JP3343665B2 - Exhaust gas heat exchanger - Google Patents

Abstract

PURPOSE:To reduce in size by obtaining a high heat exchanging efficiency, to improve an exhaust efficiency without decreasing engine performance, to improve a silencing effect and to integrate it with an engine. CONSTITUTION:An exhaust gas heat exchanger 4 heat exchanges exhaust gas flowing in an exhaust passage with other fluid flowing out of the passage, and comprises an upstream side heat exchanging unit 10 having an uneven part at an expansion chamber 12 of the passage, wherein the unit 10 is connected directly to an exhaust side of the engine.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust gas heat exchange device used for a gas heat pump device driven by a gas engine, for example.

[0002]

2. Description of the Related Art For example, in a gas heat pump device driven by a gas engine, high-temperature, high-pressure exhaust gas discharged from the gas engine is led to an exhaust gas heat exchange device, and the waste heat that escapes along with the exhaust gas is released. To exchange waste heat with cooling water to recover waste heat, reduce the pressure of exhaust gas by cooling to mute noise, or improve exhaust efficiency.

In the conventional exhaust gas heat exchange apparatus, the exhaust passage through which the exhaust gas flows is constituted by a thin pipe wound in a spiral shape, or a straight pipe having a turbulence generating plate attached to the inner wall. .

[0004]

However, when the exhaust passage of the exhaust gas heat exchange device is constituted by a thin pipe wound in a spiral shape, carbon contained in the exhaust gas adheres to the inner surface of the pipe. Pipes are easily clogged, the surface area per unit length of the pipe is reduced, and the heat exchange efficiency is deteriorated.

Also, when the exhaust passage is formed by a straight pipe having a turbulence generating plate attached to the inner wall, a problem that high heat exchange efficiency cannot be obtained because the surface area per unit length of the straight pipe is small. is there.

Further, when such an exhaust passage is constituted by a thin pipe wound spirally or a straight pipe having a turbulence generating plate attached to an inner wall thereof, the exhaust resistance is reduced by directly connecting the exhaust passage to a gas engine. There is a problem that the exhaust efficiency is large and the exhaust efficiency is low, and the exhaust pressure is large and the noise reduction effect is not sufficient. Further, there is a problem that the engine performance is deteriorated, and it has been difficult to directly assemble the gas engine directly.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and it is possible to obtain high heat exchange efficiency and reduce the size of the engine. It is an object of the present invention to provide an exhaust gas heat exchange device that can improve the effect and can be integrated with an engine.

[0008]

According to a first aspect of the present invention, heat exchange is performed between exhaust gas flowing in an exhaust passage and another fluid flowing outside the exhaust passage. in the exhaust gas heat exchanger, the exhaust of the exhaust passage
Fins are provided on the surface of the expansion chamber provided directly at the gas inlet.
The outer surface of the expansion chamber on the side of the cooling water passage while providing many projections
Is characterized by having a smooth shape .

The invention according to claim 2 is characterized in that the expansion chamber is provided.
A large number of fins and projections provided on the inner surface
And are arranged in a zigzag pattern .

[0010]

According to the first aspect of the present invention, the exhaust gas inlet is directly connected to the exhaust gas inlet.
Since the expansion chamber is provided, the exhaust gas exhaust resistance
The resistance is reduced and the exhaust efficiency is improved.
The force is reduced and the noise reduction effect is improved.
High heat exchange efficiency can be obtained due to the large area
You. Also, before the temperature is reduced by the exhaust passage, the expansion chamber is closed.
Since there are many fins and projections inside the installation, exhaust gas temperature
High degree of heat exchange and surface for heat exchange
A large product can be secured. On the other hand, expansion on the cooling water passage side
The outdoor surface has a smooth shape, and the outside of the expansion chamber has a smooth shape.
The cooling water passage,
-Accumulation is less likely to occur, preventing problems on the cooling unit side
Heat exchange on the cooling water side is better than heat exchange on the gas side.
Heat transfer is much better, so multiple
There is no need to apply rough shapes. Conversely, the cooling water passage side
The rough shape may cause air accumulation in the cooling water.
Become.

According to the second aspect of the present invention, the fin and the projection
The arrangement is staggered with respect to the exhaust gas flow
Thus, the heat exchange efficiency increases.

[0012]

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an exhaust gas heat exchanger according to the present invention will be described below with reference to the drawings. 1 is a side view of a gas engine to which an exhaust gas heat exchange device is assembled, FIG. 2 is a cross-sectional view of the exhaust gas heat exchange device, FIG. 3 is a side view of the exhaust gas heat exchange device, and FIG. 4 is IV-IV in FIG. 5 is a sectional view taken along line VV of FIG. 2, FIG. 6 is a sectional view taken along line VI-VI of FIG. 2, and FIG. 7 is a sectional view of a screw pipe.

The gas engine 1 is a drive source of a gas heat pump device. The gas engine 1 operates using gas as fuel. A compressor (not shown) is driven by the gas engine 1, and the compressor generates a refrigerant. It is compressed and provided for cooling or heating.

The gas engine 1 has a cylinder 2 arranged at an angle, and an exhaust gas heat exchange device 4 is mounted on the side of the exhaust side 3 of the engine 1. The gas engine 1 and the exhaust gas heat exchange device 4 are integrated. Has been To assemble the exhaust gas heat exchange device 4, a lower mounting portion 7a formed on a casing 7 of the exhaust gas heat exchange device 4 is fastened and fixed to a mounting stay 6 fixed to a lower portion of the gas engine 1 with bolts 5 with bolts 8, The upper mounting portion 7b formed on the casing 7 of the exhaust gas heat exchange device 4 is directly fastened and fixed to the gas engine 1 with mounting bolts 9.

The exhaust gas heat exchanging device 4 includes an upstream heat exchanging section 10 having projections and depressions in the expansion chamber of the exhaust passage, and a downstream heat exchanging section 11 having the exhaust passage formed by a screw pipe having a non-circular cross section. Have been.

In the upstream heat exchange section 10, an expansion chamber 12 of an exhaust passage is formed in a casing 7, and fins 13 and projections 14 form irregularities in the expansion chamber 12. In the expansion chamber 12, a partition wall 7d extends from one side 7c in proximity to the other side 7e, and an upper expansion chamber 12a and a lower expansion chamber 12b communicating with the side 7e are formed. .

An upper cooling water passage 15a is formed around the upper expansion chamber 12a of the exhaust passage of the upstream heat exchange section 10, and the upper cooling water passage 15a extends to the partition wall 7d.
A lower cooling water passage 15b is formed around the lower expansion chamber 12b. Cooling water is guided from the downstream heat exchange unit 11 to the lower cooling water passage 15b. The cooling water is discharged from a cooling water outlet 15c formed in the upper part of the casing 7 through the passage 15a, and the cooling water is supplied to the cooling water passage of the gas engine 1. Thus, cold
The outer surface of the expansion chamber on the side of the recirculating water passage has a smooth
The upper cooling water passage 15a has a smooth shape outside the room, and the lower cooling
The water passage 15b allows air to accumulate in the cooling water.
Disturbance is less likely to occur, and trouble on the cooling unit side can be prevented before it occurs.
In addition, heat exchange on the cooling water side is more heat than heat exchange on the gas side.
Transmission is much better, so complex
It is not necessary to apply a shape, and conversely, complicated
The shape may cause air accumulation in the cooling water.
You.

The upstream heat exchange section 10 has a connection 7 f formed in the casing 7, and this connection 7 f can be directly connected to the exhaust side 3 of the gas engine 1. Gas engine 1
Exhaust gas is introduced into the upper expansion chamber 12a from the exhaust gas inlet 16 formed at four places of the casing 7 from the exhaust side 3 of the casing 7, and this exhaust gas is guided to the lower expansion chamber 12b, and further, the downstream heat exchanger 11 It is led to.

As described above, the high-temperature, high-pressure exhaust gas generated by the combustion of the air-fuel mixture in the combustion chamber of the gas engine 1
Introduced into the upstream heat exchange section 10 of the exhaust gas heat exchanger 4,
Here, heat is exchanged with the cooling water to be cooled.

The expansion chamber 12 in the exhaust passage of the upstream heat exchange section 10 reduces the exhaust resistance of the exhaust gas from the exhaust side 3 of the gas engine 1, thereby improving the exhaust efficiency and reducing the exhaust pressure. The silencing effect is also improved. In addition, the fin 13 is provided in the expansion chamber 12 of the upstream heat exchange section 10.
The protrusions and projections 14 form irregularities, and the irregularities increase the surface area, so that high heat exchange efficiency can be obtained. The arrangement of the fins 13 and the projections 14 is
Since they are arranged in a zigzag pattern with respect to the flow, the heat exchange efficiency
Get higher.

The exhaust gas passage of the downstream heat exchange section 11 is constituted by a screw pipe 20 having a non-circular cross section.
1 is provided, a gasket 22 is provided on the other side, and a guide plate 23 is provided on an intermediate portion to form a pipe unit 24. As shown in FIG. 7, the screw pipe 20 has a cruciform cross section, and radially protrudes from its outer periphery.
The two projections 20a draw a spiral along the length direction on the outer circumference of the screw pipe 20.

The pipe unit 24 is disposed in a cooling water chamber 25 formed in the casing 7. A cooling water inlet 26 is formed below the cooling water chamber 25, and a cooling water outlet 27 is formed above the cooling water chamber 25.
Is formed. Cooling water is supplied from the gas engine 1 to a cooling water chamber 25 from a cooling water inlet 26, and the cooling water chamber 2
5 and is supplied from the cooling water outlet 27 to the lower cooling water passage 15b of the upstream heat exchange unit 10.

The closing plate 21 of the pipe unit 24 is sealed with an O-ring 28, and the cover 30 is further bolted to the side 7 e of the casing 7 via a gasket 29.
Is fixed. A collective exhaust chamber 32 is formed by the cover 30, an exhaust gas outlet 33 is provided at the center of the cover 30, and a drain water outlet 34 is provided below the cover 30.

The other of the pipe unit 24 is the gasket 2
2 is fastened to the side 7c of the casing 7 with the bolt 35,
Further, the cover 37 is connected to the bolt 37 via the gasket 22.
At the side 7c of the casing 7.
A communication collective exhaust chamber 38 is formed by the cover 36, and exhaust gas is introduced into the communication collective exhaust chamber 38 from the lower expansion chamber 12 b of the upstream heat exchange unit 10. The exhaust gas is led from the communicating collective exhaust chamber 38 to the collective exhaust chamber 32 through the screw pipe 20 of the pipe unit 24, and is discharged from the collective exhaust chamber 32 from the exhaust gas outlet 33.

As described above, since the exhaust passage of the downstream heat exchange section 11 is constituted by the screw pipe 20, the exhaust gas flows in the screw pipe 20 as a swirling flow.
The heat transfer rate of the exhaust gas to the cooling water is increased by the turbulence effect of the exhaust gas, and high heat exchange efficiency is obtained.

In the exhaust gas heat exchanger 4, the exhaust gas exchanges heat with the cooling water in the upstream heat exchange section 10 and the downstream heat exchange section 11 to effectively recover the heat of the exhaust gas. At the same time, the temperature and pressure are reduced, and exhaust noise is reduced. Exhaust gas that has completed heat exchange with the cooling water is introduced into an exhaust silencer (not shown), where it is silenced, and finally released into the atmosphere.

[0028]

As is apparent from the above description, the invention according to claim 1 has a structure in which an expansion chamber is provided immediately at the exhaust gas inlet.
The exhaust resistance of the exhaust gas is reduced
Improves efficiency and reduces exhaust pressure to reduce noise
The effect is improved and the surface area of the expansion chamber is increased.
Therefore, high heat exchange efficiency can be obtained. Also, the exhaust passage
Before the temperature drops, provide an expansion chamber and a large number of fins inside.
And projections, so that heat
And a large surface area for heat exchange can be secured. one
On the other hand, the outer surface of the expansion chamber on the side of the cooling water passage has a smooth shape.
The outside of the expansion chamber becomes a smooth shape and becomes a passage for cooling water.
Air is hardly generated in the cooling water.
To prevent troubles on the cooling unit side,
Water side heat exchange is much better than gas side heat exchange
So it is not necessary to apply complicated shapes to secure the surface area
Absent.

Further, the invention according to claim 2 is characterized in that
The stirrer is arranged in a zigzag pattern with respect to the exhaust gas flow.
Therefore, the heat exchange efficiency increases.

[0030]

[0031]

[Brief description of the drawings]

FIG. 1 is a side view of a gas engine to which an exhaust gas heat exchange device is assembled.

FIG. 2 is a sectional view of an exhaust gas heat exchange device.

FIG. 3 is a side view of the exhaust gas heat exchange device.

FIG. 4 is a sectional view taken along the line IV-IV in FIG. 2;

FIG. 5 is a sectional view taken along line VV in FIG. 2;

FIG. 6 is a sectional view taken along the line VI-VI of FIG. 2;

FIG. 7 is a sectional view of a screw pipe.

[Explanation of symbols]

 4 Exhaust Gas Heat Exchanger 10 Upstream Heat Exchanger 11 Downstream Heat Exchanger 12 Expansion Chamber 20 Screw Pipe

Continuation of the front page (56) References JP-A-1-193014 (JP, A) JP-A-5-39990 (JP, A) JP-A-5-137944 (JP, A) Jpn. , U) Shokai Sho 62-67916 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F28D 7/10 F01N 5/02 F25B 27/02 F28F 1/02 F28F 1/40

Claims (2)

(57) [Claims] 1. An exhaust gas heat exchange device for exchanging heat between exhaust gas flowing in an exhaust passage and another fluid flowing outside the exhaust passage, wherein the heat exchanger is provided directly at an exhaust gas inlet of the exhaust passage . Expansion chamber
A large number of fins and projections are provided on the inner surface, while the cooling water passage
An exhaust gas heat exchange device characterized in that the outer surface of the expansion chamber on the side has a smooth shape . And a plurality of fins provided on the inner surface of the expansion chamber.
To stagger the exhaust gas flow.
The exhaust gas heat exchange device according to claim 1, wherein: