Ammonia gas production device and method for modifying fuel gas consumption system

Abstract

An ammonia gas production device 100 comprises: a booster pump 110 that boosts liquid ammonia; a preheater 120 that preheats the liquid ammonia by exchanging heat between the liquid ammonia boosted by the booster pump 110 and a heat medium; a vaporizer 130 that vaporizes the liquid ammonia by exchanging heat between the liquid ammonia preheated by the preheater 120 and the heat medium; a superheater 140 that superheats the ammonia gas by exchanging heat between the ammonia gas vaporized by the vaporizer 130 and the heat medium; and a heat medium supply unit 160 that causes the heat medium to exchange heat in the superheater 140, the vaporizer 130, and the preheater 120 in this order. The ammonia gas superheated by the superheater 140 is supplied to a supply destination 102, and the discharge pressure of the booster pump 110 is equal to or higher than a required pressure required by the supply destination 102.

Description

Ammonia gas production apparatus and method for retrofitting a fuel gas consumption system

[0001] The present disclosure relates to an ammonia gas production apparatus and a method for retrofitting a fuel gas consumption system. This application claims the benefit of priority based on Japanese Patent Application No. 2024-195366 filed on November 7, 2024, the content of which is incorporated herein by reference.

[0002] In recent years, in order to prevent global warming, reduction of carbon dioxide (CO ２ 2) emissions has been demanded. For this reason, technologies for burning ammonia instead of fossil fuels have attracted attention.

[0003] For example, Patent Document 1 discloses an industrial furnace provided with a burner for burning ammonia gas together with combustion air and gas fuel on the side wall of a furnace body.

[0004] Japanese Patent Application Laid-Open No. 2024-126968

[0005] By the way, in recent years, in conventional technologies such as the technology of Patent Document 1, the use of high-pressure ammonia gas has been studied.

[0006] In view of such problems, an object of the present disclosure is to provide an ammonia gas production apparatus capable of efficiently producing high-pressure ammonia gas and a method for retrofitting a fuel gas consumption system.

[0007] To solve the above problems, an ammonia gas production apparatus according to one aspect of the present disclosure includes a pressure pump for boosting liquid ammonia, a preheater for preheating the liquid ammonia by heat-exchanging the liquid ammonia boosted by the pressure pump with a heat medium, a vaporizer for vaporizing the liquid ammonia by heat-exchanging the liquid ammonia preheated by the preheater with the heat medium, a superheater for superheating the ammonia gas by heat-exchanging the ammonia gas vaporized by the vaporizer with the heat medium, and a heat medium supply unit for heat-exchanging the heat medium in the order of the superheater, the vaporizer, and the preheater. The ammonia gas superheated by the superheater is supplied to a supply destination, and the discharge pressure of the pressure pump is not less than the required pressure required at the supply destination.

[0008] The heat transfer medium supply unit may adjust the flow rate of the heat transfer medium supplied to the superheater so that the temperature of the ammonia gas discharged from the superheater is equal to or greater than the required temperature at the supply destination, and the temperature of the ammonia gas discharged from the vaporizer is equal to or greater than the boiling point of liquid ammonia corresponding to the required pressure.

[0009] The heat transfer medium may be water vapor.

[0010] A compressor for pressurizing ammonia gas may be omitted between the superheater and the supply destination.

[0011] The heat transfer medium supply unit may include a first flow path connecting the heat transfer medium supply source and the superheater, a second flow path connecting the superheater and the vaporizer, a third flow path connecting the vaporizer and the preheater, and a first bypass flow path that bypasses the superheater and the first and second flow paths.

[0012] The heat transfer medium supply unit may include a first flow path connecting the heat transfer medium supply source and the superheater, a second flow path connecting the superheater and the vaporizer, a third flow path connecting the vaporizer and the preheater, and a second bypass flow path that bypasses the first and third flow paths by going around the superheater and the vaporizer.

[0013] The ammonia gas production apparatus described above may also include a gas-liquid separator installed between the vaporizer and the superheater, and a return unit that returns the liquid ammonia separated by the gas-liquid separator to the vaporizer.

[0014] The ammonia gas production apparatus described above may also include a gas-liquid separator installed between the vaporizer and the superheater, and a spray unit that atomizes the liquid ammonia separated by the gas-liquid separator and supplies it to the superheater.

[0015] To solve the above problems, a method for modifying a fuel gas consumption system according to one aspect of the present disclosure is a method for modifying a fuel gas consumption system comprising: a manufacturing apparatus that pressurizes a fuel including liquid fuel and / or fuel gas to produce high-pressure fuel gas; and a supply destination that utilizes the fuel gas produced by the manufacturing apparatus, wherein the manufacturing apparatus comprises: a booster pump that pressurizes liquid ammonia to a pressure higher than the required pressure required by the supply destination; a preheater that preheats the liquid ammonia by exchanging heat between the liquid ammonia pressurized by the booster pump and a heat transfer medium; a vaporizer that vaporizes the liquid ammonia by exchanging heat between the liquid ammonia preheated by the preheater and a heat transfer medium; a superheater that superheats the ammonia gas by exchanging heat between the ammonia gas vaporized by the vaporizer and a heat transfer medium; and a heat transfer medium supply unit that heats the heat transfer medium in the order of superheater, vaporizer, and preheater, and the ammonia gas superheated by the superheater is modified to be supplied to the supply destination.

[0016] According to this disclosure, it becomes possible to efficiently produce high-pressure ammonia gas.

[0017] Figure 1 is a schematic diagram of an ammonia gas production apparatus according to an embodiment of the present disclosure. Figure 2 is a schematic diagram of a conventional fuel gas consumption system. Figure 3 is a flowchart showing the processing flow of a modification method for the fuel gas production apparatus according to the same embodiment. Figure 4 is a schematic diagram of an ammonia gas production apparatus according to a first modified example. Figure 5 is a schematic diagram of an ammonia gas production apparatus according to a second modified example. Figure 6 is a schematic diagram of an ammonia gas production apparatus according to a third modified example. Figure 7 is a schematic diagram of an ammonia gas production apparatus according to a fourth modified example.

[0018] Embodiments of this disclosure will be described in detail below with reference to the attached drawings. The dimensions, materials, and other specific numerical values ​​shown in the embodiments are merely examples for the purpose of facilitating understanding and do not limit this disclosure unless otherwise specified. In this specification and in the drawings, elements having substantially the same function or configuration are denoted by the same reference numerals to avoid redundant explanations. Elements not directly related to this disclosure are omitted from the illustrations.

[0019] [1. Overview of the Ammonia Gas Production Apparatus] First, an overview of the ammonia gas production apparatus 100 according to the embodiment of this disclosure will be described with reference to Figure 1. Figure 1 is a schematic diagram of the ammonia gas production apparatus 100 according to the embodiment of this disclosure.

[0020] The ammonia gas production apparatus 100 according to this embodiment produces ammonia gas from liquid ammonia and supplies it to a supply destination 102. The supply destination 102 is, for example, a combustion device that uses ammonia gas as fuel, a boiler that includes a combustion device that uses ammonia gas as fuel, or a power generation device that includes a combustion device that uses ammonia gas as fuel.

[0021] As shown in Figure 1, the ammonia gas production apparatus 100 comprises a booster pump 110, a preheater 120, a vaporizer 130, a superheater 140, and a heat transfer medium supply unit 160. In Figure 1, the solid arrows indicate liquid ammonia (l_NH ３ ) and the flow of ammonia gas are shown. Also, in Figure 1, the dashed arrows indicate the flow of the heat transfer medium. In Figure 1, the dashed arrows indicate the flow of the signal.

[0022] The booster pump 110 pressurizes liquid ammonia. The booster pump 110 pressurizes liquid ammonia while it is still in a liquid state. The suction side of the booster pump 110 is connected to the liquid ammonia supply source 104. The liquid ammonia supply source 104 is, for example, a liquid ammonia tank. Note that liquid ammonia may contain other substances, or it may not contain other substances. Other substances may be, for example, water, hydrocarbons, etc. If liquid ammonia contains other substances, the ammonia content may be higher or lower than that of the other substances. The liquid ammonia tank may store ammonia water as liquid ammonia. The discharge side of the booster pump 110 is connected to the liquid ammonia inlet of the preheater 120 via piping 112.

[0023] The discharge pressure of the booster pump 110 is equal to or greater than the required pressure at the supply destination 102. The discharge pressure of the booster pump 110 is, for example, equal to or greater than the required pressure plus the pressure loss from the booster pump 110 to the supply destination 102. The required pressure is, for example, a pressure above atmospheric pressure, preferably 1 MPaG, and more preferably 4 MPaG. The upper limit of the discharge pressure of the booster pump 110 is determined according to the performance of the booster pump 110, for example, 10 MPaG.

[0024] The preheater 120 preheats the liquid ammonia by exchanging heat between the liquid ammonia, which has been pressurized by the booster pump 110, and the heat transfer medium. In this embodiment, the preheater 120 is an indirect heat exchanger. In this case, the preheater 120 exchanges heat between the liquid ammonia and the heat transfer medium supplied by the heat transfer medium supply unit 160, which will be described later. The preheater 120 transfers the heat contained in the heat transfer medium to the liquid ammonia.

[0025] The outlet of the liquid ammonia in the preheater 120 is connected to the inlet of the liquid ammonia in the vaporizer 130 via the piping 122. Therefore, the liquid ammonia preheated by the preheater 120 is supplied to the vaporizer 130 via the piping 122.

[0026] The vaporizer 130 vaporizes the liquid ammonia by exchanging heat between the preheated liquid ammonia and the heat transfer medium, which has been preheated by the preheater 120. In this embodiment, the vaporizer 130 is an indirect heat exchanger. In this case, the vaporizer 130 exchanges heat between the heat transfer medium supplied by the heat transfer medium supply unit 160 and the preheated liquid ammonia. The vaporizer 130 transfers the heat contained in the heat transfer medium to the liquid ammonia.

[0027] The ammonia gas outlet of the vaporizer 130 is connected to the ammonia gas inlet of the superheater 140 via piping 132. Therefore, the ammonia gas vaporized by the vaporizer 130 is supplied to the superheater 140 via piping 132.

[0028] The superheater 140 superheats the ammonia gas vaporized by the vaporizer 130 by exchanging heat with the heat transfer medium. The superheater 140 superheats the ammonia gas to a temperature above the required temperature at the supply destination 102, for example. The required temperature is, for example, 25°C, preferably 100°C, and more preferably 200°C. In this embodiment, the superheater 140 is an indirect heat exchanger. In this case, the superheater 140 exchanges heat between the heat transfer medium supplied by the heat transfer medium supply unit 160 and the ammonia gas. The superheater 140 transfers the heat contained in the heat transfer medium to the ammonia gas.

[0029] The ammonia gas superheated by the superheater 140 is supplied to the destination 102, for example, through a connecting pipe 150. The connecting pipe 150 connects the ammonia gas outlet of the superheater 140 to the destination 102.

[0030] Furthermore, in this embodiment, it is preferable that the ammonia gas production apparatus 100 does not include a compressor for pressurizing the ammonia gas between the superheater 140 and the supply destination 102.

[0031] The heat transfer medium supply unit 160 exchanges heat with the heat transfer medium in the order of superheater 140, vaporizer 130, and preheater 120. The heat transfer medium supply unit 160 adjusts the flow rate of the heat transfer medium supplied to the superheater 140 so that the temperature of the ammonia gas discharged from the superheater 140 is equal to or greater than the required temperature at the supply destination 102, and the temperature of the ammonia gas discharged from the vaporizer 130 is equal to or greater than the boiling point of liquid ammonia corresponding to the required pressure. The temperature of the heat transfer medium before it is supplied to the superheater 140 is above the required temperature. The heat transfer medium is, for example, water vapor, combustion exhaust gas, heated air, etc., and is preferably water vapor.

[0032] In this embodiment, the heat transfer medium supply unit 160 includes, for example, a first flow path 162, a second flow path 164, and a third flow path 166.

[0033] The first flow path 162 connects the heat transfer medium supply source 106 to the heat transfer medium inlet of the superheater 140. The heat transfer medium supply source 106 is, for example, a boiler. The boiler generates, for example, steam at a temperature exceeding the required temperature. The second flow path 164 connects the heat transfer medium outlet of the superheater 140 to the heat transfer medium inlet of the vaporizer 130. The third flow path 166 connects the heat transfer medium outlet of the vaporizer 130 to the heat transfer medium inlet of the preheater 120.

[0034] Furthermore, the ammonia gas production apparatus 100 may also include a flow sensor F, a flow rate adjustment mechanism 170, a first temperature sensor T1, a flow rate adjustment mechanism 180, and a control device 190.

[0035] The flow sensor F detects the flow rate of ammonia gas in the connecting pipe 150. The flow rate adjustment mechanism 170 is installed between the superheater 140 in the connecting pipe 150 and the measurement point of the flow sensor F. The flow rate adjustment mechanism 170 adjusts the flow rate of ammonia gas supplied from the connecting pipe 150 to the supply destination 102 by adjusting the opening of the flow path formed in the connecting pipe 150.

[0036] The first temperature sensor T1 detects the temperature inside the connecting pipe 150. The first temperature sensor T1 detects the temperature between the superheater 140 and the flow rate adjustment mechanism 170 in the connecting pipe 150. The temperature detected by the first temperature sensor T1 is approximately equal to the temperature of the ammonia gas discharged from the superheater 140. The flow rate adjustment mechanism 180 is provided in the first flow path 162 of the heat transfer medium supply unit 160. The flow rate adjustment mechanism 180 adjusts the flow rate of the heat transfer medium supplied from the first flow path 162 to the superheater 140 by adjusting the opening of the first flow path 162.

[0037] The control device 190 includes one or more processors 190a and one or more memories 190b connected to the processors 190a. The processors 190a include, for example, a CPU (Central Processing Unit). The memories 190b include, for example, ROM (Read Only Memory) and RAM (Random Access Memory). ROM is a memory element that stores programs and arithmetic parameters used by the CPU. RAM is a memory element that temporarily stores data such as variables and parameters used in processing performed by the CPU.

[0038] The processor 190a adjusts the opening of the flow rate adjustment mechanism 170 so that the flow rate detected by the flow rate sensor F becomes the required flow rate requested by the supply destination 102.

[0039] Furthermore, the processor 190a adjusts the opening of the flow rate adjustment mechanism 180 so that the temperature detected by the first temperature sensor T1 becomes the required temperature at the supply destination 102. In this embodiment, the processor 190a adjusts the opening of the flow rate adjustment mechanism 180 so that the temperature detected by the first temperature sensor T1 is maintained at the required temperature at the supply destination 102 without reducing the heat exchange efficiency. This adjusts the flow rate of the heat transfer medium supplied to the superheater 140.

[0040] Furthermore, the various processes, including the opening degree adjustment process of the flow rate adjustment mechanism 170 and the opening degree adjustment process of the flow rate adjustment mechanism 180, are executed by the processor 190a executing a program stored in memory 190b. However, the functions of the control device 190 may be divided among multiple devices, or multiple functions may be realized by a single device.

[0041] [2. Summary] As described above, the ammonia gas production apparatus 100 according to the present embodiment includes a booster pump 110 that boosts liquid ammonia, a preheater 120 that preheats the liquid ammonia by heat-exchanging the liquid ammonia boosted by the booster pump 110 with a heat medium, a vaporizer 130 that vaporizes the liquid ammonia by heat-exchanging the liquid ammonia preheated by the preheater 120 with the heat medium, a superheater 140 that superheats the ammonia gas by heat-exchanging the ammonia gas vaporized by the vaporizer 130 with the heat medium, and a heat medium supply unit 160 that heat-exchanges the heat medium in the order of the superheater 140, the vaporizer 130, and the preheater 120. The ammonia gas superheated by the superheater 140 is supplied to the supply destination 102, and the discharge pressure of the booster pump 110 is not less than the required pressure required at the supply destination 102.

[0042] Therefore, the ammonia gas production apparatus 100 according to the present embodiment can efficiently boost ammonia gas. Further, the ammonia gas production apparatus 100 according to the present embodiment does not need to include a compressor that compresses ammonia gas to the required pressure between the superheater 140 and the supply destination 102, or the compressor can be miniaturized. Therefore, the ammonia gas production apparatus 100 according to the present embodiment can reduce the power consumption of the compressor. The power consumption of a compressor that compresses gas is much larger than the power consumption of a booster pump that boosts liquid. Therefore, the ammonia gas production apparatus 100 according to the present embodiment can produce ammonia gas at a low cost as compared with an ammonia gas production apparatus including a compressor. Further, the ammonia gas production apparatus 100 according to the present embodiment can improve the energy efficiency of the entire system including the ammonia gas production apparatus 100.

[0043] The heat medium supply unit 160 may adjust the supply flow rate of the heat medium to the superheater 140 so that the temperature of the ammonia gas sent out from the superheater 140 is not less than the required temperature required at the supply destination 102, and the temperature of the ammonia gas sent out from the vaporizer 130 is not less than the boiling point of the liquid ammonia corresponding to the required pressure.

[0044] As a result, the ammonia gas production apparatus 100 according to the present embodiment can produce ammonia gas that satisfies both the required pressure and the required temperature required by the supply destination 102.

[0045] The heat medium may be steam.

[0046] The heat capacity of steam is larger than the heat capacity of combustion exhaust gas and the heat capacity of air. Therefore, the ammonia gas production apparatus 100 according to the present embodiment can preheat liquid ammonia more efficiently in the preheater 120 than when using combustion exhaust gas or air as the heat medium. Further, the ammonia gas production apparatus 100 according to the present embodiment can vaporize liquid ammonia more efficiently in the vaporizer 130 than when using combustion exhaust gas or air as the heat medium. Further, the ammonia gas production apparatus 100 according to the present embodiment can superheat ammonia gas more efficiently in the superheater 140 than when using combustion exhaust gas or air as the heat medium.

[0047] [3. Manufacturing Method of Ammonia Gas Production Apparatus] When the above ammonia gas production apparatus 100 is newly manufactured, the supply source 104 of liquid ammonia is connected to the suction side of the booster pump 110. Further, the discharge side of the booster pump 110 and the inlet of liquid ammonia of the preheater 120 are connected by a pipe 112. The outlet of liquid ammonia of the preheater 120 and the inlet of liquid ammonia of the vaporizer 130 are connected by a pipe 122. The outlet of ammonia gas of the vaporizer 130 and the inlet of ammonia gas of the superheater 140 are connected by a pipe 132. The outlet of ammonia gas of the superheater 140 and the supply destination 102 are connected by a communication pipe 150. Note that a first temperature sensor T1, a flow rate adjustment mechanism 170, and a flow rate sensor F may be provided in the flow rate adjustment mechanism 170.

[0048] Furthermore, the heat transfer medium supply source 106 and the heat transfer medium inlet of the superheater 140 are connected by a first flow path 162. The heat transfer medium outlet of the superheater 140 and the heat transfer medium inlet of the vaporizer 130 are connected by a second flow path 164. The heat transfer medium outlet of the vaporizer 130 and the heat transfer medium inlet of the preheater 120 are connected by a third flow path 166. A flow rate adjustment mechanism 180 may be provided in the first flow path 162.

[0049] [4. Method for Modifying the Fuel Gas Consumption System] As described above, the ammonia gas production apparatus 100 can be newly manufactured, or the conventional fuel gas consumption system 10 can be modified into the ammonia gas production apparatus 100. The method for modifying the fuel gas consumption system 10 according to this embodiment will be explained with reference to Figures 2 and 3. Figure 2 is a schematic diagram of a conventional fuel gas consumption system 10. Figure 3 is a flowchart showing the processing flow of the modification method for the fuel gas consumption system 10 according to this embodiment.

[0050] In the modification method according to this embodiment, the conventional fuel gas consumption system 10 is modified into the ammonia gas production apparatus 100 according to this embodiment.

[0051] As shown in Figure 2, the conventional fuel gas consumption system 10 comprises a manufacturing device 20 and a supply destination 102. The manufacturing device 20 pressurizes a fuel containing liquid fuel and / or fuel gas to produce high-pressure fuel gas. The liquid fuel is, for example, liquefied fossil fuel such as liquefied natural gas (LNG), or liquid ammonia. As described above, liquid ammonia may contain other substances, or it may contain other substances. If liquid ammonia contains other substances, the ammonia content may be higher or lower than that of the other substances. The liquid fuel may also be ammonia water. The fuel gas is, for example, fossil fuel gas such as natural gas, or ammonia gas. As described above, ammonia gas may contain other substances, or it may contain other substances. If ammonia gas contains other substances, the ammonia content may be higher or lower than that of the other substances. Ammonia gas may also be a gas obtained by vaporizing ammonia water. In a conventional fuel gas consumption system 10, the recipient 102 utilizes fuel gas produced by the manufacturing device 20.

[0052] For example, as shown in Figure 2, the manufacturing apparatus 20 comprises one or more first booster pumps 22, one or more heat exchangers 24, a compressor 26, and connecting pipes 30, 32, and 34. Components that are substantially the same as those in the ammonia gas manufacturing apparatus 100 described above are denoted by the same reference numerals and their descriptions are omitted. In addition, the conventional fuel gas consumption system 10 may also include a heat transfer medium supply unit 160.

[0053] The first booster pump 22 pressurizes fuel, including liquid fuel and / or fuel gas. The rated discharge pressure of the first booster pump 22 is lower than the rated discharge pressure of the booster pump 110. The first booster pump 22 pressurizes liquid fuel while it remains in a liquid state, for example. The suction side of the first booster pump 22 is connected to the liquid fuel supply source 40. The discharge side of the first booster pump 22 is connected to the fuel inlet of the heat exchanger 24 through the connecting pipe 30.

[0054] The heat exchanger 24 heats the fuel by exchanging heat between the fuel, which has been pressurized by the first booster pump 22, and the heat transfer medium.

[0055] The connecting pipe 32 connects the heat exchanger 24 and the compressor 26. More specifically, the connecting pipe 32 connects the fuel gas outlet of the heat exchanger 24 to the suction side of the compressor 26. Therefore, the fuel gas heated by the heat exchanger 24 is supplied to the compressor 26 through the connecting pipe 32.

[0056] The compressor 26 pressurizes the fuel gas, which has been superheated by the heat exchanger 24, and supplies it to the destination 102. For example, the compressor 26 pressurizes the fuel gas to a pressure higher than the required pressure at the destination 102.

[0057] The connecting pipe 34 connects the compressor 26 to the supply destination 102. More specifically, the connecting pipe 34 connects the discharge side of the compressor 26 to the supply destination 102. Therefore, the fuel gas pressurized by the compressor 26 is supplied to the supply destination 102 through the connecting pipe 34.

[0058] Next, a method for modifying the fuel gas consumption system 10 according to this embodiment will be described. The method for modifying the fuel gas consumption system 10 according to this embodiment involves modifying the manufacturing apparatus 20 into the ammonia gas manufacturing apparatus 100 described above. For example, as shown in Figure 3, in step S110, first, the compressor 26 and connecting pipes 32 and 34 are removed from the fuel gas consumption system 10.

[0059] Then, in step S120, the fuel gas outlet of the heat exchanger 24 or superheater 140 is connected to the supply destination 102 by the connecting pipe 150. For example, in a conventional fuel gas consumption system 10, if a heat exchanger 24 corresponding to a preheater 120, a heat exchanger 24 corresponding to a vaporizer 130, and a heat exchanger 24 corresponding to a superheater 140 are provided, the fuel gas outlet of the last stage heat exchanger 24 corresponding to the superheater 140 is connected to the supply destination 102 by the connecting pipe 150.

[0060] On the other hand, in a conventional fuel gas consumption system 10, if there is no heat exchanger 24 corresponding to the preheater 120, but there is a heat exchanger 24 corresponding to the vaporizer 130 and a heat exchanger 24 corresponding to the superheater 140, then the preheater 120 is added before the heat exchanger 24 corresponding to the vaporizer 130. Then, the fuel gas outlet of the last heat exchanger 24 corresponding to the superheater 140 and the supply destination 102 are connected by a connecting pipe 150.

[0061] Furthermore, in a conventional fuel gas consumption system 10, if a heat exchanger 24 corresponding to the vaporizer 130 is not provided, but a heat exchanger 24 corresponding to the preheater 120 and a heat exchanger 24 corresponding to the superheater 140 are provided, a vaporizer 130 is added between the heat exchanger 24 corresponding to the preheater 120 and the heat exchanger 24 corresponding to the superheater 140. The fuel gas outlet of the last stage heat exchanger 24 corresponding to the superheater 140 and the supply destination 102 are connected by a connecting pipe 150.

[0062] Furthermore, in a conventional fuel gas consumption system 10, if a heat exchanger 24 corresponding to the superheater 140 is not provided, but a heat exchanger 24 corresponding to the preheater 120 and a heat exchanger 24 corresponding to the vaporizer 130 are provided, then a superheater 140 is added downstream of the heat exchanger 24 corresponding to the vaporizer 130. The fuel gas outlet of the superheater 140 and the supply destination 102 are connected by a connecting pipe 150.

[0063] Furthermore, if all the heat exchangers 24 in the conventional fuel gas consumption system 10 do not function as preheaters 120, vaporizers 130, and superheaters 140, all the heat exchangers 24 are replaced with preheaters 120, vaporizers 130, and superheaters 140. The fuel gas outlet of the superheater 140 and the supply destination 102 are then connected by a connecting pipe 150.

[0064] Next, in step S130, the first booster pump 22 is replaced with a second booster pump that is driven at a discharge pressure equal to or greater than the required pressure at the supply destination 102. For example, the first booster pump 22 is replaced with a booster pump 110. However, if the rated discharge pressure of the first booster pump 22 is equal to or greater than the required pressure, the first booster pump 22 may not be replaced with the booster pump 110 after the compressor 26 is removed, and the discharge pressure of the first booster pump 22 may be set to equal or greater than the required pressure. In addition, a liquid ammonia supply source 104 is connected to the suction side of the second booster pump (booster pump 110).

[0065] As described above, the modification method for the fuel gas consumption system 10 according to this embodiment is a modification method for the fuel gas consumption system 10 comprising a manufacturing device 20 that pressurizes a fuel including liquid fuel and / or fuel gas to produce high-pressure fuel gas, and a supply destination 102 that utilizes the fuel gas produced by the manufacturing device 20, wherein the manufacturing device 20 comprises a booster pump 110 that pressurizes liquid ammonia to a pressure higher than the required pressure required at the supply destination, and a heat transfer medium that exchanges heat between the liquid ammonia pressurized by the booster pump 110 and the liquid ammonia The ammonia production apparatus 100 comprises a preheater 120 for preheating liquid ammonia, a vaporizer 130 for vaporizing liquid ammonia by exchanging heat between the liquid ammonia preheated by the preheater 120 and a heat transfer medium, a superheater 140 for superheating the ammonia gas by exchanging heat between the ammonia gas vaporized by the vaporizer 130 and a heat transfer medium, and a heat transfer medium supply unit 160 for heat exchange of the heat transfer medium in the order of superheater 140, vaporizer 130, and preheater 120, and the ammonia gas superheated by the superheater 140 is supplied to the supply destination 102.

[0066] As a result, the modification method for the fuel gas consumption system 10 according to this embodiment allows the conventional manufacturing apparatus 20 to be modified into an ammonia gas manufacturing apparatus 100 that does not have a compressor 26.

[0067] In this example, a conventional manufacturing apparatus 20 is given that includes a first booster pump 22, a heat exchanger 24, and a compressor 26. However, the configuration of the conventional manufacturing apparatus 20 is not limited as long as it can boost a fuel containing liquid fuel and / or fuel gas to produce high-pressure fuel gas. For example, the conventional manufacturing apparatus 20 may not include the first booster pump 22 but include a compressor 26, or it may not include a compressor 26 but include the first booster pump 22. Furthermore, the conventional manufacturing apparatus 20 may include multiple first booster pumps 22 or multiple compressors 26.

[0068] Furthermore, the conventional manufacturing apparatus 20 does not need to be equipped with a heat exchanger 24. In this case, the modification method for the fuel gas consumption system 10 may include one or more preheaters 120, one or more vaporizers 130, and one or more superheaters 140. Also, if the conventional manufacturing apparatus 20 is equipped with one or more heat exchangers 24, one or more heat exchangers that function as preheaters 120, vaporizers 130, and / or superheaters 140 may be added. In this case, some of the heat exchangers 24 may be replaced with one or more heat exchangers 24 that function as preheaters 120, vaporizers 130, and / or superheaters 140.

[0069] [5. Modified Examples] [5.1 First Modified Example] Figure 4 is a schematic diagram of an ammonia gas production apparatus 200 according to the first modified example. As shown in Figure 4, the ammonia gas production apparatus 200 according to the first modified example includes a booster pump 110, a preheater 120, a vaporizer 130, a superheater 140, a connecting pipe 150, and a heat transfer medium supply unit 210. The ammonia gas production apparatus 200 may also include a flow sensor F, a flow rate adjustment mechanism 170, a first temperature sensor T1, a flow rate adjustment mechanism 180, a second temperature sensor T2, a flow rate adjustment mechanism 220, and a control device 190. In Figure 4, the solid arrows indicate liquid ammonia (l_NH ３Figure 4 shows the flow of the heat transfer medium and ammonia gas. In Figure 4, the dashed arrows indicate the flow of the heat transfer medium. In Figure 4, the dotted arrows indicate the flow of the signal. Components that are substantially the same as those in the ammonia gas production apparatus 100 described above are given the same reference numerals and their descriptions are omitted.

[0070] The heat transfer medium supply unit 210 includes a first flow path 162, a second flow path 164, and a third flow path 166, as well as a first bypass flow path 212. The first bypass flow path 212 bypasses the superheater 140 and bypasses the first flow path 162 and the second flow path 164.

[0071] The second temperature sensor T2 detects the temperature inside the piping 132. The flow rate adjustment mechanism 220 is provided in the first bypass flow path 212 of the heat transfer medium supply unit 210. The flow rate adjustment mechanism 220 adjusts the flow rate of the heat transfer medium supplied from the first flow path 162 to the vaporizer 130, bypassing the superheater 140, by adjusting the opening of the first bypass flow path 212.

[0072] In the first modified example, the processor 190a of the control device 190 adjusts the opening of the flow rate adjustment mechanism 220 so that the temperature detected by the second temperature sensor T2 is at a temperature that can reliably vaporize liquid ammonia into ammonia gas in the vaporizer 130. For example, if the temperature of the heat transfer medium supplied to the vaporizer 130 drops to a level that prevents liquid ammonia from vaporizing in the vaporizer 130 due to heat exchange with ammonia gas in the superheater 140, the processor 190a adjusts the opening of the flow rate adjustment mechanism 220 so that the temperature detected by the second temperature sensor T2 is above the boiling point of ammonia. This adjusts the flow rate of the heat transfer medium supplied to the vaporizer 130.

[0073] As described above, the heat transfer medium supply unit 210 according to the first modified example includes a first flow path 162 connecting the heat transfer medium supply source 106 and the superheater 140, a second flow path 164 connecting the superheater 140 and the vaporizer 130, a third flow path 166 connecting the vaporizer 130 and the preheater 120, and a first bypass flow path 212 that bypasses the superheater 140 and bypasses the first flow path 162 and the second flow path 164.

[0074] The vaporizer 130 requires latent heat to vaporize liquid ammonia, and therefore consumes more thermal energy than the preheater 120 and superheater 140. The heat transfer medium supply unit 210 according to the first modified example can directly supply the high-temperature heat transfer medium supplied from the heat transfer medium supply source 106 to the vaporizer 130. Therefore, the heat transfer medium supply unit 210 according to the first modified example can efficiently vaporize liquid ammonia in the vaporizer 130 even if the temperature of the heat transfer medium in the superheater 140 drops due to fluctuations in the supply amount of liquid ammonia or the supply amount of heat transfer medium.

[0075] [5.2 Second Modification] Figure 5 is a schematic diagram of an ammonia gas production apparatus 300 according to the second modification. As shown in Figure 5, the ammonia gas production apparatus 300 according to the second modification includes a booster pump 110, a preheater 120, a vaporizer 130, a superheater 140, a connecting pipe 150, and a heat transfer medium supply unit 310. The ammonia gas production apparatus 300 may also include a flow sensor F, a flow rate adjustment mechanism 170, a first temperature sensor T1, a flow rate adjustment mechanism 180, a second temperature sensor T2, a flow rate adjustment mechanism 320, and a control device 190. In Figure 5, the solid arrows indicate liquid ammonia (l_NH ３ Figure 5 shows the flow of the heat transfer medium and ammonia gas. In Figure 5, the dashed arrows indicate the flow of the heat transfer medium. In Figure 5, the dotted arrows indicate the flow of the signal. Components that are substantially the same as those in the ammonia gas production apparatus 100 and ammonia gas production apparatus 200 are given the same reference numerals and their descriptions are omitted.

[0076] The heat transfer medium supply unit 310 includes a first flow path 162, a second flow path 164, and a third flow path 166, as well as a second bypass flow path 312. The second bypass flow path 312 bypasses the first flow path 162 and the third flow path 166, bypassing the superheater 140 and the vaporizer 130.

[0077] The flow rate adjustment mechanism 320 is provided in the second bypass flow path 312 of the heat transfer medium supply unit 310. The flow rate adjustment mechanism 320 adjusts the flow rate of the heat transfer medium supplied from the first flow path 162 to the preheater 120, bypassing the superheater 140 and vaporizer 130, by adjusting the opening of the second bypass flow path 312.

[0078] In the second modified example, the processor 190a of the control device 190 adjusts the opening of the flow rate adjustment mechanism 320 so that the temperature detected by the second temperature sensor T2 is at a temperature that can reliably vaporize liquid ammonia into ammonia gas in the vaporizer 130. For example, if the temperature of the heat transfer medium supplied to the preheater 120 drops to a level that prevents the preheater 120 from adequately preheating the liquid ammonia due to the vaporization of liquid ammonia in the vaporizer 130, the processor 190a adjusts the opening of the flow rate adjustment mechanism 320 so that the temperature detected by the second temperature sensor T2 is above the boiling point of ammonia. This adjusts the flow rate of the heat transfer medium supplied to the preheater 120.

[0079] As described above, the heat transfer medium supply unit 310 according to the second modified example includes a first flow path 162 connecting the heat transfer medium supply source 106 and the superheater 140, a second flow path 164 connecting the superheater 140 and the vaporizer 130, a third flow path 166 connecting the vaporizer 130 and the preheater 120, and a second bypass flow path 312 that bypasses the first flow path 162 and the third flow path 166 by going around the superheater 140 and the vaporizer 130.

[0080] The vaporizer 130 requires latent heat to vaporize liquid ammonia, and therefore consumes more thermal energy than the preheater 120 and superheater 140. The heat transfer medium supply unit 310 according to the second modification can directly supply the high-temperature heat transfer medium supplied from the heat transfer medium supply source 106 to the preheater 120. Therefore, the heat transfer medium supply unit 310 according to the second modification can sufficiently preheat the liquid ammonia in the preheater 120 even if the temperature of the heat transfer medium in the vaporizer 130 drops due to fluctuations in the supply amount of liquid ammonia or the supply amount of heat transfer medium. Consequently, the heat transfer medium supply unit 310 according to the second modification can efficiently vaporize liquid ammonia in the vaporizer 130.

[0081] [5.3 Third Modification] Figure 6 is a schematic diagram of the ammonia gas production apparatus 400 according to the third modification. As shown in Figure 6, the ammonia gas production apparatus 400 according to the third modification includes a booster pump 110, a preheater 120, a vaporizer 130, a superheater 140, a connecting pipe 150, a heat transfer medium supply unit 160, a gas-liquid separator 410, and a return unit 420. The ammonia gas production apparatus 400 may further include a flow sensor F, a flow rate adjustment mechanism 170, a first temperature sensor T1, a flow rate adjustment mechanism 180, and a control device 190. In Figure 6, the solid arrows indicate liquid ammonia (l_NH ３ ) and the flow of ammonia gas are shown. In Figure 6, the dashed arrows indicate the flow of the heat transfer medium. In Figure 6, the dashed arrows indicate the flow of the signal. Components that are substantially the same as those in the ammonia gas production apparatus 100 described above are given the same reference numerals and their descriptions are omitted.

[0082] The gas-liquid separator 410 is installed between the vaporizer 130 and the superheater 140. In a third modified example, the gas-liquid separator 410 is installed, for example, in the piping 132 connecting the ammonia gas outlet of the vaporizer 130 and the ammonia gas inlet of the superheater 140. The gas-liquid separator 410 separates the gas-liquid mixture of liquid ammonia and ammonia gas discharged from the vaporizer 130. The ammonia gas from which the liquid ammonia has been removed by the gas-liquid separator 410 is then supplied to the superheater 140.

[0083] The return unit 420 returns the liquid ammonia separated by the gas-liquid separator 410 to the vaporizer 130. The return unit 420 is, for example, a pump. The suction side of the return unit 420 is connected to the gas-liquid separator 410. The discharge side of the return unit 420 is connected to the ammonia gas inlet of the vaporizer 130 through the piping 122.

[0084] As described above, the ammonia gas production apparatus 400 according to the third modified example includes a gas-liquid separator 410 provided between the vaporizer 130 and the superheater 140, and a return unit 420 that returns the liquid ammonia separated by the gas-liquid separator 410 to the vaporizer 130.

[0085] Fluctuations in the discharge flow rate of the booster pump 110, and / or fluctuations in the supply flow rate of the heat transfer medium by the heat transfer medium supply unit 160, can sometimes prevent the liquid ammonia from being sufficiently vaporized in the vaporizer 130. Therefore, the ammonia gas production apparatus 400 according to the third modification is equipped with a gas-liquid separator 410, which prevents the supply of liquid ammonia to the superheater 140. As a result, the ammonia gas production apparatus 400 according to the third modification can stably supply ammonia gas that meets the required pressure and temperature to the supply destination 102. Furthermore, the ammonia gas production apparatus 400 according to the third modification is equipped with a return unit 420, which allows the liquid ammonia separated by the gas-liquid separator 410 to be vaporized in the vaporizer 130.

[0086] [5.4 Fourth Modification] Figure 7 is a schematic diagram of the ammonia gas production apparatus 500 according to the fourth modification. As shown in Figure 7, the ammonia gas production apparatus 500 according to the fourth modification includes a booster pump 110, a preheater 120, a vaporizer 130, a superheater 140, a connecting pipe 150, a heat transfer medium supply unit 160, a gas-liquid separator 410, and a spray unit 510. The ammonia gas production apparatus 500 may further include a flow sensor F, a flow rate adjustment mechanism 170, a first temperature sensor T1, a flow rate adjustment mechanism 180, and a control device 190. In Figure 7, the solid arrows indicate liquid ammonia (l_NH ３Figure 7 shows the flow of the heat transfer medium and ammonia gas. In Figure 7, the dashed arrows indicate the flow of the heat transfer medium. In Figure 7, the dotted arrows indicate the flow of the signal. Components that are substantially the same as those in the ammonia gas production apparatus 100 and ammonia gas production apparatus 400 are given the same reference numerals and their descriptions are omitted.

[0087] The spray unit 510 atomizes the liquid ammonia separated by the gas-liquid separator 410 and supplies it to the superheater 140. In a fourth modified example, the spray unit 510 includes, for example, a two-fluid nozzle. The spray unit 510 atomizes the liquid ammonia using, for example, the ammonia gas separated by the gas-liquid separator 410.

[0088] As described above, the ammonia gas production apparatus 500 according to the fourth modified example includes a gas-liquid separator 410 provided between the vaporizer 130 and the superheater 140, and a spray unit 510 that atomizes the liquid ammonia separated by the gas-liquid separator 410 and supplies it to the superheater 140.

[0089] Fluctuations in the discharge flow rate of the booster pump 110 and / or fluctuations in the supply flow rate of the heat transfer medium by the heat transfer medium supply unit 160 can cause insufficient vaporization of liquid ammonia in the vaporizer 130. Therefore, the ammonia gas production apparatus 500 according to the fourth modification is equipped with a gas-liquid separator 410 and a spray unit 510, which allows liquid ammonia to be vaporized in the superheater 140. Specifically, the spray unit 510 atomizes the liquid ammonia before supplying it to the superheater 140, thereby increasing the specific surface area of ​​the liquid ammonia in the superheater 140 compared to supplying the liquid ammonia directly without atomization. Consequently, the ammonia gas production apparatus 500 according to the fourth modification is able to efficiently transfer heat from the heat transfer medium to the liquid ammonia in the superheater 140. For this reason, the ammonia gas production apparatus 500 according to the fourth modification is able to vaporize liquid ammonia in the superheater 140. As a result, the ammonia gas production apparatus 500 according to the fourth modified example can stably supply ammonia gas that meets the required pressure and temperature to the recipient 102.

[0090] While embodiments have been described above with reference to the attached drawings, it goes without saying that this disclosure is not limited to the embodiments described above. It will be obvious to those skilled in the art that various modifications or alterations can be conceived within the scope of the claims, and these will naturally also fall within the technical scope of this disclosure.

[0091] For example, in the above embodiments and the first to fourth modifications, the ammonia gas production apparatus 100, 200, 300, 400, and 500 are shown as having one vaporizer 130. However, the ammonia gas production apparatus 100, 200, 300, 400, and 500 may also have multiple vaporizers 130 arranged in parallel. In this case, it is preferable to provide an on-off valve at the liquid ammonia inlet of the vaporizer 130. In this case, the on-off valve is opened or closed according to fluctuations in the supply flow rate of liquid ammonia supplied from the preheater 120 to the vaporizer 130. For example, if the supply flow rate of liquid ammonia supplied from the preheater 120 to the vaporizer 130 is high, the number of vaporizers 130 for which the on-off valve is opened is increased. If the supply flow rate of liquid ammonia supplied from the preheater 120 to the vaporizer 130 is low, the number of vaporizers 130 for which the on-off valve is opened is decreased.

[0092] Furthermore, in the above embodiments and the first to fourth modifications, the ammonia gas production apparatus 100, 200, 300, 400, and 500 may further include bypass piping that directly connects the piping 112 to the supply destination 102, or directly connects the piping 112 to the connecting pipe 150.

[0093] Alternatively, an ammonia gas production apparatus may be provided that includes a booster pump 110 for increasing the pressure of liquid ammonia, a preheater 120 for preheating the liquid ammonia by exchanging heat between the liquid ammonia pressurized by the booster pump 110 and a heat transfer medium, a vaporizer 130 for vaporizing the liquid ammonia by exchanging heat between the liquid ammonia preheated by the preheater 120 and a heat transfer medium, a superheater 140 for superheating the ammonia gas by exchanging heat between the ammonia gas vaporized by the vaporizer 130 and a heat transfer medium, and a heat transfer medium supply unit 160 for heat exchange of the heat transfer medium in the order of superheater 140, vaporizer 130, and preheater 120, wherein the ammonia gas superheated by the superheater 140 is supplied to the supply destination 102, and the heat transfer medium is water vapor. In this ammonia gas production apparatus, the preheater 120 can preheat liquid ammonia more efficiently than when combustion exhaust gas or air is used as the heat transfer medium. Furthermore, the ammonia gas production apparatus can vaporize liquid ammonia more efficiently in the vaporizer 130 than when combustion exhaust gas or air is used as the heat transfer medium. Also, the ammonia gas production apparatus can superheat the ammonia gas more efficiently in the superheater 140 than when combustion exhaust gas or air is used as the heat transfer medium.

[0094] Furthermore, in the above embodiments and the first to fourth modifications, examples have been described in which the heat transfer medium is water vapor, combustion exhaust gas, heated air, etc. However, the heat transfer medium may be a fluid other than these. For example, the heat transfer medium may be seawater, industrial water, tap water, outside air, etc. With this configuration, the temperature of ammonia can be suitably raised in one or more of the preheater 120, vaporizer 130, and superheater 140.

[0095] Furthermore, ammonia gas production apparatuses 100, 200, 300, 400, and 500 may further include an intermediate heat exchanger for heat exchange between a fluid and a heat transfer medium, and the heat transfer medium that has undergone heat exchange by the intermediate heat exchanger may be sent to one or more of the preheater 120, vaporizer 130, and superheater 140. For example, when a highly corrosive fluid such as seawater is used as the fluid, and a less corrosive heat transfer medium such as industrial water is used as the heat transfer medium, the scope of corrosion countermeasures can be reduced by providing an intermediate heat exchanger.

[0096] This disclosure can contribute, for example, to Sustainable Development Goal 7, "Ensure access to affordable, reliable, sustainable and modern energy," and Goal 13, "Take urgent action to combat climate change and its impacts."

[0097] 10: Fuel gas consumption system 20: Manufacturing equipment 100: Ammonia gas manufacturing equipment 102: Supply destination 110: Booster pump (second booster pump) 130: Vaporizer 140: Superheater 150: Connecting pipe 160: Heat transfer medium supply section 162: First flow path 164: Second flow path 166: Third flow path 200: Ammonia gas manufacturing equipment 210: Heat transfer medium supply section 212: First bypass flow path 300: Ammonia gas manufacturing equipment 312: Second bypass flow path 400: Ammonia gas manufacturing equipment 410: Gas-liquid separator 420: Return section 500: Ammonia gas manufacturing equipment 510: Spray section

Claims

1. An ammonia gas production apparatus comprising: a booster pump for increasing the pressure of liquid ammonia; a preheater for preheating the liquid ammonia by exchanging heat between the liquid ammonia pressurized by the booster pump and a heat transfer medium; a vaporizer for vaporizing the liquid ammonia by exchanging heat between the liquid ammonia preheated by the preheater and the heat transfer medium; a superheater for superheating the ammonia gas by exchanging heat between the ammonia gas vaporized by the vaporizer and the heat transfer medium; and a heat transfer medium supply unit for heat exchange of the heat transfer medium in the order of the superheater, the vaporizer, and the preheater, wherein the ammonia gas superheated by the superheater is supplied to a destination, and the discharge pressure of the booster pump is equal to or greater than the required pressure at the destination.

2. The ammonia gas production apparatus according to claim 1, wherein the heat transfer medium supply unit adjusts the flow rate of the heat transfer medium supplied to the superheater such that the temperature of the ammonia gas discharged from the superheater is equal to or greater than the required temperature at the supply destination, and the temperature of the ammonia gas discharged from the vaporizer is equal to or greater than the boiling point of the liquid ammonia corresponding to the required pressure.

3. The ammonia gas production apparatus according to claim 1 or 2, wherein the heat transfer medium is water vapor.

4. The ammonia gas production apparatus according to claim 1 or 2, wherein a compressor for pressurizing the ammonia gas is not provided between the superheater and the supply destination.

5. The ammonia gas production apparatus according to claim 1 or 2, wherein the heat transfer medium supply unit comprises: a first flow path connecting the heat transfer medium supply source and the superheater; a second flow path connecting the superheater and the vaporizer; a third flow path connecting the vaporizer and the preheater; and a first bypass flow path that bypasses the superheater and the first and second flow paths.

6. The ammonia gas production apparatus according to claim 1 or 2, wherein the heat transfer medium supply unit comprises: a first flow path connecting the heat transfer medium supply source and the superheater; a second flow path connecting the superheater and the vaporizer; a third flow path connecting the vaporizer and the preheater; and a second bypass flow path that bypasses the first flow path and the third flow path, bypassing the superheater and the vaporizer.

7. An ammonia gas production apparatus according to claim 1 or 2, comprising: a gas-liquid separator provided between the vaporizer and the superheater; and a return unit for returning the liquid ammonia separated by the gas-liquid separator to the vaporizer.

8. An ammonia gas production apparatus according to claim 1 or 2, comprising: a gas-liquid separator provided between the vaporizer and the superheater; and a spray unit that atomizes the liquid ammonia separated by the gas-liquid separator and supplies it to the superheater.

9. A method for modifying a fuel gas consumption system comprising: a manufacturing apparatus for pressurizing a fuel including a liquid fuel and / or fuel gas to produce high-pressure fuel gas; and a supply destination that utilizes the fuel gas produced by the manufacturing apparatus, the method comprising modifying the manufacturing apparatus to an ammonia gas production apparatus that supplies the ammonia gas superheated by the superheater to the supply destination, the manufacturing apparatus comprising: a booster pump for pressurizing liquid ammonia to a pressure higher than the required pressure required by the supply destination; a preheater for preheating the liquid ammonia by exchanging heat between the liquid ammonia pressurized by the booster pump and a heat transfer medium; a vaporizer for vaporizing the liquid ammonia by exchanging heat between the liquid ammonia preheated by the preheater and the heat transfer medium; a superheater for superheating the ammonia gas by exchanging heat between the ammonia gas vaporized by the vaporizer and the heat transfer medium; and a heat transfer medium supply unit for heat exchange of the heat transfer medium in the order of the superheater, the vaporizer, and the preheater.

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