Ammonia receiving facility

Abstract

The present invention comprises: a boil-off gas supply unit (4) that is able to supply a boil-off gas (G) produced in an ammonia tank (2) to an ammonia gas delivery unit (3); a nitrogen gas recovery unit (5) that supplies nitrogen gas (N) recovered from a nitrogen gas-using device to the boil-off gas supply unit (4) and mixes the nitrogen gas (N) with the boil-off gas (G); a gas analyzer (7) that detects the amount of heat of the ammonia gas delivered from the ammonia gas delivery unit (3); a treatment facility (6) that separates the nitrogen gas (N) from the boil-off gas and is able to supply the same to a ground flare (F); and a control unit (8) that causes the boil-off gas supply unit (4) to supply the boil-off gas (G) to the treatment facility (6) if the amount of heat of the gas is lower than a predetermined threshold.

Description

Ammonia Receiving Facility

[0001] This disclosure relates to an ammonia receiving facility. This application claims priority to Japanese Patent Application No. 2024-006364, filed on January 18, 2024, the contents of which are incorporated herein by reference.

[0002] For example, Patent Document 1 discloses a combustion device capable of burning ammonia as fuel. The combustion device disclosed in Patent Document 1 is installed in a boiler, and ammonia supplied from an ammonia supply source is mixed and burned together with pulverized coal.

[0003] Japanese Patent Application Publication No. 2019-86189

[0004] Large-scale power generation boilers that use LNG (Liquefied Natural Gas) or LPG (Liquefied Petroleum Gas) as fuel are equipped with receiving facilities for storing LNG and other fuels. These receiving facilities vaporize fuels such as LNG and supply the required amount of vaporized gas to boilers and gas turbines. These receiving facilities are equipped with equipment that uses nitrogen gas for maintenance, rotating equipment shaft sealing, process fluid replacement, and other purposes. Because the nitrogen gas used in these operations contains vaporized gases such as LNG, it is often returned to the process piping and ultimately delivered to the power generation facility as part of the fuel gas. However, ammonia gas is less flammable than fossil fuels such as LNG and LPG. Therefore, supplying a large amount of nitrogen gas, an inert gas, to a boiler may hinder stable combustion. However, because ammonia gas is toxic, it must be detoxified using a ground flare or other abatement equipment before being released to the atmosphere. If the entire amount of nitrogen gas mixed with ammonia were to be treated using a ground flare or other abatement equipment, the abatement equipment would be large. Furthermore, if abatement equipment requires large amounts of fossil fuels, it would go against the modern need to move toward decarbonization.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and aims to make it possible to reduce the amount of nitrogen gas recovered from nitrogen gas-using equipment supplied to abatement equipment in an ammonia receiving facility that vaporizes ammonia liquid and supplies it to a destination.

[0006] The present disclosure employs the following configuration as a means for solving the above problems.

[0007] ammonia gas delivery unit that vaporizes the ammonia liquid and delivers it to a supply destination; a boil-off gas supply unit that can supply boil-off gas generated in the ammonia tank to the ammonia gas delivery unit; a nitrogen gas recovery unit that supplies nitrogen gas recovered from a nitrogen gas-using device to the boil-off gas supply unit and mixes it with the boil-off gas; a gas calorific value detection unit that detects the gas calorific value of the ammonia gas delivered from the ammonia gas delivery unit; treatment equipment that can separate and process the nitrogen gas from the boil-off gas and supply it to abatement equipment; and a control unit that causes the boil-off gas supply unit to supply the boil-off gas to the treatment equipment when the gas calorific value is lower than a predetermined threshold.

[0008] According to the present disclosure, nitrogen gas recovered in the nitrogen gas recovery unit is mixed with boil-off gas, and further mixed with ammonia gas (vaporized gas), and then delivered to the destination. If the calorific value of the ammonia gas delivered to the destination is higher than a predetermined threshold, the boil-off gas is delivered to the destination. On the other hand, if the calorific value of the ammonia gas delivered to the destination is lower than a predetermined threshold, the boil-off gas is delivered to, for example, a treatment facility without being delivered to a gas delivery pipe. When boil-off gas is delivered to the treatment facility, for example, nitrogen-rich gas that has not been reliquefied in a condenser is separated from the boil-off gas and delivered to abatement equipment. Thus, according to the present disclosure, nitrogen gas is delivered to the abatement equipment only when the concentration of nitrogen gas contained in the ammonia gas delivered to the destination is high and the calorific value of the mixed gas is lower than a predetermined threshold. Therefore, according to the present disclosure, in an ammonia receiving facility that vaporizes ammonia liquid and delivers it to a destination, the amount of nitrogen gas recovered from a nitrogen-using device supplied to abatement equipment can be reduced.

[0009] Fig. 1 is a flow chart showing a schematic configuration of an ammonia receiving facility according to a first embodiment of the present disclosure. Fig. 2 is a flow chart for explaining the operation of a control unit provided in the ammonia receiving facility according to the first embodiment of the present disclosure. Fig. 3 is a flow chart showing a schematic configuration of an ammonia receiving facility according to a second embodiment of the present disclosure.

[0010] Hereinafter, an embodiment of an ammonia receiving facility according to the present disclosure will be described with reference to the drawings.

[0011] (First embodiment) Fig. 1 is a flow diagram showing a schematic configuration of an ammonia receiving facility 1 of this embodiment. The ammonia receiving facility 1 of this embodiment stores ammonia liquid X. The ammonia receiving facility 1 of this embodiment also vaporizes the stored ammonia liquid X to produce ammonia gas Y. The ammonia receiving facility 1 of this embodiment also supplies a required amount of ammonia gas Y to a boiler B (supply destination). Note that the supply destination of the ammonia gas Y from the ammonia receiving facility 1 is not limited to the boiler B and can also be a gas turbine or the like.

[0012] As shown in FIG. 1 , the ammonia receiving facility 1 of this embodiment includes an ammonia tank 2, an ammonia gas delivery unit 3, a boil-off gas supply unit 4, a nitrogen gas recovery unit 5, a treatment facility 6, a gas analyzer 7 (gas calorific value detection unit), and a control unit 8.

[0013] The ammonia tank 2 is a tank that stores ammonia liquid X. The ammonia tank 2 stores the ammonia liquid X supplied from the outside while maintaining it at a low temperature. The ammonia tank 2 is, for example, a double-shell tank made of PC concrete, which has a metal inner shell and a PC concrete dike. The ammonia tank 2 has, for example, a cold insulation material filled between the dike and the inner shell, and stores the ammonia liquid X inside the inner shell at a low temperature. However, the structure of the ammonia tank 2 is not particularly limited.

[0014] The ammonia gas delivery unit 3 vaporizes the ammonia liquid X and delivers it toward the boiler B. As shown in FIG. 1 , the ammonia gas delivery unit 3 includes a delivery pump 3a, a delivery pipe 3b, a vaporization facility 3c, and a gas delivery pipe 3d.

[0015] The discharge pump 3a is disposed inside the ammonia tank 2, and pumps the ammonia liquid X stored in the ammonia tank 2 to the outside of the ammonia tank 2. The discharge pump 3a is connected to, for example, the control unit 8, and discharges a designated amount of ammonia liquid X to the outside of the ammonia tank 2 based on the control of the control unit 8.

[0016] The discharge pipe 3b is a pipe that connects the ammonia tank 2 and the vaporization equipment 3c. The upstream end of the discharge pipe 3b is connected to the ammonia tank 2, and the downstream end of the discharge pipe 3b is connected to the vaporization equipment 3c. The discharge pipe 3b guides the ammonia liquid X discharged by the discharge pump 3a from the ammonia tank 2 to the vaporization equipment 3c.

[0017] The vaporization equipment 3c heats and vaporizes the ammonia liquid X. The vaporization equipment 3c vaporizes the ammonia liquid X supplied from the ammonia tank 2 via the discharge pipe 3b. For example, a heating fluid supply unit (not shown) is connected to the vaporization equipment 3c, and a heating fluid such as seawater is supplied to the vaporization equipment 3c. The vaporization equipment 3c vaporizes the ammonia liquid X by exchanging heat between the ammonia liquid X and the heating fluid such as seawater.

[0018] The gas supply pipe 3d is a pipe that connects the vaporization equipment 3c and the boiler B. The upstream end of the gas supply pipe 3d is connected to the vaporization equipment 3c, and the downstream end of the gas supply pipe 3d is connected to the boiler B. The downstream end of the gas supply pipe 3d does not have to be directly connected to the boiler B. In other words, the downstream end of the gas supply pipe 3d may be connected to the boiler B via another device or the like. The gas supply pipe 3d guides the ammonia gas Y discharged from the vaporization equipment 3c from the vaporization equipment 3c to the boiler B.

[0019] The vaporization equipment 3c may include a superheater at a midpoint of the gas supply pipe 3d. The superheater vaporizes the mist-like ammonia liquid X contained in the ammonia gas Y flowing through the gas supply pipe 3d.

[0020] The boil-off gas supply unit 4 is capable of supplying the boil-off gas G generated in the ammonia tank 2 to the ammonia gas delivery unit 3. As shown in Fig. 1 , the boil-off gas supply unit 4 includes a boil-off gas main pipe 4a (first pipe), a first on-off valve 4b, a boil-off gas treatment facility connection pipe 4c (second pipe), a second on-off valve 4d, a boil-off gas compressor 4e, and an emergency exhaust pipe 4f.

[0021] The boil-off gas main pipe 4a is a pipe connected to the ammonia gas delivery unit 3. The upstream end of the boil-off gas main pipe 4a is connected to the ammonia tank 2, and the downstream end of the boil-off gas main pipe 4a is connected to the ammonia gas delivery unit 3. The downstream end of the boil-off gas main pipe 4a is connected to the gas delivery pipe 3d of the ammonia gas delivery unit 3. The boil-off gas main pipe 4a guides the boil-off gas G generated inside the ammonia tank 2 from the ammonia tank 2 to the gas delivery pipe 3d.

[0022] The first on-off valve 4b is an on-off valve installed at an intermediate position of the boil-off gas main pipe 4a. The first on-off valve 4b is opened and closed under the control of the control unit 8. The first on-off valve 4b is located at an intermediate position of the boil-off gas main pipe 4a, near the downstream end of the boil-off gas main pipe 4a. The first on-off valve 4b is located downstream of the portion of the boil-off gas main pipe 4a where the boil-off gas treatment facility connection pipe 4c is connected. The boil-off gas G is supplied to the gas transmission pipe 3d with the first on-off valve 4b open. Furthermore, closing the first on-off valve 4b stops the supply of the boil-off gas G to the gas transmission pipe 3d.

[0023] The boil-off gas treatment equipment connection pipe 4c is a pipe that connects the boil-off gas main pipe 4a and the treatment equipment 6. The upstream end of the boil-off gas treatment equipment connection pipe 4c is connected to the boil-off gas main pipe 4a, and the downstream end of the boil-off gas treatment equipment connection pipe 4c is connected to the treatment equipment 6. The upstream end of the boil-off gas treatment equipment connection pipe 4c is connected to the boil-off gas main pipe 4a at a position upstream of the first on-off valve 4b. In other words, the boil-off gas treatment equipment connection pipe 4c connects the treatment equipment 6 to a position upstream of the first on-off valve 4b of the boil-off gas main pipe 4a. The boil-off gas treatment equipment connection pipe 4c guides the boil-off gas G from the boil-off gas main pipe 4a to the treatment equipment 6. The downstream end of the boil-off gas treatment equipment connection pipe 4c is connected to a condenser 6a (described later) of the treatment equipment 6.

[0024] The second on-off valve 4d is an on-off valve installed at an intermediate position of the boil-off gas treatment facility connecting pipe 4c. The second on-off valve 4d is opened and closed under the control of the control unit 8. The boil-off gas G is supplied to the treatment facility 6 when the second on-off valve 4d is open. When the second on-off valve 4d is closed, the supply of the boil-off gas G to the treatment facility 6 is stopped.

[0025] The boil-off gas compressor 4e is a compressor that pressurizes the boil-off gas G flowing through the boil-off gas main pipe 4a, and is installed at a midpoint of the boil-off gas main pipe 4a. The boil-off gas compressor 4e is located upstream of the portion of the boil-off gas main pipe 4a where the boil-off gas treatment facility connection pipe 4c is connected. The boil-off gas compressor 4e compresses and pressurizes the boil-off gas G to a pressure that allows the boil-off gas G to be supplied to the gas delivery pipe 3d and the treatment facility 6.

[0026] The emergency exhaust pipe 4f is a pipe for supplying the boil-off gas G to a ground flare F (abatement equipment) when the pressure of the boil-off gas G becomes abnormally high. The upstream end of the emergency exhaust pipe 4f is connected to the boil-off gas main pipe 4a, and the downstream end of the emergency exhaust pipe 4f is connected to a boil-off gas release valve 6d (described later) of the treatment equipment 6. The upstream end of the emergency exhaust pipe 4f is connected to the boil-off gas main pipe 4a at a position upstream of the boil-off gas compressor 4e.

[0027] Furthermore, in this embodiment, the emergency exhaust pipe 4f functions as a pipe that normally guides the nitrogen gas N recovered by the nitrogen gas recovery unit 5. The nitrogen gas recovery unit 5 is connected to a midpoint of the emergency exhaust pipe 4f. Under normal conditions (when the boil-off gas release valve 6d is closed), the emergency exhaust pipe 4f allows the nitrogen gas N supplied from the nitrogen gas recovery unit 5 to flow into the boil-off gas main pipe 4a. In other words, the nitrogen gas N recovered by the nitrogen gas recovery unit 5 flows through the emergency exhaust pipe 4f toward the boil-off gas main pipe 4a and is supplied to the boil-off gas main pipe 4a.

[0028] The nitrogen gas recovery section 5 supplies the nitrogen gas N recovered from the nitrogen gas-using equipment to the boil-off gas supply section 4 and mixes it with the boil-off gas G. As shown in FIG. 1 , the nitrogen gas recovery section 5 is composed of a pipe that guides the nitrogen gas N from the nitrogen gas recovery section 5 to the boil-off gas main pipe 4a of the boil-off gas supply section 4. The upstream section of the nitrogen gas recovery section 5 is branched into a plurality of pipes. The upstream end of each of the branched pipes is connected to a nitrogen gas-using equipment.

[0029] In this embodiment, the ammonia tank 2, the vaporization equipment 3c, and the gas analyzer 7 are nitrogen gas-using equipment. For example, the ammonia tank 2 uses nitrogen gas N as a purge gas. The vaporization equipment 3c uses nitrogen gas N as a purge gas and a seal gas. The gas analyzer 7 takes in boil-off gas G containing nitrogen gas N, analyzes it, and then exhausts it. In other words, the nitrogen gas N used in the ammonia tank 2, the vaporization equipment 3c, and the gas analyzer 7 is supplied to the boil-off gas main pipe 4a of the boil-off gas supply unit 4 via the nitrogen gas recovery unit 5.

[0030] The treatment equipment 6 is capable of separating and treating nitrogen gas N from boil-off gas G and supplying the nitrogen gas N to the ground flare F. Furthermore, when the pressure in the ammonia tank 2 abnormally increases, the treatment equipment 6 is capable of receiving boil-off gas G through the emergency exhaust pipe 4 f and supplying the boil-off gas G received from the emergency exhaust pipe 4 f to the ground flare F. As shown in FIG. 1 , the treatment equipment 6 includes a condenser 6 a, a nitrogen gas discharge section 6 b (discharge section), a boil-off gas receiving pipe 6 c, and a boil-off gas release valve 6 d.

[0031] When the boil-off gas G is supplied from the boil-off gas supply unit 4, the condenser 6a condenses the boil-off gas G. When the second on-off valve 4d is opened, the boil-off gas G is supplied from the boil-off gas supply unit 4 to the condenser 6a. The boil-off gas G is condensed inside the condenser 6a and liquefied to become ammonia liquid X. When the boil-off gas G supplied to the condenser 6a contains nitrogen gas N, the nitrogen gas N contained in the boil-off gas G is not liquefied inside the condenser 6a and accumulates in the condenser 6a as a gas.

[0032] The nitrogen gas discharge unit 6b supplies the nitrogen gas N accumulated inside the condenser 6a to the ground flare F. The nitrogen gas discharge unit 6b includes a nitrogen gas pipe 6b1 and a nitrogen gas release valve 6b2.

[0033] The nitrogen gas pipe 6b1 is a pipe that connects the condenser 6a and the ground flare F. The upstream end of the nitrogen gas pipe 6b1 is connected to the condenser 6a, and the downstream end of the nitrogen gas pipe 6b1 is connected to the ground flare F. The nitrogen gas pipe 6b1 guides the nitrogen gas N from the condenser 6a to the ground flare F.

[0034] The nitrogen gas release valve 6b2 is a release valve installed midway along the nitrogen gas pipe 6b1. The nitrogen gas release valve 6b2 opens when the internal pressure of the condenser 6a exceeds a predetermined threshold. The internal pressure of the condenser 6a increases as nitrogen gas N accumulates. When the internal pressure of the condenser 6a exceeds the predetermined threshold and the nitrogen gas release valve 6b2 opens, the nitrogen gas N inside the condenser 6a flows into the nitrogen gas pipe 6b1.

[0035] When the nitrogen gas release valve 6b2 is opened, part of the boil-off gas G inside the condenser 6a flows into the nitrogen gas pipe 6b1 along with the flow of the nitrogen gas N. The boil-off gas G that has flowed into the nitrogen gas pipe 6b1 is incinerated in the ground flare F and rendered harmless.

[0036] The ground flare F incinerates the boil-off gas G contained in the supplied nitrogen gas N. When the amount of boil-off gas G contained in the supplied nitrogen gas N is small, the ground flare F inputs a fossil fuel such as LPG and burns the ammonia. In other words, the ground flare F burns the ammonia together with the fuel. Note that the ground flare F is also supplied with boil-off gas G received by the treatment facility 6 via the emergency exhaust pipe 4f. The ground flare F also incinerates such boil-off gas G. Note that the ground flare F may be replaced with a flare facility such as a flare stack.

[0037] The gas analyzer 7 is a gas calorific value detection unit that detects the gas calorific value of the ammonia gas Y delivered from the ammonia gas delivery unit 3 to the boiler B. In this embodiment, two gas analyzers 7 are provided: a first gas analyzer 7a (first gas calorific value detection unit) and a second gas analyzer 7b (second gas calorific value detection unit).

[0038] 1, the first gas analyzer 7a is provided at a midpoint of the gas transmission pipe 3d of the ammonia gas delivery unit 3. The first gas analyzer 7a is disposed downstream of the position where the boil-off gas main pipe 4a of the gas transmission pipe 3d is connected. The first gas analyzer 7a detects the gas calorific value of the ammonia gas Y supplied from the gas transmission pipe 3d to the boiler B. The first gas analyzer 7a inputs the detected gas calorific value to the control unit 8.

[0039] 1, the second gas analyzer 7b is provided at a midpoint of the boil-off gas main pipe 4a of the boil-off gas supply unit 4. The second gas analyzer 7b is disposed upstream of the position where the boil-off gas main pipe 4a is connected to the boil-off gas treatment facility connection pipe 4c. The second gas analyzer 7b detects the gas calorific value of the boil-off gas G flowing through the boil-off gas main pipe 4a. The second gas analyzer 7b may be omitted.

[0040] The second gas analyzer 7b obtains, for example, flow rate information of the ammonia gas Y supplied from the ammonia gas delivery unit 3 to the boiler B via the control unit 8. Based on the obtained flow rate information of the ammonia gas Y, the second gas analyzer 7b calculates the gas calorific value of the ammonia gas Y when the boil-off gas G flowing through the boil-off gas main pipe 4a is mixed with the ammonia gas Y. The second gas analyzer 7b inputs the gas calorific value of the ammonia gas Y calculated in this manner to the control unit 8.

[0041] The calculation of the gas calorific value of the ammonia gas Y may be performed by the control unit 8. In this case, the second gas analyzer 7b detects the gas calorific value of the boil-off gas G flowing through the boil-off gas main pipe 4a and inputs the detected gas calorific value to the control unit 8. In this way, the detection of the gas calorific value of the ammonia gas Y by the gas analyzer 7 is not limited to directly detecting the gas calorific value of the ammonia gas Y to be delivered, but also includes detecting a value from which the gas calorific value of the ammonia gas Y to be delivered to the boiler B can be calculated.

[0042] The control unit 8 is connected to each gas analyzer 7 (the first gas analyzer 7a and the second gas analyzer 7b) and can acquire the gas calorific value of the ammonia gas Y supplied to the boiler B. The control unit 8 is also connected to each of the first on-off valve 4b and the second on-off valve 4d and can control the opening and closing of each of the first on-off valve 4b and the second on-off valve 4d.

[0043] The control unit 8 causes the boil-off gas supply unit 4 to supply the boil-off gas G to the treatment facility 6 when the gas calorific value of the ammonia gas Y delivered to the boiler B is lower than a predetermined threshold value. Also, when the gas calorific value of the ammonia gas Y delivered to the boiler B is higher than a predetermined threshold value, the control unit 8 causes the boil-off gas supply unit 4 to supply the boil-off gas G to the ammonia gas delivery unit 3.

[0044] Specifically, when the gas calorific value of the ammonia gas Y delivered to the boiler B is lower than a predetermined threshold, the control unit 8 closes the first on-off valve 4 b and opens the second on-off valve 4 d, thereby supplying the boil-off gas G from the boil-off gas supply unit 4 to the treatment facility 6.

[0045] Furthermore, when the gas calorific value of the ammonia gas Y delivered to the boiler B is higher than a predetermined threshold, the control unit 8 opens the first on-off valve 4 b and closes the second on-off valve 4 d, thereby supplying the boil-off gas G from the boil-off gas supply unit 4 to the ammonia gas delivery unit 3.

[0046] Next, the operation of the ammonia receiving facility 1 of this embodiment will be described. As shown in Fig. 1, ammonia liquid X stored in an ammonia tank 2 is discharged from the ammonia tank 2 by a discharge pump 3a and supplied to a vaporization facility 3c. The ammonia liquid X supplied to the vaporization facility 3c is vaporized to become ammonia gas Y. The ammonia gas Y discharged from the vaporization facility 3c is sent to a boiler B.

[0047] On the other hand, the boil-off gas G generated inside the ammonia tank 2 is discharged from the ammonia tank 2 and then compressed by the boil-off gas compressor 4e to be pressurized. If the gas calorific value of the ammonia gas Y delivered to the boiler B is higher than a predetermined threshold, the pressurized boil-off gas G is supplied to the ammonia gas delivery unit 3 and mixed with the ammonia gas Y. If the gas calorific value of the ammonia gas Y delivered to the boiler B is lower than a predetermined threshold, the pressurized boil-off gas G is supplied to the treatment facility 6.

[0048] The boil-off gas G supplied to the treatment facility 6 is condensed in the condenser 6a to become ammonia liquid X. The ammonia liquid X produced in the condenser 6a is discharged from the condenser 6a and returned to the ammonia tank 2 via, for example, an economizer (not shown). Meanwhile, the nitrogen gas N accumulated inside the condenser 6a is supplied to the ground flare F, where the contained ammonia is incinerated.

[0049] Fig. 2 is a flowchart for explaining an example of the control of the control unit 8. As shown in Fig. 2, the control unit 8 acquires the gas calorific value of the ammonia gas Y sent to the boiler B based on signals input from the first gas analyzer 7a and the second gas analyzer 7b (step S1).

[0050] Next, the control unit 8 determines whether the gas calorific value of the ammonia gas Y obtained in step S1 exceeds a preset threshold value (step S2). The threshold value here is set based on the gas calorific value that can be received by the boiler B. If the gas calorific value does not exceed the preset threshold value, the control unit 8 closes the first on-off valve 4b and opens the second on-off valve 4d (step S3), causing the boil-off gas supply unit 4 to supply the boil-off gas G to the treatment facility 6. On the other hand, if the gas calorific value exceeds the preset threshold value, the control unit 8 opens the first on-off valve 4b and closes the second on-off valve 4d (step S4), causing the boil-off gas supply unit 4 to supply the boil-off gas G to the ammonia gas delivery unit 3. After steps S3 and S4, the control unit 8 returns to step S1.

[0051] The ammonia receiving equipment 1 of this embodiment as described above includes an ammonia tank 2 and an ammonia gas delivery unit 3. The ammonia tank 2 stores ammonia liquid X. The ammonia gas delivery unit 3 vaporizes the ammonia liquid X and delivers it to the boiler B. The ammonia receiving equipment 1 of this embodiment also includes a boil-off gas supply unit 4, a nitrogen gas recovery unit 5, a gas analyzer 7, treatment equipment 6, and a control unit 8. The boil-off gas supply unit 4 is capable of supplying boil-off gas G generated in the ammonia tank 2 to the ammonia gas delivery unit 3. The nitrogen gas recovery unit 5 supplies nitrogen gas N recovered from a nitrogen gas-using device to the boil-off gas supply unit 4 and mixes it with the boil-off gas G. The gas analyzer 7 detects the gas calorific value of the ammonia gas delivered from the ammonia gas delivery unit 3. The treatment equipment 6 is capable of separating and treating nitrogen gas N from the boil-off gas and supplying it to the ground flare F. The control unit 8 causes the boil-off gas supply unit 4 to supply the boil-off gas G to the treatment facility 6 when the gas calorific value is lower than a predetermined threshold value.

[0052] According to the ammonia receiving equipment 1 of this embodiment, the nitrogen gas N recovered in the nitrogen gas recovery section 5 is mixed with the boil-off gas G, and further mixed with the ammonia gas Y, and then delivered to the boiler B. When the gas calorific value of the ammonia gas Y delivered to the boiler B is higher than a predetermined threshold, the boil-off gas G is supplied to the boiler B. On the other hand, when the gas calorific value of the ammonia gas Y delivered to the boiler B is lower than a predetermined threshold, the boil-off gas G is supplied to the treatment equipment 6. When the boil-off gas G is supplied to the treatment equipment 6, the nitrogen gas N is separated from the boil-off gas G and supplied to the ground flare F. In this way, the ammonia receiving equipment 1 of this embodiment supplies the nitrogen gas N to the ground flare F only when the gas calorific value of the ammonia gas Y delivered to the boiler B is lower than a predetermined threshold. Therefore, according to the ammonia receiving equipment 1 of this embodiment, in the ammonia receiving equipment 1 that vaporizes the ammonia liquid X and supplies it to the boiler B, the amount of the nitrogen gas N recovered from the nitrogen gas-using equipment that is supplied to the ground flare F can be suppressed.

[0053] In the ammonia receiving facility 1 of this embodiment, the boil-off gas supply unit 4 includes a boil-off gas main pipe 4a, a first on-off valve 4b, a boil-off gas treatment facility connection pipe 4c, and a second on-off valve 4d. The boil-off gas main pipe 4a is connected to the ammonia gas delivery unit 3. The first on-off valve 4b is installed in a middle portion of the boil-off gas main pipe 4a. The boil-off gas treatment facility connection pipe 4c connects the boil-off gas main pipe 4a upstream of the first on-off valve 4b to the treatment facility 6. The second on-off valve 4d is installed in a middle portion of the boil-off gas treatment facility connection pipe 4c. When the gas calorific value is lower than a threshold value, the control unit 8 closes the first on-off valve 4b and opens the second on-off valve 4d. When the gas calorific value is higher than a threshold value, the control unit 8 opens the first on-off valve 4b and closes the second on-off valve 4d.

[0054] In the ammonia-receiving facility 1 of this embodiment, the control unit 8 can open and close the first on-off valve 4 b and the second on-off valve 4 d. Therefore, the ammonia-receiving facility 1 of this embodiment can automatically change the supply destination of the boil-off gas G.

[0055] The ammonia receiving facility 1 of this embodiment also includes a first gas analyzer 7a and a second gas analyzer 7b. The first gas analyzer 7a detects the gas calorific value downstream of the first on-off valve 4b. The second gas analyzer 7b detects the gas calorific value upstream of the connection position of the boil-off gas treatment facility connection pipe 4c.

[0056] The ammonia receiving facility 1 of this embodiment can determine, using the first gas analyzer 7a, whether the gas calorific value of the ammonia gas Y has fallen below a threshold value. Also, the second gas analyzer 7b can determine, using the second gas analyzer 7b, whether the gas calorific value of the ammonia gas Y has exceeded a threshold value.

[0057] The second gas analyzer 7b can be used to determine whether the gas calorific value of the ammonia gas Y has fallen below the threshold value. Therefore, the first gas analyzer 7a can be omitted. However, by installing the first gas analyzer 7a, the gas calorific value can be detected immediately before the boiler B, and therefore the gas calorific value of the ammonia gas Y supplied to the boiler B can be measured more accurately.

[0058] In the ammonia receiving facility 1 of this embodiment, the treatment facility 6 includes a condenser 6 a and a nitrogen gas discharge unit 6 b. The condenser 6 a condenses the boil-off gas G. The nitrogen gas discharge unit 6 b supplies the nitrogen gas N accumulated inside the condenser 6 a to a ground flare F that detoxifies the ammonia.

[0059] According to the ammonia receiving facility 1 of this embodiment, the boil-off gas G is condensed in the condenser 6a, whereby the nitrogen gas N can be separated from the boil-off gas G. Therefore, the ammonia receiving facility 1 of this embodiment can separate the nitrogen gas N from the boil-off gas G with a simple configuration.

[0060] In the ammonia receiving facility 1 of this embodiment, the abatement facility is a ground flare F that burns ammonia together with fuel. The ammonia receiving facility 1 of this embodiment can suppress the amount of nitrogen gas N recovered from nitrogen gas-using equipment that is supplied to the ground flare F, thereby reducing the amount of fossil fuel consumed in the ground flare F.

[0061] In the ammonia receiving facility 1 of this embodiment, the ammonia tank 2, the ammonia gas delivery unit 3, and the gas analyzer 7 are nitrogen gas-using equipment. Therefore, the ammonia receiving facility 1 of this embodiment can appropriately process the nitrogen gas N discharged from the ammonia tank 2, the ammonia gas delivery unit 3, and the gas analyzer 7.

[0062] Second Embodiment Next, a second embodiment of the present disclosure will be described with reference to Fig. 3. In the description of this embodiment, the description of the same parts as those in the first embodiment will be omitted or simplified.

[0063] 3 is a flow diagram showing a schematic configuration of the ammonia receiving facility 1A of this embodiment. As shown in FIG. 3, the ammonia receiving facility 1A of this embodiment includes a loading arm 10 and a return gas blower 11.

[0064] The loading arm 10 is a facility for transferring the ammonia liquid X and the boil-off gas G between the ammonia ship transporting the ammonia liquid X and the ammonia receiving facility 1A of this embodiment. The loading arm 10 receives the ammonia liquid X from the ammonia ship and supplies the ammonia liquid X to the ammonia tank 2 via a pipe. The loading arm 10 also supplies the boil-off gas G pressure-fed by the return gas blower 11 to the ammonia ship. The return gas blower 11 is connected to the boil-off gas main pipe 4a of the boil-off gas supply unit 4, and supplies the boil-off gas G supplied from the boil-off gas main pipe 4a to the loading arm 10.

[0065] The loading arm 10 and the return gas blower 11 are nitrogen gas-using equipment that uses nitrogen gas N as a purge gas or a seal gas. The nitrogen gas N used in the loading arm 10 and the return gas blower 11 may contain ammonia. For this reason, in the ammonia receiving equipment 1A of this embodiment, the nitrogen gas recovery unit 5 also recovers nitrogen gas N from the loading arm 10 and the return gas blower 11.

[0066] According to the ammonia receiving facility 1A of this embodiment, it is possible to recover nitrogen gas N from the loading arm 10 and the return gas blower 11 and to appropriately treat the recovered nitrogen gas N.

[0067] While the preferred embodiments of the present disclosure have been described above with reference to the accompanying drawings, it goes without saying that the present disclosure is not limited to the above-described embodiments. The shapes and combinations of the components shown in the above-described embodiments are merely examples, and various modifications can be made based on design requirements, etc., without departing from the spirit of the present disclosure.

[0068] The above embodiment can also be described as follows, for example:

[0069] (Supplementary Note 1) An ammonia receiving facility comprising: an ammonia tank for storing ammonia liquid; an ammonia gas delivery unit for vaporizing the ammonia liquid and delivering it to a supply destination; a boil-off gas supply unit capable of supplying boil-off gas generated in the ammonia tank to the ammonia gas delivery unit; a nitrogen gas recovery unit for supplying nitrogen gas recovered from a nitrogen gas-using device to the boil-off gas supply unit and mixing it with the boil-off gas; a gas calorific value detection unit for detecting a gas calorific value of the ammonia gas delivered from the ammonia gas delivery unit; treatment equipment capable of separating and treating the nitrogen gas from the boil-off gas and supplying it to abatement equipment; and a control unit for causing the boil-off gas supply unit to supply the boil-off gas to the treatment equipment when the gas calorific value is lower than a predetermined threshold.

[0070] (Supplementary Note 2) The ammonia receiving facility according to Supplementary Note 1, wherein the boil-off gas supply unit includes: a first pipe connected to the ammonia gas delivery unit; a first on-off valve installed in a middle portion of the first pipe; a second pipe connecting the treatment facility to a position on the first pipe upstream of the first on-off valve; and a second on-off valve installed in a middle portion of the second pipe; and the control unit closes the first on-off valve and opens the second on-off valve when the gas calorific value is lower than the threshold value, and opens the first on-off valve and closes the second on-off valve when the gas calorific value is higher than the threshold value.

[0071] (Supplementary Note 3) The ammonia receiving facility according to Supplementary Note 2, wherein the gas calorific value detection unit includes: a first gas calorific value detection unit that detects the gas calorific value at a position downstream of the first on-off valve; and a second gas calorific value detection unit that detects the gas calorific value at a position upstream of a connection position of the second piping.

[0072] (Supplementary Note 4) The ammonia receiving facility according to any one of Supplementary Notes 1 to 3, wherein the treatment facility includes: a condenser that condenses the boil-off gas; and a discharge unit that supplies the nitrogen gas accumulated inside the condenser to a detoxification facility that detoxifies the ammonia.

[0073] (Supplementary Note 5) The ammonia receiving facility according to Supplementary Note 4, wherein the abatement facility is a flare facility that burns ammonia together with fuel.

[0074] (Supplementary Note 6) The ammonia receiving facility according to any one of Supplementary Notes 1 to 5, wherein at least one of the ammonia tank, the ammonia gas delivery unit, and the gas calorific value detection unit is the nitrogen gas-using equipment.

[0075] According to the present disclosure, in an ammonia receiving facility that vaporizes ammonia liquid and supplies it to a destination, the amount of nitrogen gas recovered from nitrogen gas-using equipment that is supplied to abatement equipment can be reduced.

[0076] 1...Ammonia receiving equipment, 1A...Ammonia receiving equipment, 2...Ammonia tank, 3...Ammonia gas delivery section, 3a...Delivery pump, 3b...Delivery piping, 3c...Vaporization equipment, 3d...Gas delivery piping, 4...Boil-off gas supply section, 4a...Boil-off gas main pipe (first piping), 4b...First on-off valve, 4c...Boil-off gas treatment equipment connection piping (second piping), 4d...Second on-off valve, 4e...Boil-off gas compressor, 4f...Emergency exhaust pipe, 5...Nitrogen gas recovery section, 6...Treatment equipment, 6a...Condenser, 6b...Nitrogen gas exhaust outlet, 6b1...nitrogen gas piping, 6b2...nitrogen gas release valve, 6c...boil-off gas receiving piping, 6d...boil-off gas release valve, 7...gas analyzer (gas calorific value detection unit), 7a...first gas analyzer (first gas calorific value detection unit), 7b...second gas analyzer (second gas calorific value detection unit), 8...control unit, 10...loading arm, 11...return gas blower, B...boiler (supply destination), F...ground flare (abatement equipment, flare equipment), G...boil-off gas, N...nitrogen gas, X...ammonia liquid, Y...ammonia gas

Claims

1. An ammonia receiving facility comprising: an ammonia tank for storing ammonia liquid; an ammonia gas sending unit for vaporizing the ammonia liquid and sending it toward a supply destination; a boil-off gas supply unit capable of supplying boil-off gas generated in the ammonia tank to the ammonia gas sending unit; a nitrogen gas recovery unit for supplying nitrogen gas recovered from nitrogen gas-using equipment to the boil-off gas supply unit and mixing it with the boil-off gas; a gas calorific value detection unit for detecting the calorific value of the ammonia gas sent out from the ammonia gas sending unit; a processing facility capable of separating the nitrogen gas from the boil-off gas and supplying it to a decontamination facility; and a control unit for causing the boil-off gas supply unit to supply the boil-off gas to the processing facility when the gas calorific value is lower than a predetermined threshold value.

2. The boil-off gas supply unit includes: a first pipe connected to the ammonia gas sending unit; a first on-off valve installed at an intermediate position of the first pipe; a second pipe connecting an upstream position of the first pipe from the first on-off valve and the processing facility; and a second on-off valve installed at an intermediate position of the second pipe. The control unit closes the first on-off valve and opens the second on-off valve when the gas calorific value is lower than the threshold value, and opens the first on-off valve and closes the second on-off valve when the gas calorific value is higher than the threshold value. The ammonia receiving facility according to claim 1.

3. The gas calorific value detection unit includes: a first gas calorific value detection unit for detecting the gas calorific value at a position downstream of the first on-off valve; and a second gas calorific value detection unit for detecting the gas calorific value at a position upstream of the connection position of the second pipe. The ammonia receiving facility according to claim 2.

4. The processing facility includes: a condenser for condensing the boil-off gas; and a discharge unit for supplying the nitrogen gas accumulated inside the condenser to a decontamination facility for decontaminating ammonia. The ammonia receiving facility according to any one of claims 1 to 3.

5. The decontamination facility is a flare facility that burns ammonia together with fuel. The ammonia receiving facility according to claim 4.

6. At least any one of the ammonia tank, the ammonia gas sending unit, and the gas calorific value detection unit is the nitrogen gas-using equipment. The ammonia receiving facility according to any one of claims 1 to 3.

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