JPH0791775A - 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 in 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 and high-pressure exhaust gas discharged from the gas engine is guided to an exhaust gas heat exchange device, and waste heat that passes through together with this exhaust gas and escapes. The waste heat is recovered by exchanging heat with the cooling water, the pressure of the exhaust gas is lowered by cooling to muffle the sound, or the exhaust efficiency is improved.

By the way, in the conventional exhaust gas heat exchange device, the exhaust passage through which the exhaust gas flows is composed of a thin pipe spirally wound, or a straight pipe having a turbulent flow generation plate attached to its inner wall. .

[0004]

However, when the exhaust passage of the exhaust gas heat exchange device is constituted by a thin pipe spirally wound, carbon contained in the exhaust gas adheres to the inner surface of the pipe. Therefore, there is a problem that the pipe is easily clogged and the surface area per unit length of the pipe becomes small, resulting in poor heat exchange efficiency.

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

Further, if such an exhaust passage is constituted by a thin pipe wound in a spiral shape or a straight pipe having a turbulent flow generation plate attached to its inner wall, the exhaust resistance is increased when directly connected to a gas engine. It is large and the exhaust efficiency is low, and the exhaust pressure is large and the sound deadening effect is not sufficient. Further, there is a problem that the engine performance is deteriorated, and it is difficult to assemble the gas engine directly.

The present invention has been made in view of the above-mentioned problems, and it is possible to obtain a high heat exchange efficiency and to reduce the size, and further, to improve the exhaust efficiency without reducing the engine performance and to reduce the noise. It is an object of the present invention to provide an exhaust gas heat exchange device which can improve the effect and can be integrated with an engine.

[0008]

In order to solve the above-mentioned problems, the invention as claimed in claim 1 is an exhaust system for exchanging heat between an exhaust gas flowing in an exhaust passage and another fluid flowing outside the exhaust passage. The gas heat exchange device is characterized in that the expansion chamber of the exhaust passage has an upstream heat exchange section having irregularities, and the upstream heat exchange section can be directly connected to the exhaust side of the engine.

Further, in the exhaust gas heat exchange device for exchanging heat between the exhaust gas flowing inside the exhaust passage and another fluid flowing outside the exhaust passage, the expansion chamber of the exhaust passage is provided. It has an upstream heat exchange part having unevenness and a downstream heat exchange part where the exhaust passage is composed of a screw pipe with a non-circular cross section, and the upstream heat exchange part can be directly connected to the exhaust side of the engine. It is characterized by having done.

[0010]

According to the first aspect of the invention, the heat exchanger has an upstream heat exchange portion, and the upstream heat exchange portion can be directly connected to the exhaust side of the engine. Exhaust gas is exhausted from the exhaust side of the engine into the expansion chamber of the exhaust passage of the upstream heat exchange section, and this expansion chamber reduces exhaust resistance of the exhaust gas to improve exhaust efficiency and also reduces exhaust pressure. The sound deadening effect is also improved. Moreover, since the surface of the expansion chamber is increased due to the unevenness of the expansion chamber, the heat transfer coefficient of the exhaust gas to other fluids is increased, and high heat exchange efficiency can be obtained.

According to the second aspect of the present invention, the heat exchanger comprises an upstream heat exchange section and a downstream heat exchange section, and the upstream heat exchange section can be directly connected to the exhaust side of the engine. Exhaust gas is exhausted from the exhaust side of the engine into the expansion chamber of the exhaust passage of the upstream heat exchange section, and this expansion chamber reduces exhaust resistance of the exhaust gas to improve exhaust efficiency and also reduces exhaust pressure. The sound deadening effect is also improved. Moreover, since the surface of the expansion chamber is increased due to the unevenness of the expansion chamber, the heat transfer coefficient of the exhaust gas to other fluids is increased, and high heat exchange efficiency can be obtained.

Exhaust gas is introduced from the upstream side heat exchange section to the downstream side heat exchange section. However, since the exhaust gas passage is constituted by a screw pipe in this downstream side heat exchange section, the exhaust gas flows inside the screw pipe. The flow becomes a swirl flow, and the turbulent effect of the exhaust gas enhances the heat transfer coefficient of the exhaust gas to other fluids, resulting in high heat exchange efficiency.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of an exhaust gas heat exchange device of the present invention will be described below with reference to the drawings. 1 is a side view of a gas engine having an exhaust gas heat exchange device assembled therein, 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 of 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 by using gas as a fuel. The gas engine 1 drives a compressor (not shown), and the compressor generates a refrigerant. Compressed and used for cooling or heating.

The cylinder 2 of the gas engine 1 is arranged so as to be inclined, and an exhaust gas heat exchange device 4 is attached to the side of the exhaust side 3 of the engine 1 so that the gas engine 1 and the exhaust gas heat exchange device 4 are integrated. Has been converted. The exhaust gas heat exchange device 4 is assembled by fastening the lower mounting portion 7a formed on the casing 7 of the exhaust gas heat exchange device 4 to the mounting stay 6 fixed to the lower portion of the gas engine 1 with the bolt 5, and fixing it. 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 a mounting bolt 9.

The exhaust gas heat exchange device 4 is provided with an upstream heat exchange section 10 having an unevenness in the expansion chamber of the exhaust passage, and a downstream heat exchange section 11 having an exhaust passage formed of a screw pipe having a non-circular cross section. Has been.

In the upstream heat exchange section 10, an expansion chamber 12 of an exhaust passage is formed in a casing 7, and in this expansion chamber 12, fins 13 and projections 14 are formed to be uneven. In the expansion chamber 12, a partition wall 7d extends from one side portion 7c in proximity to the other side portion 7e, and an upper expansion chamber 12a and a lower expansion chamber 12b that are in communication on the side portion 7e side 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.
Further, a lower cooling water passage 15b is formed around the lower expansion chamber 12b, cooling water is guided from the downstream heat exchange section 11 to the lower cooling water passage 15b, and the upper cooling water is supplied from the lower cooling water passage 15b. The cooling water is discharged from a cooling water outlet 15c formed in the upper portion of the casing 7 through the passage 15a, and the cooling water is supplied to the cooling water passage of the gas engine 1.

A connecting portion 7f is formed in the casing 7 of the upstream heat exchange portion 10, and the connecting portion 7f can be directly connected to the exhaust side 3 of the gas engine 1. Gas engine 1
Exhaust gas from the exhaust side 3 is introduced into the upper expansion chamber 12a through exhaust gas inlets 16 formed at four locations of the casing 7, and this exhaust gas is guided to the lower expansion chamber 12b, and further downstream heat exchange section 11 Be 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 is
Introduced into the upstream heat exchange section 10 of the exhaust gas heat exchanger 4,
Here, it is cooled by exchanging heat with the cooling water.

Due to the expansion chamber 12 in the exhaust passage of the upstream heat exchange section 10, the exhaust resistance of the exhaust gas from the exhaust side 3 of the gas engine 1 is reduced, the exhaust efficiency is improved, and the exhaust pressure is reduced. The sound deadening effect is also improved. Moreover, the fins 13 are provided in the expansion chamber 12 of the upstream heat exchange section 10.
The protrusions and protrusions 14 form irregularities, and the irregularities increase the surface area, so that high heat exchange efficiency can be obtained.

The exhaust gas passage of the downstream heat exchange section 11 is constituted by a screw pipe 20 having a non-circular cross section, and the closing plate 2 is provided at one end of the plurality of screw pipes 20.
1 is provided, a gasket 22 is provided on the other side, and a guide plate 23 is provided at an intermediate portion to form a pipe unit 24. As shown in FIG. 7, the screw pipe 20 has a cruciform cross section, and projects radially toward the outer periphery thereof.
The two convex portions 20a draw a spiral along the lengthwise direction on the outer circumference of the screw pipe 20.

The pipe unit 24 is arranged 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.
Are formed. Cooling water is supplied from the gas engine 1 to the cooling water chamber 25 through the 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 section 10.

The closing plate 21 of the pipe unit 24 is sealed with an O-ring 28, and the cover 30 is further bolted via a gasket 29 to the side portion 7e of the casing 7.
It is fastened and fixed to. 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 under the cover 30.

The other side of the pipe unit 24 is the gasket 2.
2 is fastened to the side portion 7c of the casing 7 with the bolt 35,
Further, the cover 36 is fixed to the bolt 37 via the gasket 22.
It is fastened and fixed to the side portion 7c of the casing 7.
The cover 36 forms a communicating and collecting exhaust chamber 38, and exhaust gas is introduced into the communicating and collecting exhaust chamber 38 from the lower expansion chamber portion 12b of the upstream heat exchange section 10. The exhaust gas is guided 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 exhausted 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 as a swirling flow in the screw pipe 20,
Due to the turbulent effect of the exhaust gas, the heat transfer coefficient of the exhaust gas to the cooling water is increased, 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, and the heat contained therein is effectively recovered. At the same time, the temperature and pressure are lowered and exhaust noise is reduced. The exhaust gas that has completed heat exchange with this 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 the upstream heat exchange section, and the upstream heat exchange section can be directly connected to the exhaust side of the engine. The exhaust gas from the exhaust gas is reduced by the expansion chamber in the exhaust passage of the upstream heat exchange section to reduce exhaust resistance and improve exhaust efficiency, and also the exhaust pressure is reduced to improve noise reduction effect.
Moreover, the surface area increases due to the unevenness of the expansion chamber, and high heat exchange efficiency can be obtained. Therefore, it is possible to obtain high heat exchange efficiency, downsizing, and to improve exhaust efficiency without reducing engine performance, improve noise reduction effect, and integrate with the engine. is there.

Further, the invention according to claim 2 has an upstream heat exchange portion and a downstream heat exchange portion, and the upstream heat exchange portion can be directly connected to the exhaust side of the engine. The exhaust gas from the upstream heat exchange section has an expansion chamber in the exhaust passage that reduces exhaust resistance to improve exhaust efficiency, and also reduces exhaust pressure to improve the sound deadening effect. Can be increased to obtain high heat exchange efficiency.

Further, since the exhaust passage of the downstream heat exchange section is constituted by the screw pipe, the exhaust gas flows as a swirling flow in the screw pipe, and the turbulent effect of the exhaust gas causes other fluids of the exhaust gas to flow. The heat transfer rate to the
High heat exchange efficiency can be obtained, and high heat exchange efficiency can be obtained while suppressing the flow resistance of exhaust gas to a low level.

Therefore, a high heat exchange efficiency can be obtained, downsizing can be achieved, and the exhaust efficiency can be improved and the silencing effect can be improved without deteriorating the engine performance. Is possible.

[Brief description of drawings]

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

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

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

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

5 is a cross-sectional view taken along the line VV of FIG.

6 is a sectional view taken along line VI-VI in FIG.

FIG. 7 is a cross-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

Claims (2)

[Claims] 1. An exhaust gas heat exchange device for exchanging heat between an exhaust gas flowing in an exhaust passage and another fluid flowing outside the exhaust passage, wherein an upstream heat exchange having an unevenness in an expansion chamber of the exhaust passage. An exhaust gas heat exchange device, characterized in that the upstream side heat exchange section can be directly connected to the exhaust side of the engine. 2. 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 an upstream heat exchange having an unevenness in an expansion chamber of the exhaust passage. And a downstream side heat exchange section in which the exhaust passage is constituted by a screw pipe having a non-circular cross section, and the upstream side heat exchange section can be directly connected to the exhaust side of the engine. Gas heat exchanger.