CN108204321B

CN108204321B - Fuel oil transfer device

Info

Publication number: CN108204321B
Application number: CN201710223995.1A
Authority: CN
Inventors: 千千波孝泰
Original assignee: Hokushin Engineering Co ltd
Current assignee: Hokushin Engineering Co ltd
Priority date: 2016-12-16
Filing date: 2017-04-07
Publication date: 2020-05-19
Anticipated expiration: 2037-04-07
Also published as: JP6447618B2; TWI677621B; KR102013696B1; TW201823584A; CN108204321A; JP2018096348A; KR20180070426A

Abstract

The invention provides a fuel oil transfer device, which can manage the temperature of fuel oil in a fuel oil storage tank in a mode of not reducing the transfer efficiency of the fuel oil. When all or any one or more of the temperature and pressure of the fuel oil on the side sucked by the transfer pump (6) and the operation time of the transfer pump (6) satisfy predetermined conditions, the heated fuel oil is made to flow out toward the fuel oil storage tank (2) through the fuel oil suction side of the transfer pump (6) by the downflow pump (11) after the transfer pump (6) is forcibly stopped, whereby the fuel oil including the fuel oil to be circulated through the transfer pump (6) is mixed with the heated fuel oil, thereby improving the viscosity rise of the fuel oil.

Description

Fuel oil transfer device

Technical Field

The present invention relates to a method for heating fuel oil and a fuel oil transfer device using the same, and more particularly, to a method for preventing the fluidity of the transfer of fuel oil used in a main engine or an auxiliary engine such as a ship or a generator from being lowered, and a fuel oil transfer device using the same.

Background

As one of fuel oils used for boilers of ships, generators, and the like, C heavy oil is known. C heavy oil and other fuel oils having a relatively high viscosity are affected by temperature, and the viscosity is liable to change. When the viscosity is high, the flow resistance increases, and the transferability deteriorates.

In order to avoid an increase in the flow resistance, a treatment for raising the temperature of the fuel oil is used. The fuel oil has a reduced viscosity due to an increase in temperature, and the flow resistance is reduced.

For example, a fuel oil day tank is known which is provided with a fuel oil transfer device having a heating means for raising the temperature of fuel oil and includes a fuel oil precipitation tank for heating the fuel oil transferred from a fuel oil storage tank, and a fuel oil day tank for storing the fuel oil raised in temperature in the fuel oil precipitation tank and supplying the stored fuel oil to the fuel oil storage tank little by little (for example, patent document 1).

The fuel oil is transferred from the fuel oil storage tank to the fuel oil precipitation tank via the transfer pump, and the viscosity is reduced by performing a heating treatment in the fuel oil precipitation tank. The fuel oil heated in the fuel oil precipitation tank is purified and transferred to the fuel oil day tank, and a part of the fuel oil is discharged little by little from the fuel oil day tank to the fuel oil storage tank via the downflow pump.

Fuel oil is supplied from a fuel oil day tank to a fuel injection device of a main engine such as an internal combustion engine or other auxiliary machines used in a ship, a generator, or the like.

The fuel oil heated and returned to the fuel oil storage tank is locally mixed with the fuel oil stored in the storage tank. As a result, the fuel oil contained in the fuel oil storage tank is locally maintained at 36 to 40 ℃.

The temperature maintenance of the fuel oil is performed for the following reason. First, it is prevented that an increase in flow resistance occurring in the circulation path of the fuel oil exerts a high load on a pump or the like and adversely affects the pump or the like; second, the amount of fuel oil transferred from the fuel oil storage tank to the fuel oil precipitation tank is prevented from becoming unstable due to viscosity.

Conventionally, in order to prevent an increase in flow resistance due to an increase in viscosity, a structure is known in which the temperature of stored fuel oil is prevented from decreasing by heating the fuel oil in a fuel oil storage tank (for example, patent document 2).

For heating the fuel oil storage tank, for example, a configuration is used in which a pipe such as a heating pipe through which a heat medium such as steam can be circulated is provided in the fuel oil storage tank, or a configuration is used in which an electric heater is provided in a fuel oil transfer passage to the fuel oil storage tank.

The structure for heating the fuel oil storage tank requires a different facility from the heating mechanism for the fuel oil settling tank. Therefore, the structure becomes large, and the management cost increases. Further, the structure for heating the fuel oil storage tank is susceptible to the influence of the temperature of the seawater delivered to the fuel oil storage tank and the influence of the ambient outside air temperature, and heat loss may increase.

On the other hand, if the viscosity of the fuel oil increases, the load acting on the transfer pump changes, and this change may adversely affect the drive source of the transfer pump. The transfer pump is driven by a motor to which a drive current capable of obtaining a predetermined rotation speed and torque is applied. However, when the rotation speed is decreased due to the increase in viscosity, the drive current is increased to return the rotation speed to the original state. If the rotational speed is not recovered even when the drive current is increased, the drive current is further increased, which may cause an accident such as burning of the motor.

If a motor accident occurs, the fuel oil cannot be transferred, which causes a problem that the viscosity of the fuel oil in the fuel oil storage tank cannot be improved, the transfer efficiency of the fuel oil is lowered, or the temperature control cannot be performed.

Patent document

Patent document 1: japanese laid-open patent publication No. 2004-36594

Patent document 2: japanese laid-open patent publication No. 2012-159074

Disclosure of Invention

Technical problem to be solved by the invention

The technical problem of the present invention is to provide a heating method for fuel oil and a fuel oil transfer device using the heating method, wherein the temperature of the fuel oil in a fuel oil storage tank can be managed without causing cost increase and reducing the transfer efficiency of the fuel oil.

Means for solving the technical problem

In order to solve the above-described problems, the present invention is characterized in that, when all or one or more of the temperature and pressure of the fuel oil sucked by the transfer pump and the operation time of the transfer pump required until the fuel oil reaches a predetermined amount at a position where the fuel oil is stored for heating the fuel oil satisfy a predetermined condition, the transfer pump is forcibly stopped, and then the heated fuel oil is discharged to a fuel oil storage tank by a down-flow pump, whereby the fuel oil to be flowed through the transfer pump is mixed with the heated fuel oil, thereby improving the viscosity increase of the fuel oil.

Effects of the invention

According to the present invention, the heated fuel oil is mixed with the fuel oil in the fuel oil storage tank to heat the fuel oil in the fuel oil storage tank. As a result, a heating mechanism provided in the fuel oil storage tank is not required, and an increase in cost is suppressed.

When the viscosity of the fuel oil to be introduced and circulated by the transfer pump increases, the fuel oil to be shut off by forcibly stopping the transfer pump can be mixed with the heated fuel oil and also mixed with the fuel oil in the fuel oil storage tank. As a result, the temperature of both the fuel oil on the suction side of the transfer pump and the fuel oil in the fuel oil storage tank rises, and the viscosity thereof decreases, so that the transfer efficiency at the time of restarting the transfer pump can be improved.

Drawings

Fig. 1 is a schematic diagram showing the structure of a fuel oil transfer device for a heating method according to an embodiment of the present invention and the flow of fuel oil during heating of fuel oil.

Fig. 2 is a schematic view showing the flow of fuel oil at the time of fuel oil transfer performed by the fuel oil transfer device shown in fig. 1.

Fig. 3 is a block diagram for explaining a configuration of a control unit used in the fuel oil transfer device shown in fig. 1.

Fig. 4 is a line diagram for explaining the principle of the determination of the predetermined condition by the control unit shown in fig. 3.

Detailed Description

Hereinafter, embodiments for carrying out the present invention will be described.

Fig. 1 is a diagram showing a configuration of a fuel oil transfer apparatus 1 to which a method for heating fuel oil according to an embodiment of the present invention is applied.

The fuel oil transfer device 1 includes a fuel oil precipitation tank 3 and a fuel oil day tank 4 that communicate with a fuel oil storage tank 2.

The fuel oil precipitation tank 3 is a tank for heating fuel oil, and the fuel oil is heated to a temperature of 70 to 80 ℃ by a heater not shown, for example.

The fuel oil storage tank 2 and the fuel oil precipitation tank 3 are communicated through a transfer pipe 5, and a transfer pump 6, a temperature sensor 7 and a pressure sensor 8 are disposed midway therebetween.

The temperature sensor 7 measures, for example, the temperature on the fuel inlet side, i.e., the suction side, of the transfer pump 6.

The pressure sensor 8 is provided for monitoring a change in pressure of the fuel oil sucked into the transfer pump 6. The pressure change is used to determine a change in flow resistance corresponding to a change in viscosity of the fuel oil. In particular, when the viscosity becomes high and the flow resistance becomes large, the pressure on the inlet side of the transfer pump 6 tends to be vacuumed. Therefore, if a change in pressure that tends to cause vacuum is detected, heating for reducing the viscosity of the fuel oil is required.

The fuel oil precipitation tank 3 is provided with a level sensor 9 for detecting the level of the fuel oil sucked by the transfer pump 6.

The level sensor 9 is a sensor capable of detecting the liquid level when a predetermined amount of fuel oil is introduced into the fuel oil precipitation tank 3. The level sensor 9 is used to stop the driving of the transfer pump 6 when it is detected that a predetermined amount of fuel oil is introduced into the fuel oil precipitation tank 3.

The fuel oil day tank 4 is a tank for temporarily storing heated fuel oil after the fuel oil is purified, and supplying the fuel oil to an internal combustion engine or the like. The fuel oil storage tank 2 and the fuel oil day tank 4 are communicated through an intake pipe 10, and a downflow pump 11 is disposed midway therebetween. A part of the fuel oil stored in the fuel oil day tank 4 is flown down to the fuel oil storage tank 2 by the down-flow pump 11 to raise the temperature of the fuel oil in the fuel oil storage tank 2.

The reason why the down pump 11 is referred to in this case is that the fuel oil day tank 4 is assumed to be disposed at a higher position than the fuel oil storage tank 2. That is, the expression "fuel oil flows down" is used by being derived so that the fuel oil flows down from the upper fuel oil day tank 4 to the lower fuel oil storage tank 2.

In the configuration shown in fig. 1, a fuel oil precipitation tank 3 and a fuel oil day tank 4 are respectively connected to an intake pipe 10. Therefore, a valve 12 is provided in the flow path of the fuel oil outlet of each tank 3, 4 so that the flow path of the fuel oil from the two tanks 3, 4 or any one of the tanks to the fuel oil storage tank 2 can be set.

In the fuel oil transfer device 1 described above, the fuel oil sucked from the fuel oil storage tank 2 into the fuel oil precipitation tank 3 by the transfer pump 6 is heated to purify the heated fuel oil, and the fuel oil is introduced into the fuel oil day tank 4 in preparation for supplying the stored fuel oil to the internal combustion engine and the like.

Part of the fuel oil temporarily stored in the fuel oil precipitation tank 3 and/or the fuel oil day tank 4 is returned to the fuel oil storage tank 2 by the downflow pump 11. As a result, the fuel oil in the fuel oil storage tank 2 is locally heated to 36 to 40 ℃ by being mixed with the heated fuel oil.

In the present embodiment, as the operation time between the pumps, for example, the transfer pump 6 is selected to be operated for about 15 minutes and the downflow pump 11 is selected to be operated for about 45 minutes alternately. In this time, the operation time of the transfer pump 6 can correspond to, for example, the time until the level of the fuel oil is detected by the level sensor 9 in the fuel oil precipitation tank 3. That is, when the level sensor 9 detects the liquid level of the fuel oil during the operation time when the fuel oil is caused to flow at a flow rate based on the rated values such as the rotational speed and the drive current of the transfer pump 6, it can be determined that the viscosity of the fuel oil is not a flow resistance of the fuel oil, and when the operation time is exceeded, it can be determined that the viscosity of the fuel oil is high and the fluidity is poor. When the level sensor 9 detects that the fuel oil introduced into the fuel oil precipitation tank 3 reaches a predetermined amount, the operation of the transfer pump 6 is stopped to prevent the fuel oil from overflowing.

When there is no fuel oil consumption such as in parking, the operation time of the transfer pump 6 is short, and the time until the level sensor 9 is activated is, for example, about 6 minutes.

The paths through which the fuel oil is sucked from the fuel oil storage tank 2 toward the fuel oil precipitation tank 3 by the transfer pump 6 are denoted by reference numerals F1 to F5 in fig. 1. The path of the fuel oil flowing down from the fuel oil day tank 4 to the fuel oil storage tank 2 by the flow-down pump 11 is indicated by arrows F10 to F13 in fig. 2.

The configuration of the main part of the fuel oil transfer device 1 using such a configuration is disclosed in japanese patent laid-open No. 2012-17123, which was a prior application by the present applicant.

The fuel oil transfer device 1 of the present embodiment having the above-described configuration is characterized by a fuel oil heating method performed when the flow resistance of the fuel oil from the fuel oil storage tank 2 to the transfer pump 6 is increased. In this case, the heating means that the temperature of the fuel oil that has not been heated is increased by mixing the heated fuel oil with the fuel oil that has not been heated.

The fuel oil transfer device 1 is capable of selecting either a normal operation mode performed when the viscosity of the fuel oil is low and the flow resistance is low, or a heating operation mode performed when the viscosity is high and the flow resistance is increased. The normal operation mode is a mode in which the transfer pump 6 operated in accordance with the operation state of the level sensor 9 and the downflow pump 11 for supplying the fuel oil to the fuel oil storage tank 2 are alternately operated to circulate the fuel oil. The heating operation mode is a mode in which the transfer pump 6 is forcibly stopped, the fuel oil that has been shut off on the suction side of the transfer pump 6 is heated, and the fuel oil in the fuel oil storage tank 2 is also heated by the fuel oil returned to the fuel oil storage tank 2. It is preferable to perform the heating operation mode until the viscosity of the fuel oil intercepted at the transfer pump 6 side reaches a value that does not increase the flow resistance.

As the conditions for executing the heating operation mode, the parameters listed below are used.

That is, the parameters at least use the temperature and pressure of the fuel oil sucked by the transfer pump 6 and the operation time of the transfer pump 6. As described above, the operation time of the transfer pump 6 refers to the operation time until the level sensor 9 is activated and the time counted by the timer provided in the transfer pump 6 itself. If all or any one or more of these parameters match predetermined conditions requiring heating, the heating operation mode is executed.

Hereinafter, the configuration and operation for executing this operation mode will be described with reference to fig. 3.

The operation states of the transfer pump 6 and the downflow pump 11 are controlled by the control unit 20 shown in fig. 3.

The temperature sensor 7, the pressure sensor 8, and the level sensor 9 provided in the transport pipe 5 are connected to the input side of the control unit 20. The output side of the control unit 20 is connected to a drive unit of the transfer pump 6 and a drive unit of the downflow pump 11, respectively. Both the transfer pump 6 and the downflow pump 11 are of a type that can control the flow rate and the flow velocity by rotating control motors (components denoted by reference numerals Ml and M2 in fig. 1 and 2).

In fig. 3, reference numeral 15 is an operation panel for displaying, for example, the operation time of each of the

pumps

6 and 11, the flow rate of the fuel oil, and the like, and necessary conditions for inputting the fuel consumption amount and the return amount, and reference numeral 16 is a timer.

The timer 16 measures, for example, a required time from a time point when the transfer pump 6 starts operating to a time point when the level sensor 9 detects the liquid level. Therefore, when the operation time until the level sensor 9 detects the liquid level exceeds necessity while the transfer pump 6 is operating, it can be determined that the viscosity is high and the flow resistance is high. In other words, when the operation time of the transfer pump 6 exceeds the necessity, it can be determined that the viscosity of the fuel oil flowing through the transfer pump 6 is high and the flow resistance is large. The transfer pump 6 may be provided with a timer for measuring an operation time. In this case, when the transfer pump 6 is operated for an operation time set in its own timer or longer, it can be determined that the viscosity of the fuel oil is high and the flow resistance is high.

The monitoring target item for determining that the viscosity of the fuel oil is a predetermined condition for increasing the flow resistance may be a driving current value of a motor that is a driving source for transferring the pump 6.

The drive current value is determined to obtain a preset rotation speed and torque of the motor, but changes to return to the original state when the rotation speed and torque change, and particularly increases when the rotation speed and torque decrease. Accordingly, by monitoring the increase in the drive current value, it can be determined that the viscosity of the fuel oil has increased, and the operation mode can be switched.

The normal operation mode selected by the control unit 20 circulates the fuel oil while maintaining the temperature thereof at a value that does not increase the flow resistance when the viscosity of the fuel oil is the value. According to this operation mode, a state is maintained in which the decrease in the temperature of the fuel oil stored in the fuel oil storage tank 2 is suppressed and the increase in the viscosity is prevented.

The control unit 20 in the normal operation mode monitors the temperature and pressure of the fuel oil introduced into the transfer pump 6, the operation time of the transfer pump 6, and the change in the drive current value applied to the motor as the drive source of the transfer pump 6.

These monitoring target items are used as a change in viscosity of fuel oil, particularly as a predetermined condition for determining a viscosity increase, when 4 kinds of conditions are generated as described below, for example.

(1) The temperature at which the viscosity of the fuel oil increases and the flow resistance increases is not higher.

(2) The pressure change on the fuel oil introduction side of the transfer pump 6 is in a state of a vacuum tendency.

(3) The operation time of the transfer pump 6 until the level sensor 9 is operated is prolonged.

(4) The drive current value for the drive source of the transfer pump 6 increases.

The normal operation mode is executed without the viscosity of the fuel oil rising without satisfying these predetermined conditions.

When the normal operation mode is executed, a cycle of sucking fuel oil from the fuel oil storage tank 2 into the fuel oil precipitation tank 3 and a cycle of making a part of the fuel oil in the fuel oil precipitation tank 3 and/or the fuel oil day tank 4 flow down toward the fuel oil storage tank 2 are alternately repeated. Even during the circulation, the transfer pump 6 is stopped according to the operation of the level sensor 9. The operating state of each

pump

6, 11 when this operating mode is executed is displayed on the operation panel 15.

When the normal operation mode is executed while continuing the monitoring of the monitoring target item, if all, any one, or a plurality of the predetermined conditions derived from the monitoring target item match, the normal operation mode is switched to the heating operation mode.

In the heating operation mode, the transfer pump 6 is forcibly stopped, the downflow pump 11 is operated, and the heated fuel oil flows into the fuel oil storage tank 2. At this time, the heated fuel oil flows toward the fuel oil storage tank 2 while being mixed with the fuel oil stopped at the position via the fuel oil introduction side of the transfer pump 6. The fuel oil functions to remove clogging of the filter when flowing in a counter-flow manner with respect to the filter (in fig. 2, the member denoted by reference numeral FT), for example.

The control unit 20 can monitor the temperature and pressure of the monitoring target items directly by the sensors, but determines whether or not to execute the heating operation mode based on the state shown in fig. 4 with respect to the operation time of the transfer pump 6 until the liquid level is detected by the level sensor 9.

In fig. 4, the vertical axis represents the amount of fuel oil (the amount of operation of the level sensor 9), and the horizontal axis represents time.

In the figure, as the viscosity of the fuel oil increases, the time until the level sensor 9 is operated becomes longer when the transfer pump 6 is set to a fixed output.

Therefore, when the time (time indicated by reference symbol T in fig. 4) until the fuel oil having a low viscosity is introduced into the fuel oil precipitation tank 3 and the level sensor 9 is operated is longer than the time (time indicated by reference symbol T1 in fig. 4), it can be determined that the viscosity of the fuel oil is high. In the case where the transfer pump 6 itself includes a timer, the set time of the timer is compared with the actual operating time, and it can be determined that the viscosity of the fuel oil is high when the actual operating time is extended.

When the heating operation mode is selected when all or a part or a plurality of the predetermined conditions derived from the monitored target items match, the heated fuel oil is sent to the fuel oil storage tank 2. This allows the fuel oil to be mixed not only directly with the fuel oil in the fuel oil storage tank 2 but also with the fuel oil that has been shut off on the suction side of the transfer pump 6, thereby increasing the temperature of the fuel oil. As a result, since the fuel oil is heated in the oil passage before the fuel oil is sucked by the transfer pump 6, the viscosity of the fuel oil flowing into the transfer pump 6 can be surely reduced.

When the temperature, pressure, operation time of the transfer pump, and variation in drive current value in the motor of the transfer pump, which are items to be monitored, do not match the predetermined conditions under the condition that the viscosity increase is eliminated, the normal operation mode is returned.

According to the fuel oil transfer device 1 of the above embodiment, when the transfer pump 6 is forcibly stopped, the fuel oil heated in the fuel oil precipitation tank 3 is used, and not only the fuel oil sucked by the transfer pump 6 but also the fuel in the fuel oil storage tank 2 can be heated.

As a result, the fuel oil on the inlet side of the transfer pump 6 is heated while suppressing an increase in the driving load of the transfer pump 6, and the flow resistance is reduced, and almost forcibly reduced, so that the stop period can be shortened.

Industrial applicability

The present invention can heat both the fuel oil sucked by the transfer pump and the fuel oil in the fuel oil storage tank at the same time by forcibly stopping the transfer pump. Thus, unlike the case where the fuel oil of a viscosity having an increased flow resistance is transferred by the transfer pump, the fuel oil transfer device is highly practical in that the load on the transfer pump can be quickly reduced and the time required for restarting the transfer pump can be shortened only by driving the downflow pump.

Description of the reference numerals

1 fuel oil transfer device

2 fuel oil storage tank

3 fuel oil precipitation tank

4 fuel oil daily-use tank

5 transport pipe

6 transfer pump

7 temperature sensor

8 pressure sensor

16 time-meter

20 control part

Claims

1. A fuel oil transfer device is provided with:

a transfer pump which is provided in a transfer pipe for communicating a fuel oil storage tank with a fuel oil precipitation tank capable of heating fuel oil, and sucks the fuel oil in the fuel oil storage tank toward the fuel oil precipitation tank;

a downflow pump which is provided in a suction pipe connecting a fuel oil day tank for temporarily storing the heated fuel oil and the fuel oil storage tank and which gradually discharges the fuel oil from the fuel oil day tank;

a control unit for controlling the operation state of the transfer pump and the downflow pump,

the fuel oil transfer device is characterized in that,

a filter is provided in the transfer pipe at a position where the fuel oil discharged from the downflow pump flows backward with respect to the transfer pump when the transfer pump is stopped,

a temperature sensor for detecting at least the temperature of the fuel oil flowing from the fuel oil storage tank to the fuel oil precipitation tank, a pressure sensor for detecting the pressure of the fuel oil flowing into the transfer pump, and a timer for measuring the operation time of the transfer pump are connected to an input side of the control unit, and drive units of the transfer pump and the downflow pump are connected to an output side of the control unit, the control unit forcibly stops the transfer pump when it is determined that the viscosity of the fuel oil sucked by the transfer pump is high based on a result of comparing data from each sensor and the timer with a predetermined condition, and in order to eliminate a viscosity increase of the fuel oil flowing to the transfer pump, the heated fuel oil is mixed with the fuel oil stopped at a fuel oil suction side of the transfer pump by using the downflow pump, and flows out toward the fuel oil storage tank while flowing in a reverse flow in the filter.