Nitrogen cyclic utilization and temperature control device

Abstract

The utility model relates to the technical field of equipment for producing hydrogen peroxide by an anthraquinone method, in particular to a nitrogen recycling and temperature control device, which is characterized in that a first inlet of a hydrogenation tower is communicated with a common pipeline of a hydrogen pipe network and a nitrogen pipe network, and an outlet of the hydrogenation tower is communicated with a regenerated steam condenser; the regenerated steam condenser is communicated with a regenerated steam condensate metering tank, the regenerated steam condensate metering tank is communicated with a nitrogen circulating fan, the nitrogen circulating fan is communicated with a nitrogen circulating heater, the nitrogen circulating heater is communicated with a nitrogen filter, and the nitrogen filter is communicated with a shared pipeline of a steam net pipe through a circulating nitrogen pipeline; the steam net pipe sharing pipeline is communicated with a second inlet in the top of the hydrogenation tower. By adopting the nitrogen recycling and temperature control device disclosed by the utility model, the nitrogen recycling can be effectively realized, and the temperature of the nitrogen entering the hydrogenation tower can be accurately controlled.

Description

Technical Field

[0001] This utility model relates to the technical field of equipment for producing hydrogen peroxide using the anthraquinone process, and in particular to a nitrogen recycling and temperature control device. Background Technology

[0002] In the industrial process of producing hydrogen peroxide using the anthraquinone process, the catalyst in the hydrogenation tower is the key reaction medium. With prolonged operation, when the hydrogenation temperature and pressure reach their specified upper limits, but the hydrogenation efficiency fails to meet the requirements for yield and product concentration, the catalyst needs to be regenerated to restore its activity. Currently, the commonly used regeneration method involves first using steam to purge the carbon deposits and impurities adhering to the catalyst surface, followed by nitrogen purging to further remove residual moisture and other impurities after steam purging, while simultaneously preventing oxidation of the catalyst upon contact with air at high temperatures.

[0003] However, existing regeneration processes have significant drawbacks. On the one hand, after purging the catalyst in the hydrogenation tower with nitrogen, it is mostly vented directly without effective recycling, greatly increasing production costs for enterprises. On the other hand, even in processes that attempt nitrogen recycling, improper temperature control before the nitrogen enters the hydrogenation tower can cause a sharp drop in the catalyst surface temperature, generating stress inside the catalyst and severely affecting its activity and lifespan. Currently, the steam regeneration process in hydrogenation towers lacks sophisticated nitrogen recycling and precise temperature preheating control technologies, making it difficult to meet the needs of industrial production in terms of energy saving and ensuring catalyst activity. Utility Model Content

[0004] The purpose of this invention is to provide a nitrogen recycling and temperature control device, which can effectively realize the recycling of nitrogen and accurately control the temperature of nitrogen entering the hydrogenation tower, thus solving the problems of low nitrogen recycling rate and difficulty in accurately controlling the nitrogen temperature before entering the hydrogenation tower during catalyst regeneration.

[0005] To achieve the above objectives, this utility model provides a nitrogen recycling and temperature control device, including a hydrogenation tower, a regenerated steam condenser, a regenerated steam condensate metering tank, a nitrogen circulation fan, a nitrogen circulation heater, and a nitrogen filter. The first inlet at the top of the hydrogenation tower is connected to a shared pipeline of the hydrogen and nitrogen pipelines. The outlet at the bottom of the hydrogenation tower is connected to the regenerated steam condenser. The regenerated steam condenser is connected to the regenerated steam condensate metering tank. The nitrogen outlet of the regenerated steam condensate metering tank is connected to the nitrogen circulation fan. The nitrogen circulation fan is connected to the nitrogen circulation heater. The nitrogen circulation heater is connected to the nitrogen filter. The nitrogen filter is connected to the steam network pipeline via a circulating nitrogen pipeline. The shared pipeline of the steam network pipeline is connected to the second inlet at the top of the hydrogenation tower.

[0006] Preferably, a first flow meter and a first regulating valve are connected to a shared pipeline for the hydrogen and nitrogen pipelines. A first pressure transmitter is installed at the top of the hydrogenation tower. The first pressure transmitter is interlocked with the first regulating valve. A secondary pipeline is provided as a bypass of the main pipeline of the first regulating valve. A first shut-off valve is installed on the secondary pipeline. A first butterfly valve is installed on the pipeline between the outlet at the bottom of the hydrogenation tower and the regenerated steam condenser.

[0007] Preferably, one side of the regenerated steam condenser is connected to a circulating water inlet and a circulating water outlet, and a second butterfly valve is installed on both the circulating water inlet and the circulating water outlet pipes. A second shut-off valve is installed on the pipe between the bottom outlet of the regenerated steam condenser and the regenerated steam condensate metering tank.

[0008] Preferably, the bottom of the regenerated steam condensate metering tank is connected to the drain pipe, a second regulating valve is provided on the drain pipe, and a remote level gauge is provided on the bypass of the regenerated steam condensate metering tank, and the remote level gauge is interlocked with the second regulating valve.

[0009] Preferably, the regenerated steam condensate metering tank is also connected to the exhaust gas recovery device through an exhaust gas emission pipe, and a third shut-off valve is provided on the exhaust gas emission pipe.

[0010] Preferably, the top of the regenerated steam condensate metering tank is equipped with a wire mesh demister.

[0011] Preferably, a third regulating valve is provided on the inlet pipe of the nitrogen circulating fan, and a second pressure transmitter is provided on the outlet pipe of the nitrogen circulating fan. The second pressure transmitter is interlocked with the third regulating valve. A bypass pipe second is provided for the nitrogen circulating fan, and a fourth shut-off valve is provided on the bypass pipe second.

[0012] Preferably, a temperature sensor is installed on the outlet pipe connecting the nitrogen circulation heater and the nitrogen filter. One side of the nitrogen circulation heater is connected to the steam inlet pipe and the steam outlet pipe. A fourth regulating valve is installed on the steam inlet pipe. The temperature sensor is interlocked with the fourth regulating valve. A bypass pipe three is provided for the steam inlet pipe. A fifth shut-off valve is installed on both the steam outlet pipe and the bypass pipe three.

[0013] Preferably, a second flow meter and a fifth regulating valve are provided on the circulating nitrogen pipeline connected to the nitrogen filter. The second flow meter and the fifth regulating valve are interlocked. A bypass pipeline four is provided on the circulating nitrogen pipeline, and a sixth shut-off valve is provided on the bypass pipeline four.

[0014] The beneficial effects of this utility model are:

[0015] (1) The present invention adopts a nitrogen recycling and temperature control device with the above structure, which realizes the recycling of nitrogen. After the nitrogen blown out of the hydrogenation tower is condensed by the regenerated steam condenser and separated by the regenerated steam condensate metering tank, the circulating nitrogen is compressed and pressurized by the nitrogen circulation fan, preheated by the nitrogen circulation heater, and filtered by the nitrogen filter before re-entering the hydrogenation tower. This reduces the cost of nitrogen procurement and preparation, and ensures a stable supply of nitrogen, avoiding economic losses caused by production interruption.

[0016] (2) The present invention adopts a nitrogen recycling and temperature control device with the above structure. The nitrogen is preheated by the nitrogen circulation heater so that it reaches a suitable temperature before entering the hydrogenation tower, which effectively reduces the moisture content in the circulating nitrogen, accelerates the removal of moisture and impurities on the catalyst surface, shortens the catalyst heating time, and thus significantly shortens the regeneration time and improves production efficiency.

[0017] (3) The present invention adopts a nitrogen recycling and temperature control device with the above structure. The regenerated steam condenser and the regenerated steam condensate metering tank are common equipment for steam condensation recovery and nitrogen recycling, which simplifies the regeneration process, reduces the number of equipment investments, and lowers the equipment maintenance cost.

[0018] The technical solution of this utility model will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a nitrogen recycling and temperature control device according to the present invention.

[0020] Figure 2 This is a schematic diagram of the structure of a nitrogen recycling and temperature control device according to this utility model. Figure 2 In this context, HL represents the hydrogen pipeline network, NL represents the nitrogen pipeline network, and ST represents the steam pipeline network.

[0021] Figure label:

[0022] 1. Hydrogenation tower; 2. Regenerated steam condenser; 3. Regenerated steam condensate metering tank; 4. Nitrogen circulating fan; 5. Nitrogen circulating heater; 6. Nitrogen filter; 7. First flow meter; 8. First regulating valve; 9. First pressure transmitter; 10. Secondary pipeline; 11. First shut-off valve; 12. First butterfly valve; 13. Circulating water inlet; 14. Circulating water outlet; 15. Second butterfly valve; 16. Second shut-off valve; 17. Sewage pipe; 18. Second regulating valve ; 19. Remote level gauge; 20. Exhaust gas discharge pipe; 21. Third shut-off valve; 22. Third regulating valve; 23. Second pressure transmitter; 24. Secondary pipeline; 25. Fourth shut-off valve; 26. Steam inlet pipe; 27. Steam outlet pipe; 28. Temperature sensor; 29. ​​Fourth regulating valve; 30. Third secondary pipeline; 31. Fifth shut-off valve; 32. Secondary flow meter; 33. Fifth regulating valve; 34. Fourth secondary pipeline; 35. Sixth shut-off valve. Detailed Implementation

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments. Unless otherwise defined, the technical or scientific terms used in this invention should have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The features mentioned above or in the specific examples mentioned in this invention can be combined arbitrarily, and these specific embodiments are only used to illustrate this invention and are not intended to limit the scope of this invention.

[0024] Example

[0025] like Figures 1 to 2 As shown, this utility model provides a nitrogen recycling and temperature control device, including a hydrogenation tower 1, a regenerated steam condenser 2, a regenerated steam condensate metering tank 3, a nitrogen circulation fan 4, a nitrogen circulation heater 5, and a nitrogen filter 6. Two hydrogenation towers 1 are arranged parallel to each other, and the working principle and connecting pipes of the two hydrogenation towers 1 are the same. The first inlet at the top of the hydrogenation tower 1 is connected to a shared pipe with the hydrogen and nitrogen pipelines, used to introduce hydrogen and nitrogen into the hydrogenation tower 1. The supplied nitrogen is mainly used for cooling during the regeneration of the hydrogenation catalyst.

[0026] A first flow meter 7 and a first regulating valve 8 are connected to a shared pipeline for the hydrogen and nitrogen pipelines. A first pressure transmitter 9 is installed at the top of the hydrogenation tower 1. The first flow meter 7 is used to measure the flow rate of nitrogen entering the hydrogenation tower 1, the first regulating valve 8 is used to regulate the internal pressure of the hydrogenation tower 1, and the first pressure transmitter 9 is used to monitor changes in the internal pressure of the hydrogenation tower 1. The first pressure transmitter 9 is interlocked with the first regulating valve 8. When the internal pressure of the hydrogenation tower 1 changes, the first regulating valve 8 will automatically adjust its opening according to the change in the value of the first pressure transmitter 9 to control the amount of nitrogen input to the hydrogenation tower 1, thereby ensuring the stability of the internal pressure of the hydrogenation tower 1 and preventing abnormal pressure from affecting the reaction.

[0027] A bypass line 10 is provided on the main pipeline of the first regulating valve 8. A first shut-off valve 11 is installed on the bypass line 10. When the main pipeline malfunctions or requires maintenance, the first regulating valve 8 can be closed and the first shut-off valve 11 opened, allowing gas to enter the hydrogenation tower 1 through the bypass line 10, ensuring continuous production. A first butterfly valve 12 is installed on the pipeline between the outlet at the bottom of the hydrogenation tower 1 and the regenerated steam condenser 2. By adjusting the opening of the first butterfly valve 12, the flow rate and velocity of the gas entering the regenerated steam condenser 2 from the hydrogenation tower 1 can be controlled.

[0028] The outlet at the bottom of the hydrogenation tower 1 is connected to the regenerated steam condenser 2, allowing the gas containing impurities and moisture discharged from the hydrogenation tower 1 to enter the regenerated steam condenser 2 for treatment, which is used to condense and cool the circulating nitrogen output from the hydrogenation tower 1. A circulating water inlet 13 and a circulating water outlet 14 are connected to one side of the regenerated steam condenser 2. Both the circulating water inlet 13 and the circulating water outlet 14 are equipped with second butterfly valves 15. By adjusting the opening of the second butterfly valves 15, the flow rate of the circulating water can be precisely controlled, thereby controlling the temperature inside the regenerated steam condenser 2 and achieving control over the cooling of the nitrogen.

[0029] The regenerated steam condenser 2 adopts a shell-and-tube heat exchanger, using circulating water with a low inlet and high outlet as the cooling medium. The circulating water flows upward along the tube side from the bottom side of the regenerated steam condenser 2 and exchanges heat with nitrogen through the tube wall. The nitrogen blown out from the hydrogenation tower 1 enters from the top end cap of the regenerated steam condenser 2, flows downward along the shell side, is guided by baffles, and exchanges heat with the low-temperature circulating water through the tube wall. This causes the condensable components (water vapor, aromatics) entrained in the nitrogen to release their latent heat and condense into liquid. The condensate flows downward naturally under the action of gravity, collects at the bottom of the shell side, and converges from the bottom end cap to the outlet of the regenerated steam condenser.

[0030] The regenerated steam condenser 2 is connected to the regenerated steam condensate metering tank 3, allowing the condensate formed during condensation to flow into the regenerated steam condensate metering tank 3 for collection and further nitrogen separation. A second shut-off valve 16 is installed on the pipeline between the bottom outlet of the regenerated steam condenser 2 and the regenerated steam condensate metering tank 3. The second shut-off valve 16 is used to control the speed and flow rate of the condensate flowing from the regenerated steam condenser 2 into the regenerated steam condensate metering tank 3, ensuring that the condensate can enter the regenerated steam condensate metering tank 3 stably and orderly.

[0031] The top of the regenerated steam condensate metering tank 3 is equipped with a wire mesh demister (the wire mesh demister is existing technology and is not shown in the attached diagram). Because the nitrogen gas entering the regenerated steam condensate has a low density, it rises to the top of the regenerated steam condensate metering tank 3. The condensate entrained in the nitrogen gas is filtered by the wire mesh demister, and because the condensate has a high density, it settles and collects at the bottom of the regenerated steam condensate metering tank 3 under the action of gravity.

[0032] The bottom of the regenerated steam condensate metering tank 3 is connected to the drain pipe 17, which is equipped with a second regulating valve 18. A remote level gauge 19 is installed on the bypass of the regenerated steam condensate metering tank 3, and the remote level gauge 19 is interlocked with the second regulating valve 18. The remote level gauge 19 monitors the liquid level in the regenerated steam condensate metering tank 3 in real time. When the liquid level reaches a certain height, the remote level gauge 19 transmits a signal to the second regulating valve 18, which automatically opens to a certain degree to discharge excess condensate through the drain pipe 17, thereby maintaining a constant liquid level in the regenerated steam condensate metering tank 3.

[0033] The regenerated steam condensate metering tank 3 is also connected to the exhaust gas recovery device through the exhaust gas emission pipe 20. The exhaust gas emission pipe 20 is equipped with a third shut-off valve 21, which is used to control the flow rate and timing of exhaust gas emission. Excess exhaust gas is discharged to the exhaust gas recovery device for treatment, which can both prevent exhaust gas from polluting the environment and recover the useful components in it.

[0034] The nitrogen outlet of the regenerated steam condensate metering tank 3 is connected to the nitrogen circulation fan 4, which in turn is connected to the nitrogen circulation heater 5. The nitrogen circulation fan 4 is used to compress the circulating nitrogen, and the nitrogen circulation heater 5 is used to control the temperature of the circulating nitrogen. Nitrogen enters the nitrogen circulation fan 4 from the top of the regenerated steam condensate metering tank 3 along the pipeline, enters the impeller center axially, and is thrown towards the outer edge of the impeller by centrifugal force, converting kinetic energy into pressure energy, increasing the nitrogen pressure by 0.1~0.2MPa. After being collected by the volute, the high-pressure nitrogen is sent from the outlet to the inlet of the nitrogen circulation heater 5.

[0035] A third regulating valve 22 is installed on the inlet pipe of the nitrogen circulating fan 4, and a second pressure transmitter 23 is installed on the outlet pipe of the nitrogen circulating fan 4. The second pressure transmitter 23 is interlocked with the third regulating valve 22. The second pressure transmitter 23 monitors the pressure of nitrogen at the outlet of the nitrogen circulating fan 4 in real time. When the pressure changes, it transmits a signal to the third regulating valve 22. The third regulating valve 22 automatically adjusts its opening according to the pressure change to ensure that the fan can stably deliver nitrogen and maintain a suitable pressure and flow rate throughout the circulation system. A bypass pipe 24 is provided for the nitrogen circulating fan 4, and a fourth shut-off valve 25 is installed on the bypass pipe 24. When the nitrogen circulating fan 4 needs to be inspected, maintained, or its flow rate adjusted, the main fan pipe can be closed and the fourth shut-off valve 25 can be opened to allow nitrogen to continue circulating through the bypass pipe 24, ensuring the normal operation of the system.

[0036] The nitrogen circulation heater 5 adopts a shell-and-tube heat exchanger. One side of the nitrogen circulation heater 5 is connected to the steam inlet pipe 26 and the steam outlet pipe 27. The heat source of the shell-and-tube heat exchanger comes from steam. The steam flows down from the upper side wall of the nitrogen circulation heater 5 along the tube side and exchanges heat with the low temperature nitrogen through the tube wall. The steam condenses into liquid water, releases a large amount of heat, and is discharged from the lower part of the tube side. The nitrogen enters from the bottom end cap of the shell-and-tube heat exchanger along the shell side, and is repeatedly laterally swept by the baffles to fully absorb the heat transferred by the tube wall. Finally, it is discharged from the upper end cap.

[0037] The nitrogen circulation heater 5 is connected to the nitrogen filter 6, and the heated nitrogen gas passes through the nitrogen filter 6 to remove impurities. A temperature sensor 28 is installed on the outlet pipe connecting the nitrogen circulation heater 5 and the nitrogen filter 6, and a fourth regulating valve 29 is installed on the steam inlet pipe 26. The temperature sensor 28 and the fourth regulating valve 29 are interlocked. By adjusting the opening of the fourth regulating valve 29, the steam flow rate of the shell-and-tube heat exchanger is adjusted, controlling the nitrogen temperature at 40~50℃. The temperature sensor 28 monitors the nitrogen temperature in real time and feeds the temperature signal back to the DCS control system. When the temperature deviates from the set range, the DCS control system automatically adjusts the opening of the fourth regulating valve 29 to ensure that the nitrogen temperature entering the hydrogenation tower 1 is stable at 40~50℃, preventing the catalyst activity from being affected by excessively low nitrogen temperature. A bypass line 30 is provided on the steam inlet pipe 26. Both the steam outlet pipe 27 and the bypass line 30 are equipped with a fifth shut-off valve 31. When the steam inlet pipe 26 or the fourth regulating valve 29 needs to be inspected, maintained or specially regulated, the main pipe can be closed and the bypass line 30 and the corresponding fifth shut-off valve 31 can be opened to transport and regulate steam through the bypass line.

[0038] The nitrogen filter 6 is connected to the steam network pipe via a circulating nitrogen pipeline. The steam network pipe is connected to the second inlet at the top of the hydrogenation tower 1. Circulating nitrogen enters the second inlet at the top of the hydrogenation tower 1 through the circulating nitrogen pipeline and the steam network pipe, thus completing the recycling of nitrogen.

[0039] The circulating nitrogen pipeline connected to the nitrogen filter 6 is equipped with a second flow meter 32 and a fifth regulating valve 33. The second flow meter 32 and the fifth regulating valve 33 are interlocked. The second flow meter 32 is used to measure the flow rate of the circulating nitrogen. When the flow rate changes, the fifth regulating valve 33 automatically adjusts its opening according to the flow signal, and finally controls the nitrogen flow rate at 80~200m3 / h to ensure a stable flow rate of circulating nitrogen entering the hydrogenation tower 1, and to provide a stable gas supply for the reaction in the hydrogenation tower 1.

[0040] The circulating nitrogen pipeline has a bypass line 4 (34), which is equipped with a sixth shut-off valve 35. When the circulating nitrogen pipeline or the fifth regulating valve 33 needs to be inspected, maintained, or the flow rate needs to be adjusted, the main pipeline can be closed and the sixth shut-off valve 35 can be opened to allow nitrogen to continue circulating through the bypass line 4 (34) to maintain the normal operation of the system.

[0041] The specific working principle of this utility model is as follows:

[0042] First, hydrogen or nitrogen enters the hydrogenation tower 1 through a shared pipeline connecting the hydrogen and nitrogen pipelines. A first flow meter 7 measures the gas flow rate in real time, and a first pressure transmitter 9 monitors the pressure inside the hydrogenation tower 1. When the pressure changes, a first regulating valve 8 automatically adjusts its opening based on the pressure signal to ensure the pressure inside the hydrogenation tower 1 remains stable within a set range. The reacted gas inside the hydrogenation tower 1 enters the regenerated steam condenser 2 from the bottom outlet via a first butterfly valve 12. By adjusting the circulating water inlet 13 and the second butterfly valve 15 on the outlet pipeline, the circulating water flow rate is controlled, causing the condensable components in the gas to condense into liquid within the regenerated steam condenser 2. The condensate flows into the regenerated steam condensate metering tank 3 through the bottom outlet via a second shut-off valve 16.

[0043] The gas and liquid entering the regenerated steam condensate metering tank 3 are separated by a wire mesh demister, with the liquid in the gas being trapped. A remote level gauge 19 monitors the liquid level in the tank in real time. When the liquid level rises, the second regulating valve 18 automatically opens to a certain degree, discharging excess liquid through the drain pipe 17. Excess tail gas is discharged to the tail gas recovery device through the tail gas discharge pipe 20 and the third shut-off valve 21. The separated nitrogen enters the nitrogen circulation fan 4 from the nitrogen outlet of the regenerated steam condensate metering tank 3. The second pressure transmitter 23 monitors the outlet pressure of the nitrogen circulation fan 4, and the third regulating valve 22 adjusts the inlet flow rate of the nitrogen circulation fan 4 according to the pressure changes to ensure stable nitrogen delivery.

[0044] After nitrogen enters the nitrogen circulation heater 5, the temperature sensor 28 monitors the temperature of the heated nitrogen in real time. When the temperature is lower than the set value, the fourth regulating valve 29 automatically increases its opening to increase the steam flow and raise the nitrogen temperature; when the temperature is higher than the set value, the fourth regulating valve 29 automatically decreases its opening to reduce the steam flow. The heated nitrogen passes through the nitrogen filter 6 to filter impurities, the second flow meter 32 measures the circulating nitrogen flow, and the fifth regulating valve 33 adjusts its opening according to the flow rate to ensure a stable circulating nitrogen flow into the hydrogenation tower 1. Finally, the circulating nitrogen enters the second inlet at the top of the hydrogenation tower 1 through a shared pipeline between the circulating nitrogen pipeline and the steam network pipeline, completing the recycling of nitrogen.

[0045] In this embodiment, all regulating valves are pneumatic regulating valves. Interlocking the pneumatic regulating valves with the pressure transmitter enables automatic control of gas flow, thereby maintaining stable system pressure. All flow meters used are vortex flow meters, allowing for centralized display on both the local and remote controllers, and also include a cumulative flow function.

[0046] Therefore, the nitrogen recycling and temperature control device of this utility model with the above-mentioned structure realizes efficient recycling of nitrogen and precise temperature control, which has significant economic benefits and practical value, and can meet the needs of catalyst regeneration in hydrogenation towers in chemical production.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and not to limit it. Although the utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solution of this utility model, and these modifications or equivalent substitutions cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of this utility model.

Claims

1. A nitrogen recycling and temperature control device, characterized by: It includes a hydrogenation tower, a regenerated steam condenser, a regenerated steam condensate metering tank, a nitrogen circulating fan, a nitrogen circulating heater, and a nitrogen filter. The first inlet at the top of the hydrogenation tower is connected to a shared pipeline between the hydrogen and nitrogen pipelines. The outlet at the bottom of the hydrogenation tower is connected to the regenerated steam condenser. The regenerated steam condenser is connected to the regenerated steam condensate metering tank. The nitrogen outlet of the regenerated steam condensate metering tank is connected to the nitrogen circulating fan. The nitrogen circulating fan is connected to the nitrogen circulating heater. The nitrogen circulating heater is connected to the nitrogen filter. The nitrogen filter is connected to the steam network pipeline via a circulating nitrogen pipeline. The shared pipeline between the steam network pipeline and the second inlet at the top of the hydrogenation tower is connected to the second inlet.

2. The nitrogen recycling and temperature control device of claim 1, wherein: The hydrogen and nitrogen pipelines share a common pipeline connected to a first flow meter and a first regulating valve. A first pressure transmitter is installed at the top of the hydrogenation tower. The first pressure transmitter is interlocked with the first regulating valve. A secondary pipeline is provided as a bypass of the main pipeline of the first regulating valve. A first shut-off valve is installed on the secondary pipeline. A first butterfly valve is installed on the pipeline between the outlet at the bottom of the hydrogenation tower and the regenerated steam condenser.

3. The nitrogen recycling and temperature control device of claim 1, wherein: One side of the regenerated steam condenser is connected to a circulating water inlet and a circulating water outlet. A second butterfly valve is installed on both the circulating water inlet and the circulating water outlet pipes. A second shut-off valve is installed on the pipe between the bottom outlet of the regenerated steam condenser and the regenerated steam condensate metering tank.

4. The nitrogen recycling and temperature control device of claim 1, wherein: The bottom of the regenerated steam condensate metering tank is connected to the drain pipe, and a second regulating valve is installed on the drain pipe. A remote level gauge is installed on the bypass of the regenerated steam condensate metering tank, and the remote level gauge is interlocked with the second regulating valve.

5. The nitrogen recycling and temperature control device of claim 1, wherein: The regenerated steam condensate metering tank is also connected to the exhaust gas recovery device through an exhaust gas emission pipe, which is equipped with a third shut-off valve.

6. The nitrogen recycling and temperature control device of claim 1, wherein: A wire mesh demister is installed on the top of the regenerated steam condensate metering tank.

7. The nitrogen recycling and temperature control device of claim 1, wherein: A third regulating valve is installed on the inlet pipe of the nitrogen circulating fan, and a second pressure transmitter is installed on the outlet pipe of the nitrogen circulating fan. The second pressure transmitter is interlocked with the third regulating valve. A second bypass pipe is provided for the nitrogen circulating fan, and a fourth shut-off valve is installed on the second bypass pipe.

8. The nitrogen recycling and temperature control device of claim 1, wherein: A temperature sensor is installed on the outlet pipe connecting the nitrogen circulation heater and the nitrogen filter. One side of the nitrogen circulation heater is connected to the steam inlet pipe and the steam outlet pipe. A fourth regulating valve is installed on the steam inlet pipe. The temperature sensor is interlocked with the fourth regulating valve. A bypass pipe three is provided for the steam inlet pipe. A fifth shut-off valve is installed on both the steam outlet pipe and the bypass pipe three.

9. The nitrogen recycling and temperature control device of claim 1, wherein: The circulating nitrogen pipeline connected to the nitrogen filter is equipped with a second flow meter and a fifth regulating valve. The second flow meter and the fifth regulating valve are interlocked. The bypass of the circulating nitrogen pipeline is provided with a fourth branch pipeline, and a sixth shut-off valve is provided on the fourth branch pipeline.

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