JPS608697A - Heat exchanger of marine engine - Google Patents

Abstract

PURPOSE:To further increase the cooling efficiency of a heat exchanger, by making the cooling water to cool an engine stagger through a casing, and circulate through heat transfer tubes without fail, by providing baffle plates which are to be fixed to the heat transfer tubes through which fluid in low temperature passes, of flexible material. CONSTITUTION:Baffle plates 11 are fixed to heat transfer tubes 5 at specified intervals. The cooling water from an engine is led inside from flow inlet ports 10a formed at the end of a casing 10. The cooling water circulates through heat transfer tubes 5 to cool them, staggering through the casing 10, turned its flowing direction by each baffle plate 11. The cooling water is cooled in such a manner, is led outside from flow outlet ports 10b formed at the opposite end of a casing 10, and is fed into the engine. The baffle plates 11 are made of flexible material such as synthetic resin, in a semicircular shape. Holes 12 to insert heat transfer tubes 5 are provided in the baffle plates 11 having an interference to each hole.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat exchanger for a marine engine that indirectly cools the engine by cooling cooling water circulating through various parts of the engine through heat exchange.

Conventionally, in a small marine engine, heat transfer tubes for passing low-temperature seawater fluid are placed inside a casing through which fresh cooling water circulates through various parts of the engine, and the cooling water, whose temperature is rising as the engine is driven, is placed inside the casing. Some are equipped with a heat exchanger that indirectly cools the engine by contacting low-temperature heat transfer tubes to exchange heat as it passes through the casing, lowering the temperature of the cooling water and sending it to the engine. Baffle plates are placed on the heat exchanger tubes of this heat exchanger at predetermined intervals, and when the cooling water passes through the casing, the flow direction is changed by the baffle plates, and the flow is meandered between the heat exchanger tubes for cooling. There are things that aim to improve efficiency.

By the way, if there is a gap between the fitting part of this baffle plate and the heat transfer tube, the cooling water will flow through this gap and the direction of the flow cannot be changed sufficiently. I have to. However, inserting a large number of heat transfer tubes into the baffle plate and joining each fitting part with a solder or solder requires a lot of work, and it is difficult to uniformly attach the solder or IJ. Met.

This invention was made against the background of this situation, and it is possible to join the baffle plate and the heat exchanger tube with a simple structure without any gaps.
To provide a heat exchanger for a marine engine in which the direction of cooling water is reliably changed by a baffle plate, cooling efficiency is improved, and the two can be joined without using special means and workability is good.

In order to achieve the above object, the present invention is characterized in that the baffle plate is formed of a flexible material, and the heat exchanger tube is closely fitted to the baffle plate.

Hereinafter, embodiments of the present invention will be described in detail based on the drawings. First, the embodiment shown in FIGS. 1 to 4 will be described. FIG. 1 shows a small marine engine, and this engine A is equipped with a heat exchanger B that cools fresh water that cools each part of the engine. ing. The cooling water whose temperature has increased as it circulates through various parts of the engine A is supplied from the cooling water discharge pipe 1 to the heat exchanger B, and as it passes through the heat exchanger B, it is cooled by heat exchange. Then, the cooling water is returned to the engine A through the cooling water supply pipe 2 to indirectly cool the engine A. Low-temperature seawater fluid is supplied to the heat exchanger B through a seawater supply pipe 3, and this seawater passes through a heat exchanger pipe 5 made of brass or the like disposed in a casing 4, and then flows into the seawater provided on the opposite side of the casing 4. Water is drained from the discharge pipe 6.

The exhaust path C of the engine A includes an exhaust pipe 8 connected to a collecting pipe 7 through which exhaust gas from each main cylinder is guided, and a rubber hose 9 connected to the exhaust pipe V8. The collecting pipe 7 has a drainage passage 7a, and the upstream side of this drainage passage 7a is connected to the seawater discharge pipe 6 of the heat exchanger B, while the downstream side merges with the exhaust pipe 8 and drains water from the engine A. The exhaust gas and the waste water from heat exchanger B are mixed, and the temperature of the exhaust gas is lowered before being discharged.

The heat exchanger B includes heat transfer tubes 5 that pass low-temperature fluid seawater into a casing 10 through which cooling water that circulates through each part of the engine λ passes.
A large number of heat transfer tubes 5 are provided, and baffle plates 11 are alternately provided on the heat transfer tubes 5 at predetermined intervals. Engine A
Cooling water is supplied from a cooling water discharge pipe 1 to a passage 12 on the outer periphery of the casing 10, and enters the inside through an inlet 10a formed at an end of the casing 10.

The direction of flow of the cooling water is changed by each baffle plate 11, and the cooling water flows through the heat exchanger tubes 5 while meandering inside the casing 10.
It circulates between the two and is cooled. The cooling water cooled in this way exits from the outlet 1, Ob formed at the opposite end of the casing 10, and is supplied to the engine A through the cooling water supply pipe 2.

The baffle plate 11 is made of a flexible material such as rubber or synthetic resin, and has a semicircular shape as shown in FIG. The baffle plate 11 has an insertion hole 12 through which the heat transfer tube 5 is inserted.
is formed with a tightening allowance. A plurality of heat exchanger tubes 5 are tightly fitted into the insertion holes 12, and there is no gap between the fitting portions of the two. As a result, the cooling water passing through the casing 10 does not flow through the fitting portion between the baffle plate 11 and the heat transfer tube 5, and the direction of the flow can be effectively changed, making cooling efficiency even more effective. can be raised.

Then, a stopper plate 13 is inserted into a suitable heat exchanger tube 5 and fixed by brazing or soldering 14, etc., and this heat exchanger tube 5 is
It is assembled by inserting it from the opposite side of the direction of cooling water flow. This stopper plate 13 prevents the baffle plate 11 from moving in the direction of the flow of cooling water. The work is extremely simple since it is only necessary to braze or solder (=l l) 4 to a suitable heat exchanger tube 5 and to fix the stopper plate 13 to the baffle plate 11.

FIG. 5 shows another embodiment for preventing the movement of the baffle plates 11, in which a guide pipe 15 having both ends bent in a suitable heat transfer tube 5 is inserted between each baffle plate 11. This eliminates the process of fixing by brazing or soldering, and can significantly reduce the number of man-hours.

FIGS. 6 and 7 show still another embodiment for preventing the movement of the baffle plate 11, in which the heat exchanger tube 5 is surrounded by a band 16,
The contact portion between the band 16 and the heat transfer tube 5 is fixed by brazing or soldering 14 or the like.

The heat transfer tube 5 is provided in the casing 10 at both ends thereof, with a gasket 19 made of rubber, synthetic resin, etc. interposed between an end plate 17 and a spacer 18. Then, the tightening port 20 is screwed onto the spacer 18 at several locations around the center and circumference of the end plate 17, and the tightening is fixed. By tightening the tightening port 20, the spacer 18 presses the gasket 19 toward the end plate 17. Therefore, the gasket 19 expands in the circumferential direction,
The gap between the heat exchanger tube 5 and the casing 10 is sealed and fixed. This eliminates the need for brazing or the like to connect the casing 10, heat exchanger tubes 5, and end plates 17, thereby reducing manufacturing man-hours and stabilizing quality. Furthermore, even if some parts that come into contact with seawater are damaged due to corrosion, they can be easily disassembled and replaced.

Furthermore, there is a heat exchanger B in which the heat exchanger main body and the casing are integrated, and the element is composed only of the end plate 17 and the heat transfer tube 5. In this case, as shown in FIG. 8, a short guide 21 is used to hold down the gasket 19 instead of the casing. Alternatively, as shown in FIG. 9, the end plate 17 may be formed into a cylindrical shape so that the spacer 18 can move along the inner surface 17a.

As described above, in this invention, the baffle plate provided on the heat transfer tube through which low-temperature fluid passes is formed of an NL material, and the heat transfer tube is tightly fitted and fixed to the baffle plate, so that the cooling water for cooling the engine The flow direction of the heat exchanger is reliably changed by the baffle plate, and the flow meanderes inside the casing to circulate between the heat transfer tubes, thereby further improving the cooling efficiency. The mounting structure of the baffle plate and heat exchanger tube is 1 mtJ:i, which allows the fitting parts to be tightly attached without using brazing or soldering as in conventional methods.
and reliable.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway front view showing this generator Ill, Fig. 2 is a cross-sectional front view of the heat exchanger, and Fig. 3 is ff12's ■-■
FIG. 4 is an enlarged sectional view of the fixing portion of the baffle plate and the heat exchanger tube, FIG. 5 is a sectional view showing another embodiment, and FIG. 6 is a side view showing still another embodiment. FIG. 7 is a sectional view of this embodiment, FIG. 8 is a sectional view of another embodiment for fixing the heat exchanger tubes, and FIG. 9 is a sectional view of this other embodiment. A... Engine B... Heat exchanger 5... Heat exchanger tube 10... Casing 11... Baffle plate l 3...
・Stopper 15... Guide pipe 16... Band patent applicant Yamaha Motor Co., Ltd. Figure 3 Figure 4 Figure 5 ]] 11 Figure 6 Figure 7 Figure 8 Figure 1

Claims (1)

[Claims] In the heat exchanger for a marine engine, the heat exchanger for a marine engine is provided with a heat transfer tube for passing low temperature fluid in a casing through which cooling water circulates through various parts of the engine, and a baffle plate for changing the flow direction of the cooling water is disposed on the heat transfer tube. A heat exchanger for a marine engine, in which a baffle plate is formed of a flexible material, and the heat transfer tube is tightly fitted to the baffle plate.