System and method for online removal of ammonium salts on trays of a stabilizing column

Abstract

The present invention discloses a system and method for online removing ammonium salts on the trays of a stabilizing tower, belonging to the technical field of petroleum refining. The technical solution is as follows: It includes a re-contact tank, a stabilizing tower, and a stabilizing tower reflux tank. The re-contact tank and the stabilizing tower are connected through a stabilizing tower feed pipeline, and a stabilizing tower feed heat exchanger and a feed control valve are arranged on the stabilizing tower feed pipeline; the stabilizing tower and the stabilizing tower reflux tank are connected through a stabilizing tower reflux tank feed pipeline, and a stabilizing tower overhead air cooler and a stabilizing tower overhead cooler are arranged on the stabilizing tower reflux tank feed pipeline; a stabilizing tower reflux pump and a reflux control valve are arranged on the stabilizing tower reflux tank discharge pipeline; it also includes a water injection pipeline 1 arranged on the stabilizing tower feed pipeline, a water injection pipeline 2 arranged on the stabilizing tower reflux tank discharge pipeline, and a water injection pipeline 3 arranged on the pipeline between the stabilizing tower and the stabilizing tower overhead air cooler. The present invention conducts online water injection to wash the tower under the normal startup state of the device to remove the crystallized ammonium salts on the trays.

Description

Technical Field

[0001] The present invention belongs to the technical field of petroleum refining, and particularly relates to a system and method for online removal of ammonium salts on the trays of a stabilizer tower. Background Art

[0002] The reforming unit consists of a pre-hydrogenation unit and a reforming unit, and the processing raw material is straight-run naphtha; the main reforming products are high-octane gasoline, hydrogen, liquefied gas, etc.; as the main equipment for separating gasoline and liquefied gas in the reforming unit products, the separation effect of the trays of the stabilizer tower determines whether the quality of the liquefied gas product is qualified. Due to the crystallization of ammonium salts on the trays of the stabilizer tower in the reforming unit, the floating valves are stuck and cannot effectively rise and fall, the tray efficiency is reduced, and the quality of the liquefied gas is unqualified. In the prior art, ammonium salts are dissolved with water in an offline state to achieve the purpose of treating ammonium salts, and shutdown will seriously affect production efficiency and increase production costs. Therefore, it is necessary to develop an online system and process for removing ammonium salts on the trays by adjusting the operating parameters of the stabilizer tower to solve the problem of liquefied gas quality. Summary of the Invention

[0003] The present invention provides a system and method for online removal of ammonium salts on the trays of a stabilizer tower, which can perform online water injection to wash the tower and remove the crystallized ammonium salts on the trays under the normal startup state of the device.

[0004] The technical solution of the present invention is as follows:

[0005] In a first aspect, a system for online removal of ammonium salts on the trays of a stabilizer tower is disclosed, which is characterized in that it includes a re-contact tank, a stabilizer tower, a stabilizer tower reflux tank, and a controller. The re-contact tank and the stabilizer tower are connected through a stabilizer tower feed pipeline, and a stabilizer tower feed heat exchanger and a feed control valve are arranged on the stabilizer tower feed pipeline. A pressure sensor and a first temperature sensor are arranged at the top of the stabilizer tower, a second temperature sensor is arranged at the bottom of the stabilizer tower, and a liquid level sensor is arranged in the stabilizer tower reflux tank. The feed control valve, the pressure sensor, the liquid level sensor, the first temperature sensor, and the second temperature sensor are all electrically connected to the controller; the stabilizer tower is connected to the stabilizer tower reflux tank through a stabilizer tower reflux tank feed pipeline, and a stabilizer tower top air cooler and a stabilizer tower top cooler are arranged on the stabilizer tower reflux tank feed pipeline; the stabilizer tower reflux tank is communicated with the stabilizer tower reflux feed inlet through a stabilizer tower reflux tank discharge pipeline, and a liquid hydrocarbon discharge pipeline, a stabilizer tower reflux pump, and a reflux control valve are arranged on the stabilizer tower reflux tank discharge pipeline. The reflux control valve is electrically connected to the controller; the bottom of the stabilizer tower is also connected with a stabilizer tower bottom reboiler and a stabilized gasoline outlet, and the stabilized gasoline outlet is connected with a stabilized gasoline discharge pipeline; it also includes a first water injection pipeline arranged on the stabilizer tower feed pipeline, a second water injection pipeline arranged on the stabilizer tower reflux tank discharge pipeline, and a third water injection pipeline arranged on the pipeline between the stabilizer tower and the stabilizer tower top air cooler.

[0006] Preferably, the first water injection pipeline is arranged on the pipeline between the re - contact tank and the feed - heat exchanger of the stabilizer column, the second water injection pipeline is arranged before the reflux control valve, and the third water injection pipeline is arranged on the pipeline between the stabilizer column and the air cooler at the top of the stabilizer column.

[0007] Preferably, orifice plates are provided in the first water injection pipeline, the second water injection pipeline and the third water injection pipeline.

[0008] In a second aspect, a method for online removing ammonium salts on the trays of a stabilizer column using the above - mentioned system is disclosed, which is divided into two steps: intermittent water injection and continuous water injection;

[0009] 1) Intermittent water injection:

[0010] Water is injected into the trays of the stabilizer column through the first water injection pipeline in stages. Each time, water is injected for one minute. Before water injection, the pressure is ensured to be stable. The injected water flows into the stabilizer column reflux drum along the feed pipeline of the stabilizer column reflux drum. When the water level in the stabilizer column reflux drum reaches the interface level, water is drained through the water pocket of the stabilizer column reflux drum. Water samples are taken from the water pocket of the stabilizer column reflux drum for analysis to detect the ammonium salt content in the water. When the ammonium salt content no longer increases, water injection stops;

[0011] 2) Continuous water injection:

[0012] a. Water is injected into the trays of the stabilizer column through the first water injection pipeline. During the water injection process, the pressure is ensured to be stable. The injected water flows into the stabilizer column reflux drum along the feed pipeline of the stabilizer column reflux drum. When the water level in the stabilizer column reflux drum reaches the interface level, water is drained through the water pocket of the stabilizer column reflux drum. Water samples are taken from the water pocket of the stabilizer column reflux drum for analysis to detect the ammonium salt content in the water;

[0013] b. When the water level in the stabilizer column reflux drum reaches the interface level, the first water injection pipeline stops water injection. Water is injected into the stabilizer column through the second water injection pipeline. The chloride ion content in the stabilizer column reflux drum is detected. When the chloride ion content no longer rises, water is injected into the air cooler at the top of the stabilizer column through the third water injection pipeline to clean the ammonium salts in the internal tubes of the air cooler (501) at the top of the stabilizer column;

[0014] c. The exhaust gas volume at the top of the stabilizer column (2) is detected. When the exhaust gas volume rises above 400 Nm 3 / h, both the second water injection pipeline and the third water injection pipeline stop water injection, and the system operates normally for 1 h;

[0015] d. Samples of the bottom product of the stabilizer column are taken for detection. When the product is qualified, the tower washing stops. If the product is still unqualified, repeat step 2).

[0016] Preferably, in step 1), before injecting water into the trays of the stabilizer column through the first water injection pipeline, the pressure at the top of the stabilizer column is controlled to be below 1.0 Mpa, and the temperature at the bottom of the stabilizer column is controlled to be below 180 °C.

[0017] Preferably, in step 1), if the top pressure of the stabilization tower exceeds 1.30 MPa or the top temperature exceeds 70° C., water injection is stopped; if the reflux pump of the stabilization tower is evacuated, water injection is stopped.

[0018] Preferably, in step 2), before injecting water into the tray of the stabilizing tower through the water injection pipeline 1, the top pressure of the stabilizing tower is controlled to drop below 1.0 MPa, and the bottom temperature of the stabilizing tower is controlled to drop below 160°C.

[0019] Preferably, in step 2), if the top pressure of the stabilization tower exceeds 1.25 MPa or the top temperature exceeds 70° C., water injection is stopped; if the reflux pump of the stabilization tower is evacuated, water injection is stopped.

[0020] Preferably, the water pressure of water injection pipeline one, water injection pipeline two and water injection pipeline three is greater than 1.5 MPa.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The present invention can perform online water injection and tower washing to remove the ammonium salt crystallized on the tower plate when the device is in normal operation; 2. The first water injection pipeline is arranged before the feed heat exchanger of the stabilizing tower, and is used to clean the ammonium salt on the lower tower plate of the feed inlet of the stabilizing tower; the second water injection pipeline is arranged before the reflux control valve, and is used to clean the ammonium salt on the upper tower plate of the feed inlet of the stabilizing tower; the third water injection pipeline is arranged on the pipeline between the stabilizing tower and the air cooler at the top of the stabilizing tower, and is used to clean the internal tube bundle of the air cooler at the top of the stabilizing tower. ammonium salt in the water; 3. Before injecting water into the water injection pipeline 1, strictly control the top pressure of the stabilizing tower to drop to 1.0Mpa, pay close attention to the top pressure of the tower to prevent tower overpressure, and reduce the bottom temperature of the stabilizing tower to below 180℃; before injecting water into the water injection pipeline 2, control the top pressure of the stabilizing tower to drop to below 1.0Mpa, and the bottom temperature of the stabilizing tower to drop to below 160℃ to ensure the normal operation of the system; 4. Water injection pipelines 1, 2 and 3 are all equipped with limited flow orifice plates to prevent excessive water from washing away the tower plates. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of the system for online removal of ammonium salts on the trays of a stabilization tower according to the present invention.

[0024] In the figure, 1 is the re - contact tank; 2 is the stabilizer tower; 3 is the stabilizer reflux drum; 4 is the stabilizer feed pipeline; 401 is the stabilizer feed heat exchanger; 402 is the feed control valve; 5 is the stabilizer reflux drum feed pipeline; 501 is the air cooler on top of the stabilizer tower; 502 is the cooler on top of the stabilizer tower; 6 is the stabilizer reflux drum discharge pipeline; 601 is the stabilizer reflux pump; 602 is the reflux control valve; 7 is the stabilizer reflux feed inlet; 8 is the reboiler at the bottom of the stabilizer tower; 9 is the stabilized gasoline outlet; 10 is the stabilized gasoline discharge pipeline; 11 is the first water injection pipeline; 12 is the second water injection pipeline; 13 is the third water injection pipeline; 14 is the liquid hydrocarbon discharge pipeline. Detailed implementation manners Embodiment

[0025] An on - line ammonium salt removal system for the trays of a stabilizer tower, comprising a re - contact tank 1, a stabilizer tower 2 and a stabilizer reflux drum 3. The re - contact tank 1 and the stabilizer tower 2 are connected through a stabilizer feed pipeline 4. A stabilizer feed heat exchanger 401 and a feed control valve 402 are arranged on the stabilizer feed pipeline 4. A pressure sensor and a first temperature sensor are arranged at the top of the stabilizer tower 2, and a second temperature sensor is arranged at the bottom of the stabilizer tower 2. A liquid level sensor is arranged in the stabilizer reflux drum 3 to monitor the interface level change in the stabilizer reflux drum 3. The feed control valve 402, the pressure sensor, the liquid level sensor, the first temperature sensor and the second temperature sensor are all electrically connected to a controller; The stabilizer tower 2 and the stabilizer reflux drum 3 are connected through a stabilizer reflux drum feed pipeline 5. An air cooler on top of the stabilizer tower 501 and a cooler on top of the stabilizer tower 502 are arranged on the stabilizer reflux drum feed pipeline 5; The stabilizer reflux drum 3 communicates with the stabilizer reflux feed inlet 7 through a stabilizer reflux drum discharge pipeline 6. A liquid hydrocarbon discharge pipeline 14, a stabilizer reflux pump 601 and a reflux control valve 602 are arranged on the stabilizer reflux drum discharge pipeline 6. The reflux control valve 602 is electrically connected to the controller; A reboiler at the bottom of the stabilizer tower 8 and a stabilized gasoline outlet 9 are also connected to the bottom of the stabilizer tower 2. The stabilized gasoline outlet 9 is connected to a stabilized gasoline discharge pipeline 10; It also includes a first water injection pipeline 11 arranged on the stabilizer feed pipeline 4, a second water injection pipeline 12 arranged on the stabilizer reflux drum discharge pipeline 6 and a third water injection pipeline 13 arranged on the pipeline between the stabilizer tower 2 and the air cooler on top of the stabilizer tower 501; The first water injection pipeline 11 is arranged on the pipeline between the re - contact tank 1 and the stabilizer feed heat exchanger 401, the second water injection pipeline 12 is arranged before the reflux control valve 602, and the third water injection pipeline 13 is arranged on the pipeline between the stabilizer tower 2 and the air cooler on top of the stabilizer tower 501; Orifice plates are arranged on the first water injection pipeline 11, the second water injection pipeline 12 and the third water injection pipeline 13, and the aperture of the orifice on the orifice plate is 2 mm.

[0026] The reforming reaction product is mixed with the hydrogen at the outlet of the supercharger in the re-contact tank 1, and a high degree of separation of hydrogen and mixed components such as gasoline and liquefied gas is achieved in the re-contact tank 1. The separated gasoline, liquefied gas and other components enter the stabilization tower 2 after heat exchange through the stabilization tower feed heat exchanger 401 along the stabilization tower feed pipeline 4, and are efficiently separated through the tower plate in the stabilization tower 2. When the system operates normally, the tower top temperature is 60-65°C. The gas at the top of the stabilization tower 2 is condensed by the stabilization tower top air cooler 501 and the stabilization tower top cooler 502 and enters the stabilization tower reflux tank 3. Part of the non-condensable gas in the stabilization tower reflux tank 3 is sent out of the device through the top of the stabilization tower reflux tank 3. The liquefied gas after condensation in the stabilization tower reflux tank 3 is sent out of the device and refluxed through the liquid hydrocarbon discharge pipeline 14, the stabilization tower reflux pump 601 and the reflux control valve 602 respectively. The stabilized gasoline at the bottom of the stabilization tower 2 is sent out of the device through the stabilization gasoline outlet 9 and the stabilization gasoline discharge pipeline 10.

[0027] According to the explanation of the above-mentioned system and working process for online removal of ammonium salts on the trays of the stabilizing tower, a method for online removal of ammonium salts on the trays of the stabilizing tower is provided on the basis of the system for online removal of ammonium salts on the trays of the stabilizing tower. The removal of ammonium salts is carried out under the condition that the system is operating normally. The method for online removal of ammonium salts on the trays of the stabilizing tower is divided into two steps: intermittent water injection and continuous water injection:

[0028] 1) Intermittent water injection:

[0029] The pressure at the top of stabilizing tower 2 is released by adjusting the pressure control valve to release the pressure, so that the pressure at the top of stabilizing tower 2 drops to below 1.0Mpa. The bottom temperature of stabilizing tower 2 is controlled to drop to below 180°C by the reboiler 8 at the bottom of stabilizing tower 2. Water is injected into the tower plate of stabilizing tower 2 through the water injection pipeline 11. The water injection is carried out in stages for one minute each time. The top pressure of stabilizing tower 2 is closely monitored to prevent overpressure of stabilizing tower 2. If overpressure occurs, the water injection is stopped. The deoxygenated water injected through the water injection pipeline 11 flows into the stabilizing tower reflux tank 3 along the feed pipeline 5 of the stabilizing tower reflux tank. When the water level in the stabilizing tower reflux tank 3 reaches the boundary, the water is cut off through the water bag of the stabilizing tower reflux tank 3, and the water in the water bag of the stabilizing tower reflux tank 3 is sampled and analyzed to detect the ammonium salt content in the water. When the ammonium salt content is no longer increasing Stop water injection. It should be noted that after water injection, due to water vaporization, the pressure of the stabilization tower will increase or even exceed 1.30Mpa, causing overpressure risk. Therefore, before water injection, the pressure at the top of the tower is reduced to below 1.0Mpa, so that the pressure fluctuation will not lead to overpressure after water injection. If the top pressure of the stabilization tower 2 exceeds 1.30Mpa or the top temperature exceeds 70°C, stop water injection, and further water injection is performed when the temperature and pressure are controlled within a suitable range. With the accumulation of ammonium salts in the stabilization tower reflux tank 3, some ammonium salts may enter the stabilization tower reflux pump 601 along the stabilization tower reflux tank discharge pipeline 6, causing blockage and leading to the evacuation of the stabilization tower reflux pump 601. If the stabilization tower reflux pump 601 is evacuated, stop water injection.

[0030] 2) Continuous water injection:

[0031] a. Control the top pressure of the stabilizer tower 2 to drop below 1.0 Mpa and the bottom temperature of the stabilizer tower 2 to drop below 160 °C. Inject water into the trays of the stabilizer tower 2 through the first water injection pipeline 11. Ensure the pressure stability during the water injection process. If the pressure exceeds the limit, stop the water injection. The deaerated water injected through the first water injection pipeline 11 flows into the stabilizer tower reflux drum 3 along the feed pipeline 5 of the stabilizer tower reflux drum. When the water level in the stabilizer tower reflux drum 3 reaches the interface level, drain the water through the water pocket of the stabilizer tower reflux drum 3. Take a sample of the water in the water pocket of the stabilizer tower reflux drum 3 for analysis to detect the ammonium salt content in the water. Take a sample from the stable gasoline outlet 9 of the stabilizer tower 2 once every hour for analysis to check the impurity situation in the gasoline;

[0032] b. If the top pressure of the stabilizer tower 2 exceeds 1.25 Mpa or the top temperature exceeds 70 °C, stop the water injection; if the stabilizer tower reflux pump 601 experiences air extraction, stop the water injection. When the water level in the stabilizer tower reflux drum 3 reaches the interface level, stop the water injection through the first water injection pipeline 11 and inject water into the stabilizer tower 2 through the second water injection pipeline 12. Detect the chloride ion content in the stabilizer tower reflux drum 3. When the chloride ion content no longer rises, inject water into the air cooler at the top of the stabilizer tower 2 through the third water injection pipeline 13 to clean the ammonium salt in the internal tubes of the air cooler 501 at the top of the stabilizer tower;

[0033] c. Detect the exhaust gas volume at the top of the stabilizer tower 2. When the exhaust gas volume rises above 400 Nm 3 / h, stop the water injection through the second water injection pipeline 12 and the third water injection pipeline 13, and the system operates normally for 1 h;

[0034] d. Take a sample from the gasoline outlet of the stabilizer tower 2 for detection. When the C5 content in the gasoline product is less than 5% and it is qualified, stop washing the tower. If the product is still unqualified, repeat the above step 2).

[0035] During the above water injection process, the deaerated water pressure of the first water injection pipeline 11, the second water injection pipeline 12, and the third water injection pipeline 13 is greater than 1.5 MPa.

[0036] During the water injection process, the liquefied gas, gasoline, and water in the stabilizer tower 2 are mixed on the trays. The water will be dispersed to each tray in the tower along with the gasoline and liquefied gas. In this way, the water can fully contact the ammonium salt on the trays to achieve the purpose of dissolving the ammonium salt. Part of the water will go to the tower bottom with the gasoline and be sent out of the device through the stable gasoline outlet 9 and the stable gasoline discharge pipeline 10; another part of the water will enter the stabilizer tower reflux drum 3 together with the liquefied gas. The water is cut out from the bottom water pocket of the stabilizer tower reflux drum, and the liquefied gas is sent back as reflux or out of the device.

[0037] Although the present invention has been described in detail by reference to the accompanying drawings and in conjunction with the preferred embodiments, the present invention is not limited thereto. Without departing from the spirit and essence of the present invention, those of ordinary skill in the art may make various equivalent modifications or substitutions to the embodiments of the present invention, and all such modifications or substitutions should fall within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. An online ammonium salt removal system for a stabilizing tower tray, characterized in that, It includes a re - contact tank (1), a stabilizer column (2), a stabilizer reflux drum (3) and a controller. The re - contact tank (1) and the stabilizer column (2) are connected through a stabilizer feed pipeline (4). A stabilizer feed heat exchanger (401) and a feed control valve (402) are arranged on the stabilizer feed pipeline (4). A pressure sensor and a first temperature sensor are arranged at the top of the stabilizer column (2), a second temperature sensor is arranged at the bottom of the stabilizer column (2), a liquid level sensor is arranged in the stabilizer reflux drum (3), and the feed control valve (402), the pressure sensor, the liquid level sensor, the first temperature sensor and the second temperature sensor are all electrically connected to the controller; The stabilizer column (2) and the stabilizer reflux drum (3) are connected through a stabilizer reflux drum feed pipeline (5). A stabilizer overhead air cooler (501) and a stabilizer overhead cooler (502) are arranged on the stabilizer reflux drum feed pipeline (5); The stabilizer reflux drum (3) is communicated with a stabilizer reflux feed inlet (7) through a stabilizer reflux drum discharge pipeline (6). A liquid hydrocarbon discharge pipeline (14), a stabilizer reflux pump (601) and a reflux control valve (602) are arranged on the stabilizer reflux drum discharge pipeline (6), and the reflux control valve (602) is electrically connected to the controller; The bottom of the stabilizer column (2) is also connected with a stabilizer bottom reboiler (8) and a stabilized gasoline outlet (9), and the stabilized gasoline outlet (9) is connected with a stabilized gasoline discharge pipeline (10); It also includes a first water injection pipeline (11) arranged on the stabilizer feed pipeline (4), a second water injection pipeline (12) arranged on the stabilizer reflux drum discharge pipeline (6) and a third water injection pipeline (13) arranged on the pipeline between the stabilizer column (2) and the stabilizer overhead air cooler (501).

2. The system for online removal of ammonium salts on the trays of the stabilizing tower as claimed in claim 1, wherein, The first water injection pipeline (11) is arranged on the pipeline between the re - contact tank (1) and the stabilizer feed heat exchanger (401), and the second water injection pipeline (12) is arranged before the reflux control valve (602).

3. The system for online removal of ammonium salts on the trays of the stabilizing column as claimed in claim 1, wherein Flow - limiting orifice plates are arranged on the first water injection pipeline (11), the second water injection pipeline (12) and the third water injection pipeline (13).

4. A method for online removing ammonium salts on the trays of a stabilizing tower by using the system according to claim 1, characterized in that, It is divided into two stages: intermittent water injection and continuous water injection; 1) Intermittent water injection: Water is injected into the trays of the stabilizer column (2) through the first water injection pipeline (11). The water injection is carried out in stages, with each injection lasting for one minute. Ensure the pressure is stable before water injection. The injected water flows into the stabilizer reflux drum (3) along the stabilizer reflux drum feed pipeline (5). When the water level in the stabilizer reflux drum (3) reaches the interface level, water is drained through the water pocket of the stabilizer reflux drum (3). Water samples are taken from the water pocket of the stabilizer reflux drum (3) for analysis to detect the ammonium salt content in the water. Stop water injection when the ammonium salt content no longer increases; 2) Continuous water injection: a. Water is injected into the trays of the stabilizer column (2) through the first water injection pipeline (11). Ensure the pressure is stable during the water injection process. The injected water flows into the stabilizer reflux drum (3) along the stabilizer reflux drum feed pipeline (5). When the water level in the stabilizer reflux drum (3) reaches the interface level, water is drained through the water pocket of the stabilizer reflux drum (3). Water samples are taken from the water pocket of the stabilizer reflux drum (3) for analysis to detect the ammonium salt content in the water; b. When the water level in the reflux drum (3) of the stabilizing column reaches the interface level, the first water injection pipeline (11) stops water injection, and water is injected into the stabilizing column (2) through the second water injection pipeline (12). The chloride ion content in the reflux drum (3) of the stabilizing column is detected. When the chloride ion content no longer rises, water is injected into the air cooler at the top of the stabilizing column (2) through the third water injection pipeline (13) to clean the ammonium salts in the internal tube bundle of the air cooler (501) at the top of the stabilizing column. c. Detect the exhaust gas volume at the top of the stabilizing tower (2). When the exhaust gas volume rises to more than 400 Nm 3 / h, both the second water injection pipeline (12) and the third water injection pipeline (13) stop water injection, and the system operates normally for 1 h; d. Take the bottom discharge of the stabilizing column (2) for inspection. Stop washing the column after the product is qualified. If the product is still unqualified, repeat step 2) above.

5. The method for online removal of ammonium salts on the trays of a stabilizing column according to claim 4, characterized in that, In step 1), before injecting water into the trays of the stabilizing column (2) through the first water injection pipeline (11), control the top pressure of the stabilizing column (2) to drop below 1.0 Mpa and the bottom temperature of the stabilizing column (2) to drop below 180 °C.

6. The method for online removing ammonium salts on the trays of a stabilizing column according to claim 4, characterized in that, In step 1), if the top pressure of the stabilizing column (2) exceeds 1.30 Mpa or the top temperature exceeds 70 °C, stop water injection; if the stabilizing column reflux pump (601) shows a cavitation phenomenon, stop water injection.

7. The method for online removal of ammonium salts on the trays of a stabilizing tower according to claim 4, characterized in that, In step 2), before injecting water into the trays of the stabilizing column (2) through the first water injection pipeline (11), control the top pressure of the stabilizing column (2) to drop below 1.0 Mpa and the bottom temperature of the stabilizing column (2) to drop below 160 °C.

8. The method for online removing ammonium salts on the trays of a stabilizing column according to claim 4, characterized in that, In step 2), if the top pressure of the stabilizing column (2) exceeds 1.25 Mpa or the top temperature exceeds 70 °C, stop water injection; if the stabilizing column reflux pump (601) shows a cavitation phenomenon, stop water injection.

9. The method for online removal of ammonium salts on the trays of a stabilizing column according to claim 4, characterized in that, The water pressure of the first water injection pipeline (11), the second water injection pipeline (12) and the third water injection pipeline (13) is greater than 1.5 MPa.

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