JP5504394B2 - Fuel oil heating supply system using exhaust heat of diesel engine - Google Patents

Description

  In the present invention, when C heavy oil is used as a fuel oil for a diesel engine, the C heavy oil for heating to an appropriate viscosity is heated, and the fuel oil is heated and supplied using exhaust heat from the exhaust gas and high-temperature cooling water of the diesel engine. About the system.

  In small vessels, diesel engines are the mainstream propulsion engine, and C heavy oil is often used as fuel oil. In order to use C heavy oil as a fuel, it is necessary to supply it with an appropriate viscosity and an appropriate property. To maintain an appropriate viscosity and property, it is necessary to heat the C heavy oil and adjust it to an appropriate viscosity. For proper properties, it is necessary to reduce the viscosity by heating and clean it with a cleaner.

  In order to obtain good fuel injection and combustion, C heavy oil used in a diesel engine adopted in a small vessel is generally somewhat different depending on the engine, but generally has a viscosity at the time of fuel injection of 16 to 18 mm 2 / s (50 In order to obtain an appropriate viscosity, temperature control is required in the range of 112 ° C. to 108 ° C., and a steam boiler, a heat medium boiler, and an electric heater are used as the heat source. Yes.

  In large ships, steam is generally used to heat C heavy oil. However, in order to generate steam, auxiliary boilers, exhaust gas economizers, feed water pumps, cascade tanks, drain coolers, etc., and pipes for steam pipes and steam drain pipes are required, and a large space and cost are required. .

  Small boats have few crew members, and as a heat source for heating C heavy oil due to labor saving and space saving, many electric heater heating methods with larger generator capacity are adopted, and the amount of power required for heating is nautical power It occupies a big part in. Further, in this heating system, when the viscosity of C heavy oil is increased, more and more power is consumed by the electric heater, and there is a situation that cannot be handled by existing ships.

  Domestic ships operating in Japan are said to have about 4000 ships that use C heavy oil as fuel oil for diesel engines. Among them, the engine room is small and the total tonnage that employs the electric heater heating method is adopted. About 1,000 ships are operating from 499 tons to a gross tonnage of 749 tons, accounting for 30% of the total number of domestic ships.

Since the fuel oil temperature management in conventional small vessels is somewhat different depending on the type of engine and the manufacturer, it follows the “Guidelines on Fuel Oil and Lubricating Oil for Coastal Ship 4 Cycle Main Engine” as shown in FIGS. This will be explained using a schematic system.
In the figure, the vertical axis 1 shows the heating temperature of C heavy oil, the horizontal axis 2 shows the heating process, 65 ° C. in the fuel oil tank 3, 95 ° C. in the cleaner heater 4, 90 ° C. in the fuel oil regular tank 5, The fuel oil heater 6 is heated at 113 ° C. and 108 ° C. at the engine inlet 7 from the fuel oil tank 3 to the engine inlet 7 in sequence, and 8 and 9 indicate a temperature drop due to heat radiation in the pipe.

  A conventional system for heating and supplying fuel oil in a small ship will be described with reference to FIG. 2, which is a schematic system adopted in a 499-ton cargo ship (loading tonnage 1600 Kt, engine 1300 kW) which is a representative ship of an inner ship.

  The fuel oil heating supply system is composed of a fuel oil cleaning system and a fuel oil supply system. The fuel oil cleaning system will be described with reference to the drawings. A 7 Kw electric heater 11 is installed in the fuel oil tank 10, and C heavy oil heated to a set temperature of 65 ° C. is attached to the fuel oil purifier 12 through a pipe 14. The processing amount of the fuel oil purifier 12 supplied to the transfer pump 13 is adjusted to the processing capacity 1/2 to 1/3 by the valve 17, and the C heavy oil not processed is supplied to the fuel oil tank 10 through the pipe 16 as surplus C heavy oil. The C heavy oil to be processed is heated up to 95 ° C. from the transfer pump 13 by the 10 kW electric heater 19 of the cleaner heater 18 from the pipe 15 and supplied to the fuel oil cleaner 12 via the pipe 20 for cleaning. The C heavy oil is supplied to the fuel oil regular tank 22 via the pipe 21.

  The fuel oil regular tank 22 is provided with a 4 kW electric heater 23, C heavy oil is heated and kept at 90 ° C., and the supply amount is larger than the fuel oil consumption amount. Returned.

In the fuel oil supply system, the C heavy oil in the fuel oil service tank 22 is supplied with fuel consumption to the fuel oil supply pump 26 via the pipe 25, and further, the fuel oil heater 28 via the pipe 27 from the fuel oil supply pump 26. The 12 kW electric heater 29 is heated to 113 ° C. and connected to the diesel engine 31 via the pipe 30, and C heavy oil is supplied in a state heated to a temperature of 108 ° C. corresponding to the appropriate viscosity.

Excess C heavy oil obtained by subtracting the fuel consumption of the diesel engine 31 from the supply amount of the fuel oil supply pump 26 is supplied from the diesel engine 31 to the air separator 33 via the pipe 32.

In the air separator 33, the gas in the C heavy oil is separated, and the pipe 34 is connected to the pipe 25, and the total amount of the C heavy oil from the fuel oil regular tank 22 and the C heavy oil from the air separator 33 is This is a system leading to the fuel oil supply pump 26.

JP-A 09-58594 Ship fuel supply unit Patent application 2006-168094 Fuel oil supply device JP-A 07-317614 Fuel oil transfer device Registered Utility Model 3017366 Marine Fuel Supply Pump

Merchant Ship Engine Department Design Manual Piping System Japan Society of Marine Engineers Research Committee Report No. 87, December 1978 Guidelines for Fuel Oil and Lubricating Oil for Coastal Ship 4 Cycle Main Engines Japan Marine Manufacturers Association January 2009

As described above, the C heavy oil used in the diesel engine needs to be heated to have an appropriate viscosity and an appropriate property. There are energy saving systems that use steam economizers and heat medium oil economizers to heat C heavy oil. However, in small ships, it is very narrow and there are many to heat C heavy oil at the expense of energy saving. The electric heater heating method, in which the amount of electric power necessary for heating considering the space saving in which equipment and piping are reduced, is covered by the generator capacity driven by the diesel engine, has become the mainstream.

However, in the fuel oil situation where the viscosity of C heavy oil used is increasing, the heating temperature will be set higher to obtain the proper viscosity. In the heating system that requires a large capacity electric heater, the necessary power is required. In the situation where the amount is covered by the capacity of the diesel generator, it is necessary to increase the capacity of the generator.

In the example of the ship described above, 33 kW / h, which is 25%, is consumed for heating C heavy oil under the condition that the diesel generator is operated at a power consumption of 130 kW / h during the voyage. In the fuel oil situation where the viscosity is increased, the generator becomes larger, the fuel consumption becomes more and more, and there is a situation that the existing ship cannot cope with. Moreover, in an era when environmental issues are an important issue worldwide, a system that goes against energy conservation is not recognized as a good method. If a large number of devices are used, such as a system using a steam economizer or heat medium oil economizer, in order to adopt an energy-saving system, it is economically feasible if the cargo loading location must be sacrificed. do not do. Therefore, an energy saving system that can cope with heating of C heavy oil while keeping a space saving is an issue.

  The heat transfer oil flows inside the exhaust gas heat exchanger installed in the exhaust gas pipe of the diesel engine, is heated by the exhaust gas heat, and is heated by the exhaust gas through the heat transfer oil circulation pump to the primary side of the heat transfer oil heat heater. A first system which is supplied to the inlet by a pipe and is supplied from the primary outlet to the exhaust gas heat exchanger inlet through a pipe and circulates.

C heavy oil in the fuel oil regular tank is supplied to the fuel oil supply pump through a pipe, and is supplied to the secondary side inlet of the heat transfer oil heat exchanger through the pipe, and the primary side inside the heat transfer oil heat exchanger Heat exchanged with the heat transfer oil is heated and supplied from the secondary outlet to the primary inlet of the purifier fuel heater through the pipe, and C heavy oil is supplied from the primary outlet to the diesel engine through the pipe. The remaining surplus C heavy oil consumed in the diesel engine is connected to the air separator inlet by a pipe, and is supplied to the fuel oil supply pump inlet from the outlet to the fuel oil supply pump inlet, C heavy oil is supplied to the purifier transfer pump via a pipe, and is supplied to the secondary side inlet of the purifier fuel heater via the pipe, and the C heavy oil on the primary side inside the heat transfer medium heat exchanger The secondary C heavy oil heated and exchanged between the Is supplied to the fuel oil purifier, the cleaned, the second system of fuel oil cleaning system for supplying the fuel oil commonly used tank by a pipe.

Piping in parallel to the hot water heater equipped in the fuel oil tank and the hot water heater equipped in the fuel oil regular tank from the outlet of the high-temperature cooling water of the diesel engine, supplying hot water, from each of the hot water heaters 3rd system which connected piping to the high temperature cooling water cooler. A fuel oil heating and supplying system for heating fuel oil by exhaust heat of a diesel engine composed of a first system, a second system, and a third system.

In the exhaust gas heat exchanger, ribs are radially arranged on the inner peripheral wall of the engine exhaust pipe in the exhaust gas flow direction and welded to the exhaust pipe, and walls are attached to both ends of the tube that keeps a gap from the outer peripheral side of the exhaust pipe. Provided with exhaust pipe, both end walls, the inside surrounded by the tube is made of nectar, radially arranged ribs arranged at equal intervals around the circumference, in the exhaust gas flow direction, both ends Provide an oil nectar wall in contact with the wall, and for the oil nectar wall, provide heat medium oil inlet and heat medium oil outlet at both ends of the tube, and ribs with openings alternately on the entire circumference in a radial pattern The heat medium oil has a structure that forms a passage through which the heat medium oil flows from the heat medium oil inlet to the heat medium oil outlet in a state where the flow of the heat medium oil is alternately reversed. Heat transfer efficiency is increased by repeatedly turning the turbulent flow in the passage.

  The fuel oil supply pump has a capacity that is at least twice the fuel consumption of the diesel engine, so that when the C heavy oil on the secondary side is heated with the required amount of heat by the purifier fuel heater, the temperature of the primary C heavy oil is increased. Increase circulating fuel oil to prevent

In this fuel oil heating and supply system, the fuel oil consumption of the generator during the voyage does not require the power used by the conventional electric heater by using the exhaust heat of diesel engine for the heat treatment of C heavy oil Is greatly reduced. In addition, in the process of heating C heavy oil, C heavy oil in the fuel oil tank is provided with a hot water heater in the fuel oil tank, passed through the high-temperature cooling water of the diesel engine, heated with waste heat, and discharged from the fuel oil tank. Heating of C heavy oil can be performed by using the exhaust gas heat of the diesel engine, so that there are few facilities in the exhaust gas heat medium heater, there are few mechanical working parts, and the outer periphery of the exhaust pipe Because it is isolated from the internal gas by using the heat medium oil in the exhaust gas heat medium oil heater, the contact part of the high temperature exhaust gas selects the heat medium oil corresponding to the exhaust gas temperature, The life of the heat transfer oil is also extended. Even when the heat transfer oil circulation pump stops, it is safe, easy to maintain, and easy to operate.

The heat energy obtained from the diesel engine passes through the fuel oil heat exchanger through the fuel oil heat exchanger, heating the C heavy oil of the fuel oil and using it as the heat medium oil in order from the equipment that requires a high heating temperature. The equipment that requires a low heating temperature is provided with piping at the end, and the C heavy oil that has finished the heating work returns to the fuel oil supply pump and circulates. The piping is the heat transfer oil circuit described above. If the system is modularized on land, no heat transfer oil piping is required on the ship, and the conventional electric heater heating system and piping are almost the same fuel oil piping.

Compared to the method of heating the fuel oil by increasing the output of the generator with the conventional electric heater heating method, the output of the generator can be reduced and the consumption of fuel oil spent on the generator is also reduced. As a result, the electrical equipment is reduced and the equipment costs can be reduced. In addition, the apparatus is simple, and a space-saving, low-cost, energy-saving system can be provided.

It is a temperature control chart of the fuel oil in the conventional small ship. It is a schematic system diagram of the fuel oil heating supply system in the conventional small ship It is a temperature control chart of the fuel oil of the fuel oil heating supply system according to the embodiment of the present invention. 1 is a schematic system diagram of a fuel oil heating and supplying system according to an embodiment of the present invention. It is a center sectional view of the length of the exhaust gas heat exchanger concerning the embodiment of the present invention. 1 is a front view of an exhaust gas heat exchanger according to an embodiment of the present invention. It is a longitudinal section which shows arrangement of rib 79 of an exhaust gas heat exchanger concerning an embodiment of the present invention. It is a partial expanded view of the exhaust pipe which represented the flow of the heat transfer oil in the exhaust gas heat exchanger which concerns on embodiment of this invention.

The point of the fuel oil heating supply system of the present invention is that the C heavy oil, which is fuel oil, is heated to the set temperature of the fuel oil tank with high-temperature cooling water, and from the set temperature of the fuel oil tank to the enemy's positive viscosity. This is a system that uses the exhaust heat from the diesel engine to reach the viscosity that allows the C heavy oil to be cleaned and the viscosity that enables the C heavy oil to be cleaned.

Hereinafter, as an embodiment of the present invention, an example will be described with reference to FIGS.

The heating process will be described with reference to FIGS. 3 and 4. The vertical rod 1b indicates the heating temperature of C heavy oil, the horizontal axis 2b indicates the heating process, and the temperature setting standard is that the diesel engine 35 inlet temperature of 108 ° C. is heated from the reference point. When the process is calculated backwards, the temperature drop T0 of the purifier fuel heater 52 is 750 L / h, where the capacity of the fuel oil supply pump 47 is 2.5 times the fuel consumption, and the purifier throughput is the fuel consumption. 1.2 times 360L / h, heating temperature is calculated from fuel oil tank setting temperature 75 ° C to cleaner heating temperature 95 ° C, heat exchange efficiency is 0.9,
T0 = 360 × 20/750 / 0.9 = 10.7≈11
The temperature a3 of the inlet 53 of the purifier fuel oil heater 59 is the reference point temperature + the tube heat radiation temperature + T0, the reference point a5 is 108 ° C. and the tube heat radiation is 5 ° C., and T0 is 11 ° C. Is 129 ° C., and a 1 is the set temperature 90 ° C. of the fuel oil regular tank 57.

From the reference point to the fuel oil supply pump, in the process, the temperature a6 at the inlet of the air separator 58 is 103 ° C., which is higher than the set temperature of the fuel oil regular tank 57, and penetrates the air separator 58 into the fuel oil regular tank 57. If provided, the set temperature 90 ° C. of the fuel oil regular tank 57 can be maintained by the heat radiation of the air separator 58.

The C heavy oil has a set temperature 90 ° C. of the fuel oil regular tank 57 at a7, and a8 at the fuel supply pump is 85 ° C. in consideration of heat radiation from the pipe. a8 = a1. The capacity of the exhaust gas heat exchanger is only required to heat 750 L / h C heavy oil from 85 ° C. to 129 ° C. In the heat recovery of the exhaust gas in the daycel engine 35, the output in the secondary circuit of the fuel oil heat exchanger 41 is a heating capacity of 750 L / h C heavy oil from 85 ° C. to 129 ° C.

When the supply amount of the fuel oil supply pump 47 is 300 L / h, T0 is
T0 = 360 × 20/300 / 0.9 = 26.7 ° C.≈27 ° C.
The temperature of a2 is 145 ° C.
Since the exhaust gas temperature of a diesel engine has been in a tendency to decrease from 350 ° C. to 250 ° C. in recent years, it is more efficient to recover heat by lowering the C heavy oil heating temperature and increasing the capacity.

A schematic system diagram of a fuel oil heating and supplying system for a small vessel will be described with reference to FIG.
The fuel oil heating and supply system includes the following three systems. The first system is a circuit that heats the heat transfer oil with the heat of the exhaust gas, and the exhaust gas is exhausted in the middle of the exhaust pipe 36 through which the exhaust gas of the diesel engine 35 passes. The heat medium oil provided with the heat exchanger 37 and heated by the exhaust gas is supplied from the exhaust gas heat exchanger 37 to the heat medium oil circulation pump 39 through the pipe 38, and 1 of the fuel oil heat exchanger 41 is supplied through the pipe 40. It is a circuit that is connected to the secondary heat medium oil inlet 42 and supplies and circulates the heat medium oil through the pipe 44 from the primary heat medium oil outlet 43 to the exhaust gas heat exchanger 37.

  In the second system, the C heavy oil in the fuel oil service tank 57 is supplied to the fuel oil supply pump 47 through the pipe 46 and is connected to the secondary inlet 49 of the fuel oil heat exchanger 41 through the pipe 48. The supplied and heated C heavy oil passes through the pipe 51 from the secondary outlet 50 and is supplied to the primary inlet 53 of the purifier fuel heater 52, and is supplied from the primary outlet 54 to the diesel engine 35 through the pipe 55. A fuel oil supply circuit which is consumed and supplied to an air separator 58 provided through a fuel oil service tank 57 by a pipe 56 and connected to the pipe 46 by a pipe 59 to the fuel oil feed pump 47;

The C heavy oil in the fuel oil tank 60 is supplied to the cleaner transfer pump 62 through the pipe 61, and is supplied from the secondary inlet 64 of the cleaner fuel heater 52 through the pipe 63 to the primary C heavy oil. C heavy oil heated and exchanged between the two is sent from the secondary outlet 65 to the fuel oil purifier 67 through the pipe 66, and after cleaning, supplied to the fuel oil regular tank 60 through the pipe 68. Fuel oil cleaning circuit.

The third system is a circuit for heating the low temperature part, and is connected in parallel with the hot water heater 71 of the fuel oil tank 60 and the hot water heater 70 of the fuel oil regular tank 57 from the high temperature cooling water outlet 69 of the diesel engine 35. The hot water from the hot water heaters 70 and 71 is connected by a pipe 72 and is a circuit that is connected to a high-temperature cooling water cooler (not shown) by a pipe 73.

The high-temperature cooling water of the diesel engine 35 is controlled at an outlet temperature of about 80 ° C., and this waste heat is used to heat and keep the C heavy oil in the fuel oil regular tank 57 and the fuel oil clarifier tank 60. The set temperature of the clear tank 60 is a starting point for heating C heavy oil by exhaust gas, and the amount of heating of the purifier fuel heater 52 can be reduced because the capacity of the fuel oil heat exchanger can be reduced. The recovery device can be made compact from the exhaust gas heat. The use of the high-temperature cooling water of the diesel engine 35 is low in cost and easy to recover heat.

Exhaust gas heat exchanger 37 will be described with reference to the drawings. As shown in FIG. 5, ribs 96 are radially arranged on the inner surface of exhaust pipe 36 in the exhaust gas flow direction at equal intervals around the entire circumference.

As shown in FIGS. 5 and 6, a wall 76 is provided at the end of the tube 75 having a gap around the outer periphery of the exhaust pipe 36, and a wall 77 is provided at the opposite end, and the exhaust pipe 36 and the wall 76 are connected to the wall. The ribs 79 arranged radially at equal intervals are arranged in the exhaust gas flow direction 90 in the section 78 in which the inside surrounded by 77 and the tube cylinder 75 is made of nectar.

As shown in FIGS. 7 and 8, the rib 79 has an aa cross section, and, as shown, one end is in contact with the wall 76 and the rib 79 has an opening 91 on the wall 77 side. The ribs 79b having openings 91 on the wall 76 side are alternately arranged in the circumferential direction, and as shown in the cc cross section, an oil nectar wall 80 having both ends in contact with the wall 76 and the wall 77 is provided. The heat medium oil inlet 78 and the heat medium oil outlet 79 are provided at both ends of the tube cylinder 75, and the heat medium oil inlet 81 is used to heat the heat medium oil in a state where the flow of the heat medium oil is alternately reversed. A path 83 through which the heat medium oil flows is formed in the space up to the medium oil outlet 82. Heat transfer efficiency was increased by repeatedly reversing the heat transfer oil in the passage 83 to form a turbulent flow.

35 Diesel engine 36 Exhaust pipe 37 Exhaust gas heat exchanger 38, 40, 44 Heat medium pipe,
46, 48, 51, 55, 56, 59 C heavy oil 61, 63, 66, 68, C heavy oil 72, 73, high temperature cooling water pipe 47 fuel oil supply pump 58 air separator 57 heat medium oil regular tank 60 fuel oil tank 62 Cleaner transfer pump 52 Purifier fuel heater 67 Fuel oil purifiers 70 and 71, Hot water heater 75 Tube 76, 77 Wall 81 Heat transfer oil inlet 82 Heat transfer oil outlet 79, 79a, 79b Rib 80 Oil tight wall 83 Passage (heat transfer oil passage)

Claims (3)

The heat transfer oil flows inside the exhaust gas heat exchanger installed in the exhaust gas pipe of the diesel engine and is heated by the exhaust gas heat, and the heat medium oil heat exchanger primary side through the heat medium oil circulation pump by the pipe The first system that is supplied to the inlet by a pipe and supplied from the primary side outlet to the exhaust gas heat exchanger inlet through the pipe and circulates the C heavy oil in the fuel oil service tank is supplied to the fuel oil supply pump by the pipe. The heat medium oil heat exchanger is supplied to the secondary side inlet of the heat exchanger through the pipe, and heat is exchanged and heated with the heat medium oil on the primary side inside the heat medium oil heat exchanger. From the primary outlet, the C heavy oil is supplied to the diesel engine through the pipe, and the remaining surplus C heavy oil consumed in the diesel engine is supplied to the air through the pipe. The fuel oil supply pump is connected to the separator inlet and connected from the outlet through a pipe. And fuel oil supply system is supplied to the mouth, C heavy fuel oil Kiyoshi tank, via the tube supplied to the purifier transfer pump, the cleaner fuel heater secondary side by the tube from the cleaner transfer pump The secondary C heavy oil supplied to the inlet, heat-exchanged with the C heavy oil on the primary side and heated is supplied from the secondary outlet to the fuel oil purifier through a pipe, cleaned, and A fuel oil heating system comprising a second system of fuel oil cleaning system that supplies fuel oil service tanks, and uses exhaust heat to heat C heavy oil to a temperature that reaches the optimum viscosity that can be used by a diesel engine Supply system.   In the exhaust gas heat exchanger, ribs are radially arranged on the inner peripheral wall of the engine exhaust pipe in the flow direction of the exhaust gas and welded and fixed, and walls are provided at both ends of the pipe tube that keeps a gap from the outer peripheral side of the exhaust pipe. In the compartment surrounded by the exhaust pipe, both end walls, and the tube tube is made of nectar, radially arranged ribs arranged at equal intervals around the circumference are arranged in the flow direction of the exhaust gas. An oil honey wall that is in contact with the wall is provided, and for the oil honey wall, a heat medium oil inlet and a heat medium oil outlet are provided at both ends of the tube, and ribs having openings alternately are radially arranged around the circumference. The flow of the heat medium oil is configured so as to form a passage through which the heat medium oil flows from the heat medium oil inlet to the heat medium oil outlet in a state where the flow of the heat medium oil is alternately reversed. The exhaust of a diesel engine according to claim 1, wherein the heat transfer efficiency is increased by increasing the heat transfer efficiency by repeatedly inverting and reversing in the passage. Fuel oil heating supply system using.   In the fuel oil supply pump, the capacity of the primary C heavy oil is increased when the C heavy oil on the secondary side is heated with a necessary amount of heat by the purifier fuel heater by setting the capacity to more than twice the fuel consumption of the diesel engine. The fuel oil heating and supplying system using the exhaust heat of the diesel engine according to claim 1, wherein the circulating fuel oil is increased so as to prevent fuel from flowing.

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