CN104595063A - Liquefied natural gas gasification system based on cooling water residual heat of dual-fuel ship engine - Google Patents

Abstract

The invention discloses a liquefied natural gas gasification system based on the waste heat of the cooling water of a dual-fuel marine engine, which is composed of four subsystems: a cylinder liner cooling water circulation system, a working medium circulation system, an LNG supply gasification system and a PLC control system; the cylinder liner cooling The water circulation system includes cylinder jacket water pump, cooling water tank, LNG/diesel dual-fuel engine, plate heat exchanger and fan radiator; The working medium inlet of the heater, the LNG supply gasification system includes LNG pump, LNG vaporizer and auxiliary LNG storage tank. The auxiliary LNG storage tank is regulated by manual regulating valve, LNG pump, third liquid flow sensor and third liquid ratio The valve is connected with the LNG gasifier; the invention utilizes the waste heat of the cylinder jacket water of the LNG/diesel dual-fuel engine to vaporize the LNG, cools and dissipates heat from the high-temperature cylinder jacket water, and improves the fuel combustion of the LNG/diesel dual-fuel engine at the same time efficiency.

Description

LNG gasification system based on waste heat of dual-fuel marine engine cooling water

technical field

The invention relates to the technical field of waste heat gasification LNG (Liquefied Natural Gas, liquefied natural gas) equipment, in particular to an LNG gasification system for waste heat of cooling water of LNG/diesel dual-fuel ship engine.

Background technique

Compared with traditional diesel engines, LNG/diesel dual-fuel engines have the advantages of less harmful emissions and can meet increasingly stringent emission regulations. Heavy-duty trucks, etc. However, liquid LNG at a temperature of -162°C needs to be vaporized into a gaseous state before it can be used as engine fuel, and every kilogram of LNG needs to absorb 837kJ of heat for gasification. At the same time, the effective thermal efficiency of the traditional engine is less than 50%, the remaining 25% of the heat is taken away by the exhaust gas, the other 20% of the heat is taken away by the cylinder liner cooling water, and the remaining 5% is dissipated to the atmosphere through heat radiation and lubricating oil .

Publication number CN103899440A (published on July 02, 2014) discloses a marine gas/dual fuel engine LNG gasification system and control method based on exhaust energy recovery, including heat exchange medium tank, exhaust heat exchanger, heat dissipation The heat exchange medium in the heat exchange medium tank enters the exhaust heat exchanger through the first adjustable flow pump, enters the LNG vaporizer after passing through the radiator, and then flows back In the heat exchange medium tank, the external water source enters the engine expansion water tank and the radiator respectively through the liquid collecting tray and the three-way valve, and then is discharged. The external water source entering the radiator does not mix with the heat exchange medium, that is, flows according to their corresponding pipelines. This technology recovers exhaust waste heat from dual-fuel engines and uses it for LNG gasification, but does not involve the recovery of waste heat from cylinder liner cooling water.

The document of Chinese Patent Publication No. CN103967648A (publication date: August 6, 2014) provides a comprehensive waste heat recovery system for marine low-speed diesel engines, including a combined waste heat boiler system, a power turbine power generation system, a steam turbine power generation system, and a high-temperature cooling water utilization system Thermal equipment and organic working medium steam turbine power generation system, in which the jacket water organic working medium preheater connected in parallel with the jacket water heat exchanger, when working, the organic working medium enters the medium temperature after passing through the jacket water organic working medium preheater The heat exchanger then enters the organic working medium evaporator section, and the high-pressure organic working medium drives the steam turbine power generation system to generate electricity, and the waste heat of the jacket water of the diesel engine is used to generate electricity. There is no LNG/diesel dual-fuel engine and LNG gasification technology. At present, there is no technical report on recovering the waste heat of cooling water and using it for gasification of LNG.

Contents of the invention

The technical problem solved by the invention is to provide a liquid natural gas gasification system based on liquid natural gas/diesel dual-fuel ship engine cooling water waste heat, which can recover the cooling water waste heat and use it for gasifying LNG.

The technical solution adopted in the present invention is: it is composed of four subsystems, namely cylinder liner cooling water circulation system, working medium circulation system, LNG supply gasification system and PLC control system. The cylinder liner cooling water circulation system includes cylinder liner water pump, cooling water tank, LNG/ Diesel dual-fuel engine, plate heat exchanger and fan radiator, the connecting pipe between the jacket water outlet of the LNG/diesel dual-fuel engine and the jacket water inlet on the upper part of the cooling water tank is sequentially connected with the first temperature sensor , the first three-way valve, the first liquid flow sensor and the first liquid proportional regulating valve, the middle port of the first three-way valve is connected with the small circulation of the engine cooling system; the cylinder jacket water outlet at the bottom of the cooling water tank is connected with the first, The middle port of the first three-way between the second liquid solenoid valves is connected, and the jacket water pump is connected between the jacket water outlet at the bottom of the cooling water tank and the middle port of the first three-way; the first three-way The upper port of the plate heat exchanger is connected with the plate heat exchanger, and the lower port of the first tee is connected with the water inlet of the fan radiator; the water outlet of the plate heat exchanger is connected with the left port of the second tee. The third liquid solenoid valve is connected between the water outlet of the device and the left port of the second three-way, the right port of the second three-way is connected with the water outlet of the fan radiator, and the right port of the second three-way is connected with the water outlet of the fan radiator. The fourth liquid solenoid valve is connected between the water outlets of the fan radiator; the middle port of the second three-way passes through the liquid check valve, the second three-way valve, the second temperature sensor and the cylinder liner of the LNG/diesel dual-fuel engine. The water inlet is connected, and the middle port of the second three-way valve is connected with the small circulation of the engine cooling system; the first and second temperature sensors, the first liquid proportional regulating valve, the first liquid flow sensor, the cylinder jacket water pump, the first 1. The second, third, and fourth liquid check valves are all connected to the PLC controller in the PLC control system; the working medium circulation system includes a working medium tank and a working medium pump, and the working medium tank is connected to the plate heat exchanger through the working medium outlet The inlet of the working fluid, the second liquid proportional regulating valve, the second liquid flow sensor, the working fluid pump, and the third temperature sensor are sequentially connected between the working fluid tank and the plate heat exchanger; the working fluid outlet of the plate heat exchanger is connected to the The working fluid inlet connection of the LNG gasifier, the working fluid outlet of the LNG gasifier is connected to the working fluid inlet of the working fluid box; the LNG supply gasification system includes the LNG pump, the LNG gasifier and the auxiliary LNG storage tank, and the auxiliary LNG storage tank The tank is connected to the LNG vaporizer through the manual regulating valve, the LNG pump, the third liquid flow sensor, and the third liquid proportional regulating valve in sequence. The flow sensor, the third liquid proportional regulating valve and the LNG pump are respectively connected to the PLC controller; when the water outlet temperature of the cylinder liner is between 75°C and 90°C, the PLC controller controls the closing of the second and third liquid solenoid valves, and the closing of the third liquid solenoid valve. 1. The fourth liquid solenoid valve is opened, and the jacket water pump transports the high-temperature jacket water to the fan radiator to dissipate heat. The cooled jacket cooling water flows back to the cylinder of the LNG/diesel dual-fuel engine through the liquid check valve. The jacket absorbs heat. When the water outlet temperature of the cylinder jacket is greater than or equal to 90°C, the PLC controller controls the liquid The second and third body solenoid valves are opened, the first and fourth liquid solenoid valves are closed, and the jacket water pump transports the high-temperature jacket cooling water from the outlet of the jacket to the plate heat exchanger to release heat to the working medium. The temperature of the cooling water drops, and it returns to the cylinder liner to absorb heat through the liquid check valve; the PLC controller gives instructions to the working medium pump to pump the working medium out of the working medium tank, and after absorbing heat from the plate heat exchanger, it is delivered to the LNG gas. Heat is released in the carburetor, and then flows to the plate heat exchanger to absorb heat again.

The beneficial effects of the present invention are:

1. The present invention provides a set of auxiliary LNG gasification system, which utilizes the waste heat of the cylinder jacket water of the LNG/diesel dual-fuel engine to gasify LNG, so as to cool and dissipate heat from the high-temperature cylinder jacket water, and at the same time improve the LNG/diesel fuel efficiency. Combustion efficiency of dual fuel engine fuel.

2. The present invention adopts a PLC controller to automatically control the system, which can ensure the precise delivery of working fluid, natural gas and jacket water and ensure the safety of operators.

3. The present invention adopts the mutual cooperation of temperature sensor, flow sensor, liquid proportional regulating valve and PLC control system in the process of engine cold start, replaces the traditional engine thermostat, and accurately controls the temperature of the cooling water entering the engine cylinder liner. Control, so as to ensure that the cooling water that finally enters the cylinder liner of the LNG/diesel dual fuel engine maintains the optimum cooling temperature of the engine liner.

The present invention will be described in more detail below in conjunction with the accompanying drawings and specific embodiments.

Description of drawings

Fig. 1 is the structure schematic diagram of the liquefied natural gas gasification system based on the waste heat of the cooling water of the dual-fuel marine engine of the present invention;

In the figure: 1. Gas solenoid valve; 2. Natural gas regulator tank; 3. Pressure sensor; 4. Manual control valve; 5. Gas proportional control valve; 6. Gas filter; 7. Natural gas/air mixer; 8. Engine cylinder; 9. PLC controller; 10. Different diameter tee; 11. Gas one-way valve; 12. LNG vaporizer; 13. Liquid proportional regulating valve; 14. Liquid flow sensor; 15. Three-way valve ; 16. Temperature sensor; 17. Three-way valve; 18. Liquid one-way valve; 19. Cooling water tank; 20. LNG/diesel dual fuel engine; 21. Plate heat exchanger; 22. High temperature cylinder jacket pump; 23. Work 24. Working medium tank; 25. Liquid proportional regulating valve; 26. Temperature sensor; 27. Temperature sensor; 28. Temperature sensor; 29. Flow sensor; 30. Working medium pump; 31. Liquid flow sensor; 32. Liquid proportional regulating valve; 33, 34, 35, 36. Liquid solenoid valve; 37. Adjustable speed motor; 38. Fan radiator; 39. LNG pump; 40. Manual regulating valve; 41. Natural gas leakage alarm ;42. Auxiliary LNG storage tank; 43. LNG liquid level sensor; 44. Gas check valve; 45. Flash steam (Boil Off Gas, referred to as BOG, flash steam) storage tank; 46. Gas pressure sensor; 47. Temperature sensor ; 48. Temperature sensor.

Detailed ways

As shown in Fig. 1, the present invention is composed of four subsystems, which are cylinder jacket cooling water circulation system, working medium circulation system, LNG supply gasification system and PLC control system.

The liner cooling water circulation system includes a high-temperature liner water pump 22, a cooling water tank 19, an LNG/diesel dual-fuel engine 20, a plate heat exchanger 21, a fan radiator 38, and connecting pipes. The jacket water outlet on the left side of the LNG/diesel dual-fuel engine 20 is connected to the jacket water inlet on the top of the cooling water tank 19 through a pipeline, and the jacket water outlet of the LNG/diesel dual-fuel engine 20 and the cooling water tank 19 A temperature sensor 16, a three-way valve 15, a liquid flow sensor 14, and a liquid proportional regulating valve 13 are sequentially connected to the connecting pipes between the upper cylinder jacket water inlets. Wherein, the middle port of the three-way valve 15 is connected with the small circulation of the engine cooling system through a pipeline. The jacket water outlet at the bottom of the cooling water tank 19 is connected to the middle port of the tee between the liquid solenoid valve 33 and the liquid solenoid valve 34 through a pipeline, and the jacket water outlet at the bottom of the cooling water tank 19 is connected to the middle port of the tee. A high-temperature jacket water pump 22 is connected to the connecting pipeline between the ports. The upper port of the tee between the liquid solenoid valve 33 and the liquid solenoid valve 34 is connected to the high-temperature jacket water inlet on the upper left side of the plate heat exchanger 21, and the upper port of the tee is connected to the left side of the plate heat exchanger 21. The connection pipe between the high-temperature cylinder jacket water inlets on the upper side is connected to the liquid solenoid valve 34, the lower port of the tee is connected to the water inlet on the left side of the fan radiator 38, and the lower port of the tee is connected to the fan radiator. The pipeline between the water inlets on the left side of radiator 38 is connected with liquid electromagnetic valve 33. The high-temperature jacket water outlet on the lower right side of the plate heat exchanger 21 is connected to the left port of the tee 29 through a pipe, and between the high-temperature jacket water outlet on the lower right side of the plate heat exchanger 21 and the left port of the tee 29 A liquid solenoid valve 35 is connected to the pipeline between the three links. A liquid electromagnetic valve 36 is connected on the pipeline between the water outlets. Wherein, the fan radiator 38 is connected with the adjustable speed motor 37, and is driven by the adjustable speed motor 37; the middle port of the tee 29 is connected with the cylinder jacket water inlet on the right side of the LNG/diesel dual fuel engine 20 through a pipeline , a liquid check valve 18, a three-way valve 17, and a temperature sensor 27 are sequentially connected to the connecting pipe between the middle port of the tee 29 and the jacket water inlet on the right side of the LNG/diesel dual-fuel engine 20, wherein, The middle port of the three-way valve 17 is connected with the small circulation of the engine cooling system by a pipeline. In the cylinder liner cooling water circulation system, the temperature sensors 16, 27, and the liquid flow sensor 14 are all connected to the analog input module through signal lines, and then connected to the PLC controller 9; the PLC controller 9 is connected to the amplifier through the control line, and then respectively connected to the The speed-adjustable motor 37 on the liquid proportional regulating valve 13, the high-temperature cylinder jacket water pump 22, the liquid check valves 33, 34, 35, 36 and the fan radiator 38.

The working medium circulation system includes a working medium tank 24, a working medium pump 30, connecting pipelines and the like. Wherein, the lower left side of the working medium box 24 is the working medium outlet, and the working medium box 24 is connected to the working medium inlet on the upper right side of the plate heat exchanger 21 through the working medium outlet and the pipeline, and between the working medium box 24 and the plate heat exchanger 21 The connecting pipelines are connected with a liquid proportional regulating valve 32 , a liquid flow sensor 31 , a working medium pump 30 and a temperature sensor 28 in sequence. The working medium outlet on the left lower part of the plate heat exchanger 21 is connected with the working medium inlet on the lower side of the LNG vaporizer 12 through a pipeline, and the working medium outlet on the left lower part of the plate heat exchanger 21 is connected to the LNG vaporizer 12 A temperature sensor 26 is connected to the connecting pipe between the working fluid inlets at the side of the lower section. The working medium outlet on the upper left side of the LNG gasifier 12 is connected with the working medium inlet on the upper right side of the working medium box 24 through a pipeline, and the working medium outlet on the upper left side of the LNG gasifier 12 is connected to the upper right side of the working medium box 24. A temperature sensor 47 is connected to the connecting pipe between the sides, and the temperature sensor 47 is as close as possible to the working medium outlet end on the upper left side of the LNG vaporizer 12 . A working fluid level sensor 23 is connected to the upper part of the working fluid tank 24 . In the working fluid circulation system, the liquid flow sensor 31, the temperature sensors 28, 26, 47, and the working fluid level sensor 23 are all connected to the analog input module through signal lines, and then connected to the PLC controller 9; the PLC controller 9 controls the The line is connected to the amplifier, and then connected to the liquid proportional regulating valve 32 and the working medium pump 30 respectively.

The LNG supply gasification system includes LNG pump 39, LNG vaporizer 12, auxiliary LNG storage tank 42, flash steam storage tank 45, reducing tee 10, natural gas regulator tank 2, gas filter 6, natural gas/air Mixer 7, engine cylinder 8 and connecting pipes, etc. Wherein, the auxiliary LNG storage tank 42 is connected with the LNG inlet at the bottom end of the LNG vaporizer 12 through a pipeline, and the connecting pipeline between the auxiliary LNG storage tank 42 and the LNG inlet at the bottom end of the LNG vaporizer 12 is sequentially connected with a manual adjustment Valve 40, LNG pump 39, liquid flow sensor 29, liquid proportional regulating valve 25. The gaseous natural gas outlet at the top of the LNG vaporizer 12 is connected with the gaseous natural gas inlet at the bottom of the natural gas regulator tank 2 through a pipeline, and the gaseous natural gas outlet at the top of the LNG gasifier 12 is connected with the gaseous natural gas at the bottom of the natural gas regulator tank 2 A temperature sensor 48, a gas one-way valve 11, and a tee with different diameters 10 are sequentially connected to the connecting pipeline between the inlets. Among them, the middle port of the reducing tee 10 and the upper port of the flash steam storage tank 45 are connected by a pipeline, and a gas is installed on the connecting pipe between the middle port of the reducing tee 10 and the upper port of the flash steam storage tank 45. Solenoid valve 1. A pressure sensor 46 is installed on the top of the flash gas storage tank 45 . The upper left side of the auxiliary LNG storage tank 42 is connected to the bottom of the flash gas storage tank 45 through a pipeline, and a gas check valve is installed on the connecting pipeline between the upper left side of the auxiliary LNG storage tank 42 and the bottom of the flash gas storage tank 45 44. The gas filter 6 is connected to the top of the natural gas regulator tank 2 through a pipeline, and the connection pipeline between the gas filter 6 and the top of the natural gas regulator tank 2 is sequentially connected with a manual regulating valve 4 and a gas ratio regulator. Valve 5, wherein a pressure sensor 3 is installed on the top of the natural gas regulator tank 2. The gas filter 6 is connected to the natural gas/air mixer 7 through pipelines, and the natural gas/air mixer 7 is connected to the engine cylinder 8 through pipelines. In the LNG supply gasification system, the liquid flow sensor 29, the temperature sensor 48, the liquid level sensor 43, and the pressure sensor 3 are all connected to the analog input module through the signal line, and then connected to the PLC controller 9; the PLC controller 9 is connected through the control line It is connected to the amplifier, and then respectively connected to the liquid proportional regulating valve 25, the LNG pump 39, the gas solenoid valve 1, and the gas proportional regulating valve 5.

PLC control system includes temperature sensor 16, liquid proportional regulating valve 13, liquid flow sensor 14, temperature sensor 27, liquid proportional regulating valve 32, liquid flow sensor 31, temperature sensor 28, temperature sensor 26, working fluid level sensor 23, LNG Liquid level sensor 43, liquid flow sensor 30, liquid proportional regulating valve 25, gas proportional regulating valve 5, gas solenoid valve 1, gas pressure sensor 46, liquid solenoid valves 33, 34, 35, 36, adjustable speed motor 37, PLC Controller 9, temperature sensor 47, temperature sensor 48 and connection lines etc.

The traditional engine uses a thermostat to automatically adjust the amount of water entering the radiator according to the temperature of the cooling water to ensure that the engine works in a suitable temperature range. The present invention adopts temperature sensor 16 and flow sensor 14, liquid proportional regulating valve 13 and PLC control system to finish to engine cold start process, promptly is realized by LNG/diesel dual-fuel engine 20 and three-way valve 17 and three-way valve 15 other components The small circulation of the cylinder liner cooling water, the temperature sensor 16 detects the water temperature of the water outlet of the cylinder liner, when the water temperature gradually reaches or exceeds 75°C, the small circulation no longer meets the cooling requirements of the engine, and the cooling water will gradually enter The system has a large cycle, because the temperature difference is relatively small at this time, the heat transfer effect is not obvious, and the plate heat exchanger 21 cannot provide enough heat for LNG gasification, so the plate heat exchanger is only used when the water outlet temperature of the cylinder liner reaches 90°C. The heat exchanger 21 performs heat exchange. When the outlet jacket water temperature is between 75°C and 90°C, the system uses the fan radiator 38 to discharge the heat of the medium and high temperature jacket water, and the jacket cooling water returns to the circulation after heat dissipation. In pipeline.

When the water outlet temperature of the cylinder liner is between 75°C and 90°C, the PLC controller 9 controls the liquid solenoid valves 34 and 35 to be in the closed state, and the control liquid solenoid valves 33 and 36 are in the open state. The jacket cooling water pump 22 transports the high-temperature jacket water from the outlet of the jacket to the fan radiator 38 for heat release, and the cooled jacket cooling water flows back to the cylinder jacket of the engine through the liquid check valve 18 to absorb heat. The speed-adjustable motor 37 can adjust the fan speed to adjust the heat dissipation. When the water outlet temperature of the cylinder liner is greater than or equal to 90°C, at this time, the PLC controller 9 controls the liquid solenoid valves 34, 35 to be in the open state, while the liquid solenoid valves 33, 36 are in the closed state, and the liner water pump 22 will turn the high temperature cylinder The jacket cooling water is transported from the water outlet of the cylinder liner to the plate heat exchanger 21 to release heat to the working medium, where heat exchange is performed with the working medium, and the temperature of the cooling water after heat release decreases, and then returns to the cylinder through the liquid check valve 18 The heat is absorbed in the sleeve, and the flow is circulated in this way. It is the cylinder jacket water pump 22 that drives the cylinder jacket cooling water to circulate, and the cooling water tank 19 is used to store excess or replenish insufficient cooling water. The effect of the liquid check valve 18 is to prevent the cooling water in the cooling water small circulation loop from flowing back into the plate heat exchanger 21 or the fan radiator 38, so that the cooling water can only flow in one direction in the large circulation.

After the cooling water flows in the large circulation, the PLC controller 9 instructs the working medium pump 30 to start, pumps the working medium out of the working medium tank 24, and releases heat from the plate heat exchanger 21 to the LNG vaporizer 12 after absorbing heat . After the heat release, the temperature of the working medium decreases, and it flows to the plate heat exchanger 21 again through the pipeline to absorb heat from the cooling water of the cylinder liner, and circulates in this way, and the circulation flow resistance is overcome by the working medium pump 30 . The working fluid box 24 stores surplus or insufficient working fluid. The LNG pump 39 drives the LNG auxiliary LNG storage tank 42 to flow to the LNG gasifier 12, where it absorbs heat from the working medium and gasifies it into natural gas. The natural gas is stored in the natural gas surge tank 2, and the natural gas is filtered by the gas filter 6. The natural gas/air mixer 7 is mixed into a combustible mixture, which is inhaled into the cylinder to burn for work. When the engine cylinder 8 only works with diesel oil, the high-temperature cylinder liner cooling water does not flow through the plate heat exchanger 21, but flows through the fan radiator 38, and the cooled cooling water flows to the engine cylinder liner again, while the working fluid and LNG gas Converter 12 is not involved in the work. Wherein, the function of the liquid flow sensor 31 is to measure the flow rate of the working medium pipeline, the function of the temperature sensor 47 is to detect the temperature value at the outlet of the working medium in the LNG vaporizer 12, and the function of the liquid proportional regulating valve 32 is to control the flow rate of the working medium the size of. A temperature sensor 26 and a temperature sensor 28 are respectively installed at the inlet and outlet of the plate heat exchanger 21 for measuring the temperature values of the inlet and outlet of the plate heat exchanger 21 . A working fluid level sensor 23 is installed above the working medium box 24 for monitoring the liquid level of the working medium in the working medium box 24 .

After the cooling water flows in a large circulation, the LNG pump 39 pumps LNG from the auxiliary LNG storage tank 42 into the LNG vaporizer 12, and absorbs the heat of the working fluid in the LNG vaporizer 12, and vaporizes the LNG into natural gas. The gas is stored in the natural gas pressure-stabilized gas tank 2 through the gas check valve 11, and a gas check valve 11 is provided to prevent natural gas from flowing back. The natural gas stabilized gas tank 2 stores natural gas at a stable pressure for the LNG/diesel dual-fuel engine 20. After the natural gas is filtered by the gas filter 6, it forms a combustible mixture with air in the natural gas/air mixer 7 and is sucked into the engine cylinder 8. Combustion works. In order to detect the LNG flow in real time, a flow sensor 29 is provided, and a temperature sensor 48 detects the air temperature at the gas outlet of the LNG vaporizer 12. The function of the gas ratio regulating valve 5 is to control the flow of natural gas, and the function of the manual regulating valve 40 is to manually adjust the LNG pipeline. The function of manual control valve 4 is to manually adjust the on-off of natural gas in the pipeline. When the system fails, the staff can close the manual control valve 40 and manual control valve 4 in time to prevent dangerous situations. When the PLC controller 9 operates normally, the manual control valve 40 and the manual control valve 4 are normally open, and the opening degree is the largest. A pressure sensor 3 is installed above the natural gas stabilizing gas tank 2, and its function is to measure the gas pressure in the natural gas stabilizing gas tank 2. The auxiliary LNG storage tank 42 is provided with a liquid level sensor 43 whose function is to measure the liquid level of LNG in the auxiliary LNG storage tank 42 . Since the LNG in the auxiliary LNG storage tank 42 will evaporate, this part of the gas is called BOG flash steam, and the BOG flash steam increases the pressure of the meteorological space of the LNG storage tank 42, and this part of the BOG flash steam enters through the gas check valve 44 In the flash steam storage tank 45, the function of the gas check valve 44 is to prevent the flash steam from falling back into the auxiliary LNG storage tank 42, and the flash steam storage tank 45 is connected with the natural gas pressure stabilizing gas tank 2 through the reducing tee 10, so that Let the flash steam go into the natural gas regulator tank 2, and there is a gas solenoid valve 1 between the flash steam storage tank 45 and the different-diameter tee 10, and its function is to control the passage of the flash steam into the natural gas regulator tank 2. In addition, a pressure sensor 46 is arranged above the flash steam storage tank 45 , and its function is to measure the pressure of the natural gas in the flash steam storage tank 45 . In the LNG gasification system, the nozzle flanges at both ends of the flash gas storage tank 45, the nozzle flanges at both ends of the LNG pump 39, and the interface flanges between the auxiliary LNG storage tank 42 and the LNG pump 39 A natural gas leakage alarm is installed at the nozzle flange connection of the gas inlet and outlet of the LNG vaporizer 12, the outlet flange connection of the natural gas pressure regulator tank 2, and the nozzle flanges at both ends of the flash gas storage tank 45. A natural gas leakage alarm 41 is respectively installed at the nozzle flanges at both ends of the LNG pump 39, and a natural gas leakage alarm 41 is also connected at the interface flange between the flash steam storage tank 45 and the LNG pump 39, A natural gas leakage alarm 41 is also respectively installed at the nozzle flange of the gas inlet and outlet of the LNG vaporizer 12. The effect of the alarm is that when the natural gas leaks, the staff can find out in time and take corresponding measures in time.

Claims (6)

1., based on a liquified natural gas gasification system for double fuel engine of boat and ship cooling water heat, supply gasification system and these four sub-System's composition of PLC control system by the jacket-cooling water circulatory system, duplex matter system, LNG, it is characterized in that:

The jacket-cooling water circulatory system comprises cylinder sleeve water pump (22), cooling water tank (19), LNG/ Diesel Dual-Fuel Engine (20), plate type heat exchanger (21) and fan type radiating device (38), connecting tube between the jacket water water outlet of LNG/ Diesel Dual-Fuel Engine (20) and the jacket water water intake on cooling water tank (19) top is connected to the first temperature transducer (16) successively, first three-way valve (15), first liquid flow transducer (14) and first liquid ratio adjusting valve (13), the Centronics port of the first three-way valve (15) connects with engine-cooling system short circle, the jacket water water outlet of cooling water tank (19) bottom connects with the Centronics port of first threeway between first, second liquid electromagnetic valve (33,34), between the jacket water water outlet and the Centronics port of first threeway of cooling water tank (19) bottom, be connected to cylinder sleeve water pump (22), the upper end-hole of first threeway connects with plate type heat exchanger (21), and the lower end mouth of first threeway connects with fan type radiating device (38) water inlet, plate type heat exchanger (21) water outlet is connected with the left port of second threeway (29), the 3rd liquid electromagnetic valve (35) is connected between plate type heat exchanger (21) water outlet and the left port of second threeway (29), the right output port of second threeway (29) connects with the water outlet of fan type radiating device (38), between the right output port and the water outlet of fan type radiating device (38) of second threeway (29), be connected to the 4th liquid electromagnetic valve (36), the Centronics port of second threeway (29) is connected with the jacket water water intake of LNG/ Diesel Dual-Fuel Engine (20) through liquid non-return valve (18), the second three-way valve (17), the second temperature transducer (27), and the Centronics port of the second three-way valve (17) connects with engine-cooling system short circle, first, second temperature transducer described (16,27), first liquid ratio adjusting valve (13), first liquid flow transducer (14), cylinder sleeve water pump (22), first, second, third, fourth liquid non-return valve (33,34,35,36) all connect the PLC (9) in PLC control system, duplex matter system comprises working medium case (24), working medium pump (30), working medium case (24), by the working medium import of sender property outlet connecting plate type heat exchanger (21), is connected to second liquid ratio adjusting valve (32), second liquid flow transducer (31), working medium pump (30), three-temperature sensor (28) successively between working medium case (24) and plate type heat exchanger (21), the sender property outlet of plate type heat exchanger (21) is connected with the working medium import of LNG vaporizer (12), and the sender property outlet of LNG vaporizer (12) is connected with the working medium import of working medium case (24), LNG supplies gasification system and comprises LNG pump (39), LNG vaporizer (12) and auxiliary LNG storage tank (42), auxiliary LNG storage tank (42) is connected with LNG vaporizer (12) through manual modulation valve (40), LNG pump (39), the 3rd liquid flow sensor (29), the 3rd liquid fraction modulating valve (25) successively, the gaseous natural gas outlet on LNG vaporizer (12) top is connected with rock gas voltage stabilizing gas tank (2) bottom, and the 3rd liquid flow sensor (29), the 3rd liquid fraction modulating valve (25), LNG pump (39) connect PLC (9) respectively,

When cylinder sleeve outlet temperature is between 75 DEG C to 90 DEG C, PLC (9) controls second, 3rd liquid electromagnetic valve (34, 35) close, first, 4th liquid electromagnetic valve (33, 36) open, high temperature jacket water is transported to heat release in fan type radiating device (38) by cylinder sleeve water pump (22), jacket-cooling water after cooling flow back in the cylinder sleeve of LNG/ Diesel Dual-Fuel Engine (20) through liquid non-return valve (18) and absorbs heat, when cylinder sleeve outlet temperature is more than or equal to 90 DEG C, PLC (9) controls liquid second, 3rd body solenoid valve (34, 35) open, first, 4th liquid electromagnetic valve (33, 36) close, high temperature jacket-cooling water is transported to plate type heat exchanger (21) to working medium heat release from cylinder sleeve water outlet by cylinder sleeve water pump (22), cooling water temperature after heat release reduces, again get back in cylinder sleeve through liquid non-return valve (18) and absorb heat, working medium pumps to working medium pump (30) instruction by PLC (9) from working medium case (24), to heat release LNG vaporizer (12) after plate type heat exchanger (21) heat absorption, again flows to plate type heat exchanger (21) and absorb heat after heat release.

2. according to claim 1 based on the liquified natural gas gasification system of double fuel engine of boat and ship cooling water heat, it is characterized in that: between LNG vaporizer (12) and rock gas voltage stabilizing gas tank (2), be connected to the 4th temperature transducer (48) successively, first cooling gas check valve (11) and reducing tee (10), the Centronics port of reducing tee (10) is connected with the upper port of flash steam storage tank (45), one gas solenoid valve (1) is housed between reducing tee (10) and flash steam storage tank (45), a pressure transducer (46) is equipped with on the top of flash steam storage tank (45), auxiliary LNG storage tank (42) is connected with flash steam storage tank (45), one second cooling gas check valve (44) is housed between auxiliary LNG storage tank (42) and flash steam storage tank (45), 4th temperature transducer (48), first, second cooling gas check valve (11,44), gas solenoid valve (1), pressure transducer (46) connect PLC (9) respectively.

3. according to claim 1 based on the liquified natural gas gasification system of double fuel engine of boat and ship cooling water heat, it is characterized in that: rock gas voltage stabilizing gas tank (2) top is connected with combustion gas filter cleaner (6), connecting tube between combustion gas filter cleaner (6) and rock gas voltage stabilizing gas tank (2) top is connected to successively manual modulation valve (4), gas ratio modulating valve (5), a pressure transducer (3) is equipped with at the top of rock gas voltage stabilizing gas tank (2), combustion gas filter cleaner (6) is connected with rock gas/air mixer (7), rock gas/air mixer (7) is connected with cylinder (8), gas ratio modulating valve (5), pressure transducer (3) connect PLC (9) respectively.

4. according to claim 1 based on the liquified natural gas gasification system of double fuel engine of boat and ship cooling water heat, it is characterized in that: the connecting tube between the sender property outlet of LNG vaporizer (12) and working medium case (24) is connected to one the 5th temperature transducer (47), the 5th temperature transducer (47) is near the sender property outlet end of LNG vaporizer (12).

5. according to claim 1 based on the liquified natural gas gasification system of double fuel engine of boat and ship cooling water heat, it is characterized in that: be connected to a working medium liquid level sensor (23) on the top of working medium case (24), working medium liquid level sensor (23) connects PLC (9) by signaling line.

6. according to claim 1 based on the liquified natural gas gasification system of double fuel engine of boat and ship cooling water heat, it is characterized in that: adjustable speed motor (37) is housed on fan radiator (38), adjustable speed motor (37) connects PLC (9).