CN108860550B - Double-power supply and propulsion system for LNG power ship and working method - Google Patents

Abstract

The invention discloses a dual power supply and propulsion system and a working method for an LNG powered ship. The system includes an LNG power supply subsystem and an electric power supply subsystem. After the LNG is pressurized to supercritical pressure by the booster pump, the LNG is heated into ultra-high pressure and high temperature natural gas by using seawater and the cooling water of the ship's main engine cylinder liner as heat sources, and the natural gas expands in the turbine to do work, and drives the generator to generate electricity as the ship sails. At the same time, the natural gas expanded in the turbine enters the ship's main engine system to be burned as another power for the ship's navigation, so that the LNG-powered ship can choose electric drive or gas drive according to different sailing conditions. The invention makes full use of the waste heat released after the combustion of seawater and LNG as the heat source for LNG regasification and turbine power generation, which not only further improves the utilization efficiency of LNG cold energy and heat energy, but also significantly reduces the traditional LNG power ship when sailing. The cold and thermal energy discharged to the environment maximizes the protection of the marine and atmospheric environment.

Description

A dual power supply and propulsion system and working method for an LNG powered ship

technical field

The invention relates to a dual power supply and propulsion system and process for an LNG powered ship, and belongs to the technical field of energy recovery and utilization.

Background technique

At present, in the context of controlling carbon emissions in the global shipping market, although heavy oil is still the first choice of fuel for most ships, the proportion of LNG-powered ships is increasing year by year. Relevant research shows that by 2030, non-traditional fuels will account for 9%, and by 2050, there will be a significant increase and a larger share of all ship-type fuels. However, in the development process of LNG-powered ships, the utilization of LNG, a high-grade energy source, is too simple. In most cases, only LNG combustion is used to provide power for ships, and other energy sources are not combined. Systematization and efficiency are carried out according to the characteristics of LNG. use. In addition, although there are some comprehensive energy utilization systems for LNG, most of them are not designed for ships.

At present, the main energy utilization method for LNG pressure difference is power generation. The patent with the application number of 201610063898.6 discloses a natural gas pressure difference energy recovery-preparation LNG system and process. The system is provided with a heat exchange device, an expansion unit, a cold energy recovery unit and a gas-liquid separation device between the high-pressure natural gas trunk line and the low-pressure natural gas branch line through pipeline connections. The high-pressure natural gas enters the expansion unit and drives the expander to work after heat exchange and cooling, and the generator connected to the expander works accordingly. The low temperature and low pressure natural gas and liquefied natural gas come out from the expander. The liquefied natural gas enters the cold energy recovery unit, and the low temperature and low pressure natural gas enters the low pressure natural gas pipeline through heat exchange with the high pressure natural gas. In its patent, the high-pressure natural gas is used to heat the expanded low-temperature and low-pressure natural gas, which reduces the temperature of the high-pressure natural gas at the inlet of the expander and reduces the power generation efficiency.

Similar to it is the patent with the application number 201520364530.4, which discloses a high-efficiency utilization system for the recovery of natural gas pressure energy and cold energy in the pipeline network. Cold energy recovery to make ice. Although this patent utilizes the pressure difference energy and cold energy of natural gas, the brine cannot be recycled in the cold storage process, and a large amount of fresh water needs to be consumed. Since the freezing point of brine is lower than 0°C, the low-temperature natural gas from the brine pool entering the storage pool may cause the storage pool to freeze and cause equipment damage. And because the urban natural gas pipeline network flow changes with the urban gas consumption, the system is not stable.

SUMMARY OF THE INVENTION

The purpose of the patent of the present invention is to provide a dual power supply and propulsion system for an LNG powered ship in view of the above-mentioned defects and problems of the prior art.

The invention utilizes the high temperature and high pressure natural gas formed by heat exchange with propane and ship main engine cylinder liner cooling water after pressurization to expand and depressurize in the turbine to do work, and drive the generator to generate electricity to provide power for the ship sailing. The natural gas after working in the turbine enters the main engine of the ship and burns to provide power for the ship's navigation. According to the needs of navigation, LNG-powered ships can freely choose to be propelled by the main engine of the ship or electric propulsion. In addition, the thermal energy in the seawater is used to heat the propane after heat exchange with the LNG. It reduces the energy consumption of the ship's propulsion system and improves the economy and environmental protection of the overall operation of the ship.

To achieve the above object, the present invention adopts the following technical solutions:

An LNG powered ship dual power supply and propulsion system and working method, comprising an LNG power supply subsystem and an electric power supply subsystem, wherein the LNG power supply subsystem consists of an LNG liquid storage tank 1, a booster pump 3, an LNG power supply subsystem The inlet a and outlet c of the vaporizer 5, the inlet g and outlet h of the first heat exchanger 6, the inlet k and outlet l of the turbine 7, and the fuel inlet m of the main engine 9 of the ship are connected by pipelines in sequence; the outlet d of the LNG vaporizer 5 , f also use pipelines to connect the inlet v of the propane liquid storage tank 16, the outlet u, the inlet t and outlet s of the second heat exchanger 14, the inlet b and e of the LNG vaporizer 5; the inlet of the first heat exchanger 6 i is also connected to the outlet o of the cooling water cylinder liner 10 of the main engine of the ship through a pipeline, and the outlet j is also connected to the inlet p of the cooling water cylinder liner (10) of the main engine of the ship through a pipeline; the electric power supply subsystem is connected by the power output end x of the turbine 7 , the generator 18, the battery 19, the input end w, the output end z of the power conversion device 20, and the propeller 21 are connected in sequence;

Further, a first solenoid valve 2 is also connected with a pipeline between the liquid storage tank 1 and the booster pump 3 , and a pressure gauge 4 is also connected with a pipeline between the booster pump 3 and the LNG vaporizer 5 .

Further, a second solenoid valve 17 is also connected with a pipeline between the inlets b and e of the LNG vaporizer 5 and the outlet s of the second heat exchanger 14 ; the propane liquid storage tank 16 and the inlet of the second heat exchanger 14 A third solenoid valve 15 is also connected with a pipeline between t.

Further, the inlet r of the second heat exchanger 14 is also connected with a flow meter 13 , a pump 12 , and a fourth solenoid valve 11 in sequence through pipes; seawater is used as the heating medium in the second heat exchanger 14 .

Further, the LNG vaporizer 5 is a three-channel vaporizer, the inlet a and the outlet c are the inlet and outlet of the first channel, the inlet b and the outlet d are the inlet and outlet of the second channel, the inlet e and the outlet f are the inlet and outlet of the third channel, the first The channel is a cold fluid LNG channel. The inlets b and e of the second and third channels are connected by a manifold, and the outlets d and f are connected by a manifold and then connected to the main pipeline as a hot fluid propane channel.

Further, a fifth solenoid valve 8 is connected to the inlet of the first heat exchanger 6 and the outlet o of the ship's main engine cooling water cylinder liner 10 through a pipeline; the heating medium in the first heat exchanger 6 is the ship's main engine cylinder liner cooling water.

A working method of a dual power supply and propulsion system for an LNG powered ship of the present invention includes the following two subsystems: an LNG power supply subsystem and an electric power supply subsystem;

The working mode of the LNG power supply subsystem: LNG at -160°C in the LNG storage tank 1 enters the booster pump 3 through the first solenoid valve 2 and becomes high-pressure LNG after being pressurized, and enters through the inlet a of the high-efficiency and compact LNG vaporizer 5 The high-efficiency and compact LNG vaporizer 5 fully exchanges heat with propane, and the temperature rises to close to 0°C, and then enters the first heat exchanger 6 to exchange heat with the ship's main engine cylinder liner cooling water at about 80°C in the ship's main engine cooling water cylinder liner 10. , becomes high temperature and high pressure natural gas, and then enters the turbine 7 and then expands and does work, the pressure and temperature are reduced, and then enters the main engine 9 of the ship through the outlet 1 of the turbine 7 and burns into the kinetic energy of the ship. At the same time, the propane after heat exchange with LNG enters the propane liquid storage tank 16 from the outlets d and f of the LNG vaporizer 5, and then the propane enters the second heat exchanger 14 from the propane liquid storage tank 16 and enters the LNG after heat exchange with seawater and temperature. Vaporizer 5; Seawater is pumped into the second heat exchanger 14 by the pump 12 through the inlet r of the second heat exchanger 14, and is discharged into the sea through the outlet q of the second heat exchanger 14 after exchanging heat with propane;

The working mode of the electric power supply subsystem: the high temperature and high pressure natural gas entering the turbine 7 expands to do work, and drives the generator 18 to work and generate electricity, and the generated electric energy is stored in the battery 19. The device 20 is assigned to the propeller 21 to make it work according to the sailing demand.

Description of drawings

FIG. 1 is a schematic diagram of the principle of an embodiment of the present invention.

In the picture: 1. LNG storage tank, 2. First solenoid valve, 3. Booster pump, 4. Pressure gauge, 5. LNG vaporizer, 6. First heat exchanger, 7. Turbine, 8. Fifth Solenoid valve, 9. Marine main engine, 10. Marine main engine cooling water cylinder liner, 11. Fourth solenoid valve, 12. Pump, 13. Flow meter, 14. Second heat exchanger, 15. Third solenoid valve, 16. Propane tank, 17. Second solenoid valve, 18. Generator, 19. Battery, 20. Power conversion device, 21. Propeller.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention.

As shown in FIG. 1 : a dual power supply and propulsion system for an LNG powered ship of the present invention, including an LNG power supply subsystem and an electric power supply subsystem, wherein the LNG power supply subsystem consists of an LNG storage tank 1 , booster pump 3, inlet a, outlet c of LNG vaporizer 5, inlet g and outlet h of first heat exchanger 6, inlet k and outlet l of turbine 7, and fuel inlet m of main engine 9 are connected by pipelines in sequence; The outlets d and f of the LNG vaporizer 5 are also connected to the inlet v and outlet u of the propane liquid storage tank 16, the inlet t and outlet s of the second heat exchanger 14, and the inlets b and e of the LNG vaporizer 5 in sequence; the The inlet i of the first heat exchanger 6 is connected to the outlet o of the ship's main engine cooling water cylinder liner 10 through a pipeline, and the outlet j is connected to the inlet p of the ship's main engine cooling water cylinder liner (10) through a pipeline; 7. The power output terminal x, the generator 18, the battery 19, the input terminal w, the output terminal z of the power conversion device 20, and the propeller 21 are connected in sequence; the input terminal y of the power conversion device 20 is also connected with the power output terminal n of the main engine 9 of the ship .

A first solenoid valve 2 is also connected with a pipeline between the liquid storage tank 1 and the booster pump 3 , and a pressure gauge 4 is also connected with a pipeline between the booster pump 3 and the LNG vaporizer 5 .

A second solenoid valve 17 is also connected with a pipeline between the inlets b and e of the LNG vaporizer 5 and the outlet s of the second heat exchanger 14; A third solenoid valve 15 is also connected by pipeline.

The inlet r of the second heat exchanger 14 is also connected with a flow meter 13, a pump 12, and a fourth solenoid valve 11 in sequence through a pipeline; the heating medium in the second heat exchanger 14 is seawater.

The LNG vaporizer 5 is a three-channel vaporizer, the inlet a and the outlet c are the inlet and outlet of the first channel, the inlet b and the outlet d are the inlet and outlet of the second channel, the inlet e and the outlet f are the inlet and outlet of the third channel, and the first channel is In the cold fluid LNG channel, the inlets b and e of the second and third channels are connected by a header pipe, and the outlets d and f are connected by a header pipe and then connected to the main pipeline as a hot fluid propane channel.

The inlet of the first heat exchanger 6 and the outlet o of the ship's main engine cooling water cylinder liner 10 are also connected with a fifth solenoid valve 8 by a pipeline; the heating medium in the first heat exchanger 6 is the ship's main engine cylinder liner cooling water.

A working method of a dual power supply and propulsion system for an LNG powered ship, specifically including the following two methods:

(1) Working mode of the LNG power supply subsystem: LNG at -160°C in the LNG storage tank 1 enters the booster pump 3 through the first solenoid valve 2 and is pressurized into high-pressure LNG, and passes through the efficient and compact LNG vaporizer. 5. The inlet a enters the high-efficiency and compact LNG vaporizer 5, fully exchanges heat with propane, heats up to nearly 0 °C, and then enters the first heat exchanger 6 and the ship's main engine cylinder liner cooling at about 80 °C in the ship's main engine cylinder cooling water jacket 10 The water heats up and turns into high-temperature and high-pressure natural gas. After entering the turbine 7, the pressure and temperature are reduced after the expansion and work are performed. Then, it enters the ship's main engine 9 through the outlet 1 of the turbine 7 and is burned into the kinetic energy of the ship. The waste heat of combustion is cooled by the ship's water tank. The vessel liner cooling water absorption within the jacket 10. At the same time, the propane liquid after heat exchange with LNG enters the propane liquid storage tank 16 from the outlets d and f of the LNG vaporizer 5, and then the propane enters the second heat exchanger 14 from the propane liquid storage tank 16 and exchanges heat with seawater. Enter the LNG vaporizer 5; seawater is pumped into the second heat exchanger 14 by the pump 12 through the inlet r of the second heat exchanger 14, and is discharged into the sea through the outlet q of the second heat exchanger 14 after heat exchange with propane;

(2) The working mode of the electric power supply subsystem: entering the turbine 7 high temperature and high pressure natural gas expands to do work, the rotor in the turbine 7 rotates to drive the generator 18 to work and generate electricity, and the generated electric energy is stored in the battery 19, and the energy in the battery 19 is stored in the battery 19. The electrical energy and the kinetic energy in the ship's main engine 9 are determined by the power conversion device 20 to be distributed to the propeller 21 according to the navigation requirements to make it work.

The above descriptions are merely preferred embodiments of the present invention. Of course, the present invention can also have other various embodiments. Without departing from the spirit and essence of the present invention, any person skilled in the art can make various corresponding equivalent changes and modifications according to the present invention. , all belong to the protection scope of the appended claims of the present invention.

Claims (9)

1. The utility model provides a double dynamical supply of LNG power ship and propulsion system which characterized in that: the LNG power supply system is composed of an LNG power supply subsystem and an electric power supply subsystem; the LNG power supply subsystem is formed by sequentially connecting an LNG liquid storage tank (1), a booster pump (3), an inlet a and an outlet c of an LNG vaporizer (5), an inlet g and an outlet h of a first heat exchanger (6), an inlet k and an outlet l of a turbine (7) and a fuel inlet m of a marine main engine (9) by pipelines; outlets d and f of an LNG vaporizer (5) in the LNG power supply subsystem are communicated by adopting a manifold and are sequentially connected with an inlet v and an outlet u of a propane liquid storage tank (16), an inlet t and an outlet s of a second heat exchanger (14) and manifold inlets of inlets b and e of the LNG vaporizer (5) through pipelines; the inlet i of the first heat exchanger (6) is connected with the outlet o of the cooling water cylinder sleeve (10) of the marine main engine through a pipeline, and the outlet j is also connected with the inlet p of the cooling water cylinder sleeve (10) of the marine main engine through a pipeline; the electric power supply subsystem is formed by sequentially connecting a power output end x of the turbine (7), a generator (18), a storage battery (19), an input end w and an output end z of a power conversion device (20) and a propeller (21); the input end y of the power conversion device (20) is also connected with the power output end n of the marine main engine (9).

2. The LNG-powered ship dual-power supply and propulsion system of claim 1, wherein: and a first electromagnetic valve (2) is connected between the LNG liquid storage tank (1) and the booster pump (3) through a pipeline.

3. The LNG-powered ship dual-power supply and propulsion system of claim 1, wherein: and a pressure gauge (4) is connected between the booster pump (3) and the LNG vaporizer (5) through a pipeline.

4. The LNG-powered ship dual-power supply and propulsion system of claim 1, wherein: and a second electromagnetic valve (17) is connected between the inlets b and e of the LNG vaporizer (5) and the outlet s of the second heat exchanger (14) by adopting pipelines.

5. The LNG-powered ship dual-power supply and propulsion system of claim 1, wherein: and a third electromagnetic valve (15) is connected between the propane liquid storage tank (16) and the inlet t of the second heat exchanger (14) by adopting a pipeline.

6. The LNG-powered ship dual-power supply and propulsion system of claim 1, wherein: the inlet r of the second heat exchanger (14) is also sequentially connected with a flowmeter (13), a pump (12) and a fourth electromagnetic valve (11) by pipelines; wherein the heating medium in the second heat exchanger (14) adopts seawater.

7. The LNG-powered ship dual-power supply and propulsion system of claim 1, wherein: the LNG vaporizer (5) is a three-channel vaporizer, wherein an inlet a and an outlet c are inlets and outlets of a first channel, an inlet b and an outlet d are inlets and outlets of a second channel, an inlet e and an outlet f are inlets and outlets of a third channel, the first channel is a cold fluid LNG channel, the inlets b and e of the second channel and the three channels are connected by adopting manifolds, and the outlets d and f are connected with a main pipeline after being connected by adopting manifolds to be used as hot fluid propane channels.

8. The LNG-powered ship dual-power supply and propulsion system of claim 1, wherein: the inlet of the first heat exchanger (6) and the outlet o of the cooling water cylinder sleeve (10) of the marine main engine are also connected with a fifth electromagnetic valve (8) by adopting a pipeline; wherein the heating medium in the first heat exchanger (6) adopts cooling water of a main engine cylinder jacket of the ship.

9. A working method of a double-power supply and propulsion system of an LNG power ship is characterized in that: the method comprises the following two working modes:

(A) the working mode of the LNG power supply subsystem is as follows: LNG in the LNG liquid storage tank (1) enters a booster pump (3) through a first electromagnetic valve (2) and is changed into low-temperature high-pressure LNG through pressurization, then enters an LNG vaporizer (5) to be fully exchanged with propane to be changed into high-pressure natural gas close to 0 ℃, then enters a first heat exchanger (6) to be exchanged with cooling water of a ship main engine cylinder sleeve in a ship main engine cooling water cylinder sleeve (10) to be exchanged with heat and heated to be changed into high-temperature high-pressure natural gas, then enters a turbine (7) to be expanded and acted to be changed into low-temperature low-pressure natural gas, and then enters a ship main engine (9) to be combusted into; meanwhile, propane after heat exchange with LNG enters a propane liquid storage tank (16) from the LNG vaporizer (5), and then enters a second heat exchanger (14) from the propane liquid storage tank (16) to be heated and then enters the LNG vaporizer (5); seawater is pumped into a second heat exchanger (14) by a pump (12), exchanges heat with propane and is discharged into the sea;

(B) the working mode of the electric power supply subsystem is as follows: the high-temperature and high-pressure natural gas enters the turbine (7) to do work through expansion, the generator (18) is driven to work, the generated electric energy is stored in the storage battery (19), and the electric energy in the storage battery (19) and the kinetic energy in the ship main engine (9) are distributed to the propeller (21) to work through the power conversion device (20) according to the navigation requirement.

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