Marine methanol fuel storage and supply and volatile gas recovery system

Abstract

A marine methanol fuel storage and supply and volatile gas recovery system comprises a fuel supply unit, a connector which is connected with a methanol fuel engine and conveys methanol fuel to the methanol fuel engine, a storage unit which is connected with the fuel supply unit and supplements and conveys the methanol fuel to the fuel supply unit, and a volatile gas recovery unit which is connected with the storage unit and conveys the methanol fuel to the fuel supply unit. The volatile gas recovery unit is used for introducing volatile gas from the storage unit and sending recovered methanol back to the storage unit after treatment, and the utility unit is respectively connected with the fuel supply unit, the storage unit and the volatile gas recovery unit and provides auxiliary media including a refrigerant, steam, seawater, fresh water and nitrogen; the system adopts the following process measures: conveying of daily methanol, supply of methanol fuel of an engine, collection of accident methanol, recovery of volatile gas, cooling of a coil pipe and supply of public engineering. A volatile gas recovery technology is adopted, stable storage and reliable supply of methanol fuel are achieved, meanwhile, high recovery rate and up-to-standard emission of volatile gas are achieved, and the method has the advantages of being complete in process and safe in operation.

Description

Technical Field

[0001] The invention relates to a fuel system of a marine low-speed diesel engine, in particular to a marine methanol fuel storage and supply and volatile gas recovery system, belonging to the technical field of marine diesel engines. Background Art

[0002] In recent years, under the background of the International Maritime Organization strengthening emission regulations and the global industry accelerating carbon reduction, reducing ship emissions has become an important task for the shipping industry. Compared with traditional fuel engines, methanol dual-fuel low-speed diesel engines can reduce 97% of sulfur compounds and 50% of nitrogen oxide emissions, particulate matter emissions can also be reduced by 90%, and greenhouse gas emissions can be reduced by 11%. With the innovation and development of methanol dual-fuel diesel engine technology, methanol dual-fuel diesel engines are increasingly favored by the market, and it is also a general trend for ships to be equipped with green and energy-saving methanol dual-fuel diesel engines in the future.

[0003] Methanol is an environmentally friendly and clean liquid fuel with the advantages of good economy and high combustion efficiency. However, methanol is colorless, transparent, flammable, volatile and toxic, which can cause harm to personnel and cause ship fires. If methanol leaks, it will inevitably pose a huge threat to the safe and reliable operation of ships. Therefore, it is extremely necessary to develop a ship-based methanol fuel storage and supply and volatile gas recovery process to achieve a safe and reliable supply of methanol fuel. Summary of the invention

[0004] The purpose of the present invention is to provide a marine methanol fuel storage and supply and volatile gas recovery system in view of the characteristics of methanol fuel being volatile and toxic and having potential safety hazards, which can adapt to the situation where the ship has limited space and strict safety requirements, realize the stable and reliable storage and demand supply of methanol fuel, and at the same time realize the recovery and utilization of methanol volatile gas to achieve the requirement of near zero emission.

[0005] In order to achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0006] A marine methanol fuel storage and supply and volatile gas recovery system, connected to a methanol fuel engine, characterized in that the system comprises:

[0007] A fuel supply unit, connected to the methanol fuel engine and delivering methanol fuel to the interface of the methanol fuel engine, including a methanol daily cabinet, a methanol variable frequency pump, a methanol heater, a fuel valve group and a methanol flow meter;

[0008] A storage unit connected to the fuel supply unit and supplying methanol fuel to the fuel supply unit, including a 1# methanol storage tank, a 2# methanol storage tank, a fixed-frequency fuel supply pump group and an emergency fuel extraction pump;

[0009] A volatile gas recovery unit is connected to the storage unit, introduces volatile gas from the storage unit, and after treatment, returns the recovered methanol to the storage unit, including an explosion-proof induced draft fan, a volatile gas condenser, a gas-liquid separator, a methanol recovery pump, a volatile gas water washing tower, a primary methanol detector, an activated carbon adsorption tank, a secondary methanol detector, a methanol aqueous solution storage tank, a circulating water pump, a methanol purification tower, a reboiler, a condenser, a tower top gas-liquid separator, a methanol recovery tank, a recycled methanol circulating pump, a tower bottom water pump and a cooler;

[0010] The utility unit is respectively connected to the fuel supply unit, the storage unit and the volatile gas recovery unit, and provides auxiliary media including refrigerant, steam, seawater, fresh water and nitrogen for the fuel supply unit, the storage unit and the volatile gas recovery unit.

[0011] As a further improvement, the methanol fuel in the methanol daily cabinet is transported to the methanol heater through the methanol variable frequency pump, and is sent to the fuel valve group after being heated by low-pressure steam. After switching, purging, discharging and flow regulation in the fuel valve group, the methanol fuel is measured by the methanol flowmeter and finally transported to the interface of the methanol fuel engine.

[0012] As a further improvement, the methanol fuel from the 1# methanol storage tank and the 2# methanol storage tank of the storage unit is transported to the methanol daily cabinet of the fuel supply unit through the fixed-frequency fuel supply pump group, and the methanol leaked in the fixed-frequency fuel supply pump group is sent back to the 1# methanol storage tank through the accident fuel extraction pump.

[0013] As a further improvement, the volatile gas from the 1# methanol storage cabinet and the 2# methanol storage cabinet of the storage unit is pressurized by the explosion-proof induced draft fan of the volatile gas recovery unit and then transported to the hot gas side of the volatile gas condenser, wherein most of the gaseous methanol is condensed into liquid methanol by the refrigerant, and the volatile gas mixed with gas and liquid phases is then transported to the gas-liquid separator, and the separated volatile gas enters the volatile gas water washing tower from the bottom, and is countercurrently contacted with the circulating water from the top of the tower, and most of the methanol is converted into methanol aqueous solution after being washed with water, and then discharged from the bottom of the tower into the methanol aqueous solution storage tank, while the volatile gas containing very little methanol is discharged from the top of the volatile gas water washing tower, and enters the activated carbon adsorption tank after the first-level methanol detector monitors the methanol concentration, and the volatile gas after activated carbon adsorption is then monitored by the second-level methanol detector for methanol concentration, and is discharged externally after being confirmed to meet the standard; the liquid methanol separated in the gas-liquid separator is transported to the methanol recovery tank through the methanol recovery pump tank, the liquid methanol in the methanol recovery tank is transported back to the 1# methanol storage cabinet and the 2# methanol storage cabinet of the storage unit through the methanol recovery circulation pump; the circulating water pump merges part of the methanol aqueous solution in the methanol aqueous solution storage tank with fresh water, and sends it to the volatile gas water washing tower for recycling, and sends another part of the methanol aqueous solution to the methanol purification tower for purification and recovery of the methanol aqueous solution; the reboiler at the bottom of the methanol purification tower reheats and evaporates the methanol aqueous solution, and the high-concentration gaseous methanol is sent out from the top of the tower, and enters the gas-liquid separator at the top of the tower after condensation by the condenser, and the condensed methanol is sent to the methanol recovery tank through the methanol recovery pump, and the non-condensable gaseous methanol is discharged from the top of the gas-liquid separator at the top of the tower and sent to the activated carbon adsorption tank, and finally the methanol concentration is monitored by the secondary methanol detector, and it is discharged to the outside after confirmation that it meets the standard; the high-temperature circulating water at the bottom of the methanol purification tower is sent to the cooler through the tower bottom water pump, and enters the methanol aqueous solution storage tank for recycling after cooling.

[0014] As a further improvement, sealed compartments are provided on the periphery of the methanol daily cabinet, 1# methanol storage cabinet and 2# methanol storage cabinet.

[0015] As a further improvement, the storage unit is provided with n methanol storage cabinets and n sealed compartments, wherein n is a natural number.

[0016] As a further improvement, an accident collection pool is arranged around the methanol variable frequency pump and the fixed frequency fuel supply pump group.

[0017] As a further improvement, the emergency fuel extraction pump is arranged in the emergency collection tank of the fixed frequency fuel supply pump group.

[0018] As a further improvement, the volatile gas recovery unit uses condensation recovery, gas-liquid separation, water washing, purification and adsorption processes to treat the volatile gas.

[0019] As a further improvement, the 1# methanol storage cabinet and the 2# methanol storage cabinet use internal coils to adjust the methanol storage temperature via refrigerant to suppress the volatilization of methanol.

[0020] As a further improvement, the tops of the 1# methanol storage tank and the 2# methanol storage tank are sprayed to cool the recovered low-temperature methanol to further reduce the amount of methanol volatilization.

[0021] As a further improvement, the refrigerant is ethylene glycol solution or lithium bromide solution.

[0022] As a further improvement, the system adopts the following process measures:

[0023] 1) Delivery of daily methanol: the storage unit is used as a total methanol fuel storage cabinet, and the fixed-frequency fuel supply pump group delivers methanol to the methanol daily cabinet of the fuel supply unit;

[0024] 2) Supply of methanol fuel engine fuel: When the engine is switched into the methanol combustion working mode, the methanol variable frequency pump is started to deliver the methanol in the methanol daily cabinet to the methanol heater, and the heated methanol is continuously delivered to the fuel valve group, and after switching and adjustment, it is delivered to the methanol flowmeter for metering, and then delivered to the interface of the methanol fuel engine, so as to supply the corresponding methanol fuel according to the engine load;

[0025] 3) Collection of accidental methanol: Sealed compartments are set in the 1# methanol storage cabinet, 2# methanol storage cabinet and methanol daily cabinet to prevent leakage accidents from spilling out, and accident collection pools are set in the fixed-frequency fuel supply pump group and the methanol variable-frequency pump, wherein the accident collection pools of the methanol daily cabinet, the methanol variable-frequency pump and the fixed-frequency fuel supply pump group are equipped with accident fuel extraction pumps to extract the leaked methanol to the 1# methanol storage cabinet;

[0026] 4) Recovery of volatile gas: The volatile gas is introduced into the volatile gas recovery unit through the explosion-proof induced draft fan, and most of the methanol is recovered and discharged in compliance with the standards after condensation, gas-liquid separation, water washing, and adsorption treatment. The methanol-water solution washed with water is purified by distillation to separate methanol and water, and the water is recycled as washing water. The liquid methanol is pumped to the 1# methanol storage tank and the 2# methanol storage tank for recovery, and the top is sprayed for cooling to reduce the methanol respiration volume;

[0027] 5) Coil cooling: The methanol storage temperature is controlled by cooling the internal coil with refrigerant to suppress the methanol respiration;

[0028] 6) Utility supply: A reasonably matched utility unit is set up to provide a stable auxiliary medium supply for the refrigerant, steam, seawater, fresh water and nitrogen used in the marine methanol fuel storage and supply and volatile gas recovery system.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] (1) It is suitable for the storage and supply of marine methanol fuel and has the characteristics of perfect technology, safe operation, comprehensive functions, and reliable environmental protection.

[0031] (2) Safe and reliable volatile gas recovery technology is adopted to achieve a high volatile gas recovery rate and meet emission standards.

[0032] (3) The storage temperature of methanol is controlled by using coil cooling and low-temperature spraying, which ensures the safe storage of methanol and the low volatility and loss of methanol. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a system principle diagram of the present invention.

[0034] Figure 2 This is a schematic diagram of the storage unit process.

[0035] Figure 3 This is the process schematic diagram of the fuel supply unit.

[0036] Figure 4 This is the process schematic diagram of the volatile gas recovery unit.

[0037] Figure 5 This is the process schematic diagram of the public engineering unit.

[0038] In the figure:

[0039] V101—1# methanol storage cabinet, V102—2# methanol storage cabinet, P101—fixed frequency fuel supply pump group, P102—accident fuel extraction pump, V201—methanol daily cabinet, P201—methanol variable frequency pump, E201—methanol heater, FVT01—fuel valve group, FM201—methanol flowmeter, C301—explosion-proof induced draft fan, E301—volatile gas condenser, E302—reboiler, E303—condenser, E304—cooling device, V301—gas-liquid separator, V302—methanol recovery tank, V303—methanol water solution storage tank, V304—tower top gas-liquid separator, P301—methanol recovery pump, P302—circulating water pump, P303—tower bottom water pump, P304—recovered methanol circulating pump, T301—volatile gas water washing tower, T302—methanol purification tower, X301—activated carbon adsorption tank, GT01—primary methanol detector, GT02—secondary methanol detector. DETAILED DESCRIPTION

[0040] The present invention is used for the storage, supply and recovery of marine methanol fuel, realizing safe and reliable storage and supply of methanol fuel, and at the same time realizing the recovery and utilization of methanol volatile gas, thus meeting the requirement of nearly zero emission.

[0041] The preferred embodiments of the present invention are specifically listed in the following examples, but it should be understood that the protection scope of the present invention is not limited thereto.

[0042] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0043] Example

[0044] This embodiment sees Figure 1 As shown, the marine methanol fuel storage and supply and volatile gas recovery system consists of a storage unit, a fuel supply unit, a volatile gas recovery unit and a public engineering unit; wherein the fuel supply unit is connected to the methanol fuel engine and delivers the methanol fuel to the interface of the methanol fuel engine, the storage unit is connected to the fuel supply unit, and replenishes the methanol fuel to the fuel supply unit, the volatile gas recovery unit is connected to the storage unit, introduces the volatile gas from the storage unit, and after treatment, returns the recovered methanol to the storage unit, and the public engineering unit is respectively connected to the fuel supply unit, the storage unit and the volatile gas recovery unit and provides auxiliary media including refrigerant, steam, seawater, fresh water and nitrogen.

[0045] See also Figure 2 The storage unit includes 1# methanol storage cabinet V101, 2# methanol storage cabinet V102, fixed frequency fuel supply pump group P101, accident fuel extraction pump P102, methanol storage cabinet sealed compartment and fuel supply pump accident collection pool. The bottoms of the 1# methanol storage cabinet V101 and 2# methanol storage cabinet V102 are respectively connected to the inlet of the fixed frequency fuel supply pump group P101 through pipelines, the outlet of the fixed frequency fuel supply pump group P101 is connected to the fuel supply unit through a pipeline, the inlet of the accident fuel extraction pump P102 is connected to the bottom of the fuel supply pump accident collection pool through a pipeline, and the outlet of the accident fuel extraction pump P102 is connected to the top of the 1# methanol storage cabinet V101 through a pipeline. An accident collection pool is set outside the fixed frequency fuel supply pump group P101. When a leak occurs in the skid, the leaked methanol can be pumped into the 1# methanol storage cabinet V101 through the accident fuel extraction pump P102.

[0046] See also Figure 3The fuel supply unit comprises a methanol daily cabinet V201, a methanol variable frequency pump P201, a methanol heater E201, a fuel valve group FVT01, a methanol flow meter FM201, a methanol daily cabinet sealed compartment and a methanol variable frequency pump accident collection pool. The top of the methanol daily cabinet V201 is connected to the outlet of the fixed frequency fuel supply pump group P101 of the storage unit through a pipeline, and the methanol fuel is replenished by it. The bottom outlet of the methanol daily cabinet V201 is connected to the inlet of the methanol variable frequency pump P201 through a pipeline, the outlet of the methanol variable frequency pump P201 is connected to the inlet of the methanol heater E201 (cold side) through a pipeline, the cold side outlet of the methanol heater E201 is connected to the inlet of the fuel valve group FVT01 through a pipeline, the outlet of the fuel valve group FVT01 is connected to the methanol flow meter FM201 through a pipeline, and the outlet of the methanol flow meter FM201 (for fuel consumption measurement) is connected to the engine fuel pipe port through a pipeline. The methanol daily cabinet V201 is equipped with a sealed compartment to prevent methanol from leaking into the engine room. The methanol variable frequency pump P201 is equipped with an accident collection pool. When leakage occurs in the methanol daily cabinet V201 and the methanol variable frequency pump P201 skid, the accident fuel extraction pump P102 can automatically extract and transport it back to the 1# methanol storage cabinet V101 to avoid the expansion of the leakage accident.

[0047] See also Figure 4The volatile gas recovery unit includes explosion-proof induced draft fan C301, volatile gas condenser E301, gas-liquid separator V301, methanol recovery pump P301, volatile gas water washing tower T301, primary methanol detector GT01, activated carbon adsorption tank X301, secondary methanol detector GT02, methanol aqueous solution storage tank V303, circulating water pump P302, methanol purification tower T302, reboiler E302, condenser E303, tower top gas-liquid separator V304, methanol recovery tank V302, tower bottom water pump P303, recovered methanol circulating pump P304 and cooler E304. The volatile gas at the top of the 1# methanol storage cabinet V101 and the 2# methanol storage cabinet V102 is connected to the inlet of the explosion-proof induced draft fan C301 through a pipeline, the outlet of the explosion-proof induced draft fan C301 is connected to the inlet of the volatile gas condenser E301 (hot side) through a pipeline, the outlet of the volatile gas condenser E301 (hot side) is connected to the inlet of the gas-liquid separator V301 through a pipeline, the gas phase outlet of the gas-liquid separator V301 is connected to the gas phase inlet at the bottom of the volatile gas washing tower T301 through a pipeline, the bypass line of the gas phase outlet pipeline at the top of the tower is provided with the first-level methanol detector GT01, the gas phase outlet is finally connected to the inlet of the activated carbon adsorption tank X301 through a pipeline, the outlet of the activated carbon adsorption tank X301 is provided with the second-level methanol detector GT02, and the outlet is finally discharged into the atmosphere. The liquid phase outlet at the bottom of the volatile gas washing tower T301 is connected to the inlet of the methanol aqueous solution storage tank V303 through a pipeline, and the outlet of the methanol aqueous solution storage tank V303 is connected to the inlet of the circulating water pump P302 through a pipeline. The outlet of the circulating water pump P302 is divided into two branch pipelines, one of which is connected to the liquid phase inlet of the top of the volatile gas washing tower T301 after merging with the temporary supplementary fresh water, and the other branch pipeline is connected to the material inlet in the middle of the methanol purification tower T302. The methanol aqueous solution in the methanol purification tower T302 is distilled and discharged from the top of the tower with high concentration gas phase methanol. The gas phase outlet at the top of the tower is connected to the inlet of the condenser E303 (hot side) through a pipeline, and the outlet of the condenser E303 (hot side) is connected to the inlet of the tower top gas-liquid separator V304 through a pipeline. The final condensed methanol is sent to the inlet of the methanol recovery pump P301 from the liquid phase outlet at the bottom of the tower top gas-liquid separator V304, and the non-condensable gas phase methanol is connected to the inlet of the activated carbon adsorption tank X301 through a pipeline. The high-temperature circulating water at the bottom of the methanol purification tower T302 is connected to the inlet of the tower kettle water pump P303 through a pipeline, and the outlet of the tower kettle water pump P303 is connected to the inlet of the cooler E304 (hot side) through a pipeline, and the outlet of the cooler (hot side) is connected to another inlet of the methanol aqueous solution storage tank V303 through a pipeline. The liquid phase outlet at the bottom of the gas-liquid separator V301 is connected to the inlet of the methanol recovery tank V302 through a pipeline, and the outlet at the bottom of the methanol recovery tank V302 is connected to the spray pipe inlet at the top of the 1# methanol storage cabinet V101 and the 2# methanol storage cabinet V102 through a pipeline.

[0048] See also Figure 5 The utility unit includes five types of public medium materials, including low temperature-circulating refrigerant (refrigerator), low pressure steam-condensed water, fresh water, sea water and nitrogen. The refrigerant system provides cooling medium for the volatile gas condenser E301, 1# methanol storage cabinet V102 and 2# methanol storage cabinet V102 respectively. Low pressure steam provides heating medium for the reboiler E302 and the methanol heater E201 respectively. Fresh water is used to supplement the water loss due to evaporation of the volatile gas washing tower T301. Seawater is used to provide cooling medium for the condenser E303 and for heat exchange cooling of high temperature circulating water. Nitrogen is used for nitrogen sealing of 1# methanol storage cabinet V101 and 2# methanol storage cabinet V102 and purging and purification inside the fuel valve group FVT01.

[0049] The present invention includes the following process contents:

[0050] (1) Daily methanol transportation: The 1# methanol storage tank and 2# methanol storage tank of the storage unit serve as the total methanol fuel storage tanks, which are used to replenish the methanol daily tanks of the fuel supply unit. Methanol is transported to the methanol daily tanks through a fixed-frequency fuel supply pump group.

[0051] (2) Engine fuel supply: When the engine enters the methanol combustion mode, the corresponding methanol fuel needs to be supplied according to the engine load. The methanol in the methanol daily cabinet can be pumped to the methanol heater by starting the methanol variable frequency pump. After heating, the methanol is continuously transported to the fuel valve group, and then sent to the methanol flowmeter after switching and adjustment. After metering, the methanol is transported to the engine methanol fuel interface.

[0052] (3) Accident methanol collection: In view of the toxicity of methanol, leakage can easily lead to safety accidents. Therefore, the 1# methanol storage cabinet, 2# methanol storage cabinet, methanol daily cabinet, fixed-frequency fuel supply pump group and methanol variable frequency pump are prone to leakage and high risk of accident expansion. The 1# methanol storage cabinet, 2# methanol storage cabinet and methanol daily cabinet are all equipped with sealed compartments to prevent leakage accidents from spilling out. The fixed-frequency fuel supply pump group and methanol variable frequency pump are both equipped with accident collection pools. The methanol daily cabinet and methanol variable frequency pump are equipped with accident fuel extraction pumps, which can extract the leaked methanol to the 1# methanol storage cabinet V101. In addition, the accident collection pool of the fixed-frequency fuel supply pump group is also equipped with an accident fuel extraction pump, which can extract the leaked methanol to the 1# methanol storage cabinet.

[0053] (4) Volatile gas recovery: Due to the cabin temperature and high temperature weather, the methanol storage tank will produce a large amount of methanol volatile gas (commonly known as breathing gas). The volatile gas is introduced into the volatile gas recovery unit through an explosion-proof induced draft fan. After being processed through condensation, gas-liquid separation, water washing, adsorption and other processes, most of the methanol is recovered and the non-condensable gas is discharged in compliance with the standards. The methanol-water solution produced by water washing can be purified by distillation to separate methanol and water. The water can be recycled as washing water. The recovered low-temperature methanol is pumped to the top of the methanol storage tank for spraying to reduce the temperature and reduce the methanol breathing volume.

[0054] (5) Coil cooling: Since the respiration volume of methanol increases significantly with increasing temperature, the storage temperature of methanol must be controlled reasonably when storing it. The storage temperature of methanol can be controlled by setting up internal coils for cooling through refrigerant.

[0055] (6) Utility supply: Methanol storage tanks and volatile gas recovery processes require the use of auxiliary media such as refrigerant, steam, seawater, fresh water, and nitrogen. It is extremely necessary to design and match reasonable utilities.

[0056] The present invention is further characterized in that the 1# methanol storage tank and the 2# methanol storage tank are provided with peripheral sealed compartments.

[0057] The present invention is further characterized in that a sealed compartment is provided on the periphery of the methanol daily cabinet.

[0058] The present invention is further characterized in that the fixed-frequency fuel supply pump group is provided with an accident collection pool.

[0059] The present invention is further characterized in that the methanol variable frequency pump is provided with an accident collection pool.

[0060] The present invention is further characterized in that there are n methanol storage cabinets, where n is a natural number.

[0061] The present invention is further characterized in that there are n methanol daily cabinets, wherein n is a natural number.

[0062] The present invention is further characterized in that the volatile gas recovery unit adopts processes such as condensation, gas-liquid separation, water washing, purification and adsorption.

[0063] The present invention is further characterized in that the accident collection pool is independently provided with or shares the accident fuel extraction pump for extracting the leaked methanol to avoid the expansion of the leakage accident.

[0064] The present invention is further characterized in that the 1# methanol storage cabinet and the 2# methanol storage cabinet use cooling coils to control the methanol storage temperature.

[0065] The present invention is further characterized in that the 1# methanol storage tank and the 2# methanol storage tank adopt top spraying to recover low-temperature methanol, so as to further reduce the volatilization amount of methanol.

[0066] The present invention is further characterized in that the refrigerant can be an ethylene glycol solution, a lithium bromide solution or a more environmentally friendly refrigerant.

[0067] The specific working process of the present invention is as follows:

[0068] The methanol fuel from the 1# methanol storage tank V101 and the 2# methanol storage tank V102 of the storage unit is transported to the methanol daily tank V201 of the fuel supply unit through the fixed-frequency fuel supply pump group P101, and the methanol leaked from the fixed-frequency fuel supply pump group P101 is sent back to the 1# methanol storage tank V101 through the emergency fuel extraction pump P102.

[0069] The methanol fuel in the methanol daily cabinet V201 is transported to the methanol heater E201 through the methanol variable frequency pump P201, and is sent to the fuel valve group FVT01 after being heated by low-pressure steam. After switching, purging, discharging and flow regulation in the fuel valve group FVT01, the methanol fuel is measured by the methanol flowmeter FM201 and finally transported to the interface of the methanol fuel engine.

[0070] As a further improvement, the volatile gas from the 1# methanol storage cabinet and the 2# methanol storage cabinet of the storage unit is pressurized by the explosion-proof induced draft fan of the volatile gas recovery unit and then transported to the hot gas side of the volatile gas condenser, wherein most of the gaseous methanol is condensed into liquid methanol by the refrigerant, and the volatile gas mixed with gas and liquid phases is then transported to the gas-liquid separator, and the separated volatile gas enters the volatile gas water washing tower from the bottom, and is countercurrently contacted with the circulating water from the top of the tower, and most of the methanol is converted into methanol aqueous solution after being washed with water, and then discharged from the bottom of the tower into the methanol aqueous solution storage tank, while the volatile gas containing very little methanol is discharged from the top of the volatile gas water washing tower, and enters the activated carbon adsorption tank after the first-level methanol detector monitors the methanol concentration, and the volatile gas after activated carbon adsorption is then monitored by the second-level methanol detector for methanol concentration, and is discharged externally after being confirmed to meet the standard; the liquid methanol separated in the gas-liquid separator is transported to the methanol recovery tank through the methanol recovery pump tank, the liquid methanol in the methanol recovery tank is transported back to the 1# methanol storage cabinet and the 2# methanol storage cabinet of the storage unit through the methanol recovery circulation pump; the circulating water pump merges part of the methanol aqueous solution in the methanol aqueous solution storage tank with fresh water, and sends it to the volatile gas water washing tower for recycling, and sends another part of the methanol aqueous solution to the methanol purification tower for purification and recovery of the methanol aqueous solution; the reboiler at the bottom of the methanol purification tower reheats and evaporates the methanol aqueous solution, and the high-concentration gaseous methanol is sent out from the top of the tower, and enters the gas-liquid separator at the top of the tower after condensation by the condenser, and the condensed methanol is sent to the methanol recovery tank through the methanol recovery pump, and the non-condensable gaseous methanol is discharged from the top of the gas-liquid separator at the top of the tower and sent to the activated carbon adsorption tank, and finally the methanol concentration is monitored by the secondary methanol detector, and it is discharged to the outside after confirmation that it meets the standard; the high-temperature circulating water at the bottom of the methanol purification tower is sent to the cooler through the tower bottom water pump, and enters the methanol aqueous solution storage tank for recycling after cooling.

[0071] In this application, unless otherwise specified, all embodiments and preferred embodiments mentioned herein can be combined with each other to form a new technical solution.

[0072] In this application, unless otherwise specified, all technical features and preferred features mentioned herein can be combined with each other to form a new technical solution.

[0073] In the present application, unless otherwise specified, all steps mentioned herein may be performed sequentially or randomly, but are preferably performed sequentially.

[0074] In addition, those skilled in the art should understand that the above embodiments are only for detailed description rather than for limiting the scope of the present invention.

Claims

1. A marine methanol fuel storage and supply and volatile gas recovery system, connected to a methanol fuel engine, characterized in that: The system comprises: A fuel supply unit, connected to the methanol fuel engine and delivering methanol fuel to the interface of the methanol fuel engine, including a methanol daily cabinet, a methanol variable frequency pump, a methanol heater, a fuel valve group and a methanol flow meter; A storage unit connected to the fuel supply unit and supplying methanol fuel to the fuel supply unit, including a 1# methanol storage tank, a 2# methanol storage tank, a fixed-frequency fuel supply pump group and an emergency fuel extraction pump; A volatile gas recovery unit is connected to the storage unit, introduces volatile gas from the storage unit, and after treatment, returns the recovered methanol to the storage unit, including an explosion-proof induced draft fan, a volatile gas condenser, a gas-liquid separator, a methanol recovery pump, a volatile gas water washing tower, a primary methanol detector, an activated carbon adsorption tank, a secondary methanol detector, a methanol aqueous solution storage tank, a circulating water pump, a methanol purification tower, a reboiler, a condenser, a tower top gas-liquid separator, a methanol recovery tank, a recycled methanol circulating pump, a tower bottom water pump and a cooler; The utility unit is respectively connected to the fuel supply unit, the storage unit and the volatile gas recovery unit, and provides auxiliary media including refrigerant, steam, seawater, fresh water and nitrogen for the fuel supply unit, the storage unit and the volatile gas recovery unit.

2. The marine methanol fuel storage and supply and volatile gas recovery system according to claim 1 is characterized in that: The methanol fuel in the methanol daily cabinet is transported to the methanol heater through the methanol variable frequency pump, and is sent to the fuel valve group after being heated by low-pressure steam. After switching, purging, discharging and flow regulation in the fuel valve group, the methanol fuel is measured by the methanol flowmeter and finally transported to the interface of the methanol fuel engine.

3. The marine methanol fuel storage and supply and volatile gas recovery system according to claim 1 is characterized in that: The methanol fuel from the 1# methanol storage tank and the 2# methanol storage tank of the storage unit is transported to the methanol daily cabinet of the fuel supply unit through the fixed-frequency fuel supply pump group, and the methanol leaked in the fixed-frequency fuel supply pump group is sent back to the 1# methanol storage tank through the accident fuel extraction pump.

4. The marine methanol fuel storage and supply and volatile gas recovery system according to claim 1 is characterized in that: The volatile gas from the 1# methanol storage cabinet and the 2# methanol storage cabinet of the storage unit is pressurized by the explosion-proof induced draft fan of the volatile gas recovery unit and then transported to the hot gas side of the volatile gas condenser, wherein most of the gaseous methanol is condensed into liquid methanol by the refrigerant, and the volatile gas mixed with gas and liquid phases is then transported to the gas-liquid separator, and the separated volatile gas enters the volatile gas water washing tower from the bottom, and countercurrently contacts with the circulating water from the top of the tower, and most of the methanol is converted into methanol aqueous solution after being washed with water, and then discharged from the bottom of the tower into the methanol aqueous solution storage tank, while the volatile gas containing very small amount of methanol is discharged from the top of the volatile gas water washing tower, and enters the activated carbon adsorption tank after the first-level methanol detector monitors the methanol concentration, and the volatile gas after activated carbon adsorption is then monitored by the second-level methanol detector for methanol concentration, and is discharged externally after being confirmed to meet the standard; the liquid methanol separated in the gas-liquid separator is transported to the methanol recovery tank by the methanol recovery pump, and the methanol The liquid methanol in the alcohol recovery tank is transported back to the 1# methanol storage tank and the 2# methanol storage tank of the storage unit through the methanol recovery circulation pump; the circulating water pump combines part of the methanol aqueous solution in the methanol aqueous solution storage tank with fresh water, and sends it to the volatile gas water washing tower for recycling, and sends another part of the methanol aqueous solution to the methanol purification tower for purification and recovery of the methanol aqueous solution; the reboiler at the bottom of the methanol purification tower reheats and evaporates the methanol aqueous solution, and the high-concentration gaseous methanol is sent out from the top of the tower, and enters the gas-liquid separator at the top of the tower after condensation by the condenser, and the condensed methanol is sent to the methanol recovery tank through the methanol recovery pump, and the non-condensable gaseous methanol is discharged from the top of the gas-liquid separator at the top of the tower and sent to the activated carbon adsorption tank, and finally the methanol concentration is monitored by the secondary methanol detector, and is discharged to the outside after confirmation that it meets the standard; the high-temperature circulating water at the bottom of the methanol purification tower is sent to the cooler through the tower bottom water pump, and enters the methanol aqueous solution storage tank for recycling after cooling.

5. The marine methanol fuel storage and supply and volatile gas recovery system according to claim 1 is characterized in that: The peripheries of the methanol daily cabinet, the 1# methanol storage cabinet and the 2# methanol storage cabinet are provided with sealed compartments.

6. The marine methanol fuel storage and supply and volatile gas recovery system according to claim 5 is characterized in that: The storage unit is provided with n methanol storage cabinets and n sealed compartments, wherein n is a natural number.

7. The marine methanol fuel storage, supply and volatile gas recovery system according to claim 1 is characterized in that: An accident collection pool is arranged around the methanol variable frequency pump and the fixed frequency fuel supply pump group.

8. The marine methanol fuel storage, supply and volatile gas recovery system according to claim 7 is characterized in that: The emergency fuel extraction pump is arranged in the emergency collection pool of the fixed frequency fuel supply pump group.

9. The marine methanol fuel storage and supply and volatile gas recovery system according to claim 1, characterized in that: The volatile gas recovery unit adopts condensation recovery, gas-liquid separation, water washing, purification and adsorption processes to treat the volatile gas.

10. The marine methanol fuel storage and supply and volatile gas recovery system according to claim 1, characterized in that: The 1# methanol storage cabinet and the 2# methanol storage cabinet use internal coils to adjust the methanol storage temperature via refrigerant to suppress the volatilization of methanol.

11. The marine methanol fuel storage and supply and volatile gas recovery system according to claim 1, characterized in that: The tops of the 1# methanol storage tank and the 2# methanol storage tank are sprayed to cool the recovered low-temperature methanol, so as to further reduce the methanol volatilization amount.

12. The marine methanol fuel storage and supply and volatile gas recovery system according to claim 1, characterized in that: The refrigerant is ethylene glycol solution or lithium bromide solution.

13. The marine methanol fuel storage and supply and volatile gas recovery system according to claim 1, characterized in that: The system described adopts the following process measures: 1) Delivery of daily methanol: the storage unit is used as a total methanol fuel storage cabinet, and the fixed-frequency fuel supply pump group delivers methanol to the methanol daily cabinet of the fuel supply unit; 2) Supply of methanol fuel engine fuel: When the engine is switched into the methanol combustion working mode, the methanol variable frequency pump is started to deliver the methanol in the methanol daily cabinet to the methanol heater, and the heated methanol is continuously delivered to the fuel valve group, and after switching and adjustment, it is delivered to the methanol flowmeter for metering, and then delivered to the interface of the methanol fuel engine, so as to supply the corresponding methanol fuel according to the engine load; 3) Collection of accidental methanol: Sealed compartments are set in the 1# methanol storage cabinet, 2# methanol storage cabinet and methanol daily cabinet to prevent leakage accidents from spilling out, and accident collection pools are set in the fixed-frequency fuel supply pump group and the methanol variable-frequency pump, wherein the accident collection pools of the methanol daily cabinet, the methanol variable-frequency pump and the fixed-frequency fuel supply pump group are equipped with accident fuel extraction pumps to extract the leaked methanol to the 1# methanol storage cabinet; 4) Recovery of volatile gas: The volatile gas is introduced into the volatile gas recovery unit through the explosion-proof induced draft fan, and most of the methanol is recovered and discharged in compliance with the standards after condensation, gas-liquid separation, water washing, and adsorption treatment. The methanol-water solution washed with water is purified by distillation to separate methanol and water, and the water is recycled as washing water. The liquid methanol is pumped to the 1# methanol storage tank and the 2# methanol storage tank for recovery, and the top is sprayed for cooling to reduce the methanol respiration volume; 5) Coil cooling: The methanol storage temperature is controlled by cooling the internal coil with refrigerant to suppress the methanol respiration; 6) Utility supply: A reasonably matched utility unit is set up to provide a stable auxiliary medium supply for the refrigerant, steam, seawater, fresh water and nitrogen used in the marine methanol fuel storage and supply and volatile gas recovery system.

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