JPS6338525B2 - - 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 In recent years, reflecting trends in energy conservation, systems such as the one shown in Figure 1 have been devised to improve overall energy efficiency by recovering heat from exhaust gas from engines, etc. This system extracts shaft output from an engine 1 as power, recovers waste heat in a heat exchanger 2, and exhausts it through a muffler 3. However, in such a system,
The heat exchanger 2 and muffler 3, which recover exhaust heat from the engine 1, are installed separately, making the system complex and transmitting a large amount of sound from the muffler 3 itself, which requires the muffler 3 to be large. There were some drawbacks such as not being able to do so. In addition, conventional heat exchangers for exhaust heat recovery are often of the fin type as shown in Figure 2, but the flow of exhaust gas from the engine is a pulsating flow, and in this type of heat exchanger, the effect of the pulsating flow is cannot make full use of it. moreover,
When trying to increase the efficiency of exhaust heat recovery, there are problems such as condensation of exhaust gas, progression of corrosion on the fin surface, and rapid deterioration of heat exchange performance due to the thinness of the fins. It was hot.

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

Structure of the Invention The present invention provides an exhaust gas space inside a water chamber containing a fluid to be heated, divides the exhaust gas space into a plurality of parts by a partition plate, and includes a heat exchanger tube through which the fluid to be heated passes through the inside of the exhaust gas space.
At least one double pipe with the outside also serving as an exhaust gas pipe,
This is a heat exchanger configured to penetrate through a partition plate, and is also intended for a configuration in which the length of the exhaust gas pipe is arbitrarily changed.

DESCRIPTION OF EMBODIMENTS FIG. 3 shows an embodiment of the heat exchanger of the present invention. The outside of the heat exchanger is surrounded by a water chamber 4, and an exhaust gas space 5 is provided inside the water chamber 4.

The exhaust gas space 5 is divided by a plurality of partition plates 6, and the water chamber 4 is provided with a water introduction pipe 7, and the header 8 is communicated with the water chamber 4 through a water hole 9. A water discharge pipe 11 is attached to 10. Furthermore, a heat exchanger tube 12 passes through the partition plate 6 and communicates the header 8 with the header 10. The portion penetrating the partition plate 6 is a double pipe with a heat transfer tube 12 on the inside and an exhaust gas pipe 13 on the outside, and the length of the exhaust gas pipe 13 can be changed arbitrarily. Further, the exhaust gas space 5 is provided with an exhaust gas introduction pipe 14 and an exhaust gas discharge pipe 15.

Next, its operation will be explained. First, the fluid to be heated passes through the water chamber 4 from the water introduction pipe 7,
The water enters the header 8 from the water hole 9, branches into the heat transfer tube 12, flows through the header 10, and then flows through the water discharge pipe 11.
more excreted. On the other hand, exhaust gas from an engine or the like, which is a heating fluid, enters the exhaust gas space 5 through the exhaust gas introduction pipe 14, then passes through the exhaust gas pipe 13 forming a double pipe, and then passes through the exhaust gas discharge pipe 1.
It is discharged from 5. At this time, the exhaust gas directly collides with the inner surface of the water chamber 4 and the heat transfer tube 12 or passes through the double tube, thereby effectively exchanging heat. The exhaust gas space 5 is divided into a partition plate 6
However, by changing the length of the exhaust gas pipe 13 for this subdivided space, the exhaust gas pipe 13
By reducing the distance between the opening end of the partition plate 6 and the partition plate 6, exhaust gas does not pass through the space without passing through the partition plate 6.
The heat exchange and sound reduction performance can be improved because the air collides with the air and detours to the upstream side. Further, according to this embodiment, exhaust gas enters the exhaust gas space 5 and enters the exhaust gas pipe 13 forming a double pipe, but here,
The flow is rapidly contracted to form an expansion type muffler, and furthermore, the exhaust gas space 5 is divided into a plurality of sections, thereby creating a multi-stage expansion type muffler effect. Since the exhaust gas pipe 13 protrudes into each space, it can also be used as a muffler to achieve the sound reduction effect of an internally inserted pipe type, and by changing the length of the exhaust gas pipe 13, the noise characteristics of the engine etc. can be reduced. It is also possible to create suitable sound reduction characteristics. Furthermore, moving the partition plate 6 is also an effective means for arbitrarily changing the sound reduction characteristics. Furthermore, in this embodiment, since the exhaust gas space 5 is surrounded by the water chamber 4 having a large mass, the sound insulation effect can be enhanced. In addition, regarding heat exchange performance, exhaust gas passes through the narrow space inside the double pipe at high speed, which suppresses the development of a boundary layer and significantly improves heat transfer characteristics. Moreover, by detouring the exhaust gas within the exhaust gas space, the substantial contact area can be increased. If we tried to further increase the waste heat recovery efficiency, condensed water would be generated and corrode the heat exchanger surface, but in this example, the flow is high speed, so
Condensed water can be spouted outside without accumulating, and corrosion can be suppressed. Further, in this embodiment, a cooperating hole 16 is provided to form a cooperating muffler, and it is also possible to reduce low-frequency sounds that are difficult to reduce with an expansion type muffler.

Effects of the Invention As explained above, the heat exchanger of the present invention has an expansion type muffler structure with multi-stage insertion tubes, so it has an excellent sound reduction effect and can easily cope with different noise characteristics such as engines. can be dealt with. In addition, heat transfer characteristics can be improved by suppressing the development of a boundary layer, and the contact area can be increased by bypassing exhaust gas. Furthermore, since the heat exchanger has a muffler-type configuration, the system can be simplified, and the double-tube structure allows the heat exchanger itself to be made smaller.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of an engine system equipped with an exhaust heat recovery heat exchanger, Fig. 2 is a configuration diagram of a conventional fin type heat exchanger, and Fig. 3 is a configuration diagram of a heat exchanger according to an embodiment of the present invention. It is a diagram. 4...Water chamber, 5...Exhaust gas space, 6...Partition plate, 12
...heat exchanger tube, 13...exhaust gas pipe.

Claims (1)

[Claims] 1. An exhaust gas space is provided inside the water chamber containing the fluid to be heated, and the exhaust gas space is divided into a plurality of parts by a partition plate, and at least one double pipe is installed, with the inside serving as a heat transfer tube and the outside serving as an exhaust gas pipe. , for the partition plate,
A heat exchanger characterized in that the exhaust gas pipe portion of the double pipe is divided and opened to different exhaust gas spaces.