JP2011226745A - Supply device and supply method of oil fuel for boiler burner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a supply device of an oil fuel that can utilize an oil fuel whose viscosity is higher than that of a heavy oil like asphalt.SOLUTION: The supply device includes a tank 2 that stores an oil fuel, a tank interior heater 4 that heats up the oil fuel, a pump 6 that feeds the oil fuel out of the tank 2, a fuel heating unit 8 that heats up the oil fuel to the temperature combusted by a boiler burner 7, an introduction pipe 10 that guides the oil fuel into the boiler burner 7, a tank return pipe 12 that branches from the introduction pipe 10 to return a part of the oil fuel to the tank 2, a burner return pipe 14 that merges the oil fuel not combusted by the boiler burner 7 via the tank return pipe 12, a vaporization suppressor 24 that suppresses the oil fuel from vaporizing, a first valve 16 that supplies the oil fuel to a merging portion 15, a second valve 18 that supplies the oil fuel to the boiler burner 7, and a third valve 20 that supplies the oil fuel not combusted by the boiler burner 7 to the merging portion 15, so that the flow of the oil fuel from a starting time to a normal operation time can be controlled.

Description

  The present invention relates to an oil fuel supply apparatus and supply method to a boiler burner, and in particular, oil fuel to a boiler burner from the start-up to normal operation of a boiler that uses oil fuel having a viscosity higher than that of heavy oil such as asphalt. The present invention relates to a supply device and a supply method.

  In recent years, in the oil refining process, for example, heavy stock (bright stock) is surplus due to the market trend for light oil such as naphtha and gasoline. For this reason, attempts have been made to use surplus heavy fractions as fuel for boiler plants. Among the heavy fractions, the SDA pitch, which is a residue of the solvent deasphalting process, tends to become excessive in particular, and therefore, there is a further demand for a method for utilizing the added value of the SDA pitch.

Since the SDA pitch is heavier and more viscous than the heavy oil asphalt that has been used as boiler fuel in the past, in order to ensure fluidity in the piping and equipment, and to spray combustion with the boiler burner, It is necessary to lower the viscosity by heating to a higher temperature than before.
However, when the SDA pitch exceeds, for example, 260 ° C. under atmospheric pressure, the vaporization rate increases, and the sulfidation corrosion of the steel due to the sulfur content contained in the SDA pitch may be accelerated.

Also, in a boiler using oil fuel, the oil fuel is circulated to warm up the system and gradually increase the combustion amount of the boiler burner during the period from the start of the boiler to the normal operation. In the process of moving from boiler startup to normal operation, high-temperature oil fuel that has passed through the heater is partly burned by the boiler burner, and partly merged with oil fuel that returns from the outlet of the jet fuel pump, and flows into the tank . In this case, the mixing and temperature after the joining of the oil fuels were not particularly considered.
For this reason, there is a possibility that the oil fuel after the merging may be vaporized in the pipe returning to the tank, or the high-temperature oil fuel may directly flow into the tank and be vaporized in the tank to increase the vent amount. In addition, when the mixing after merging is insufficient, local heating may occur in the tank due to the bias in the temperature of the oil fuel.

  Therefore, although not highly viscous like SDA pitch, Patent Document 1 proposes a method of supplying oil fuel having different viscosities such as C heavy oil and heavy oil to the boiler burner. In Patent Document 1, C heavy oil and heavy oil are heated so that the viscosities thereof are approximately the same, and C heavy oil and heavy oil having different temperatures are mixed and supplied by a mixer before being supplied to the burner. It has become.

JP 59-29918

  However, since Patent Document 1 does not target the SDA pitch as an oil fuel, the viscosity of the oil fuel is adjusted so that it can be burned by a boiler burner. Not considered.

  The present invention has been made in view of the above-described circumstances, and provides an oil fuel supply apparatus and supply method to a boiler burner that can utilize oil fuel having a viscosity higher than that of heavy oil such as asphalt while suppressing vaporization. The purpose is to provide.

  An oil fuel supply device to a boiler burner according to the present invention is an oil fuel supply device to a boiler burner that burns using oil fuel as a main fuel, a tank that stores oil fuel having a viscosity higher than that of heavy oil such as asphalt, A tank heating means provided in the tank for heating the oil fuel stored in the tank, a pump for sending the oil fuel heated by the tank heating means from the tank, and a pump sent by the pump A fuel heater for further heating the oil fuel to a temperature at which it is burned by the boiler burner; an introduction pipe for connecting the tank, the pump and the fuel heater to lead the oil fuel to the boiler burner; and a branch from the introduction pipe And a part of the oil fuel sent out by the pump is burned by a tank return pipe for returning the oil fuel to the tank and the boiler burner. A burner return pipe that joins the oil fuel to the tank return pipe; and a tank return pipe that is disposed in the tank return pipe and that maintains a constant pressure from the pump outlet. A first valve for supplying to the confluence of the fuel, and a flow rate of the oil fuel disposed in the introduction pipe and heated by the fuel heater is adjusted based on a load of the boiler burner, and the oil fuel is supplied to the boiler burner A second valve that is disposed in the burner return pipe and that supplies the oil fuel that has not been burned by the boiler burner to the junction, the first valve, the second valve, and the third valve The oil fuel supply control means for controlling the flow of the oil fuel from the start of the boiler to the normal operation so that the oil fuel is gradually supplied to the boiler burner. When, wherein the at between the said tank and the junction of the tank return pipe and a suppressing vaporization suppressing means vaporization of the oil fuel.

In the oil fuel supply device to the boiler burner, oil fuel having a viscosity higher than that of heavy oil such as asphalt is used as the main fuel, and the fuel is heated to a temperature at which the oil fuel is burned by the boiler burner. Fluidity and sprayability with boiler burner can be maintained. In addition, it suppresses the vaporization of the oil fuel between the junction of the tank return pipe and the tank while heating the oil fuel to a high temperature, thus suppressing the sulfur corrosion of the steel caused by the sulfur content in the oil fuel. Can do. Therefore, it is possible to utilize an oil fuel having a viscosity higher than that of heavy oil such as asphalt while suppressing vaporization.
In the present specification, heavy oil is a crude oil component that solidifies at room temperature (15 to 25 ° C.) like asphalt. Asphalt is obtained as a residue in the vacuum distillation of crude oil, and the softening point is usually 65 ° C. or lower.

In the apparatus for supplying oil fuel to the boiler burner, the vaporization suppression means includes an agitation means that is disposed downstream of the junction point between the tank return pipe and the burner return pipe and agitates the joined oil fuel. May be.
Thereby, since the oil fuels having different temperatures are agitated after joining, it is possible to easily equalize the temperature of the oil fuel and avoid the occurrence of a high temperature portion. Therefore, it can suppress that the oil fuel after joining is vaporized in the piping which returns to a tank, can suppress sulfide corrosion, and can maintain the temperature range which can use steel materials. Further, since hot oil fuel is prevented from flowing into the tank as it is, local heating in the tank is prevented.

Alternatively, the vaporization suppression means is disposed downstream of the joining point of the tank return pipe and the burner return pipe, and a temperature detection means for detecting the temperature of the oil fuel joined at the joining point; and the burner A flow rate detection means that is disposed in a return pipe and detects the flow rate of the oil fuel supplied by the third valve, and is supplied by the third valve based on detection results of the temperature detection means and the flow rate detection means. And third valve control means for controlling the flow rate of the oil fuel.
As a result, the flow rate of the oil fuel supplied by the third valve is controlled based on the detection results of the temperature detection means and the flow rate detection means, so that the temperature can be maintained below the temperature at which vaporization in the tank return pipe is mitigated. Therefore, it can suppress that the oil fuel after joining vaporizes in the piping which returns to a tank.

Alternatively, the vaporization suppression means is disposed downstream of the junction point between the tank return pipe and the burner return pipe, and detects an in-pipe pressure between the junction point and the tank. A pressure adjusting means provided on the tank inlet side of the tank return pipe for adjusting the pressure in the tank return pipe between the junction and the tank, and a pressure based on a detection result of the pipe pressure detector. You may have a pressure control part which controls an adjustment means.
As a result, the pressure in the tank return pipe between the junction and the tank is adjusted based on the detection result of the pipe pressure detector, so that the pressure can be kept below the pressure that reduces vaporization in the tank return pipe. Therefore, it can suppress that the oil fuel after joining vaporizes in the piping which returns to a tank.

An oil fuel supply method to a boiler burner according to the present invention is an oil fuel supply method to a boiler burner that burns using oil fuel as a main fuel in a tank that stores oil fuel having a viscosity higher than that of heavy oil such as asphalt. A heating step in the tank for heating the oil fuel, a step for sending the oil fuel heated in the heating step in the tank from the tank by a pump, and a temperature at which the oil fuel sent by the pump is burned by the boiler burner A fuel heating step for further heating, a tank return step for returning a part of the oil fuel sent out by the pump to the tank without going through the fuel heating step, and the oil fuel heated in the fuel heating step The oil fuel that has not been burned in the boiler burner from the pump in the tank return step. And oil fuel merging step of merging a portion of the oil fuel Back to serial tank,
A control process for controlling the flow of the oil fuel from the start of the boiler to a normal operation so that the oil fuel is gradually supplied to the boiler burner, and after the oil fuel merging process, until the oil fuel is returned to the tank A vaporization suppressing step for suppressing the vaporization of the joined oil fuel.

  In the method for supplying oil fuel to the boiler burner, oil fuel having a viscosity higher than that of heavy oil such as asphalt is used as the main fuel, and the oil fuel is heated to a temperature at which it is burned by the boiler burner. The sprayability can be maintained. In addition, while the oil fuel is heated to a high temperature, vaporization of the joined oil fuel is suppressed until the oil fuel is joined and returned to the tank, so the sulfur of the steel caused by the sulfur content in the oil fuel is suppressed. Corrosion can be suppressed. Therefore, it is possible to utilize an oil fuel having a viscosity higher than that of heavy oil such as asphalt while suppressing vaporization.

In the method for supplying oil fuel to the boiler burner, the joined oil fuel may be agitated in the vaporization suppression step after the oil fuel joining step.
Thereby, since the oil fuels having different temperatures are agitated after joining, it is possible to easily equalize the temperature of the oil fuel and avoid the occurrence of a high temperature portion. Therefore, it can suppress that the oil fuel after joining is vaporized in the piping which returns to a tank, can suppress sulfide corrosion, and can maintain the temperature range which can use steel materials. Further, since hot oil fuel is prevented from flowing into the tank as it is, local heating in the tank is prevented.

  In the present invention, oil fuel having a viscosity higher than that of heavy oil such as asphalt is used as the main fuel, and the oil fuel is heated to a temperature at which it is burned by the boiler burner, so that the fluidity of the oil fuel and the sprayability of the boiler burner are maintained. it can. In addition, while the oil fuel is heated to a high temperature, vaporization of the joined oil fuel is suppressed until the oil fuel is joined and returned to the tank, so the sulfur of the steel caused by the sulfur content in the oil fuel is suppressed. Corrosion can be suppressed. Therefore, it is possible to utilize an oil fuel having a viscosity higher than that of heavy oil such as asphalt while suppressing vaporization.

It is a schematic block diagram which shows the oil fuel supply apparatus to the boiler burner which concerns on Embodiment 1. FIG. It is a figure which shows an example of the oil fuel flow rate of each part until it transfers to normal driving | operation from the time of starting. It is a schematic block diagram which shows the oil fuel supply apparatus to the boiler burner which concerns on Embodiment 2. It is a schematic block diagram which shows the oil fuel supply apparatus to the boiler burner which concerns on Embodiment 3.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, but are merely illustrative examples. Not too much.

[Embodiment 1]
FIG. 1 is a schematic configuration diagram illustrating an oil fuel supply device to a boiler burner according to Embodiment 1 of the present invention.

  The oil fuel supply device 1 supplies oil fuel to a boiler burner 7 that burns as a main fuel. As shown in FIG. 1, the oil fuel supply device 1 mainly includes a tank 2, a pump 6, a fuel heater 8, and an introduction pipe 10. The tank return pipe 12, the burner return pipe 14, the first valve 16, the second valve 18, the third valve 20, the oil fuel supply control unit 22, and the vaporization suppression means (stirring means) 24. Composed.

  The tank 2 stores oil fuel having a viscosity higher than that of heavy oil such as asphalt. For example, SDA pitch, which is a residue of the solvent removal method, may be used as the “oil fuel having higher viscosity than heavy oil such as asphalt”. Since the SDA pitch has a higher viscosity than that of asphalt, it is preferably maintained at 200 ° C., for example, by the in-tank heating means 4 in consideration of fluidity in the pipe. The tank heating means 4 is provided in the tank 2 and heats the oil fuel stored in the tank 2.

The pump 6 sends out the oil fuel heated by the tank heating means 4 from the tank 2.
The fuel heater 8 further heats the oil fuel sent out by the pump 6 to a temperature at which it is burned by the boiler burner 7. When the oil fuel is SDA pitch, the temperature at which the boiler burner 7 burns is preferably set to 320 ° C., for example.

The introduction pipe 10 connects the tank 2, the pump 6, and the fuel heater 8, and guides the oil fuel to the boiler burner 7.
The tank return pipe 12 branches off from the introduction pipe 10 and returns a part of the oil fuel sent out by the pump 6 to the tank 2.
The burner return pipe 14 joins the tank fuel return pipe 12 with the oil fuel that has not been burned by the boiler burner 7.

The first valve 16 is disposed in the tank return pipe 12 and supplies oil fuel to a junction 15 between the tank return pipe 12 and the burner return pipe 14 with a constant pressure from the outlet of the pump 6.
The second valve 18 is disposed in the introduction pipe 10, adjusts the flow rate of the oil fuel heated by the fuel heater 8 based on the load of the boiler burner 7, and supplies the oil fuel to the boiler burner 7.
The third valve 20 is disposed in the burner return pipe 14 and supplies oil fuel that has not been burned by the boiler burner 7 to the junction 15.

As shown in FIG. 1, the oil fuel supply control unit 22 normally starts from the start of the boiler so that oil fuel is gradually supplied to the boiler burner 7 by the first valve 16, the second valve 18, and the third valve 20. Controls the flow of oil fuel until operation.
For example, as shown in FIG. 2, the oil fuel flow rate of each part (1) to (6) of the oil fuel supply device 1 is gradually changed by the first valve 16, the second valve 18, and the third valve 20. In FIG. 2, the fuel consumption at the time of boiler maximum load is set to 100%, and the oil fuel flow rate of each part is described.

Specifically, when the boiler is activated, the pump 6 is first warmed up. In this case, the oil fuel flow rate at the pump 6 outlet portion (1) and the oil fuel flow rate at the first valve 16 outlet portion (2) are 120%, and after the oil fuel is sent out from the pump 6, the whole amount returns to the tank. It returns to the tank 2 through the pipe 12.
Next, the piping of the oil fuel supply device 1 is warmed up. In this case, the oil fuel delivered from the pump 6 is supplied to each of the first valve 16 and the fuel heater 8. For example, the oil fuel flow rate at the outlet portion (2) of the first valve 16 may be 85%, and the oil fuel flow rate at the inlet portion (3) of the fuel heater 8 may be 35%.

After the pipe is warmed up, the boiler burner 7 is ignited. For example, when the combustion amount (4) of the boiler burner 7 is 15%, the oil fuel flow rate at the first valve 16 outlet (2) is 85%, and the oil fuel flow rate at the fuel heater 8 inlet (3) is 35%. The return (5) from the boiler burner 7 is 20%, and the return (6) of the oil fuel to the tank 2 is 105%.
After ignition of the boiler burner 7, the flow rate detector 28 adjusts so that oil fuel is gradually supplied to the boiler burner 7, thereby increasing the boiler load. At the time of boiler maximum load, the oil fuel flow rate of each part is 20% at the outlet part (2) of the first valve 16 and 100% at the inlet part (3) of the fuel heater 8, as shown in FIG. It will be 0% by the return from (5). Note that the boiler maximum load is when the combustion amount (4) of the boiler burner 7 is 100% and the boiler is in normal operation.

The vaporization suppression means suppresses the vaporization of oil fuel between the junction 15 of the tank return pipe 12 and the tank 2.
In the present embodiment, the vaporization suppression means may include an agitation means 24 that is disposed downstream of the junction 15 between the tank return pipe 12 and the burner return pipe 14 and agitates the joined oil fuel. The stirring unit 24 is not particularly limited as long as it can stir, but may be a line mixer, for example. Since the line mixer has a simple structure with good agitation, it does not require complicated control and can easily equalize the temperature of the oil fuel. Maintenance is also simple. Furthermore, since the line mixer can secure a large flow path for the oil fuel, there is no concern about clogging or sticking.

  As described above, since the oil fuels having different temperatures are agitated by the agitation unit 24 after being merged, the temperature of the oil fuel can be easily equalized to avoid the occurrence of a high temperature portion. Therefore, it can suppress that the oil fuel after joining vaporizes in the tank return pipe 12 which returns to the tank 2, can suppress sulfide corrosion, and can maintain the temperature range which can use steel materials. Further, since hot oil fuel is prevented from flowing into the tank 2 as it is, local heating in the tank 2 is prevented.

  In addition to the stirring means 24, the vaporization suppression means may include an on-site thermometer 26 and an on-site pressure gauge 27 as shown in FIG. The on-site thermometer 26 and the on-site pressure gauge 27 are disposed in the tank return pipe 12 and measure the temperature and pressure of the oil fuel after joining. By measuring the temperature and pressure of the oil fuel after joining, the state of the oil fuel stirred by the stirring means 24 can be confirmed.

  In the oil fuel supply apparatus 1 to the boiler burner having the above-described configuration, oil fuel having a viscosity higher than that of heavy oil such as asphalt is used as the main fuel, and the fuel heater 8 is heated to a temperature at which the oil fuel is burned by the boiler burner 7. Therefore, the fluidity of the oil fuel and the sprayability with the boiler burner 7 can be maintained. Further, since the oil fuel is suppressed from being vaporized between the junction 15 of the tank return pipe 12 and the tank 2 while the oil fuel is heated to a high temperature, sulfur corrosion of the steel material due to sulfur contained in the oil fuel is prevented. Can be suppressed. Therefore, it is possible to utilize an oil fuel having a viscosity higher than that of heavy oil such as asphalt while suppressing vaporization.

[Embodiment 2]
Next, the oil fuel supply apparatus to the boiler burner of Embodiment 2 is demonstrated. FIG. 3 is a schematic configuration diagram illustrating an oil fuel supply device to a boiler burner according to the second embodiment.
Since Embodiment 2 has the same configuration as that of the oil / fuel supply apparatus 1 described in Embodiment 1 except that the vaporization suppression means is different, detailed description thereof is omitted.

  In the present embodiment, the vaporization suppression means of the oil fuel supply device 1 includes a temperature detector 30, a flow rate detector 32, and a third valve control unit 35, as shown in FIG.

The temperature detector 30 is disposed downstream of the junction 15 between the tank return pipe 12 and the burner return pipe 14 and detects the temperature of the oil fuel that has joined at the junction 15.
The flow rate detector 32 is disposed in the burner return pipe 14 and detects the flow rate of the oil fuel supplied by the third valve 20.
The third valve control unit 35 controls the flow rate of the oil fuel supplied by the third valve 20 based on the detection results of the temperature detector 30 and the flow rate detector 32. Note that the third valve 20 preferably has a function of adjusting the flow rate of the oil fuel.

  Thus, since the flow rate of the oil fuel supplied by the third valve 20 is controlled based on the detection results of the temperature detector 30 and the flow rate detector 32, the temperature is less than the temperature at which the vaporization in the tank return pipe 12 is reduced. Can be maintained. Therefore, it can suppress that the oil fuel after joining vaporizes in the tank return pipe 12 which returns to the tank 2. FIG.

[Embodiment 3]
Next, an oil fuel supply apparatus to the boiler burner of Embodiment 3 will be described. FIG. 4 is a schematic configuration diagram illustrating an oil fuel supply device to a boiler burner according to the third embodiment.
Since Embodiment 3 has the same configuration as that of the oil fuel supply device 1 described in Embodiment 1 except that the vaporization suppression means is different, detailed description thereof is omitted.

  In the present embodiment, the vaporization suppression unit of the oil fuel supply apparatus 1 includes an in-pipe pressure detector 36, a pressure adjustment unit 38, and a pressure control unit 37, as shown in FIG.

The in-pipe pressure detector 36 is disposed on the downstream side of the junction 15 between the tank return pipe 12 and the burner return pipe 14 and detects the in-pipe pressure between the junction 15 and the tank 2.
The pressure control unit 37 controls the pressure adjusting means 38 based on the detection result of the in-pipe pressure detector 36.

  The pressure adjusting means 38 is provided on the tank 2 inlet side of the tank return pipe 12 and adjusts the pressure in the tank return pipe 12 between the junction 15 and the tank 2. The pressure adjusting means 38 is not particularly limited, and may be a pressure adjusting valve or an orifice installed in the tank return pipe 12.

When the boiler is started or when the oil fuel is circulated, the return from which the pressure from the outlet of the pump 6 is constant and the return from which the pressure from the boiler burner 7 changes merge at the junction 15. Therefore, the return flow rate of the tank return pipe 12 changes depending on the combustion state of the boiler burner 7. Therefore, vaporization is suppressed by maintaining a pressure at which the oil fuel in the tank return pipe 12 does not vaporize.
The pressure adjusting means 38 is preferably provided on the tank 2 inlet side of the tank return pipe 12 from the viewpoint of reducing the amount of oil fuel vaporization as much as possible.

  In this way, the pressure in the tank return pipe 12 between the junction 15 and the tank 2 is adjusted based on the detection result of the pipe pressure detector 36, so that the pressure that reduces vaporization in the tank return pipe 12 is reduced. The following can be maintained. Therefore, it can suppress that the oil fuel after joining vaporizes in the tank return pipe 12 which returns to the tank 2. FIG.

  As mentioned above, although embodiment of this invention was described in detail, it cannot be overemphasized that this invention is not limited to this, You may combine the structure demonstrated by embodiment arbitrarily in the range which does not deviate from the summary of this invention. .

DESCRIPTION OF SYMBOLS 1 Oil fuel supply apparatus 2 Tank 4 Tank heating means 6 Pump 7 Boiler burner 8 Fuel heater 10 Introducing pipe 12 Tank return pipe 14 Burner return pipe 15 Junction point 16 1st valve 18 2nd valve 20 3rd valve 22 Oil fuel supply Control unit 24 Stirring means (vaporization suppressing means)
30 Temperature detector 32 Flow rate detector 35 Third valve control unit 36 In-pipe pressure detector 37 Pressure control unit 38 Pressure adjusting means

Claims (6)

In an oil fuel supply device to a boiler burner that burns oil fuel as a main fuel,
A tank for storing oil fuel having a viscosity higher than that of heavy oil;
In-tank heating means for heating the oil fuel provided in the tank and stored in the tank;
A pump for sending out the oil fuel heated by the tank heating means from the tank;
A fuel heater that further heats the oil fuel delivered by the pump to a temperature at which it is burned by the boiler burner;
An introduction pipe for connecting the tank, the pump and the fuel heater, and leading the oil fuel to the boiler burner;
A tank return pipe branched from the introduction pipe and returning a part of the oil fuel sent out by the pump to the tank;
A burner return pipe that joins the oil fuel not burned in the boiler burner to the tank return pipe;
A first valve disposed in the tank return pipe and supplying the oil fuel to a junction of the tank return pipe and the burner return pipe with a constant pressure from the pump outlet;
A second valve disposed in the introduction pipe and configured to adjust a flow rate of the oil fuel heated by the fuel heater based on a load of the boiler burner, and to supply the oil fuel to the boiler burner;
A third valve disposed in the burner return pipe and supplying the oil fuel that has not been burned by the boiler burner to the junction;
Oil fuel that controls the flow of the oil fuel from the start of the boiler to the normal operation so that the oil fuel is gradually supplied to the boiler burner by the first valve, the second valve, and the third valve. Supply control means;
An oil fuel supply apparatus for a boiler burner, comprising: a vaporization suppression unit that suppresses vaporization of the oil fuel between the junction of the tank return pipe and the tank.   The said vaporization suppression means is arrange | positioned in the downstream of the said confluence | merging point of the said tank return pipe and the said burner return pipe, It has a stirring means which stirs the joined said oil fuel. Oil fuel supply system for boiler burners.   The vaporization suppression means is disposed downstream of the joining point of the tank return pipe and the burner return pipe, and a temperature detecting means for detecting the temperature of the oil fuel joined at the joining point; and the burner return pipe The flow rate detecting means for detecting the flow rate of the oil fuel supplied by the third valve, and the oil supplied by the third valve based on detection results of the temperature detection means and the flow rate detection means The oil fuel supply device for a boiler burner according to claim 1, further comprising third valve control means for controlling the flow rate of the fuel.   The vaporization suppression means is disposed downstream of the junction point between the tank return pipe and the burner return pipe, and detects an in-pipe pressure between the junction point and the tank, and the tank A pressure adjusting means provided on the tank inlet side of the return pipe for adjusting the pressure in the tank return pipe between the junction and the tank; and the pressure adjusting means is controlled based on the detection result of the in-pipe pressure detector. The oil fuel supply device to the boiler burner according to claim 1, further comprising: a pressure control unit that performs the operation. In a method for supplying oil fuel to a boiler burner that burns oil fuel as a main fuel,
An in-tank heating step for heating the oil fuel in a tank for storing oil fuel having a viscosity higher than that of heavy oil;
A step of pumping out the oil fuel heated in the tank heating step from the tank;
A fuel heating step of further heating the oil fuel delivered by the pump to a temperature at which it is burned by the boiler burner;
A tank return step for returning a part of the oil fuel sent out by the pump to the tank without going through the fuel heating step;
Guiding the oil fuel heated in the fuel heating step to the boiler burner;
An oil fuel joining step for joining the oil fuel not burned in the boiler burner to a part of the oil fuel returning from the pump to the tank in the tank return step;
A control step of controlling the flow of the oil fuel from the startup of the boiler to the normal operation so that the oil fuel is gradually supplied to the boiler burner;
A method for supplying oil fuel to a boiler burner, comprising: a vaporization suppression step for suppressing vaporization of the joined oil fuel before returning to the tank after the oil fuel joining step.   6. The method for supplying oil fuel to a boiler burner according to claim 5, wherein, in the vaporization suppression step, the joined oil fuel is stirred after the oil fuel joining step.

Images