JPH039397B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an exhaust gas heat exchanger used in a combustion device such as an engine.

Conventional configurations and their problems Conventionally, in exhaust gas heat exchangers used in combustion devices such as engines, those with a configuration that also enhances the silencing effect have an exhaust gas passage 2 inside a water chamber 1, as shown in Fig. 1. The heat quantity of the exhaust gas is recovered by passing the exhaust gas through the exhaust gas passage 2. However, in this format, the exhaust gas is
Since the exhaust gas passes through the center without colliding with the inner wall of the exhaust gas passage 2, the heat transfer characteristics of the inner wall of the exhaust gas passage 2 are poor, and the heat amount of the exhaust gas cannot be efficiently recovered. Furthermore, no significant sound reduction effect could be expected because the exhaust gas flow travels straight.

OBJECTS OF THE INVENTION In view of the conventional problems, an object of the present invention is to provide a low-noise, high-efficiency muffler-type exhaust gas heat exchanger.

Structure of the Invention The present invention provides a muffler-type exhaust gas system in which a plurality of types of exhaust gas pipes are provided in a water chamber, and a pipe having a plurality of holes in the circumferential direction is inserted into the exhaust gas pipe from the inlet side. The present invention is a heat exchanger, and is also intended for a structure in which a plurality of exhaust gas pipes into which the pipes are inserted are connected in a water chamber.

DESCRIPTION OF EMBODIMENTS A specific description will be given below using the drawings. Second
The figure shows a first embodiment of the heat exchanger of the present invention, and the heat exchanger is composed of a water chamber 3, an exhaust gas pipe line 4, and an exhaust gas pipe 5, and the tip of the exhaust gas pipe 5 is closed. , and the fluid such as exhaust gas is
A plurality of jet ports 6 are provided around the exhaust gas pipe 5 so as to collide with the inner wall of the exhaust gas pipe line 4 . When exhaust gas is sent from a combustion device such as an engine, it passes through the exhaust gas pipe 5, which is the inlet of the heat exchanger, and then flows toward the inner wall of the exhaust gas pipe 4 through the jet nozzle 6 provided around the exhaust gas pipe 5. , erupts at high speed. At this time, since the gas flow velocity is high and the gas flow collides almost perpendicularly with the inner wall of the exhaust gas pipe 4, the development of a boundary layer is also suppressed and the heat transfer characteristics can be promoted. Furthermore, when used as an exhaust gas heat exchanger for an engine, it is expected that the pulsating flow will promote heat transfer. The exhaust gas flow that collides with the inner wall of the exhaust gas pipe 4 from the jet port 4 passes through the tail pipe 7 of the exhaust gas pipe 4 and is discharged to the outside of the heat exchanger. Here, too, by narrowing the diameter of the tail pipe 7, The flow rate of the exhaust gas passing through the tail pipe 7 can be increased, and the heat transfer characteristics can be improved. The sound reduction characteristics can also be improved by changing the jetting direction of the passing fluid with respect to the transmission direction at the jetting port 6 and by narrowing the diameter of the tail pipe 7. The water in the water chamber 3 around the exhaust gas pipe 4 also contributes to improving the sound insulation properties. Further, by closing the tip of the exhaust gas pipe, the velocity of the flow colliding with the inner wall of the exhaust gas pipe line 4 can be increased.

Next, the second embodiment of the heat exchanger of the present invention will be described in the third embodiment.
As shown in the figure. In Figure 3, the heat exchanger is water chamber 1.
4, first exhaust gas pipe line 15, first exhaust gas pipe 1
6, first spout 17, second exhaust gas pipe 18, second
Exhaust gas pipe 9, second outlet 10, third exhaust gas pipe 11, third exhaust gas pipe 12, third outlet 13
It consists of

In this way, multiple exhaust gas pipes can be housed compactly in the water chamber, and not only can the temperature distribution in the water chamber be made uniform, but also by connecting them in series, a multi-stage muffler configuration can be created, reducing the It becomes possible to improve sound characteristics. In addition, multiple stages of exhaust gas pipes can be housed compactly within the water chamber, which not only equalizes the temperature distribution within the water chamber, but also creates a multi-stage muffler configuration by connecting them in series, improving sound reduction characteristics. It is possible to do so.

In the above embodiment, the exhaust gas pipes were connected through the connection chamber (second exhaust gas pipe 18), but this chamber was omitted and the exhaust gas pipes were connected directly to the first exhaust gas pipe 15.
Connect the tail pipe part (thin diameter part) to the third exhaust gas pipe 1.
It may be configured to connect to 2. Further, instead of forming the exhaust gas pipe by folding back into the water chamber, it may be connected in series in one direction.

Effects of the Invention As described above, the heat exchanger of the present invention has a high ejection flow velocity to the inner wall of the exhaust gas pipe and collides vertically with the fluid, which suppresses the formation of a boundary layer and improves heat transfer characteristics. It is possible to
Further, by narrowing the diameter of the tail pipe of the exhaust gas pipe, the passing fluid velocity can be increased and the heat transfer characteristics can be promoted. Furthermore, the sound reduction properties can be improved by changing the ejection direction of the passing fluid almost perpendicularly to the permeation direction and narrowing the diameter of the tail pipe.In this case, the water in the water chamber is also sound-insulated. Involved in improving characteristics. In particular, by connecting multiple types of exhaust gas pipes in series, it is possible to accurately reduce engine noise and the like having complex frequency characteristics.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a conventional heat exchanger,
FIGS. 2 and 3 are diagrams showing the configuration of heat exchangers according to different embodiments of the present invention. 3... Water chamber, 4... Exhaust gas pipe, 5... Exhaust gas pipe, 6... Spout, 7... Tail pipe.

Claims (1)

[Claims] 1. An exhaust gas pipe in which a plurality of types of exhaust gas pipes each having a thick part and a thin part are connected in series in a water chamber, and the part with a large diameter has a plurality of ejection ports in the circumferential direction. A heat exchanger for exhaust gas, characterized in that the exhaust gas is provided with and allows exhaust gas to flow into the exhaust gas pipeline via the exhaust gas pipe. 2. A chamber is provided at the mutual connection of the exhaust gas pipes into which the exhaust gas pipe is inserted, the exhaust gas pipe is connected to the narrower diameter part of the exhaust gas pipe in the previous stage, and a separate exhaust gas pipe is arranged at a distance from the exhaust gas pipe. 2. The exhaust gas heat exchanger according to claim 1, wherein the exhaust gas heat exchanger is connected to the next stage exhaust gas pipe through the exhaust gas pipe.