Fuel supply device and control method for fuel supply device

Abstract

To stably supply a liquid fuel to a burner without vaporizing the liquid fuel in a pipeline.SOLUTION: A fuel supply device 100 for supplying a liquid fuel to a burner 210 comprises: a pressure vessel 20 holding the liquid fuel and a fuel gas into which the liquid fuel has vaporized; a first pipeline L1 for introducing the liquid fuel from the pressure vessel 20 to the burner 210; and a flow-rate regulation unit 40 for regulating a flow-rate of the liquid fuel supplied from the pressure vessel 20 to the burner 210 via the first pipeline L1 by regulating a pressure inside the pressure vessel 20.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a fuel supply device and a method for controlling the fuel supply device.

Background Art

[0002] Conventionally, a technique is known in which ammonia, which is a fuel that does not generate carbon dioxide during combustion, is burned together with a solid fuel such as coal to reduce the amount of carbon dioxide generated (see, for example, Patent Document 1). The combustion device disclosed in Patent Document 1 supplies a solid fuel and gaseous ammonia to a burner and co - burns the solid fuel and ammonia.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, when using gaseous ammonia as a fuel, there are the following problems. When vaporizing liquefied ammonia (in a pressurized state or a cryogenic state), which is a general form of ammonia circulation, to generate gaseous ammonia, a large amount of energy is required. Also, compared with other gaseous fuels (methane, propane, natural gas, etc.), the calorific value per unit volume of ammonia is low.

[0005] In addition, the heat loss (exhaust gas loss) increases due to the moisture generated by the combustion of ammonia. For this reason, the amount of fuel required to obtain the desired energy may increase, and the fuel storage and supply facilities may become larger. Also, when diverting existing fuel storage and supply facilities, the capacity (combustion amount) as a combustion facility may become smaller.

[0006] On the one hand, by using liquefied ammonia, it is possible to avoid the enlargement of fuel storage and supply facilities compared with gaseous ammonia. However, there are the following problems. Liquefied ammonia has a high vapor pressure at normal temperature (about 0.75 MpaG at 20°C). When used in a normal temperature environment, it may vaporize in the fuel system and cannot be stably supplied to combustion equipment such as burners. In particular, when a valve (throttle part) is installed for controlling pressure or flow rate, due to the differential pressure generated by the valve, the pressure on the downstream side of the valve may be below the vapor pressure of liquefied ammonia, resulting in vaporization (flash) and the possibility of unstable control.

[0007] In view of such circumstances, the present disclosure has been made, and an object thereof is to provide a fuel supply device and a control method thereof that can stably supply a liquid fuel to a burner without vaporizing the liquid fuel in a pipe.

Means for Solving the Problems

[0008] A fuel supply device according to an aspect of the present disclosure is a fuel supply device that supplies a liquid fuel to a burner, and includes a pressure vessel that holds the liquid fuel and fuel gas obtained by vaporizing the liquid fuel, a first pipe that guides the liquid fuel from the pressure vessel to the burner, and a flow rate adjustment unit that adjusts the internal pressure of the pressure vessel to adjust the flow rate of the liquid fuel supplied from the pressure vessel to the burner via the first pipe.

[0009] A control method of a fuel supply device according to an aspect of the present disclosure is a control method of a fuel supply device that supplies a liquid fuel to a burner. The fuel supply device includes a pressure vessel that holds the liquid fuel and fuel gas obtained by vaporizing the liquid fuel, and a first pipe that guides the liquid fuel from the pressure vessel to the burner. The control method includes a control step of adjusting the internal pressure of the pressure vessel to adjust the flow rate of the liquid fuel supplied from the pressure vessel to the burner via the first pipe.

Effects of the Invention

[0010] According to the present disclosure, it is possible to provide a fuel supply device and a control method thereof that can stably supply liquid fuel to a burner without vaporizing the liquid fuel in a pipe.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Modes for Carrying Out the Invention

[0012] 〔First Embodiment〕 Hereinafter, a boiler system according to a first embodiment of the present disclosure will be described with reference to the drawings. The boiler system of the present embodiment includes a fuel supply device 100 and a boiler 200 that burns liquid fuel supplied from the fuel supply device 100 to generate steam. The steam generated by the boiler 200 is used, for example, as power to rotate a steam turbine (not shown) connected to a generator (not shown).

[0013] The fuel supply device 100 of the present embodiment is a device that supplies liquid fuel to a burner 210 included in the boiler 200. The liquid fuel used in the present embodiment is a fuel (low-boiling fuel) that may vaporize at the environmental temperature where the fuel supply device 100 is installed, and is, for example, liquefied ammonia. As shown in FIG. 2, ammonia vaporizes at a pressure of about 1.02 MPaG or less, which is the vapor pressure, under normal temperature (30°C) conditions, and becomes a liquid by pressurizing it above the vapor pressure. The fuel supply device 100 maintains ammonia in a pressurized state exceeding the vapor pressure at the environmental temperature where the fuel supply device 100 is installed, and supplies the liquefied ammonia to the burner 210.

[0014] As the liquid fuel supplied from the fuel supply device 100 to the burner 210, other liquid fuels different from ammonia may be adopted. For example, other liquid fuels having a boiling point of 80°C or less at atmospheric pressure, such as aqueous ammonia solution, dimethyl ether, methanol, aqueous methanol solution, ethanol, aqueous ethanol solution, naphtha, or crude oil, may be adopted.

[0015] As shown in FIG. 1, the fuel supply device 100 includes a storage tank (storage unit) 10, a pressure vessel 20, a supply pump 30, a flow rate adjustment unit 40, a pressure sensor (pressure detection unit) 50, a control unit 90, a first pipe L1, a second pipe L2, and a third pipe L3. The first pipe L1 is a pipe that guides liquid fuel from the pressure vessel 20 to the burner 210. The second pipe L2 is a pipe that guides liquid fuel from the storage tank 10 to the pressure vessel 20. The third pipe L3 is a pipe that is connected to the upper part of the pressure vessel 20 and guides the vaporized fuel gas held in the pressure vessel 20 to the storage tank 10.

[0016] The storage tank 10 is a tank for storing liquid fuel. The storage tank 10 maintains the liquid fuel in a pressurized state at a pressure exceeding the saturated vapor pressure at the environmental temperature where the fuel supply device 100 is installed. Further, the storage tank 10 may maintain the liquid fuel so that the liquid fuel does not vaporize by maintaining the temperature below the liquefaction temperature (dew point).

[0017] The pressure vessel 20 is a vessel for holding liquid fuel and fuel gas into which the liquid fuel has vaporized. The lower layer side of the pressure vessel 20 is a liquid phase region A1 where liquid fuel is held. The upper layer side of the pressure vessel 20 is a gas phase region A2 where fuel gas is held.

[0018] The supply pump 30 is a device for supplying liquid fuel from the storage tank 10 to the pressure vessel 20. The supply pump 30 is disposed in the second pipe L2 that guides the liquid fuel from the storage tank 10 to the pressure vessel 20. The supply pump 30 is, for example, a positive displacement pump such as a screw pump. The electric motor that drives the supply pump 30 has its rotation speed controlled by a control signal transmitted from the control unit 90.

[0019] The flow rate adjustment unit 40 is a device for adjusting the pressure of the fuel gas held in the gas phase region A2 of the pressure vessel 20, thereby adjusting the pressure of the liquid fuel supplied from the pressure vessel 20 to the burner 210 via the first pipe L1. From the burner 210, liquid fuel having a flow rate corresponding to the supply pressure is introduced into the interior of the boiler 200. The flow rate adjustment unit 40 includes a heating unit 41 and a pressure regulating valve 42.

[0020] The heating unit 41 is a device for heating a part of the liquid fuel by heating the liquid fuel held in the liquid phase region A1 of the pressure vessel 20, thereby increasing the pressure inside the pressure vessel 20. The heating unit 41 heats the heater 41a so as to generate a heating amount corresponding to a control signal transmitted from the control unit 90.

[0021] The pressure regulating valve 42 is arranged in the third pipe L3 and is a valve that adjusts the internal pressure of the pressure vessel 20 by adjusting the discharge amount of the fuel gas held in the gas phase region A2 of the pressure vessel 20. The valve opening degree of the pressure regulating valve 42 is adjusted by a control signal transmitted from the control unit 90. The fuel gas that has passed through the pressure regulating valve 42 is guided through the third pipe L3 to the space on the upper layer side of the storage tank 10.

[0022] The pressure sensor 50 is arranged in the first pipe L1 and is a device that detects the pressure of the liquid fuel supplied to the burner 210. The pressure detected by the pressure sensor 50 is transmitted to the control unit 90.

[0023] The control unit 90 is a device that controls each part of the fuel supply device 100. The control unit 90 controls the flow rate adjustment unit 40 so that the pressure detected by the pressure sensor 50 becomes a predetermined target pressure. Based on the control signal transmitted from the control unit 90, the flow rate adjustment unit 40 can adjust the flow rate of the liquid fuel input from the burner 210 into the boiler 200 by adjusting the internal pressure of the pressure vessel 20 so that the pressure detected by the pressure sensor 50 becomes a predetermined target pressure.

[0024] Next, with reference to FIGS. 3 to 5, an adjustment method for adjusting the flow rate of the liquid fuel input from the burner 210 into the boiler 200 will be described. The flow rate of the liquid fuel is adjusted by the flow rate adjustment unit 40 based on the control signal transmitted from the control unit 90.

[0025] FIG. 3 is a graph showing the time change of the target pressure in the fuel supply device 100 according to the present embodiment. The target pressure Pt is the target value of the supply pressure of the liquid fuel passing through the first pipe L1 to the burner 210. The higher the target pressure Pt, the greater the flow rate of the liquid fuel supplied from the burner 210 to the boiler 200 per unit time through the first pipe L1, and the lower the target pressure Pt, the smaller the flow rate of the liquid fuel supplied from the burner 210 to the boiler 200 per unit time through the first pipe L1. The control unit 90 adjusts the flow rate of the liquid fuel supplied from the burner 210 to the boiler 200 by controlling the target pressure Pt.

[0026] In FIG. 3, the solid line indicates a state where the target pressure Pt is increased from the first target pressure Pt1 to the second target pressure Pt2 between time T1 and time T2. In FIG. 3, the dotted line indicates a state where the target pressure Pt is decreased from the second target pressure Pt2 to the first target pressure Pt1 between time T1 and time T2. When the control unit 90 increases the flow rate of the liquid fuel supplied to the burner 210, it sets the target pressure Pt shown by the solid line in FIG. 3. Further, when the control unit 90 decreases the flow rate of the liquid fuel supplied to the burner 210, it sets the target pressure Pt shown by the dotted line in FIG. 3.

[0027] The control unit 90 controls the heating amount of the heating unit 41 so that the pressure detected by the pressure sensor 50 matches the target pressure Pt. As shown by the solid line in FIG. 3, the target pressure Pt is constant at the first target pressure Pt1 from time T0 to time T1. Therefore, as shown by the solid line in FIG. 4, the heating amount by the heating unit 41 from time T0 to time T1 is constant at the first heating amount Q1. The control unit 90 controls the heating unit 41 to maintain the first heating amount Q1 from time T0 to time T1.

[0028] On the other hand, as shown by the solid line in FIG. 3, the target pressure Pt increases from the first target pressure Pt1 to the second target pressure Pt2 from time T1 to time T2. Therefore, as shown by the solid line in FIG. 4, the heating amount by the heating unit 41 from time T1 to time T2 increases from the first heating amount Q1 to the second heating amount Q2. The control unit 90 controls the heating unit 41 to increase from the first heating amount Q1 to the second heating amount Q2 from time T1 to time T2.

[0029] As shown by the dotted line in FIG. 3, the target pressure Pt is constant at the second target pressure Pt2 from time T0 to time T1. Therefore, as shown by the dotted line in FIG. 4, the heating amount by the heating unit 41 from time T0 to time T1 is constant at the second heating amount Q2. The control unit 90 controls the heating unit 41 to maintain the second heating amount Q2 from time T0 to time T1.

[0030] On the other hand, as shown by the dotted line in FIG. 3, from time T1 to time T2, the target pressure Pt decreases from the second target pressure Pt2 to the first target pressure Pt1. Therefore, as shown by the dotted line in FIG. 4, the heating amount by the heating unit 41 from time T1 to time T2 decreases from the second heating amount Q2 to the first heating amount Q1. The control unit 90 controls the heating unit 41 so as to decrease from the second heating amount Q2 to the first heating amount Q1 from time T1 to time T2.

[0031] As described above, the control unit 90 controls the heating amount of the heating unit 41 so that the pressure detected by the pressure sensor 50 matches the target pressure Pt. However, a response delay of the heating unit 41 or a response delay of the pressure change in the gas phase region A2 with respect to the change in the heating amount of the heating unit 41 occurs. Therefore, the control unit 90 adjusts the valve opening degree of the pressure adjustment valve 42 so that the pressure detected by the pressure sensor 50 matches the target pressure Pt.

[0032] As shown in FIG. 5, the valve opening degree of the pressure adjustment valve 42 is controlled to increase the opening degree from the first opening degree O1 when the pressure detected by the pressure sensor 50 exceeds the target pressure Pt, and to decrease the opening degree from the first opening degree O1 when the pressure detected by the pressure sensor 50 is lower than the target pressure Pt, with the first opening degree O1 as the center.

[0033] As shown by the solid line in FIG. 5, at time T1, the valve opening degree decreases significantly from the first opening degree O1 and then increases. This is because the increase in the pressure of the combustion gas in the gas phase region A2 lags behind the heating amount of the heating unit 41 that started increasing at time T1, and the valve opening degree is decreased to make the pressure detected by the pressure sensor 50 match the target pressure Pt.

[0034] Also, as shown by the dotted line in FIG. 5, at time T1, the valve opening degree increases significantly from the first opening degree O1 and then decreases. This is because the decrease in the pressure of the combustion gas in the gas phase region A2 lags behind the heating amount of the heating unit 41 that started decreasing at time T1, and the valve opening degree is increased to make the pressure detected by the pressure sensor 50 match the target pressure Pt.

[0035] Next, the time change of the heating amount and the time change of the valve opening degree in the fuel supply device according to the modified example of the present embodiment will be described with reference to FIGS. 6 and 7. Note that the time change of the target pressure Pt in the fuel supply device according to the modified example of the present embodiment is the same as that in FIG. 3.

[0036] As shown by the solid line in FIG. 4, in the present embodiment, when the target pressure Pt is increased at a constant gradient from time T1 to time T2, the heating amount Q is increased at a constant gradient from time T1 to time T2. On the other hand, in the modified example of the present embodiment, as shown by the solid line in FIG. 6, after the heating amount Q is increased at a constant gradient from time T1 to time T4, the increase rate of the heating amount Q is temporarily increased after time T4 has elapsed. Also, at time T2, a third heating amount Q3 that is larger than the second heating amount Q2 is set, and then it is decreased to the second heating amount Q2.

[0037] As shown by the solid line in FIG. 7, time T4 is the time when the valve opening degree of the pressure regulating valve 42 becomes the second opening degree O2. The control unit 90 controls to increase the valve opening degree of the pressure regulating valve 42 from the second opening degree O2 to the third opening degree O3 in response to the valve opening degree of the pressure regulating valve 42 becoming the second opening degree O2, and then maintains the first opening degree O1.

[0038] The reason why the control unit 90 increases the valve opening degree of the pressure regulating valve 42 in response to the valve opening degree of the pressure regulating valve 42 becoming the second opening degree O2 is that the second opening degree O2 is set as the lower limit value so that the valve opening degree of the pressure regulating valve 42 does not become excessively small. Also, the reason why the control unit 90 temporarily increases the increase rate of the heating amount Q after time T4 has elapsed is to correct the pressure detected by the pressure sensor 50 that has fallen below the target pressure Pt because the lower limit value of the valve opening degree of the pressure regulating valve 42 is set to the second opening degree O2.

[0039] Further, as shown by the dotted line in FIG. 4, in the present embodiment, when the target pressure Pt is decreased at a constant gradient from time T1 to time T2, the heating amount Q is decreased at a constant gradient from time T1 to time T2. On the other hand, in a modified example of the present embodiment, as shown by the dotted line in FIG. 6, after the heating amount Q is decreased at a constant gradient from time T1 to time T4, the rate of decrease of the heating amount Q is temporarily increased after time T4 has elapsed. Further, a fourth heating amount Q4 that is less than the first heating amount Q1 is set at time T2, and then the heating amount is decreased to the first heating amount Q1.

[0040] As shown by the dotted line in FIG. 7, time T4 is the time when the valve opening degree becomes the fourth opening degree O4. The control unit 90 controls the valve opening degree of the pressure regulating valve 42 to decrease from the fourth opening degree O4 to the fifth opening degree O5 in response to the valve opening degree of the pressure regulating valve 42 becoming the fourth opening degree O4, and then maintains the first opening degree O1.

[0041] The reason why the control unit 90 decreases the valve opening degree of the pressure regulating valve 42 in response to the valve opening degree of the pressure regulating valve 42 becoming the fourth opening degree O4 is that the fourth opening degree O4 is set as the upper limit value so that the valve opening degree of the pressure regulating valve 42 does not become excessively large. Further, the reason why the control unit 90 temporarily increases the rate of decrease of the heating amount Q after time T4 has elapsed is that since the pressure detected by the pressure sensor 50 exceeds the target pressure Pt due to the upper limit value of the valve opening degree of the pressure regulating valve 42 being set to the fourth opening degree O4, it is for correcting the exceeded pressure.

[0042] The actions and effects of the fuel supply device 100 of the present embodiment described above will be described. According to the fuel supply device 100 according to the present embodiment, the pressure vessel 20 holds the liquid fuel and the fuel gas vaporized from the liquid fuel, and the flow rate adjustment unit 40 adjusts the flow rate of the liquid fuel supplied from the burner 210 to the boiler 200 by adjusting the pressure inside the pressure vessel 20.

[0043] Since the second pipe L2 that guides the liquid fuel from the storage tank 10 to the pressure vessel 20 and the first pipe L1 that guides the liquid fuel from the pressure vessel 20 to the burner 210 are not provided with valves for reducing the pressure of the liquid fuel, the liquid fuel can be stably supplied to the burner 210 without vaporizing the liquid fuel in the second pipe L2 and the first pipe L1.

[0044] According to the fuel supply device 100 of the present embodiment, the pressure inside the pressure vessel 20 can be adjusted (increased) by heating the liquid fuel held in the pressure vessel 20 with the heating unit 41.

[0045] According to the fuel supply device 100 of the present embodiment, the pressure inside the pressure vessel 20 can be adjusted (decreased) by adjusting the discharge amount of the fuel gas held in the pressure vessel 20 with the pressure regulating valve 42 disposed in the third pipe L3 connected to the upper part of the pressure vessel 20.

[0046] According to the fuel supply device 100 of the present embodiment, the flow rate adjusting unit 40 adjusts the pressure of the liquid fuel detected by the pressure sensor 50 disposed in the first pipe L1 to be a predetermined target pressure Pt, so that the flow rate of the liquid fuel supplied from the burner 210 to the boiler 200 can be appropriately adjusted.

[0047] 〔Second Embodiment〕 Next, the fuel supply device 100A according to the second embodiment of the present disclosure will be described. This embodiment is a modification of the first embodiment and is the same as the first embodiment except as specifically described below, and the description below will be omitted.

[0048] As shown in FIG. 8, the fuel supply device 100A of the present embodiment is different from the fuel supply device 100 of the first embodiment in that it includes a flow rate detection unit 60. The flow rate detection unit 60 is a device that is disposed in the first pipe L1 and detects the flow rate of the liquid fuel flowing through the first pipe L1. The flow rate detected by the flow rate detection unit 60 is transmitted to the control unit 90.

[0049] In this embodiment, the control unit 90 controls the supply pump 30 so that the flow rate detected by the flow rate detection unit 60 becomes a predetermined target flow rate. The supply pump 30 is, for example, a positive displacement pump such as a screw pump. The control unit 90 adjusts the flow rate of the liquid fuel discharged from the supply pump 30 by controlling the rotation speed of the electric motor that rotationally drives the supply pump.

[0050] According to the fuel supply device 100A of this embodiment, the flow rate of the liquid fuel discharged from the supply pump 30 is controlled to be equal to the flow rate of the liquid fuel detected by the flow rate detection unit 60 disposed in the first pipe L1. Thereby, an amount of liquid fuel necessary for adjusting the pressure inside the pressure vessel 20 is held in the pressure vessel 20, and the liquid fuel at a predetermined target flow rate can be supplied from the burner 210 to the boiler 200.

[0051] 〔Third Embodiment〕 Next, the fuel supply device 100B according to the third embodiment of the present disclosure will be described. This embodiment is a modification of the first embodiment, and is the same as the first embodiment except as particularly described below, and the description below will be omitted.

[0052] As shown in FIG. 9, the fuel supply device 100B of this embodiment is different from the fuel supply device 100 of the first embodiment in that it includes a liquid fuel detection unit 70. The liquid fuel detection unit 70 is a sensor that detects the amount of liquid fuel held in the pressure vessel 20. The liquid fuel detection unit 70 detects the amount of liquid fuel held in the pressure vessel 20, for example, by detecting the height of the liquid level of the liquid fuel held in the pressure vessel 20. The amount of liquid fuel detected by the liquid fuel detection unit 70 is transmitted to the control unit 90.

[0053] In this embodiment, the control unit 90 controls the supply pump 30 so that the amount of the liquid fuel detected by the liquid fuel detection unit 70 becomes a predetermined target amount (the amount necessary for adjusting the pressure inside the pressure vessel 20). The supply pump 30 is, for example, a positive displacement pump such as a screw pump. The control unit 90 adjusts the amount of the liquid fuel discharged from the supply pump 30 by controlling the rotation speed of the electric motor that rotationally drives the supply pump 30.

[0054] According to the fuel supply device 100B of this embodiment, the supply pump 30 is controlled so that the amount of the liquid fuel held in the pressure vessel 20 detected by the liquid fuel detection unit 70 becomes a predetermined target amount. As a result, the amount of the liquid fuel necessary for adjusting the pressure inside the pressure vessel 20 is held in the pressure vessel 20, and the liquid fuel with a predetermined target flow rate can be supplied from the burner 210 to the boiler 200.

[0055] 〔Fourth Embodiment〕 Next, a fuel supply device 100C according to the fourth embodiment of the present disclosure will be described. This embodiment is a modification of the first embodiment, and is the same as the first embodiment except as specifically described below, and the description below will be omitted.

[0056] In the fuel supply device 100 of the first embodiment, the flow rate adjustment unit 40 adjusted the internal pressure of the pressure vessel 20 by adjusting the discharge amount of the fuel gas held above the pressure vessel 20. On the other hand, the flow rate adjustment unit 40C of this embodiment adjusts the pressure of the fuel gas held in the storage tank (pressure vessel) 10.

[0057] As shown in FIG. 10, the flow rate adjustment unit 40C of this embodiment is a device that adjusts the flow rate of the liquid fuel supplied from the burner 210 to the boiler 200 via the first pipe L1 by adjusting the discharge amount of the fuel gas held in the gas phase region B2 of the storage tank 10 to adjust the internal pressure of the storage tank 10. The flow rate adjustment unit 40C includes a heating unit 41C and a pressure adjustment valve 42C.

[0058] The heating unit 41C is a device that vaporizes a part of the liquid fuel by heating the liquid fuel held in the liquid phase region B1 of the storage tank 10, thereby increasing the pressure inside the storage tank 10. The heating unit 41C heats the heater 41Ca so as to generate a heating amount according to a control signal transmitted from the control unit 90.

[0059] The pressure regulating valve 42C is a valve that is disposed in the fourth pipe L4 and adjusts the discharge amount of the fuel gas held in the gas phase region B2 of the storage tank 10. The valve opening degree of the pressure regulating valve 42C is adjusted by a control signal transmitted from the control unit 90. The fuel gas that has passed through the pressure regulating valve 42C is guided to a liquid fuel recovery facility (for example, an ammonia recovery facility) (not shown) via the fourth pipe L4.

[0060] The control unit 90 controls the flow rate adjustment unit 40C so that the pressure detected by the pressure sensor 50 becomes a predetermined target pressure. Based on a control signal transmitted from the control unit 90, the flow rate adjustment unit 40C adjusts the pressure of the fuel gas held in the gas phase region B2 of the storage tank 10 so that the pressure detected by the pressure sensor 50 becomes a predetermined target pressure.

[0061] According to the fuel supply device 100C of the present embodiment, the flow rate of the liquid fuel supplied to the burner 210 can be adjusted using the storage tank 10 for storing the liquid fuel. That is, the storage tank 10 can have both a function of storing the liquid fuel and a function of adjusting the flow rate of the liquid fuel supplied to the burner 210.

[0062] 〔Fifth Embodiment〕 Next, a fuel supply device 100D according to the fifth embodiment of the present disclosure will be described. This embodiment is a modification of the first embodiment, and is the same as the first embodiment except as specifically described below, and the description thereof will be omitted below.

[0063] As shown in FIG. 11, the fuel supply device 100D of the present embodiment does not include a heating unit 41 in the pressure vessel 20C. Further, the pressure vessel 20C is provided with a sensor 70C for detecting the volume of the gas phase region A2. The volume of the gas phase region A2 may be calculated by detecting the liquid level height of the liquid phase region A1 of the pressure vessel 20C.

[0064] A discharge valve 42D that functions as a flow rate adjustment unit 40D is arranged in the third pipe L3, and discharges the fuel gas held in the gas phase region A2 of the pressure vessel 20C to the gas phase region B2 of the storage tank 10. The fuel gas that has passed through the discharge valve 42D may be led to a liquid fuel recovery facility (not shown). The valve opening degree of the discharge valve 42D is adjusted by a control signal transmitted from the control unit 90. The control unit 90 controls the discharge valve 42D so that the volume of the gas phase region A2 detected by the sensor 70C becomes smaller than a predetermined value.

[0065] According to the fuel supply device 100D of the present embodiment, a gas phase region A2 is provided in the pressure vessel 20C, and fuel gas is discharged from the gas phase region A2 through the discharge valve 42D. Thereby, even if the pressure vessel 20C is supplied with liquid fuel in a state where fuel gas is mixed therein, the fuel gas is separated in the pressure vessel 20C so that the fuel gas is not supplied to the burner 210, and it is possible to avoid the combustion in the burner 210 from becoming unstable.

[0066] 〔Sixth Embodiment〕 Next, the fuel supply device 100E according to the sixth embodiment of the present disclosure will be described. This embodiment is a modification of the first embodiment, and is the same as the first embodiment except as specifically described below, and the description thereof will be omitted below.

[0067] As shown in FIG. 12, the fuel supply device 100E of the present embodiment has a heater 41b and a heater 41c whose heat generation amounts that can change per unit time are different as the flow rate adjustment unit 40, and has a pressure adjustment valve 42 and a pressure adjustment valve 43 whose valve capacities (relationship between valve opening degree and CV value) are different.

[0068] The heater 41c has a larger heat quantity changeable per unit time than the heater 41b, that is, it has a high time responsiveness, and is constituted by, for example, an electric heater. The heater 41b has a smaller heat quantity changeable per unit time than the heater 41c, that is, it has a low time responsiveness, and is constituted by, for example, a steam heater. On the other hand, the absolute value of the heat quantity of the heater 41b is larger than the absolute value of the heat quantity of the heater 41c.

[0069] When the difference between the pressure detected by the pressure sensor 50 and the target pressure Pt is small, the control unit 90 controls to heat using the heater 41c with high responsiveness. When the difference between the pressure detected by the pressure sensor 50 and the target pressure Pt is large, the control unit 90 controls to heat using both the heater 41b and the heater 41c.

[0070] According to the fuel supply device 100D of the present embodiment, by using a plurality of heaters 41b and 41c having different heat quantities changeable per unit time, when the heat quantity to be changed is small, the heater 41c having a large heat quantity changeable per unit time can be used to enhance the responsiveness. Further, when the heat quantity to be changed is large, the heater 41b having a small heat quantity changeable per unit time but a large absolute value of the heat quantity can be used in combination, whereby the heat quantity can be suitably controlled.

[0071] The pressure regulating valve 43 has a smaller valve capacity than the pressure regulating valve 42, but fine control is possible (control accuracy is high). On the other hand, the pressure regulating valve 42 has a larger valve capacity than the pressure regulating valve 43, but the control accuracy is low.

[0072] When the difference between the pressure detected by the pressure sensor 50 and the target pressure Pt is small, the control unit 90 controls to adjust the flow rate using the pressure regulating valve 43 with high control accuracy. When the difference between the pressure detected by the pressure sensor 50 and the target pressure Pt is large, the control unit 90 controls to adjust the flow rate using both the pressure regulating valve 42 and the pressure regulating valve 43.

[0073] According to the fuel supply device 100D of the present embodiment, by using a plurality of pressure regulating valves 42 and 43 with different valve capacities, when the flow rate to be changed is small, the control accuracy can be improved by using the pressure regulating valve 43 with a small valve capacity. Further, when the flow rate to be changed is large, the flow rate can be appropriately controlled by using the pressure regulating valve 42 with a large valve capacity in combination.

[0074] The fuel supply device described in the embodiment described above can be understood as follows, for example. The fuel supply device (100) according to the present disclosure is a fuel supply device (100) that supplies liquid fuel to a burner (210), and includes a pressure vessel (20) that holds the liquid fuel and fuel gas obtained by vaporizing the liquid fuel, a first pipe (L1) that guides the liquid fuel from the pressure vessel to the burner, and a flow rate adjustment unit (40) that adjusts the pressure inside the pressure vessel to adjust the flow rate of the liquid fuel supplied from the pressure vessel to the burner via the first pipe.

[0075] According to the fuel supply device according to the present disclosure, the pressure vessel holds the liquid fuel and fuel gas obtained by vaporizing the liquid fuel, and the flow rate adjustment unit adjusts the pressure inside the pressure vessel to adjust the flow rate of the liquid fuel supplied from the pressure vessel to the burner. Since no valve for reducing the pressure of the liquid fuel is provided in the first pipe that guides the liquid fuel from the pressure vessel to the burner, the liquid fuel can be stably supplied to the burner without vaporizing the liquid fuel in the first pipe.

[0076] In the fuel supply device according to the present disclosure, a configuration may be adopted that includes a storage unit (10) for storing the liquid fuel, a second pipe (L2) for guiding the liquid fuel from the storage unit to the pressure vessel, and a supply pump (30) that is disposed in the second pipe and supplies the liquid fuel from the storage unit to the pressure vessel. According to the fuel supply device of this configuration, the liquid fuel stored in the storage unit can be supplied from the storage unit to the pressure vessel via the second pipe by the supply pump.

[0077] In the fuel supply device according to the present disclosure, the flow rate adjustment unit may be configured to include a heating unit (41) that vaporizes the liquid fuel by heating the liquid fuel to increase the pressure inside the pressure vessel. According to the fuel supply device of this configuration, the pressure inside the pressure vessel can be adjusted by heating the liquid fuel held in the pressure vessel with the heating unit.

[0078] In the fuel supply device according to the above configuration, the flow rate adjustment unit may be configured to include a plurality of the heating units having different heat generation amounts that can vary per unit time. According to the fuel supply device of this aspect, by using a plurality of heating units having different heat generation amounts that can vary per unit time, when the heat generation amount to be increased is small, a heating unit with a large heat generation amount that can vary per unit time can be used to enhance the responsiveness. Also, when the heat generation amount to be increased is large, a heating unit with a small heat generation amount that can vary per unit time but a large absolute value of the heat generation amount can be used to appropriately increase the heat generation amount.

[0079] In the fuel supply device according to the present disclosure, the flow rate adjustment unit includes a third pipe (L3) that is connected to the upper part of the pressure vessel and guides the fuel gas held in the pressure vessel to the outside, and the flow rate adjustment unit may be configured to include a pressure adjustment valve (42) that is disposed in the third pipe and adjusts the pressure inside the pressure vessel. According to the fuel supply device of this configuration, the pressure inside the pressure vessel can be adjusted by the pressure adjustment valve disposed in the third pipe connected to the upper part of the pressure vessel.

[0080] In the fuel supply device according to the above configuration, the flow rate adjustment unit may be configured to include a plurality of the pressure adjustment valves having different valve capacities. According to the fuel supply device of this aspect, by using a plurality of pressure adjustment valves having different valve capacities, when the flow rate to be increased is small, a pressure adjustment valve with a small valve capacity but high control accuracy can be used to enhance the control accuracy. Also, when the flow rate to be increased is large, a pressure adjustment valve with a large valve capacity can be used to appropriately increase the flow rate.

[0081] In the fuel supply device according to the present disclosure, a pressure detection unit (50) may be provided that is disposed in the first pipe and detects the pressure of the liquid fuel flowing through the first pipe, and the flow rate adjustment unit may be configured to adjust the pressure inside the pressure vessel so that the pressure detected by the pressure detection unit becomes a predetermined target pressure. According to the fuel supply device of this configuration, the flow rate adjustment unit adjusts the pressure of the liquid fuel detected by the pressure detection unit disposed in the first pipe to a predetermined target pressure, thereby appropriately adjusting the flow rate of the liquid fuel supplied from the burner to the boiler.

[0082] In the fuel supply device according to the present disclosure, a flow rate detection unit (60) may be provided that is disposed in the first pipe and detects the flow rate of the liquid fuel flowing through the first pipe, and a control unit (90) may be provided that controls the supply pump so that the flow rate detected by the flow rate detection unit becomes a predetermined target flow rate. According to the fuel supply device of this configuration, by controlling the supply pump so that the flow rate of the liquid fuel detected by the flow rate detection unit disposed in the first pipe becomes a predetermined target flow rate, the amount of liquid fuel necessary for adjusting the pressure inside the pressure vessel is held in the pressure vessel, and the liquid fuel of the predetermined target flow rate can be supplied from the burner to the boiler.

[0083] In the fuel supply device according to the present disclosure, a liquid fuel detection unit (70) may be provided that detects the amount of the liquid fuel held in the pressure vessel, and a control unit (90) may be provided that controls the supply pump so that the amount of the liquid fuel detected by the liquid fuel detection unit becomes a predetermined target amount. According to the fuel supply device of this configuration, by controlling the supply pump so that the amount of the liquid fuel held in the pressure vessel detected by the liquid fuel detection unit becomes a predetermined target amount, the amount of liquid fuel necessary for adjusting the pressure inside the pressure vessel is held in the pressure vessel, and the liquid fuel of the predetermined target flow rate can be supplied from the burner to the boiler.

[0084] In the fuel supply device according to the present disclosure, it may be configured to include a fuel gas detection unit (70C) that detects the amount of the fuel gas held in the pressure vessel, and a control unit (90) that controls the flow rate adjustment unit so that the amount of the fuel gas detected by the fuel gas detection unit becomes smaller than a predetermined target amount. According to the fuel supply device of this configuration, even if the fuel gas is mixed into the liquid fuel and supplied to the pressure vessel, the fuel gas is separated in the pressure vessel so that the fuel gas is not supplied to the burner, and it is possible to avoid the combustion in the burner becoming unstable.

[0085] In the fuel supply device according to the present disclosure, it is preferable that the liquid fuel is a liquid fuel having a boiling point of 80°C or lower at atmospheric pressure.

[0086] In the fuel supply device according to the above configuration, it is preferable that the liquid fuel is ammonia, an aqueous ammonia solution, dimethyl ether, methanol, an aqueous methanol solution, ethanol, an aqueous ethanol solution, naphtha, or crude oil.

[0087] The control method of the fuel supply device described in the above-described embodiment is understood as follows, for example. The control method of the fuel supply device according to the present disclosure is a control method of a fuel supply device that supplies liquid fuel to a burner. The fuel supply device includes a pressure vessel that holds the liquid fuel and fuel gas vaporized from the liquid fuel, and a first pipe that guides the liquid fuel from the pressure vessel to the burner. The control method includes a control step of adjusting the flow rate of the liquid fuel supplied from the pressure vessel to the burner through the first pipe by adjusting the pressure inside the pressure vessel.

[0088] According to the control method of the fuel supply device according to the present disclosure, a liquid fuel and a fuel gas vaporized from the liquid fuel are held in a pressure vessel, and the control step adjusts the pressure inside the pressure vessel, thereby adjusting the flow rate of the liquid fuel supplied from the pressure vessel to the burner. Since a valve for reducing the pressure of the liquid fuel is not provided in the first pipe that guides the liquid fuel from the pressure vessel to the burner, the liquid fuel can be stably supplied to the burner without vaporizing the liquid fuel in the first pipe.

Description of Signs

[0089] 10 Storage tank (pressure vessel) 20 Pressure vessel 30 Supply pump 40, 40C Flow rate adjustment unit 41, 41C Heating unit 41a, 41b, 41c, 41Ca Heater 42, 42C, 43 Pressure regulating valve 42D Discharge valve 50 Pressure sensor (pressure detection unit) 60 Flow rate detection unit 70 Liquid fuel detection unit 90 Control unit 100, 100A, 100B, 100C, 100D Fuel supply device 200 Boiler 210 Burner A1, B1 Liquid phase region A2, B2 Gas phase region L1 First pipe L2 Second pipe L3 Third pipe L4 Fourth pipe Pt Target pressure Q Heating amount

Claims

1. A fuel supply device for supplying liquid fuel to a burner, comprising: a pressure vessel for holding the liquid fuel and fuel gas vaporized from the liquid fuel; a first pipe for guiding the liquid fuel from the pressure vessel to the burner; a flow rate adjustment unit that adjusts the internal pressure of the pressure vessel to adjust the flow rate of the liquid fuel supplied from the pressure vessel to the burner via the first pipe.

2. a storage unit for storing the liquid fuel; a second pipe for guiding the liquid fuel from the storage unit to the pressure vessel; The fuel supply device according to claim 1, further comprising a supply pump disposed in the second pipe for supplying the liquid fuel from the storage unit to the pressure vessel.

3. The fuel supply device according to claim 1 or 2, wherein the flow rate adjustment unit has a heating unit that vaporizes the liquid fuel by heating the liquid fuel to increase the internal pressure of the pressure vessel.

4. The fuel supply device according to claim 3, wherein the flow rate adjustment unit has a plurality of the heating units with different heat amounts changeable per unit time.

5. The fuel supply device according to any one of claims 1 to 4, further comprising a third pipe connected to the upper part of the pressure vessel for guiding the fuel gas held in the pressure vessel to the outside, wherein the flow rate adjustment unit has a pressure adjustment valve disposed in the third pipe for adjusting the internal pressure of the pressure vessel.

6. The fuel supply device according to claim 5, wherein the flow rate adjustment unit has a plurality of the pressure adjustment valves with different valve capacities.

7. The fuel supply device according to any one of claims 1 to 6, further comprising a pressure detection unit disposed in the first pipe for detecting the pressure of the liquid fuel flowing through the first pipe, wherein the flow rate adjustment unit adjusts the internal pressure of the pressure vessel so that the pressure detected by the pressure detection unit becomes a predetermined target pressure.

8. The fuel supply device according to claim 2, further comprising a flow rate detection unit disposed in the first pipe for detecting the flow rate of the liquid fuel flowing through the first pipe, and a control unit for controlling the supply pump so that the flow rate detected by the flow rate detection unit becomes a predetermined target flow rate.

9. a liquid fuel detection unit for detecting the amount of the liquid fuel held in the pressure vessel A control unit that controls the supply pump so that the amount of the liquid fuel detected by the liquid fuel detection unit becomes a predetermined target amount, the fuel supply device according to claim 2.

10. A fuel gas detection unit that detects the amount of the fuel gas held in the pressure vessel, A control unit that controls the flow rate adjustment unit so that the amount of the fuel gas detected by the fuel gas detection unit becomes smaller than a predetermined target amount, the fuel supply device according to any one of claims 1 to 9.

11. The liquid fuel is a liquid fuel having a boiling point of 80 ° C or lower at atmospheric pressure, the fuel supply device according to any one of claims 1 to 10.

12. The liquid fuel is ammonia, aqueous ammonia, dimethyl ether, methanol, aqueous methanol solution, ethanol, aqueous ethanol solution, naphtha, or crude oil, the fuel supply device according to any one of claims 1 to 10.

13. A control method for a fuel supply device that supplies liquid fuel to a burner, The fuel supply device is A pressure vessel that holds the liquid fuel and the fuel gas vaporized from the liquid fuel, A first pipe that guides the liquid fuel from the pressure vessel to the burner, and A control method for a fuel supply device including a control step of adjusting the flow rate of the liquid fuel supplied from the pressure vessel to the burner through the first pipe by adjusting the pressure inside the pressure vessel.

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