JPS62162765A - Fuel oil feeder for internal combustion engine of marine vessel - Google Patents

Abstract

PURPOSE:To prevent the boiling of the fuel oil in an air separator by installing a heat exchanger for carrying out the heat exchange between the excessive fuel oil having a high temperature which is returned into the air separator and the low temperature fuel oil supplied into a fuel oil cleaner. CONSTITUTION:The excessive fuel oil which is not consumed in an internal-com bustion engine 10 out of the fuel oil heated to a high temperature by a secon dary fuel heater 9 is returned with high temperature into a heat exchanger 15. The high temperature fuel oil returned into the internal-combustion engine 10 is cooled by the heat exchange with the low temperature fuel oil supplied into a fuel oil cleaner 4 by a fuel oil feeding pump 2, and returned into an air separator 12. While, the low temperature fuel oil inhaled from a fuel oil storage tank 1 by the fuel oil feeding pump 2 absorbs the calorific heat of the returned fuel oil having a high temperature which is returned from the internal-combustion engine 10 by the heat exchanger 15, and preheated and sent into a fuel oil heater 3. Therefore, the blowing-up of the oil from an air vent pipe 14 due to the boiling of fuel oil in the air separator 12 can be prevented.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a fuel oil supply system for a marine internal combustion engine.

[Conventional technology]

FIG. 4 shows a conventional device of this type. The fuel oil stored in the fuel oil clarifying tank 1 is sent to the fuel oil heater 3 by the fuel oil supply pump 2, where it is heated to 90 to 98°C, and the fuel oil is removed by the fuel oil purifier 4 to remove moisture, sludge, etc. is removed,
It is stored in the fuel oil regular tank 5. Fuel oil regular tank 5
Fuel oil (i.

It is mixed with high temperature surplus fuel oil returned from the internal combustion engine 10 via the pressure regulating valve 11 in the air separator 12.

The fuel oil is sucked in by the secondary fuel oil supply pump 8 and heated to a high temperature by the secondary fuel oil heater 9 so as to have the viscosity required by the internal combustion engine 10. A portion of the fuel oil sent to the internal combustion engine 10 is used for combustion by the internal combustion engine, but excess fuel oil is returned to the air separator 12 via the pressure regulating valve 11. The pressure regulating valve 11 is used to maintain the internal combustion engine inlet fuel oil pressure at a necessary constant pressure.

FIG. 5 shows the same conventional apparatus, but with a so-called pressurizing device installed as a countermeasure against loose oil. That is.

The fuel oil in the fuel oil regular tank 5 is supplied to the primary fuel oil supply tank 7.
``6'' and sent to the secondary fuel oil supply pump 8. At this time, the pressure on the discharge side of the secondary fuel oil supply pump 6 is reduced by approximately 5 to 9 by a pressure regulating valve 7 provided in the same line.
The pressure is kept constant at about /crn. Secondary fuel oil supply? Excess fuel oil discharged from the fuel tank f8 is returned to the air separator 12 by a device similar to that shown in FIG.

In FIG. 5, the air separator 12 is normally pressurized to about 5 kg/11n2 by the primary fuel oil supply pump and pressure regulating valve 7. The purpose of pressurizing is to prevent water in the fuel oil in the air separator from boiling.

The pressure is such that the boiling point is higher than the heating temperature of the fuel oil. The air relief valve 13 releases the gas in the air separator to the atmosphere through the air vent pipe 14, and usually a float type automatic relief valve or the like is used.

[Problem that the invention seeks to solve]

When low-quality heavy oil is used as fuel oil, the fuel oil at the inlet of the internal combustion engine usually needs to be heated to about 150°C.
This high temperature brings about various disadvantages. (1) Since the fuel oil is heated above its boiling point, the fuel oil may be blown up from the air pipe of the air separator due to an air boiling phenomenon.

(2) In order to prevent the above, it is necessary to employ a fuel oil pressurizing device as shown in FIG. 5, as an example.

The pressure of the air separator needs to be adjusted to correspond to the heating temperature of the fuel oil, but it is possible to increase the pressure, reducing the cost of upgrading the piping system and upgrading the secondary fuel supply pump. Invite up.

(3) When a fuel oil pressurizing device is adopted, if the air release valve with air separator fails, the fuel oil will blow up from the air pipe 14, but the higher the set pressure, the faster it will blow up. Become.

[Means for solving problems]

An object of the present invention is to provide a fuel oil supply system that eliminates the above-mentioned drawbacks, and is characterized by a fuel oil supply system for a marine internal combustion engine.

Heat exchange is performed between the high-temperature surplus fuel oil returned to the air separator from the internal combustion engine and the low-temperature fuel oil sucked from the fuel oil soaking tank by the fuel oil supply pump and supplied to the fuel oil purifier. A heat exchanger is provided which lowers the temperature of the high temperature surplus fuel oil returned to the air separator and recovers the amount of heat released at that time to preheat the fuel oil supplied to the fuel oil purifier. It is.

[Effect]

In this case, (1) return fuel oil from the internal combustion engine can be cooled and guided to the air separator, thereby preventing boiling in the air separator. On the other hand, the fuel oil cooler also functions as a fuel oil preheater. (2) Since boiling of the air separator can be prevented by adopting the present invention, there is no need for the pressurizing device shown in FIG. 5.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an explanatory diagram showing a fuel oil supply device of a first embodiment according to the present invention.

The overall configuration is similar to the conventional one shown in FIG.

A heat exchanger 15 is provided.

The fuel oil stored in the fuel oil tank l is sucked by the fuel oil supply pump 2 and transferred to the newly installed heat exchanger 15.
The fuel is sent to a fuel heater 3 and then to a fuel oil purifier 4 where it is processed and sent to a fuel oil regular tank 5. The fuel oil in the fuel oil regular tank 5 is fed by gravity to the air separator 12, and the secondary fuel oil supply pump f8. Furthermore, the surplus fuel oil is sent to the internal combustion engine 10 via the secondary fuel oil heater 9, and the excess fuel oil passes through the pressure regulating valve 11, undergoes heat exchange in the newly installed heat exchanger 15, and is sent to the air separator 12. be returned.

The operation of the newly installed heat exchanger 15 will be described.

Among the fuel oil heated to a high temperature by the secondary fuel oil heater, surplus fuel oil that is not consumed by the internal combustion engine 10 returns to the heat exchanger 15 while remaining at a high temperature.

Here, the high temperature fuel oil returned from the internal combustion engine is cooled by performing fuel exchange with the low temperature fuel oil sent to the fuel oil purifier 4 by the fuel oil supply pump 2 and returned to the air separator.

On the other hand, the low-temperature fuel oil sucked from the fuel oil tank/tank by the fuel oil supply pump 2 absorbs the heat of the high-temperature return fuel oil from the internal combustion engine 10 through the heat exchanger 15, and is preheated and sent to the fuel oil heater. Sent.

That is, the heat exchanger 15 acts as a cooler for the fuel oil returned from the internal combustion engine, lowers the temperature of the fuel oil in the air separator 12, and eliminates problems such as oil blowing up from the separator. On the other hand, it acts as a heater for the low-temperature fuel oil sent from the fuel oil supply pump.

FIG. 2 shows a second embodiment of the device according to the invention.

That is, this is an embodiment of a fuel oil supply device provided with a fuel oil pressurizing device. The operation of the heat exchanger 15 is the same as in the embodiment of FIG.

FIG. 3 shows a third embodiment of the apparatus according to the invention.

This is a further development of the device shown in FIG. That is.

The high temperature fuel oil returned from the internal combustion engine 10 is cooled by the heat exchanger 15, so it can be returned directly to the fuel oil regular tank 5 without providing a dedicated air separator.
Give an example.

〔Effect of the invention〕

The above case has the following effects.

(1) High-temperature surplus fuel oil returned from the internal combustion engine flows into the air separator while still at high temperature, and is mixed with relatively low-temperature fuel oil replenished from the fuel oil regular tank, resulting in an air-boiling phenomenon. Prevents oil from blowing up from the air vent pipe.

(2) The newly installed heat exchanger recovers the heat from the high-temperature surplus fuel oil and also serves as a preheater for the fuel oil purifier.

(3) Since boiling in the air separator can be prevented by the present invention, there is no need to employ the fuel oil heating device shown in FIG.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing a fuel oil supply system according to a first embodiment of the present invention, FIG. 2 is an explanatory diagram showing a fuel oil supply system according to a second embodiment according to the present invention, and FIG. FIG. 4 is an explanatory diagram showing a fuel oil supply device according to the third embodiment, FIG. 4 is an explanatory diagram showing a conventional fuel oil supply device, and FIG. 5 is an explanatory diagram showing a fuel oil supply device provided with a conventional pressurizing device. . 1... Fuel oil tank, 2... Fuel oil supply pump. 4...Fuel oil purifier, 10...Ship internal combustion engine, 12
...Air separator, 15...Heat exchanger. Engineering C 1] Wo! ,; 11-Lot 4...Fuel oil purifier 10...Ship internal combustion engine 12...Air separator 15...Heat exchanger

Claims (1)

[Claims] 1. In a fuel oil supply system for a ship's internal combustion engine, high-temperature surplus fuel oil is returned from the internal combustion engine to the air separator, and low-temperature surplus fuel oil is sucked from the fuel oil clarifying tank by the fuel oil supply pump and supplied to the fuel oil purifier. Heat exchange is performed with the fuel oil to lower the temperature of the high temperature surplus fuel oil returned from the internal combustion engine to the air separator, and the amount of heat released at that time is recovered and supplied to the fuel oil purifier. A fuel oil supply device for a marine internal combustion engine, characterized in that it is provided with a heat exchanger for preheating fuel oil.