JP2013181417A - Fuel supply system for marine vessel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact and effective constitution of a fuel supply system for supplying fuel to an engine for a marine vessel.SOLUTION: A first fuel tank 7 stores first fuel. A second fuel tank 9 stores second fuel whose viscosity at a normal temperature is lower than that of the first fuel. A fuel heater 8 heats the first fuel and supplies the same to a diesel engine 2. A fuel cooler 10 cools the second fuel and supplies the same to the diesel engine 2. The fuel cooler 10 cools the second fuel using a Peltier element. A first fuel return channel 36 returns the first fuel to the first fuel tank 7 from the diesel engine 2 via the fuel cooler 10. Further, the fuel cooler 10 generates power by the Peltier element when the first fuel returned from the diesel engine 2 passes through the same.

Description

  The present invention relates to a marine fuel supply system that supplies a plurality of types of fuel to a marine engine.

  Conventionally, a fuel with many impurities, such as A heavy oil and C heavy oil, is used for marine fuel. However, in recent years, regulations on SOx (sulfur oxide) emissions have been strengthened in some sea areas as part of countermeasures against environmental pollution by marine diesel engines. Against the backdrop of such regulations, there is a movement to use marine gas oil (MGO), which is a low sulfur fuel, as a marine fuel.

  By the way, there is an allowable range for the viscosity of the fuel supplied to the engine, and problems may occur if fuel having a viscosity outside the allowable range is supplied to the engine. For example, C heavy oil that has been used conventionally has a viscosity that is too high at room temperature, and therefore it has been necessary to lower the viscosity by heating with a heater before supplying it to the engine.

  On the other hand, fuels with few impurities, such as the above-mentioned marine gas oil, have a lower viscosity than conventional marine fuels such as C heavy oil. In addition, since the temperature of the fuel gradually increases while the engine is operating, the viscosity of the fuel decreases. If the viscosity of the fuel supplied to the engine is too low, a sufficient oil film is not generated between the plunger and the barrel of the fuel injection pump, which may cause a failure.

  In this regard, although in the field of construction machinery, Patent Document 1 discloses a configuration in which a fuel cooler that operates to increase the viscosity of fuel is provided in a fuel supply path from a fuel tank to an engine. According to Patent Document 1, it is possible to increase the viscosity of the fuel supplied to the engine and avoid the loss of the lubricating function of the fuel due to the viscosity being too low.

Japanese Patent Laid-Open No. 11-324831

  In Patent Document 1, the fuel cooler is an air-cooled type. If it is a construction machine, air outside the vehicle can be taken in as cooling air, so it can be said that it is a natural idea to configure the fuel cooler to be air-cooled. However, in a ship, an engine room in which an engine or the like is arranged is relatively hot (around 45 ° C.) even if it is constantly ventilated. Therefore, it is considered that an air-cooled fuel cooler cannot exhibit a sufficient cooling effect in the engine room.

  Therefore, in a ship or the like, for example, it is conceivable to use a fuel cooler using a refrigerant gas such as HFC. However, when HFC or the like is used as the refrigerant, a mechanical drive unit (compressor, motor, etc.) is required, which causes vibration and noise and requires regular maintenance. In addition, a fuel cooler having a compressor or the like is difficult to reduce in size because of its complicated structure, and is difficult to employ for a small engine. Furthermore, the use of greenhouse gases such as HFC also has problems in terms of measures against global warming.

  In this regard, fuel coolers mounted on ships are known that use seawater as a refrigerant. In this type of fuel cooler, seawater is pumped up and used as a refrigerant, and the used seawater may be discharged again into the sea. The fuel cooler with this configuration eliminates the need for a compressor and the like, and there is no problem due to the use of greenhouse gases. However, since the cooling performance of the fuel cooler having this configuration depends on the seawater temperature, the fuel cooler cannot exhibit sufficient cooling performance in a sea area (such as a tropical sea) where the seawater temperature is high. Moreover, the heat exchanger which flows seawater must be comprised with corrosion-resistant materials, such as titanium, and a manufacturing cost will become high. Furthermore, when the heat exchanger fails, the fuel may flow out into the seawater. Even if a compressor or the like is not required, a pump and a heat exchanger for pumping seawater are required, and it is still difficult to reduce the size of the fuel cooler.

  In particular, in recent years, regulations on sulfur oxide emissions in specific sea areas have become stricter, and therefore, there is a demand for a fuel supply system that can switch the fuel used in accordance with the sea area to be navigated. However, the fuel supply system configured to switch a plurality of fuels as described above tends to increase in size and complexity. In a fuel supply system that switches and supplies a plurality of fuels, a configuration for supplying other fuels while supplying a certain fuel to the engine is not used. For example, while supplying high-viscosity fuel to the engine, a fuel heater is used to heat the fuel to lower the viscosity, and a fuel cooler is not used. On the other hand, while a low-viscosity fuel is supplied to the engine, a fuel cooler is used to cool the fuel and increase the viscosity, and a fuel heater is not used.

  In this way, the fuel supply system that switches multiple fuels and supplies them to the engine tends to increase in size, and is partly unused during actual operations, improving efficiency. There is room for.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a small and efficient configuration of a fuel supply system that supplies fuel to a marine engine.

Means and effects for solving the problems

  The problems to be solved by the present invention are as described above. Next, means for solving the problems and the effects thereof will be described.

  According to an aspect of the present invention, a marine fuel supply system having the following configuration is provided. That is, the marine fuel supply system includes a first fuel tank, a second fuel tank, a fuel heater, a fuel cooler, and a supply fuel switching unit. The first fuel tank stores a first fuel. The second fuel tank stores a second fuel having a viscosity at room temperature lower than that of the first fuel. The fuel heater heats the first fuel and supplies it to the engine. The fuel cooler cools and supplies the second fuel to the engine. The supply fuel switching unit switches so as to supply either the first fuel from the fuel heater or the second fuel from the fuel cooler to the engine. In addition, the marine fuel supply system includes a first fuel passage that allows the first fuel to flow to the fuel cooler when the first fuel is supplied to the engine. The fuel cooler is configured to cool the second fuel using a Peltier element, and generates electricity by the Peltier element when the first fuel passes.

  As described above, by using the Peltier element for the fuel cooler, the fuel cooler can be simplified, noise can be reduced, and the apparatus can be downsized. Further, the first fuel heated by the fuel heater is in a sufficiently high temperature state with respect to the room temperature of the engine room. Therefore, by flowing the high temperature first fuel through the fuel cooler, electric power can be obtained in the Peltier element of the fuel cooler.

  The marine fuel supply system is preferably configured as follows. That is, when the first fuel is supplied to the engine, the first fuel passage returns the first fuel remaining in the engine to the first fuel tank via the fuel cooler.

  As described above, by generating power with the fuel cooler using the first fuel returned from the engine, it is possible to effectively recover the excess heat as electric power. Moreover, it can avoid affecting the temperature of the 1st fuel supplied to an engine by generating electric power in a back | latter stage rather than an engine.

  The marine fuel supply system is preferably configured as follows. That is, the fuel heater is configured to heat the first fuel using steam generated by an exhaust heat recovery device that generates steam using exhaust heat of the engine.

  Generally, water vapor generated by the exhaust heat recovery apparatus is abundant in the ship. Therefore, by configuring as described above, a heat source of excess steam can be utilized and recovered as electric energy by the Peltier element. Thus, since heat energy that is difficult to use with water vapor can be easily converted into electric energy, energy can be effectively used.

1 is a block diagram of a marine fuel supply system according to an embodiment of the present invention. Front sectional drawing of a fuel cooler. Side surface sectional drawing of a fuel cooler. The front sectional view of the fuel cooler concerning a modification. Side surface sectional drawing of the fuel cooler which concerns on a modification.

  Next, a description will be given with reference to the drawings. FIG. 1 is a block diagram showing the flow of fuel in a marine fuel supply system 1 according to an embodiment of the present invention.

  The marine fuel supply system 1 is configured to be able to supply fuel to a diesel engine 2 of a marine vessel. The ship includes an engine room that houses the diesel engine 2. The marine fuel supply system 1 is disposed in the same engine room as the diesel engine 2.

  The diesel engine 2 is a drive source for driving the screw propeller 33 and the like of the ship. The diesel engine 2 is configured to drive the generator 34. With this generator 34, electric power can be supplied to various electric devices mounted on the ship. Further, the high-temperature exhaust gas discharged from the diesel engine 2 is configured to be supplied to an exhaust gas economizer (exhaust heat recovery device) 35. The exhaust gas economizer 35 is for recovering and effectively using the exhaust heat of the diesel engine 2. Specifically, the exhaust gas economizer 35 is configured to generate hot water and steam (steam) used in the ship by the heat of the exhaust gas.

  The diesel engine 2 includes a fuel jet pump 3. The marine fuel supply system 1 includes a first fuel supply path 4 that supplies a first fuel to a fuel injection pump 3 and a second fuel supply path 5 that supplies a second fuel to the fuel injection pump 3. ing. A supply fuel switching unit 6 is disposed between the first fuel supply path 4 and the second fuel supply path 5 and the fuel injection pump 3. The supply fuel switching unit 6 is configured to connect either the first fuel supply path 4 or the second fuel supply path 5 to the fuel ejection pump 3. Thereby, either the first fuel or the second fuel can be selected and supplied to the fuel injection pump 3 of the diesel engine 2.

  The first fuel is a fuel having a large amount of impurities and a high viscosity (C heavy oil in this embodiment). In addition, the second fuel is a fuel with less impurities and a low viscosity (marine gas oil in the present embodiment). By switching the supply fuel switching unit 6 in accordance with the emission regulation of the sea area where navigation is performed, the fuel corresponding to the emission regulation can be supplied to the diesel engine 2. That is, the diesel engine 2 uses the second fuel (marine gas oil), which is a low-sulfur fuel, in sea areas where sulfur oxide emission regulations are severe, and uses the first fuel (C heavy oil) in other sea areas. Can be driven. The supply fuel switching unit 6 can be switched by an appropriate operation of the operator.

  The first fuel supply path 4 includes a first fuel tank 7 and a fuel heater 8. The first fuel tank 7 stores a first fuel (C heavy oil) to be supplied to the diesel engine 2. The fuel heater 8 is disposed between the first fuel tank 7 and the supply fuel switching unit 6 and is configured to heat the first fuel supplied to the diesel engine 2. That is, since the viscosity of the first fuel (C heavy oil) is too high at the engine room temperature (about 45 ° C.), it cannot be supplied to the fuel injection pump 3 of the diesel engine 2 as it is. Therefore, the first fuel is heated to an appropriate temperature (for example, 130 ° C. or higher) by the fuel heater 8 so that the viscosity of the first fuel is adjusted to be within the allowable range of the fuel injection pump 3, and then the fuel ejection is performed. It is configured to supply to the pump 3. The fuel heater 8 is configured to heat the first fuel using the heat of water vapor supplied from the exhaust gas economizer 35. However, the configuration of the fuel heater 8 is not limited to this, and a known appropriate configuration such as an electric heater may be employed.

  The second fuel supply path 5 includes a second fuel tank 9 and a fuel cooler 10. The second fuel tank 9 stores a second fuel (marine gas oil) to be supplied to the diesel engine 2. The fuel cooler 10 is disposed between the second fuel tank 9 and the supply fuel switching unit 6, and is configured to cool the second fuel supplied to the diesel engine 2. That is, part of the fuel supplied to the diesel engine 2 returns to the fuel tank without being used. At this time, the temperature of the fuel is increased by the heat of the diesel engine 2. Therefore, when the second fuel (marine gas oil) is used in this environment, the viscosity decreases due to the temperature rise, and if the second fuel is supplied to the fuel injection pump 3 of the diesel engine 2 as it is, it may cause a problem. Therefore, the second fuel is cooled to an appropriate temperature (for example, 40 ° C. or less) by the fuel cooler 10 so that the viscosity of the second fuel is adjusted to be within the allowable range of the fuel injection pump 3, and then the fuel injection It is configured to supply to the pump 3. The configuration of the fuel cooler 10 will be described later.

  A temperature sensor 11 that measures the temperature of the fuel is disposed in the vicinity of the fuel inlet to the fuel injection pump 3. The marine fuel supply system 1 of the present embodiment is configured to heat or cool the fuel based on the temperature of the fuel measured by the temperature sensor 11. Thus, since the fuel is heated or cooled based on the temperature of the fuel immediately before being supplied to the diesel engine 2, the viscosity of the fuel supplied to the diesel engine 2 can be appropriately controlled.

  The surplus fuel in the diesel engine 2 is returned to the first fuel tank 7 or the second fuel tank 9. The marine fuel supply system 1 includes a return tank switching unit 12 that switches between returning the fuel to the first fuel tank 7 and the second fuel tank 9. That is, when the first fuel is used in the diesel engine 2, the fuel is returned to the first fuel tank 7, and when the second fuel is used, the fuel is returned to the second fuel tank 9. The return tank switching unit 12 may be switched by an operator's operation or automatically in conjunction with the switching of the supply fuel switching unit 6.

  Subsequently, the fuel cooler 10 of the present embodiment will be described with reference to FIGS. 2 and 3. The fuel cooler 10 includes a fuel passage 20, a heat transfer member 21, a Peltier element 22, and an air cooling unit 23.

  The fuel passage 20 is configured so that fuel can flow through the fuel passage 20. The fuel passage 20 is configured to connect the first opening 24 and the second opening 25 linearly. The second fuel in the second fuel tank 9 is introduced into the fuel passage 20 from the first opening 24, flows through the fuel passage 20, exits from the second opening 25, and is supplied to the fuel injection pump 3. .

  In the present embodiment, the fuel passage 20 has a flat shape. Specifically, as shown in FIG. 3, the fuel passage 20 is configured such that the flow path shape when cut along a plane orthogonal to the fuel flow direction is substantially rectangular. In the fuel cooler 10 of the present embodiment, the fuel passage 20 having a rectangular cross section is formed by surrounding four sides of the flow path with metal plates. As shown in FIG. 3, the metal plate constituting the wall surface corresponding to the long side of the rectangular fuel passage 20 is referred to as a ceiling plate 26 and a bottom plate 27. The metal plates constituting the wall surface corresponding to the short side of the rectangular fuel passage 20 are referred to as side plates 28 and 29. Each of the ceiling plate 26, the bottom plate 27, and the side plates 28 and 29 is a flat metal plate, and is configured such that fuel flows in a space surrounded by the metal plate. The ceiling plate, the bottom plate, and the like are names for convenience of explanation, and do not limit the vertical direction of the fuel passage 20.

  A plurality of heat transfer members 21 are arranged inside the fuel passage 20. In the present embodiment, the heat transfer member 21 is configured as a round bar member. The heat transfer members 21 are arranged at an appropriate interval so that fuel can flow between the heat transfer members 21.

  Each heat transfer member 21 is arranged so that its longitudinal direction is substantially orthogonal to the direction in which the second fuel flows in the fuel passage 20 (the direction from the first opening 24 to the second opening 25). ing. In the present embodiment, the heat transfer members 21 are arranged so that their longitudinal directions are substantially orthogonal to the ceiling plate 26 and the bottom plate 27. One end of each heat transfer member 21 is connected to the ceiling plate 26, and the other end is connected to the bottom plate 27. With this configuration, the heat of the fuel flowing in the fuel passage 20 can be transmitted to the wall surface (specifically, the ceiling plate 26 and the bottom plate 27) of the fuel passage 20 by the heat transfer member 21. Further, since both ends of the heat transfer member 21 are connected to the wall surface of the fuel passage 20 in the fuel cooler 10 of the present embodiment, compared to a case where only one end of the heat transfer member 21 is connected to the wall surface of the fuel passage 20, The heat of the fuel flowing in the fuel passage 20 can be efficiently transmitted to the wall surface (the ceiling plate 26 and the bottom plate 27) of the fuel passage 20.

  The material of the heat transfer member 21 is not particularly limited, but it is preferable that the heat transfer member 21 be made of a material having high thermal conductivity such as copper. However, copper may not be used for the heat transfer member 21 when the second fuel flowing in the fuel passage 20 is corrosive. In the fuel cooler 10 of the present embodiment, the heat transfer member 21 is made of an iron alloy having corrosion resistance with respect to the second fuel.

  In the fuel cooler 10 of this embodiment, since the heat transfer member 21 is made of an iron alloy, it cannot be said that the efficiency of transferring heat by the heat transfer member 21 is necessarily good. Therefore, the fuel cooler 10 of the present embodiment is configured such that the distance for transferring heat by the heat transfer member 21 is shortened. Specifically, it is as follows. That is, as described above, in the present embodiment, the fuel passage 20 is formed in a flat shape (the cross section of the flow passage is formed in a rectangular shape). And it arrange | positions so that the longitudinal direction of each heat-transfer member 21 may be followed along the short side of a rectangular flow-path cross section. Thereby, since the length of the heat transfer member 21 can be shortened, the temperature gradient in the longitudinal direction of the heat transfer member 21 becomes steep. As a result, even when the heat transfer member 21 is made of a material having a low thermal conductivity such as an iron alloy, the heat of the fuel flowing in the fuel passage 20 is efficiently transmitted to the ceiling plate 26 or the bottom plate 27. Can do.

  The Peltier element 22 is formed in a flat plate shape. In addition, since the Peltier element formed in flat shape in this way is a common thing, a commercially available Peltier element can be utilized. The Peltier element 22 has a known configuration in which, when energized, it takes heat from one side and cools it, and moves the taken heat to the other side. As shown in FIG. 2 and the like, the Peltier element 22 is attached to the outside of the wall surface of the fuel passage 20. Specifically, the Peltier element 22 is bonded to the outer surface of the ceiling plate 26 and the outer surface of the bottom plate 27, respectively.

  Since the ceiling plate 26 and the bottom plate 27 are formed in a flat plate shape, for example, compared with a case where the wall surface of the fuel passage 20 is curved, the wall surface (the ceiling plate 26 and the bottom plate 27) of the fuel passage 20 and the Peltier element 22 The contact area can be increased. Further, since the ceiling plate 26 and the bottom plate 27 constitute the long side of the fuel passage 20 having a rectangular cross section, the area is larger than the side plates 28 and 29 constituting the short side of the fuel passage 20. Therefore, the contact area between the wall surface (the ceiling plate 26 and the bottom plate 27) of the fuel passage 20 and the Peltier element 22 can be made larger than when the Peltier element 22 is attached to the side plates 28 and 29.

  In the Peltier element 22, the surface (inner surface) facing the fuel passage 20 side is a cooling surface, and the other surface (outer surface) is a heat radiating surface. The 20 wall surfaces (the ceiling plate 26 and the bottom plate 27) are configured to be cooled. As described above, the end of the heat transfer member 21 is connected to the ceiling plate 26 and the bottom plate 27. Therefore, the heat transfer member 21 can be cooled by cooling the ceiling plate 26 and the bottom plate 27 by the Peltier element 22. With the above configuration, the fuel flowing in the fuel passage 20 can be cooled.

  In the present embodiment, electric power for driving the Peltier element 22 is supplied from the generator 34 of the diesel engine 2. Therefore, it is not necessary to provide a dedicated power source for driving the fuel cooler 10.

  An air cooling unit 23 is disposed on the heat dissipation surface of the Peltier element 22. The air cooling unit 23 includes a heat sink 30 and a blower fan 31. The heat sink 30 is attached to the heat dissipation surface of the Peltier element 22. Thereby, the heat of the heat radiating surface of the Peltier element 22 can be released to the surrounding air by the heat sink 30. At this time, heat can be efficiently radiated from the heat sink 30 by blowing air to the heat sink 30 by the blower fan 31. In addition, the air-cooling part 23 is provided corresponding to the Peltier element 22 on the ceiling plate 26 side and the Peltier element 22 on the bottom plate 27 side, respectively. That is, the air cooling unit 23 is disposed so as to sandwich the fuel passage 20 having a rectangular cross section from the short side direction. Thereby, the heat of the fuel passage 20 can be efficiently radiated.

  With the above configuration, the heat of the fuel flowing through the fuel passage 20 is transmitted to the ceiling plate 26 and the bottom plate 27 via the heat transfer member 21. The heat of the ceiling plate 26 and the bottom plate 27 is moved to the heat sink 30 by the Peltier element 22 and is released from the heat sink 30 to the surrounding air. With the fuel cooler 10 configured in this manner, the second fuel can be efficiently cooled and supplied to the diesel engine 2.

  As described above, in the marine fuel supply system 1 of the present embodiment, the Peltier element 22 is employed in the fuel cooler 10. Thereby, the fuel can be cooled without using a refrigerant such as refrigerant gas or seawater. Therefore, since there is no mechanical drive unit such as a compressor, noise and vibration are not generated and maintenance is free. Moreover, since it is not necessary to take in the refrigerant outside the engine room such as seawater, it is possible to make an independent system in the engine room, and even if the fuel cooler is broken, the fuel leaks into the seawater. Don't worry. And since the mechanism for circulating a refrigerant | coolant becomes unnecessary, the fuel cooler 10 can be comprised compactly and simply.

  In addition, the appropriate temperature of the 2nd fuel (marine gas oil) supplied to an engine is 40 degrees C or less, for example. Accordingly, in the marine fuel supply system 1, when the second fuel is supplied to the diesel engine 2, for example, the following control may be performed. That is, when the temperature sensor 11 detects that the temperature of the second fuel is 40 ° C. or higher while the second fuel is being supplied to the diesel engine 2, the control device (not shown) performs the Peltier element 22. Is started, the fuel cooler 10 is driven, and the cooling of the second fuel is started. When the temperature sensor 11 detects that the temperature of the second fuel has reached a predetermined set temperature (less than 40 ° C.), the control device (not shown) cuts off the power supply to the Peltier element 22 and the fuel cooler 10 stops the cooling of the second fuel. Thus, by controlling the current to the Peltier element 22 based on the detection result of the temperature sensor 11, the temperature of the second fuel supplied to the diesel engine 2 can be adjusted easily and accurately. Therefore, the viscosity of the second fuel supplied to the diesel engine 2 can be appropriately controlled.

  By the way, since the fuel cooler 10 of this embodiment is the structure which releases heat with the air cooling part 23, the one where the temperature of the air around the said air cooling part 23 is as low as possible is desirable. However, the room temperature (about 45 ° C.) of the engine room in which the fuel cooler 10 and the like are disposed is higher than the appropriate temperature (40 ° C. or less) of the marine gas oil (second fuel). Although it is conceivable that the air cooling unit 23 is configured to apply cold air outside the engine room, in this case, it is necessary to dispose a blower duct or the like leading to the outside of the engine room, and the apparatus becomes large. There is a problem that it ends up. In view of the above points, it can be said that it is a judgment of those skilled in the art that it is difficult to dissipate the heat of the marine fuel cooler by air cooling.

  However, even if the inventor of the present application is in a relatively high temperature environment (around 45 ° C.) as in the engine room, the marine gas oil (second fuel) is supplied to the proper temperature in the fuel cooler 10 having the configuration of the present embodiment. It was found that it can be sufficiently cooled to (40 ° C. or lower). Therefore, the fuel cooler 10 of the present embodiment is configured to radiate heat to the air in the engine room. That is, the fuel cooler 10 of the present embodiment can efficiently transfer the heat of the second fuel to the air cooling unit 23 by the heat transfer member 21 and the Peltier element 22, and thus efficiently dissipate heat from the air cooling unit 23. be able to. Therefore, the fuel cooler 10 of this embodiment can exhibit sufficient cooling performance even in a relatively high temperature engine room. Thus, since the fuel cooler 10 is completed in the engine room (it is not necessary to apply air outside the engine room), the entire ship fuel supply system 1 can be configured in a compact and simple manner.

  Next, a characteristic configuration of the marine fuel supply system 1 of the present embodiment will be described.

  As described above, the first fuel is heated to a predetermined temperature (for example, around 130 ° C.) by the fuel heater 8 when supplied to the diesel engine 2. Therefore, the first fuel returned from the engine is sufficiently hot with respect to the room temperature (around 45 ° C.) of the engine room.

  Focusing on this point, in the marine fuel supply system 1 of the second embodiment, when the first fuel is used in the diesel engine 2, the fuel cooler is used when returning the high-temperature first fuel to the first fuel tank 7. 10 is configured to pass through and generate power.

  More specifically, it is as follows. That is, the marine fuel supply system 1 includes a first fuel return path (first fuel path) 36 that returns fuel from the diesel engine 2 to the first fuel tank 7 via the fuel cooler 10 (the fuel path 20 thereof). And a second fuel return path (second fuel path) 37 that returns to the second fuel tank 9 without using the fuel cooler 10. The return tank switching unit 12 is configured to be able to switch the supply destination of surplus fuel in the diesel engine 2 to one of the first fuel return path 36 and the second fuel return path 37. When the diesel engine 2 uses the first fuel, the return tank switching unit 12 returns the first fuel to the first fuel tank 7 using the first fuel return path 36. Further, when the second fuel is used in the diesel engine 2, the return tank switching unit 12 returns the second fuel to the second fuel tank 9 using the second fuel return path 37.

  With the above configuration, when the first fuel is used in the diesel engine 2, power can be generated by flowing the first fuel returned from the diesel engine 2 to the fuel cooler 10. That is, a temperature difference is generated between the cooling surface and the heat radiation surface of the Peltier element 22 by flowing the first fuel having a temperature sufficiently higher than the room temperature through the fuel passage 20 of the fuel cooler 10. By generating a temperature difference on both sides of the Peltier element 22 in this way, power can be generated by the Peltier element 22. When the first fuel is used in the diesel engine 2, the fuel cooler 10 is not used to cool the second fuel, and the second fuel flows into the fuel passage 20 of the fuel cooler 10. In this state, the first fuel can flow through the fuel cooler 10 as described above.

  In a general ship, since the steam generated by the exhaust gas economizer 35 is abundant in the ship, the fuel heater 8 that heats the first fuel using the steam has a surplus thermal energy. . In this embodiment, since the Peltier element 22 generates electricity by taking the heat amount of the first fuel once heated, it is not always efficient from the viewpoint of heating the first fuel. However, as described above, the fuel heater In FIG. 8, since heat energy is surplus, even if the heating efficiency of the first fuel is somewhat reduced, it does not matter. Rather, by using the configuration as described above, it is possible to recover the thermal energy of excess water vapor, which has been difficult to use in the past, as electrical energy by the Peltier element 22, so that the overall energy efficiency of the marine fuel supply system 1 is improved It can be made.

  As described above, the marine fuel supply system 1 of the present embodiment includes the first fuel tank 7, the second fuel tank 9, the fuel heater 8, the fuel cooler 10, and the supply fuel switching unit 6. Prepare. The first fuel tank 7 stores the first fuel. The 2nd fuel tank 9 stores the 2nd fuel whose viscosity in normal temperature is lower than a 1st fuel. The fuel heater 8 heats the first fuel and supplies it to the diesel engine 2. The fuel cooler 10 cools the second fuel and supplies it to the diesel engine 2. The supply fuel switching unit 6 performs switching so as to supply one of the first fuel from the fuel heater 8 and the second fuel from the fuel cooler 10 to the diesel engine 2. Further, the marine fuel supply system 1 includes a first fuel return path 36 that allows the first fuel to flow to the fuel cooler 10 when the first fuel is supplied to the diesel engine 2. The fuel cooler 10 is configured to cool the second fuel using the Peltier element 22, and when the first fuel passes, the Peltier element 22 generates power.

  As described above, by using the Peltier element 22 in the fuel cooler 10, the fuel cooler 10 can be simplified, noise can be reduced, and the apparatus can be downsized. The first fuel heated by the fuel heater 8 is in a sufficiently high temperature state with respect to the room temperature of the engine room. Therefore, by flowing this high temperature first fuel through the fuel cooler 10, electric power can be obtained at the Peltier element 22 of the fuel cooler 10.

  Further, the marine fuel supply system 1 of the present embodiment is configured as follows. That is, the first fuel return path 36 returns the first fuel remaining in the diesel engine 2 to the first fuel tank 7 via the fuel cooler 10 when the first fuel is supplied to the diesel engine 2.

  Thus, by generating electric power with the fuel cooler 10 using the 1st fuel returned from the diesel engine 2, surplus heat can be effectively collect | recovered as electric power. Moreover, it can avoid affecting the temperature of the 1st fuel supplied to the diesel engine 2 by generating electric power in the back | latter stage rather than the diesel engine 2. FIG.

  Further, the marine fuel supply system 1 of the present embodiment is configured as follows. That is, the fuel heater 8 is configured to heat the first fuel using the water vapor generated by the exhaust gas economizer 35 that generates the water vapor using the exhaust heat of the diesel engine 2.

  Generally, water vapor generated by an exhaust gas economizer is abundant in a ship. Therefore, by configuring as described above, the heat source of excess water vapor can be utilized and recovered as electric energy by the Peltier element 22. Thus, since heat energy that is difficult to use with water vapor can be easily converted into electric energy, energy can be effectively used.

  Next, a modification of the above embodiment will be described with reference to FIGS. In addition, about the structure which is common or similar to the said embodiment, the code | symbol same as the said embodiment is attached | subjected to drawing, and description is abbreviate | omitted.

  The fuel cooler 110 of this modification has a configuration in which a plurality of fins 40 are provided in the fuel passage 20. Each fin 40 is configured as a thin metal plate, and is disposed along the direction in which the fuel in the fuel passage 20 flows. Therefore, the fuel flow in the fuel passage 20 is not blocked by the fins 40. Further, the fins 40 are arranged so as to be orthogonal to the longitudinal direction of the heat transfer member 21, and are laminated with an appropriate interval in the longitudinal direction of the heat transfer member 21. Each heat transfer member 21 is disposed so as to penetrate each fin. The heat transfer member 21 and the fin are connected by an appropriate method such as welding.

  As described above, by providing the fin 40 in the fuel passage 20, the heat of the fuel (first fuel or second fuel) flowing in the fuel passage 20 can be more efficiently transmitted to the heat transfer member 21. it can.

  The preferred embodiments and modifications of the present invention have been described above, but the above configuration can be modified as follows, for example.

  Although the screw propeller 33 is driven by the diesel engine 2, the present invention is not limited to this, and the screw propeller 33 may be driven by an electric motor. In this case, the diesel engine 2 functions only as a drive source of the generator 34, supplies the electric power generated by the generator 34 to the electric motor, and drives the screw propeller 33.

  The marine fuel supply system 1 of the above embodiment is configured to selectively supply two types of fuel to the diesel engine 2, but may be configured to selectively supply three or more types of fuel. good.

  In the above-described embodiment, the heat transfer member 21 is a rod-shaped member. However, the heat transfer member 21 is not limited to this and may have an appropriate shape.

  In the above embodiment, the fuel passage 20 has a rectangular cross section. However, the shape is not limited to this, and the shape of the fuel passage 20 can be changed as appropriate. In addition, the shape and the like of the fuel cooler 10 are not limited to those illustrated, and can be changed as appropriate.

  The heat sink 30 and the blower fan 31 may be provided according to the cooling capacity of the fuel cooler 10, and are not essential. For example, if a sufficient cooling effect can be obtained with only the heat sink 30, the blower fan 31 may be omitted. Further, both the heat sink 30 and the blower fan 31 may be omitted. In this case, since heat is directly released from the heat dissipation surface of the Peltier element 22 to the surrounding air, the heat dissipation surface itself of the Peltier element 22 can be regarded as an air-cooled portion.

  The size and number of Peltier elements 22 to be attached to the ceiling plate 26 and the bottom plate 27 are not limited to those shown in the drawings. In addition to the ceiling plate 26 and the bottom plate 27, Peltier elements may be attached to the outer surfaces of the side plates 28 and 29.

DESCRIPTION OF SYMBOLS 1 Ship fuel supply system 2 Diesel engine 4 1st fuel supply path 5 2nd fuel supply path 8 Fuel heater 9 Fuel cooler 20 Fuel path 21 Heat transfer member 22 Peltier element 23 Air cooling part 36 1st fuel return path (1st fuel path) )

Claims (3)

A first fuel tank for storing a first fuel;
A second fuel tank for storing a second fuel having a viscosity at room temperature lower than that of the first fuel;
A fuel heater for heating and supplying the first fuel to the engine;
A fuel cooler that cools and supplies the second fuel to the engine;
A supply fuel switching section for switching to supply either the first fuel from the fuel heater or the second fuel from the fuel cooler to the engine;
A marine fuel supply system comprising:
A first fuel passage for flowing the first fuel to the fuel cooler when the first fuel is supplied to the engine;
The marine fuel supply system, wherein the fuel cooler is configured to cool the second fuel using a Peltier element, and when the first fuel passes, the Peltier element generates electric power. The marine fuel supply system according to claim 1,
When the first fuel is supplied to the engine, the first fuel passage returns the first fuel remaining in the engine to the first fuel tank via the fuel cooler. Ship fuel supply system. The marine fuel supply system according to claim 1 or 2,
The marine fuel supply system, wherein the fuel heater heats the first fuel using steam generated by an exhaust heat recovery device that generates steam using exhaust heat of the engine.

Images