CN111765019A

CN111765019A - LPG dual-fuel supply pipeline system

Info

Publication number: CN111765019A
Application number: CN202010462990.6A
Authority: CN
Inventors: 孙瑞; 杨志豪; 蒋光宇; 王登; 孙宇
Original assignee: Yiu Lian Dockyards (shekou) Ltd; China Merchants Heavy Industry Shenzhen Co Ltd
Current assignee: Yiu Lian Dockyards (shekou) Ltd; China Merchants Heavy Industry Shenzhen Co Ltd
Priority date: 2020-05-27
Filing date: 2020-05-27
Publication date: 2020-10-13

Abstract

The invention relates to an LPG dual-fuel supply pipeline system, which comprises a conventional fuel system and an LPG fuel supply system, wherein an original single fuel engine of the conventional fuel system is changed into a dual-fuel engine which is suitable for both conventional fuel and LPG fuel, the fuel supply system is changed into dual-system supply of the conventional fuel and the LPG fuel, the original conventional fuel system is kept unchanged, and the added LPG fuel supply system consists of a storage tank conveying pipeline, a high-pressure boosting unit, a distribution control valve bank, an emergency discharge tank, a safety valve release buffer tank, a double-wall pipe and the like, is used for conveying low-ignition-point petroleum gas, is kept in a liquefied state, is released and vaporized until a nozzle of an engine cylinder, and then is combusted to drive a piston of an engine to do work. The system of the invention enables the engine to use LPG as fuel, reduces cost, has flexible dual-fuel supply switching, and switches offshore to use LPG fuel, meets the national discharge standards of IMO and various ports, and has the advantages of environmental protection, energy saving and convenient operation.

Description

LPG dual-fuel supply pipeline system

Technical Field

The invention relates to the technical field of fuel supply, in particular to an LPG dual-fuel supply pipeline system.

Background

On large transport vessels, the conventional marine fuel supply system is generally used, and consists of a single fuel engine, a fuel tank, an oil inlet pipe, a fuel pump, an oil return pipe, a control valve and a quick-closing valve, and the conventional fuel supply system has the following problems and disadvantages:

1. the fuel consumption is large and the cost is high.

2. The emission is environment-friendly, harmful sulfur oxides, nitrogen oxides, PM2.5 pollutants and CO2 are generated.

3. The uncertainty of the fuel cost is high, and the influence on the ship transportation cost is large.

Therefore, we propose an LPG dual fuel supply line system.

Disclosure of Invention

The invention aims to provide an LPG dual-fuel supply pipeline system, which aims to solve the problems that the traditional steel-sheathed-steel directly-buried heat-insulating pipe conveying mode proposed in the background technology is assisted by a hoisting machine, but the working range of hoisting by the hoisting machine is limited, the working cost of the hoisting machine is high, and the conveying device which is more convenient and fast to convey on the flat ground is required to meet the requirement of actual work.

In order to achieve the purpose, the invention provides the following technical scheme:

an LPG dual-fuel supply pipeline system comprises a conventional fuel system and an LPG fuel supply system, wherein an original single fuel engine of the conventional fuel system is changed into a dual fuel engine which is suitable for both conventional fuel and LPG fuel, the fuel supply system is changed into dual system supply of the conventional fuel and the LPG fuel, the original conventional fuel system is kept unchanged, and the added LPG fuel supply system comprises a storage tank conveying pipeline, a high-pressure boosting unit, a distribution control valve bank, an emergency discharge tank, a safety valve release buffer tank, a double-wall pipe and the like, is used for conveying low-ignition-point petroleum gas, is kept in a liquefied state, is released to be vaporized until a nozzle of an engine cylinder, and then is combusted to drive a piston of the engine to do work.

Preferably, the storage tank delivery line is composed of a storage tank, a low-pressure pump, an outlet control valve, a one-way valve, a safety valve release pipe, a remote-transmission pressure gauge and a delivery line, and the LPG in the storage tank is delivered to the high-pressure pressurization unit.

Preferably, the high-pressure boosting unit is composed of a high-pressure pump, a filter, a safety valve, a one-way valve, a three-way valve, a flow control valve, a remote pressure gauge, a remote thermometer, a heat exchanger, a nitrogen buffer tank, a conveying pipeline, an ethylene glycol pipeline, a nitrogen pipeline, a safety valve release pipe and the like, the LPG conveyed from the storage tank is further boosted and filtered to keep necessary cleanliness, the heat exchanger can adjust the temperature of the LPG to be in a specified range and keep the LPG in a liquid state, and the buffer tank can receive the returned LPG to provide a buffer storage space.

Preferably, the distribution control valve unit is divided into gas supply valve unit and backward flow valves two parts, by long-range pneumatic control valve, pressure control valve, teletransmission manometer, teletransmission thermometer, liquid level switch, the supply pipe, return the liquid pipe, emergent discharge pipe, pneumatic control valve control instrument pipe, the pneumatic control valve box, nitrogen gas blowdown pipe etc. constitute, and control pipeline are carried, in case reveal can promptly discharge, for return the liquid pipe decompression, provide nitrogen gas blowdown for remain LPG in the clearance pipeline.

Preferably, the emergency discharge tank part comprises a discharge tank, a level gauge, a relief valve, a discharge pipe, etc. to give a buffer in case of emergency discharge of the distribution control valve block and to collect liquid that may exist when LPG is vaporized in discharge, avoiding direct discharge to the atmosphere.

Preferably, the safety relief valve buffer tank part comprises a buffer tank, a liquid level meter, a discharge valve, a discharge pipe and the like, and when the safety relief valve is discharged in an emergency, the buffer tank gives a buffer and collects liquid which may exist when LPG is vaporized during discharge, thereby avoiding direct discharge to the atmosphere.

Preferably, the double-wall conveying pipe consists of a double-wall pipe inner pipe, a double-wall pipe outer pipe, a double-wall pipe ventilation pipe, a fan, a pipe clamp and the like, the double-wall pipe inner pipe provides LPG (liquefied petroleum gas) for conveying to the dual-fuel engine, redundant fuel flows back, the outer pipe provides extra protection when the inner pipe leaks, leakage is controlled in the outer pipe, the double-wall pipe ventilation pipe is used for ventilation between the double-wall pipe inner pipe and the outer pipe, vaporized LPG is pumped to an outdoor safety region by the fan when the LPG leaks from the inner pipe to the outer pipe, the pipe clamp is installed between the inner pipe and the outer pipe to provide supporting and damping functions, the double-wall pipe design is mainly adopted for a pipeline between the distribution control valve group and the dual-fuel engine, particularly the pipeline of the part of LPG pipe passes through mechanical places such as a main engine room and the.

Compared with the prior art, the invention has the beneficial effects that: the invention provides a dual-fuel system capable of simultaneously using fuel oil and LPG clean energy, which is particularly suitable for a large-power engine with large fuel oil consumption on a large-scale transport ship, and can realize the following effects:

1. the engine can use LPG as fuel, so that the cost is reduced;

2. the LPG is used as clean energy, so that the sulfur oxide in the emission can be reduced by 100 percent, the nitrogen oxide emission can be reduced by 40 to 85 percent, the PM2.5 pollutant emission can be reduced by 95 to 100 percent, and the CO2 emission can be reduced by 20 percent, so that the pollutant emission of the ship meets the more and more strict standards of the IMO international maritime organization and various port countries;

3. the dual-fuel supply is flexibly switched, the LPG fuel is used after offshore switching, the national emission standard of IMO and various ports is met, the environment is protected, the energy is saved, and the operation is convenient.

Drawings

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

FIG. 2 is an enlarged view of a distribution control valve block in the dual fuel system of the present invention;

FIG. 3 is an enlarged view of the high pressure booster unit in the dual fuel system of the present invention;

FIG. 4 is an enlarged view of a conventional fuel delivery system in the dual fuel system of the present invention;

FIG. 5 is an enlarged view of the tank transfer line in the dual fuel system of the present invention;

FIG. 6 is a side cross-sectional view of a double-walled tube of the present invention;

FIG. 7 is a front view of a double-walled tube of the present invention;

figure 8 is a side view of a double-walled tube of the present invention.

In the figure:

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1-8, the present invention provides a technical solution: an LPG dual-fuel supply pipeline system comprises a conventional fuel system and an LPG fuel supply system, wherein an original single fuel engine of the conventional fuel system is changed into a dual fuel engine which is suitable for both conventional fuel and LPG fuel, the fuel supply system is changed into dual system supply of the conventional fuel and the LPG fuel, the original conventional fuel system is kept unchanged, and the added LPG fuel supply system comprises a storage tank conveying pipeline, a high-pressure boosting unit, a distribution control valve bank, an emergency discharge tank, a safety valve release buffer tank, a double-wall pipe and the like, is used for conveying low-ignition-point petroleum gas, is kept in a liquefied state, is released to be vaporized until a nozzle of an engine cylinder, and then is combusted to drive a piston of the engine to do work.

The storage tank conveying pipeline consists of a storage tank (G1, G2), a low-pressure pump (B1, B2), an outlet control valve V4, a one-way valve V3, a safety valve SV1, a safety valve release pipe P8, a remote pressure gauge S3 and a conveying pipeline P3, and the storage tank conveying pipeline has the function of conveying LPG in the storage tank to a high-pressure pressurization unit, and the working mode of the storage tank conveying pipeline is as follows:

LPG (liquefied petroleum gas) is stored in a storage tank G1 (working pressure is 5bar, temperature is lower than 8 ℃), the LPG is considered as 100% propane component, the saturated vapor pressure of the propane is checked, when the pressure is 5bar, the corresponding temperature is 8 ℃, namely when the pressure in the tank is 5bar, the propane is ensured to be lower than 8 ℃ in the storage tank through related heat insulation means, the LPG is stored in a liquid state, and the LPG is not vaporized;

LPG is pumped from a storage tank G1 by a pump B1 and is conveyed to a high-pressure pressurization unit, the pressure is 29bar, an S3 remote pressure gauge is used for detecting the pressure of the LPG in the pipeline, a safety release valve SV1 is set at 32bar, once a pump outlet pipeline P3 exceeds 32bar, a pressure release valve SV1 is opened, LPG liquid in the LPG is emergently released through a pipeline P8, and the storage tank G1 of the pump B1 and the storage tank G2 of the pump B2 are mutually standby.

The high-pressure boosting unit is composed of high-pressure pumps (B3, B4), filters (S1, S2), safety valves (SV2, SV3, SV4, SV5), check valves (V5, V6, V7, V8), three-way valves (V9, V10), flow control valves (V11, V12), a remote pressure gauge (S11), remote temperature gauges (S4, S5, S10, S12), heat exchangers (J1, J1), a nitrogen buffer tank (G1), delivery lines (P1, P1), a glycol line (P1), a nitrogen line (P1), a relief valve release line (P1), etc., and functions to further boost the pressure of the LPG delivered from the storage tank to 53bar by the high-pressure pumps (B1, B1), and to filter the back-up the V1, the three-way valves (S1, V1, S1, V1, B1) and B1 by mutually switching the three-way valves to the high-pressure pumps, S1;

the hot glycol solution enters a heat exchanger J1 through a pipeline P6 to heat the LPG to 35 ℃ so as to supply the LPG for the engine, the LPG cannot be vaporized at 35 ℃ at the moment, the saturated vapor pressure of the LPG is 12bar, but the pressure of the LPG after the LPG comes out of a pump B1 is more than or equal to 29bar and 12bar, so the LPG keeps a liquid state, and the hot glycol solution is cooled by the LPG to become cold glycol;

after the LPG at 35 ℃ in the pipeline P3 reaches the engine and is supplied with fuel, the residual part returns to the pipeline P4, the temperature of the LPG is increased due to passing through the main engine, the LPG becomes hotter, the LPG reaches the heat exchanger J2, the LPG is subjected to heat exchange with cold ethylene glycol from the pipeline P6 again, the LPG is cooled, the LPG is returned to the inlet of the high-pressure pump (B3, B4) after being cooled, and the LPG is mixed with the LPG from the tanks G1 and G2 and then enters the supply pipeline P3 again.

The buffer tank G4 can receive backflow LPG from a pipeline P4 to provide a buffer storage space, flow control valves V11 and V12 can respectively adjust the flow of the LPG in a pipeline P4 and the buffer tank, a pipeline of nitrogen P7 is connected into the buffer tank G4, the pressure of the nitrogen is 25bar, the volume of the nitrogen is compressible, the gas-liquid ratio can be adjusted along with the quantity of the incoming LPG in the tank G4, so that the buffer function is achieved, a remote pressure gauge S11 provides remote pressure indication, a bar SV5 safety valve is set at 32, the gas is emergently released when the pipeline P4 is in overpressure, and the gas is discharged to a safe area through a pipeline P8;

meters S4, S5, S10, S12 provide remote indication of pressure and temperature at the inlet and outlet of heat exchanger J1, J2, safety valves SV2, SV3 set at 65bar, SV4 set at 32bar, emergency release at overpressure, discharge to the safety region through line P8, check valves (V5, V6, V7, V8) acting to make the fluid move unidirectionally, not reversible.

The distribution control valve group is divided into a gas supply valve group and a return valve group, and consists of a remote pneumatic control valve (V13, V14, V15, V16, V17, V18, V19 and V20), a pressure control valve V22, a remote pressure gauge (S7 and S8), a remote thermometer S7, a liquid level switch S9, a supply pipe P3, a liquid return pipe P4, an emergency discharge pipe P9, a pneumatic control instrument control pipe P10, a pneumatic control valve box G7, a nitrogen purging pipe P11 and the like, and the working mode is as follows:

monitoring a pipeline P4 through a liquid level switch S9, and once the liquid level in the pipeline is abnormal to cause an alarm of a liquid level switch S9, remotely controlling valves V13 and V20 to open emergency discharge through a pipeline P9, if the abnormality cannot be solved, further closing V14 on a liquid return pipe P4, opening V15 and V16 through pipelines P9, closing V18 on a supply pipe P3, opening V17 and opening V19 through a pipeline P9 in emergency discharge through remotely controlling valves V14, V15, V16, V17, V18 and V19;

the pressure control valve V22 is used for reducing the pressure of a liquid return pipe P4 from 53bar to 29bar, the liquid return pipe is ensured to be consistent with the pressure of a high-pressure pump (B3, B4) suction pipe P3 when being converged into the high-pressure pump, and meters S6, S7 and S8 provide remote pressure and temperature transmission indications of the pipelines P3 and P4;

the pneumatic control valve box G7 is used for remotely controlling valves (V13, V14, V15, V16, V17, V18, V19 and V20);

a nitrogen purge line P11 is provided for purging residual LPG from the line if necessary.

The emergency discharge tank part comprises a discharge tank G5, a liquid level meter S13, a discharge valve V21, a discharge pipe P9 and the like, and the emergency discharge tank part works in a mode that when the distribution control valve group discharges emergently, buffering is given, liquid possibly existing when LPG in a P9 pipeline vaporizes during discharge is collected, the liquid is prevented from being directly discharged to the atmosphere, and when the liquid in G5 reaches a certain amount, a liquid level switch S13 is triggered, the liquid can be discharged and collected through a valve V21.

The buffer tank part of the safety release valve comprises a buffer tank G6, a liquid level meter S14, a drain valve V23, a drain pipe P8 and the like, and the working mode is that when the safety release valve is emergently discharged through a P8 pipeline, the buffer valve is used for buffering, liquid possibly existing in LPG evaporation in a P8 pipeline during discharging is collected, direct discharging to the atmosphere is avoided, and when the liquid in G6 reaches a certain amount, a liquid level switch S14 is triggered, the liquid can be drained and collected through the valve V23.

The double-wall pipe P5 comprises a double-wall pipe inner pipe P5-1, a double-wall pipe outer pipe P5-2, a double-wall pipe ventilation pipe (P12, P13), a fan F1, a double-wall pipe clamp P5-3 and the like, and the working mode is as follows:

the double-wall pipe inner pipe P5-1 provides LPG for conveying to the dual-fuel engine, redundant fuel flows back to P4, the outer pipe P5-2 provides extra protection when the inner pipe P5-1 leaks, and leakage is controlled in the outer pipe;

the double-wall pipe ventilation pipes P12 and P13 are used for positive pressure ventilation between the inner pipe and the outer pipe of the double-wall pipe, when LPG leaks from the inner pipe P5-1 to the outer pipe P5-2, vaporized LPG is pumped to an outdoor safety area by a fan F1, P12 is a fan air inlet pipe, and P13 is a fan air outlet pipe;

the pipe clamp P5-3 is arranged between the inner pipe P5-1 and the outer pipe P5-2, and provides supporting and damping effects;

the P3 and P4 pipelines between the distribution control valve group and the dual-fuel engine A2 are mainly designed by adopting a double-wall pipe P5, particularly the LPG pipes P3 and P4 pass through machinery places such as a main engine room, and double-layer protection is carried out by the double-wall pipe design, so that the phenomenon that the LPG leaks to the main engine room to cause that the whole machinery places and even the whole ship are in huge explosion risks is avoided.

The above is only an example to illustrate that a dual fuel system which can use both conventional fuel oil and clean LPG energy is analyzed according to actual conditions of a shipyard, but we can further flexibly expand to different configurations as required as follows:

the storage tank is designed to use 100% propane at present, but Liquefied Petroleum Gas (LPG) added with other media such as butane, isobutane and propylene can also be used, of course, the saturated vapor pressure of the LPG is changed after other components are added, and the design temperature, the design pressure and the safety valve setting of a pipeline are changed to a certain extent in the corresponding system design, which can be adjusted by calculating the corresponding system configuration;

in addition, the size of a storage tank, pump parameters, valves, the size of a buffer tank, the form of a control valve group and the like in the supply pipeline can be adjusted within a certain numerical range according to requirements;

the patent only illustrates a dual-fuel host, a plurality of hosts can be configured actually according to the needs of a ship, a plurality of branch pipes and control valve sets are added on the basis of the design of a supply pipeline of the patent to deliver LPG to the plurality of hosts, which completely depends on the needs of the actual ship.

Although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that various changes in the embodiments and/or modifications of the invention can be made, and equivalents and modifications of some features of the invention can be made without departing from the spirit and scope of the invention.

Claims

1. An LPG dual fuel supply line system, comprising a conventional fuel system and an LPG fuel supply system, characterized in that: the original single fuel engine of the conventional fuel system is changed into a dual fuel engine which is suitable for both conventional fuel and LPG fuel, the fuel supply system is changed into dual system supply of the conventional fuel and the LPG fuel, the original conventional fuel system is kept unchanged, and the newly added LPG fuel supply system comprises a storage tank conveying pipeline, a high-pressure pressurization unit, a distribution control valve bank, an emergency discharge box, a safety valve release buffer tank, a double-wall pipe and the like, and is used for conveying low-ignition-point petroleum gas, keeping the low-ignition-point petroleum gas in a liquefied state until a nozzle of an engine cylinder is released for vaporization, and then burning and driving a piston of the engine to do work.

2. An LPG dual fuel supply line system as set forth in claim 1, wherein: the storage tank conveying pipeline consists of a storage tank, a low-pressure pump, an outlet control valve, a one-way valve, a safety valve release pipe, a remote transmission pressure gauge and a conveying pipeline, and the LPG in the storage tank is conveyed to the high-pressure pressurization unit.

3. An LPG dual fuel supply line system as set forth in claim 1, wherein: the high-pressure boosting unit comprises a high-pressure pump, a filter, a safety valve, a one-way valve, a three-way valve, a flow control valve, a remote pressure gauge, a remote thermometer, a heat exchanger, a nitrogen buffer tank, a conveying pipeline, an ethylene glycol pipeline, a nitrogen pipeline, a safety valve release pipe and the like, the LPG conveyed from the storage tank is further boosted and filtered to keep necessary cleanliness, the heat exchanger can adjust the temperature of the LPG to be in a specified range and keep the LPG in a liquid state, and the buffer tank can receive the backflow LPG to provide a buffer storage space.

4. An LPG dual fuel supply line system as set forth in claim 1, wherein: the distribution control valve group divide into air feed valves and backward flow valves two parts, by long-range pneumatic control valve, pressure control valve, teletransmission manometer, teletransmission thermometer, liquid level switch, the supply line, return the liquid pipe, emergent discharge pipe, pneumatic control valve control instrument pipe, the pneumatic control valve box, nitrogen gas blowdown pipe etc. constitute, and control pipeline are carried, in case reveal can promptly discharge, provide nitrogen gas blowdown for return the liquid pipe decompression for remaining LPG in the clearance pipeline.

5. An LPG dual fuel supply line system as set forth in claim 1, wherein: the emergency discharge tank part comprises a discharge tank, a liquid level meter, a discharge valve, a discharge pipe and the like, and when the distribution control valve group is used for emergency discharge, the emergency discharge tank part gives buffer and collects liquid possibly existing during vaporization of LPG during discharge so as to avoid direct discharge to the atmosphere.

6. An LPG dual fuel supply line system as set forth in claim 1, wherein: the safety release valve buffer tank part comprises a buffer tank, a liquid level meter, a discharge valve, a discharge pipe and the like, and when the safety release valve is in emergency discharge, the buffer tank gives buffer and collects liquid possibly existing in LPG vaporization during discharge so as to avoid direct discharge to the atmosphere.

7. An LPG dual fuel supply line system as set forth in claim 1, wherein: the double-wall conveying pipe is composed of a double-wall pipe inner pipe, a double-wall pipe outer pipe, a double-wall pipe ventilating pipe, a fan, pipe clamps and the like, the double-wall pipe inner pipe provides LPG (liquefied petroleum gas) to be conveyed to the dual-fuel engine, redundant fuel flows back, the outer pipe provides extra protection when the inner pipe leaks, leakage is controlled in the outer pipe, the double-wall pipe ventilating pipe is used for ventilating between the double-wall pipe inner pipe and the outer pipe, vaporized LPG is pumped to an outdoor safe area by the fan when the LPG leaks from the inner pipe to the outer pipe, the pipe clamps are installed between the inner pipe and the outer pipe to provide supporting and damping functions, the double-wall pipe design is mainly adopted for a pipeline between the distribution control valve set and the dual-fuel engine, particularly the double-wall pipe passes through mechanical places such as a main engine room and the like.