A marine methanol fuel supply system and a control method thereof

Abstract

The application discloses a marine methanol fuel supply system, which comprises a methanol daily tank, a coarse filter group, a methanol supply pump, a degassing tank, a methanol circulating pump, a heat exchange unit and a fine filter group which are sequentially connected through a methanol supply pipeline system; the fine filter group is externally connected with a methanol consumption device; the marine methanol fuel supply system further comprises a first control panel and a second control panel; the methanol daily tank is used for storing methanol fuel and is provided with a high liquid level switch and a low liquid level switch which are used for monitoring the liquid level of the methanol fuel in the methanol daily tank; the coarse filter group and / or the fine filter group are redundantly designed and each comprises at least two filter components which are connected in parallel with each other; the filter components are provided with a self-cleaning mechanism which comprises a cleaning brush and a driving mechanism; when a filter component on one side which is in a standby state performs a self-cleaning operation, the cleaning brush starts to rotate under the driving of the driving mechanism, and impurities adhered to the inner surface of the filter screen can be removed.

Description

TECHNICAL FIELD

[0001] The present application relates to a ship fuel supply system, in particular to a methanol fuel supply system for ships and a control method thereof. BACKGROUND

[0002] Green methanol, as a new type of clean energy, has obvious advantages in reducing carbon emissions, reducing air pollution, and improving environmental quality compared to traditional fuels. At the same time, as a liquid product, methanol is available in 125 of the world's largest ports, and methanol can be transported, stored and refueled through standard safety procedures similar to diesel engine operation, with the advantages of mature technology transition, clear regulations, low difficulty and cost of infrastructure reconstruction, and convenient refueling.

[0003] With the smooth convening of the 80th meeting of the IMO Marine Environment Protection Committee (MEPC 80), the International Maritime Organization has further tightened the requirements for international shipping greenhouse gas emission reduction, and has clearly stated that the shipping industry will achieve net zero emissions around 2050. Currently, methanol ship fuel has become an important choice for shipowners, and the order for methanol-powered ships has increased significantly.

[0004] With the maturity of commercial products for methanol engines, domestic methanol fuel supply systems have begun to develop rapidly. However, the existing methanol fuel supply system still has some problems: 1) The methanol fuel supply system generally uses a two-stage heat exchange system to heat treat methanol fuel, which avoids the safety hazards caused by leakage between methanol fuel and heat exchange medium, increasing equipment cost and equipment size; 2) The filter does not have a self-cleaning function, and manual cleaning of the filter screen is required after opening the filter, increasing the risk of fire caused by exposure of methanol fuel; 3) Methanol is discharged to the discharge tank and then pumped back to the methanol storage tank, and when the discharge system needs to be drained, it is difficult to completely drain the methanol residue back to the methanol storage tank, causing unnecessary loss of methanol; 4) There is no air discharge device on the methanol pipeline, which can easily cause internal corrosion of the pipeline; 5) There is a lack of corresponding mechanisms for pump protection. SUMMARY

[0005] The present application aims to overcome at least one of the above-mentioned deficiencies of the prior art, and to provide a methanol fuel supply system for ships to improve the safety of the system and reduce the risk of manual filter cleaning.

[0006] The marine methanol fuel supply system comprises a methanol daily tank, a coarse filter group, a methanol supply pump, a degassing tank, a methanol circulating pump, a heat exchange unit and a fine filter group connected in sequence through a methanol supply pipeline system; the fine filter group is externally connected to a methanol consumption device; the marine methanol fuel supply system further comprises a first control panel and a second control panel; the methanol daily tank is used for storing methanol fuel and is provided with a high liquid level switch and a first low liquid level switch for monitoring the liquid level of the methanol fuel in the methanol daily tank; the methanol supply pump is used for pumping the methanol fuel in the methanol daily tank and finally transmitting the methanol to the externally connected methanol consumption device; the coarse filter group and / or the fine filter group are redundantly designed and each comprises at least two filter members connected in parallel with each other; the filter members are provided with a self-cleaning mechanism comprising a cleaning brush and a driving mechanism arranged at the top of the filter member; the first control panel is used for controlling the fuel filling of the methanol daily tank and the gas pressure in the upper space of the liquid surface in the tank; the second control panel is used for controlling the operating state of the methanol fuel supply system; when the filter member on one side in standby state performs the self-cleaning operation, the cleaning brush starts to rotate under the driving of the driving mechanism; the impurities attached to the inner surface of the filter screen in the filter are dropped off in the process of rotation of the cleaning brush.

[0007] Further, the heat exchange unit is a double-wall plate heat exchanger comprising a first wall plate forming a methanol fuel passage and a second wall plate forming a cold / hot source passage; an air gap is formed between the first wall plate and the second wall plate; when the wall plate on either side of the methanol fuel or the cold / hot source leaks, the liquid on the other side will not be contaminated; the marine methanol fuel supply system further comprises a liquid receiving tray and a waste liquid tank; the liquid receiving tray is arranged at the lower side outside the heat exchange unit and is used for collecting the liquid permeated out of the heat exchange unit when leakage occurs; the waste liquid tank is arranged at the lower end of the liquid receiving tray and is used for receiving the leakage liquid of the heat exchange unit.

[0008] Further, the methanol supply pipeline system comprises a first supply pipeline connecting the outlet of the methanol daily tank and the inlet of the coarse filter group, a second supply pipeline connecting the outlet of the coarse filter group and the inlet of the methanol supply pump, a third supply pipeline connecting the outlet of the methanol supply pump and the inlet of the degassing tank, a first bypass pipeline of the third supply pipeline, a fourth supply pipeline connecting the outlet of the degassing tank and the inlet of the methanol circulating pump, a fifth supply pipeline connecting the outlet of the methanol circulating pump and the inlet of the heat exchange unit, a sixth supply pipeline connecting the outlet of the heat exchange unit and the inlet of the fine filter group, a seventh supply pipeline connecting the outlet of the fine filter group and the inlet of the methanol consumption device; the methanol supply pipeline system further comprises a first return pipeline connecting the first outlet of the methanol supply pump and the methanol daily tank and a second return pipeline connecting the third outlet of the fine filter group and the degassing tank.

[0009] Further, the methanol fuel supply system further comprises a methanol leakage recovery system, which comprises a methanol leakage pump, a U-shaped component, a methanol leakage pipeline, a compressed air pipeline and a second low liquid level switch; the methanol leakage pump is a pneumatic diaphragm pump, which is used to transport the methanol fuel in the methanol leakage recovery system back to the methanol daily cabin; the compressed air pipeline comprises a first hand-operated stop valve and an air filter connected in sequence, which is used to provide power for the methanol leakage pump; the U-shaped component is provided with a second low liquid level switch on one side, and the U-shaped component is arranged at the lowest point of the methanol leakage recovery system, and the methanol fuel in the methanol leakage system can flow into the U-shaped component, and the second low liquid level switch is used to monitor the height of the methanol fuel liquid in the U-shaped component; the methanol leakage pipeline comprises a leakage main pipeline connected with the U-shaped component at one end, a first leakage branch pipeline and a second leakage branch pipeline connected with the leakage main pipeline and the coarse filter group, a third leakage branch pipeline connected with the leakage main pipeline and the methanol supply pump, a fourth leakage branch pipeline connected with the leakage main pipeline and the pipe section where the flow meter is located, a fifth leakage branch pipeline connected with the leakage main pipeline and the first outlet pipeline of the methanol supply pump, a sixth leakage branch pipeline connected with the leakage main pipeline and the methanol circulation pump, a seventh leakage branch pipeline connected with the leakage main pipeline and the second outlet pipeline of the methanol circulation pump, an eighth leakage branch pipeline connected with the leakage main pipeline and the heat exchange unit, a ninth leakage branch pipeline connected with the waste liquid cabin and the liquid receiving disc outside the heat exchange unit, a tenth leakage branch pipeline and an eleventh leakage branch pipeline connected with the leakage main pipeline and the fine filter group, a twelfth leakage branch pipeline connected with the leakage main pipeline and the third outlet pipeline of the fine filter group, a thirteenth leakage branch pipeline connected with the U-shaped component and the methanol leakage pump, a fourteenth leakage branch pipeline connected with the methanol leakage pump and the methanol daily cabin, and a second bypass pipeline connected with the methanol leakage pump of the methanol daily cabin; the first outlet pipeline and the third supply pipeline are the same pipeline; the second outlet pipeline and the fifth supply pipeline are the same pipeline; the third outlet pipeline and the seventh supply pipeline are the same pipeline.

[0010] Further, a plurality of remote control stop valves are arranged on the methanol leakage pipeline, which are used to discharge the methanol fuel in each pipe section of the methanol fuel supply system; the fourth leakage branch pipeline comprises a second hand-operated stop valve and a first check valve connected in sequence, which are used to discharge the pipe section between the third hand-operated stop valve upstream of the flow meter and the fourth hand-operated stop valve downstream;

[0011] The fourteenth leakage branch pipeline comprises a second check valve, a second remote control stop valve and a third check valve connected in sequence; the second remote control stop valve is controlled by the second control panel.

[0012] Further, the methanol fuel supply system further comprises a nitrogen purging pipeline system for purging the methanol fuel supply system of the ship with nitrogen, the nitrogen purging pipeline system comprising pipelines respectively connected between the methanol daily tank, the coarse filter group, the methanol supply pump and the degassing tank; and pipelines connected between the degassing tank, the heat exchange unit, the fine filter group and the methanol discharge main pipeline; and a plurality of remote control isolation valves and a plurality of check valves arranged on the pipelines; the remote control isolation valves are controlled by the first control panel or the second control panel.

[0013] Further, the methanol fuel supply system further comprises a first exhaust pipeline and a second exhaust pipeline, the first exhaust pipeline being used for exhausting the degassing tank, and the second exhaust pipeline being used for exhausting the high point of the methanol circulating pump outlet pipeline; the first exhaust pipeline is provided with a fifth remote control stop valve, one end of the first exhaust pipeline is connected to the discharge main pipeline, and the other end is connected to the nitrogen purging pipeline, and the fifth remote control stop valve is controlled by the second control panel; the second exhaust pipeline comprises a fifth manual stop valve and a sight glass connected in sequence, and the sight glass is used for visually checking whether there is unexhausted gas in the first exhaust pipeline.

[0014] Further, the methanol fuel supply system further comprises a pressure relief system, comprising a first pressure relief pipeline and a second pressure relief pipeline; the first pressure relief pipeline is provided with an automatically opened and closed first safety valve, one end of the first pressure relief pipeline is connected to the top of the degassing tank, and the other end is connected to the methanol daily tank, and the gas and liquid exhausted from the first pressure relief pipeline flow back to the fuel precipitation area of the methanol daily tank; the second pressure relief pipeline is provided with an automatically opened and closed second safety valve, one end of the second pressure relief pipeline is connected to the fifth supply pipeline of the methanol circulating pump, and the other end is connected to the pipeline section between the first safety valve of the first pressure relief pipeline and the methanol daily tank, and the liquid exhausted from the second pressure relief pipeline flows back to the fuel precipitation area of the methanol daily tank through the methanol discharge recovery system.

[0015] The application also provides a control method of the methanol fuel supply system of the ship, comprising a nitrogen purging step, a maintenance step when the methanol is stored in the methanol daily tank, a methanol fuel filling step, a methanol fuel supply step and a methanol discharge recovery step.

[0016] The nitrogen purging step: the first remote control isolation valve on the first supply pipeline and the second remote control stop valve on the seventh supply pipeline are in a closed state, the third remote control stop valve on the second bypass pipeline of the methanol discharge pump is in an open state, nitrogen is used to purge the entire system, after the purging is completed, other remote control stop valves except the third remote control stop valve are closed;

[0017] The maintenance step is: when the methanol is stored in the methanol daily tank, when the first pressure sensor detects that the gas pressure in the upper space of the methanol daily tank reaches the upper limit of the set range, the first pressure regulating valve on the gas venting pipeline is opened to discharge part of the nitrogen gas, and when the gas pressure returns to the set value, the first pressure regulating valve is closed; when the first pressure sensor detects that the gas pressure in the upper space of the methanol daily tank reaches the lower limit of the set range, the second remote control isolation valve on the first nitrogen gas purging pipeline is opened to charge nitrogen gas, and when the gas pressure returns to the set value, the second remote control isolation valve is closed; when the gas pressure in the upper space of the methanol daily tank cannot be restored to the set range, and the pressure / vacuum degree in the upper space of the methanol daily tank reaches the allowed maximum upper limit or lower limit, the pressure / vacuum valve on the gas venting pipeline is automatically opened to discharge part of the nitrogen gas or charge part of the air, so that the pressure and vacuum degree in the upper space of the methanol daily tank are maintained within the threshold range;

[0018] The methanol fuel filling step is: the fourth remote control stop valve on the methanol fuel filling pipeline is opened, and when the height of the methanol liquid surface reaches the position of the high liquid level switch, the fourth remote control stop valve is closed to stop filling; during the filling process, the first pressure regulating valve on the gas venting pipeline is opened to discharge part of the nitrogen gas in the methanol daily tank replaced by the methanol fuel;

[0019] The methanol fuel supply step includes: the sixth remote control stop valve on the seventh supply pipeline is closed; the methanol supply pump injects the methanol fuel into the degassing tank, when the second pressure sensor on the third supply pipeline detects that the pressure of the methanol fuel at the outlet of the methanol supply pump reaches the upper limit of the set range, the second pressure regulating valve on the first methanol return pipeline is opened, and the methanol fuel at the outlet of the methanol supply pump flows into the methanol daily tank for circulation; at the same time, the third pressure sensor on the seventh supply pipeline detects that the pressure of the methanol fuel at the outlet of the methanol circulation pump reaches the upper limit of the set range, the third pressure regulating valve on the second methanol return pipeline is opened, and the methanol fuel at the outlet of the methanol circulation pump flows into the degassing tank for circulation; during the circulation process, the heat exchange unit cools / heats the methanol fuel to make the temperature of the methanol fuel meet the requirements of the external methanol consumption equipment; when the methanol consumption equipment sends a fuel supply command to the second control panel, the second control panel opens the sixth remote control stop valve on the seventh supply pipeline, and the required methanol fuel is delivered to the methanol consumption equipment;

[0020] The methanol leakage recovery step can be used to recover the methanol gas and part of the methanol liquid generated in the methanol fuel supply process, including: the methanol gas directly enters into the methanol daily cabin through the methanol leakage recovery system, part of the methanol liquid enters into the U-shaped component along with the gas flow, the second low liquid level switch detects the methanol liquid and transmits a signal to the second control panel, the second control panel opens the remote control isolation valve on the second nitrogen purge pipeline, the nitrogen enters into the methanol leakage recovery system, and the methanol liquid in the U-shaped component is purged into the methanol daily cabin, and after the purging is completed, the remote control isolation valve is closed, so that the recovery of the methanol gas and liquid is realized.

[0021] The methanol leakage recovery step can also be used to provide a partial path for the nitrogen to purge the whole system before the system is started.

[0022] Further, the methanol fuel supply step further includes a liquid recovery step for the leakage of the heat exchange unit: the leaked liquid flows into the liquid receiving disc outside the heat exchange unit, the liquid level sensor on the leakage branch pipeline detects the methanol liquid, the first remote control stop valve is opened, the methanol liquid is discharged to the waste liquid cabin, and after the methanol liquid in the leakage branch pipeline is discharged, the first remote control stop valve is closed.

[0023] Compared with the prior art, the beneficial effects of the present application are:

[0024] (1) The filter of the present application is redundantly designed, one for use and one for standby, the standby filter can continue to work to replace the filter seriously clogged in the operation process, and the filter itself has a self-cleaning mechanism to automatically clean the clogged filter, and when the methanol fuel supply system stops running, the impurities cleaned from the inner surface of the filter return to the fuel sedimentation area of the methanol daily cabin together with the methanol fuel, thereby reducing the maintenance time of the filter.

[0025] (2) The low-level switch installed on the methanol daily cabin of the present application ensures that the pressure at the suction port meets the requirement of the net suction pressure head of the methanol supply pump, and provides a safety protection mechanism for the safe operation of the methanol supply pump.

[0026] (3) The low-level switch installed on the degassing tank of the present application provides a safety protection mechanism for the safe operation of the methanol circulating pump.

[0027] (4) The heat exchange unit of the present application is a double-wall plate heat exchanger, and the wall plate of the methanol fuel passage and the wall plate of the cold / heat source passage form an air gap, so that the intermediate heat exchange circulating loop between the methanol fuel supply system and the cold / heat source is no longer arranged, and space is saved.

[0028] (5) The reverse flushing pipeline is arranged on the cold / heat source inlet pipeline and the liquid return pipeline of the heat exchange unit, so that the wall plate forming the cold / heat source channel in the heat exchange unit can be flushed and cleaned, and the heat exchange efficiency of the heat exchange unit is maintained.

[0029] (6) The methanol leakage recovery system is also designed, wherein the U-shaped component is located at the lowest point of the system, which is beneficial to the centralized collection of the methanol fuel in the system, forms a methanol liquid column, and can effectively discharge the methanol fuel in the methanol leakage recovery system to the fuel precipitation area of the methanol daily cabin under the purging of nitrogen.

[0030] (7) The exhaust pipeline is provided at the relatively high point of the outlet pipeline of the methanol circulating pump, and the observation mirror for visual inspection is installed on the exhaust pipeline, so as to reduce the corrosion of the pipeline system during the operation of the methanol fuel supply system. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 It is a schematic diagram of the methanol supply system. DETAILED DESCRIPTION

[0032] The accompanying drawings in the embodiments are used to describe the technical solutions in the embodiments of the present application in more detail. In the drawings, the same or similar notations represent the same or similar elements or elements with the same or similar functions throughout. The described embodiments are part of the embodiments of the present application, but not all the embodiments. The embodiments described below by referring to the drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application. The embodiments of the present application are described in detail below with reference to the drawings.

[0033] It should be noted that if the directionality indication (such as up, down, left, right, front, back, etc.) is involved in the embodiments of the present application, the directionality indication is only used to explain the relative position relationship, movement condition, etc. between the components in a certain specific posture (as shown in the drawings), if the specific posture changes, the directionality indication also changes accordingly.

[0034] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0035] Example

[0036] like Figure 1 As shown, the present invention provides a methanol fuel supply system, comprising a methanol daily use tank 01, a coarse filter group 02, a methanol supply pump 03, a degassing tank 04, a methanol circulation pump 05, a heat exchange unit 06, a fine filter group 07, and a methanol consumption device 18 connected in sequence; the various components are connected by supply pipelines.

[0037] The methanol fuel supply system also includes a first control panel 15 and a second control panel 16. The first control panel 15 is used to control the fuel filling of the methanol day use tank 01 and the gas pressure in the space above the liquid level inside the tank. The second control panel 16 is used to control the operating status of the methanol fuel supply system.

[0038] The methanol daily use tank 01 includes a fuel settling area 11, a fuel supply area 12, and pipelines and instruments connected to the methanol daily use tank 01. The methanol daily use tank 01 is used to store methanol fuel for use by the methanol consumption equipment 18. The fuel settling area 11 and the fuel supply area 12 are separated by a partition 95 connecting the bottom and the tank wall of the methanol daily use tank 01. Impurities and oil in the methanol fuel accumulate at the bottom of the fuel settling area 11, and clean methanol fuel overflows through the top of the partition to the fuel supply area 12 for use by the methanol consumption equipment 18.

[0039] The piping on the methanol day tank 01 includes a methanol fuel injection line L15 and a venting line L16. The methanol fuel injection line L15 includes a fourth remote-controlled shut-off valve 70, which is controlled by a first control panel 15. The venting line L16 includes a first pressure regulating valve 68 and a pressure / vacuum valve 93 connected in parallel. The first pressure regulating valve 68, controlled by the first control panel 15, is used to regulate the pressure above the liquid surface in the methanol day tank 01 within a set range. The pressure / vacuum valve 93 is an automatically controlled valve used to maintain the pressure / vacuum level above the liquid surface in the methanol day tank 01 within the maximum permissible upper or lower limit.

[0040] The instrument on the daily-use cabin 01 of methanol includes a first pressure sensor X1, a high liquid level switch X2 and a first low liquid level switch X3, and signals are transmitted to the first control panel 15, the first pressure sensor X1 is used for monitoring the gas pressure of the upper space of the liquid surface in the daily-use cabin 01 of methanol, the high liquid level switch X2 is used for monitoring the maximum height of the liquid surface in the daily-use cabin 01 of methanol, and the first low liquid level switch X3 is used for monitoring the minimum height of the liquid surface in the daily-use cabin 01 of methanol.

[0041] The coarse filter group 02 of the application is a redundant design, one working and one standby, both filter components have automatic cleaning mechanisms, and are respectively provided with differential pressure sensors, the differential pressure sensor signals are transmitted to the second control panel 16, the two filters are switched through two remote control three-way valves, and the remote control three-way valves are controlled by the second control panel 16. When the pressure sensor of the filter on the working side detects that the inlet and outlet pressure difference reaches the set value, the filter on the other side is switched to work through the remote control three-way valve between the two filters. The self-cleaning mechanism of the coarse filter group is composed of a cleaning brush installed in the filter and a driving mechanism located at the top of the filter. When the filter on one side in the standby state performs the self-cleaning operation, the cleaning brush starts to rotate under the driving of the driving mechanism. The impurities attached to the inner surface of the filter screen will fall off in the process of rotation of the cleaning brush.

[0042] The fine filter 07 of the application is a redundant design, one working and one standby, both filters have automatic cleaning mechanisms, and are respectively provided with differential pressure sensors, the differential pressure sensor signals are transmitted to the second control panel 16, the two filters are switched through two remote control three-way valves, and the remote control three-way valves are controlled by the second control panel 16. When the pressure sensor of the filter on the working side detects that the inlet and outlet pressure difference reaches the set value, the filter on the other side is switched to work through the remote control three-way valve between the two filters. The self-cleaning mechanism of the fine filter 07 is composed of a cleaning brush installed in the filter and a driving mechanism located at the top of the filter. When the filter on one side in the standby state performs the self-cleaning operation, the cleaning brush starts to rotate under the driving of the driving mechanism. The impurities attached to the inner surface of the filter screen will fall off in the process of rotation of the cleaning brush.

[0043] The maximum flow provided by the methanol supply pump 03 is slightly higher than the maximum consumption of the methanol consumption device 18. The methanol supply pump 03 can be a fixed frequency pump or a variable frequency pump, which is used for first-stage pressurization of methanol fuel. The pressurized methanol fuel enters the degassing tank 04.

[0044] The degassing tank 04 is used to remove gas in the methanol fuel supply system and to stabilize the pressure at the inlet of the methanol circulating pump 05. The degassing tank 04 includes a high liquid level switch X6 and a low liquid level switch X7, which send signals to the second control panel 16. The high liquid level switch X6 is used to monitor the maximum height of the liquid level in the degassing tank 04, and the low liquid level switch X7 is used to monitor the minimum height of the liquid level in the degassing tank 04.

[0045] The methanol circulating pump 05 provides a maximum flow rate slightly higher than the maximum consumption of the methanol consuming device 18. The methanol circulating pump 05 can be a fixed frequency pump or a variable frequency pump, which is used to provide secondary pressurization for the methanol fuel to meet the pressure requirements of the methanol consuming device 18. The pressurized methanol fuel enters the methanol consuming device 18.

[0046] The heat exchange unit 06 is used to cool or heat the methanol fuel to meet the temperature requirements of the methanol consuming device 18. The heat exchange unit 06 is connected to a cooling / heating source through a cooling / heating return liquid pipeline L17 and a cooling / heating inlet liquid pipeline L18, and is also connected to other auxiliary pipelines. The cooling / heating inlet liquid pipeline L18 is provided with a remote temperature control valve 90, a manual shut-off valve 82, and a manual shut-off valve 83 connected in sequence, and the remote temperature control valve 90 is controlled by the second control panel 16. The cooling / heating return liquid pipeline L17 is also provided with a manual shut-off valve 80.

[0047] The auxiliary pipelines of the methanol fuel supply system include a bypass pipeline L19, a reverse flushing pipeline L20, and a reverse flushing pipeline L21. One end of the bypass pipeline L19 is connected to a port of the remote temperature control valve 90, and the other end is connected to a pipeline section between the manual shut-off valve 80 and the cooling / heating source on the cooling / heating return liquid pipeline L17, for directly flowing excess cooling / heating liquid into the cooling / heating return liquid pipeline L17.

[0048] The reverse flushing pipeline L20 is provided with a manual shut-off valve 81, one end of which is connected to a pipeline section between the manual shut-off valve 82 and the manual shut-off valve 83 on the cooling / heating inlet liquid pipeline L18, and the other end is connected to a pipeline section between the manual shut-off valve 80 and the heat exchange unit 06 on the cooling / heating return liquid pipeline L17. The reverse flushing pipeline L21 is also provided with a manual shut-off valve 79, one end of which is connected to a pipeline section between the manual shut-off valve 83 and the heat exchange unit 06 on the cooling / heating inlet liquid pipeline L18, and the other end is connected to a pipeline section between the manual shut-off valve 80 and the cooling / heating source on the cooling / heating return liquid pipeline L17.

[0049] The heat exchange unit 06 of the present application is a double-wall plate heat exchanger. The wall plate constituting the methanol fuel passage and the wall plate constituting the cold / hot source passage in the heat exchange unit 06 form an air gap therebetween. When leakage occurs in the wall plate of either the methanol fuel or the cold / hot source, the liquid on the other side will not be contaminated, and the leaked liquid will seep out from the surface of the heat exchange unit 06.

[0050] The methanol fuel supply system further comprises a liquid receiving tray 09 located outside the heat exchange unit 06 for collecting the liquid that seeps out when leakage occurs in the heat exchange unit 06. The liquid receiving tray 09 can be a fully enclosed structure or an open structure relative to the heat exchange unit 06. The methanol fuel supply system further comprises a waste liquid tank 17 for receiving the leaked liquid from the heat exchange unit 06.

[0051] The methanol fuel supply pipeline comprises a first supply pipeline L1 connecting the outlet of the methanol daily use tank 01 and the inlet of the coarse filter group 02, a second supply pipeline L2 connecting the outlet of the coarse filter group 02 and the inlet of the methanol supply pump 03, a third supply pipeline L3 connecting the outlet of the methanol supply pump 03 and the inlet of the degassing tank 04, a first bypass pipeline L10 of the third supply pipeline L3, a fourth supply pipeline L4 connecting the outlet of the degassing tank 04 and the inlet of the methanol circulating pump 05, a fifth supply pipeline L5 connecting the outlet of the methanol circulating pump 05 and the inlet of the heat exchange unit 06, a sixth supply pipeline L6 connecting the outlet of the heat exchange unit 06 and the inlet of the fine filter 07, and a seventh supply pipeline L7 connecting the outlet of the fine filter 07 and the inlet of the methanol consuming device 18.

[0052] The first supply pipeline L1 includes a first remote control isolation valve 65, which is controlled by the second control panel 16 and is closed when the methanol fuel supply system is shut down. The third supply pipeline L3 includes a check valve 23, a third manual stop valve 73, a flow meter X4, a fourth manual stop valve 72 and a pressure sensor X5 connected in sequence. The check valve 23 is used to prevent the methanol fuel in the methanol fuel supply system from flowing backward and impacting the methanol supply pump 03. The flow meter X4 is used to measure the amount of methanol fuel used. The fourth manual stop valve 72 and the third manual stop valve 73 are used to isolate the flow meter X4 from the pipeline to facilitate maintenance. The pressure sensor X5 is used to monitor the pressure of the methanol fuel in the third supply pipeline L3 and sends a signal to the second control panel 16. The fourth supply pipeline L4 includes a manual isolation valve 75, which is used to isolate the degassing tank 04 and the methanol circulating pump 05. The fifth supply pipeline L5 includes a check valve 24 and a sixth manual stop valve 77 connected in sequence. The check valve 24 is used to prevent the methanol fuel in the methanol fuel supply system from flowing backward and impacting the methanol circulating pump 05. The sixth manual stop valve 77 is used to isolate the methanol circulating pump 05 and the heat exchange unit 06. The sixth supply pipeline L6 includes a seventh manual stop valve 78, a temperature sensor X8 and a temperature switch X9 connected in sequence. The seventh manual stop valve 78 is used to isolate the heat exchange unit 06 and the fine filter 07. The temperature sensor X8 and the temperature switch X9 are used to monitor the temperature of the methanol fuel at the outlet of the heat exchange unit 06 and send a signal to the second control panel 16. The seventh supply pipeline L7 includes a third pressure sensor X11 and a sixth remote control stop valve 64 connected in sequence. The third pressure sensor X11 is used to monitor the pressure of the methanol fuel in the seventh supply pipeline L7 and sends a signal to the second control panel 16. The sixth remote control stop valve 64 is controlled by the second control panel 16 and is closed when the methanol fuel supply system is shut down.

[0053] The first bypass pipeline L10 includes a normally closed manual stop valve 74. One end of the first bypass pipeline L10 is connected to the upstream pipeline of the third manual stop valve 73 of the third supply pipeline L3, and the other end is connected to the downstream pipeline of the fourth manual stop valve 72 of the third supply pipeline L3. The first bypass pipeline L10 is used to provide a path for the methanol fuel to enter the degassing tank 04 when the flow meter X4 of the third supply pipeline L3 needs to be maintained.

[0054] The methanol fuel supply system further includes a first outlet pipeline connected to the first outlet pipeline of the methanol supply pump 03 and the first return pipeline L8 of the methanol daily tank 01, a third outlet pipeline connected to the fine filter 07, i.e. the seventh supply pipeline L7 and the second return pipeline L13 of the degassing tank 04.

[0055] The first methanol reflux pipeline L8 is provided with a pressure regulating valve 66, which is controlled by the second control panel 16, for regulating the flow and pressure of the methanol fuel in the third supply pipeline L3. The second methanol reflux pipeline L13 is further provided with a third pressure regulating valve 67, which is controlled by the second control panel 16, for regulating the flow and pressure of the methanol fuel in the seventh supply pipeline L7.

[0056] The methanol fuel supply system further comprises a methanol blowdown recovery system, which comprises a methanol blowdown pump 10, a U-shaped component 08 and a methanol blowdown pipeline. The methanol blowdown pump 10 is a pneumatic diaphragm pump, which is used to transport the methanol fuel in the methanol blowdown recovery system back to the methanol daily tank 01. The methanol blowdown recovery system further comprises a compressed air pipeline L22, which comprises a first hand-operated stop valve 84 and an air filter 14 connected in sequence, for providing power to the methanol blowdown pump 10.

[0057] The U-shaped component 08 is further provided with a second low liquid level switch X12. The U-shaped component 08 is located at the lowest point of the methanol blowdown recovery system, and the methanol fuel in the methanol blowdown system can flow into the U-shaped component 08. The second low liquid level switch X12 is used to monitor the height of the methanol fuel liquid in the U-shaped component, and the signal is transmitted to the second control panel 16.

[0058] The methanol blowdown pipeline further comprises a blowdown main pipeline L45 connected to the U-shaped component 08, a first blowdown branch pipeline L32 and a second blowdown branch pipeline L33 connected to the blowdown main pipeline L45 and the coarse filter group 02, a third blowdown branch pipeline L34 connected to the blowdown main pipeline L45 and the methanol supply pump 03, a fourth blowdown branch pipeline L36 connected to the blowdown main pipeline L45 and the pipeline section where the flow meter X4 is located, a fifth blowdown branch pipeline L37 connected to the blowdown main pipeline L45 and the first outlet pipeline of the methanol supply pump 03, a sixth blowdown branch pipeline L38 connected to the blowdown main pipeline L45 and the methanol circulation pump 05, a seventh blowdown branch pipeline L39 connected to the blowdown main pipeline L45 and the outlet pipeline of the methanol circulation pump 05, i.e. the fifth supply pipeline L5, an eighth blowdown branch pipeline L40 connected to the blowdown main pipeline L45 and the heat exchange unit 06, a ninth blowdown branch pipeline L41 connected to the waste liquid tank 17 and the liquid receiving disc 09 outside the heat exchange unit 06, a tenth blowdown branch pipeline L42 and an eleventh blowdown branch pipeline L43 connected to the blowdown main pipeline L45 and the fine filter 07, a twelfth blowdown branch pipeline L44 connected to the blowdown main pipeline L45 and the third outlet pipeline of the fine filter 07, i.e. the seventh supply pipeline L7, a thirteenth blowdown branch pipeline L14 connected to the U-shaped component 08 and the methanol blowdown pump 10, a fourteenth blowdown branch pipeline L47 connected to the methanol blowdown pump 10 and the methanol daily tank 01, and a second bypass pipeline L46 connected to the methanol blowdown pump 10 of the methanol daily tank 01.

[0059] First drain branch line L32, second drain branch line L33, and the rest of the drain branch lines L34, L37~L40, L42~L44, each provided with a remote control stop valve 50~56, 58~60, which are controlled by the second control panel 16, and the arrangement of the branch lines should not be less than the drain main line L45, for draining the methanol fuel in each pipe section of the methanol fuel supply system.

[0060] The fourth drain branch line L36 is provided with a second manual stop valve 71 and a first check valve 34 connected in sequence, for draining the pipe section between the third manual stop valve 73 upstream of the flow meter X4 and the fourth manual stop valve 72 downstream. The ninth drain branch line L41 is provided with a liquid level sensor X10 and a first remote control stop valve 57 connected in sequence, the liquid level sensor X10 is installed on the pipe at the lower part of the liquid receiving disc 09, and the signal is transmitted to the second control panel 16, which controls the first remote control stop valve 57. The thirteenth drain branch line L14 includes a remote control stop valve 62, which is controlled by the second control panel 16. The fourteenth drain branch line L47 includes a second check valve 22, a second remote control stop valve 61 and a third check valve 21 connected in sequence, the second check valve 22 is used to prevent the methanol fuel in the methanol drain recovery system from flowing backward and causing impact damage to the methanol drain pump 10, the second remote control stop valve 61 is controlled by the second control panel 16, and the third check valve 21 is used to prevent the methanol fuel and gas in the methanol daily tank 01 from flowing backward into the methanol drain recovery system. The methanol drain line also includes a second bypass line L46 of the methanol drain pump 10, which is installed with a third remote control stop valve 69 and a check valve 94, and the third remote control stop valve 69 is a normally open valve, which is controlled by the second control panel 16.

[0061] The methanol fuel supply system also includes a nitrogen purge system, which includes lines L23~L31 connected with the third supply line L3 between the methanol daily tank 01, the coarse filter group 02, the methanol supply pump 03 and the degassing tank 04, the degassing tank 04, the heat exchange unit 06, the fine filter 07 and the methanol drain main line L45.

[0062] The first nitrogen purge line L23 includes a second remote control isolation valve 41 and a check valve 25, the line L23 is connected with the top of the methanol daily tank 01, for injecting nitrogen into the space above the liquid surface in the methanol daily tank 01 to form a nitrogen seal and maintain the pressure in the space above the liquid surface within a set range, and the second remote control isolation valve 41 is controlled by the first control panel 15.

[0063] The nitrogen purging pipelines L24-L25, L27-L30 are respectively provided with remote control isolation valves 42-47 and check valves 26-27, and check valves 29-32. The nitrogen purging pipeline L24 and the nitrogen purging pipeline L25 are connected to the top of the coarse filter group 02. The nitrogen purging pipeline L27 is connected to the top of the degassing tank 04. The nitrogen purging pipeline L28 is connected to the top of the heat exchange unit 06. The nitrogen purging pipeline L29 and the nitrogen purging pipeline L30 are connected to the top of the fine filter 07. The remote control isolation valves 42-47 are controlled by the second control panel 16.

[0064] The nitrogen purging pipeline L26 includes a manual isolation valve 49 and a check valve 28. The nitrogen purging pipeline L26 is connected to the pipeline segment between the fourth manual stop valve and the third manual stop valve 73 on the third supply pipeline L3 of the methanol supply pipeline. The nitrogen purging pipeline L26 is used to purge the pipeline segment separated by the fourth manual stop valve and the third manual stop valve 73 when the flow meter X4 needs to be maintained, so as to avoid the contact between oxygen in the air and the methanol fuel to form a mixed gas.

[0065] The second nitrogen purging pipeline L31 includes a remote control isolation valve 48 and a check valve 33. The remote control isolation valve 48 is controlled by the second control panel 16. The second nitrogen purging pipeline L31 is connected to the methanol discharge main pipeline L45.

[0066] The methanol fuel supply system further includes a first exhaust pipeline L9 and a second exhaust pipeline L12. The first exhaust pipeline L9 is used for the exhaust of the degassing tank 04. The second exhaust pipeline L12 is used for the exhaust of the high point of the fifth supply pipeline L5 of the methanol circulating pump 05.

[0067] The first exhaust pipeline L9 is provided with a fifth remote control stop valve 63 connected in sequence. One end of the first exhaust pipeline L9 is connected to the discharge main pipeline L45. The other end is connected to the pipeline segment between the check valve 29 on the nitrogen purging pipeline L27 and the degassing tank 04. The fifth remote control stop valve 63 is controlled by the second control panel 16.

[0068] The second exhaust pipeline L12 is provided with a fifth manual stop valve 76 and a sight glass 91 connected in sequence. The second exhaust pipeline L12 is used to exhaust the gas accumulated at the relatively high point in the pipeline of the methanol fuel supply system before the system is operated. The sight glass 91 is used to visually check whether there is unexhausted gas in the first exhaust pipeline L9.

[0069] The methanol fuel supply system further comprises a pressure relief system, including a first pressure relief pipeline L11 and a second pressure relief pipeline L48. The first pressure relief pipeline L11 includes a first safety valve 88 which is automatically opened and closed, one end of which is connected to the top of the degassing tank 04, and the other end of which is connected to the methanol daily tank 01, and the gas and liquid discharged from the first pressure relief pipeline L11 flow back into the fuel precipitation area 11 on the methanol daily tank 01. The second pressure relief pipeline L48 includes a second safety valve 89 which is automatically opened and closed, one end of which is connected to the fifth supply pipeline L5 of the methanol circulating pump 05, and the other end of which is connected to the pipeline section between the first safety valve 88 on the first pressure relief pipeline L11 and the methanol daily tank 01, and the liquid discharged from the second pressure relief pipeline L48 flows back into the fuel precipitation area 11 on the methanol daily tank 01 through the methanol relief recovery system.

[0070] Specifically, the control method of the methanol fuel supply system of the present application is as follows.

[0071] Methanol is a toxic, low-flashpoint liquid, and when methanol is stored in the methanol daily tank 01, nitrogen needs to be filled into the space above the liquid level of the methanol to protect it. When the first pressure sensor X1 on the methanol daily tank 01 detects that the gas pressure in the space above the liquid level in the tank reaches the upper limit of the set range, the first pressure regulating valve 68 on the gas venting pipeline L16 is opened to discharge some nitrogen, and when the gas pressure returns to the set value, the first pressure regulating valve 68 is closed. When the first pressure sensor X1 on the methanol daily tank 01 detects that the gas pressure in the space above the liquid level in the tank reaches the lower limit of the set range, the second remote isolation valve 41 on the first nitrogen purging pipeline L23 is opened to fill in nitrogen, and when the gas pressure returns to the set value, the second remote isolation valve 41 is closed. If the gas pressure in the space above the liquid level in the methanol daily tank 01 cannot be restored to the set range, and the pressure / vacuum in the space above the liquid level in the methanol daily tank 01 reaches the maximum upper limit or lower limit allowed, the pressure / vacuum valve 93 on the gas venting pipeline L16 is automatically opened to discharge some nitrogen or fill in some air, so as to keep the pressure / vacuum in the space above the liquid level in the methanol daily tank within the maximum upper limit or lower limit allowed, thereby avoiding damage to the methanol daily tank 01.

[0072] When the methanol daily tank 01 is refueled with methanol fuel, the fourth remote shut-off valve 70 on the methanol fuel filling pipeline L15 is opened, and during the refueling process, the high-level switch X2 monitors the height of the methanol liquid level in the methanol daily tank 01, and when the height of the methanol liquid level reaches the position of the high-level switch X2, the fourth remote shut-off valve 70 is closed to stop refueling.

[0073] In order to ensure the normal operation of the methanol supply pump 03 and avoid cavitation on the impeller of the pump, the first low liquid level switch X3 is installed on the methanol daily tank 01 to monitor the minimum height of the allowable liquid level in the methanol daily tank 01. When the height of the methanol liquid level reaches the position of the first low liquid level switch X3, the operation of the methanol fuel supply system is stopped.

[0074] Before starting the methanol fuel supply system, nitrogen purging of the system is required. At this time, the first remote control isolation valve 65 on the first supply pipeline L1 and the sixth remote control stop valve 64 on the seventh supply pipeline L7 are in the closed state, the third remote control stop valve 69 on the second bypass pipeline L46 of the methanol bleed pump 10 is in the open state, the remote control stop valves 42-47 on the nitrogen purging pipelines L24, L25, L27-L30 and the remote control stop valves 50-56, remote control stop valve 58, remote control stop valve 59 on the first bleed branch pipeline L32, the second bleed branch pipeline L33 and the remaining bleed branch pipelines L34, L37, L38, L39, L40, L42, the eleventh bleed branch pipeline L43 are opened, and nitrogen is purged to the entire system. After purging is complete, close all remote control stop valves except the third remote control stop valve 69. Open the first remote control isolation valve 65 on the first supply pipeline L1, the fifth remote control stop valve 63 on the first exhaust pipeline L9 and the fifth manual stop valve 76 on the second exhaust pipeline L12, and let the methanol fuel in the methanol daily tank 01 flow into the methanol fuel supply system. When the high liquid level switch X6 on the degassing tank 04 detects the methanol liquid level in the tank, close the fifth remote control stop valve 63. At the same time, after observing the methanol fuel in the observation mirror 91 on the second exhaust pipeline L12, close the fifth manual stop valve 76.

[0075] When the methanol fuel supply system is started, the methanol supply pump 03 and the methanol circulating pump 05 begin to operate. At this time, the sixth remote control stop valve 64 on the seventh supply pipeline L7 is still in the closed state, the methanol supply pump 03 injects methanol fuel into the degassing tank 04, and the gas remaining in the degassing tank 04 is compressed in volume under the driving of the injected methanol liquid and accumulates at the top of the degassing tank 04. When the pressure sensor X5 on the third supply pipeline L3 detects that the pressure of the methanol fuel at the outlet of the methanol supply pump 03 reaches the upper limit of the set range, the pressure regulating valve 66 on the first methanol return pipeline L8 is opened, and all the methanol fuel at the outlet of the methanol supply pump 03 flows into the methanol daily tank 01 for circulation. At the same time, the third pressure sensor X11 on the seventh supply pipeline L7 also detects that the pressure of the methanol fuel at the outlet of the methanol circulating pump 05 reaches the upper limit of the set range, and the third pressure regulating valve 67 on the second methanol return pipeline L13 is opened, and all the methanol fuel at the outlet of the methanol circulating pump 05 flows into the degassing tank 04 for circulation. During the circulation process, the heat exchange unit 06 cools / heats the methanol fuel to make the temperature of the methanol fuel meet the requirements of the methanol consuming equipment 18.

[0076] When the temperature of the methanol fuel reaches the requirement of the methanol consuming device 18 after a period of circulation, the second control panel 16 opens the sixth remote cut-off valve 64 on the seventh supply line L7 to supply methanol to the methanol consuming device 18 upon receiving the command from the methanol consuming device 18. At this time, the pressure sensors of the methanol fuel in the third pressure sensor X11 on the seventh supply line L7 and the pressure sensor X5 on the third supply line L3 quickly monitor the pressure drop trend and send signals to the second control panel 16. The pressure regulating valve 66 on the methanol first return line L8 and the third pressure regulating valve 67 on the methanol second return line L13 are controlled by the second control panel 16 to reduce the valve opening degree accordingly, reduce the circulation amount of the methanol fuel, and ensure that the supply pressure of the methanol fuel in the pipeline at the pressure sensor X5 and the third pressure sensor X11 is stable within the set range. During the supply of the methanol fuel, the pressure of the methanol fuel is continuously monitored by the pressure sensor X5 on the third supply line L3 and the third pressure sensor X11 on the seventh supply line L7, and the circulation amount of the methanol fuel is adjusted in real time by adjusting the opening degree of the pressure regulating valve 66 on the methanol first return line L8 and the third pressure regulating valve 67 on the methanol second return line L13, so that the methanol fuel supplied to the methanol consuming device 18 meets the requirements of flow and pressure.

[0077] During the operation of the methanol fuel supply system, part of the heated methanol fuel will become methanol vapor. The methanol vapor returns to the degassing tank 04 together with the methanol liquid through the methanol second return line L13. When the accumulated gas reaches the position of the high liquid level switch X6 on the degassing tank 04, the fifth remote cut-off valve 63 on the first exhaust line L9 is opened, and the accumulated gas and part of the methanol liquid enter the discharge main line L45 through the first exhaust line L9. After a set period of exhaust process, the fifth remote cut-off valve 63 is closed, and the gas in the degassing tank 04 is exhausted.

[0078] The gas discharged from the first exhaust pipeline L9 enters the methanol daily cabin 01 through the methanol release recovery system, and part of the liquid is discharged into the U-shaped component 08 of the methanol release recovery system along with the gas flow. At this time, the second low liquid level switch X12 detects the methanol liquid and transmits a signal to the second control panel 16. The second control panel 16 opens the remote isolation valve 48 on the second nitrogen purge pipeline L31, and nitrogen enters the methanol release recovery system to purge the methanol liquid in the U-shaped component 08 into the methanol daily cabin 01. After the purging is completed, the remote isolation valve 48 is closed. The remote isolation valve 48 on the second nitrogen purge pipeline L31 is interlocked with the remote stop valves 42-47 on the nitrogen purge pipelines L24-L25 and L27-L30, the remote stop valves 50-56 and 58-60 on the release branch pipelines L32-L34, L37-L40 and L42-L44, and the fifth remote stop valve 63 on the first exhaust pipeline L9. That is, when the remote isolation valve 48 is opened, the other stop valves are closed, and vice versa.

[0079] During the operation of the methanol fuel supply system, when the flowmeter X4 needs to be maintained, the manual stop valve 74 on the first bypass pipeline L10 is opened, and the fourth manual stop valve 72 and the third manual stop valve 73 on the third supply pipeline L3 are closed, so that the methanol fuel enters the degassing tank 04 through the first bypass pipeline L10. Before removing the flowmeter X4, the manual isolation valve 49 on the nitrogen purge pipeline L26 and the second manual stop valve 71 on the fourth release branch pipeline L36 are opened. Under the purging of nitrogen, the methanol fuel between the fourth manual stop valve 72 and the third manual stop valve 73 is released to the methanol release recovery system. After the release is completed, the manual isolation valve 49 and the second manual stop valve 71 are closed. The liquid discharged from the fourth release branch pipeline L36 enters the U-shaped component 08 of the methanol release recovery system. At this time, the second low liquid level switch X12 detects the methanol liquid and opens the remote isolation valve 48 on the second nitrogen purge pipeline L31. Nitrogen enters the methanol release recovery system to purge the methanol liquid in the U-shaped component 08 into the fuel sedimentation area 11 on the methanol daily cabin 01. After the purging is completed, the remote isolation valve 48 is closed.

[0080] If the second nitrogen purge line L31 remote isolation valve 48 fails to open, the third remote shutoff valve 69 on the second bypass line L46 is closed, and the second remote shutoff valve 61 on the fourteenth drain branch line L47 and the remote shutoff valve 62 on the thirteenth drain branch line L14 are opened, and the methanol drain pump 10 is started to pump the methanol fuel in the U-shaped component 08 back into the fuel settling area 11 in the methanol service tank 01.

[0081] The low level switch X7 installed on the degassing tank 04 is used to ensure the normal operation of the methanol circulation pump 05 and to avoid the methanol circulation pump 05 running empty. During the operation of the methanol fuel supply system, when the liquid level in the degassing tank 04 drops to the position of the low level switch X7, the low level switch X7 is triggered, the operation of the methanol fuel supply system is stopped, and the sixth remote shutoff valve 64 on the seventh supply line L7 is closed.

[0082] The temperature sensor X8 on the sixth supply line L6 is used to monitor the temperature of the methanol fuel at the outlet of the heat exchange unit 06. If the heat exchange unit 06 is used to heat the methanol fuel, when the temperature of the methanol fuel is higher than the set value, the opening of the remote temperature control valve 90 on the inlet line L18 is adjusted to allow more heat source to enter the return line L17 through the bypass line L19; when the temperature of the methanol fuel is lower than the set value, the opening of the remote temperature control valve 90 is adjusted to allow more heat source to enter the heat exchange unit 06. If the heat exchange unit 06 is used to cool the methanol fuel, when the temperature of the methanol fuel is higher than the set value, the opening of the remote temperature control valve 90 is adjusted to allow more cold source to enter the heat exchange unit 06; when the temperature of the methanol fuel is lower than the set value, the opening of the remote temperature control valve 90 is adjusted to allow more cold source to enter the return line L17 through the bypass line L19.

[0083] The temperature switch X9 on the sixth supply line L6 is also used to monitor the temperature of the methanol fuel at the outlet of the heat exchange unit 06 to ensure that the temperature of the methanol fuel is within the maximum upper and lower limits allowed by the methanol consuming equipment 18. When the temperature of the methanol fuel exceeds the maximum upper or lower limit, the operation of the methanol fuel supply system is stopped, and the sixth remote shutoff valve 64 on the seventh supply line L7 is closed.

[0084] The manual stop valves 80 on the cooling / heating return liquid pipeline L17 and the manual stop valves 82-83 on the cooling / heating liquid pipeline L18 are normally open valves, the manual stop valve 81 on the reverse flushing pipeline L20 and the manual stop valve 79 on the reverse flushing pipeline L21 are normally closed valves. When the wall plate on the cold / hot source side of the heat exchange unit 06 needs to be cleaned, the manual stop valve 83 on the cooling / heating liquid pipeline L18 and the manual stop valve 80 on the cooling / heating return liquid pipeline L17 are closed, the manual stop valve 81 on the reverse flushing pipeline L20 and the manual stop valve 79 on the reverse flushing pipeline L21 are opened. After the reverse flushing is completed, the manual stop valve 83 and the manual stop valve 80 are opened, and the manual stop valve 81 and the manual stop valve 79 are closed.

[0085] During the operation of the methanol fuel supply system, if the heat exchange unit 06 leaks, the leaked liquid flows into the liquid receiving tray 09 outside the heat exchange unit 06. When the liquid level sensor X10 on the ninth discharge branch pipeline L41 detects the methanol liquid, the first remote control stop valve 57 is opened, and the methanol liquid is discharged into the waste liquid tank 17. After the methanol liquid in the ninth discharge branch pipeline L41 is discharged, the first remote control stop valve 57 is closed.

[0086] When the methanol consuming device 18 is temporarily stopped, the sixth remote control stop valve 64 on the seventh supply pipeline L7 is closed, and the methanol supply pump 03 and the methanol circulating pump 05 continue to operate. At this time, when the pressure sensor X5 on the third supply pipeline L3 detects that the pressure of the methanol fuel at the outlet of the methanol supply pump 03 reaches the upper limit of the set range, the third pressure regulating valve 66 on the first methanol return pipeline L8 is opened, and the methanol fuel at the outlet of the methanol supply pump 03 is completely circulated into the methanol daily tank 01. At the same time, when the third pressure sensor X11 on the seventh supply pipeline L7 detects that the pressure of the methanol fuel at the outlet of the methanol circulating pump 05 reaches the upper limit of the set range, the third pressure regulating valve 67 on the second methanol return pipeline L13 is opened, and the methanol fuel at the outlet of the methanol circulating pump 05 is completely circulated into the degassing tank 04. During the circulation process, the heat exchange unit 06 continues to cool / heat the methanol fuel to make the temperature of the methanol fuel meet the requirements of the methanol consuming device 18.

[0087] If the methanol consuming device 18 is not restarted within a set time after it is stopped, the first remote control isolation valve 65 on the first supply pipeline L1 is closed, and the operation of the methanol fuel supply system is stopped. Alternatively, the first remote control isolation valve 65 on the first supply pipeline L1 can be directly closed after the methanol consuming device 18 is stopped, and the operation of the methanol fuel supply system is stopped.

[0088] After the methanol fuel supply system stops running, the remote control isolation valves 42-47 on the nitrogen purge pipeline are opened, the remote control stop valves 50-56 and the remote control stop valves 58-60 are opened, the methanol fuel in the system is blown into the fuel sedimentation area 11 of the methanol daily tank 01 through the blow-off main pipeline L45 and the second bypass pipeline L46 under the action of nitrogen pressure, and after the blow-off in the set time is completed, the remote control isolation valves 42-47 on the nitrogen purge pipeline are closed, the remote control stop valves 50-56 and the remote control stop valves 58-60 on the blow-off branch pipeline are closed, and the inertization of the system is completed.

[0089] The above embodiments are only used to illustrate the technical solutions of the present application and not limit the present application. Although the present application has been described in detail with reference to the above preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the spirit and scope of the present application. Those skilled in the art can also make other changes within the spirit of the present application and use them in the design of the present application, as long as they do not deviate from the technical effects of the present application. These changes made in accordance with the spirit of the present application should be included in the scope of the present application.

Claims

1. A control method of a marine methanol fuel supply system, characterized by, The ship methanol fuel supply system comprises a methanol daily tank (01), a coarse filter group (02), a methanol supply pump (03), a degassing tank (04), a methanol circulating pump (05), a heat exchange unit (06), and a fine filter group (07) connected in sequence through a methanol supply pipeline system; the fine filter group (07) is externally connected to a methanol consumption device; The ship methanol fuel supply system further comprises a first control panel (15) and a second control panel (16); The methanol daily tank (01) is used for storing methanol fuel and is provided with a high liquid level switch (X2) and a first low liquid level switch (X3) for monitoring the liquid level of the methanol fuel in the methanol daily tank (01); The methanol supply pump (03) is used for pumping the methanol fuel in the methanol daily tank (01) and finally transmitting the methanol to the externally connected methanol consumption device; The coarse filter group (02) and / or the fine filter group (07) are redundantly designed and each comprises at least two filter members connected in parallel with each other, the filter members are provided with a self-cleaning mechanism, and the self-cleaning mechanism comprises a cleaning brush and a driving mechanism arranged at the top of the filter member; The first control panel (15) is used for controlling the fuel filling of the methanol daily tank (01) and the gas pressure in the upper space of the tank, and the second control panel (16) is used for controlling the operating state of the methanol fuel supply system; When the filter member on one side in the standby state performs the self-cleaning operation, the cleaning brush starts to rotate under the driving of the driving mechanism, and the impurities attached to the inner surface of the filter screen in the filter fall off in the process of rotation of the cleaning brush; The control method comprises the following steps: The control method comprises the following steps: The nitrogen blowing step, the maintenance step when the methanol is stored in the methanol daily tank (01), the methanol fuel filling step, the methanol fuel supply step, and the methanol discharge and recovery step; In the nitrogen blowing step, the first remote control isolation valve (65) on the first supply pipeline (L1) and the sixth remote control stop valve (64) on the seventh supply pipeline (L7) are in the closed state, the third remote control stop valve (69) on the second bypass pipeline (L46) of the methanol discharge pump (10) is in the open state, nitrogen is blown to the whole system, after the blowing is completed, the other remote control stop valves except the third remote control stop valve (69) are closed. The maintenance step is: when the methanol is stored in the methanol daily tank (01), when the gas pressure in the upper space of the liquid surface in the methanol daily tank (01) reaches the upper limit of the set range detected by the first pressure sensor (X1), the first pressure regulating valve (68) on the gas venting pipeline (L16) is opened, part of the nitrogen gas is discharged, and when the gas pressure returns to the set value, the first pressure regulating valve (68) is closed; when the gas pressure in the upper space of the liquid surface in the methanol daily tank (01) reaches the lower limit of the set range detected by the first pressure sensor (X1), the second remote control isolation valve (41) on the first nitrogen gas purging pipeline (L23) is opened, nitrogen gas is filled, and when the gas pressure returns to the set value, the second remote control isolation valve (41) is closed; when the gas pressure in the upper space of the liquid surface in the methanol daily tank (01) cannot be restored to the set range, and the pressure / vacuum degree of the upper space of the liquid surface in the methanol daily tank (01) reaches the allowed maximum upper limit or lower limit, the pressure / vacuum valve (93) on the gas venting pipeline (L16) is automatically opened, part of the nitrogen gas is discharged or part of the air is filled, and the pressure and vacuum degree of the upper space of the liquid surface in the methanol daily tank are maintained within the threshold range; The methanol fuel filling step is: the fourth remote control stop valve (70) on the methanol fuel filling pipeline (L15) is opened, when the height of the methanol liquid surface reaches the position of the high liquid level switch (X2), the fourth remote control stop valve (70) is closed, and the filling is stopped; during the filling process, the first pressure regulating valve (68) on the gas venting pipeline (L16) is opened, and part of the nitrogen gas in the methanol daily tank (01) replaced by the methanol fuel is discharged; The methanol fuel supply step includes: the sixth remote control stop valve (64) on the seventh supply pipeline (L7) is closed; the methanol supply pump (03) injects methanol fuel into the degassing tank (04), when the pressure of the methanol fuel at the outlet of the methanol supply pump (03) reaches the upper limit of the set range detected by the second pressure sensor (X5) on the third supply pipeline (L3), the second pressure regulating valve (66) on the first methanol return pipeline (L8) is opened, and the methanol fuel at the outlet of the methanol supply pump (03) flows into the methanol daily tank (01) for circulation; at the same time, when the pressure of the methanol fuel at the outlet of the methanol circulating pump (05) reaches the upper limit of the set range detected by the third pressure sensor (X11) on the seventh supply pipeline (L7), the third pressure regulating valve (67) on the second methanol return pipeline (L13) is opened, and the methanol fuel at the outlet of the methanol circulating pump (05) flows into the degassing tank (04) for circulation; during the circulation process, the heat exchange unit (06) cools / heats the methanol fuel to make the temperature of the methanol fuel meet the requirements of the external methanol consuming device (18); when the methanol consuming device (18) sends a fuel supply command to the second control panel (16), the second control panel (16) opens the sixth remote control stop valve (64) on the seventh supply pipeline (L7), and the required methanol fuel is delivered to the methanol consuming device (18); The methanol leakage recovery step includes a recovery step of recovering the methanol gas and part of the methanol liquid generated in the methanol fuel supply process and a purging step for purging the entire system with nitrogen before system start-up, the recovery step including: the methanol gas directly entering into the methanol daily tank (01) through a methanol leakage recovery system, part of the methanol liquid entering into the U-shaped component (08) with the gas flow, the methanol leakage recovery system including a second low liquid level switch (X12); the second low liquid level switch (X12) detecting the methanol liquid and transmitting a signal to the second control panel (16), the second control panel (16) opening the remote control isolation valve (48) on the second nitrogen purging pipeline (L31), nitrogen entering into the methanol leakage recovery system, purging the methanol liquid in the U-shaped component (08) into the methanol daily tank (01), and closing the remote control isolation valve (48) after purging is completed, to realize the recovery of the methanol gas and liquid.

2. The control method according to claim 1, characterized by, The heat exchange unit (06) is a double-wall plate heat exchanger, the double-wall plate heat exchanger including a first wall plate constituting a methanol fuel passage and a second wall plate constituting a cold / hot source passage, and a gas gap being formed between the first wall plate and the second wall plate, so that when leakage occurs on the wall plate of either side of the methanol fuel or the cold / hot source, the liquid on the other side will not be contaminated; The marine methanol fuel supply system further includes a liquid receiving tray (09) and a waste liquid tank (17); the liquid receiving tray (09) is arranged on the lower side of the outside of the heat exchange unit (06); and is used for collecting the liquid permeated out when leakage occurs in the heat exchange unit (06); The waste liquid tank (17) is arranged at the lower end of the liquid receiving tray (09) and is used for receiving the leakage liquid of the heat exchange unit (06).

3. The control method according to claim 1, characterized by, The methanol supply pipeline system includes a first supply pipeline (L1) connecting the outlet of the methanol daily tank (01) and the inlet of the coarse filter group (02), a second supply pipeline (L2) connecting the outlet of the coarse filter group (02) and the inlet of the methanol supply pump (03), a third supply pipeline (L3) connecting the outlet of the methanol supply pump (03) and the inlet of the degassing tank (04), a first bypass pipeline (L10) of the third supply pipeline (L3), a fourth supply pipeline (L4) connecting the outlet of the degassing tank (04) and the inlet of the methanol circulating pump (05), a fifth supply pipeline (L5) connecting the outlet of the methanol circulating pump (05) and the inlet of the heat exchange unit (06), a sixth supply pipeline (L6) connecting the outlet of the heat exchange unit (06) and the inlet of the fine filter group (07), and a seventh supply pipeline (L7) connecting the outlet of the fine filter group (07) and the inlet of the methanol consumption device (18); The methanol supply pipeline system further includes a first outlet pipeline connected with the methanol supply pump (03) and a first return pipeline (L8) connected with the methanol daily tank (01), and a third outlet pipeline connected with the fine filter group (07) and a second return pipeline (L13) connected with the degassing tank (04); the first outlet pipeline and the third supply pipeline (L3) are the same pipeline; and the third outlet pipeline and the seventh supply pipeline (L7) are the same pipeline.

4. The control method according to claim 3, characterized by The methanol leakage recovery system further comprises a methanol leakage pump (10), a U-shaped component (08), a methanol leakage pipeline and a compressed air pipeline (L22); The methanol leakage pump (10) is a pneumatic diaphragm pump, which is used to transport the methanol fuel in the methanol leakage recovery system back to the methanol daily cabin (01); The compressed air pipeline (L22) comprises a first manual stop valve (84) and an air filter (14) connected in sequence, which is used to provide power for the methanol leakage pump (10); The U-shaped component (08) is provided with a second low liquid level switch (X12) on one side, and the U-shaped component (08) is arranged at the lowest point of the methanol leakage recovery system. The methanol fuel in the methanol leakage system flows into the U-shaped component (08), and the second low liquid level switch (X12) is used to monitor the height of the methanol fuel liquid in the U-shaped component (08); The methanol leakage pipeline comprises a leakage main pipeline (L45) connected to the U-shaped component (08), a first leakage branch pipeline (L32) and a second leakage branch pipeline (L33) connected to the leakage main pipeline (L45) and the coarse filter group (02), a third leakage branch pipeline (L34) connected to the leakage main pipeline (L45) and the methanol supply pump (03), a fourth leakage branch pipeline (L36) connected to the leakage main pipeline (L45) and the pipe section where the flow meter (X4) is located, a fifth leakage branch pipeline (L37) connected to the leakage main pipeline (L45) and the first outlet pipeline of the methanol supply pump (03), a sixth leakage branch pipeline (L38) connected to the leakage main pipeline (L45) and the methanol circulation pump (05), a seventh leakage branch pipeline (L39) connected to the leakage main pipeline (L45) and the second outlet pipeline of the methanol circulation pump (05), an eighth leakage branch pipeline (L40) connected to the leakage main pipeline (L45) and the heat exchange unit (06), a ninth leakage branch pipeline (L41) connected to the waste liquid cabin (17) and the liquid receiving disc (09) outside the heat exchange unit (06), a tenth leakage branch pipeline (L42) and an eleventh leakage branch pipeline (L43) connected to the leakage main pipeline (L45) and the fine filter group (07), a twelfth leakage branch pipeline (L44) connected to the leakage main pipeline (L45) and the third outlet pipeline of the fine filter group (07), a thirteenth leakage branch pipeline (L14) connected to the U-shaped component (08) and the methanol leakage pump (10), a fourteenth leakage branch pipeline (L47) connected to the methanol leakage pump (10) and the methanol daily cabin (01), and a second bypass pipeline (L46) connected to the methanol leakage pump (10) of the methanol daily cabin (01), wherein the second outlet pipeline and the fifth supply pipeline (L5) are the same pipeline.

5. The control method according to claim 4, characterized by A plurality of remote control stop valves are arranged on the methanol leakage pipeline, which are used to discharge the methanol fuel in each pipeline section of the methanol fuel supply system. The fourth drain branch line (L36) comprises a second hand-operated stop valve (71) and a first check valve (34) connected in sequence, and is used for draining the pipe section between the third hand-operated stop valve (73) upstream of the flowmeter (X4) and the fourth hand-operated stop valve (72) downstream. The ninth drain branch line (L41) comprises a liquid level sensor (X10) and a first remote control stop valve (57) connected in sequence, the liquid level sensor (X10) is installed on the pipe line at the lower part of the liquid receiving disc (09), and signals are transmitted to the second control disc (16) to control the first remote control stop valve (57). The fourteenth drain branch line (L47) comprises a second check valve (22), a second remote control stop valve (61) and a third check valve (21) connected in sequence; the second remote control stop valve (61) is controlled by the second control disc (16).

6. The control method according to claim 1, characterized by, The nitrogen purging pipe line system for purging the methanol fuel supply system of the ship comprises a plurality of pipes connected between the methanol daily tank (01), the coarse filter group (02), the methanol supply pump (03) and the degassing tank (04) respectively, and the degassing tank (04), the heat exchange unit (06), the fine filter group (07) and the methanol drain main pipe line (L45); a plurality of remote control isolation valves and a plurality of check valves arranged on the pipes; the remote control isolation valves are controlled by the first control disc (15) or the second control disc (16).

7. The control method according to claim 6, characterized by The first exhaust pipe line (L9) is used for exhausting the degassing tank (04), and the second exhaust pipe line (L12) is used for exhausting the high point of the outlet pipe line of the methanol circulating pump (05); The fifth remote control stop valve (63) is arranged on the first exhaust pipe line (L9), one end of the first exhaust pipe line (L9) is connected with the drain main pipe line (L45), the other end is connected with the nitrogen purging pipe line system, and the fifth remote control stop valve (63) is controlled by the second control disc (16); The second exhaust pipe line (L12) comprises a fifth hand-operated stop valve (76) and a sight glass (91) connected in sequence, and the sight glass (91) is used for visually checking whether there is unexhausted gas in the first exhaust pipe line (L9).

8. The control method according to claim 1, characterized by, The pressure relief system comprises a first pressure relief pipe line (L11) and a second pressure relief pipe line (L48); The first pressure relief pipe line (L11) is provided with an automatically opened and closed first safety valve (88), one end of the first pressure relief pipe line (L11) is connected with the top of the degassing tank (04), the other end is connected with the methanol daily tank (01), and the gas and liquid exhausted from the first pressure relief pipe line (L11) flow back into the fuel precipitation area (11) of the methanol daily tank (01). The second pressure relief pipeline (L48) is provided with an automatically opened and closed second safety valve (89), one end of which is connected with the fifth supply pipeline (L5) of the methanol circulating pump (05), and the other end is connected with the pipeline section between the first safety valve (88) on the first pressure relief pipeline (L11) and the methanol daily-use tank (01), and the liquid discharged from the second pressure relief pipeline (L48) flows back to the fuel precipitation area (11) in the methanol daily-use tank (01) through the methanol leakage recovery system.

9. The control method according to claim 1, characterized by, The methanol fuel supply step further comprises a liquid recovery step for the case that the heat exchange unit (06) leaks: the leaked liquid flows into the liquid receiving tray (09) outside the heat exchange unit (06), after the liquid level sensor (X10) on the leakage branch pipeline (L41) detects the methanol liquid, the first remote control stop valve (57) is opened, the methanol liquid is discharged to the waste liquid tank (17), and after the methanol liquid in the leakage branch pipeline (L41) is discharged, the first remote control stop valve (57) is closed.

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