A Ship Engine Exhaust Gas Residual Heat Water Treatment System and Working Method

Abstract

The present invention discloses a waste heat water treatment system and working method for a ship engine, which relates to the technical field of ship waste gas treatment, solves the problems of low utilization rate and large volume of the existing ship waste gas reuse system, reduces the occupation of the working space of the ship, and the specific scheme is as follows: It includes a waste heat steam generator and a water tank. The intake end of the waste heat steam generator is connected to the exhaust pipe, and the outlet end is connected to the EGC for preliminary heat exchange with the waste gas. The water outlet of the EGC is connected to the water tank through a pipeline. One side of the water tank is connected to a heat exchanger through a pipeline, and the other side is connected to the waste heat steam generator through a pipeline. The steam outlet of the waste heat steam generator is connected to a steam generator, a condenser, and a waste heat boiler through pipelines respectively. The water outlet of the waste heat steam generator is connected to a residue tank through a pipeline. The outlet end of the steam generator is connected to the condenser through a pipeline. The water outlet of the condenser is connected to the water tank and the ocean through pipelines respectively.

Description

Technical Field

[0001] The present invention relates to the technical field of ship exhaust gas treatment, and particularly to a ship engine exhaust gas waste heat water treatment system and a working method thereof. Background Art

[0002] In order to expand the operation window of a low-pressure intake dual-fuel engine, reduce methane emissions, reduce fuel consumption, and improve engine performance, intelligent exhaust gas recirculation control technology has begun to be widely adopted. The exhaust gas is washed and cooled by an exhaust gas cooler (EGC), and various pollutants such as oil, acid, and particulate matter may be generated in the circulating water tank. A water treatment device is used to treat the cooling water to a certain standard and then discharge it into the sea.

[0003] The inventor found that most of the existing exhaust gas recirculation technologies recover the exhaust gas waste heat for heating and other scenarios, with a single energy utilization scenario and low utilization rate; most of the existing exhaust gas recirculation technologies directly spray and cool the exhaust gas, and most of the exhaust gas waste heat is absorbed by seawater and discharged into the sea, resulting in a waste of energy; at the same time, since the maximum exhaust gas circulation volume can reach 50% of the total exhaust gas volume, and the exhaust gas temperature at the outlet of the turbocharger is about 190°C to 240°C, when the exhaust gas directly enters the EGC, the high-temperature exhaust gas will increase the workload of the EGC, the circulating cooling water heat exchanger, etc., and then cause the volume of the EGC, the water treatment equipment, etc. to increase, increasing the occupation of the ship's working space. Summary of the Invention

[0004] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide a ship engine exhaust gas waste heat water treatment system and a working method thereof, which are provided with a waste heat steam generator, can greatly reduce the exhaust gas temperature entering the EGC, reduce the workload of the EGC, thereby reducing the volume of the EGC. At the same time, the waste heat steam generator can utilize and transport the exhaust gas waste heat, greatly reducing the workload of the heat exchanger, and then synchronously reducing the volume of the heat exchanger, solving the problems of low utilization rate and large volume of the existing ship exhaust gas reuse system.

[0005] In order to achieve the above purpose, the present invention is realized by the following technical solutions:

[0006] In a first aspect, the present invention provides a waste heat water treatment system for a ship engine, including a waste heat steam generator and a water tank. The intake end of the waste heat steam generator is connected to the exhaust pipe, and the outlet end is connected to the EGC for preliminary heat exchange with the exhaust gas. The water outlet of the EGC is connected to the water tank through a pipeline. One side of the water tank is connected to a heat exchanger through a pipeline, and the other side is connected to the waste heat steam generator through a pipeline. The steam outlet of the waste heat steam generator is connected to a steam generator, a condenser, and a waste heat boiler through pipelines respectively. The water outlet of the waste heat steam generator is connected to a residue tank through a pipeline. The outlet end of the steam generator is connected to the condenser through a pipeline. The water outlet of the condenser is connected to the water tank and the ocean through pipelines respectively.

[0007] As a further implementation method, the water flow in the pipeline is driven by a water pump, and solenoid valves are provided at each pipeline and pipeline branch.

[0008] As a further implementation method, an alkali solution tank is also provided on the pipeline connecting the EGC and the water tank. The water discharged from the EGC flows into the water tank after heat exchange with the solution in the alkali solution tank. The alkali solution tank is also connected to the water tank through a pipeline to adjust the pH value in the water tank. A third sensor for monitoring the pH value is provided on the alkali solution tank.

[0009] As a further implementation method, a branch pipeline is provided on the pipeline connecting the water tank and the waste heat steam generator. A sewage processor is installed on the branch pipeline. The water tank is directly connected to the waste heat steam generator through a pipeline or connected to the waste heat steam generator through the sewage processor.

[0010] As a further implementation method, the sewage processor is connected to the residue tank through a pipeline.

[0011] As a further implementation method, a first water circulation pipeline is provided on the water tank. A first sensor for monitoring oil content and pH value is provided on the first water circulation pipeline. A second sensor for monitoring the liquid level is also provided on the water tank. A fourth sensor for monitoring the temperature is installed on the pipeline at the steam outlet of the waste heat steam generator. A fifth sensor for monitoring the liquid level height and a sixth sensor for monitoring salinity - turbidity are installed on the waste heat steam generator.

[0012] As a further implementation method, the waste heat steam generator is composed of a shell and evaporation tubes and an atomizer arranged inside the shell. The atomizer is located above the evaporation tubes. The atomizer is connected to the inside of the shell through a second water circulation pipeline. The two ends of the evaporation tubes are respectively connected to the exhaust pipe and the EGC. The outer wall of the evaporation tubes is a porous structure.

[0013] In a second aspect, the present invention provides a working method for a waste heat water treatment system of a ship engine, which is specifically as follows:

[0014] The waste gas first flows through the waste heat steam generator via the exhaust pipe for preliminary heat exchange. The heat of the waste gas is transferred to the water to be treated pre-stored at the bottom of the waste heat steam generator to generate steam. After preliminary heat exchange, the waste gas enters the EGC for secondary heat exchange and cooling, and then is discharged into the water tank.

[0015] Determine the flow direction of the water to be treated based on the liquid level heights in the water tank and the waste heat steam generator, as well as the oil content of the water to be treated in the water tank. Control the water to be treated with an oil content less than the specified value in the water tank to directly flow to the heat exchanger / waste heat steam generator, or control the water to be treated with an oil content greater than the specified value in the water tank to flow to the waste heat evaporation generator after passing through the sewage treatment device.

[0016] Determine the flow direction of the steam according to the steam temperature, so that the steam with a temperature higher than the limit value flows to the steam generator to generate electricity and do work. The exhausted steam after work enters the condenser for condensation and flows back into the water tank or is discharged into the ocean; the steam with a temperature lower than the limit value directly enters the waste heat boiler / flows to the condenser for condensation and flows back into the water tank or is discharged into the ocean.

[0017] As a further implementation method, monitor the pH value of the water to be treated in the water tank, and use the alkali liquid tank to adjust the pH value of the water to be treated in the water tank.

[0018] As a further implementation method, monitor the salt content or turbidity of the water body in the waste heat steam generator. When the salt content or turbidity is higher than the limit value, directly discharge it into the residue tank and replenish water through the water tank; the substances containing oil and particulate matter in the sewage treatment device are also discharged into the residue tank.

[0019] The beneficial effects of the present invention are as follows:

[0020] (1) The present invention is provided with a waste heat steam generator, which can greatly reduce the temperature of the waste gas entering the EGC, reduce the workload of the EGC, thereby reducing the volume of the EGC. At the same time, the waste heat steam generator can utilize the waste heat of the waste gas to generate steam and transport it for different operations, realizing the multi-stage utilization of the waste heat of the waste gas. While improving the utilization rate of the waste heat of the waste gas, it greatly reduces the workload of structures such as heat exchangers, and further reduces the overall volume of the water treatment system.

[0021] (2) An alkali liquid tank is also provided on the pipeline connecting the EGC and the water tank. The water discharged from the EGC flows into the water tank after heat exchange with the solution in the alkali liquid tank, ensuring the full dissolution of NaOH in the alkali liquid tank and preventing crystallization. The alkali liquid tank is also connected to the water tank through a pipeline to adjust the pH value in the water tank, ensuring that the water to be treated discharged from the water tank meets the discharge requirements. Description of the Drawings

[0022] The accompanying drawings forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments and descriptions thereof of the present invention are used to explain the present invention and do not constitute an improper limitation to the present invention.

[0023] Figure 1 is a schematic diagram of the overall structure of a ship engine exhaust waste heat treatment system according to one or more embodiments of the present invention;

[0024] In the figure: The distances or dimensions between each part are exaggerated for showing the positions of each part, and the schematic diagram is only for illustration;

[0025] Among them, 1. water tank; 2. lye tank; 3. heat exchanger; 4. sewage processor; 5. waste heat steam generator; 5-1. outer shell; 5-2. evaporation tube; 5-3. atomizer; 6. steam generator; 7. condenser; 8. residue tank; 9. electric control cabinet;

[0026] Water pumps: 10-1. first water pump; 10-2. second water pump; 10-3. third water pump; 10-4. fourth water pump; 10-5. fifth water pump; 10-6. sixth water pump; 10-7. seventh water pump; 10-8. eighth water pump; 10-9. ninth water pump;

[0027] Solenoid valves: 11-1. first solenoid valve; 11-2. second solenoid valve; 11-3. third solenoid valve; 11-4. fourth solenoid valve; 11-5. fifth solenoid valve; 11-6. sixth solenoid valve; 11-7. seventh solenoid valve; 11-8. eighth solenoid valve; 11-9. ninth solenoid valve; 11-10. tenth solenoid valve; 11-11. eleventh solenoid valve; 11-12. twelfth solenoid valve; 11-13. thirteenth solenoid valve;

[0028] Sensors: 12-1. first sensor; 12-2. second sensor; 12-3. third sensor; 12-4. fourth sensor; 12-5. fifth sensor; 12-6. sixth sensor;

[0029] Pipeline: 13-1, the first pipeline; 13-2, the second pipeline; 13-3, the third pipeline; 13-4, the fourth pipeline; 13-5, the fifth pipeline; 13-6, the sixth pipeline; 13-7, the seventh pipeline; 13-8, the eighth pipeline; 13-9, the ninth pipeline; 13-10, the tenth pipeline; 13-11, the eleventh pipeline; 13-12, the twelfth pipeline; 13-13, the thirteenth pipeline; 13-14, the fourteenth pipeline; 13-15, the fifteenth pipeline; 13-16, the sixteenth pipeline; 13-17, the seventeenth pipeline; 13-18, the eighteenth pipeline; 13-19, the nineteenth pipeline; 13-20, the twentieth pipeline; 13-21, the twenty-first pipeline; 13-22, the twenty-second pipeline; 13-23, the twenty-third pipeline; 13-24, the twenty-fourth pipeline; 13-25, the twenty-fifth pipeline. Detailed implementation mode

[0030] It should be noted that the following detailed description is illustrative and aims to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs.

[0031] As introduced in the background technology, the maximum amount of exhaust gas recirculation can reach 50% of the total exhaust gas volume, and the exhaust gas temperature at the outlet of the turbocharger is about 190°C - 240°C. If the exhaust gas is directly sprayed and cooled without installing an economizer and using conventional water treatment equipment, most of the waste heat of the exhaust gas is absorbed by seawater and discharged into the sea, resulting in waste of energy; at the same time, when the exhaust gas directly enters the EGC, the high-temperature exhaust gas will increase the workload of the EGC, the circulating cooling water heat exchanger, etc., and then lead to the problem of increasing the volume of the EGC, the water treatment equipment, etc. To solve the above technical problems, the present invention proposes a ship engine exhaust gas waste heat water treatment system and working method.

[0032] Embodiment 1

[0033] In a typical implementation mode of the present invention, as Figure 1 shown, a ship engine exhaust gas waste heat water treatment system is proposed, including a water tank 1, an alkali solution tank 2, a heat exchanger 3, a sewage processor 4, a waste heat steam generator 5, a steam generator 6, a condenser 7, a residue tank 8, and an electric control cabinet 9.

[0034] The water inlet of the alkali solution tank 2 is connected to the EGC through the first pipeline 13-1 to receive the exhaust gas washing water generated by the EGC. The water outlet of the alkali solution tank 2 is connected to the water inlet of the water tank 1 through the sixth pipeline 13-6. A third solenoid valve 11-3 and a third water pump 10-3 are installed on the sixth pipeline 13-6 to be used for injecting NaOH solution into the water tank 1.

[0035] The lye tank 2 is used to hold the NaOH solution with a concentration of 50%. A seventh pipeline 13-7 is also connected to the water inlet of the lye tank 2, which is mainly used for the addition of the NaOH solution. The outside of the lye tank 2 is coated with a heat-insulating layer to reduce the heat loss of the waste gas washing water. A third sensor 12-3 is also installed on the lye tank 2 to monitor the acidity and alkalinity of the internal solution. A heat exchange tube row is installed in the lye tank 2. Before the waste gas washing water enters the water tank 1 from the EGC, it first transfers a part of its heat to the NaOH solution through the heat exchange tube row to ensure the full dissolution of the NaOH and prevent crystallization from occurring, and then is discharged into the water tank 1 through the heat exchange tube row.

[0036] A first water circulation pipeline (i.e., Figure 1 the fifth pipeline 13-5 in it) is installed on the side wall of the water tank 1. A first sensor 12-1, a second solenoid valve 11-2 and a second water pump 10-2 are installed on the fifth pipeline 13-5. Among them, the first sensor 12-1 is an oil content - pH sensor, which is mainly used to monitor the oil content and acidity and alkalinity of the liquid in the water tank 1. A second sensor 12-2 is also installed on the side wall of the water tank 1. The second sensor 12-2 is a liquid level sensor, which is mainly used to monitor the liquid level in the water tank 1.

[0037] The water outlet of the water tank 1 is connected to the water inlet of the heat exchanger 3 through a second pipeline 13-2. A first water pump 10-1 and a first solenoid valve 11-1 are installed on the second pipeline 13-2, which can exchange heat with the heat exchanger 3, so as to use the seawater in the heat exchanger 3 to take away the heat of the water to be treated in the water tank 1. The cooled water to be treated returns to the EGC as cooling water. The seawater inlet of the heat exchanger 3 is connected to the third pipeline 13-3, and the seawater outlet is connected to the fourth pipeline 13-4.

[0038] It can be understood that the water tank 1 is also insulated to prevent the liquid in the water tank 1 from exchanging heat with the external environment and causing heat loss.

[0039] The water outlet of the water tank 1 is also connected to the water inlet of the sewage processor 4 through an eighth pipeline 13-8. The sewage processor 4 is an existing membrane type sewage processor, which is mainly used to treat the oil content and particulate matter in the water transported from the water tank 1.

[0040] A fourth solenoid valve 11-4, a sixth solenoid valve 11-6 and a fourth water pump 10-4 are installed on the eighth pipeline 13-8. Among them, the fourth solenoid valve 11-4 is used to control the on-off of the eighth pipeline 13-8. The sixth solenoid valve 11-6 is of a three-way structure, one end is connected to the eighth pipeline 13-8, one end is connected to the water inlet of the sewage processor 4, and the other end is successively connected with a seventh solenoid valve 11-7, an eleventh pipeline 13-11 and a waste heat steam generator 5.

[0041] The water outlet of the sewage processor 4 is connected to the seventh solenoid valve 11-7 through the tenth pipeline 13-10, and then connected to the water inlet of the waste heat steam generator 5 through the eleventh pipeline 13-11. Thus, the flow direction of the water discharged from the water tank 1 can be controlled under the action of the sixth solenoid valve 11-6, that is, directly flowing to the waste heat steam generator 5 or first flowing through the sewage processor 4 for oil pollution treatment and then flowing to the waste heat steam generator 5.

[0042] The waste heat steam generator 5 mainly consists of a shell 5-1, evaporation pipes 5-2, and an atomizer 5-3. The shell 5-1 is made of stainless steel and is covered with a heat insulation layer on the outside. Both the evaporation pipes 5-2 and the atomizer 5-3 are installed inside the shell 5-1; the atomizer 5-3 is located above the evaporation pipes 5-2 and is used to atomize and spray the water inside the shell 5-1 onto the evaporation pipes 5-2.

[0043] The evaporation pipes 5-2 are components that cause the water to be treated to boil and evaporate. The intake end of the evaporation pipes 5-2 is connected to the exhaust pipe after the turbocharger through the thirteenth pipeline 13-13, and the outlet end is connected to the EGC through the fourteenth pipeline 13-14. The inner surface of the evaporation pipes 5-2 is in contact with the exhaust gas, and the outer surface is in contact with the water to be treated.

[0044] The inner wall of the evaporation pipes 5-2 is made of a material with high thermal conductivity and corrosion resistance, and its inner diameter is the same as the exhaust pipe it is connected to; the outer wall of the evaporation pipes 5-2 is made into a layer of high-thermal-conductivity porous structure by the method of ionization deposition. The porous structure increases the vaporization nuclei on the surface of the evaporation pipes 5-2, achieving the purpose of strengthening boiling heat transfer and greatly improving the evaporation efficiency. The atomizer 3-3 consists of a spray gun body and multiple atomizing nozzles installed on the spray gun body. The spray gun body is connected to the bottom of the shell 5-1 through the twelfth pipeline 13-12.

[0045] The fifteenth pipeline 13-15 is installed at the steam outlet at the upper part of the shell 5-1, the twelfth pipeline 13-12 and the fifth sensor 12-5 are installed on the side, and the fifth sensor 12-5 is used to monitor the liquid level height inside the waste heat steam generator 5. The twenty-first pipeline 13-21 and the twenty-second pipeline 13-22 are installed at the bottom.

[0046] Among them, the fifteenth pipeline 13-15 is a steam pipeline, and the fourth sensor 12-4 is installed on the fifteenth pipeline 13-15. The fourth sensor 12-4 is a temperature sensor. The fifteenth pipeline 13-15 is connected to the tenth solenoid valve 11-10. The tenth solenoid valve 11-10 has a three-way structure, and the fifteenth pipeline 13-15 is respectively connected to the evaporation generator 6 and the external environment through the tenth solenoid valve 11-10;

[0047] The twelfth pipeline 13-12 is the second water circulation pipeline. An eighth water pump 10-8 and a ninth solenoid valve 11-9 are installed on the twelfth pipeline 13-12. One end of the twelfth pipeline 13-12 is connected to the bottom of the housing 5-1, and the other end is connected to the atomizer 5-3, so as to circulate and atomize the water in the housing 5-1;

[0048] The twenty-first pipeline 13-21 is the salinity-turbidity measurement pipeline. A sixth sensor 12-6 and a seventh water pump 10-7 are installed on the twenty-first pipeline 13-21. The sixth sensor 12-6 is a salinity-turbidity sensor, and the seventh water pump 10-7 is a diaphragm pump;

[0049] The twenty-second pipeline 13-22 is the concentrated liquid discharge pipeline. A sixth water pump 10-6 and an eighth solenoid valve 11-8 are installed on the twenty-second pipeline 13-22. The sixth water pump 10-6 is a diaphragm pump. The waste heat steam generator 5 is connected to the residue tank 8 through the twenty-second pipeline 13-22 for discharging the concentrated liquid.

[0050] The fifteenth pipeline 13-15 on the waste heat steam generator 5 is respectively connected to the evaporation generator 6 and the external environment through the tenth solenoid valve 11-10. Specifically, the tenth solenoid valve 11-10 has a tee structure, one end is connected to the fifteenth pipeline 13-15, one end is connected to the evaporation generator 6 through the sixteenth pipeline 13-16 (working steam inlet pipeline), and one end is connected to the waste heat boiler through the seventeenth pipeline 13-17, the eleventh solenoid valve 11-11, and the twentieth pipeline 13-20 in sequence.

[0051] The setting of the waste heat steam generator 5 can greatly reduce the temperature of the exhaust gas entering the EGC, reduce the workload of the EGC, thereby reducing the volume of the EGC. At the same time, the waste heat steam generator 5 can utilize and transport the waste heat of the exhaust gas, greatly reducing the workload of the heat exchanger 3, and further reducing the volume of the heat exchanger 3 synchronously.

[0052] The steam generator 6 is an existing oil-free screw expansion evaporation generator, which can generate electricity using low-temperature and low-pressure saturated or superheated steam as the working medium, and the generated electric energy is connected to the ship's power grid. The evaporation generator 6 is connected to the condenser 7 through the eighteenth pipeline 13-18 (exhaust steam outlet pipeline) and the twelfth solenoid valve 11-12; the waste heat steam generator 5 is also connected to the condenser 7. Specifically, the waste heat steam generator 5 is connected to the condenser 7 through the fifteenth pipeline 13-15, the tenth solenoid valve 11-10, the seventeenth pipeline 13-17, the eleventh solenoid valve 11-11, the nineteenth pipeline 13-19, and the twelfth solenoid valve 11-12 for condensing and recycling the steam.

[0053] The condenser 7 is mainly used to condense the exhaust steam from the outlet of the steam generator 6 or the low-pressure saturated steam discharged from the waste heat evaporation generator 5, and is transported and distributed by the ninth water pump 10-9 along the twenty-third pipeline 13-23.

[0054] Specifically, the water outlet of the condenser 7 is connected to the thirteenth solenoid valve 11-13 through the twenty-third pipeline 13-23. The thirteenth solenoid valve 11-13 is a three-way structure, one end is connected to the twenty-third pipeline 13-23, one end is connected to the water tank 1 through the twenty-fifth pipeline 13-25, and one end is connected to the external environment (ocean) through the twenty-fourth pipeline 13-24.

[0055] The residue tank 8 is not only connected to the waste heat steam generator 5 through the twenty-second pipeline 13-22, but also sequentially connected to the sewage treatment device 4 through the twenty-sixth pipeline 13-26, the fifth solenoid valve 11-5, the fifth water pump 10-5, and the twenty-fifth pipeline 13-25. It is mainly used to store residues containing substances such as oil, particulate matter, and salt generated by the waste heat steam generator 5 and the sewage treatment device 4.

[0056] The electric control cabinet 9 is connected to each sensor, water pump, and solenoid valve, and is used to receive signals from each sensor, control the opening and closing of each water pump and solenoid valve, and thus control the operation process of the entire exhaust gas and waste heat water treatment system.

[0057] Embodiment 2

[0058] In another typical implementation manner of the present invention, a working method for an exhaust gas and waste heat water treatment system of a ship engine is proposed, which is specifically as follows:

[0059] (1) Generation and pH adjustment of the water to be treated

[0060] After the dual-fuel engine runs, start the exhaust gas recirculation system. A part of the exhaust gas drawn from behind the turbocharger first flows through the waste heat steam generator 5 through the exhaust pipe and the thirteenth pipeline 13-13 for preliminary heat exchange. The heat of the exhaust gas is transferred to the water to be treated pre-stored at the bottom of the waste heat steam generator 5 through the evaporation tube 5-2;

[0061] The pre-stored water to be treated is in full contact with the evaporation tube 5-2, and the liquid level is between the minimum and maximum liquid level limits. The water to be treated is heated and evaporated to generate water vapor. After passing through the waste heat steam generator 5, the exhaust gas enters the EGC along the fourteenth pipeline 13-14. The exhaust gas is in contact with the cooling water for secondary heat exchange, and the temperature drops. Pollutants contained in the exhaust gas, such as sulfur oxides, polycyclic aromatic hydrocarbons, particulate matter, and other pollutants enter the cooling water. The cooling water first passes through the heat exchange tube row in the lye tank 2 along the first pipeline 13-1 and then enters the water tank 1 to become the water to be treated;

[0062] In the water tank 1, the first sensor 12-1 on the fifth pipeline 13-5 monitors the oil content and pH value of the water to be treated at a relatively high frequency. If the pH value is less than the specified value, the electric control cabinet 9 issues a control instruction to turn on the third water pump 10-3 and the third solenoid valve 11-3 to add an appropriate amount of NaOH solution to the water tank 1 to ensure that the pH value of the cooling water to be treated meets the requirements of relevant emission regulations.

[0063] (2) Removal of oil from the water to be treated

[0064] In the water tank 1, the first sensor 12-1 on the fifth pipeline 13-5 monitors the oil content and pH value of the water to be treated at a high frequency.

[0065] If the oil content of the water to be treated is less than the specified value and the liquid level in the water tank 1 exceeds the highest liquid level limit, the electric control cabinet 9 issues a control instruction to turn on the fourth water pump 10-4 and the fourth solenoid valve 11-4, and open the corresponding channels of the sixth solenoid valve 11-6 and the seventh solenoid valve 11-7. A certain amount of the water to be treated in the water tank 1 is successively transported along the eighth pipeline 13-8, the ninth pipeline 13-9, and the eleventh pipeline 13-11 to the waste heat steam generator 5 until the water level in the waste heat steam generator 5 reaches the highest liquid level limit or the liquid level in the water tank 1 approaches the lowest liquid level limit, and the relevant solenoid valves and water pumps return to the closed state;

[0066] When the oil content of the water to be treated is less than the specified value, if the liquid level in the water tank 1 exceeds the highest liquid level limit and the water level in the waste heat steam generator 5 reaches the highest liquid level limit, the first water pump 10-1 and the first solenoid valve 11-1 are turned on, so that the water to be treated in the water tank 1 flows into the heat exchanger 3 through the second pipeline 13-2 for heat transfer and utilization.

[0067] If the oil content of the water to be treated is greater than the specified value and the liquid level in the water tank 1 exceeds the highest liquid level limit, the electric control cabinet 9 issues a control instruction to turn on the fourth water pump 10-4 and the fourth solenoid valve 11-4, and open the corresponding channels of the sixth solenoid valve 11-6 and the seventh solenoid valve 11-7. The water to be treated flows successively along the eighth pipeline 13-8, the tenth pipeline 13-10, and the eleventh pipeline 13-11. The water to be treated first passes through the membrane type sewage processor 4 to remove the oil and particulate matter in the water, and then enters the waste heat steam generator 5 until the water level in the waste heat steam generator 5 reaches the highest liquid level limit or the liquid level in the water tank 1 approaches the lowest liquid level limit, and the relevant solenoid valves and water pumps return to the closed state.

[0068] (3) Evaporation and salt removal of the water to be treated

[0069] If the water level in the waste heat steam generator 5 is between the minimum and maximum level limits, the electric control cabinet 9 issues a control command to turn on the eighth water pump 10-8 and the ninth solenoid valve 11-9, causing the water to be treated to circulate through the twelfth pipeline 13-12, the atomizer 5-3, and the waste heat steam generator 5. Inside the waste heat steam generator 5, the water to be treated is atomized by the atomizer 5-3 and sprayed onto the surface of the evaporation pipe 5-2, and the water to be treated will continuously evaporate into water vapor.

[0070] After continuous evaporation, if the water level in the waste heat steam generator 5 is lower than the minimum level limit, the electric control cabinet 9 issues a control command to turn on the seventh water pump 10-7, and the sixth sensor 12-6 is used to measure the salt content and turbidity of the remaining concentrate inside the housing 5-1.

[0071] If the salt content or turbidity is higher than the limit value, turn on the sixth water pump 10-6 and the eighth solenoid valve 11-8, discharge the remaining concentrate into the residue cabinet 8 through the twenty-second pipeline 13-22, and use the water tank 1 to supplement the water body;

[0072] If the salt content or turbidity is lower than the limit value, and the water level in the water tank 1 exceeds the maximum level limit, turn on the fourth water pump 10-4 and the fourth solenoid valve 11-4, open the corresponding channels of the sixth solenoid valve 11-6 and the seventh solenoid valve 11-7. The water to be treated in the water tank 1 is successively transported along the eighth pipeline 13-8, the ninth pipeline 13-9 (or 13-10, judged according to the oil content of the water to be treated), and the eleventh pipeline 13-11 to the waste heat steam generator 5 to transport a certain amount of water to be treated until the water level in the waste heat steam generator 5 reaches the maximum level limit or the water level in the water tank 1 is close to the minimum level limit.

[0073] (4) Treatment and distribution of water vapor

[0074] After the fourth sensor 12-4 measures the temperature, if the temperature of the water vapor generated in the waste heat steam generator 5 is higher than the limit value, it is considered that the saturated steam has strong work capacity, and this part of the water vapor can be used for power generation.

[0075] At this time, the electric control cabinet 9 issues a control command to open the corresponding channels of the tenth solenoid valve 11-10 and the twelfth solenoid valve 11-12. The saturated steam successively enters the steam generator 6 through the fifteenth pipeline 13-15 and the sixteenth pipeline 13-16 to do work and generate electricity. The generated electric energy is connected to the ship's power grid, and the exhausted steam after doing work in the steam generator 6 enters the condenser 7 through the eighteenth pipeline 13-18 and changes from the unsaturated wet steam state to the condensate state.

[0076] If the water level in the water tank 1 is lower than the minimum level limit, open the corresponding channels of the ninth water pump 10-9 and the thirteenth solenoid valve 11-13, and the condensate enters the water tank 1 as supplementary fresh water through the twenty-third pipeline 13-23 and the twenty-fifth pipeline 13-25;

[0077] If the liquid level in the water tank 1 is higher than the minimum liquid level limit value, the corresponding channels of the ninth water pump 10-9 and the thirteenth solenoid valve 11-13 are opened, and the condensed water is discharged into the sea through the twenty-third pipeline 13-23 and the twenty-fourth pipeline 13-24.

[0078] After the temperature is measured by the fourth sensor 12-4, if the temperature of the water vapor generated in the waste heat steam generator 5 is lower than the limit value, it is considered that the energy for the saturated steam to do work is weak. Depending on the demand, the water vapor generated at this time can be used as supplementary saturated steam for the ship's waste heat boiler, supplementary fresh water for the water tank 1, or directly discharged as waste water.

[0079] If the liquid level in the water tank 1 is lower than the minimum liquid level limit value, the electric control box 9 issues a control instruction to open the corresponding channels of the tenth solenoid valve 11-10, the eleventh solenoid valve 11-11, the twelfth solenoid valve 11-12, and the thirteenth solenoid valve 11-13, and turn on the ninth water pump 10-9. The saturated steam enters the condenser 7 along the fifteenth pipeline 13-15, the seventeenth pipeline 13-17, and the nineteenth pipeline 13-19 to become condensed water, and then enters the water tank 1 as supplementary fresh water through the twenty-third pipeline 13-23 and the twenty-fifth pipeline 13-25;

[0080] If the liquid level in the water tank 1 is higher than the minimum liquid level limit value and the ship's waste heat boiler requires more saturated steam, the corresponding channels of the tenth solenoid valve 11-10 and the eleventh solenoid valve 11-11 are opened, and the saturated steam enters the steam drum of the waste heat boiler along the fifteenth pipeline 13-15, the seventeenth pipeline 13-17, and the twentieth pipeline 13-20;

[0081] If the liquid level in the water tank 1 is higher than the minimum liquid level limit value and the ship's waste heat boiler does not require more saturated steam, the corresponding channels of the tenth solenoid valve 11-10, the eleventh solenoid valve 11-11, the twelfth solenoid valve 11-12, and the thirteenth solenoid valve 11-13 are opened, and the ninth water pump 10-9 is turned on. The saturated steam enters the condenser 7 along the fifteenth pipeline 13-15, the seventeenth pipeline 13-17, and the nineteenth pipeline 13-19 to become condensed water, and then is discharged into the sea through the twenty-third pipeline 13-23 and the twenty-fourth pipeline 13-24.

[0082] (5) Treatment of residues in the sewage processor 4 and the waste heat steam generator 5

[0083] The substances containing oil and particulate matter generated in the sewage processor 4 will be discharged into the residue tank 8 through the twenty-sixth pipeline 13-26; at the same time, the concentrate containing salts and particulate matter generated in the waste heat steam generator 5 will be discharged into the residue tank 8 through the twenty-second pipeline 13-22.

[0084] Through the above operations, not only can wastewater containing oil, acidic substances, salts and particulate matter be treated, and the pH value of the wastewater can be adjusted, but also a part of electric energy can be generated by steam or used as supplementary saturated steam for the waste heat boiler of the ship, greatly improving the utilization of the waste heat of the ship engine exhaust gas.

[0085] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, various modifications and changes can be made to the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A waste heat water treatment system for a ship engine, characterized in that, it includes a waste heat steam generator and a water tank. The intake end of the waste heat steam generator is connected to the exhaust pipe, and the outlet end is connected to the EGC for preliminary heat exchange with the exhaust gas. The water outlet of the EGC is connected to the water tank through a pipeline. One side of the water tank is connected to the heat exchanger through a pipeline, and the other side is connected to the waste heat steam generator through a pipeline. The heat exchanger has a seawater inlet and a seawater outlet. The water to be treated in the water tank exchanges heat with the seawater in the heat exchanger and then returns to the EGC. The steam outlet of the waste heat steam generator is connected to a steam generator, a condenser, and a waste heat boiler through pipelines respectively. The water outlet of the waste heat steam generator is connected to a residue tank through a pipeline. The outlet end of the steam generator is connected to the condenser through a pipeline. The water outlet of the condenser is connected to the water tank and the ocean through pipelines respectively; a lye tank is also provided on the pipeline connecting the EGC and the water tank. The water discharged from the EGC flows into the water tank after exchanging heat with the solution in the lye tank. The lye tank is also connected to the water tank through a pipeline to adjust the pH value in the water tank. A third sensor for monitoring the pH value is provided on the lye tank; a branch pipeline is provided on the pipeline connecting the water tank and the waste heat steam generator. A sewage processor is installed on the branch pipeline. The water tank is directly connected to the waste heat steam generator through a pipeline or connected to the waste heat steam generator through the sewage processor; the sewage processor is connected to the residue tank through a pipeline; a first water circulation pipeline is provided on the water tank. A first sensor for monitoring oil content and pH value is provided on the first water circulation pipeline. A second sensor for monitoring the liquid level is also provided on the water tank. A fourth sensor for monitoring the temperature is installed on the pipeline at the steam outlet of the waste heat steam generator. A fifth sensor for monitoring the liquid level height and a sixth sensor for monitoring salt content and turbidity are installed on the waste heat steam generator; the waste heat steam generator is composed of a shell and evaporation pipes and atomizers arranged inside the shell. The atomizer is located above the evaporation pipes. The atomizer is connected to the inside of the shell through a second water circulation pipeline. The two ends of the evaporation pipes are respectively connected to the exhaust pipe and the EGC. The outer wall of the evaporation pipes is a porous structure; the water flow in each pipeline is driven by a water pump, and solenoid valves are provided at each pipeline and pipeline branch. The electric control cabinet is connected to each sensor, water pump, and solenoid valve, and is used to receive the signals of each sensor, control the opening and closing of each water pump and solenoid valve, and thus control the operation process of the entire waste heat water treatment system for exhaust gas.

2. A working method of the waste heat water treatment system for a ship engine according to claim 1, characterized in that, specifically as follows: the exhaust gas first flows through the waste heat steam generator through the exhaust pipe for preliminary heat exchange. The heat of the exhaust gas is transferred to the water to be treated pre-stored at the bottom of the waste heat steam generator to generate steam. The water to be treated in the water tank exchanges heat with the seawater in the heat exchanger and then enters the EGC as cooling water for secondary heat exchange with the exhaust gas after preliminary heat exchange. The water to be treated after secondary heat exchange is discharged into the water tank; Determine the flow direction of the water to be treated based on the liquid level heights in the water tank and the waste heat steam generator and the oil content of the water to be treated in the water tank, and control the water to be treated with an oil content less than the specified value in the water tank to directly flow to the heat exchanger / waste heat steam generator or control the water to be treated with an oil content greater than the specified value in the water tank to flow to the waste heat steam generator after passing through the sewage processor; Determine the flow direction of the steam based on the steam temperature, so that the steam with a temperature higher than the limit value flows to the steam generator to generate electricity and do work, and the exhausted steam after doing work enters the condenser to be condensed and flows back to the water tank or is discharged into the ocean; so that the steam with a temperature lower than the limit value directly enters the waste heat boiler / flows to the condenser to be condensed and flows back to the water tank or is discharged into the ocean.

3. The working method of a ship engine exhaust gas waste heat water treatment system according to claim 2, characterized in that, Monitor the pH value of the water to be treated in the water tank, and use the alkali liquid tank to adjust the pH value of the water to be treated in the water tank.

4. The working method of a ship engine exhaust gas waste heat water treatment system according to claim 2, characterized in that, Monitor the salt content or turbidity of the water body in the waste heat steam generator, and directly discharge it into the residue tank and replenish water to the water tank when the salt content or turbidity is higher than the limit value; the substances containing oil and particulate matter in the sewage processor are also discharged into the residue tank.

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