An ammonia synthesis system and an ammonia synthesis control method

Abstract

The application provides an ammonia synthesis system and an ammonia synthesis control method. An ammonia synthesis unit in the ammonia synthesis system performs an ammonia synthesis operation. A heat storage device in the ammonia synthesis system stores excess heat generated by the ammonia synthesis unit when the ammonia synthesis unit performs the ammonia synthesis operation in a case where a current operating power of the ammonia synthesis system is greater than or equal to a preset first threshold value. The stored heat is used to supply heat for the ammonia synthesis system in a case where the current operating power of the ammonia synthesis system is less than the first threshold value. The heat balance of the ammonia synthesis system at low power is satisfied, so that the ammonia synthesis system can work normally, and the reliability of the ammonia synthesis system is improved.

Description

Technical Field

[0001] This invention relates to the field of ammonia synthesis, and more specifically, to an ammonia synthesis system and ammonia synthesis control method. Background Technology

[0002] Currently, hydrogen can be used as a raw material for ammonia synthesis, but the ammonia synthesis process requires a large amount of hydrogen. Currently, hydrogen production is mostly achieved through fossil fuel-based methods, but this method is not environmentally friendly and consumes a significant amount of energy.

[0003] To produce hydrogen in an environmentally friendly way, renewable energy sources such as wind and solar power can be used. However, renewable energy sources are affected by weather, and hydrogen production is unstable. When hydrogen production is low, the ammonia synthesis system operates at low power, and the heat generated cannot meet its own operating needs. Consequently, the ammonia synthesis system cannot work properly, reducing its reliability. Summary of the Invention

[0004] In view of this, the present invention provides an ammonia synthesis system and an ammonia synthesis control method to solve the problem that when the hydrogen production is low, the ammonia synthesis system operates at low power, the heat generated cannot meet its own operating requirements, and thus the ammonia synthesis system cannot work properly, resulting in low reliability of the ammonia synthesis system.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] An ammonia synthesis system, comprising:

[0007] Thermal storage equipment and at least one ammonia synthesis unit;

[0008] The ammonia synthesis unit is used to perform ammonia synthesis operations;

[0009] The heat storage device is used to store at least the excess heat generated by the ammonia synthesis unit during the ammonia synthesis operation when the current operating power of the ammonia synthesis system is greater than or equal to a preset first threshold; and to use the stored heat to heat the ammonia synthesis system when the current operating power of the ammonia synthesis system is less than the first threshold.

[0010] Optionally, in the aforementioned ammonia synthesis system, the ammonia synthesis unit may be at least two.

[0011] The heat storage device supplies heat to the first ammonia synthesis unit in each of the ammonia synthesis units;

[0012] The heat storage device stores the excess heat generated by the second ammonia synthesis unit during the ammonia synthesis operation. The second ammonia synthesis unit is the unit other than the first ammonia synthesis unit among all the ammonia synthesis units.

[0013] Optionally, in the aforementioned ammonia synthesis system, the operating power of the first ammonia synthesis unit is less than a preset second threshold; the operating power of the second ammonia synthesis unit is greater than or equal to the second threshold.

[0014] Optionally, each of the ammonia synthesis units in the aforementioned ammonia synthesis system includes: an ammonia synthesis compression device and an ammonia synthesis device;

[0015] The output end of the ammonia synthesis compression device in the first ammonia synthesis unit is connected to the input end of the heating channel in the heat storage device, and the output end of the heating channel of the heat storage device is connected to the input end of the ammonia synthesis device in the first ammonia synthesis unit.

[0016] The output end of the ammonia synthesis compression device in the second ammonia synthesis unit is connected to the input end of the ammonia synthesis device in the second ammonia synthesis unit, and the output end of the ammonia synthesis device in the second ammonia synthesis unit is connected to the input end of the heat storage channel of the heat storage device, so as to store the excess heat generated by the ammonia synthesis device during the ammonia synthesis operation into the heat storage device.

[0017] Optionally, in the aforementioned ammonia synthesis system, the ammonia synthesis unit includes:

[0018] Ammonia synthesis compression equipment and ammonia synthesis equipment;

[0019] The input end of the ammonia synthesis compression device is connected to the output end of the hydrogen production device, and the output end of the ammonia synthesis compression device is connected to the input end of the heat supply channel of the heat storage device.

[0020] The output end of the heating channel of the heat storage device is connected to the input end of the ammonia synthesis device, and the output end of the ammonia synthesis device is connected to the input end of the heat storage channel of the heat storage device.

[0021] Optionally, the ammonia synthesis system described above may further include: a first heat exchange device;

[0022] The first heat exchange device is used to heat the gas output by the ammonia synthesis compression device using the excess heat generated by the ammonia synthesis unit during the ammonia synthesis operation.

[0023] Optionally, in the aforementioned ammonia synthesis system, the inlet of the cold fluid channel of the first heat exchange device is connected to the output end of the ammonia synthesis compression device; the outlet of the cold fluid channel of the first heat exchange device is connected to the input end of the ammonia synthesis device and / or the input end of the heat storage device; the inlet of the hot fluid channel of the first heat exchange device is connected to the output end of the ammonia synthesis device and / or the output end of the heat storage device; and the outlet of the hot fluid channel of the first heat exchange device is connected to the ammonia cooling and separation device.

[0024] Optionally, in the aforementioned ammonia synthesis system, the ammonia synthesis compression equipment includes:

[0025] A primary syngas compression unit and a secondary syngas compression unit are connected in sequence. The input end of the primary syngas compression unit is connected to the output end of the hydrogen production equipment, and the output end of the secondary syngas compression unit is connected to the first heat exchange device.

[0026] Optionally, in the aforementioned ammonia synthesis system, the ammonia cooling and separation equipment outputs circulating gas to the secondary compression unit of the synthesis gas.

[0027] Optionally, the ammonia synthesis system described above may further include: a second heat exchange device;

[0028] The second heat exchange device is used to use the excess heat generated by the ammonia synthesis unit during the ammonia synthesis operation to treat the demineralized water after the deoxygenation operation to obtain steam, and output the steam to the hydrogen production equipment and the ammonia synthesis compression equipment.

[0029] Optionally, in the aforementioned ammonia synthesis system, the inlet of the hot fluid channel of the second heat exchanger is connected to the ammonia synthesis equipment and / or the heat storage equipment, and the outlet of the hot fluid channel of the second heat exchanger is connected to the ammonia cooling and separation equipment; the inlet of the cold fluid channel of the second heat exchanger is connected to the demineralized water conveying pipeline; and the outlet of the cold fluid channel of the second heat exchanger is connected to the hydrogen production equipment and the ammonia synthesis compression equipment, respectively.

[0030] Optionally, in the aforementioned ammonia synthesis system, the hydrogen production equipment includes:

[0031] The unit includes a power generation unit and a hydrogen production unit, wherein the power generation unit is connected to the hydrogen production unit, and the output end of the hydrogen production unit is connected to the input end of the ammonia synthesis compression equipment.

[0032] Optionally, in the aforementioned ammonia synthesis system, the power generation unit includes:

[0033] Renewable energy power generation modules;

[0034] The renewable energy power generation module is connected to the hydrogen production unit.

[0035] An ammonia synthesis control method, applied to the aforementioned ammonia synthesis system, the ammonia synthesis control method comprising:

[0036] Obtain the current operating power of the ammonia synthesis system;

[0037] When the current operating power is greater than or equal to a preset first threshold, the heat storage device is controlled to store at least the excess heat generated by the ammonia synthesis unit during the ammonia synthesis operation;

[0038] When the current operating power is less than a preset first threshold, the heat stored in the heat storage device is used to heat the ammonia synthesis system.

[0039] Optionally, the above method can be applied when there are at least two ammonia synthesis units.

[0040] The control of the heat storage device to store at least the excess heat generated by the ammonia synthesis unit during the ammonia synthesis operation includes: determining the target ammonia synthesis unit based on the current operating power, controlling the valve of the branch where the target ammonia synthesis unit is located to open, so as to run the target ammonia synthesis unit; and controlling the second ammonia synthesis unit in the target ammonia synthesis unit to store the excess heat generated during the ammonia synthesis operation in the heat storage device.

[0041] The use of the heat stored in the heat storage device to heat the ammonia synthesis system includes: using the heat stored in the heat storage device to heat the first ammonia synthesis unit in the target ammonia synthesis unit, wherein the operating power of the first ammonia synthesis unit is less than a preset second threshold; and the operating power of the second ammonia synthesis unit is greater than or equal to the second threshold.

[0042] Optionally, in the above method, determining the target ammonia synthesis unit based on the current operating power includes:

[0043] Determine the target operating power range in which the current operating power falls;

[0044] Obtain the correspondence between the pre-configured operating power range and the ammonia synthesis unit;

[0045] The ammonia synthesis unit corresponding to the target operating power range can be obtained by querying the correspondence.

[0046] The ammonia synthesis unit corresponding to the target operating power range is taken as the target ammonia synthesis unit.

[0047] Compared with the prior art, the present invention has the following beneficial effects:

[0048] This invention provides an ammonia synthesis system and an ammonia synthesis control method. In the ammonia synthesis system, an ammonia synthesis unit performs ammonia synthesis operations. When the current operating power of the ammonia synthesis system is greater than or equal to a preset first threshold, a heat storage device in the ammonia synthesis system stores at least the excess heat generated by the ammonia synthesis unit during the ammonia synthesis operation. When the current operating power of the ammonia synthesis system is less than the first threshold, the stored heat is used to heat the ammonia synthesis system. Storing excess heat generated by the ammonia synthesis unit during ammonia synthesis operations through a heat storage device avoids heat waste. Using the stored heat to heat the ammonia synthesis system ensures thermal balance at low power, allowing the ammonia synthesis system to operate normally and improving its reliability. Attached Figure Description

[0049] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0050] Figure 1 This is a schematic diagram of an ammonia synthesis system provided in an embodiment of the present invention;

[0051] Figure 2 This is a schematic diagram of another ammonia synthesis system provided in an embodiment of the present invention;

[0052] Figure 3 This is a schematic diagram of another ammonia synthesis system provided in an embodiment of the present invention;

[0053] Figure 4 This is a schematic diagram of another ammonia synthesis system provided in an embodiment of the present invention;

[0054] Figure 5 This is a schematic diagram of the framework of an ammonia synthesis system provided in an embodiment of the present invention;

[0055] Figure 6 This is a flowchart of an ammonia synthesis control method provided in an embodiment of the present invention. Detailed Implementation

[0056] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0057] Green hydrogen produced from renewable energy sources faces challenges in storage and transportation.

[0058] Of all hydrogen-based energy sources, ammonia has the highest volumetric energy density, far exceeding that of pure hydrogen (at 700 bar, ammonia is 15.6 MJ / L, liquid hydrogen is 9.1 MJ / L, and compressed hydrogen is 5.6 MJ / L), and it is also easier to store and transport than liquid or compressed hydrogen. Therefore, ammonia is considered a better transportable fuel than hydrogen. However, the ammonia synthesis process requires a large amount of hydrogen. Currently, the hydrogen used in ammonia synthesis technologies is mostly derived from fossil fuels, leading to persistent environmental and energy consumption problems. Therefore, the synthesis of green ammonia from green hydrogen is of great significance for both environmental protection and energy utilization.

[0059] For environmentally friendly hydrogen production, renewable energy sources such as wind and solar power can be used. However, renewable energy is affected by weather, and hydrogen production fluctuates with changes in the input current of the hydrogen production equipment, resulting in unstable hydrogen output. When hydrogen production is low, the ammonia synthesis system operates at low power, and the heat generated cannot meet its own operational needs, leading to system malfunction and reduced reliability. Conversely, when hydrogen production is high, a significant amount of heat is generated that cannot be utilized promptly, resulting in heat waste. In short, when producing hydrogen using renewable energy, the fluctuating hydrogen output with changes in the input current of the equipment causes substantial fluctuations in the heat balance of the ammonia synthesis section.

[0060] To address this, the present invention employs a multi-system operating condition linkage approach involving high-power heat storage and low-power heat release to balance the problem of excess or insufficient heat caused by power changes. Simultaneously, it provides real-time hot start-up for the ammonia synthesis system with insulation, resulting in a rapid and more adaptable combined process.

[0061] Specifically, this invention provides an ammonia synthesis system and an ammonia synthesis control method. The ammonia synthesis system includes a heat storage device and at least one ammonia synthesis unit. The ammonia synthesis unit performs ammonia synthesis operations. The heat storage device stores excess heat generated by the ammonia synthesis unit during ammonia synthesis operations when the current operating power of the ammonia synthesis system is greater than or equal to a preset first threshold. When the current operating power of the ammonia synthesis system is less than the first threshold, the stored heat is used to heat the ammonia synthesis system, satisfying the thermal balance of the ammonia synthesis system at low power, ensuring normal operation of the ammonia synthesis system, and improving the reliability of the ammonia synthesis system. Furthermore, the heat storage device can also store excess heat from the ammonia synthesis system to provide heat when the ammonia synthesis system is insufficient, maintaining the thermal balance of the ammonia synthesis system.

[0062] Specifically, refer to Figure 1 The ammonia synthesis system provided in this embodiment of the invention may include:

[0063] Thermal storage device 101 and at least one ammonia synthesis unit 102;

[0064] The ammonia synthesis unit 102 is used to perform ammonia synthesis operations; in this embodiment, the ammonia synthesis unit performs ammonia synthesis operations to obtain ammonia-containing synthesis gas, and the number of ammonia synthesis units is one or more.

[0065] The heat storage device 101 is used to store at least the excess heat generated by the ammonia synthesis unit 102 when performing ammonia synthesis operation when the current operating power of the ammonia synthesis system is greater than or equal to a preset first threshold; and to use the stored heat to heat the ammonia synthesis system when the current operating power of the ammonia synthesis system is less than the first threshold.

[0066] In this embodiment, the heat source in the heat storage device 101 can be from the input of an external system or from the excess heat inside the ammonia synthesis system. When the current operating power of the ammonia synthesis system is greater than or equal to a preset first threshold, it is determined that the ammonia synthesis system is in a high-power condition, and the heat storage device can store the excess heat generated by the ammonia synthesis unit when performing the ammonia synthesis operation. When the current operating power of the ammonia synthesis system is less than the preset first threshold, it is determined that the ammonia synthesis system is in a low-power condition, and the heat storage device can use the stored heat to heat the ammonia synthesis system.

[0067] By applying the system provided in this embodiment of the invention, when the current operating power of the ammonia synthesis system is greater than or equal to a preset first threshold, excess heat generated by the ammonia synthesis unit during the ammonia synthesis operation can be stored in a heat storage device to avoid heat waste; when the current operating power of the ammonia synthesis system is less than the first threshold, the heat stored in the heat storage device can be used to heat the ammonia synthesis system, which can meet the thermal balance of the ammonia synthesis system at low power, so that the ammonia synthesis system can work normally and improve the reliability of the ammonia synthesis system.

[0068] In some embodiments, there are at least two ammonia synthesis units in the ammonia synthesis system; the heat storage device supplies heat to the first ammonia synthesis unit in each of the ammonia synthesis units; the heat storage device stores the excess heat generated by the second ammonia synthesis unit during the ammonia synthesis operation, and the second ammonia synthesis unit is the unit other than the first ammonia synthesis unit in each of the ammonia synthesis units.

[0069] In this embodiment, the first ammonia synthesis unit can be any ammonia synthesis unit, or it can be an ammonia synthesis unit with a lower operating power; optionally, the operating power of the first ammonia synthesis unit is less than the operating power of the second ammonia synthesis unit.

[0070] In some embodiments, the operating power ranges of the various ammonia synthesis units may be the same or different. For example, when there are two ammonia synthesis units, one operates in the low power range and the other operates in the high power range. If the number of ammonia synthesis units is greater than two, the different ammonia synthesis units can operate in the high, medium, and low power ranges, respectively.

[0071] In some embodiments, the operating power of the first ammonia synthesis unit is less than a preset second threshold; the operating power of the second ammonia synthesis unit is greater than or equal to the second threshold. In this embodiment, an ammonia synthesis unit with an operating power less than the second threshold can be designated as the first ammonia synthesis unit; and an ammonia synthesis unit with an operating power greater than or equal to the second threshold can be designated as the second ammonia synthesis unit.

[0072] See Figure 2 In the case where there are at least two ammonia synthesis units in the ammonia synthesis system, each ammonia synthesis unit includes: an ammonia synthesis compression device 1021 and an ammonia synthesis device 1022.

[0073] The output end of the ammonia synthesis compression device 1021 in the first ammonia synthesis unit of each ammonia synthesis unit is connected to the input end of the heating channel in the heat storage device 101, and the output end of the heating channel of the heat storage device 101 is connected to the input end of the ammonia synthesis device 1022 in the first ammonia synthesis unit.

[0074] The output end of the ammonia synthesis compression device 1021 in the second ammonia synthesis unit is connected to the input end of the ammonia synthesis device 1022 in the second ammonia synthesis unit. The output end of the ammonia synthesis device 1022 in the second ammonia synthesis unit is connected to the input end of the heat storage channel of the heat storage device 101, so as to store the excess heat generated by the ammonia synthesis device 1022 during the ammonia synthesis operation into the heat storage device 101.

[0075] Optionally, the heat storage device can obtain excess heat generated by the ammonia synthesis equipment in the second ammonia synthesis unit during ammonia synthesis operation through the heat storage channel; or it can supply heat to the ammonia synthesis equipment in the first ammonia synthesis unit through the heat supply channel.

[0076] In this embodiment, different ammonia synthesis units can be composed of different ammonia compression equipment and different ammonia synthesis equipment, or they can be composed of the same ammonia compression equipment and different ammonia synthesis equipment. That is, the ammonia compression equipment contained in different ammonia synthesis units can be the same or different.

[0077] Optionally, at least one ammonia synthesis unit is used to store the excess heat generated in a heat storage device, and at least one ammonia synthesis unit is used to consume the heat stored in the heat storage device.

[0078] Optionally, the excess heat generated by the ammonia synthesis equipment of the second ammonia synthesis unit during the ammonia synthesis operation can be input into the mixed gas of the ammonia synthesis equipment of the first ammonia synthesis unit through the heat storage device 101, so as to heat the mixed gas to a preset temperature, which is set according to the actual scenario.

[0079] In this embodiment, a heat storage device 101 is configured to provide the heat required by the ammonia synthesis system, satisfy the thermal balance of the ammonia synthesis system at low power, enable the ammonia synthesis system to work normally, and improve the reliability of the ammonia synthesis system.

[0080] Optionally, the ammonia synthesis compression equipment may include at least one synthesis gas compression unit, which can be used to compress hydrogen and nitrogen; the ammonia synthesis equipment may include an ammonia synthesis tower, which can be used for ammonia synthesis.

[0081] In some embodiments, when the number of ammonia synthesis units in the ammonia synthesis system is one, the connection method of the ammonia synthesis compression device 1021 and the ammonia synthesis device 1022 in the ammonia synthesis unit 102 can be referred to Figure 3 The input end of the ammonia synthesis compression device 1021 is connected to the output end of the hydrogen production device, and the output end of the ammonia synthesis compression device 1021 is connected to the input end of the heating channel of the heat storage device 101; the output end of the heating channel of the heat storage device 101 is connected to the input end of the ammonia synthesis device 1022, and the output end of the ammonia synthesis device 1022 is connected to the input end of the heat storage channel of the heat storage device 101.

[0082] In this embodiment, the ammonia compression device 1021 in the ammonia synthesis unit 102 can compress the received hydrogen, ammonia, and synthesis gas, and then transport the compressed gas to the heating channel of the heat storage device 101. The heat storage device 101 can use the stored heat to heat the gas output from the ammonia compression device 1021, and then output the heated gas to the ammonia synthesis device 1022, where the ammonia synthesis device 1022 performs ammonia synthesis to produce ammonia-containing synthesis gas. The ammonia synthesis device 1022 outputs the ammonia-containing synthesis gas to the heat storage channel of the heat storage device 101, so that the heat storage device 101 can store the heat carried in the ammonia-containing synthesis gas. That is, the heat storage device 101 can obtain the excess heat generated by the ammonia synthesis device in the ammonia synthesis unit during the ammonia synthesis operation through the heat storage channel; and use the stored heat to heat the gas output from the ammonia compression device 1021 in the ammonia synthesis unit 102.

[0083] In some embodiments, the ammonia synthesis system further includes a first heat exchange device 103; the first heat exchange device 103 can use the excess heat generated by the ammonia synthesis unit 102 during the ammonia synthesis operation to heat the gas output by the ammonia synthesis compression device.

[0084] In another embodiment, see Figure 4 The inlet of the cold fluid channel of the first heat exchange device 103 is connected to the output end of the ammonia synthesis compression device 1021; the outlet of the cold fluid channel of the first heat exchange device 103 is connected to the input end of the ammonia synthesis device 1022 and / or the input end of the heat storage device 101; the inlet of the hot fluid channel of the first heat exchange device is connected to the output end of the ammonia synthesis device 1022 and / or the output end of the heat storage device 101; and the outlet of the hot fluid channel of the first heat exchange device 103 is connected to the ammonia cooling separation device.

[0085] Optionally, the cold fluid channel outlet of the first heat exchange device can be connected to the input end of the heating channel of the heat storage device, and the hot fluid channel inlet of the first heat exchange device can be connected to the output end of the heat storage channel of the heat storage device.

[0086] It should be noted that, Figure 4 The ammonia synthesis compression equipment and ammonia synthesis equipment shown in the diagram may belong to the same ammonia synthesis unit or different ammonia synthesis units.

[0087] In some embodiments, the ammonia synthesis unit includes a primary synthesis gas compression unit and a secondary synthesis gas compression unit connected in sequence. The input end of the primary synthesis gas compression unit is connected to the output end of the hydrogen production unit, and the output end of the secondary synthesis gas compression unit is connected to the first heat exchange device.

[0088] In some embodiments, the ammonia cooling and separation equipment outputs circulating gas to the syngas secondary compression unit.

[0089] In some embodiments, the ammonia synthesis system further includes a second heat exchange device; the second heat exchange device can use the excess heat generated by the ammonia synthesis unit during the ammonia synthesis operation to treat the demineralized water after the deoxygenation operation to obtain steam, and output the steam to the hydrogen production equipment and the ammonia synthesis compression equipment.

[0090] In some embodiments, the inlet of the hot fluid channel of the second heat exchange device is connected to the ammonia synthesis device and / or the heat storage device, and the outlet of the hot fluid channel of the second heat exchange device is connected to the ammonia cooling and separation device; the inlet of the cold fluid channel of the second heat exchange device is connected to the demineralized water conveying pipeline; and the outlet of the cold fluid channel of the second heat exchange device is connected to the hydrogen production device and the ammonia synthesis compression device, respectively.

[0091] In some embodiments, the hydrogen production equipment includes a power generation unit and a hydrogen production unit, wherein the power generation unit is connected to the hydrogen production unit, and the output end of the hydrogen production unit is connected to the input end of the ammonia synthesis compression equipment.

[0092] In this embodiment, the power generation unit can provide electrical energy to the hydrogen production unit; the hydrogen production unit can be used to produce hydrogen and supply hydrogen to the ammonia synthesis compression equipment in the ammonia synthesis unit.

[0093] In some embodiments, the power generation unit includes: a renewable energy power generation module; the renewable energy power generation module is connected to the hydrogen production unit.

[0094] In this embodiment, the renewable energy power generation module may include at least one of the following: wind power generation module, photovoltaic power generation module, tidal power generation module, etc.; optionally, the power generation unit may also include an energy storage module, which can be used to store excess electrical energy generated by the renewable energy power generation module; in some embodiments, the power generation unit may also include a converter module, which may be a DC / DC converter module or an AC / DC converter module, depending on the type of renewable energy power generation module.

[0095] See Figure 5 The diagram below is a schematic diagram of an ammonia synthesis system provided in an embodiment of the present invention. The ammonia synthesis system includes a hydrogen production device, a heat storage device, a first heat exchange device, an ammonia cooling and separation device, a liquid ammonia storage device, a second heat exchange device, and at least one ammonia synthesis unit. An ammonia synthesis unit may consist of an ammonia synthesis compression device and an ammonia synthesis device.

[0096] The output end of the hydrogen production equipment is connected to the input end of the ammonia synthesis compression equipment. After passing through the cold fluid channel of the first heat exchange equipment, the output end of the ammonia synthesis compression equipment is connected to the input end of the heating channel of the heat storage equipment. The output end of the heating channel of the heat storage equipment is connected to the input end of at least one ammonia synthesis equipment so that when the ammonia synthesis system is in a low-power operation state, the heat in the heat storage equipment can be used to heat the ammonia synthesis system.

[0097] Optionally, different ammonia synthesis units can operate within different power ranges. For example, if there are two ammonia synthesis units, one can operate in the low power range and the other in the high power range.

[0098] In addition, the number of ammonia synthesis units can also be greater than two, such as three, operating in high, medium and low power ranges respectively.

[0099] See Figure 5 , Figure 5The system comprises two ammonia compression units: ammonia compression unit 1 and ammonia compression unit 2. There are also two ammonia synthesis units: ammonia synthesis unit 1 (e.g., ammonia synthesis tower 1) and ammonia synthesis unit 2 (e.g., ammonia synthesis tower 2). Ammonia compression unit 1 can form alternative ammonia synthesis unit 1 with ammonia synthesis unit 2; ammonia compression unit 1 can form alternative ammonia synthesis unit 2 with ammonia synthesis unit 1; and ammonia compression unit 2 can form alternative ammonia synthesis unit 3 with ammonia synthesis unit 1. During system operation, one or two ammonia synthesis units can be selected from these four alternative units for operation.

[0100] The output of the ammonia synthesis compression device of at least one ammonia synthesis unit is connected to the input of the heat storage device after passing through a first heat exchange device, and the output of the heat storage device is connected to the input of the corresponding ammonia synthesis device.

[0101] Optionally, the output end of the ammonia synthesis compression device 2 is connected to the input end of the heat storage device 13 via the first heat exchange device and valve F23. The output end of the heat storage device 13 is connected to the input end of the ammonia synthesis device 2 via valve F24. The output end of the ammonia synthesis device 2 is connected to the second heat exchange device.

[0102] The output end of the ammonia synthesis compression device 1 is connected to the input end of the ammonia synthesis device 1 via valve F13 after passing through the first heat exchange device. The output end of the ammonia synthesis device 1 is connected to the input end of the heat storage device 13 via valve F15. The output end of the heat storage device 13 is connected to the second heat exchange device via valve F16.

[0103] In addition, the output of ammonia synthesis equipment 1 can also be connected to the second heat exchange equipment via valve F14.

[0104] In this embodiment, the ammonia synthesis compression equipment includes a primary syngas compression unit and a secondary syngas compression unit connected in sequence. The input end of the primary syngas compression unit is connected to the output end of the hydrogen production equipment, and the output end of the secondary syngas compression unit is connected to the first heat exchange device. Taking the ammonia synthesis compression equipment 1 as an example, the hydrogen production equipment is connected to the primary syngas compression unit 1 in the ammonia synthesis compression equipment 1 through valve F11, the primary syngas compression unit 1 in the ammonia synthesis compression equipment 1 is connected to the secondary syngas compression unit 1 in the ammonia synthesis compression equipment 1, and the secondary syngas compression unit 1 is connected to the first heat exchange device through valve F12.

[0105] The connection relationship of the ammonia synthesis compression unit 2 is similar to that of the ammonia synthesis compression unit 1. The hydrogen production unit is connected to the primary syngas compression unit 2 in the ammonia synthesis compression unit 2 through valve F21. The primary syngas compression unit 2 in the ammonia synthesis compression unit 2 is connected to the secondary syngas compression unit 2 in the ammonia synthesis compression unit 2. The secondary syngas compression unit 2 is connected to the first heat exchange device through valve F22.

[0106] In this embodiment, the hydrogen production equipment includes a power generation unit, a hydrogen production unit, and a hydrogen buffer unit, which are connected sequentially. The power generation unit includes a renewable energy power generation module, an energy storage module, and a converter module; the renewable energy power generation module and the energy storage module are respectively connected to the hydrogen production unit through the converter module.

[0107] In off-grid or grid-connected scenarios, electricity is generated by wind power or photovoltaic power generation modules, and / or by using electrical energy storage modules. After rectification by the rectifier unit, the current is sent to the hydrogen production unit, where water is electrolyzed in the electrolyzer of the hydrogen production unit to produce hydrogen and oxygen.

[0108] Hydrogen gas is stored in a hydrogen buffer unit, such as a buffer tank, and then mixed with nitrogen gas in a certain proportion before entering the ammonia synthesis compression equipment. To accommodate variable power, this system is equipped with two ammonia synthesis compression equipment, ammonia synthesis compression equipment 1 and ammonia synthesis compression equipment 2, configured with an operating power ratio of 4:1. Ammonia synthesis compression equipment 1 is used in high operating power scenarios, and ammonia synthesis compression equipment 2 is used in low operating power scenarios.

[0109] Optionally, if the system contains multiple ammonia synthesis units composed of different ammonia compression devices, the operating power of each ammonia synthesis unit can be configured according to the operating power of the hydrogen production unit. For example, with three ammonia synthesis units, three operating power levels (high, medium, and low) can be allocated. With four ammonia synthesis units, four operating power levels (level 1, level 2, level 3, and level 4) can be allocated. In other words, in large-scale systems, operation can be segmented into multiple zones to accommodate different renewable energy output power ranges.

[0110] In this embodiment, the second heat exchange device, the first heat exchange device, the ammonia cooling and separation device, and the liquid ammonia storage device are connected in sequence. The second heat exchange device processes the demineralized water after deoxygenation to obtain steam, and outputs the steam to the hydrogen production device and the ammonia synthesis compression device. The ammonia cooling and separation device outputs recirculated gas to the secondary compression unit of the synthesis gas.

[0111] Specifically, when the current operating power of the ammonia synthesis system is greater than or equal to the first threshold, valves F11, F12, F13, F14, F15, and F16 are opened, and valves F21, F22, F23, F24, F25, and F26 are closed. This controls the hydrogen and ammonia mixture to enter the ammonia synthesis compression unit 1, where it merges with the circulating gas output from the ammonia cooling and separation unit, is pressurized, and then passes through the first heat exchange unit to increase its temperature before entering the ammonia synthesis tower 1 for the ammonia synthesis reaction. A bypass is added to the pipeline from the outlet of the ammonia synthesis tower 1 to the second heat exchange unit, and this bypass is connected to the heat storage unit 13. The flow rate of the circulating gas to the heat storage device 13 is adjusted by controlling the opening of valves F14 and / or F15 to store part of the heat. The remaining part is used to generate steam through the second heat exchange device at the outlet of the synthesis tower 1 to provide insulation for the hydrogen production equipment and to provide power for the compressor in the synthesis gas compression equipment. The circulating gas output from the ammonia synthesis tower 1 is cooled by the second heat exchange device and the first heat exchange device. The circulating gas is then separated into circulating gas and ammonia by the ammonia cooling and separation device. The ammonia is stored as a product in the liquid ammonia storage device. The circulating gas enters the secondary compression unit of the synthesis gas in the ammonia compression equipment as synthesis gas.

[0112] When the current operating power of the ammonia synthesis system is less than the first threshold, valves F21, F22, F23, F24, F25, and F26 are opened, and valves F11, F12, F13, F14, F15, and F16 are closed. The mixed gas of hydrogen and ammonia is controlled to enter the ammonia synthesis compression device 2, where it merges with the circulating gas and is pressurized. After passing through the first heat exchange device, it enters the heat storage device 13. The operating power of the heat storage device 13 is controlled by the controller to heat the mixed gas to the preset temperature, and then it enters the ammonia synthesis tower 2 to carry out the ammonia synthesis reaction.

[0113] In addition, the steam generation process is as follows: the deaerated water passes through a deaerator to remove oxygen from the deaerated water and protect the boiler equipment. Then, the deaerated water and the gas from the outlet of the ammonia synthesis tower pass through the second heat exchange equipment to generate steam to provide steam insulation for the hydrogen production equipment and power the compressor in the ammonia synthesis compression equipment.

[0114] In this embodiment, under high-power conditions, there is an abundance of heat. The heat generated by the ammonia synthesis gas is divided into two parts: one part generates steam to provide insulation for the hydrogen production section and power for the compressor, and the other part stores the heat through a heat storage device. This heat is used to heat the raw material gas after the synthesis gas compression device 2 when the heat of the synthesis tower 2 is insufficient. That is, this embodiment achieves the purpose of maintaining the thermal balance of the system, keeping the system warm and starting up, reducing start-ups and shutdowns to prevent equipment pressure fatigue, and enabling the system to start up quickly through heat storage technology.

[0115] In addition, setting up two or more ammonia synthesis units can make the whole system more stable, have a wider load range, and be able to operate at lower loads for longer periods of time. Smaller power ammonia synthesis units consume less thermal energy and have lower requirements for thermal storage equipment.

[0116] Based on the aforementioned ammonia synthesis system, another embodiment of the present invention provides an ammonia synthesis control method applied to the aforementioned ammonia synthesis system. The ammonia synthesis control method can be executed by a controller within the ammonia synthesis system. This controller can be integrated into any device within the ammonia synthesis system or can be separately configured from the various devices in the system. In some embodiments, the ammonia synthesis control method can also be executed by a control device connected to the ammonia synthesis system. The controller and control device can be used to control the opening and closing of the aforementioned valves, and can control the valve opening degree. A flowchart of the ammonia synthesis control method is shown below. Figure 6 As shown, it includes:

[0117] S601: Obtain the current operating power of the ammonia synthesis system.

[0118] In this embodiment, the operating status of the hydrogen production equipment can be obtained, thereby obtaining the real-time operating power of the hydrogen production equipment.

[0119] S602: When the current operating power is greater than or equal to a preset first threshold, control the heat storage device to store at least the excess heat generated by the ammonia synthesis unit during the ammonia synthesis operation.

[0120] S603: When the current operating power is less than a preset first threshold, the heat stored in the heat storage device is used to heat the ammonia synthesis system.

[0121] In one embodiment of the present invention, based on the above implementation process, optionally, when there are at least two ammonia synthesis units, the process in S602 of controlling the heat storage device to store at least the excess heat generated by the ammonia synthesis unit during the ammonia synthesis operation includes: determining a target ammonia synthesis unit based on the current operating power; controlling the valve of the branch where the target ammonia synthesis unit is located to open to operate the target ammonia synthesis unit; and controlling the second ammonia synthesis unit in the target ammonia synthesis unit to store the excess heat generated during the ammonia synthesis operation in the heat storage device. The process in S603 of using the heat stored in the heat storage device to heat the ammonia synthesis system includes: using the heat stored in the heat storage device to heat the first ammonia synthesis unit in the target ammonia synthesis unit. In this embodiment, the operating power of the first ammonia synthesis unit is less than a preset second threshold; the operating power of the second ammonia synthesis unit is greater than or equal to the second threshold.

[0122] In one embodiment of the present invention, based on the above implementation process, optionally, determining the target ammonia synthesis unit according to the current operating power includes:

[0123] Determine the target operating power range in which the current operating power falls;

[0124] Obtain the correspondence between the pre-configured operating power range and the ammonia synthesis unit;

[0125] The ammonia synthesis unit corresponding to the target operating power range can be obtained by querying the correspondence.

[0126] The ammonia synthesis unit corresponding to the target operating power range is taken as the target ammonia synthesis unit.

[0127] In this embodiment, when there are multiple ammonia synthesis units, the operating power range can be divided into a high-power / low-power range and a low-power / low-power range. Each range has a defined operating power range, allowing the range to be determined based on the current operating power value.

[0128] Optionally, in the high power / high power range, an ammonia synthesis unit consisting of ammonia compression device 1 and ammonia synthesis device 1 can be operated; in the low power / low power range, an ammonia synthesis unit consisting of ammonia compression device 2 and ammonia synthesis device 2 can be operated.

[0129] In this embodiment, to clearly describe the process of opening the valves in the branch where the target ammonia synthesis unit is located to operate the target ammonia synthesis compression equipment and the target ammonia synthesis equipment, the following is combined with... Figure 5 Explanation:

[0130] If the ammonia synthesis unit consisting of the ammonia compression device 1 and the ammonia synthesis device 1 is in operation, then control valves F11, F12, F13, F14, F15, and F16 are opened, and F21, F22, F23, F24, F25, and F26 are closed, so that the ammonia compression device 1 and the branch where the ammonia synthesis device 1 is located are connected, and the ammonia compression device 1 and the ammonia synthesis device 1 operate normally.

[0131] If the ammonia synthesis unit consisting of the ammonia compression device 2 and the ammonia synthesis device 2 is in operation, then control valves F21, F22, F23, F24, F25, and F26 are opened, and F11, F12, F13, F14, F15, and F16 are closed, so that the ammonia compression device 2 and the branch where the ammonia synthesis device 2 is located are connected, and the ammonia compression device 2 and the ammonia synthesis device 2 operate normally.

[0132] In addition to controlling the opening and closing of valves F21, F22, F23, F24, F25, F26, F11, F12, F13, F14, F15, and F16, the controller can also control the valve opening degree. For example, under high-power conditions, part of the steam generated provides insulation for the hydrogen production section and power for the compressor, while the other part stores heat through a heat storage device. The specific amount of heat to be stored in the heat storage device can be adjusted by controlling the opening degree of F14, so as to ensure both the thermal balance of the ammonia synthesis system and the storage of a larger amount of heat, avoiding heat waste.

[0133] This embodiment uses two ammonia synthesis units as an example for illustration. When there are three, four or more ammonia synthesis units in operation, the control method is similar. At this time, the corresponding relationship between the operating power range, the ammonia synthesis unit, and the ammonia synthesis unit is also pre-configured, so that the corresponding ammonia synthesis unit and the ammonia synthesis unit are selected to work based on the corresponding relationship.

[0134] When there are three, four or more ammonia synthesis units, at least one ammonia synthesis unit can be selected to store heat, similar to the ammonia synthesis compression device 1 and ammonia synthesis device 1 mentioned above. Alternatively, at least one ammonia synthesis unit can be selected to consume heat, as in the ammonia synthesis compression device 2 and ammonia synthesis device 2 mentioned above.

[0135] For example, when there are three ammonia synthesis units (compression and synthesis), one set of ammonia synthesis units stores heat, while two sets consume heat. The specific configuration can be determined by technicians based on the actual scenario.

[0136] In this embodiment, by controlling the opening and closing of the corresponding valves, the energy is rationally utilized under high-power conditions. The heat generated by the ammonia synthesis gas is divided into two parts: one part generates steam to provide insulation for the hydrogen production section and power for the compressor, and the other part stores the heat through a heat storage device. This heat is used to heat the raw material gas after the synthesis gas compression device 2 when the heat of the synthesis tower 2 is insufficient. That is, this embodiment achieves the purpose of maintaining the thermal balance of the system, keeping the system warm and starting up, reducing start-up and shutdown to prevent equipment pressure fatigue, and enabling the system to start up quickly through heat storage technology.

[0137] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, produce implementations for the methods, apparatus, and computer program products according to embodiments of this application. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0138] In a typical configuration, the device includes one or more processors (CPUs), memory, and a bus. The device may also include input / output interfaces, network interfaces, etc.

[0139] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, like read-only memory (ROM) or flash RAM, and memory includes at least one memory chip. Memory is an example of computer-readable media.

[0140] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0141] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0142] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0143] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. An ammonia synthesis system, characterized in that, include: A heat storage device and at least two ammonia synthesis units for performing ammonia synthesis operations; each of the ammonia synthesis units includes an ammonia synthesis compression device and an ammonia synthesis device; The output end of the ammonia synthesis compression device in the first ammonia synthesis unit of each of the ammonia synthesis units is connected to the input end of the heating channel in the heat storage device; the output end of the heating channel of the heat storage device is connected to the input end of the ammonia synthesis device in the first ammonia synthesis unit. The heat storage device is used to store at least the excess heat generated by the second ammonia synthesis unit during the ammonia synthesis operation when the current operating power of the ammonia synthesis system is greater than or equal to a preset first threshold; and to use the stored heat to heat the first ammonia synthesis unit among the ammonia synthesis units when the current operating power of the ammonia synthesis system is less than the first threshold. The second ammonia synthesis unit is any unit other than the first ammonia synthesis unit among the ammonia synthesis units. The output end of the ammonia synthesis compression device in the second ammonia synthesis unit is connected to the input end of the ammonia synthesis device in the second ammonia synthesis unit. The output end of the ammonia synthesis device in the second ammonia synthesis unit is connected to the input end of the heat storage channel of the heat storage device, so as to store the excess heat generated by the ammonia synthesis device during the ammonia synthesis operation into the heat storage device.

2. The ammonia synthesis system according to claim 1, characterized in that, The operating power of the first ammonia synthesis unit is less than a preset second threshold; the operating power of the second ammonia synthesis unit is greater than or equal to the second threshold.

3. The ammonia synthesis system according to claim 1, characterized in that, The ammonia synthesis unit includes: Ammonia synthesis compression equipment and ammonia synthesis equipment; The input end of the ammonia synthesis compression device is connected to the output end of the hydrogen production device, and the output end of the ammonia synthesis compression device is connected to the input end of the heat supply channel of the heat storage device. The output end of the heating channel of the heat storage device is connected to the input end of the ammonia synthesis device, and the output end of the ammonia synthesis device is connected to the input end of the heat storage channel of the heat storage device.

4. The ammonia synthesis system according to claim 3, characterized in that, The ammonia synthesis system further includes: a first heat exchange device; The first heat exchange device is used to heat the gas output by the ammonia synthesis compression device using the excess heat generated by the ammonia synthesis unit during the ammonia synthesis operation.

5. The ammonia synthesis system according to claim 4, characterized in that, The inlet of the cold fluid channel of the first heat exchange device is connected to the output end of the ammonia synthesis compression device; the outlet of the cold fluid channel of the first heat exchange device is connected to the input end of the ammonia synthesis device and / or the input end of the heat storage device; the inlet of the hot fluid channel of the first heat exchange device is connected to the output end of the ammonia synthesis device and / or the output end of the heat storage device; and the outlet of the hot fluid channel of the first heat exchange device is connected to the ammonia cooling separation device.

6. The ammonia synthesis system according to claim 5, characterized in that, The ammonia synthesis compression equipment includes: A primary syngas compression unit and a secondary syngas compression unit are connected in sequence. The input end of the primary syngas compression unit is connected to the output end of the hydrogen production equipment, and the output end of the secondary syngas compression unit is connected to the first heat exchange device.

7. The ammonia synthesis system according to claim 6, characterized in that, The ammonia cooling and separation equipment outputs circulating gas to the secondary compression unit of the syngas.

8. The ammonia synthesis system according to claim 3, characterized in that, The ammonia synthesis system also includes: a second heat exchange device; The second heat exchange device is used to use the excess heat generated by the ammonia synthesis unit during the ammonia synthesis operation to treat the demineralized water after the deoxygenation operation to obtain steam, and output the steam to the hydrogen production equipment and the ammonia synthesis compression equipment.

9. The ammonia synthesis system according to claim 8, characterized in that, The inlet of the hot fluid channel of the second heat exchanger is connected to the ammonia synthesis equipment and / or the heat storage equipment, and the outlet of the hot fluid channel of the second heat exchanger is connected to the ammonia cooling and separation equipment; the inlet of the cold fluid channel of the second heat exchanger is connected to the demineralized water conveying pipeline; and the outlet of the cold fluid channel of the second heat exchanger is connected to the hydrogen production equipment and the ammonia synthesis compression equipment, respectively.

10. The ammonia synthesis system according to claim 3, characterized in that, The hydrogen production equipment includes: The unit includes a power generation unit and a hydrogen production unit, wherein the power generation unit is connected to the hydrogen production unit, and the output end of the hydrogen production unit is connected to the input end of the ammonia synthesis compression equipment.

11. The ammonia synthesis system according to claim 10, characterized in that, The power generation unit includes: Renewable energy power generation modules; The renewable energy power generation module is connected to the hydrogen production unit.

12. A method for controlling ammonia synthesis, characterized in that, The ammonia synthesis control method, applied to the ammonia synthesis system according to any one of claims 1-11, comprises: Obtain the current operating power of the ammonia synthesis system; When the current operating power is greater than or equal to a preset first threshold, the heat storage device is controlled to store at least the excess heat generated by the ammonia synthesis unit during the ammonia synthesis operation; When the current operating power is less than a preset first threshold, the heat stored in the heat storage device is used to heat the ammonia synthesis system.

13. The ammonia synthesis control method according to claim 12, characterized in that, When there are at least two ammonia synthesis units The control of the heat storage device to store at least the excess heat generated by the ammonia synthesis unit during the ammonia synthesis operation includes: determining the target ammonia synthesis unit based on the current operating power, controlling the valve of the branch where the target ammonia synthesis unit is located to open, so as to run the target ammonia synthesis unit; and controlling the second ammonia synthesis unit in the target ammonia synthesis unit to store the excess heat generated during the ammonia synthesis operation in the heat storage device. The use of the heat stored in the heat storage device to heat the ammonia synthesis system includes: using the heat stored in the heat storage device to heat the first ammonia synthesis unit in the target ammonia synthesis unit, wherein the operating power of the first ammonia synthesis unit is less than a preset second threshold; and the operating power of the second ammonia synthesis unit is greater than or equal to the second threshold.

14. The ammonia synthesis control method according to claim 13, characterized in that, The step of determining the target ammonia synthesis unit based on the current operating power includes: Determine the target operating power range in which the current operating power falls; Obtain the correspondence between the pre-configured operating power range and the ammonia synthesis unit; The ammonia synthesis unit corresponding to the target operating power range can be obtained by querying the correspondence. The ammonia synthesis unit corresponding to the target operating power range is taken as the target ammonia synthesis unit.

Images