A constant pressure ammonia supply control system and its control method

Abstract

This invention discloses an ammonia constant-pressure supply control system and its control method, relating to the field of semiconductor specialty gas supply. The system includes a weighing unit, a liquid storage unit, a heating unit, a pressure regulating unit, a distribution unit, a buffer unit, an analysis unit, a purging unit, and a control unit. Its advantages lie in the inclusion of a spare liquid storage element. The weighing unit performs weighing detection on the liquid storage unit, and the heating unit heats the liquid storage unit to different degrees to ensure that when the currently used liquid storage unit is exhausted, switching and bottle replacement are performed, thus ensuring the continuity of ammonia supply. The heating unit heats the liquid storage unit, buffer unit, and pipelines to ensure sufficient ammonia evaporation and prevent ammonia liquefaction. A buffer unit is also included to maintain a constant ammonia supply pressure in the face of sudden large flow demands, ensuring a stable supply. Finally, the analysis unit monitors ammonia leakage in real time to ensure the safe and stable operation of the system.

Description

Technical Field

[0001] This invention relates to the field of high-purity ammonia supply for semiconductors, and more particularly to a high-purity ammonia constant-pressure supply control system and its control method. Background Technology

[0002] Ammonia, an inorganic compound with the chemical formula NH3, is colorless and has a strong, pungent odor. It is easily liquefied into a colorless liquid by applying pressure at room temperature. It is soluble in water, ethanol, and ether. At high temperatures, it decomposes into nitrogen and hydrogen. It has a reducing effect and can be oxidized to nitric oxide in the presence of a catalyst. It is used to produce liquid nitrogen, ammonia water, nitric acid, ammonium salts, and amines. It can be synthesized directly from nitrogen and hydrogen. It can burn the skin, eyes, and mucous membranes of the respiratory organs. Inhaling too much can cause lung swelling and even death, making it extremely dangerous.

[0003] Currently, ammonia supply systems are primarily used in flue gas treatment systems that use ammonia as a reactant, such as ammonia-based flue gas desulfurization and denitrification systems. A typical ammonia process system using liquid ammonia as feedstock follows: liquid ammonia is stored in a storage tank, flows into an evaporator to absorb heat and be forcibly evaporated into ammonia gas, and the ammonia gas exiting the evaporator flows into an ammonia buffer tank to provide the necessary ammonia gas for subsequent systems.

[0004] In the prior art, Chinese invention patent CN117231912A discloses a liquid ammonia filling device, method, and semiconductor process system. The device includes a liquid supply unit, a liquid storage unit, an analysis unit, a filling unit, a reflux unit, a pressure relief unit, and a purging unit. By setting up an analysis unit and communicating with the liquid storage unit, the analysis unit can analyze the ammonia gas in the liquid storage unit and obtain the analysis results. The device then transports the ammonia gas and liquid ammonia in the liquid storage unit to the filling unit and the reflux unit according to the analysis results. Furthermore, by setting up pressure relief units that are respectively communicated with the liquid storage unit and the filling unit, the device can relieve pressure in the liquid storage unit and the filling unit to ensure the operational safety of the device.

[0005] However, the system's liquid storage unit has no backup components, nor any related monitoring components to monitor the use of liquid ammonia in the liquid storage unit in real time, making it impossible to guarantee an uninterrupted supply of ammonia; it also lacks a buffer unit with heating elements, which cannot guarantee the constant pressure of the main pipeline when dealing with sudden large flow demands, thus failing to guarantee a constant and stable supply of ammonia; furthermore, there are no leakage monitoring components to detect whether there is ammonia leakage, which cannot guarantee the personal safety of system personnel.

[0006] Ammonia is also used as a raw material gas in semiconductor manufacturing. Existing ammonia-requiring equipment has very strict requirements for the stability and purity of ammonia, but the ammonia input to the existing supply system has poor stability and unstable pressure, which affects the production efficiency of the equipment. Furthermore, there are no relevant safety measures. Therefore, a constant pressure ammonia supply device is proposed to solve the above problems. Summary of the Invention

[0007] To address the shortcomings of existing technologies and achieve the above objectives, the present invention adopts the following technical solution: A liquid storage unit is used to store liquid ammonia to obtain ammonia gas. A weighing unit is placed below the liquid storage unit and is used to detect the weight of the ammonia cylinder and the liquid ammonia stored inside it. A heating unit is attached externally to the liquid storage unit and its pipelines to obtain sufficient ammonia evaporation and prevent ammonia from liquefying in the pipelines; A pressure regulating unit is connected to the liquid storage unit via a pipeline to regulate the pressure of ammonia gas inside the pipeline. A distribution unit, which is connected to the pressure regulating unit via a pipeline to form a main pipeline, is used to distribute ammonia to different gas-using equipment and systems. A buffer unit, which is connected to the pressure regulating unit and the distribution unit via a pipeline, is used to stabilize the pressure of the main pipeline between the pressure regulating unit and the distribution unit; An analysis unit, located within the pressure regulating unit and the distribution unit, is used to monitor ammonia leakage. A purging unit, which is connected to the liquid storage unit and the pressure regulating unit through a pipeline, is used to purge impurities in the pressure regulating unit and the pipeline. The control unit is connected to the weighing unit, the liquid storage unit, the heating unit, the purging unit, the pressure regulating unit, the buffer unit, and the distribution unit, respectively, and is used to control the stable operation of the entire system.

[0008] In some embodiments, the liquid storage unit includes: At least one liquid storage element is connected to the pressure regulating unit and the purging unit respectively, for obtaining ammonia gas; At least one backup liquid storage element is provided. The backup liquid storage element is connected to the pressure regulating unit and the purging unit respectively. It is used to switch to the backup liquid storage element for ammonia supply when the liquid ammonia in the original liquid storage element is used up, and then switch to the original liquid storage element. After the original liquid storage element is used up, it will be replaced with the backup liquid storage element filled with liquid ammonia, i.e., bottle changing operation.

[0009] In some embodiments, the weighing unit includes: A weighing element is placed below the liquid storage element and the backup liquid storage element. The weighing element weighs the liquid storage element and the backup liquid storage element to monitor the remaining amount of liquid ammonia.

[0010] In some embodiments, the heating unit includes: A heating element is externally attached to the liquid storage element, the backup liquid storage element, and the buffer unit; the heating element heats the liquid storage element and the backup liquid storage element to obtain sufficient ammonia evaporation; the heating element heats the buffer unit to prevent ammonia liquefaction within the buffer unit; A heat tracing element is attached to the outside of the pipeline between the liquid storage unit, the pressure regulating unit, the distribution unit, and the buffer unit. The pipeline between the liquid storage unit, the pressure regulating unit, the distribution unit, and the buffer unit is heated to prevent the ammonia gas inside the pipeline from liquefying.

[0011] In some embodiments, the voltage regulating unit includes: At least one pressure regulating element is connected to the liquid storage unit, the purging unit, the distribution unit and the buffer unit through pipelines, and is used to regulate the high-pressure ammonia gas from the liquid storage unit to a relatively low-pressure ammonia gas and deliver it to the distribution unit and the buffer unit.

[0012] In some embodiments, the allocation unit includes: A distribution element, which is connected to the pressure regulating unit and the buffer unit, is used to distribute ammonia gas from the pressure regulating unit and the buffer unit to the equipment that needs to use the gas.

[0013] In some embodiments, the buffer unit includes: A buffer element is provided, which is connected to the pressure regulating unit and the distribution unit. The buffer element contains a certain amount of gaseous ammonia gas to stabilize the pressure of the main pipeline between the pressure regulating unit and the distribution unit.

[0014] In some embodiments, the analysis unit includes: The first analytical element is used to monitor ammonia leakage in the pressure regulating unit; The second analytical element is used to monitor ammonia leakage in the distribution unit.

[0015] In some embodiments, the purging unit includes: A purging element, which is connected to the pressure regulating unit, is used to purge the pressure regulating unit and pipelines.

[0016] In some embodiments, the control unit includes: The first controller element controls the heating start-up, heating stop-up, and heating temperature of the heating element and the heating tape element to ensure sufficient ammonia evaporation and prevent ammonia liquefaction in the buffer element and pipeline. The second controller element controls the liquid storage element, the backup liquid storage element, the pressure regulating element, and the purging unit to provide ammonia gas at a constant pressure and to automate the switching of the liquid storage element to the backup liquid storage element and the replacement of the original liquid storage element. The third controller element receives signals from the first and second analysis elements and is used to handle the ammonia leak emergency. The third controller element is connected to the first and second controller elements and receives and processes data from the entire system.

[0017] In some embodiments, the liquid storage unit further includes: Furthermore, when the liquid storage unit contains multiple liquid storage elements, the heating unit will heat the multiple liquid storage elements to different degrees under the control of the first controller element, so that the multiple liquid storage elements can be used up at the same time, thereby switching and changing bottles simultaneously.

[0018] Furthermore, when the liquid storage unit has multiple liquid storage elements, there will be the same number of spare liquid storage elements.

[0019] In some embodiments, the heating unit further includes: At least one temperature monitoring element is placed inside the heating element and the heat tracing element to monitor the temperature of the heating element and the heat tracing element.

[0020] In some embodiments, the voltage regulating unit further includes: A first pressure monitoring element is disposed in the pipeline between the pressure regulating unit and the liquid storage unit, and is used to monitor the pressure of ammonia gas before pressure regulation. The second pressure monitoring element is disposed in the pipeline between the pressure regulating unit, the buffer unit, and the distribution unit, and is used to monitor the pressure of ammonia gas after pressure regulation.

[0021] Furthermore, the pressure regulating element and pipeline are placed in a professional explosion-proof special gas cabinet to prevent accidents caused by ammonia leakage.

[0022] Furthermore, the first analytical element is placed around the special gas cabinet containing the pressure regulating element to monitor ammonia leakage.

[0023] In some embodiments, the buffer unit further includes: The third pressure monitoring element is located downstream of the pipeline between the buffer element and the pressure regulating unit, and is used to monitor the pressure of ammonia gas stored in the buffer element.

[0024] This invention provides a control method for an ammonia constant pressure supply control system, which is applied to the aforementioned ammonia constant pressure supply control system.

[0025] The control method of the ammonia constant pressure supply control system is characterized in that: the heating element heats the liquid storage element under the control of the first controller element, so that the liquid ammonia stored in the liquid storage element is vaporized into high-pressure ammonia gas and flows to the pressure regulating element. Under the control of the second controller element, the pressure regulating element reduces the pressure of the high-pressure ammonia gas into low-pressure ammonia gas. The low-pressure ammonia gas flows to the distribution element and the buffer element. After being distributed by the distribution element, the low-pressure ammonia gas flows to the equipment in use. The heating element heats the system pipeline throughout the entire process.

[0026] Furthermore, when multiple ammonia-using devices simultaneously consume large amounts of ammonia, the pressure in the main pipeline between the pressure regulating element and the distribution element will drop rapidly, causing supply difficulties. At this time, the first controller element detects the rapid pressure drop and will use the backup liquid storage element for supply. If the pressure still cannot be stabilized at the normal level, the low-pressure ammonia stored in the buffer element will be used for auxiliary supply, thereby ensuring the pressure in the main pipeline remains stable.

[0027] Furthermore, when there is sufficient low-pressure ammonia in the main pipeline, the pressure in the main pipeline returns to the normal level. At this time, the buffer element stops providing auxiliary supply, and sufficient low-pressure ammonia is added to the buffer element until its internal pressure is equal to the ammonia pressure in the main pipeline. Under the control of the first controller element, the heating element is controlled to heat the buffer element to prevent the ammonia stored in the buffer unit from liquefying.

[0028] Furthermore, when there are several liquid storage elements, the first controller element will determine the remaining amount of liquid ammonia in the several liquid storage elements based on the weight signals transmitted by the several weighing elements, and set different heating temperatures for the several liquid storage elements based on the remaining amount of liquid ammonia in the several liquid storage elements, so as to ensure that the liquid ammonia in the several liquid storage elements can be used up at the same time for convenient switching and bottle changing.

[0029] Furthermore, when the amount of liquid ammonia in the liquid storage element is insufficient, the second controller source element will control the ammonia source to switch to the backup liquid storage element, which will then become the liquid storage unit. The original liquid storage unit will become the backup liquid storage unit after the bottle is changed.

[0030] The present invention adopts the above technical solution and has the following technical effects compared with the prior art: The system is equipped with a backup liquid storage element. A weighing unit monitors the weight of the storage element, and a heating unit heats the element to varying degrees to ensure a continuous ammonia supply. This allows for switching and bottle replacement when the currently used storage element is depleted. The heating unit also heats the pipelines between the storage and buffer units, as well as between the storage, pressure regulating, and distribution units, ensuring sufficient ammonia evaporation and preventing liquefaction of ammonia in the pipelines and buffer units. A buffer unit located beside the main pipeline maintains constant pressure in the main pipeline during sudden surges in flow demand, ensuring a stable ammonia supply. An analysis unit monitors ammonia leakage in real time to ensure stable system operation and the safety of personnel. This invention features a scientifically sound and rationally designed structure, resulting in a stable ammonia supply. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of an ammonia constant pressure supply control system.

[0033] Figure 2 This is a schematic diagram of the liquid storage unit.

[0034] Figure 3 This is a schematic diagram of the voltage regulating unit.

[0035] Figure 4 This is a schematic diagram of a buffer unit.

[0036] Figure 5This is a schematic diagram of the heating unit.

[0037] Figure 6 This is a schematic diagram of the analysis unit.

[0038] In the diagram: 100, Weighing unit; 200, Liquid storage unit; 300, Heating unit; 400, Pressure regulating unit; 500, Distribution unit; 600, Buffer unit; 700, Analysis unit; 800, Purge unit; 900, Control unit; 110, First weighing element; 120, Second weighing element; 210, Liquid storage element; 220, Backup liquid storage element; 230, Liquid storage valve element; 240, Backup liquid storage valve element; 310, First heating element; 320. Second heating element; 330, third heating element; 340, heating tape element; 350, first temperature monitoring element; 360, second temperature monitoring element; 370, third temperature monitoring element; 380, fourth temperature monitoring element; 410, pressure regulating element; 420, first pressure monitoring element; 430, second pressure monitoring element; 440, first valve element; 450, second valve element; 460, third valve element; distribution element 510; 610, buffer element; 620, third pressure monitoring element; 710, first analysis element; 720, second analysis element; 910, first controller element; 920, second controller element; 930, third controller element. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0040] The embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0041] like Figure 1As shown, an ammonia constant pressure supply control system includes a weighing unit 100, a liquid storage unit 200, a heating unit 300, a pressure regulating unit 400, a distribution unit 500, a buffer unit 600, an analysis unit 700, a purging unit 800, and a control unit 900. The liquid storage unit 200 stores liquid ammonia to obtain ammonia gas. The weighing unit 100 is located below the liquid storage unit 200 and is used to detect the remaining amount of liquid ammonia. The heating unit 300 is attached externally to the pipes between the liquid storage unit 200, the buffer unit 600, and the pipes between the liquid storage unit 200, the pressure regulating unit 400, the distribution unit 500, and the buffer unit 600, to obtain sufficient ammonia evaporation and prevent ammonia liquefaction within the buffer unit 600 and the pipes. The liquid storage unit 200 generates high-pressure ammonia gas. The ammonia gas flows to the pressure regulating unit 400; the pressure regulating unit 400 is connected to the liquid storage unit 200, the distribution unit 500, the buffer unit 600, and the purging unit 700 via pipelines, and is used to regulate the pressure of the high-pressure ammonia gas from the liquid storage unit 100; the pressure regulating unit 400 directs the regulated ammonia gas to the distribution unit 500 and the buffer unit 600; the distribution unit 500 is connected to the pressure regulating unit 400 and the buffer unit 600 via pipelines, and is used to distribute the ammonia gas to different gas-using equipment and systems; the buffer unit 600... The system is connected to the pressure regulating unit 400 and the distribution unit 500 via pipelines to stabilize the pressure in the main pipeline between the pressure regulating unit and the distribution unit. When the ammonia pressure in the buffer unit 600 is higher than the ammonia pressure in the main pipeline, the ammonia in the buffer unit 600 flows to the distribution unit 500. When the ammonia pressure in the buffer unit 600 is lower than the ammonia pressure in the main pipeline, the ammonia regulated by the pressure regulating unit 400 flows to the buffer unit 600. The analysis unit 700 is located in the pressure regulating unit 400 and the distribution unit 500 to monitor ammonia leakage. The purging unit 800 is connected to the liquid storage unit 200 and the pressure regulating unit 400 via pipelines to purge impurities in the pressure regulating unit 400 and the pipeline. The control unit 900 is connected to the weighing unit 100, the liquid storage unit 200, the heating unit 300, the pressure regulating unit 400, the distribution unit 500, the buffer unit 600, the analysis unit 700, and the purging unit 800 to control the stable operation of the entire system.

[0042] like Figure 2 As shown, the weighing unit 100 includes a first weighing element 110 and a second weighing element 120, used to monitor the remaining amount of liquid ammonia.

[0043] The liquid storage unit 200 includes a liquid storage element 210, a standby liquid storage element 220, a liquid storage valve element 230, and a standby liquid storage valve element 240; wherein, the liquid storage element 210 and the standby liquid storage element 230 are connected to the pressure regulating unit 400 and the purging unit 800 through pipelines, and are connected to the first controller element 910 of the heating unit 300 and the control unit 900; the liquid storage valve element 230 and the standby liquid storage valve element 240 control whether the high-pressure ammonia gas in the liquid storage element 210 and the standby liquid storage element 230 flows to the pressure regulating unit 400.

[0044] In some specific embodiments, the liquid storage element 210 and the standby liquid storage element 220 are liquid ammonia storage tanks.

[0045] Specifically, the liquid storage element 210 and the standby liquid storage element 220 include a liquid supply source and an air outlet. The air outlet is connected to the liquid storage valve element 230 and the standby liquid storage valve element 240 and is connected to the pressure regulating unit 400 through a pipeline.

[0046] Furthermore, the first weighing element 110 is placed below the liquid storage element 210 for weighing and monitoring, and the second weighing element 120 is placed below the spare liquid storage element 220 for weighing and monitoring. The weighing and monitoring is used to monitor the remaining amount of liquid ammonia used.

[0047] Preferably, after the liquid ammonia in the liquid storage element 210 is used up, the gas supply source will be switched to the backup liquid storage unit 220 under the control of the first controller element 910 of the control unit 900 and a bottle replacement operation will be performed, and the original backup liquid storage element 220 will become the liquid storage element 210; after the bottle replacement operation is completed, the original liquid storage element 210 will become the backup liquid storage element 220.

[0048] When there are multiple liquid storage elements 210, the multiple liquid storage elements 210 are arranged in parallel; the number of spare liquid storage elements 220 is the same as the number of liquid storage elements 210, and the number of the first weighing element 110 and the second weighing element 220 are also the same as the number of liquid storage elements 210.

[0049] like Figure 3 As shown, the pressure regulating unit 400 includes a pressure regulating element 410, a first pressure monitoring element 420, a second pressure monitoring element 430, a first valve element 440, a second valve element 450, and a third valve element 460; wherein the pressure regulating element 410 is connected to the liquid storage unit 200 through a pipeline, the first valve element is connected to the distribution unit 500 through a pipeline, the second valve element 450 is connected to the buffer unit 600 through a pipeline, and the third valve element 460 is connected to the purging unit 800 through a pipeline; the first pressure monitoring element 420, the second pressure monitoring element 430, the first valve element 440, the second valve element 450, and the third valve element 460 are connected to the second controller element 920 of the control unit 900.

[0050] The pressure regulating element 410, the first pressure monitoring element 420, the second pressure monitoring element 430, the first valve element 440, the second valve element 450 and the third valve element 460 are all placed in a special gas cabinet with explosion-proof function.

[0051] The pipeline connecting the liquid storage unit 200 and the pressure regulating element 410 is the first pipeline, and there are several first pipelines arranged in parallel.

[0052] Preferably, the first pressure monitoring element 420 is located downstream of the first pipeline, that is, close to the pressure regulating element 410, and is used to monitor the pressure of the high-pressure ammonia gas in the liquid storage unit 200 before it enters the pressure regulating element 410.

[0053] In some specific embodiments, the first conduit includes, but is not limited to, heating using a heating cable.

[0054] Furthermore, when there are multiple first valve elements 440, the multiple first valve elements 440 are arranged in parallel.

[0055] Specifically, the first valve element 440 includes, but is not limited to, ball valves and butterfly valves.

[0056] Preferably, the pipeline connecting the pressure regulating element 410, the first valve element 440, and the distribution unit 500 is the second pipeline, i.e., the main pipeline.

[0057] In some specific embodiments, the second conduit includes, but is not limited to, the use of a heating cable.

[0058] Furthermore, when there are multiple second valve elements 450, the multiple second valve elements 450 are arranged in parallel.

[0059] Specifically, the second valve element 450 includes, but is not limited to, ball valves and butterfly valves.

[0060] Preferably, the pipeline connecting the pressure regulating element 410, the second valve element 450, and the buffer unit 600 is a third pipeline.

[0061] In some specific embodiments, the third conduit includes, but is not limited to, the use of a heating cable.

[0062] Specifically, the second and third pipelines share a common section near the pressure regulating element 410, on which a second pressure monitoring element is installed to monitor the pressure of ammonia gas after it has been regulated by the pressure regulating element 410.

[0063] Furthermore, when there are multiple third valve elements 460, the multiple third valve elements 460 are arranged in parallel.

[0064] Specifically, the third valve element 460 includes, but is not limited to, ball valves and butterfly valves.

[0065] Preferably, the pipeline connecting the pressure regulating element 410, the third valve element 460, and the purging unit 800 is a fourth pipeline.

[0066] like Figure 4 As shown, the buffer unit 600 includes a buffer element 610 and a third pressure monitoring element 620, which monitors the internal pressure of the buffer element 610.

[0067] Specifically, the heating unit 300 is attached to the outside of the buffer element 610 to heat the buffer element 610 and prevent the ammonia gas in the buffer element 610 from liquefying.

[0068] Preferably, there are several buffer elements 610, and the several buffer elements 610 are arranged in parallel.

[0069] Furthermore, the third pressure monitoring element 620 is located downstream of the third pipeline, i.e., on the side close to the buffer element 610.

[0070] Furthermore, the number of third pressure monitoring elements 620 is the same as the number of buffer elements 610.

[0071] like Figure 5 As shown, the heating unit 300 includes a first heating unit 310, a second heating unit 320, a third heating unit 330, a heating tape element 340, a first temperature monitoring element 350, a second temperature monitoring element 360, a third temperature monitoring element 370, and a fourth temperature monitoring element 380.

[0072] Specifically, the first heating element 310 is attached to the outside of the liquid storage element 210 for heating.

[0073] Among them, there are several first heating elements 310, and the number is the same as the number of liquid storage elements 210.

[0074] Furthermore, the first temperature monitoring element 350 monitors the temperature of the liquid storage element 210 and transmits the temperature signal to the first controller unit 910.

[0075] Preferably, the first controller unit 910 controls the heating strategy of the first heating element 310 according to the temperature of the liquid storage element 210.

[0076] Specifically, the second heating element 320 is attached to the outside of the standby liquid storage element 220 for heating.

[0077] Among them, there are several second heating elements 320, and the number is the same as the number of spare liquid storage elements 220.

[0078] Furthermore, the second temperature monitoring element 360 monitors the temperature of the backup liquid storage element 220 and transmits the temperature signal to the first controller unit 910.

[0079] Preferably, the first controller unit 910 controls the heating strategy of the second heating element 320 according to the temperature of the backup liquid storage element 220.

[0080] Specifically, the third heating element 330 is attached to the outside of the buffer element 610 for heating.

[0081] Among them, there are several third heating elements 330, and the number is the same as the number of buffer elements 610.

[0082] Furthermore, the third temperature monitoring element 370 monitors the temperature of the buffer element 610 and transmits the temperature signal to the first controller unit 910.

[0083] Preferably, the first controller unit 910 controls the heating strategy of the third heating element 330 based on the temperature of the buffer element 610.

[0084] Specifically, the heating element 340 is externally attached to the system piping for heating.

[0085] The system piping and components include a first piping, a second piping, a third piping, and a fourth piping.

[0086] Furthermore, the fourth temperature monitoring element 380 monitors the temperature of the system piping and transmits the temperature signal to the first controller unit 910.

[0087] Preferably, the first controller unit 910 controls the heating strategy of the heat tracing element 340 according to the temperature of the system pipeline.

[0088] like Figure 6 As shown, the analysis unit 700 includes a first analysis element 710 and a second analysis element 720. The first analysis element 710 is responsible for monitoring the ammonia leakage of the pressure regulating unit 400, and the second analysis element 720 is responsible for monitoring the ammonia leakage of the distribution unit 500.

[0089] The first analysis element 710 and the second analysis element 720 are connected to the third controller element 930 of the control unit.

[0090] A control method for a constant pressure ammonia supply control system: After receiving the temperature feedback from the first temperature monitoring element 350, the first controller element 910 controls the first heating unit 310 to heat the liquid storage element 210 to a specified temperature, so that the liquid ammonia stored in the liquid storage element 210 is vaporized into high-pressure ammonia and flows to the pressure regulating element 410; the first monitoring element 420 monitors the pressure of ammonia entering the pressure regulating element 410, and the second pressure monitoring element 430 monitors the pressure of ammonia after it comes out of the pressure regulating element 410. Under the control of the second controller element 920 and the feedback from the first pressure monitoring element 420 and the second pressure monitoring element 430, the pressure regulating element 410 reduces the pressure of the high-pressure ammonia to a specified low-pressure ammonia. The low-pressure ammonia flows to the distribution unit 500 and the buffer unit 600. After being distributed by the distribution unit 500, the low-pressure ammonia flows to the equipment in use. The heating element 340 heats the first pipeline, the second pipeline, and the third pipeline throughout the process.

[0091] When multiple ammonia-using devices simultaneously consume large amounts of ammonia, the pressure in the second pipeline between the pressure regulating unit 400 and the distribution unit 500 will drop rapidly, causing supply difficulties. At this time, the first controller element 910 of the control unit 900 detects the rapid pressure drop and uses the backup liquid storage element 220 to supply the ammonia. If the pressure still cannot be stabilized at the normal level, the low-pressure ammonia stored in the buffer element 610 will be supplied as an auxiliary, thereby ensuring the pressure in the main pipeline remains stable.

[0092] When there is a sufficient supply of low-pressure ammonia in the second pipeline, the buffer element 610 stops providing auxiliary supply; and ammonia is introduced into the buffer element 610 until the ammonia pressure inside the buffer element 610 is equal to the ammonia pressure in the second pipeline; and under the control of the first controller element 910, the third heating element 330 is controlled to heat the buffer element 610 to prevent the low-pressure ammonia from liquefying.

[0093] When there are multiple liquid storage elements 210, the first controller element 910 will determine the amount of liquid ammonia used in the multiple liquid storage elements 210 based on the weight signals transmitted by the multiple weighing elements 110; based on the remaining amount of liquid ammonia used in the multiple liquid storage elements 210, different heating temperatures will be set for the multiple liquid storage elements 210 to ensure that the liquid ammonia in the multiple liquid storage elements 210 can be used up at the same time for convenient switching and bottle changing.

[0094] When the first weighing element 110 detects that the amount of liquid ammonia used in the liquid storage element 210 is insufficient, the second controller element 920 will control the ammonia source to switch to the backup liquid storage element 220. The backup liquid storage element 220 will then become the liquid storage unit 210. After the original liquid storage unit 210 is changed, it will become the backup liquid storage element 220.

[0095] The third controller element 930 is connected to the first controller 910 and the second controller 920, and receives and operates the data of the entire system for display on the host computer interface and other operation processing.

[0096] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, 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 a process, method, article, or apparatus. Without further limitations, 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 said element.

[0097] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. 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 this application. Therefore, this application 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 claimed herein.

Claims

1. A constant pressure ammonia supply control system, characterized in that, include: A liquid storage unit is used to store liquid ammonia to obtain ammonia gas. A weighing unit, located below the liquid storage unit, is used to detect the remaining amount of liquid ammonia to be used. A heating unit is attached externally to the liquid storage unit and the pipeline to obtain sufficient ammonia evaporation and prevent ammonia from liquefying in the pipeline. A pressure regulating unit is connected to the liquid storage unit via a pipeline to regulate the pressure of ammonia gas inside the pipeline. A distribution unit, which is connected to the pressure regulating unit via a pipeline to form a main pipeline, is used to distribute ammonia to different gas-using equipment and systems. A buffer unit, which is connected to the pressure regulating unit and the distribution unit via a pipeline, is used to stabilize the pressure of the main pipeline between the pressure regulating unit and the distribution unit; An analysis unit, located within the pressure regulating unit and the distribution unit, is used to monitor ammonia leakage. A purging unit, which is connected to the liquid storage unit and the pressure regulating unit through a pipeline, is used to purge impurities in the pressure regulating unit and the pipeline. The control unit is connected to the weighing unit, the liquid storage unit, the heating unit, the purging unit, the pressure regulating unit, the buffer unit, and the distribution unit, respectively, and is used to control the stable operation of the entire system; The liquid storage unit includes at least one liquid storage element and at least one spare liquid storage element; The weighing unit includes a weighing element, which is positioned below the liquid storage element and the backup liquid storage element. The weighing element weighs the liquid storage element and the backup liquid storage element to monitor the remaining amount of liquid ammonia. The control unit includes a first controller element; when there are several liquid storage elements, the first controller element will determine the amount of liquid ammonia used in several liquid storage elements based on the weight signals transmitted by several weighing elements; based on the remaining amount of liquid ammonia used in several liquid storage elements, different heating temperatures will be set for several liquid storage elements to ensure that the liquid ammonia in several liquid storage elements can be used up at the same time for convenient switching and bottle changing.

2. The ammonia constant pressure supply control system as described in claim 1, characterized in that, The liquid storage unit includes: At least one liquid storage element is connected to the pressure regulating unit and the purging unit respectively through pipelines, and is used to store liquid ammonia; At least one backup liquid storage element is provided. The backup liquid storage element is connected to the pressure regulating unit and the purging unit through pipelines. It is used to switch to the backup liquid storage element for ammonia supply when the liquid ammonia in the original liquid storage element is used up, and then switch to the original liquid storage element. The original liquid storage element will be replaced with the backup liquid storage element filled with liquid ammonia after it is used up, i.e., bottle changing operation. The number of backup liquid storage elements is consistent with the number of liquid storage elements.

3. The ammonia constant pressure supply control system as described in claim 2, characterized in that, The heating unit includes: A heating element is externally attached to the liquid storage element, the backup liquid storage element, and the buffer unit; the heating element heats the liquid storage element and the backup liquid storage element to obtain sufficient ammonia evaporation; the heating element heats the buffer unit to prevent ammonia liquefaction within the buffer unit; A heat tracing element is attached to the outside of the pipeline between the liquid storage unit, the pressure regulating unit, the distribution unit, and the buffer unit. The pipeline between the liquid storage unit, the pressure regulating unit, the distribution unit, and the buffer unit is heated to prevent the ammonia gas inside the pipeline from liquefying. At least one temperature monitoring element is placed inside the heating element and the heat tracing element to monitor the temperature of the heating element and the heat tracing element.

4. The ammonia constant pressure supply control system according to claim 3, characterized in that, The voltage regulating unit includes: At least one pressure regulating element is connected to the liquid storage unit, the purging unit, the distribution unit and the buffer unit through pipelines, respectively, for regulating the high-pressure ammonia gas from the liquid storage unit to a relatively low-pressure ammonia gas and delivering it to the distribution unit and the buffer unit; A first pressure monitoring element is disposed in the pipeline between the pressure regulating unit and the liquid storage unit, and is used to monitor the pressure of ammonia gas before pressure regulation. The second pressure monitoring element is disposed in the pipeline between the pressure regulating unit, the buffer unit, and the distribution unit, and is used to monitor the pressure of ammonia gas after pressure regulation.

5. The ammonia constant pressure supply control system according to claim 4, characterized in that, The buffer unit includes: A buffer element is connected to the pressure regulating unit and the distribution unit. The buffer element contains a certain amount of gaseous ammonia to stabilize the pressure of the main pipeline between the pressure regulating unit and the distribution unit. The third pressure monitoring element is located downstream of the pipeline between the buffer element and the pressure regulating unit, and is used to monitor the pressure of ammonia gas stored in the buffer element.

6. The ammonia constant pressure supply control system according to claim 5, characterized in that, The analysis unit includes: The first analytical element is used to monitor ammonia leakage in the pressure regulating unit; The second analytical element is used to monitor ammonia leakage in the distribution unit.

7. The ammonia constant pressure supply control system according to claim 6, characterized in that, The control unit includes: The first controller element controls the heating start-up, heating stop-up, and heating temperature of the heating element and the heating tape element to ensure sufficient ammonia evaporation and prevent liquefaction of ammonia in the buffer element and pipeline. The second controller element controls the liquid storage element, the backup liquid storage element, the pressure regulating element, and the purging unit to provide ammonia gas at a constant pressure and to automate the switching of the liquid storage element to the backup liquid storage element and the replacement of the original liquid storage element. The third controller element receives signals from the first and second analysis elements and is used for emergency handling of ammonia leaks. The third controller element is connected to the first and second controller elements and receives and processes data from the entire system.

8. The ammonia constant pressure supply control system according to claim 7, characterized in that, The liquid storage unit further includes: When the liquid storage unit contains multiple liquid storage elements, the heating unit will heat the multiple liquid storage elements to different degrees under the control of the first controller element, so that the multiple liquid storage elements can be used up at the same time, and then the switching and bottle changing can be performed simultaneously.

9. A control method for an ammonia constant pressure supply control system, characterized in that, Applied to the ammonia constant pressure supply system as described in any one of claims 1-8.

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