JPS5813065Y2 - Fresh water cooling system for cooling marine internal combustion engines - Google Patents

Description

[Detailed description of the invention] This invention relates to an improvement made to a device that attempts to cool the cooling fresh water of a marine internal combustion engine with seawater. The aim is to enable automatic and appropriate adjustment.

By the way, marine internal combustion engines that use a fresh water cooling system are equipped with a fresh water cooler in order to cool the fresh water used to cool the engine with seawater and make it reusable. Cooling water is circulated between the engine and the engine.

However, the pump for supplying cooling seawater to this fresh water cooler is usually driven by using the output of the engine, so the amount of supply is changed according to the fluctuations in the engine's rotation speed. However, in reality, the supply capacity is selected to ensure the necessary supply amount during high-speed, high-load operation of the engine.
When the engine is operating at low speed and under low load, for example when the engine is warming up or cruising at a slow speed, the supply amount tends to be excessive.

Such an oversupply of cooling seawater causes the cooling capacity of the fresh water cooler to become excessive, so for example, during warm-up operation after starting the engine in winter, it takes a considerable amount of time to raise the temperature of the cooling fresh water to around 60°C. It does not require a long time, and when cruising at slow speeds, incomplete combustion is likely to occur due to the engine being too cold.

The present invention addresses the above-mentioned conventional problems and makes it possible to automatically adjust the cooling capacity of the fresh water cooler to properly match the operating conditions of the engine. Two systems are prepared, and the cooling seawater is always supplied from one system, while the other system supplies cooling seawater according to the number of rotations of the propulsion shaft.

Hereinafter, an embodiment shown in the drawings will be described in detail.

In the figure, 1 is the hull, 2 is the main body of the marine engine mounted on it, 3 is a clutch with a reversing function attached to the main body, and 4
5 is a propulsion shaft connected to the driven side of the clutch, and 5 is a fresh water cooler for cooling fresh water for cooling with seawater.

The fresh water cooler 5 consists of an upper tank 6 and a heat exchange chamber 7, which are communicated through a through hole 8.

The upper tank 6 also includes a cooling water supply hole 10 that is closed with a lid 9 that also serves as a safety valve, and an inlet 11 for the cooling water that returns from the engine body 2 as shown by the white arrow.
The heat exchange chamber 7 has an outlet 12 for cooling fresh water that goes toward the engine body 2 as shown by the white arrow, a large number of water pipes 13 through which cooling seawater passes, and a plurality of water pipes arranged side by side so as to communicate with one end of each of the water pipes. A seawater outlet 15 provided to communicate with the first and second seawater populations 14a and 14b and the other end of each of the water pipes.
16 increases the length of the fresh water flow path in the room. It is a baffle board for

17a is a first seawater pump for pumping up cooling seawater, and a first pipe 19a connects the first Kingston tank 18a at the bottom of the hull 1 and the first seawater pump 14a of the fresh water cooler 5. A first seawater supply system A for the cooler is arranged as shown by the black arrow.

17b is a second seawater pump for pumping up seawater for cooling, and a pipe 19b connecting the second Kingston tank 18b at the bottom of the hull 1 and the second seawater pump 14b of the fresh water cooler 5; A second seawater supply system B for the cooler is interposed in the middle and is configured as shown by the black arrow.

Therefore, the above-mentioned both groove water supply systems A and B are connected in parallel to the fresh water cooler 5.

However, when the engine main body 2 is operating, the first seawater pump 17a is constantly driven, for example, using a part of its output, regardless of whether or not its output is being transmitted to the propulsion shaft 4. The second seawater pump 1 shall be
It is assumed that 7b is driven only when the output of the engine body 2 is being transmitted to the propulsion shaft 4, using, for example, a part of the output transmitted to the propulsion shaft 4.

In addition, 20 in the figure is a pipe line of the seawater discharge system C shown by the black arrow connected to the seawater outlet 15 of the fresh water cooler 5, and the tip thereof is connected to the seawater outlet 15 of the fresh water cooler 5, and the tip thereof is connected to the seawater outlet 15 of the fresh water cooler 5, and the tip thereof is connected to the seawater outlet 15 of the fresh water cooler 5. It is assumed that the hull 1 is open to the outside.

In the above-described configuration, if the engine body 2 is currently in operation but its output is not transmitted to the propulsion shaft 4, only the first seawater pump 17a is driven and the The seawater pumped up from the Kingston cock 18a of 1- is passed from the pipe 19a to the first seawater population 14 of the fresh water cooler 5.
Direct it to a.

Therefore, the fresh water cooler 5 at this time is supplied with cooling seawater only from the first seawater supply system A.

In such a state, if the output of the engine body 2 is transmitted to the propulsion shaft 4 via the clutch 3, a part of the transmitted output will also drive the second seawater pump 17b, The seawater pumped up from the second Kingston cock 18b is directed to the second seawater population 14b of the fresh water cooler 5 through the pipe 19b.

Therefore, the fresh water cooler 5 at this time is supplied with cooling seawater from the first and second groove water supply systems A and B.

However, the amount of cooling seawater supplied from the second seawater supply system B to the fresh water cooler 5 is determined by driving the second seawater pump 17b using a part of the engine output transmitted to the propulsion shaft 4. Since the rotation speed of the shaft changes, it changes depending on the rotation speed fluctuation of the shaft.

Similarly, the amount of cooling seawater supplied from the first seawater supply system A to the fresh water cooler 5 is also controlled by the first seawater pump 1.
When 7a is driven by directly utilizing a part of the engine output, it changes according to the rotational speed fluctuation of the engine.

However, in any case, the amount of cooling seawater supplied to the fresh water cooler 5 will be automatically adjusted according to the operating condition of the engine body 2, and for example, the amount of seawater supplied for cooling to the fresh water cooler 5 will be adjusted automatically according to the operating state of the engine body 2. It is small when operating under load, increases slightly when operating under load and cruising at a slow speed, and increases further as the cruising speed increases.

As described above, the present invention provides two systems for supplying cooling seawater to the fresh water cooler, and one supply system constantly supplies the cooling seawater necessary for the fresh water cooler while the engine is operating. According to the present invention, the amount of cooling seawater supplied to the fresh water cooler can be adjusted according to the number of rotations of the propulsion shaft from the other supply system. The fresh water cooling capacity of the cooler can be automatically and appropriately adjusted to closely follow the required amount that changes depending on the operating condition of the engine. Therefore, the situation where the cooling capacity becomes excessive during low-speed, no-load operation can be avoided, and engine warm-up can be completed in a short time even in winter, and incomplete combustion of the engine can be prevented during slow-speed cruising. The engine can be effectively prevented from overheating, and during high-speed, high-load operation, the necessary and sufficient cooling capacity can be obtained, and there is no risk of engine overheating.

[Brief explanation of the drawing]

FIG. 1 is a side view showing an embodiment of the present invention, and FIG. 2 is an enlarged cutaway side view showing a specific example of a fresh water cooler used in the embodiment. A...First seawater supply system, B...Second seawater supply system, 1...Hull, 2...Engine body, 4... ...Propulsion shaft, 5... Fresh water cooler, 17a... First seawater pump, 17b.
...Second seawater pump.

Claims (1)

[Scope of utility model registration request] a first seawater supply system equipped with a first seawater pump that is constantly driven during operation of the marine internal combustion engine; A second seawater supply system equipped with a second seawater pump driven by a seawater pump is provided, and the above-mentioned double-channel water supply system is used for a fresh water cooler for cooling fresh water for cooling with seawater. A fresh water cooling device for cooling a marine internal combustion engine, characterized in that the devices are connected in parallel.