Liquid ammonia filling system

Abstract

The application provides a liquid ammonia filling system, which comprises a finished product tank, a nitrogen purging system, a helium pressure maintaining system, a pressure sensor, a liquid ammonia filling container, a gas extraction pump, an exhaust treatment device, an ammonia gas analysis system, a first condensing device, a condensing recovery tank, a second condensing device and a waste liquid tank; the outlet of the nitrogen purging system and the outlet of the helium pressure maintaining system are both communicated with the inlet of the liquid ammonia filling container, the outlet of the liquid ammonia filling container, the inlet of the gas extraction pump and the exhaust treatment device are sequentially communicated; when the ammonia purity in the liquid ammonia filling container is qualified after analysis by the ammonia gas analysis system, the ammonia gas in the liquid ammonia filling container is condensed into liquid ammonia by the first condensing device and then stored in the condensing recovery tank; when the ammonia purity in the liquid ammonia filling container is unqualified after analysis by the ammonia gas analysis system, the ammonia gas in the liquid ammonia filling container is condensed into liquid ammonia by the second condensing device and then stored in the waste liquid tank.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of liquid ammonia filling, in particular to a liquid ammonia filling system, and more particularly to an ultrapure liquid ammonia filling system. BACKGROUND

[0002] Ultrapure ammonia is the main preparation material of microelectronic silicon nitride and gallium nitride mask film, and is an important raw material in the fields of optoelectronics, semiconductors, and light-emitting diode industries. It is widely used in the fields of liquid crystal panels, photovoltaic optical fibers, LEDs, integrated circuits, etc. The purity of ultrapure ammonia has a direct impact on the service life of device products, the electrical and optical properties of materials, and the like. In the field of semiconductors, for example, the purity of ultrapure ammonia is generally required to reach 7N level (i.e., 99.99999% purity) or 9N level (i.e., 99.9999999% purity). Therefore, the production process, filling process, and the like of ultrapure ammonia need to be strictly controlled in terms of impurity pollution and air tightness, so as to ensure that the purity of ultrapure ammonia is qualified.

[0003] After the production of liquid ammonia is completed, the liquid ammonia is generally temporarily stored in a finished product tank, and then the liquid ammonia is filled from the finished product tank into a tank car or a steel cylinder for use by a user. As disclosed in patent CN109723964A, a filling device for methanol or liquid ammonia and a filling method thereof, the current filling process of liquid ammonia generally uses a pump to transport the liquid ammonia in a storage tank into a tank car, and then transports the tail gas (which is generally ammonia gas; during the filling process, the liquid ammonia in the tank car is partially vaporized into ammonia gas) in the tank car to a tail gas treatment adsorption system for adsorption treatment, and then discharged to the atmosphere.

[0004] However, the above method of directly discharging the tail gas in the tank car to the atmosphere after adsorption treatment does not recycle the ammonia gas, which causes waste of ammonia gas. Meanwhile, for use conditions with strict requirements on the purity of liquid ammonia, the above device and method do not perform purging and air tightness detection on the tank car before filling, so as to ensure the purity of the liquid ammonia in the tank car after filling (i.e., the purity of the liquid ammonia in the storage tank is qualified by itself, but the purity of the liquid ammonia after filling is unqualified due to the presence of impurities in the tank car) and the air tightness of the tank car, and there is a risk of unqualified purity of the liquid ammonia after filling and leakage of the liquid ammonia. SUMMARY

[0005] The purpose of the present application is to provide a liquid ammonia filling system, which can perform nitrogen purging and helium pressure maintaining test on a liquid ammonia filling container, so as to ensure the cleanliness and sealing property of the liquid ammonia filling container, thereby ensuring the qualified purity of the liquid ammonia after filling; and can also recycle the ammonia gas in the liquid ammonia filling container, so as to avoid waste of ammonia gas.

[0006] The application provides a liquid ammonia filling system, which comprises a finished product tank, a nitrogen purging system, a helium pressure maintaining system, a pressure sensor, a liquid ammonia filling container, a gas extraction pump, an exhaust treatment device, an ammonia gas analysis system, a first condensing device, a condensing recovery tank, a second condensing device and a waste liquid tank.

[0007] The nitrogen purging system is used for purging the liquid ammonia filling container with nitrogen, and the outlet of the nitrogen purging system is communicated with the inlet of the liquid ammonia filling container; the helium pressure maintaining system is used for pressure maintaining test of the liquid ammonia filling container, and the outlet of the helium pressure maintaining system is communicated with the inlet of the liquid ammonia filling container; the outlet of the liquid ammonia filling container is communicated with the inlet of the gas extraction pump, and the outlet of the gas extraction pump is communicated with the exhaust treatment device.

[0008] The finished product tank is used for storing liquid ammonia, and the outlet of the finished product tank is communicated with the inlet of the liquid ammonia filling container; the outlet of the liquid ammonia filling container is respectively communicated with the inlet of the first condensing device and the inlet of the second condensing device; the outlet of the first condensing device is communicated with the inlet of the condensing recovery tank, and the outlet of the second condensing device is communicated with the inlet of the waste liquid tank.

[0009] The ammonia gas analysis system is used for purity analysis of ammonia gas, and the ammonia gas analysis system is connected with the liquid ammonia filling container; when the ammonia purity in the liquid ammonia filling container is qualified after analysis of the ammonia gas analysis system, the ammonia gas in the liquid ammonia filling container is discharged to the first condensing device, and the ammonia gas is condensed into liquid ammonia by the first condensing device and then stored in the condensing recovery tank; when the ammonia purity in the liquid ammonia filling container is unqualified after analysis of the ammonia gas analysis system, the ammonia gas in the liquid ammonia filling container is discharged to the second condensing device, and the ammonia gas is condensed into liquid ammonia by the second condensing device and then stored in the waste liquid tank.

[0010] Further, the outlet of the finished product tank is communicated with the inlet of the waste liquid tank through a waste liquid pipeline, and the ammonia gas analysis system is also connected with the finished product tank; when the ammonia purity in the finished product tank is qualified after analysis of the ammonia gas analysis system, the liquid ammonia in the finished product tank is filled into the liquid ammonia filling container; when the ammonia purity in the finished product tank is unqualified after analysis of the ammonia gas analysis system, the liquid ammonia in the finished product tank is transported to the waste liquid tank through the waste liquid pipeline.

[0011] Further, the condensing recovery tank is communicated with the inlet of the product tank through a first reflux pipeline, and the ammonia gas analysis system is further connected with the condensing recovery tank; when the ammonia gas analysis system determines that the ammonia purity in the condensing recovery tank is qualified through analysis, the liquid ammonia in the condensing recovery tank is transported into the product tank through the first reflux pipeline.

[0012] Further, the liquid ammonia filling system further comprises a liquid ammonia recovery tank, an inlet of the liquid ammonia recovery tank being communicated with an outlet of the liquid ammonia filling container, the liquid ammonia recovery tank being used for recovering the liquid ammonia remaining in the liquid ammonia filling container before filling.

[0013] Further, the liquid ammonia recovery tank is communicated with the inlet of the product tank through a second reflux pipeline, and the ammonia gas analysis system is further connected with the liquid ammonia recovery tank; when the ammonia gas analysis system determines that the ammonia purity in the liquid ammonia recovery tank is qualified through analysis, the liquid ammonia in the liquid ammonia recovery tank is transported into the product tank through the second reflux pipeline.

[0014] Further, the liquid ammonia filling system further comprises a pressure relief pipeline, one end of the pressure relief pipeline being communicated with the liquid ammonia filling container, and the other end of the pressure relief pipeline being communicated with the inlet of the second condensing device; when the liquid ammonia filling container is over-pressured, the ammonia gas and / or liquid ammonia in the liquid ammonia filling container can be condensed through the second condensing device and then discharged into the waste liquid tank through the pressure relief pipeline.

[0015] Further, a bursting disc is arranged in the pressure relief pipeline; when the pressure in the liquid ammonia filling container reaches the bursting pressure of the bursting disc, the bursting disc can be broken to make the pressure relief pipeline conductive.

[0016] Further, the liquid ammonia filling system further comprises an emergency relief pipeline, the emergency relief pipeline being communicated with the pressure relief pipeline, and a pressure relief valve being arranged on the emergency relief pipeline.

[0017] Further, the exhaust treatment device is an exhaust hood.

[0018] Further, the liquid ammonia filling container comprises a tank truck storage tank, a 47L steel cylinder and a Y cylinder, an inlet of the tank truck storage tank, an inlet of the 47L steel cylinder and an inlet of the Y cylinder are respectively communicated with an outlet of the nitrogen purging system, an outlet of the helium pressure maintaining system and an outlet of the product tank, and an outlet of the tank truck storage tank, an outlet of the 47L steel cylinder and an outlet of the Y cylinder are respectively communicated with an inlet of the air pump, an inlet of the first condensing device and an inlet of the second condensing device; the ammonia gas analysis system is connected with the tank truck storage tank, the 47L steel cylinder and the Y cylinder respectively.

[0019] The liquid ammonia filling system provided by the application has the nitrogen purging system, which can purify the liquid ammonia filling container and the related filling pipeline, thereby ensuring the cleanliness of the liquid ammonia filling container and the purity of the filled liquid ammonia.

[0020] Meanwhile, the ammonia analysis system, the first condensing device, the condensing recovery tank, the second condensing device and the waste liquid tank are arranged, when the ammonia analysis system determines that the ammonia purity in the liquid ammonia filling container is qualified, the ammonia in the liquid ammonia filling container is condensed into liquid ammonia by the first condensing device and stored in the condensing recovery tank, and when the ammonia analysis system determines that the ammonia purity in the liquid ammonia filling container is unqualified, the ammonia in the liquid ammonia filling container is condensed into liquid ammonia by the second condensing device and stored in the waste liquid tank, thereby realizing the recycling of the ammonia in the liquid ammonia filling container, avoiding the waste of ammonia and improving the economy of the system. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 FIG. 1 is a structural schematic diagram of a liquid ammonia filling system in an embodiment of the application.

[0022] Figure 2 FIG. 2 is a structural schematic diagram of a liquid ammonia filling system in another embodiment of the application.

[0023] Figure 3 FIG. 3 is a structural schematic diagram of a liquid ammonia filling system in another embodiment of the application. DETAILED DESCRIPTION

[0024] The specific embodiments of the application are described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the application, but are not used to limit the scope of the application.

[0025] The terms "first", "second", "third", "fourth" and the like in the specification and claims of the application are used to distinguish similar objects, and do not necessarily have to describe a specific order or sequence.

[0026] As Figure 1As shown, the liquid ammonia filling system provided by the embodiment of the present application, in particular, an ultrapure liquid ammonia filling system, has a filling purity requirement of 9N grade (i.e., the purity reaches 99.9999999%; of course, it can also be other grades) for the ultrapure ammonia. The liquid ammonia filling system comprises a product tank 1, a nitrogen purging system 2, a helium pressure maintaining system 3, a pressure sensor 31, a liquid ammonia filling container 4, a gas extraction pump 51, an exhaust treatment device 52, an ammonia gas analysis system 6, a first condensing device 71, a condensing recovery tank 72, a second condensing device 73, and a waste liquid tank 74.

[0027] The nitrogen purging system 2 is used for purging the liquid ammonia filling container 4 with nitrogen (i.e., the nitrogen purging system 2 is used for outputting nitrogen, and the nitrogen purging system 2 can comprise a nitrogen storage tank, a delivery pump, and related valve groups, etc.), and the outlet of the nitrogen purging system 2 is in communication with the inlet of the liquid ammonia filling container 4.

[0028] The helium pressure maintaining system 3 is used for pressure maintaining test of the liquid ammonia filling container 4 (i.e., the helium pressure maintaining system 3 is used for outputting helium, and the helium pressure maintaining system 3 can comprise a helium storage tank, a delivery pump, and related valve groups, etc.), and the outlet of the helium pressure maintaining system 3 is in communication with the inlet of the liquid ammonia filling container 4. The pressure sensor 31 is connected to the liquid ammonia filling container 4 (specifically, the pressure sensor 31 can monitor the pressure in the liquid ammonia filling container 4. On the one hand, during the filling process of the liquid ammonia filling container 4, the pressure sensor 31 can monitor the stability of the pressure in the liquid ammonia filling container 4; on the other hand, during the pressure maintaining test of the helium, the pressure sensor 31 can monitor whether the pressure in the liquid ammonia filling container 4 is reduced, so as to judge the air tightness of the liquid ammonia filling container 4). The outlet of the liquid ammonia filling container 4 is in communication with the inlet of the gas extraction pump 51, and the outlet of the gas extraction pump 51 is in communication with the exhaust treatment device 52; the purged nitrogen and the helium after the pressure maintaining test can be sucked by the gas extraction pump 51 to the exhaust treatment device 52, and then discharged to the atmosphere after being treated by the exhaust treatment device 52.

[0029] The product tank 1 is used for storing liquid ammonia (i.e., the ultrapure liquid ammonia after production and purification is stored in the product tank 1); the outlet of the product tank 1 is in communication with the inlet of the liquid ammonia filling container 4, so as to be able to fill the liquid ammonia in the product tank 1 into the liquid ammonia filling container 4. The outlet of the liquid ammonia filling container 4 (specifically, the ammonia gas outlet of the liquid ammonia filling container 4; during the filling process, the liquid ammonia in the liquid ammonia filling container 4 will be partially vaporized into ammonia gas) is in communication with the inlet of the first condensing device 71 and the inlet of the second condensing device 73, respectively, and the first condensing device 71 and the second condensing device 73 can be evaporative condensers, etc. The outlet of the first condensing device 71 is in communication with the inlet of the condensing recovery tank 72, and the outlet of the second condensing device 73 is in communication with the inlet of the waste liquid tank 74.

[0030] The ammonia analysis system 6 is used for purity analysis of ammonia, to determine the concentration of ammonia, so as to determine whether it reaches the available standard; the ammonia analysis system 6 is connected with the liquid ammonia filling container 4, and the ammonia in the liquid ammonia filling container 4 can enter the ammonia analysis system 6 for purity analysis (it should be noted that the ammonia analysis system 6 can generally only analyze the purity of gaseous ammonia, and cannot analyze the purity of liquid ammonia). When the ammonia analysis system 6 analyzes and determines that the purity of ammonia in the liquid ammonia filling container 4 is qualified, the ammonia in the liquid ammonia filling container 4 is discharged to the first condensing device 71, and the ammonia is condensed into liquid ammonia by the first condensing device 71 and then stored in the condensing recovery tank 72; when the ammonia analysis system 6 analyzes and determines that the purity of ammonia in the liquid ammonia filling container 4 is unqualified, the ammonia in the liquid ammonia filling container 4 is discharged to the second condensing device 73, and the ammonia is condensed into liquid ammonia by the second condensing device 73 and then stored in the waste liquid tank 74. At the same time, the ammonia analysis system 6 can also determine whether the purity of the liquid ammonia in the filled liquid ammonia filling container 4 is qualified.

[0031] Specifically, the liquid ammonia filling system provided by the embodiment can ensure the cleanliness of the liquid ammonia filling container 4, and further ensure the purity of the filled liquid ammonia, by arranging the nitrogen purging system 2 which can purge the liquid ammonia filling container 4 and the related filling pipeline with nitrogen. At the same time, the helium pressure maintaining system 3 can be arranged to perform pressure maintaining test on the liquid ammonia filling container 4 and the related filling pipeline, so as to ensure the sealing property of the liquid ammonia filling container 4, avoid leakage of the liquid ammonia, ensure safety, and further ensure the purity of the filled liquid ammonia (if the liquid ammonia filling container 4 has poor air tightness, external gas may enter the liquid ammonia filling container 4 and introduce impurities).

[0032] At the same time, when the ammonia analysis system 6 analyzes and determines that the purity of ammonia in the liquid ammonia filling container 4 is qualified, the ammonia in the liquid ammonia filling container 4 is condensed into liquid ammonia by the first condensing device 71 and then stored in the condensing recovery tank 72; when the ammonia analysis system 6 analyzes and determines that the purity of ammonia in the liquid ammonia filling container 4 is unqualified, the ammonia in the liquid ammonia filling container 4 is condensed into liquid ammonia by the second condensing device 73 and then stored in the waste liquid tank 74, so as to realize recycling of the ammonia in the liquid ammonia filling container 4, to avoid waste of ammonia and improve the economy of the system.

[0033] As Figure 1As shown, in one embodiment, the outlet of the finished product tank 1 is connected to the inlet of the waste liquid tank 74 via the waste liquid pipeline 11. The ammonia analysis system 6 is also connected to the finished product tank 1 to analyze the purity of the ammonia in the finished product tank 1. When the ammonia analysis system 6 determines that the purity of the ammonia in the finished product tank 1 is qualified, the liquid ammonia in the finished product tank 1 is filled into the liquid ammonia filling container 4; when the ammonia analysis system 6 determines that the purity of the ammonia in the finished product tank 1 is unqualified, the liquid ammonia in the finished product tank 1 is transported to the waste liquid tank 74 via the waste liquid pipeline 11 for recycling.

[0034] Specifically, this embodiment analyzes and judges the ammonia concentration in the finished product tank 1 to ensure that the purity of the liquid ammonia in the finished product tank 1 is qualified, thereby ensuring the qualification of the liquid ammonia concentration in the liquid ammonia filling container 4 after filling. However, existing liquid ammonia filling systems generally do not perform purity analysis and testing on the source of liquid ammonia, and cannot guarantee the qualification of the purity of liquid ammonia after filling.

[0035] As one implementation method, the liquid ammonia stored in waste tank 74 can be used directly in situations where purity requirements are relatively low, or it can be further purified to meet relevant requirements before being refilled. For example... Figure 3 As shown, in another implementation, the ammonia analysis system 6 is also connected to the waste liquid tank 74 to analyze the purity of the ammonia in the waste liquid tank 74, thereby determining the next processing step. For example, if the ammonia purity in the waste liquid tank 74 is high but does not meet the relevant requirements, it can be purified again; if the ammonia purity in the waste liquid tank 74 is low and the impurity content is high, it can be scrapped, etc.

[0036] like Figure 1 As shown, in one embodiment, the condensate recovery tank 72 is connected to the inlet of the finished product tank 1 via the first reflux pipeline 12. The ammonia analysis system 6 is also connected to the condensate recovery tank 72 to analyze the purity of the ammonia in the condensate recovery tank 72. When the ammonia analysis system 6 determines that the purity of the ammonia in the condensate recovery tank 72 is qualified, the liquid ammonia in the condensate recovery tank 72 is transported to the finished product tank 1 via the first reflux pipeline 12 for refilling, thus realizing the reuse of ammonia. When the ammonia analysis system 6 determines that the purity of the ammonia in the condensate recovery tank 72 is unqualified, the liquid ammonia in the condensate recovery tank 72 can be purified again, or it can be used directly in situations where the purity requirement is relatively low.

[0037] like Figure 1 As shown, in one embodiment, the liquid ammonia filling system also includes a liquid ammonia recovery tank 8. The inlet of the liquid ammonia recovery tank 8 is connected to the outlet of the liquid ammonia filling container 4. The liquid ammonia recovery tank 8 is used to recover the liquid ammonia remaining in the liquid ammonia filling container 4 before filling.

[0038] Specifically, before the liquid ammonia filling container 4 is filled, there may be some liquid ammonia (i.e. the liquid ammonia not used up) remaining in the liquid ammonia filling container 4. If the remaining liquid ammonia is mixed with the newly filled liquid ammonia, the liquid ammonia may be contaminated, so that the purity of the liquid ammonia is unqualified. The present embodiment sets the liquid ammonia recovery tank 8, and the remaining liquid ammonia in the liquid ammonia filling container 4 is recovered to the liquid ammonia recovery tank 8 before the liquid ammonia filling container 4 is filled, so as to avoid the remaining liquid ammonia from causing pollution, and at the same time, avoid the waste of liquid ammonia.

[0039] As shown in Figure 2 As another embodiment, the liquid ammonia recovery tank 8 is connected to the inlet of the product tank 1 through a second reflux pipeline 13, and the ammonia gas analysis system 6 is also connected to the liquid ammonia recovery tank 8 to analyze the purity of the ammonia in the liquid ammonia recovery tank 8. When the ammonia gas analysis system 6 determines that the purity of the ammonia in the liquid ammonia recovery tank 8 is qualified through analysis, the liquid ammonia in the liquid ammonia recovery tank 8 is transported to the product tank 1 through the second reflux pipeline 13 for repeated filling, so as to realize the reuse of the ammonia. When the ammonia gas analysis system 6 determines that the purity of the ammonia in the liquid ammonia recovery tank 8 is unqualified through analysis, the liquid ammonia in the liquid ammonia recovery tank 8 can be purified again, or directly used in a place where the purity requirement is relatively low.

[0040] As shown in Figure 1 As an embodiment, the liquid ammonia filling system further comprises a pressure relief pipeline 53, one end of the pressure relief pipeline 53 is connected to the liquid ammonia filling container 4, and the other end of the pressure relief pipeline 53 is connected to the inlet of the second condensing device 73. When the liquid ammonia filling container 4 is over-pressured, the ammonia gas and / or liquid ammonia in the liquid ammonia filling container 4 can be condensed by the second condensing device 73 through the pressure relief pipeline 53 and then discharged into the waste liquid tank 74, so as to maintain the stability of the pressure of the liquid ammonia filling container 4 and avoid the risk of over-pressurization of the liquid ammonia filling container 4 (especially during the filling process).

[0041] As shown in Figure 1 As an embodiment, the pressure relief pipeline 53 is provided with a rupture disc 54. When the pressure in the liquid ammonia filling container 4 reaches the burst pressure of the rupture disc 54, the rupture disc 54 can be broken to make the pressure relief pipeline 53 conductive. That is, when the pressure in the liquid ammonia filling container 4 does not reach the burst pressure of the rupture disc 54, the rupture disc 54 will not be broken, and at this time, the pressure relief pipeline 53 is disconnected, that is, no pressure relief will be performed. When the pressure in the liquid ammonia filling container 4 reaches the burst pressure of the rupture disc 54, the rupture disc 54 is broken, and the pressure relief pipeline 53 is conductive to perform pressure relief. At the same time, the reason why the pressure relief pipeline 53 is provided with the rupture disc 54 instead of a pressure relief valve is that the sensitivity of the rupture disc 54 is higher than that of the pressure relief valve (the pressure relief valve has a certain hysteresis), so as to more accurately control the pressure relief pressure of the liquid ammonia filling container 4.

[0042] As shown in Figure 1As shown, as an embodiment, the liquid ammonia filling system further comprises an emergency relief pipeline 55, which is in communication with the pressure relief pipeline 53, and is provided with a pressure relief valve 56; when the pressure in the liquid ammonia filling container 4 is relatively large, and the pressure relief pipeline 53 cannot relieve the pressure through the second condensing device 73 and the waste liquid tank 74 in time, at this time, the pressure relief valve 56 is opened to relieve the pressure through the emergency relief pipeline 55. However, the existing liquid ammonia filling system generally does not provide the pressure relief pipeline, and thus cannot guarantee the safety.

[0043] As shown in the figure, Figure 1 As an embodiment, the exhaust treatment device 52 is an exhaust hood, which can purify the exhaust, and has a relatively low cost.

[0044] As shown in the figure, Figure 1 As an embodiment, the first control valve 75 is provided on the pipeline between the outlet of the liquid ammonia filling container 4 and the inlet of the first condensing device 71, and the second control valve 76 is provided on the pipeline between the outlet of the liquid ammonia filling container 4 and the inlet of the second condensing device 73. When the ammonia gas analysis system 6 analyzes and determines that the ammonia purity in the liquid ammonia filling container 4 is qualified, the first control valve 75 is opened, and the second control valve 76 is closed, so that the ammonia gas in the liquid ammonia filling container 4 is discharged to the first condensing device 71, and the ammonia gas is condensed into liquid ammonia by the first condensing device 71 and stored in the condensing recovery tank 72; when the ammonia gas analysis system 6 analyzes and determines that the ammonia purity in the liquid ammonia filling container 4 is unqualified, the second control valve 76 is opened, and the first control valve 75 is closed, so that the ammonia gas in the liquid ammonia filling container 4 is discharged to the second condensing device 73, and the ammonia gas is condensed into liquid ammonia by the second condensing device 73 and stored in the waste liquid tank 74.

[0045] As shown in the figure, Figure 1 As an embodiment, the liquid ammonia filling container 4 comprises a tank truck storage tank 41, a 47L steel cylinder 42 and a Y cylinder 43 on the tank truck, the inlet of the tank truck storage tank 41, the inlet of the 47L steel cylinder 42 and the inlet of the Y cylinder 43 are respectively in communication with the outlet of the nitrogen purging system 2, the outlet of the helium pressure maintaining system 3 and the outlet of the finished product tank 1, and the outlet of the tank truck storage tank 41, the outlet of the 47L steel cylinder 42 and the outlet of the Y cylinder 43 are respectively in communication with the inlet of the air pump 51, the inlet of the first condensing device 71 and the inlet of the second condensing device 73. The ammonia gas analysis system 6 is connected to the tank truck storage tank 41, the 47L steel cylinder 42 and the Y cylinder 43, respectively, and the tank truck storage tank 41, the 47L steel cylinder 42 and the Y cylinder 43 are respectively provided with a pressure sensor 31. At the same time, the outlet of the tank truck storage tank 41, the outlet of the 47L steel cylinder 42 and the outlet of the Y cylinder 43 are respectively in communication with the liquid ammonia recovery tank 8 and the pressure relief pipeline 53. Of course, in other embodiments, the liquid ammonia filling container 4 can also be other containers.

[0046] As an embodiment, the number of product tanks 1 is two (only one product tank 1 is shown in the figure), one of which is connected to the tanker storage tank 41 for filling the tanker storage tank 41 with liquid ammonia, and the other is connected to the 47L steel cylinder 42 and the Y cylinder 43 respectively for filling the 47L steel cylinder 42 and the Y cylinder 43 with liquid ammonia. Since the volume of the tanker storage tank 41 is much larger than that of the 47L steel cylinder 42 and the Y cylinder 43, the two product tanks 1 can be used for filling respectively, and the two product tanks 1 can be set to different sizes.

[0047] As an embodiment, corresponding control valves (not shown in the figure) and pumps (not shown in the figure) are also provided on each pipeline.

[0048] As an embodiment, the working process of the liquid ammonia filling system is as follows:

[0049] 1. Before filling the liquid ammonia, the residual liquid ammonia in the liquid ammonia filling container 4 is recovered to the liquid ammonia recovery tank 8, so as to avoid pollution caused by the residual liquid ammonia.

[0050] Then, the liquid ammonia filling container 4 and the related pipelines are nitrogen purged: when purging with nitrogen, the valve (not shown in the figure) between the outlet of the nitrogen purging system 2 and the inlet of the liquid ammonia filling container 4 is opened, and the nitrogen in the nitrogen purging system 2 enters the liquid ammonia filling container 4 for purging, so as to ensure the cleanliness of the liquid ammonia filling container 4; after purging is completed, the nitrogen in the liquid ammonia filling container 4 is sucked by the suction pump 51 to the exhaust treatment device 52, and then discharged to the atmosphere after being treated by the exhaust treatment device 52.

[0051] Then, the liquid ammonia filling container 4 and the related pipelines are helium pressure maintaining tested: the valve (not shown in the figure) between the outlet of the helium pressure maintaining system 3 and the inlet of the liquid ammonia filling container 4 is opened, and the helium in the helium pressure maintaining system 3 enters the liquid ammonia filling container 4, then the inlet and outlet valves of the liquid ammonia filling container 4 are closed, and the pressure is maintained for a period of time (for example, 24 hours), and the pressure sensor 31 is used to monitor whether the pressure in the liquid ammonia filling container 4 decreases, if not, it indicates that the liquid ammonia filling container 4 has good airtightness. After the pressure maintaining test is completed, the helium in the liquid ammonia filling container 4 is sucked by the suction pump 51 to the exhaust treatment device 52, and then discharged to the atmosphere after being treated by the exhaust treatment device 52.

[0052] Then, the liquid ammonia filling container 4 and the related pipelines are nitrogen purged again by using the nitrogen purging system 2, so as to discharge the residual helium and other impurities in the liquid ammonia filling container 4 and the related pipelines, and ensure the cleanliness of the liquid ammonia filling container 4. The nitrogen purging process is the same as described above, and is not described here.

[0053] 2. After the nitrogen purging and pressure holding tests are completed, the ammonia in the finished product tank 1 is analyzed for purity using the ammonia analysis system 6. If the ammonia analysis system 6 determines that the purity of the ammonia in the finished product tank 1 is qualified, the liquid ammonia in the finished product tank 1 is filled into the liquid ammonia filling container 4; if the ammonia analysis system 6 determines that the purity of the ammonia in the finished product tank 1 is unqualified, the liquid ammonia in the finished product tank 1 is transported to the waste liquid tank 74 through the waste liquid pipeline 11 for recovery.

[0054] During the filling process, the ammonia in the liquid ammonia filling container 4 is analyzed for purity using an ammonia analysis system 6. When the ammonia analysis system 6 determines that the purity of the ammonia in the liquid ammonia filling container 4 is up to standard, the ammonia in the liquid ammonia filling container 4 is discharged to the first condensation device 71, where the ammonia is condensed into liquid ammonia and stored in the condensation recovery tank 72. When the ammonia analysis system 6 determines that the purity of the ammonia in the liquid ammonia filling container 4 is not up to standard, the ammonia in the liquid ammonia filling container 4 is discharged to the second condensation device 73, where the ammonia is condensed into liquid ammonia and stored in the waste liquid tank 74.

[0055] Meanwhile, the ammonia in the condensation recovery tank 72 is analyzed for purity using the ammonia analysis system 6. When the ammonia analysis system 6 determines that the purity of the ammonia in the condensation recovery tank 72 is qualified, the liquid ammonia in the condensation recovery tank 72 is transported to the finished product tank 1 through the first return pipeline 12 for refilling, so as to realize the reuse of ammonia.

[0056] The liquid ammonia filling system provided in this embodiment of the invention includes a nitrogen purging system 2. This system purges the liquid ammonia filling container 4 and related filling pipelines with nitrogen, ensuring the cleanliness of the container and consequently guaranteeing the purity of the filled liquid ammonia. Simultaneously, a helium pressure holding system 3 performs pressure holding tests on the container and pipelines, ensuring the container's airtightness, preventing leakage, guaranteeing safety, and further ensuring the purity of the filled liquid ammonia. Furthermore, the purged nitrogen and the helium from the pressure holding test are pumped by a vacuum pump 51 to an exhaust treatment device 52, where they are treated to meet standards before being released into the atmosphere, thus preventing environmental pollution.

[0057] Meanwhile, by setting the ammonia gas analysis system 6, the first condensing device 71, the condensing recovery tank 72, the second condensing device 73 and the waste liquid tank 74, when the ammonia gas analysis system 6 analyzes and judges that the ammonia purity in the liquid ammonia filling container 4 is qualified, the ammonia gas in the liquid ammonia filling container 4 is condensed into liquid ammonia by the first condensing device 71 and stored in the condensing recovery tank 72; when the ammonia gas analysis system 6 analyzes and judges that the ammonia purity in the liquid ammonia filling container 4 is unqualified, the ammonia gas in the liquid ammonia filling container 4 is condensed into liquid ammonia by the second condensing device 73 and stored in the waste liquid tank 74, thereby realizing the recycling of the ammonia gas in the liquid ammonia filling container 4, avoiding the waste of ammonia gas and improving the economy of the system.

[0058] The above merely provides a specific implementation of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A liquid ammonia filling system characterized by, The system comprises a finished product tank (1), a nitrogen purging system (2), a helium pressure maintaining system (3), a pressure sensor (31), an ammonia liquid filling container (4), a gas extraction pump (51), an exhaust gas treatment device (52), an ammonia gas analysis system (6), a first condensing device (71), a condensing recovery tank (72), a second condensing device (73) and a waste liquid tank (74); The nitrogen purging system (2) is used for purging the ammonia liquid filling container (4) with nitrogen, and the outlet of the nitrogen purging system (2) is communicated with the inlet of the ammonia liquid filling container (4); the helium pressure maintaining system (3) is used for pressure maintaining test of the ammonia liquid filling container (4), and the outlet of the helium pressure maintaining system (3) is communicated with the inlet of the ammonia liquid filling container (4), and the pressure sensor (31) is connected with the ammonia liquid filling container (4); the outlet of the ammonia liquid filling container (4) is communicated with the inlet of the gas extraction pump (51), and the outlet of the gas extraction pump (51) is communicated with the exhaust gas treatment device (52); The finished product tank (1) is used for storing liquid ammonia, and the outlet of the finished product tank (1) is communicated with the inlet of the ammonia liquid filling container (4), the outlet of the ammonia liquid filling container (4) is respectively communicated with the inlet of the first condensing device (71) and the inlet of the second condensing device (73), the outlet of the first condensing device (71) is communicated with the inlet of the condensing recovery tank (72), and the outlet of the second condensing device (73) is communicated with the inlet of the waste liquid tank (74); The ammonia gas analysis system (6) is used for purity analysis of ammonia gas, and the ammonia gas analysis system (6) is connected with the ammonia liquid filling container (4); when the ammonia gas analysis system (6) judges that the purity of ammonia in the ammonia liquid filling container (4) is qualified through analysis, the ammonia gas in the ammonia liquid filling container (4) is discharged to the first condensing device (71), and the ammonia gas is condensed into liquid ammonia by the first condensing device (71) and stored in the condensing recovery tank (72); when the ammonia gas analysis system (6) judges that the purity of ammonia in the ammonia liquid filling container (4) is unqualified through analysis, the ammonia gas in the ammonia liquid filling container (4) is discharged to the second condensing device (73), and the ammonia gas is condensed into liquid ammonia by the second condensing device (73) and stored in the waste liquid tank (74); The condensing recovery tank (72) is communicated with the inlet of the finished product tank (1) through a first reflux pipeline (12), and the ammonia gas analysis system (6) is also connected with the condensing recovery tank (72); when the ammonia gas analysis system (6) judges that the purity of ammonia in the condensing recovery tank (72) is qualified through analysis, the liquid ammonia in the condensing recovery tank (72) is transported to the finished product tank (1) through the first reflux pipeline (12).

2. The liquid ammonia filling system of claim 1, wherein, The outlet of the finished product tank (1) is communicated with the inlet of the waste liquid tank (74) through a waste liquid pipeline (11), and the ammonia gas analysis system (6) is also connected with the finished product tank (1); when the ammonia purity in the finished product tank (1) is determined to be qualified by the ammonia gas analysis system (6), the liquid ammonia in the finished product tank (1) is filled into the liquid ammonia filling container (4); when the ammonia purity in the finished product tank (1) is determined to be unqualified by the ammonia gas analysis system (6), the liquid ammonia in the finished product tank (1) is transported into the waste liquid tank (74) through the waste liquid pipeline (11).

3. The liquid ammonia filling system of claim 1, wherein, The liquid ammonia filling system further comprises a liquid ammonia recovery tank (8), and the inlet of the liquid ammonia recovery tank (8) is communicated with the outlet of the liquid ammonia filling container (4); the liquid ammonia recovery tank (8) is used for recovering the residual liquid ammonia in the liquid ammonia filling container (4) before filling.

4. The liquid ammonia filling system of claim 3, wherein, The liquid ammonia recovery tank (8) is communicated with the inlet of the finished product tank (1) through a second reflux pipeline (13), and the ammonia gas analysis system (6) is also connected with the liquid ammonia recovery tank (8); when the ammonia purity in the liquid ammonia recovery tank (8) is determined to be qualified by the ammonia gas analysis system (6), the liquid ammonia in the liquid ammonia recovery tank (8) is transported into the finished product tank (1) through the second reflux pipeline (13).

5. The liquid ammonia filling system of claim 1, wherein, The liquid ammonia filling system further comprises a pressure relief pipeline (53), one end of the pressure relief pipeline (53) is communicated with the liquid ammonia filling container (4), and the other end of the pressure relief pipeline (53) is communicated with the inlet of the second condensing device (73); when the liquid ammonia filling container (4) is over-pressured, the ammonia gas and / or liquid ammonia in the liquid ammonia filling container (4) can be condensed by the second condensing device (73) and then discharged into the waste liquid tank (74) through the pressure relief pipeline (53).

6. The liquid ammonia filling system of claim 5, wherein, An explosion disc (54) is arranged in the pressure relief pipeline (53); when the pressure in the liquid ammonia filling container (4) reaches the burst pressure of the explosion disc (54), the explosion disc (54) can be broken to make the pressure relief pipeline (53) conductive.

7. The liquid ammonia filling system of claim 5, wherein, The liquid ammonia filling system further comprises an emergency relief pipeline (55), the emergency relief pipeline (55) is communicated with the pressure relief pipeline (53), and a pressure relief valve (56) is arranged on the emergency relief pipeline (55).

8. The liquid ammonia filling system of claim 1, wherein, The exhaust treatment device (52) is an exhaust hood.

9. The liquid ammonia filling system of any one of claims 1-8, wherein, The liquid ammonia filling container (4) comprises a tank truck storage tank (41), a 47L steel cylinder (42) and a Y cylinder (43), the inlet of the tank truck storage tank (41), the inlet of the 47L steel cylinder (42) and the inlet of the Y cylinder (43) are communicated with the outlet of the nitrogen gas purging system (2), the outlet of the helium gas pressure maintaining system (3) and the outlet of the finished product tank (1) respectively, the outlet of the tank truck storage tank (41), the outlet of the 47L steel cylinder (42) and the outlet of the Y cylinder (43) are communicated with the inlet of the air pump (51), the inlet of the first condensing device (71) and the inlet of the second condensing device (73) respectively; the ammonia gas analysis system (6) is connected with the tank truck storage tank (41), the 47L steel cylinder (42) and the Y cylinder (43) respectively.

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