JP2019531966A - Marine fuel gas supply system and marine fuel gas supply method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a marine fuel gas supply system. A marine fuel gas supply system vaporizes liquefied natural gas and supplies it to an engine; cooling water discharged after cooling the engine and fluid used as a heat medium in the vaporizer A first heater that heat-exchanges and heats a fluid used as a heat medium in the vaporizer; and a part or all of a heat source of cooling water that has passed through the first heater after being discharged from the engine The liquefied natural gas by exchanging heat between the fluid heated by the first heater and the liquefied natural gas. Vaporize. [Selection] Figure 1

Description

  The present invention relates to a system for supplying fuel gas to a marine engine by utilizing the amount of heat of engine cooling water and a marine fuel gas supply method.

  Liquefied natural gas is a colorless and transparent liquid obtained by cooling and liquefying natural gas mainly composed of methane to about −163 ° C., and its volume is about 1/600 compared to natural gas. . Therefore, when natural gas is liquefied and transferred, very efficient transfer is possible. Generally, after natural gas is liquefied and stored in a storage tank in the form of liquefied natural gas, the liquefied natural gas is transported by ship.

  On the other hand, among engines used for ships, engines using natural gas as fuel include gas fuel engines such as DFDE, ME-GI engine, and X-DF engine. DFDE is a 4-stroke engine used for power generation. An Otto Cycle in which natural gas having a relatively low pressure of about 6.5 bar is injected into the combustion air inlet and the piston is compressed while ascending is employed. The ME-GI engine is a two-stroke engine used for propulsion. The diesel cycle (Diesel Cycle) is used, in which high-pressure natural gas of about 300 bar is directly injected into the combustion chamber near the top dead center of the piston. The X-DF engine is a two-stroke engine used for propulsion. Otto cycle is adopted using medium pressure natural gas of about 16 bar as fuel.

  In order to supply natural gas as an engine to the fuel, the liquefied natural gas stored in the storage tank may be vaporized and then supplied to the engine, and a heat source is required to vaporize the liquefied natural gas. It is. As a heat source for vaporizing liquefied natural gas, a technology using engine cooling water has been developed.

  In general, the cooling water after cooling the engine is controlled to have a predetermined temperature, and as an example, the cooling water after cooling the ME-GI engine is controlled to be about 85 ° C. Here, the higher the engine load is, the more heat is generated in the engine. Therefore, the cooling water needs to cool more heat. On the other hand, when the engine load is low, the amount of heat generated from the engine decreases. Cooling water only needs to cool a small amount of heat. Further, since there is a risk of low-temperature corrosion of the engine, the engine is not cooled to a temperature lower than a predetermined temperature. Therefore, as the engine load decreases, the amount of heat obtained from the cooling water decreases.

  The present invention relates to a marine fuel gas supply system in which various devices are efficiently arranged in order to appropriately distribute a heat source of cooling water that fluctuates according to an engine load, and to a marine vessel that appropriately distributes a heat source of cooling water. An object is to provide a fuel gas supply method.

  In order to achieve the above-described object, in one embodiment of the present invention, a carburetor that vaporizes liquefied natural gas and supplies the liquefied natural gas to the engine; cooling water discharged after the engine is cooled; A first heater that heat-exchanges the fluid used as the vaporizer and heats the fluid used in the vaporizer; and a heat source that the cooling water that has passed through the first heater after being discharged from the engine A fresh water generator that heats seawater to obtain fresh water using a part or all of the water, and the vaporizer exchanges heat between the fluid heated by the first heater and the liquefied natural gas. A marine fuel gas supply system is provided, wherein the liquefied natural gas is vaporized.

  Preferably, the marine fuel gas supply system may include an expansion tank that absorbs a volume change generated while the cooling water expands or contracts.

  Preferably, the engine is arranged in an engine room, and the expansion tank can be arranged 20 m to 25 m above the engine room.

  Preferably, the first heater is disposed at a position higher than the expansion tank.

  Preferably, the marine fuel gas supply system may further include a second heater that heats the cooling water discharged from the water generator and supplied to the engine.

  Preferably, the cooling water discharged from the engine branches into two flows, one being sent to the first heater, the other bypassing the first heater, and cooling bypassing the first heater The marine fuel gas supply system may further include a first three-way valve installed at a point where water and cooling water that has passed through the first heater merge.

  Preferably, the first three-way valve can be installed at a position lower than the expansion tank.

  The marine fuel gas supply system may further include a cooler that lowers the temperature of the cooling water that has passed through the first heater and the fresh water generator after being discharged from the engine.

  Preferably, the marine fuel gas supply system further includes a third temperature adjustment sensor installed on a line through which the cooling water discharged from the cooler is supplied to the engine to adjust the temperature of the cooling water. The set value of the third temperature control sensor decreases as the engine load increases.

  Preferably, the heat source obtained by cooling water while cooling the engine is used most preferentially in the first heater, and the rest is used in the water generator, and remains even when used in the water generator. The heat source is cooled by the cooler.

  Preferably, the marine fuel gas supply system further includes a storage tank for storing the remaining cooling water that has not been sent to the first heater among the cooling water used to cool the engine. Can do.

  Preferably, the marine fuel gas supply system may further include first pressurizing means installed on a line for supplying cooling water discharged from the storage tank to the expansion tank, and The pressure means operates when the water level of the storage tank becomes equal to or higher than a predetermined height, or when the water level of the expansion tank becomes equal to or lower than a predetermined height.

  Preferably, the marine fuel gas supply system may further include a second pressurizing unit that pressurizes cooling water discharged from the water generator and supplies the pressurized water to the engine.

  Preferably, the marine fuel gas supply system further includes a first valve that prevents a reverse flow of cooling water supplied from the engine to the first heater when the second pressurizing unit stops. it can.

  Preferably, the vaporizer, the first heater, the fresh water generator, and the second pressurizing unit are connected in series so that the cooling water can be circulated only by the second pressurizing unit.

  Preferably, the marine fuel gas supply system may further include a third pressurizing unit installed on a line through which cooling water discharged from the engine is supplied to the first heater.

  Preferably, the load of the water generator is A, where the load of the engine is A, the maximum amount of heat transferred to the fluid used in the vaporizer is x, the load of the water generator is B, and the engine is cooled. However, when the maximum amount of heat obtained by the cooling water is y and the amount of heat required when the load of the water generator is 100% is z, it can be expressed as B = (y−x) A / z.

  Preferably, the marine fuel gas supply system is installed on a line through which cooling water is supplied from the engine to the first heater to adjust the temperature of the cooling water to be constant; or A second temperature adjustment sensor installed on a line through which cooling water discharged from the water generator is supplied to the engine to adjust the temperature of the cooling water; (2) The set value of the temperature adjustment sensor decreases as the engine load increases.

  Preferably, the marine fuel gas supply system is installed on a line through which the cooling water that has passed through the first heater after being discharged from the engine is sent to the water generator, and the air contained in the cooling water is discharged. An air separator to be removed can be further provided.

  Preferably, the marine fuel gas supply system may further include an air discharge tank that discharges air contained in cooling water sent from the water generator to the engine.

  Preferably, a part or all of the piping through which the cooling water flows may be heat-insulated.

  In order to achieve the above-mentioned object, in another embodiment of the present invention, 1) the cooling medium discharged after cooling the engine and the fluid used as the heating medium are subjected to heat exchange to first heat the heating medium. 2) Step of vaporizing liquefied natural gas by exchanging heat between the fluid heated by the heat exchange in step 1) and liquefied natural gas; 3) Vaporizing in step 2) 4) supplying the engine with natural gas, and 4) using a part or all of the heat source of the cooling water used for heat exchange of the fluid in the step 1). A marine fuel gas supply method is provided, comprising: heating seawater to obtain fresh water.

  Preferably, the marine fuel gas supply method may further include 5) heating the cooling water used in the fresh water generator in the step 4).

  Preferably, in the step 5), when the engine is not operated, the cooling water is heated to a predetermined temperature or higher that prevents low temperature corrosion of the engine.

  Preferably, in the step of 5), in the step of 4), when the water generator is operated 100%, the temperature of the cooling water is lower than the temperature that prevents low temperature corrosion of the engine. After the engine is operated 100%, the cooling water is heated to a predetermined temperature or higher that prevents low temperature corrosion of the engine.

  Preferably, the marine fuel gas supply method may further include 5) a step of pressurizing the cooling water discharged from the water generator with a second pressurizing unit and supplying the pressurized water to the engine.

  Preferably, the cooling water discharged from the engine is branched into two flows, one is sent to the first heater, the other bypasses the first heater and bypasses the first heater. A first three-way valve can be installed at a point where the cooling water and the cooling water that has passed through the first heater merge.

  Preferably, when the second pressurizing means stops, in the first three-way valve, the valve in the direction of the first heater is closed and the other valves are kept open.

  Preferably, when the second pressurizing means stops, the algorithm is configured to automatically close the valve in the first heater direction by the control panel in the first three-way valve.

  In order to achieve the above-described object, in another embodiment of the present invention, an engine is disposed in an engine room, and an expansion tank that absorbs a volume change generated while cooling water expands or contracts is provided in the engine room. Disposed above 20m to 25m, disposed at a position higher than the first heater expansion tank for heating the fluid used as a heat medium for vaporizing the liquefied natural gas, and the cooling water bypassing the first heater and the first A marine fuel gas supply system is provided in which a first three-way valve installed at a point where cooling water having passed through one heater joins is installed at a position lower than an expansion tank.

  In order to achieve the above-described object, in yet another embodiment of the present invention, the engine load is A, the maximum amount of heat transferred to the fluid used as a heat medium in the carburetor is x, and When the load is B, the maximum amount of heat that the cooling water obtains while cooling the engine is y, and the amount of heat required when the load of the fresh water generator is 100% is z, the engine is expressed by the equation: Ax + Bz = Ay A marine fuel gas supply method is provided in which the amount of heat obtained by the cooling water is distributed to the vaporizer and the water generator while cooling the water.

  The marine fuel gas supply system and marine fuel gas supply method according to the present invention adjust the load of the water generator and cool the engine based on a mathematical expression representing the correlation between the load of the engine and the load of the water generator. The amount of heat obtained by the cooling water can be appropriately distributed to the vaporizer and the water generator.

  Since the marine fuel gas supply system and marine fuel gas supply method of the present invention include the first heater and the vaporizer, the capacity of the cooler is reduced, and the energy required for driving the cooler can be reduced. it can.

  Since the marine fuel gas supply system and marine fuel gas supply method of the present invention store and reuse excess cooling water in a storage tank, it is possible to minimize the consumption of cooling water that requires chemical treatment. it can.

  According to the marine fuel gas supply system and marine fuel gas supply method of the present invention, the devices installed on the line through which the cooling water circulates are connected in series, and the second addition is possible without installing additional pressurizing means. Cooling water can be circulated only by the pressure of the pressure means.

  According to the marine fuel gas supply system and marine fuel gas supply method of the present invention, even when the engine load is low, the water heater is operated at 100%, and then the low temperature corrosion of the engine is performed by the second heater. Therefore, the system can be operated more flexibly because it is only necessary to heat to a predetermined temperature that can prevent the above.

  In the marine fuel gas supply system and marine fuel gas supply method of the present invention, the first heater can be installed above the expansion tank, and can be prepared for the adverse effects when the second pressurizing means stops. .

  Further, in the marine fuel gas supply system and marine fuel gas supply method of the present invention, it is possible to automatically and efficiently control each device by the control panel, particularly when the second pressurizing means fails. Can prepare for evil.

1 is a schematic diagram of a marine fuel gas supply system according to a first embodiment of the present invention. The schematic of the fuel gas supply system for ships concerning a 2nd embodiment of the present invention.

  Hereinafter, the configuration and operation of an embodiment of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments can be changed and modified in various forms, and the scope of the present invention is not limited by the following embodiments.

  FIG. 1 is a schematic view of a marine fuel gas supply system according to a first embodiment of the present invention.

  Referring to FIG. 1, the marine fuel gas supply system of the present embodiment includes a first heater (110), a vaporizer (180), and a water generator (120).

  Engines (E) that are supplied with fuel by the marine fuel gas supply system of this embodiment include ME-GI engines, X-DF engines, and DF engines that use natural gas as fuel. The marine fuel gas supply system can be applied to other combustion apparatuses that use natural gas as a fuel, such as a gas turbine. However, it is preferable to apply the marine fuel gas supply system of the present embodiment to an ME-GI engine used as a main propulsion engine. The engine (E) is disposed in the engine room.

  The first heater (110) exchanges heat between the cooling water (L10 line) discharged after cooling the engine (E) and the fluid (L3 line) used as a heat medium in the vaporizer (180). That is, the first heater (110) supplies a part of the heat source obtained from the cooling water while cooling the engine (E) to the fluid (L3 line) used as a heat medium in the vaporizer (180). The fluid (L3 line) used as a heat medium in the vaporizer (180) is heated.

  On the line (L10) through which cooling water is supplied from the engine (E) to the first heater (110), the temperature of the cooling water discharged from the engine (E) and supplied to the first heater (110) A first temperature control sensor (210) for adjusting the temperature is installed. The first temperature adjustment sensor (210) adjusts the temperature of the cooling water discharged from the engine (E) to about 85 ° C.

  In the marine fuel gas supply system of the present embodiment, the temperature of the cooling water discharged from the engine (E) is adjusted to be constant at about 85 ° C. Since the heat generated in the engine (E) increases as the load on the engine (E) increases, the temperature of the cooling water supplied to the engine (E) is changed according to the load on the engine (E). Moreover, in order to prevent low temperature corrosion of an engine (E), the temperature of the cooling water supplied to an engine (E) is made high, so that the load of an engine (E) becomes low.

  The vaporizer (180) heat-exchanges the heat medium (L4 line) heated by the first heater (110) and the liquefied natural gas, and vaporizes the liquefied natural gas. That is, the vaporizer (180) uses a part of the heat source obtained by the cooling water while cooling the engine (E) to vaporize the liquefied natural gas through the heat medium. Natural gas (L1 line) vaporized by the vaporizer (180) is supplied to the engine (E) and used as fuel. Examples of the fluid used as the heat medium in the vaporizer (180) include glycol water.

  The water generator (120) heats seawater using part or all of the heat source of the cooling water (L20 line) that has passed through the first heater (110) after being discharged from the engine (E). And get fresh water.

  The amount of heat that the cooling water obtains while cooling the engine (E) is proportional to the load of the engine (E). The higher the engine (E) load, the greater the amount of fuel required, so the amount of liquefied natural gas vaporized by the carburetor (180) increases as the engine (E) load increases. The amount of heat transferred from the heater (110) to the fluid used as a heat medium in the vaporizer (180) is also proportional to the load on the engine (E).

  Therefore, the load on the engine (E) is A, the maximum amount of heat transferred to the fluid used as the heat medium in the vaporizer (180) is x, the load on the water generator (120) is B, and the engine (E) is cooled. On the other hand, when the maximum amount of heat obtained by the cooling water is y and the amount of heat required when the load of the water generator (120) is 100% is z, the following equation is established.

  Ax + Bz = Ay

  Therefore, the load of the fresh water generator (120) is expressed by B = (y−x) A / z, and the load of the fresh water generator (120) is adjusted based on this formula to cool the engine (E). The amount of heat obtained by the cooling water can be appropriately distributed to the vaporizer (180) and the water generator (120).

  In the marine fuel gas supply system of this embodiment, the heat source obtained while cooling water cools the engine (E) is preferentially used by the first heater (110), and the rest is the fresh water generator (120). Used in.

  The cooling water (L10 line) discharged from the engine (E) branches into two flows, one (L10 line) is sent to the first heater (110), and the other (L12 line) is the first heater (L12 line). 110). The cooling water (L12 line) bypassing the first heater (110) and the cooling water (L20 line) passing through the first heater (110) merge and are sent to the fresh water generator (120). A first three-way valve (810) is installed at a point where the coolant (L12 line) bypassing the heater (110) and the coolant (L20 line) passing through the first heater (110) merge. . In the marine fuel gas supply system of the present embodiment, the amount of cooling water sent to the first heater (110) is adjusted by adjusting the opening of the first three-way valve (810), and finally the cooling water. The amount of heat transferred from the first to the first heater (110) can be adjusted.

  A temperature sensor (not shown) can be installed on the line (L4) through which the heat medium is sent from the first heater (110) to the vaporizer (180), and the temperature sensor installed on the L4 line is The opening degree of the first three-way valve (810) can be adjusted based on the sensed temperature value. Since the temperature of the heat medium supplied along the L4 line increases as the amount of liquefied natural gas vaporized by the vaporizer (180) increases, the temperature of the heat medium supplied along the L4 line can be adjusted. The amount of liquefied natural gas to be vaporized can be adjusted, the amount of cooling water sent to the first heater (110) by the first three-way valve (810) is adjusted, and the heat supplied along the L4 line Adjust the temperature of the medium.

  Further, the marine fuel gas supply system of the present embodiment can be operated so that the temperature of the heat medium flowing through the L4 line is maintained constant. Since the temperature of the fluid (L3 line) discharged after being used as a heat medium for vaporizing the liquefied natural gas in the vaporizer (180) is lowered, it is supplied to the first heater (110) along the L3 line. The opening degree of the first three-way valve (810) is adjusted in order to heat the fluid to the set temperature.

  On the line (L4) through which the heat medium is sent from the first heater (110) to the vaporizer (180), a second valve (720) for adjusting the flow rate and opening / closing of the fluid is installed.

  The marine fuel gas supply system of the present embodiment is installed on a line (L20) through which the cooling water that has been discharged from the engine (E) and passed through the first heater (110) is sent to the fresh water generator (120). The air separator (330) is further provided. The air separator (330) is provided in the marine fuel gas supply system of this embodiment by removing air contained in the cooling water supplied from the first heater (110) to the water generator (120). Prevent the failure of various devices.

  On the other hand, the cooling water (L20 line) that has passed through the first heater (110) after being discharged from the engine (E) branches into two flows, and one (L20 line) is sent to the water generator (120). And the other (L22 line) bypasses the fresh water generator (120). The cooling water (L22 line) bypassing the water generator (120) and the cooling water (L30 line) passing through the water generator (120) merge and are sent to the re-engine (E), where the water generator (120 The second three-way valve (820) is installed at a point where the cooling water (L22 line) bypassing the water) and the cooling water (L30 line) that has passed through the water generator (120) merge. In the marine fuel gas supply system of the present embodiment, the opening of the second three-way valve (820) is adjusted to adjust the amount of cooling water sent to the water generator (120), and finally the cooling water. Adjusts the amount of heat transferred to the fresh water generator (120).

  A second temperature adjustment sensor (220) for adjusting the temperature of the cooling water is installed on a line (L30) through which the cooling water discharged from the water generator (120) is supplied to the engine (E). The set value of the second temperature control sensor (220) decreases as the load on the engine (E) increases.

  The marine fuel gas supply system of this embodiment includes a cooler (130) that lowers the temperature of cooling water that has passed through the first heater (110) and the water generator (120) after being discharged from the engine (E). Is further provided. The cooler (130) has a sufficient temperature even after the cooling water that has obtained heat while cooling the engine (E) supplies a part of the heat to the first heater (110) and the water generator (120). If not, the cooling water temperature is lowered so that the cooling water is cooled to the temperature required for the engine (E).

  In the marine fuel gas supply system of this embodiment, the cooling water (L30 line) discharged from the water generator (120) branches into two flows, and one (L30 line) is sent to the cooler (130). The other (L32 line) bypasses the cooler (130). The cooling water (L32 line) bypassing the cooler (130) and the cooling water (L40 line) passing through the cooler (130) merge and are sent to the engine (E), bypassing the cooler (130). A third three-way valve (830) is installed at a point where the cooling water (L32 line) and the cooling water (L40 line) that has passed through the cooler (130) merge. The amount of cooling water sent to the cooler (130) is adjusted by adjusting the opening of the third three-way valve (830), and finally the degree to which the cooling water is cooled by the cooler (130) is adjusted. To do.

  Conventionally, the heat source of the cooling water is not used for heating the liquefied natural gas, and the cooling water is cooled by the cooler (130) and then supplied to the engine (E). Then, the first heater (110) and the vaporizer (180) are provided, and the cooling water heat source is used for heating the liquefied natural gas and then cooled by the cooler (130) only when necessary. The capacity of the cooler (130) is reduced, and the energy required for driving the cooler (130) can be reduced.

  In the marine fuel gas supply system of the present embodiment, the heat source obtained while cooling water cools the engine (E) is preferentially used by the first heater (110), and the rest is the fresh water generator (120). The heat source that is used and remains even if it is used in the water generator (120) is cooled by the cooler (130).

  In the marine fuel gas supply system of the present embodiment, the temperature of the cooling water is adjusted on the line (L40) through which the cooling water discharged from the cooler (130) is supplied to the engine (E). A temperature control sensor (230) is installed. The set value of the third temperature control sensor (230) decreases as the load on the engine (E) increases.

  The marine fuel gas supply system of the present embodiment may further include at least one of a storage tank (160), an expansion tank (170), and an air discharge tank (140).

  The storage tank (160) stores the remaining cooling water that has not been sent to the first heater (110) among the cooling water used for cooling the engine (E). A part of the cooling water stored in the storage tank (160) can be sent to the expansion tank (170) (L50 line). Excess cooling water can be stored in the storage tank (160) and reused, so that consumption of cooling water that requires chemical treatment can be minimized.

  The expansion tank (170) absorbs a volume change generated while the cooling water expands or contracts to increase the stability of the system and plays a role of applying a pressure necessary for circulating the cooling water. In addition to the cooling water from the storage tank (160), the air discharged from the air discharge tank (140) is supplied to the expansion tank (170). When the pressure inside the expansion tank (170) is too high, the internal gas in the expansion tank (170) is discharged along the gas discharge line (L2).

  Such an expansion tank (170) can be disposed about 20 m to 25 m above the engine room where the engine (E) is disposed. When the height of the expansion tank (170) exceeds 25 m, the pressure of the cooling water supplied to the engine (E) exceeds the required pressure. The height of the expansion tank (170) varies depending on the cooling water temperature required by the engine (E). In addition, when the pressure of the cooling water is lowered, bubbles may be generated, and the pressure at which the bubbles are generated differs depending on the temperature of the cooling water, so that the cooling water depends on the temperature of the cooling water required by the engine (E). The height of the expansion tank (170) is determined so that the pressure is such that no bubbles are generated.

  The air discharge tank (140) discharges air contained in the cooling water sent from the water generator (120) to the engine (E) to the expansion tank (170), and changes rapidly according to the temperature change of the cooling water. It plays a role in mitigating the effects of volume changes. Cooling water sent from the water generator (120) to the engine (E) is temporarily stored in the air discharge tank (140) and sent to the engine (E).

  Further, the marine fuel gas supply system of the present embodiment includes a first pressurizing means installed on a line (L50) for supplying the cooling water discharged from the storage tank (160) to the expansion tank (170). (410) may further be provided.

  The first pressurizing means (410) cooperates with the first water level adjusting device (310) for adjusting the water level of the storage tank (160) and the second water level adjusting device (320) for adjusting the water level of the expansion tank (170). Can work. That is, the first pressurizing means (410) is activated when the water level of the storage tank (160) is equal to or higher than a predetermined height, or when the water level of the expansion tank (170) is lower than a predetermined height. The cooling water inside (160) is sent to the expansion tank (170).

  Further, the marine fuel gas supply system of the present embodiment includes a second pressurizing means (420) that pressurizes the cooling water discharged from the water generator (120) and supplies it to the engine (E), or the engine (E ) May be further provided with one or both of the first valve (710) installed on the line (L10) through which the cooling water is supplied to the first heater (110) to prevent the backflow of the cooling water. .

  A plurality of the second pressurizing means (420) may be connected in parallel. The second pressurizing means (420) can pressurize the cooling water to about 3 bar, and satisfy both the pressure for circulating the cooling water and the pressure required for the engine (E). Pressurize.

  When the second pressurizing means (420) is provided, the engine (E) can circulate the cooling water only by the pressure of the second pressurizing means (420) without installing any additional pressurizing means. The devices installed on the circulation line through which the discharged cooling water is supplied to the engine (E) again are preferably connected in series.

  The first valve (710) prevents the backflow of the cooling water supplied from the engine (E) to the first heater (110) when the second pressurizing means (420) is stopped. To do.

  The marine fuel gas supply system of the present embodiment may further include a second heater (150) that heats the cooling water that is discharged from the water generator (120) and supplied to the engine (E). The second heater (150) heats the cooling water by exchanging heat between the steam and the cooling water. A third valve (730) can be installed on the steam supply line, and the amount of steam is adjusted by adjusting the opening of the third valve (730), and finally the cooling water is heated. Adjust the degree.

  Further, the second heater (150) heats the cooling water to a predetermined temperature or higher in order to prevent low temperature corrosion of the engine (E) when the ship is anchored and the engine (E) is not operated. E) to supply. When the second heater (150) is operated, the cooler (130) is generally not operated.

  When the marine fuel gas supply system of the present embodiment includes the second heater (150), the load of the engine (E) is low, so that the water generator (120) can be used even when there are few heat sources of cooling water that can be used. It can be operated at 100%. Conventionally, when the load on the engine (E) is low, if the water generator (120) is operated 100%, the temperature of the cooling water supplied to the engine (E) becomes excessively low and the engine (E) Since it becomes impossible to prevent low-temperature corrosion, it was impossible to operate the fresh water generator (120) at 100%. However, in the marine fuel gas supply system of the present embodiment, even when the load of the engine (E) is low, the water generator (120) is operated at 100%, and then the cooling water is cooled by the second heater (150). Can be heated to a predetermined temperature at which low temperature corrosion of the engine (E) can be prevented, so that the system can be operated more flexibly.

  When the second heater (150) is provided, the cooling water discharged from the water generator (120) branches into two flows, and one (L60 line) is sent to the second heater (150). The other (L62 line) bypasses the second heater (150). The cooling water (L62 line) bypassing the second heater (150) and the cooling water (L60 line) passing through the second heater (150) merge and are sent to the engine (E), where the second heater A fourth valve (740) can be installed on the line (L62) through which the cooling water bypassing (150) flows. In the marine fuel gas supply system of this embodiment, the amount of cooling water sent to the second heater (150) is adjusted by adjusting the opening of the fourth valve (740), and finally the second valve (740). The degree to which the cooling water is heated by the heater (150) can be adjusted.

  When the marine fuel gas supply system of this embodiment includes all of the cooler (130), the air discharge tank (140), the second pressurizing means (420), and the second heater (150), The cooler (130) is installed at the rear stage of the machine (120), the air discharge tank (140) is installed at the rear stage of the cooler (130), and the second pressurizing means (420) is installed at the rear stage of the air discharge tank (140). ), The second heater (150) is installed downstream of the second pressurizing means (420), and the engine (E) is installed downstream of the second heater (150).

  The marine fuel gas supply system of this embodiment includes a first three-way valve (810), a second three-way valve (820), a third three-way valve (830), a third valve (730), and a first temperature control sensor (210 ), The second temperature control sensor (220), or the third temperature control sensor (230), the first three-way valve (810), the second three-way valve (820), the third The three-way valve (830), the third valve (730), the first temperature adjustment sensor (210), the second temperature adjustment sensor (220), and the third temperature adjustment sensor (230) are respectively controlled by the control panel (C). Operation is controlled.

  The control panel (C) comprehensively analyzes the operation status of the system based on information collected by each connected device and the state of each device, and controls each device.

  In the above-described marine fuel gas supply system of the present embodiment, in order to make the best use of the heat source of the cooling water discharged from the engine (E) without losing it, the piping through which the cooling water flows (in FIG. (Indicated by a heavy line) can be heat-insulated.

  FIG. 2 is a schematic view of a marine fuel gas supply system according to a second embodiment of the present invention.

  In the marine fuel gas supply system shown in FIG. 2, the first heater (110) is disposed at a position higher than the expansion tank (170) as compared to the marine fuel gas supply system shown in FIG. And the third pressurizing means (190) is further provided, and the difference will be mainly described below. Detailed description of the same members as those of the marine fuel gas supply system of the first embodiment described above will be omitted.

  Referring to FIG. 2, the marine fuel gas supply system of the present embodiment is similar to the marine fuel gas supply system of the first embodiment in that the first heater (110), vaporizer (180), and A water machine (120) is provided.

  As in the first embodiment, the engine (E) supplied with fuel by the marine fuel gas supply system according to the present embodiment uses an ME-GI engine, an X-DF engine, and a DF that use natural gas as fuel. There is an engine or the like, and the marine fuel gas supply system of the present embodiment can be applied to other combustion apparatuses that use natural gas as a fuel, such as a gas turbine, as in the first embodiment. However, it is preferable that the marine fuel gas supply system of this embodiment is applied to the ME-GI engine used as the main propulsion engine, as in the first embodiment. The engine (E) is arranged in the engine room as in the first embodiment.

  As in the first embodiment, the first heater (110) is a fluid (L3) used as a heat medium in the cooling water (L10 line) discharged after cooling the engine (E) and the vaporizer (180). Line). That is, as in the first embodiment, the first heater (110) uses a part of the heat source obtained by the cooling water while cooling the engine (E) as a heat medium in the vaporizer (180). The fluid (L3 line) is supplied to the fluid (L3 line) and heated as a heat medium in the vaporizer (180).

  On the line (L10) through which the cooling water is supplied from the engine (E) to the first heater (110), the first heater (110) is discharged from the engine (E) as in the first embodiment. The 1st temperature control sensor (210) which adjusts the temperature of the cooling water supplied to is installed. The 1st temperature control sensor (210) adjusts the temperature of the cooling water discharged | emitted from the engine (E) to about 85 degreeC similarly to 1st Embodiment.

  In the marine fuel gas supply system of the present embodiment, the temperature of the cooling water discharged from the engine (E) is adjusted to be constant at about 85 ° C., as in the first embodiment. The temperature of the cooling water supplied to the engine (E) is changed according to the load of the engine (E). That is, as the load on the engine (E) becomes lower, the temperature of the cooling water supplied to the engine (E) is increased in order to prevent low temperature corrosion of the engine (E).

  Similarly to the first embodiment, the vaporizer (180) exchanges heat between the heat medium (L4 line) heated by the first heater (110) and the liquefied natural gas to vaporize the liquefied natural gas. That is, the vaporizer (180) vaporizes the liquefied natural gas by using a heat medium as a part of the heat source obtained by the cooling water while cooling the engine (E), as in the first embodiment. Used for. The natural gas (L1 line) vaporized by the vaporizer (180) is supplied to the engine (E) and used as fuel, as in the first embodiment. The fluid used as a heat medium in the vaporizer (180) includes glycol water as in the first embodiment.

  As in the first embodiment, the water generator (120) is a part or all of the heat source of the cooling water (L20 line) that has passed through the first heater (110) after being discharged from the engine (E). Utilizing it, seawater is heated to obtain fresh water.

  While the load of the engine (E) is A, the maximum amount of heat transferred to the fluid used as a heat medium in the vaporizer (180) is x, the load of the water generator (120) is B, and the engine (E) is being cooled Assuming that the maximum amount of heat obtained by the cooling water is y and the amount of heat required when the load of the water generator (120) is 100% is z, the following equation is established as in the first embodiment.

  Ax + Bz = Ay

  Therefore, the load of the fresh water generator (120) is expressed by B = (y−x) A / z, and the load of the fresh water generator (120) is adjusted based on this formula to cool the engine (E). The amount of heat obtained by the cooling water can be appropriately distributed to the vaporizer (180) and the water generator (120).

  In the marine fuel gas supply system of the present embodiment, the heat source obtained while cooling water cools the engine (E) is preferentially used in the first heater (110), as in the first embodiment. The rest is used in the fresh water generator (120).

  The cooling water (L10 line) discharged from the engine (E) is branched into two flows as in the first embodiment, and one (L10 line) is sent to the first heater (110), and the other ( L12 line) bypasses the first heater (110). The cooling water (L12 line) bypassing the first heater (110) and the cooling water (L20 line) passing through the first heater (110) are merged to form a fresh water generator, as in the first embodiment. The point where the cooling water (L12 line) that is sent to (120) and bypasses the first heater (110) and the cooling water (L20 line) that passes through the first heater (110) merges is the first Similar to the embodiment, a first three-way valve (810) is installed. In the marine fuel gas supply system of the present embodiment, the amount of cooling water sent to the first heater (110) is adjusted by adjusting the opening of the first three-way valve (810) as in the first embodiment. Finally, the amount of heat transferred from the cooling water to the first heater (110) can be adjusted.

  Similar to the first embodiment, a temperature sensor (not shown) can be installed on the line (L4) through which the heat medium is sent from the first heater (110) to the vaporizer (180). The opening degree of the first three-way valve (810) is adjusted based on a temperature value sensed by a temperature sensor installed on the line.

  Moreover, the marine fuel gas supply system of this embodiment can also be operated so that the temperature of the heat medium flowing through the L4 line is maintained constant, as in the first embodiment.

  As in the first embodiment, the marine fuel gas supply system of the present embodiment sends the cooling water that has passed through the first heater (110) after being discharged from the engine (E) to the fresh water generator (120). And an air separator (330) installed on the line (L20). As in the first embodiment, the air separator (330) removes air contained in the cooling water supplied from the first heater (110) to the water generator (120), and the ship according to the present embodiment. This prevents failure of various devices provided in the fuel gas supply system for industrial use.

  On the other hand, the cooling water (L20 line) that has passed through the first heater (110) after being discharged from the engine (E) is branched into two flows as in the first embodiment, and one (L20 line). Is sent to the water maker (120), while the other (L22 line) bypasses the water maker (120). The cooling water (L22 line) bypassing the water maker (120) and the cooling water (L30 line) passing through the water maker (120) merge and re-engine (E) as in the first embodiment. In the same way as in the first embodiment, the cooling water (L22 line) that bypasses the water generator (120) and the cooling water (L30 line) that passes through the water generator (120) merge. A second three-way valve (820) is installed. In the marine fuel gas supply system of the present embodiment, the amount of cooling water sent to the water generator (120) is adjusted by adjusting the opening of the second three-way valve (820), as in the first embodiment. Finally, the amount of heat transferred from the cooling water to the fresh water generator (120) is adjusted.

  On the line (L30) through which the cooling water discharged from the water generator (120) is supplied to the engine (E), as in the first embodiment, a second temperature adjustment sensor (which adjusts the temperature of the cooling water) 220) is installed. The set value of the second temperature control sensor (220) decreases as the load on the engine (E) increases.

  As in the first embodiment, the marine fuel gas supply system of the present embodiment is the cooling water that has passed through the first heater (110) and the water generator (120) after being discharged from the engine (E). A cooler (130) for lowering the temperature is further provided. As in the first embodiment, the cooler (130) is a part of the amount of heat generated in the cooling water obtained by cooling the engine (E) to the first heater (110) and the water generator (120). If the temperature does not become sufficiently low even after supplying water, the temperature of the cooling water is lowered so that the cooling water is cooled to the temperature required for the engine (E).

  In the marine fuel gas supply system of the present embodiment, the cooling water (L30 line) discharged from the water generator (120) is branched into two flows as in the first embodiment, and one (L30 line). ) Is sent to the cooler (130), while the other (L32 line) bypasses the cooler (130). The cooling water (L32 line) bypassing the cooler (130) and the cooling water (L40 line) passing through the cooler (130) merge and are sent to the engine (E) as in the first embodiment. As in the first embodiment, a third three-way valve is provided at a point where the cooling water (L32 line) bypassing the cooler (130) and the cooling water (L40 line) passing through the cooler (130) merge. (830) is installed. In the marine fuel gas supply system of this embodiment, the amount of cooling water sent to the cooler (130) is adjusted by adjusting the opening of the third three-way valve (830), as in the first embodiment. Finally, the degree to which the cooling water is cooled by the cooler (130) is adjusted.

  In the marine fuel gas supply system of the present embodiment, the capacity of the cooler (130) is reduced as in the first embodiment, and the energy required for driving the cooler (130) can be reduced.

  In the marine fuel gas supply system of the present embodiment, as in the first embodiment, the heat source obtained while cooling water cools the engine (E) is preferentially used by the first heater (110), and the rest. Is used in the water generator (120), and the remaining heat source is cooled by the cooler (130) even if it is used in the water generator (120).

  Further, in the marine fuel gas supply system of the present embodiment, the cooling water discharged from the cooler (130) is cooled on the line (L40) supplied to the engine (E) as in the first embodiment. A third temperature adjustment sensor (230) for adjusting the temperature of the water is installed. The set value of the third temperature control sensor (230) becomes lower as the load of the engine (E) is higher, as in the first embodiment.

  Similar to the first embodiment, the marine fuel gas supply system of the present embodiment further includes at least one of a storage tank (160), an expansion tank (170), and an air discharge tank (140). Can do.

  Similar to the first embodiment, the storage tank (160) stores the remaining cooling water that has not been sent to the first heater (110) among the cooling water used for cooling the engine (E). A part of the cooling water stored in the storage tank (160) can be sent to the expansion tank (170) as in the first embodiment (L50 line). In the marine fuel gas supply system of this embodiment, as in the first embodiment, the consumption of cooling water that requires chemical treatment can be minimized.

  As in the first embodiment, the expansion tank (170) absorbs a volume change generated while the cooling water expands or contracts to improve the stability of the system, and plays a role of applying a pressure necessary for circulating the cooling water. To do. In the same manner as in the first embodiment, the expansion tank (170) is supplied with air discharged from the air discharge tank (140) in addition to the cooling water from the storage tank (160). When the pressure inside the expansion tank (170) is too high, the internal gas in the expansion tank (170) is discharged along the gas discharge line (L2) as in the first embodiment.

  Similar to the first embodiment, such an expansion tank (170) can be disposed approximately 20 m to 25 m above the engine room in which the engine (E) is disposed. The height of the expansion tank (170) varies depending on the cooling water temperature required by the engine (E).

  Unlike the first embodiment, the marine fuel gas supply system of the present embodiment is installed on a line (L10) through which cooling water discharged from the engine (E) is supplied to the first heater (110). Third pressurizing means (190) is further provided. The third pressurizing means (190) is installed when the first heater (110) is inevitably disposed at a high position and cooling water cannot be smoothly supplied to the first heater (110). Even when the second pressurizing means (420) is provided, it is installed when the pressure for supplying the cooling water to the first heater (110) is insufficient.

  As in the first embodiment, the air discharge tank (140) discharges air contained in the cooling water sent from the water generator (120) to the engine (E) to the expansion tank (170), and the temperature of the cooling water. It plays the role of mitigating the effects of changes in the volume of cooling water that changes suddenly in response to changes. The cooling water sent from the water generator (120) to the engine (E) is temporarily stored in the air discharge tank (140) and sent to the engine (E) as in the first embodiment.

  In addition, the marine fuel gas supply system of the present embodiment is provided on the line (L50) for supplying the cooling water discharged from the storage tank (160) to the expansion tank (170), as in the first embodiment. The first pressurizing means (410) may be further provided.

  As in the first embodiment, the first pressurizing means (410) includes a first water level adjusting device (310) for adjusting the water level of the storage tank (160) and a second water level for adjusting the water level of the expansion tank (170). It can operate in conjunction with the adjustment device (320). That is, in the first pressurizing means (410), as in the first embodiment, the water level of the storage tank (160) is equal to or higher than a predetermined height, or the water level of the expansion tank (170) is equal to or lower than a predetermined height. And the cooling water inside the storage tank (160) is sent to the expansion tank (170).

  Further, the marine fuel gas supply system of the present embodiment is similar to the first embodiment in that the second pressurizing means pressurizes the cooling water discharged from the water generator (120) and supplies it to the engine (E). (420) or one of the first valves (710) installed on the line (L10) through which cooling water is supplied from the engine (E) to the first heater (110) to prevent backflow of cooling water Or both can be further provided.

  As in the first embodiment, a plurality of second pressurizing means (420) may be connected in parallel. Similar to the first embodiment, the second pressurizing means (420) can pressurize the cooling water up to about 3 bar, and both the pressure for circulating the cooling water and the pressure required for the engine (E) are provided. Pressurize the cooling water to satisfy.

  When the second pressurizing means (420) is provided, similarly to the first embodiment, the cooling water is circulated only by the pressure of the second pressurizing means (420) without installing an additional pressurizing means. Thus, it is preferable to connect the apparatus installed on the circulation line in which the cooling water discharged from the engine (E) is supplied to the engine (E) again in series.

  The first valve (710) prevents the backflow of the cooling water supplied from the engine (E) to the first heater (110) when the second pressurizing means (420) is stopped. To do.

  Similarly to the first embodiment, the marine fuel gas supply system of the present embodiment is a second heater (150) that heats the cooling water discharged from the water generator (120) and supplied to the engine (E). Can further be provided. As in the first embodiment, the second heater (150) heats the cooling water by exchanging heat between the steam and the cooling water. Similar to the first embodiment, a third valve (730) can be installed on the steam supply line, and the amount of steam is adjusted by adjusting the opening of the third valve (730). Finally, the degree to which the cooling water is heated is adjusted.

  Similarly to the first embodiment, the second heater (150) is supplied with cooling water in order to prevent low temperature corrosion of the engine (E) when the ship is anchored and the engine (E) is not operated. It plays a role of heating to a temperature or higher and supplying it to the engine (E). When the second heater (150) is operated, the cooler (130) is generally not operated.

  When the marine fuel gas supply system of the present embodiment includes the second heater (150), as in the first embodiment, the load on the engine (E) is low and the cooling water heat source that can be used is small. The water generator (120) can be operated at 100%. In the marine fuel gas supply system of the present embodiment, even when the load on the engine (E) is low, the fresh water generator (120) is operated at 100%, and then the cooling water is supplied to the engine by the second heater (150). Since it is only necessary to heat to a predetermined temperature that can prevent low temperature corrosion in (E), the system can be operated more flexibly as in the first embodiment.

  Further, when the second heater (150) is provided, the cooling water discharged from the water generator (120) branches into two flows as in the first embodiment, and one (L60 line) is the first. 2 is sent to the heater (150) and the other (line L62) bypasses the second heater (150). The cooling water that bypasses the second heater (150) (L62 line) and the cooling water that passes through the second heater (150) (L60 line) merge to form an engine (E ) And the fourth valve (740) can be installed on the line (L62) through which the cooling water that bypasses the second heater (150) flows, as in the first embodiment. In the marine fuel gas supply system of the present embodiment, the amount of cooling water sent to the second heater (150) is adjusted by adjusting the opening of the fourth valve (740), as in the first embodiment. Finally, the degree to which the cooling water is heated by the second heater (150) can be adjusted.

  On the other hand, in the marine fuel gas supply system of the present embodiment, when the expansion tank (170) is provided, the first heater (110) is installed at a position higher than the expansion tank (170), unlike the first embodiment. Is done. In many cases, it is difficult to install the first heater (110) in the engine room. When the marine fuel gas supply system of the present embodiment is actually applied to a marine vessel, the first heater (110) is inevitably produced. Are often placed higher than the expansion tank (170).

  When both the expansion tank (170) and the first three-way valve (810) are provided, the first three-way valve (810) is preferably installed at a position lower than the expansion tank (170).

  In the marine fuel gas supply system of the present embodiment, when the second pressurizing means (420) is stopped, the first three-way valve (810) is a valve in the direction of the first heater (110) (upper side in FIG. 2). And the valves in the direction of L12 and the water generator (120) (the valves on the left side and the lower side in FIG. 2) remain open.

  Of the first three-way valve (810), when the valve in the direction of the first heater (110) (the upper valve in FIG. 2) is closed, the pressure of the second pressurizing means (420) is stopped and the cooling water is circulated. The loss of cooling water inside the pipe (L20 line) between the first three-way valve (810) and the first heater (110) installed at a position lower than the expansion tank (170) Pressure loss can be prevented.

  Also, if the L12 line and the valve in the direction of the water generator (120) (left and lower valves in FIG. 2) are kept open, the second pressurizing means (420) stops and the engine (E) Even if the cooling water supplied from the first heater (110) flows backward, the first valve (710) blocks the backward flow of the cooling water to the engine (E) and the third pressurizing means ( Backflow to 190) is also prevented. The cooling water flowing backward from the first heater (110) is sent to the water generator (120) via the L12 line and the first three-way valve (810).

  If the first three-way valve (810) is installed at a position higher than the expansion tank (170), when the second pressurizing means (420) fails, of the first three-way valve (810), Even if the valve (upper valve in FIG. 2) in the direction of the first heater (110) is closed, there is a risk that the pressure will drop to near the vapor pressure, a vacuum will be generated in the piping, and bubbles will be generated in the cooling water. Yes, it adversely affects the rigidity of the piping. In addition, there is a risk that the pressure and flow velocity of the cooling water will decrease rapidly, and water hammering (Water Hammering) may occur.

  Here, if it is possible to arrange the first heater (110) below the expansion tank (170), even if the second pressurizing means (420) fails, the first heater (110) There is no possibility that a vacuum will be generated in the pipe (L20 line) between the first three-way valve (810), but in a ship, the first heater (110) is necessarily installed above the expansion tank (170). Therefore, when the second pressurizing means (420) fails, a vacuum is not generated in the pipe (L20 line) between the first heater (110) and the first three-way valve (810). To do.

  Therefore, the marine fuel gas supply system of the present embodiment can prevent water hammering (Water Hammering), and can prevent a failure of the apparatus due to the backflow of cooling water.

  When the marine fuel gas supply system of the present embodiment includes all of the cooler (130), the air discharge tank (140), the second pressurizing means (420), and the second heater (150), Similarly to the embodiment, the cooler (130) is installed at the rear stage of the water generator (120), the air discharge tank (140) is installed at the rear stage of the cooler (130), and the rear stage of the air discharge tank (140). The second pressurizing means (420) is installed at the second stage, the second heater (150) is installed at the rear stage of the second pressurizing means (420), and the engine (E) is installed at the rear stage of the second heater (150). It is preferable to be installed.

  The marine fuel gas supply system of this embodiment includes a first three-way valve (810), a second three-way valve (820), a third three-way valve (830), a third valve (730), and a first temperature control sensor (210 ), The second temperature control sensor (220), or the third temperature control sensor (230), the first three-way valve (810), the second temperature control sensor (230) and the second temperature control sensor (230) are provided as in the first embodiment. The three-way valve (820), the third three-way valve (830), the third valve (730), the first temperature adjustment sensor (210), the second temperature adjustment sensor (220), and the third temperature adjustment sensor (230) are: The operation is controlled by the control panel (C).

  As in the first embodiment, the control panel (C) comprehensively analyzes the operation status of the system based on information collected by each connected device and the state of each device, and controls each device.

  In particular, in the marine fuel gas supply system of the present embodiment, when the second pressurizing means (420) is stopped, the first three-way valve (810) is a valve in the direction of the first heater (110) (FIG. 2). The algorithm can be configured to close the upper valve). The control panel (C) can automatically cope with a failure of the second pressurizing means (420).

  In the marine fuel gas supply system of the present embodiment as described above, in order to make maximum use of the heat source of the cooling water discharged from the engine (E) without losing the cooling water, as in the first embodiment, the cooling water The pipe (indicated by a double line in FIG. 2) through which the gas flows can be heat-insulated.

  The present invention is not limited to the above-described embodiments, and those having ordinary knowledge in the technical field to which the present invention belongs can be implemented by being modified or changed in various forms without departing from the technical spirit of the present invention. It is self explanatory.

Claims (31)

A vaporizer that vaporizes liquefied natural gas and supplies it to the engine;
A first heater that heats the fluid used as the heat medium in the vaporizer and heats the fluid used as the heat medium in the vaporizer after cooling the engine; and exhausted from the engine Using a part or all of the heat source of the cooling water that has passed through the first heater after being heated to obtain fresh water by heating seawater;
The marine fuel gas supply system, wherein the vaporizer vaporizes the liquefied natural gas by exchanging heat between the fluid heated by the first heater and the liquefied natural gas.   The marine fuel gas supply system according to claim 1, further comprising an expansion tank that absorbs a volume change generated while the cooling water expands or contracts. The engine is located in the engine compartment;
The marine fuel gas supply system according to claim 2, wherein the expansion tank is disposed 20 m to 25 m above the engine room.   The marine fuel gas supply system according to claim 2, wherein the first heater is disposed at a position higher than the expansion tank.   The marine fuel gas supply system according to claim 1, further comprising a second heater that heats the cooling water discharged from the water generator and supplied to the engine. The cooling water discharged from the engine branches into two flows, one is sent to the first heater, the other bypasses the first heater,
The marine vessel according to claim 2, further comprising a first three-way valve installed at a point where the cooling water that bypasses the first heater and the cooling water that has passed through the first heater merge. Fuel gas supply system.   The marine fuel gas supply system according to claim 6, wherein the first three-way valve is installed at a position lower than the expansion tank.   2. The marine fuel gas supply system according to claim 1, further comprising a cooler that lowers a temperature of the cooling water that has passed through the first heater and the fresh water generator after being discharged from the engine. A third temperature adjustment sensor installed on a line through which the cooling water discharged from the cooler is supplied to the engine to adjust the temperature of the cooling water;
9. The marine fuel gas supply system according to claim 8, wherein a set value of the third temperature control sensor decreases as the load of the engine increases. The heat source obtained while cooling water cools the engine is preferentially used in the first heater,
The rest is used in the water machine,
The marine fuel gas supply system according to claim 8, wherein the heat source remaining even after being used in the water generator is cooled by the cooler.   The marine vessel according to claim 2, further comprising a storage tank that stores the remaining cooling water that has not been sent to the first heater among the cooling water used to cool the engine. Fuel gas supply system. Further comprising a first pressurizing means installed on a line for supplying cooling water discharged from the storage tank to the expansion tank;
The marine fuel according to claim 11, wherein the first pressurizing unit operates when the water level of the storage tank is equal to or higher than a predetermined height, or the water level of the expansion tank is equal to or lower than a predetermined height. Gas supply system.   2. The marine fuel gas supply system according to claim 1, further comprising a second pressurizing unit that pressurizes cooling water discharged from the water generator and supplies the pressurized water to the engine.   The marine vessel according to claim 13, further comprising a first valve that prevents a reverse flow of cooling water supplied from the engine to the first heater when the second pressurizing unit is stopped. Fuel gas supply system.   The vaporizer, the first heater, the fresh water generator, and the second pressurizing unit are connected in series, and cooling water is circulated only by the second pressurizing unit. 14. The marine fuel gas supply system according to 13.   16. The apparatus according to claim 1, further comprising a third pressurizing unit installed on a line through which cooling water discharged from the engine is supplied to the first heater. Marine fuel gas supply system. The load of the water generator is
B = (y−x) A / z (the engine load is A, the maximum amount of heat transferred to the fluid used in the vaporizer is x, the water generator load is B, and the engine is cooled) The maximum amount of heat obtained by the cooling water is y, and the amount of heat required when the load of the fresh water generator is 100% is z)). The marine fuel gas supply system described in 1. A first temperature adjustment sensor installed on a line through which cooling water is supplied from the engine to the first heater to adjust the temperature of the cooling water to a constant; or cooling water discharged from the water generator is the engine One or both of a second temperature control sensor installed on the line supplied to the head and for adjusting the temperature of the cooling water;
The marine fuel gas supply system according to any one of claims 1 to 15, wherein a set value of the second temperature control sensor decreases as the load of the engine increases.   The cooling water that has passed through the first heater after being discharged from the engine is installed on a line that is sent to the water generator, and further includes an air separator that removes air contained in the cooling water. The marine fuel gas supply system according to any one of claims 1 to 15.   The marine fuel gas supply system according to any one of claims 1 to 15, further comprising an air discharge tank that discharges air contained in cooling water sent from the water generator to the engine. .   The marine fuel gas supply system according to any one of claims 1 to 15, wherein a part or all of the piping through which the cooling water flows is subjected to heat insulation. 1) a step of heat-exchanging the cooling water discharged after cooling the engine and a fluid used as a heat medium and heating the fluid with a first heater;
2) a step of evaporating the liquefied natural gas by exchanging heat between the fluid heated by the heat exchange in the step of 1) and the liquefied natural gas;
3) supplying the engine with the natural gas vaporized in the step 2); and 4) part or all of the heat source of the cooling water used for heat exchange of the fluid in the step 1). A step of heating seawater with a water generator to obtain fresh water;
A marine fuel gas supply method comprising:   5) The marine fuel gas supply method according to claim 22, further comprising a step of heating the cooling water used in the fresh water generator in the step of 4). The step 5)
The marine fuel gas supply method according to claim 23, wherein when the engine is not operated, the cooling water is heated to a predetermined temperature or higher that prevents low temperature corrosion of the engine. The step 5)
In the step 4), if the temperature of the cooling water is lower than the temperature at which low temperature corrosion of the engine is prevented when the water generator is operated 100%, the temperature of the engine is reduced after the water generator is operated 100%. The marine fuel gas supply method according to claim 23, wherein the cooling water is heated to a predetermined temperature or higher for preventing corrosion.   5) The marine fuel gas supply method according to claim 22, further comprising a step of pressurizing the cooling water discharged from the fresh water generator by a second pressurizing means and supplying the pressurized water to the engine. The cooling water discharged from the engine branches into two flows, one is sent to the first heater, the other bypasses the first heater,
27. The marine fuel gas according to claim 26, wherein a first three-way valve is installed at a point where the cooling water bypassing the first heater and the cooling water passing through the first heater merge. Supply method.   28. The valve according to claim 27, wherein when the second pressurizing means is stopped, in the first three-way valve, the valve in the first heater direction is closed and the other valves are kept open. Ship fuel gas supply method.   29. The algorithm according to claim 28, wherein an algorithm is configured to automatically close the valve in the first heater direction by the control panel in the first three-way valve when the second pressurizing means stops. The marine fuel gas supply method as described. Place the engine in the engine room,
An expansion tank that absorbs the volume change generated while the cooling water expands or contracts is disposed 20 m to 25 m above the engine room,
A first heater for heating a fluid used as a heat medium for vaporizing liquefied natural gas is disposed at a position higher than the expansion tank;
The first three-way valve installed at a point where the cooling water bypassing the first heater and the cooling water passing through the first heater merge is installed at a position lower than the expansion tank, Marine fuel gas system. The engine load is A, the maximum amount of heat transferred to the fluid used as a heat medium in the vaporizer is x, the load of the fresh water generator is B, the maximum amount of heat that cooling water obtains while cooling the engine is y, When the amount of heat required when the load of the water machine is 100% is z,
A marine fuel gas supply method that distributes the amount of heat obtained by the cooling water to the vaporizer and the water generator while cooling the engine according to an equation of Ax + Bz = Ay.

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