabin of the vehicles, construction vehicles, ships and airplanes

which are powered by the internal combustion engine, use the heat of the cooling water for

the heating that circulates within the engine to cool the engine

But it is impossible to heat the cabin immediately after the engine starts, because

the temperature of the cooling water is low. The cabin can not be heated until the cooling

water is heated to a certain temperature.

For example, it usually takes 10 minutes to heat the cooling water to the desired

temperature that enables to heat the cabin of the passenger vehicle in winter, and it will

take more time in a hard winter.

The engine usually has low combustion efficiency in cold temperature and

discharges the exhaust gas that contains many toxic gases, so some people idle the engine

for the warming-up or heating the cabin. The amount of the toxic gases of the exhaust gas

in the idling is more than in the running the vehicle, so idling the engine may pollute the air with exhaust fumes severely.

So, it is prohibited to idle the engine more than certain time(about 2 minutes) in

some countries. But, it is impossible to heat the cabin and to warm-up the engine for the

time.

To solve above problems, the separate air-heater is developed that can heat the

cabin without the heat of the cooling water. The air heater uses burner that consumes less

fuel than the engine for heating the heat exchanger, the cold air is heated in the heat

exchanger, and then the heated air is deliver into the cabin. But, the air heater has a

problem that it can't warm-up the engine.

With the air heater, user must idle the engine and run the air heat simultaneously,

which increase the amount of the fuel consumption.

SUMMARY OF THE INVENTION

Therefore, it is an object of the present invention to provide a separate heating

system that can heat the cabin and warm-up the engine simultaneously, and that is

connected to the cooling water circulating line.

And, it is another object of the present invention to provide a heat exchanger that

can transfer the heat generated by the burner to the cold air via cooling water quickly and

efficiently.

To accomplish the objects of the present invention, there is provided a heat exchanger which comprises a burner to which the fuel is supplied directly from the fuel

tank; a cylindrical inner wall that forms a combustion chamber and connected to the end of

the burner; a cylindrical outer wall that is installed concentrically with the inner wall with

some distance from the outer face of the inner wall, forms a water jacket together with the

inner wall, and include the first opening and the second opening through which the cooling

water of the engine passes; an air duct that is installed with some distance from the outer

face of the outer wall, and one end of which is connected to the outside air and the other

end of which is connected to the air vent of the vehicle cabin; an air damper installed in the

air duct; and a fan installed between the burner and the air damper.

The heat exchanger of the present invention forms the water jacket around the

combustion chamber of the burner, and flows the cold air on the outer face of the water

jacket. So, the heat generated from the fuel heats the cooling water first, and the cold air is

heated by the heated cooling water. The heat exchanger of the present invention can heat

the cooling water and cold air simultaneously, which enables rapid cabin heating and

engine warm-up with the engine stopped.

Preferably, the inner wall can be formed by connecting plural ring-shaped heat

transfer members longitudinally, and one end of the inner wall can be closed by the arch-

shaped diffuser. Thus the inner wall can be manufactured more easily and the heat transfer

efficiency can be increased, because the exhaust gas flows again through the inner wall

after discharged from the burner. The heat transfer member that forms the inner wall has a flange in inner face that

is curved in the direction of the exhaust gas flow. It can increase the combustion efficiency

more to form such flange that acts as a heat transfer fin.

And, it is preferred to form plural swirl inducing holes on the perpendicular face

of the flange through which the exhaust gas is discharged in the tangential direction to the

inner wall. By the swirl inducing holes, the exhaust gas flows through the inner wall and

swirls, which increases the heat transfer efficiency.

Plural heat transfer fins can be formed radially on the outer face of the heat

transfer member.

And, the outer wall can be formed by connecting plural ring-shaped heat transfer

members longitudinally, and one end of the outer wall can be closed by the sealing plate.

Thus the outer wall can be manufactured more easily.

Plural heat transfer fins can also be formed radially on the outer face of the heat

transfer member for the outer wall to increase the heat transfer efficiency.

Also, there is provided a heating system for internal combustion engine

comprising an engine, a cabin heater to heat the cabin of the vehicle using the cooling

water for the engine; a cooling water collecting line through which the cooling water flows

from the engine to the cabin heater; a cooling water supply line through which the cooing

water flows from the cabin heater to the engine, wherein the heating system further

comprises the heat exchanger according to the one of the claim 1 to 7; the first by-pass line connecting the cooling water collecting line and the first opening; the second by-pass line

connecting the second opening and cooling water collecting line; water pumps for the free

heater and air heater that are respectively installed on the first by-pass line and the second

by-pass line, and send the cooling water to the heat exchanger; and a check valve that is

installed between the first by-pass line and the second by-pass line and blocks the flow

form the second by-pass line to the first by-pass line.

Moreover, there is provided a heating system for in internal combustion engine

comprises the heat exchanger according to the one of the claim 1 to 7; the first by-pass line

connecting the cooling water collecting line and the first opening; the second by-pass line

connecting the second opening and cooling water collecting line; the third by-pass line the

connects the first by-pass line and the second by-pass line; a water pump that is installed

on either of the first by -pass line and the second by -pass line, and send the cooling water to

the heat exchanger; a 3-way solenoid valve that is installed on the by-pass line on which

the water pump is not installed, and connected to the third by-pass line; and a check valve

that is installed between the first by-pass line and the second by-pass line and blocks the

flow form the second by-pass line to the first by -pass line. BRIEF DESCRIPTION OF THE DRAWINGS

The above objects and other advantages of the present invention will become

more apparent by detailed describing preferred embodiments thereof with reference to the

attached drawings in which:

Fig. 1 to 3 are the systemic diagrams to show the installing state of an

embodiment of dual heating system according to the present invention; wherein

Fig. 1 is for the cabin heating state,

Fig. 2 is for the engine warm-up,

Fig. 3 is for the cabin heating and engine warm-up.

Fig. 4 is the systemic diagram of another embodiment of dual heating system

according to the present invention;

Fig. 5 is the cross sectional view of an embodiment of the heat exchanger

according to the present invention;

Fig. 6 is the perspective view of the heat transfer member that forms the inner

wall of the water jacket;

Fig. 7 is the plane view of the embodiment in Fig. 6;

Fig. 8 and Fig. 9 are the cross sectional views according to the line A-A and B-B

in Fig. 7;

Fig. 10 is the perspective view of the heat transfer member that forms the outer wall of the water jacket;

Fig. 11 is the cross sectional view according to the line C-C in Fig. 10;

Fig. 12 is the cross sectional view of another embodiment of the heat exchanger

according to the present invention.

for the reference number in the Figures

1 : Dual heating system 2a, 2b, 2c : The first, second and third by-pass

line

3 : Dual heater heat exchanger 4 : water pump for free heater

4a : water pump 5 : water pump for the air heater

5a : 3-way solenoid valve 6 : air duct

7 : burner 8 : heat exchanging pass

10 : engine 11 : cabin heater

12 : cooling water supply line 13 : cooling water collecting line

21 : check valve 31 : inner wall of water jacket

311 : heat transfer member 312 : the first heat transfer fin

313 : the second heat transfer fin314 : swirl inducing hole

315 : gap 316 : swirl pass

317 : flange 32 : cylindrical body in rear end

33 : combustion chamber 34 : outer wall for the water jacket 341 : heat discharging member 342 : heat discharging fin

341a : heat discharging member in the front end

341b : heat discharging member in the rear end

35 : water jacket 35a, 35b : the first and second opening

36 : cylindrical body in the front end

37 : discharging tube 38 : sealing plate of combustion chamber

39 : diffusing plate 61 : induction tube for atmosphere air

62 : discharging tube for heated air

63 : air damper 71 : induction hole for combustion air

72 : induction fan for atmosphere air

73 : combustion cylinder

EMBODIMENTS

Hereinafter, preferred embodiments of the present invention will be described in

more detail with reference to the accompanying drawings, but it is understood that the

present invention should not be limited to the following embodiments.

Fig. 1 to 3 are the systemic diagrams to show the installing state of an

embodiment of dual heating system according to the present invention, Fig. 4 is the

systemic diagram of another embodiment of dual heating system according to the present invention, Fig. 5 is the cross sectional view of an embodiment of the heat exchanger

according to the present invention, Fig. 6 is the perspective view of the heat transfer

member that forms the inner wall of the water jacket, Fig. 7 is the plane view of the

embodiment in Fig. 6, Fig. 8 and Fig. 9 are the cross sectional views according to the line

A-A and B-B in Fig. 7, Fig. 10 is the perspective view of the heat transfer member that

forms the outer wall of the water jacket, Fig. 11 is the cross sectional view according to the

line C-C in Fig. 10, and Fig. 12 is the cross sectional view of another embodiment of the

heat exchanger according to the present invention.

The reference number 1 is indicating the dual heating system 1 that can be applied

to the cooling water circulation line to cool the engine for the motor vehicles, ships,

airplanes or construction machinery.

And the dual heating system 1 is installed on the cooling water collecting line 13,

as shown in Fig. 1 to 3, through which the heated cooling water by the heat transfer with

the engine 10 flows. The cooling water is supplied into the engine 10 to cool the engine 10,

and flows in the cooling water circulation line that consists of the engine 10, a cabin heater

11 that heats the cabin using the heat of the engine 10, a cooling water supply line 12 that

supplies the cooling water into the engine and a cooling water collecting line 13 through

which the heated cooling water flows from the engine 10 to the cabin 11.

The dual heating system 1 comprises the first and second by-pass line 2a, 2b that

are connected individually to the cooling water collecting line 13, and dual heater heat exchanger 3 that heats the cooling water flowing through the first or second by-pass line.

And, the dual heating system 1 further comprises a water pump 4 for free heater

and a water pump 5 for the air heater that are respectively installed on the first and second

by-pass line 2a, 2b, and a check valve 21 that is installed on the cooling water collecting

line 13 between the first and second by-pass line 2a, 2b.

The dual heater heat exchanger 3 of the dual heating system 1 comprises an air

duct 6 that forms a heat exchanging pass 8 on the outer face of the dual heater heat

exchanger 3 through which the cold air flows, an induction tube 61 for the atmosphere air

connected to the one end of the air duct 6, a discharging tube 62 for the heated air

connected to the another end of the air duct 6, and a burner 7 installed in the dual heater

heat exchanger.

An air damper 63 for controlling the induction of the atmosphere air is installed

inside of the one end of the air duct 6, and an inlet hole 71 for supplying the combustion air

and induction fan 72 for inducing the atmosphere air through the induction tube 61 and

send the air to the outer face of the dual heater heat exchanger 3 are installed between the

burner 7 and air damper 63, wherein the induction fan 72 can be powered by the power of

the motor installed on the burner or the additional power supply.

The dual heating system 1 according to the present invention can be constructed

as shown in Fig. 4. The embodiment in Fig. 4 includes a water pump 4a that pumps the

coolmg water to the first by-pass line 2a. In the second by-pass line 2b, 3-way solenoid valve 5a that changes the flow direction of the cooling water by a control device(ex.

electronic control unit of the vehicle) is installed. And the embodiment in Fig. 4 further

includes the third by-pass line 2c that connects the first by-pass line 2a in which the water

pump 4a is installed and the 3-way solenoid valve 5a.

Next, the constructions of the dual heater heat exchanger will be described.

The water jacket inner wall 31 of the dual heater heat exchanger 3 is made by

brazing plural heat transfer members 311 connected to each other to form a cylindrical

shape, and each heat transfer members 311 has a ring shape with 'C shape cross section.

And the water jacket inner wall 31 includes the cylindrical body 32 in rear end which is

welded to the open end of small diameter part 321.

Each heat transfer member 311 that forms the water jacket inner wall 31 includes

the first heat transfer fins 312 which are protruded toward inside of the combustion

chamber 33, the second heat transfer fins 313 which are protruded radially toward inside of

the water jacket 34, and plural swirl induction holes 314 arranged in the first heat transfer

fins 312 circumferencely.

The center hole of the first heat transfer fins 312 is curved rearward, and there are

plural gaps 315 and swirl passes 316 between adjacent the first heat transfer fins 312. Each

of the swirl induction hole 314 is formed by two protruding pieces 317, 318 each of which

is cut and bent in opposite direction to form a hole. Thus each of plural swirl induction holes 314 inclines in same direction(clockwise of counter-clockwise).

And, the both ends of the second heat transfer fins 313 are bent respectively in

opposite direction. That is, all of the second heat transfer fins 313 have same cross-section

of "^" shape.

The outer wall 34 of water jacket of the dual heater heat exchanger 3 is formed by

brazing plural heat discharge member 341 connected to form a cylindrical shape, which

has bigger diameter than the outer diameter of the second heat transfer fins 313. And each

heat discharge member 341 has plural heat discharge fins 342 in its outer edge each of

which is protruded outward. All of the heat discharge fins 342 are bent in same direction to

have " ^ " shape.

The heat discharge fins 341a, 341b in front end and rear end are longer in

longitudinal direction than the other heat discharge fins 341, the first tube 35a is welded

next to the heat discharge fins 341a in front end, and the second tube 35b is welded next to

the heat discharge fins 341b in rear end.

Both ends of the inner wall 31 and outer wall 34 of the water jacket is sealed and

individually connected. For the rear end, the large diameter part 322 of the cylindrical body

32 that is welded to the rear end of the inner wall 31, is welded heat discharge member

341b in the rear end of the outer wall 34 to connect both walls. For the front end, the heat

transfer member 311 positioned in the front end of the inner wall 31 is welded to the heat

discharge member 341a in the front end of the outer wall 34. For the connection, the heat transfer member 311 positioned in the front end of the inner wall 31 has a welding flange

317 in its outer face which is welded to the inner face of the heat discharge member 341a

in the front end of the outer wall 34.

And, the front end cylindrical body 36 is welded to the front end of the dual heater

heat exchanger 3, and a discharging tube 37 is formed in the front end cylindrical body 36

to discharge exhaust gas.

In the front end cylindrical body 36 of the dual heater heat exchanger 3, the burner

7 is installed, and the combustion cylinder 73 of the burner 7 is inserted into the

combustion chamber 33 by 1/3 of the entire length of the combustion chamber 33. The

sealing plate 38 of the combustion chamber is welded in the small diameter part 321 of the

rear end cylindrical body 32, and the diffusing plate 39 is mounted on the inner face of the

sealing plate 38 by bolt or rivet.

The diffusing plate 39 is curved steel plate, and diffuse the combusting heat of the

burner 7 to the first heat transfer fins 312 of the inner wall 31, the gaps 315 and swirl

passes 316 made by the first heat transfer fins 312.

Another embodiment in Fig. 12 of the dual heater heat exchanger 3 according to

the present invention has water jacket 35 which consists of the cylindrical inner wall 31a of

the water jacket with smaller diameter and the cylindrical outer wall 34a of the water

jacket with bigger diameter. The inner wall 31a has plural heat transfer fins 312a only in the inner face that are protruded inside of the combustion chamber 33, and the outer wall

34a has plural heat discharge fins 342a only in the outer face that are protruded toward the

air duct 8, wherein the heat transfer fins 312a and heat discharge fins 342a extends

straightly to the longitudinal direction of the inner wall and outer wall.

Hereafter, the operation of the dual heater heat exchanger will be described.

For the embodiment in Fig. 5 to 11, the combustion flame from the combustion

cylinder 73 inserted into the combustion chamber 33 heats the combustion chamber 33 by

igniting the burner 7. The combustion flame heats directly the end of the combustion

cylinder 73 to the first heat transfer fins 312 formed in the rear end of the combustion

chamber 33 by the fuel pumping pressure. And the combustion flame injected from the

combustion cylinder 73 strikes the diffusing plate 39 in the rear end of the combustion

chamber 33, and then diffuses in the combustion chamber 33 to heat the first heat transfer

fins 312 again. And the combustion flame and exhaust gas injected from the combustion

cylinder 73 is induced into the gaps 315 and swirl passes 316 formed between the first heat

transfer fins 312, and the induced combustion flame and exhaust gas go to the front end

cylindrical body 35 through the swirl induction holes 315 formed in the swirl passes 316.

Because the both protruding pieces 317, 318 incline in same direction, the combustion

flame and exhaust gas that pass through the swirl induction .holes 314 will go with rotation

by the both protruding pieces 317, 318. Thus, the time that the combustion flame and exhaust gas contacts with the first heat transfer fins 312 will be increase, which gives high

heat transfer efficiency.

The heated first heat transfer fins 312 heat the second heat transfer fins 313 which

are protruded inside of the water jacket 35 via the inner wall 31, and then the cooling water

in the water jacket 35 is heated. Each of the second heat transfer fins 313 which are

protruded inside of the water jacket 35 has "^" shape that the both ends are bent in

opposite direction, so the cooling water that passes through the water jacket 35, will

revolve around the inner wall 31, which improve the heat transfer efficiency. For example,

when the cooling water is induced into the water jacket 35 via the first tube 35a, the heat

exchanging between the inner wall 31 and the second heat exchange fins 313 is improved

until the cooling water is discharged via the second tube 35b, which enables quick heating

of the cooling water to the desired temperature.

And, the heated cooling water within the water jacket 35 transfer the heat to the

plural heat discharge member 341 that forms the outer wall 34 and plural heat discharge

fins 342 on the outer face of the outer wall. Thus, the plural heat discharge member 341

and plural heat discharge fins 342 can also heated quickly, and then transfer the heat to the

cold air that flows within the heat exchange pass 8 formed by the air duct 6. Because each

of the plural heat discharge fins 342 inclines by same degree, the cold air that flows within

the heat exchange pass 8 will revolve within the heat exchange pass 8, which increase heat

exchanging time between the outer wall 34 and plural heat discharge fins 342. Finally, the cold air induced by the induction tube 61 is heated during the air passes the heat exchange

pass 8, and discharged from the discharging tube 62.

For the embodiment in Fig. 12, the heat transfer fins 312a formed in the inner face

of the inner wall 31a of the water jacket, are heated by the combustion flame of the burner

7, the transferred heat is delivered to the cooling water in the water jacket 35, and then the

heat in the cooling water is delivered to the outer wall 34 and heat discharge fins 342a,

which enables heating the air that passes through the heat exchange pass 8. The heat

exchanging efficiency is lower than the embodiment in Fig. 5 because there is no swirling

of cooling water and air. But, the manufacturing cost can be reduced due to the simple

structure.

Now, the operation of the dual heating system will be described.

The dual heating system 1 is controlled automatically by the electronic controlling

unit which is controlled by the switches provided in the instrument panel of the vehicle,

and the detailed description for the electronic controlling unit and the switches.

For the embodiment in the Fig. 1 to 3, when it is desired only cabin heating

without staring the engine, the control unit opens the air damper 63 in the induction tube

61, ignites the burner 7, and running the water pump 5 for the air heater.

As described, the burner 7 heats the dual heater heat exchanger 3 rapidly, and the water pump 5 for the air heater circulates the cooling water. So, the cooling water is

induced into the water jacket 35 via the second tube 35b, heated in the water jacket by the

second heat transfer fins 313, and then return to the cooling water collecting line 13 via the

first tube 35a and the first by-pass line 2a. At this time, the cooling water doesn't flow

toward the engine 10 due to the flow resistance of the stopped engine 10, but flows toward

check valve 21. The cooling water that passed through the check valve 21 flows toward the

second by-pass line 2b by the pumping force of the water pump 5 for the air heater.

Thus, when the water pump 5 for the air heater runs with the engine 10 stopped,

the cooling water will flows as in the direction indicated by the arrow in the Fig. 1. That is,

the cooling water circulates repeatedly in following manners;

the water pump 5 → the second tube 35b → the water jacket 35 → the first

tube 35a → the first by-pass line 2a — ^» the check valve 21 → the second by-pass line

2b.

Such repeated circulation between the first and second by-pass line 2a, 2a will

maximize the heat transfer efficiency of the dual heater heat exchanger 3.

Thus, the cold air induced into the heat exchange pass 8 between the air duct 6

and heat exchanger 3 via the induction tube 61 is heated by contacting the outer wall of the

heat exchanger 3 and heat discharge fins 342. Because each of the plural heat discharge

fins 342 inclines by same degree, the cold air that flows within the heat exchange pass 8

will revolve within the heat exchange pass 8, which increase heat exchanging time between the outer wall 34 and plural heat discharge fins 342. Finally, the cold air induced by the

induction tube 61 is heated during the air passes the heat exchange pass 8, and discharged

from the discharging tube 62.

When it is required only engine warm-up with the engine 10 stopped, the control

unit runs the burner 7 and water pump 4 for free heater with the air damper close.

When the and water pump 4 for free heater runs, the cooling water in the cooling

water collecting line 13 flows in following order;

the second by-pass line 2a → the first tube 35a → the water jacket 35 → the

• second tube 35b → the second by-pass line → the cabin heater 11 — > the cooling water

supplying line → the engine 10 → the cooling water collecting line 13.

The cooling water that circulates within the water jacket 35 of the dual heater heat

exchanger 3 flows through the engine 10 with heated state, which enables the engine

warm-up.

When it is required both engine warm-up and cabin heating, the control unit opens

the air damper 63, ignites the burner 7, and running the water pump 4 for the free heater.

When the water pump 4 for the free heater runs, the cooling water flows the same

way as in the engine warm-up. That is;

the second by-pass line 2a → the first tube 35a -→ the water jacket 35 → the

second tube 35b → the second by-pass line → the cabin heater 11 -→ the cooling water

supplying line → the engine 10 → the cooling water collecting line 13. The cooling water that circulates within the water jacket 35 of the dual heater heat

warm-up. And the cold air induced via the induction tube 61 is heated during the air passes

the heat exchange pass 8, and discharged from the discharging tube 62.

For the embodiment in Fig. 4, it can heat the cabin or warm-up the engine

selectively, or heat and warm-up simultaneously by controlling the 3-way solenoid valve

5 a which control the flow of the cooling water, and the air damper 63 all of which are

controlled by the switches in the instrument panel. For example, when open the air damper

63 and control the 3-way solenoid valve 5a to flow the cooling water into the third by-pass

line 2c, the cooling water flows as following order;

the first by-pass line 2a → the first tube 35a → the water jacket 35 → the

second tube 35b → the second by-pass line 2b → the 3-way solenoid valve 5a → the

third by-pass line 2c.

Thus, the cooling water can be heated quickly to the desired temperature for the

cabin heating.

INDUSTRIAL UTILIZABILITY

According to the present invention, with the smaller amount of fuel than required

in running the engine, it is possible to heat the cabin and warm-up the engine. And it is also possible to warm-up the engine and heat the cabin heating selectively or simultaneously.

While the present invention has been particularly shown and described with

reference to the preferred embodiments thereof, it will be appreciated that many variations,

modifications, and other applications of the present invention may be made without

affecting the spirit and scope.

Claims

What is claimed is

1. a heat exchanger which comprises

a burner to which the fuel is supplied directly from the fuel tank;

a cylindrical inner wall that forms a combustion chamber and connected to the

end of the burner;

a cylindrical outer wall that is installed concentrically with the inner wall with

water of the engine passes;

an air duct that is installed with some distance from the outer face of the outer

wall, and one end of which is connected to the outside air and the other end of which is

connected to the air vent of the vehicle cabin;

an air damper installed in the air duct;

and a fan installed between the burner and the air damper.

2. The heat exchanger as in claim 1, wherein the inner wall is formed by

connecting plural ring-shaped heat transfer members longitudinally, and one end of the

inner wall is closed by the arch-shaped diffuser.

3. The heat exchanger as in claim 2, wherein the heat transfer member that forms the inner wall has a flange in inner face inner edge of which is curved in the direction of

the exhaust gas flow.

4. The heat exchanger as in claim 3, wherein plural swirl inducing holes are

formed on the perpendicular face of the flange through which the exhaust gas is discharged

in the tangential direction to the inner wall.

5. The heat exchanger as in claim 2, wherein plural heat transfer fins are formed

radially on the outer face of the heat transfer member.

6. The heat exchanger as in claim 1, wherein the outer wall is formed by

outer wall is closed by the sealing plate.

7. The heat exchanger as in claim 6, wherein plural heat transfer fins are formed

radially on the outer face of the heat transfer member for the outer wall.

8. a heating system for internal combustion engine which comprises an engine; a

cabin heater to heat the cabin of the vehicle using the cooling water for the engine; a

cooling water collecting line through which the cooling water flows from the engine to the cabin heater; a cooling water supply line through which the cooing water flows from the

cabin heater to the engine, wherein the heating system further comprises

the heat exchanger according to the one of the claim 1 to 7;

the first by-pass line connecting the cooling water collecting line and the first

opening;

the second by-pass line connecting the second opening and cooling water

collecting line;

water pumps for the free heater and air heater that are respectively installed on the

first by-pass line and the second by-pass line, and send the cooling water to the heat

exchanger; and

a check valve that is installed between the first by-pass line and the second by¬

pass line and blocks the flow form the second by-pass line to the first by-pass line.

9. a heating system for internal combustion engine which comprises an engine; a

cooling water collecting line through which the cooling water flows from the engine to the

cabin heater; a cooling water supply line through which the cooing water flows from the

cabin heater to the engine, wherein the heating system further comprises

the heat exchanger according to the one of the claim 1 to 7;

the first by-pass line connecting the coolmg water collecting line and the first opening;

the second by-pass line connecting the second opening and cooling water

collecting line;

the third by-pass line the connects the first by-pass line and the second by-pass

line;

a water pump that is installed on either of the first by-pass line and the second by¬

pass line, and send the cooling water to the heat exchanger;

a 3-way solenoid valve that is installed on the by-pass line on which the water

pump is not installed, and connected to the third by-pass line; and