KR20180009622A - Heat exchanger - Google Patents

Abstract

The present invention relates to a heat exchanger capable of regulating a rise in a back pressure of exhaust gas and also minimizing heat loss. The heat exchanger according to the present invention includes: a housing having a chamber in which a first fluid and a second fluid exchange heat between each other; a heat cover surrounding the housing; a bypass passage formed between an inner surface of the heat cover and an outer surface of the housing; a bypass conduit extending from an upstream of the housing to the bypass passage; and a bypass valve provided in the bypass conduit so as to be openable and closable.

Description

Heat Exchanger {HEAT EXCHANGER}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger, and more particularly, to a heat exchanger capable of minimizing heat loss while regulating the back pressure of exhaust gas.

A heat exchanger is a device for transferring heat between two or more fluids. In a broad sense, it includes a heater, a cooler, a condenser, and the like, but for the purpose of recovering heat, it is called a heat exchanger. Such a heat exchanger can be applied to various industrial fields such as a vehicle, a boiler, a ship, a facility, and the like.

Meanwhile, various heat exchangers such as a condenser, a boiler, and the like are applied to the Rankine cycle of a waste heat recovery system of a vehicle. The waste heat recovery system of such a vehicle is provided with a heat exchanger such as an exhaust gas boiler or an EGR gas boiler that uses exhaust gas or EGR gas as a heat source to heat the working fluid of the Rankine cycle.

The EGR gas boiler is mounted on the side of the engine located at the bottom of the body of the vehicle or the cab of the commercial vehicle, so there is little heat loss due to the surrounding environment.

The exhaust gas boiler is mounted on the downstream side of the catalytic converter, the muffler, and the like on the structure of the exhaust system. Since the exhaust gas boiler is disposed close to the ground and exposed to the outside, More heat loss may occur during winter or rainy weather.

Accordingly, the exhaust gas boiler of the waste heat recovery system of the vehicle is required to be heat-treated to prevent heat loss.

In addition, the back pressure of the exhaust gas may increase due to the exhaust resistance of the exhaust gas boiler, and particularly, when the back pressure of the exhaust gas rises above a certain level, the fuel consumption may be adversely affected. In order to cope with the back pressure rise of the exhaust gas, it is possible to secure and improve the flow path of the exhaust gas by increasing the sectional area of the heat exchanger. However, when the sectional area of the heat exchanger is increased, the size of the heat exchanger excessively increases excessively Weight and cost may be increased.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a heat exchanger capable of minimizing heat loss while regulating the back pressure rise of exhaust gas or EGR gas

According to an aspect of the present invention, there is provided a heat exchanger comprising:

A housing having a chamber in which a first fluid and a second fluid exchange heat;

A heat cover surrounding the housing;

A bypass passage formed between an inner surface of the heat cover and an outer surface of the housing;

A bypass conduit extending from the upstream of the housing to the bypass passage; And

And a bypass valve provided in the bypass conduit to be openable and closable.

As the bypass valve is closed, the first fluid can exchange heat with the second fluid while passing through the chamber of the housing, and as the bypass valve is opened, at least a portion of the first fluid passes through the bypass passage And can exchange heat with the second fluid.

A bypass valve is rotatably installed in the bypass conduit, and the flow path of the bypass conduit can be opened and closed by the rotation of the bypass valve.

And an elastic member for applying an elastic force to rotate the bypass valve in the closing direction.

Wherein the elastic member is an extension spring, a first support portion is formed on one surface of the bypass valve, a second support portion is formed on an inner surface of the bypass conduit adjacent to the bypass valve, Can be individually supported by the first support portion and the second support portion.

A guide for guiding the flow of the first fluid in a predetermined direction may be formed on the inner surface of the heat cover.

An inlet cap through which the first fluid flows may be provided at one end of the housing, and an outlet cap through which the first fluid may be discharged may be provided at the other end of the housing.

The outer surface of the housing is provided with an inlet port through which the second fluid flows and an outlet port through which the second fluid is discharged, and the inlet port and the outlet port may be diagonally spaced from the outer surface of the housing.

One end of the heat cover is provided with a closed end, and the other end of the heat cover is provided with an open end.

A first closed end is provided at one end of the heat cover, and a second closed end is provided at the other end of the heat cover.

According to the present invention, when exhaust gas or an EGR gas boiler or the like of a waste heat recovery system passes through exhaust gas or a heat exchanger through which the EGR gas passes, the exhaust gas or the EGR gas undergoes heat exchange It is possible to prevent the back pressure of the exhaust gas from being appropriately regulated so as to prevent the fuel economy from being adversely affected.

Particularly, the present invention is characterized in that a cover surrounding a housing of a heat exchanger through which exhaust gas or EGR gas passes is provided, and a bypass passage through which exhaust gas or EGR gas passes is formed between the housing and the cover, Can be minimized.

1 is a diagram illustrating a heat exchanger according to various embodiments of the present invention.
Fig. 2 is an enlarged view of a portion indicated by an arrow A in Fig. 1, showing a state in which the bypass valve is closed.
3 is a view showing a state in which the bypass valve is opened.
4 is a partially cut-away sectional view showing a state where a bypass valve of a heat exchanger according to the present invention is installed in a mounting space of a bipod conduit.
5 is a view showing a structure in which a guide is formed inside a heat cover of a heat exchanger according to the present invention.
6 is a view showing an embodiment in which the heat exchanger according to the present invention is disposed on the downstream side of the post-treatment apparatus of the exhaust system.
7 is a view showing an embodiment in which the heat exchanger according to the present invention is disposed on the upstream side of the post-treatment apparatus of the exhaust system.
8 is a view illustrating a heat exchanger according to another embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. For the sake of convenience, the size, line thickness, and the like of the components shown in the drawings referenced in the description of the present invention may be exaggerated somewhat. The terms used in the description of the present invention are defined in consideration of the functions of the present invention, and thus may be changed depending on the user, the intention of the operator, customs, and the like. Therefore, the definition of this term should be based on the contents of this specification as a whole.

Referring to Figure 1, a heat exchanger 10 according to various embodiments of the present invention includes a housing 11 having a chamber 13 in which a first fluid and a second fluid exchange heat, And may include a heat cover 20.

The housing 11 may be formed in a cylindrical shape or a rectangular parallelepiped shape. In the housing 11, a chamber 13 may be formed in which the first fluid and the second fluid flow separately while passing therethrough.

A plurality of tubes 12 are provided at a predetermined interval in the chamber 13 of the housing 11 and each tube 12 can extend along the longitudinal direction of the housing 11. [ The plurality of tubes 12 may be supported by one or more baffles 14, and the baffle 14 may have a plurality of through holes.

One end of the housing 11 is provided with an inlet cap 15 through which the first fluid flows, and one end of the housing 11 can be an upstream end. An outlet cap 16 for discharging the first fluid is provided at the other end of the housing 11, and the other end of the housing 11 may be a downstream end. The first fluid introduced through the inlet cap 15 may be discharged to the outlet cap 16 after passing through the plurality of tubes 12. [

An inlet port 17 through which the second fluid flows and an outlet port through which the second fluid is discharged may be provided in a periphery of the housing 11. [ The inlet port 17 and the outlet port 18 are located opposite to each other on the outer surface of the housing 11 and the inlet port 17 and the outlet port 18 are arranged so as to be spaced apart from each other in the longitudinal direction of the housing 11, The port 17 and the outlet port 18 may be disposed diagonally away from each other. The second fluid can then be discharged through the outlet port 18 after passing through the chamber 13 of the housing 11 and the second fluid introduced into the inlet port 17.

According to one embodiment, the heat exchanger 10 of the present invention may be an exhaust gas boiler or an EGR gas boiler installed in a Rankine cycle of a waste heat recovery system.

As illustrated in FIG. 6, the heat exchanger 10 may be an exhaust gas boiler disposed downstream of a post-treatment device 5, such as a purifier or muffler of an exhaust system, The machine 10 can be installed in the exhaust pipes 31 and 32 of the exhaust system. For example, the upstream side exhaust pipe 31 may be connected to the inlet cap 15 of the housing 11, and the downstream side exhaust pipe 32 may be connected to the outlet cap 16 of the housing 11.

As described above, when the heat exchanger 10 of the present invention is an exhaust gas boiler or an EGR gas boiler of a waste heat recovery system, the first fluid may be an exhaust gas or an EGR gas, and the second fluid may be a working fluid of a Rankine cycle, , Refrigerant, and the like, and in particular, the second fluid can be heated and evaporated by waste heat of exhaust gas or EGR gas.

The heat cover 20 may extend in the longitudinal direction of the housing 11 to surround the outer surface of the housing 11. A closed end 21 may be formed at one end of the heat cover 20 and a closed end 21 may be formed to be in close contact with the outer surface of the inlet cap 15.

An open end 22 may be formed at the other end of the heat cover 20 and an open end 22 may be radially spaced apart from the outer surface of the outlet cap 16, A passage through which the first fluid is discharged may be formed between the outer surfaces of the first and second openings 16. For example, when the heat exchanger 10 is disposed on the downstream side of the post-treatment apparatus 5 as in the embodiment of FIG. 6, the exhaust gas as the first fluid is appropriately purified by the post-treatment apparatus 5, 1 fluid can be discharged to the outside through the open end (22).

The bypass passage 25 can be formed by separating the inner surface of the heat cover 20 and the outer surface of the housing 11 at a predetermined interval. With this arrangement, the first fluid can be discharged through the open end 22 after passing through the bypass passage 25. [

A bypass conduit 23 is connected between the upstream exhaust pipe 31 connected to the upstream end (inlet cap 15) of the housing 11 and the heat cover 20 and the bypass conduit 23 is connected through the bypass conduit 23 At least a portion of the fluid may be introduced into the bypass passage 25. [

The bypass conduit 23 may have an inclined portion 23a inclined at an angle to the upstream exhaust pipe 31 and a horizontal portion 23b horizontally connected to the inclined portion 23a.

The closing end 21 of the heat cover 20 is provided with a coupling boss 24 and the end of the horizontal portion 23b of the bypass conduit 23 can be sealingly engaged with the coupling boss 24. [

The bypass conduit 23 may be provided with a bypass valve 35 to be openable and closable. The bypass valve 35 may have a disk shape such as a butterfly valve and the pivot shaft 36 may be provided at one side of the bypass valve 35. The bypass valve 35 is rotatably installed in the bypass conduit 23 by the pivot shaft 36 so that the flow path of the bypass conduit 23 can be opened and closed.

According to one embodiment, the pivot shaft 36 may be installed to be biased from the center line of the bypass valve 35 toward one direction. As a result, the opening operation of the bypass valve 35 due to the rise of the back pressure of the first fluid can be made more stable.

Between the bypass valve 35 and the bypass conduit 23, an elastic member 37 may be provided to apply an elastic force to rotate the bypass valve 35 in the closing direction.

According to one embodiment, the elastic member 37 may be an extension spring, a first support portion 38a is formed on one side of the bypass valve 35, and an inner surface of the bypass conduit 23 The second support portion 38b is formed and both ends of the elastic member 37 can be individually supported by the first support portion 38a and the second support portion 38b.

Accordingly, if the back pressure of the first fluid does not rise above the set value (corresponding to the threshold value of the back pressure that may adversely affect fuel efficiency), the elastic member 37 pulls the bypass valve 35 in the closing direction, (35) can be held in the closed position. When the back pressure of the first fluid rises above the set value, the elastic member 37 is pulled by the back pressure of the first fluid and the bypass valve 35 can be rotated to the open position.

On the other hand, the elastic member 37 is preferably configured to have an elastic force (elastic modulus) corresponding to a set value for the back pressure of the first fluid as a reference for opening and closing of the bypass valve 35.

On the inner surface of the bypass conduit 23, a valve seat 26, 27 with which the bypass valve 35 contacts can be formed.

5, the valve seats 26 and 27 include a first valve seat 26 in contact with one surface of the bypass valve 35 and a second valve seat 26 in contact with the other surface of the bypass valve 35 27). The first valve seat 26 and the second valve seat 27 may be staggered at intervals corresponding to the thickness t of the bypass valve 35.

The bypass conduit 23 may have an extension 28 formed on the downstream side of the valve seats 26 and 27 and the extension 28 may have an inclined portion 23a of the bypass conduit 23, (23b) can be connected. The width of the extended portion 28 may be larger than the width between the first valve seat 26 and the second valve seat 27. Particularly, at one side of the expansion part 28, the curved part 28a is formed to be convex downward so that the expansion part 28 has a width wider than the width of the first valve seat 26 and the second valve seat 27 Lt; / RTI >

When the bypass valve 35 is opened by the curved surface portion 28a of the enlarged portion 28, as shown in Fig. 3, between one side of the bypass valve 35 and the curved surface portion 28a of the expanded portion 28 An open passage 28b through which the first fluid can pass can be ensured so that the first fluid can flow stably to the bypass passage 25 through the bypass conduit 23. [

As described above, according to the present invention, when the bypass valve 35 is closed, the bypass valve 35 can be in tight airtight contact with the first valve seat 26 and the second valve seat 27, It is possible to prevent leakage to the bypass passage 25 through the path conduit 23 and to stably secure the open passage 28b by the expansion portion 28 when the bypass valve 35 is opened, A part of the fluid can flow stably to the bypass passage 25 through the bypass conduit 23.

According to various embodiments of the present invention, the curved portion 28a of the extension 28 may be located in the downward direction of the bypass conduit 23 and the pivot axis 36 may be located at the center of the bypass valve 35 That is, toward the first valve seat 26 at a predetermined interval S, as shown in Fig. The first support portion 38a may be formed on one surface of the bypass valve 35 adjacent to the first valve seat 26 and the second support portion 38b may be formed on one surface of the bypass valve 35 adjacent to the bypass valve 35 adjacent to the first valve seat 26, And may be disposed on the inner surface of the conduit 23. With this configuration, when the back pressure of the first fluid rises above the set value, the bypass valve 35, which is in contact with the first fluid, is easily rotated based on the deflected pivot shaft 36, There is an advantage that the opening operation can be performed more smoothly.

The operation of the bypass valve 35 will now be described with reference to FIGS. 3 and 4. FIG.

3, when the back pressure of the first fluid does not rise above the set value, the back pressure of the first fluid is smaller than the elastic force of the elastic member 37, so that the bypass valve 35 is biased by the elastic force of the elastic member 37, Can contact the valve seats 26, 27 and maintain the closed state of the flow path of the bypass conduit 23. The first fluid then flows through the inlet cap 15 of the housing 11 and can be discharged to the outlet cap 16 of the housing 11 after passing through the plurality of tubes 12. The second fluid then flows into the chamber 13 through the inlet port 17 to heat exchange with the first fluid passing through the plurality of tubes 12 and then through the outlet port 18 .

4, when the back pressure of the first fluid rises above the set value, the back pressure of the first fluid is greater than the elastic force of the elastic member 37, so that the elastic member 37 can be pulled, The bypass valve 35 is rotated by the back pressure, so that the flow path of the bypass conduit 23 can be opened. As the bypass valve 35 opens the flow path of the bypass conduit 23, at least a portion of the first fluid passes through the bypass passage 25 and undergoes heat exchange with the second fluid, And the remainder of the first fluid may pass through the plurality of tubes 12 through the inlet cap 15 and be heat exchanged with the second fluid before being discharged to the outlet cap 16 of the housing 11 Can be discharged.

As the back pressure of the first fluid rises above the set value, at least a part of the first fluid flows to the bypass passage 25, whereby the rise of the back pressure of the first fluid can be appropriately regulated, In the case of gas, fuel efficiency can be greatly improved.

In addition, since the first fluid having a relatively high temperature passes through the outer surface of the housing 11 and passes therethrough, the heat loss of the housing 11 can be blocked. In particular, the first fluid passing through the bypass passage 25 As the heat exchange with the second fluid is performed, the heating and evaporating efficiency of the second fluid can be further increased. In addition, the heat recovery efficiency can be improved and the heat exchange efficiency of the first fluid and the second fluid can be greatly improved.

A guide 45 for guiding the flow of the first fluid in a predetermined direction may be formed on the inner surface of the heat cover 20.

On the other hand, as the second fluid such as working fluid, refrigerant, cooling water and the like of the Rankine cycle flows into the inlet port 17 in the liquid state, the second fluid in the liquid state can be accumulated in the lower part of the chamber 13 of the housing 11 , And the interior of the chamber 13 may also have a non-uniform temperature distribution in which the temperature increases diagonally from the inlet port 17 to the outlet port 18. [ Thus, heating and evaporation of the second fluid by the first fluid may not be performed smoothly.

In order to cope with this, the guide 45 may be formed in an oblique direction on the inner surface of the heat cover 20.

In particular, as the inlet port 17 and the outlet port 18 of the housing 11 are diagonally spaced, the guide 45 may be formed in a diagonal direction that intersects the diagonal flow F2 of the second fluid . By crossing the flow direction F1 of the first fluid and the flow direction F2 of the second fluid passing through the bypass passage 25 between the heat cover 20 and the housing 11, The heat exchange efficiency of the two fluids can be greatly improved.

The heat exchanger 10 according to another embodiment may be a boiler disposed upstream of an after treatment device 5, such as a purifier or muffler of an exhaust system, as illustrated in FIG.

8, the first closed end 21 is formed at one end of the heat cover 20, and the first closed end 21 is formed at the other end of the heat cover 20, The second cover 23 is formed at the other end of the heat cover 20 so that the heat cover 20 can be sealed. One end of the recovery pipe 24 may be connected to the second closed end 23 of the heat cover 20 and the other end of the recovery pipe 24 may be connected to the downstream exhaust pipe 32. With this configuration, a part of the first fluid that has passed through the bypass passage 25 can be recovered to the exhaust pipe 32 on the downstream side via the recovery pipe 24.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. .

10: heat exchanger 11: housing
12: tube 13: chamber
20: heat cover 23: bypass conduit
25: bypass passage 35: bypass valve
36: pivot shaft 37: elastic member
45: Guide

Claims (10)

A housing having a chamber in which a first fluid and a second fluid exchange heat;
A heat cover surrounding the housing;
A bypass passage formed between an inner surface of the heat cover and an outer surface of the housing;
A bypass conduit extending from the upstream of the housing to the bypass passage; And
And a bypass valve provided in the bypass conduit to be openable and closable. The method according to claim 1,
As the bypass valve is closed, the first fluid undergoes heat exchange with the second fluid while passing through the chamber of the housing,
Wherein at least a portion of the first fluid passes through the bypass passage and heat-exchanges with the second fluid as the bypass valve is opened. The method according to claim 1,
Wherein a bypass valve is rotatably installed in the bypass conduit, and the flow path of the bypass conduit is opened and closed by rotation of the bypass valve. The method according to claim 1,
And an elastic member for applying an elastic force to rotate the bypass valve in the closing direction. The method of claim 4,
Wherein the elastic member is an extension spring, a first support portion is formed on one surface of the bypass valve, a second support portion is formed on an inner surface of the bypass conduit adjacent to the bypass valve, Is individually supported by the first support portion and the second support portion. The method according to claim 1,
And a guide for guiding the flow of the first fluid in a predetermined direction is formed on the inner surface of the heat cover. The method according to claim 1,
Wherein an inlet cap through which the first fluid flows is provided at one end of the housing, and an outlet cap through which the first fluid is discharged is provided at the other end of the housing. The method according to claim 1,
Wherein the housing has an inlet port through which the second fluid flows and an outlet port through which the second fluid is discharged, the inlet port and the outlet port being diagonally spaced from the outer surface of the housing. The method of claim 2,
Wherein the heat cover has a closed end at one end and an open end at the other end of the heat cover. The method of claim 2,
Wherein a first closed end is provided at one end of the heat cover and a second closed end is provided at the other end of the heat cover.

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