CN223819290U - Ship liquid ammonia supply and removal system with zero ammonia residue - Google Patents

Abstract

A ship liquid ammonia supply and removal system with zero ammonia residue uses high-pressure nitrogen of 30barg to purge the liquid ammonia supply system and the inside of a host machine to remove most of ammonia fuel. The method comprises the steps of further absorbing residual ammonia by using fresh water, blowing off the fresh water after absorbing ammonia cleanly by using 30barg of high-pressure nitrogen again, and finally, forcibly evaporating and blowing the liquid ammonia supply system and the inside of a host by using 5barg of heating low-pressure nitrogen to finally achieve the effect of zero ammonia residual. After the ammonia supply system and the host machine are used for cleaning the inside of the liquid ammonia supply system, zero residue of ammonia can be realized, the cleaning effect is good, the safety of related systems and personnel on a ship can be ensured, after the operation of an ammonia fuel mode of the host machine is finished, the whole ammonia cleaning process is automatically executed, the automatic treatment of ammonia can be realized, the operation automation degree of personnel is not required, and the operation is reliable.

Description

Ship liquid ammonia supply and removal system with zero ammonia residue

Technical Field

The invention belongs to the technical field of ship liquid ammonia fuel supply, and particularly relates to a ship liquid ammonia supply and removal system with zero ammonia residues.

Background

The demand of the shipping industry for green environment-friendly ships is continuously increased, the development and application of innovative technology developed in the shipping industry, the introduction of alternative fuels and other emission reduction measures become unprecedented, and the use of low-carbon even zero-carbon fuels to replace traditional marine fuels is an important measure for emission reduction in the shipping industry. Among the many new fuels, ammonia is one of the potential zero carbon fuels, can be stored on board at a temperature of 33 ℃ below zero, has acceptable energy density, does not generate carbide and sulfide when burned, is convenient to store and transport, has sufficient capacity, has low price and the like, and is the focus of research in the industry.

Similar to the LNG supply system, the liquid ammonia fuel supply system must be purged with nitrogen after use or before maintenance is required to ensure that no ammonia fuel remains, so as to avoid danger. Because LNG is in a gaseous state in a gas supply system, the LNG is easy to blow off, but in the liquid ammonia in the gas supply system, ammonia is easy to gather and remain at welding joints, bent pipe positions, concave positions of various equipment and pipe accessories, blind ends of pipelines and the like in the gas supply system, the LNG is difficult to completely blow off, and whether the LNG is blown off is difficult to judge. Unlike natural gas, ammonia is toxic and if not completely removed, it can cause the following problems:

Firstly, because ammonia has strong corrosiveness, the residual ammonia can corrode equipment and pipelines for a long time, so that the system is in fault and even in leakage risk.

Secondly, if the liquid ammonia fuel which is not blown clean remains in the supply system or the host, the liquid ammonia slowly absorbs heat to evaporate with the lapse of time, so that the pressure in the system increases, and the risk of overpressure of the system may occur.

Thirdly, if the supply system or the host is overhauled, the residual liquid ammonia which is insufficiently purged can be quickly evaporated and spread after contacting the atmosphere, and the toxicity of the liquid ammonia can cause serious threat to the personal safety of operation overhaulers, and even has the risk of explosion.

Disclosure of Invention

In order to solve the problems, the invention provides a ship liquid ammonia supply and removal system with zero ammonia residue, which aims to achieve the purpose of thoroughly purging ammonia in a host machine, and adopts the following technical scheme:

A ship liquid ammonia supply and removal system free of ammonia residues is characterized in that compressed and dried air is provided for a nitrogen generator through an air compressor and an air dryer before the liquid ammonia supply system is operated, and produced nitrogen is stored in a nitrogen low-pressure tank.

The nitrogen pressurizer stores the nitrogen after further pressurization in a nitrogen high-pressure tank, the fresh water buffer tank is filled with fresh water through a fresh water system on the ship, the water quantity of 80% of liquid level is kept, the nitrogen low-pressure tank, the nitrogen high-pressure tank and the fresh water buffer tank are respectively filled with nitrogen and fresh water, and the whole ammonia removal system is ready.

The ship can start voyage only under the condition that an ammonia removal system is ready, after the load of the host reaches 25%, the operation of the host is switched from a diesel mode to an ammonia fuel mode, when the ship is about to arrive, the diesel mode is switched back, after the diesel mode is switched back, the liquid ammonia supply system and the residual liquid ammonia in the host are subjected to first purging operation through high-pressure nitrogen, fresh water is utilized to absorb nitrogen after the first purging operation, the high-pressure nitrogen is utilized to carry out second purging operation after the fresh water absorbs ammonia, and low-pressure nitrogen is utilized to heat after the second purging operation to carry out third purging operation.

The ship liquid ammonia supply and removal system with zero ammonia residue is characterized in that the air compressor is sequentially connected with the air dryer, the nitrogen generator and the nitrogen low-pressure tank through pipelines, the nitrogen low-pressure tank is sequentially connected with the electric heater and the host through one pipeline and is sequentially connected with the nitrogen booster, the nitrogen high-pressure tank and the host through the other pipeline, a fifth remote control valve is arranged on a passage of the electric heater to the host, and a first remote control valve is arranged on a passage of the nitrogen high-pressure tank to the host.

The main machine is respectively connected with the ammonia treatment unit and the ammonia water collecting cabinet through pipelines, the ammonia treatment unit is connected with the ventilation mast, a second remote control valve and an ammonia concentration transmitter are arranged on a passage of the main machine, which is communicated with the ammonia treatment unit, and a pressure transmitter and a fourth remote control valve are arranged on a passage of the main machine, which is communicated with the ammonia water collecting cabinet.

The host is connected with a fresh water buffer tank, and a fresh water transfer pump and a third remote control valve are arranged on a passage of the fresh water buffer tank, which leads to the host.

The ship liquid ammonia supply and removal system with zero ammonia residue further comprises a nitrogen low-pressure tank with a storage pressure of 10barg.

The ship liquid ammonia supply and removal system with zero ammonia residue further comprises a nitrogen high-pressure tank with a storage pressure of 30barg.

According to the ship liquid ammonia supply and removal system with zero ammonia residue, the pressure regulating valve is arranged at the inlet of the electric heater.

The above-mentioned zero ammonia residual ship liquid ammonia supplies and clears away system, and further, well accuse system is controlled first remote control valve, second remote control valve, third remote control valve, fourth remote control valve, fifth remote control valve.

According to the ship liquid ammonia supply and removal system with zero ammonia residue, when the high-pressure nitrogen is used for purging, the ammonia concentration transmitter is used for monitoring that the ammonia concentration in the pipeline is reduced to 300ppm, and the first remote control valve and the second remote control valve are closed.

According to the ship liquid ammonia supply and removal system with zero ammonia residue, when the low-pressure nitrogen is used for heating and purging, and the ammonia concentration in the ammonia concentration transmitter monitoring pipeline is reduced to below 1ppm, the fifth remote control valve and the second remote control valve are closed.

In the above-mentioned zero ammonia residue ship liquid ammonia supply and removal system, further, when the low-pressure nitrogen is used for heating and purging, the pressure regulating valve regulates the low-pressure nitrogen to 5barg, and then the low-pressure nitrogen is sent to the electric heater to be heated to 70 DEG C

The beneficial effects of the invention are as follows:

1. after the invention is used for cleaning the liquid ammonia supply system and the inside of the host, zero residue of ammonia can be realized, and the ammonia cleaning effect is good.

2. The invention can ensure the safety of related systems and personnel on the ship.

3. After the operation of the main engine ammonia fuel mode is finished, the whole ammonia removal process is automatically executed, the automatic treatment of ammonia can be realized, the operation automation degree of personnel is not required, and the operation is reliable.

Drawings

FIG. 1 is a schematic diagram of a system of the present invention;

The device comprises a 1-air compressor, a 2-air dryer, a 3-nitrogen generator, a 4-nitrogen low-pressure tank, a 5-nitrogen booster, a 6-nitrogen high-pressure tank, a 7-fresh water buffer tank, an 8-host, a 9-first remote control valve, a 10-second remote control valve, an 11-ammonia concentration transmitter, a 12-ammonia processing unit, a 13-ventilation mast, a 14-third remote control valve, a 15-fresh water transfer pump, a 16-pressure transmitter, a 17-fourth remote control valve, an 18-ammonia water collection cabinet, a 19-fifth remote control valve, a 20-pressure regulating valve and a 21-electric heater.

Detailed Description

The invention will be further described with reference to the accompanying drawings.

The utility model provides a zero ammonia residual's boats and ships liquid ammonia supply scavenging system, as shown in figure 1, before liquid ammonia supply system supplies and host computer operation, has passed through air compressor 1, air dryer 2, and the air after compression, drying provides membrane nitrogen generator 3, and the nitrogen gas of output is stored in nitrogen gas low pressure tank 4, and storage pressure is 10barg. The further pressurized nitrogen was then stored in a nitrogen autoclave 6 at a storage pressure of 30barg by means of a nitrogen booster 5. The fresh water buffer tank 7 is filled with fresh water through a fresh water system on the ship and maintains a certain level of water. In summary, before the liquid ammonia supply system and the host machine are operated, the nitrogen low-pressure tank, the nitrogen high-pressure tank and the fresh water buffer tank are respectively filled with nitrogen and fresh water, and the whole ammonia removal system is ready.

The ship can only start to navigate under the condition that the ammonia removal system is ready, and the engine is switched to operate in the ammonia fuel mode from diesel after the load of the engine reaches 25%. After the ship is switched back to the diesel mode when coming to port, the liquid ammonia is remained in the liquid ammonia supply system and the host computer 8, and the ammonia removal system of the invention always in standby starts to work at the moment, and the specific flow can be divided into the following four operation steps:

Step one, high-pressure nitrogen purging operation. The first remote control valve 9 and the second remote control valve 10 are opened, the high-pressure nitrogen of 30barg is used for purging the inside of the liquid ammonia supply system and the host computer 8, the central control system can monitor the concentration of the purged ammonia through the ammonia concentration transmitter 11 in real time in the purging process, and when the concentration is reduced to about 300ppm, the first remote control valve 9 and the second remote control valve 10 can be closed, and the high-pressure nitrogen purging operation is stopped. The mixture containing liquid ammonia, ammonia and nitrogen after purging enters an ammonia treatment unit 12, the liquid ammonia is recycled as fuel, the ammonia is absorbed and treated, and the residual nitrogen is discharged into the atmosphere through a ventilation mast 13.

And step two, fresh water absorption operation. After the high-pressure nitrogen purging operation is completed, the third remote control valve 14 is opened, fresh water in the fresh water buffer tank 7 is transported to the liquid ammonia supply system and the inside of the host machine by the fresh water transfer pump 15, and ammonia remaining in the fresh water after the high-pressure nitrogen purging operation is absorbed by fresh water by utilizing the characteristic that ammonia is easily dissolved in water. Along with the slow injection of fresh water into the liquid ammonia supply system and the inside of the host, the pressure value detected by the pressure transmitter 16 will rise along with the slow injection of fresh water, when the set value is reached, the fresh water is known to be full, at the moment, the third remote control valve 14 and the fresh water transfer pump 15 are automatically closed by the central control system, then the central control system automatically takes water from the fresh water system on the ship, and the fresh water buffer tank 7 is filled to about 80% of the liquid level to wait for the next use.

And step three, purging the secondary operation by high-pressure nitrogen. After the fresh water absorption operation is finished, the first remote control valve 9 and the fourth remote control valve 17 are opened, the fresh water is purged into the ammonia water collection cabinet 18 by high-pressure nitrogen, and the rest nitrogen containing a small amount of ammonia gas is discharged through the ventilation mast after passing through the ammonia treatment unit 12. After the operation is finished, the first remote control valve 9 and the fourth remote control valve 17 are closed.

And fourthly, heating and blowing the nitrogen under low pressure. After the secondary operation of the high-pressure nitrogen purging is finished, the interior of the liquid ammonia supply system and the host machine is basically cleaned, a fifth remote control valve 19 and a second remote control valve 10 are opened, the low-pressure nitrogen is regulated to 5barg through a pressure regulating valve 20, the low-pressure nitrogen is heated to about 70 ℃ through an electric heater 21 and then is introduced into the interior of the liquid ammonia supply system and the host machine, and a small amount of residual fresh water and ammonia are forced to evaporate and are discharged through an ammonia treatment unit and an air permeable mast. In the process, the ammonia concentration is monitored in real time through the ammonia concentration transmitter 11, and when the ammonia concentration is reduced to below 1ppm, the fifth remote control valve 19 and the second remote control valve 10 are closed, so that the whole ammonia removal operation is completed. At this time, the liquid ammonia supply system and the inside of the host are completely dried and filled with nitrogen, ammonia is completely removed, and potential safety hazards caused by ammonia residues cannot be caused in the follow-up process.

Claims (8)

1. A ship liquid ammonia supply and removal system free of ammonia residues is characterized in that an air compressor (1) is sequentially connected with an air dryer (2), a nitrogen generator (3) and a nitrogen low-pressure tank (4) through pipelines, the nitrogen low-pressure tank is sequentially connected with an electric heater (21) and a host machine (8) through one pipeline, and is sequentially connected with a nitrogen booster (5), a nitrogen high-pressure tank (6) and the host machine through the other pipeline;

The main machine is respectively connected with the ammonia treatment unit (12) and the ammonia water collecting cabinet (18) through pipelines, the ammonia treatment unit is connected with the ventilation mast (13), a second remote control valve (10) and an ammonia concentration transmitter (11) are arranged on a passage of the main machine, which is communicated with the ammonia treatment unit, and a pressure transmitter (16) and a fourth remote control valve (17) are arranged on a passage of the main machine, which is communicated with the ammonia water collecting cabinet;

the host is connected with a fresh water buffer tank (7), and a fresh water transfer pump (15) and a third remote control valve (14) are arranged on the passage of the fresh water buffer tank to the host.

2. A zero ammonia residual ship liquid ammonia feed purge system according to claim 1, wherein the storage pressure of the nitrogen low pressure tank is 10barg.

3. A zero ammonia residual ship liquid ammonia feed purge system according to claim 1, wherein the storage pressure of the nitrogen high pressure tank is 30barg.

4. The zero ammonia residue ship liquid ammonia supply purge system of claim 1, wherein the inlet of the electric heater is provided with a pressure regulating valve.

5. The zero ammonia residual ship liquid ammonia supply and removal system of claim 1, wherein the central control system controls a fresh water transfer pump, a first remote control valve, a second remote control valve, a third remote control valve, a fourth remote control valve, and a fifth remote control valve.

6. The zero ammonia residual ship liquid ammonia supply purge system of claim 1, wherein the first remote control valve and the second remote control valve are closed when the ammonia concentration in the ammonia concentration transmitter monitoring line drops to 300 ppm.

7. The zero ammonia residual ship liquid ammonia supply purge system of claim 1, wherein the fifth remote control valve and the second remote control valve are closed when the ammonia concentration in the ammonia concentration transmitter monitoring line falls below 1 ppm.

8. The zero ammonia residual ship liquid ammonia feed purge system of claim 4 wherein the pressure regulator valve regulates low pressure nitrogen to 5barg before sending to the electric heater for heating to 70 ℃.