KR20220103249A - Apparatus for controlling pressure of LPG Fuel Tank - Google Patents

Abstract

A pressure control device for a ship fuel storage tank is disclosed. The pressure control device of a fuel storage tank according to an embodiment of the present invention is the pressure control device for a ship fuel storage tank, comprising: a first storage tank for storing crude oil, a second storage tank for liquefying and storing volatile organic compounds generated in crude oil in a re-liquefaction part, and a fuel storage tank for storing fuel for propulsion of a ship. The re-liquefaction part includes: a pre-processing part that performs compression, cooling, gas-liquid separation, and moisture removal of volatile organic compounds; a pre-cooling part that performs pre-cooling by heat-exchanging the volatile organic compound that has passed through the pre-processing part with a heat exchange medium; and a cooling part for cooling the pre-cooled volatile organic compound by exchanging heat with a refrigerant, wherein the fuel storage tank is provided to exchange heat with the cooling part when an internal pressure increases. The pressure control device for a ship fuel storage tank according to an embodiment of the present invention is intended to efficiently suppress an increase in pressure in a fuel tank.

Description

Apparatus for controlling pressure of LPG Fuel Tank

The present invention relates to a pressure regulating device for a fuel storage tank, and more particularly, to a pressure regulating device for a marine fuel storage tank capable of regulating an increased pressure inside the fuel storage tank.

After crude oil is stored in the offshore production facility, it is supplied to the storage tank of the crude oil carrier, and the shuttle tanker transports the crude oil to the onshore refining facility.

During the loading of crude oil, a significant amount of volatile organic compounds (VOC) is generated from the loaded crude oil in the storage tank of the carrier. Since volatile organic compounds can cause air pollution when discharged to the outside, they are discharged by burning or recovered through a predetermined process. In some countries, where environmental regulations have been strengthened, the emission of these volatile organic compounds is strongly restricted.

As an example, in Korea Patent Registration No. 10-1271761 (registered on May 30, 2013), a carrier is provided with a system for liquefying volatile organic compounds generated in the storage tank of the carrier by exchanging heat with fuel LNG, and then recovering it back to the storage tank of the carrier. are doing Such a system is not only expensive, but also takes up a lot of space on the carrier.

On the other hand, some carriers use LPG as fuel, which has a similar composition to volatile organic compounds generated in oil storage tanks. LPG is stored under high pressure and room temperature conditions and is used as fuel by mixing with volatile organic compounds. However, when the internal pressure of the LPG fuel tank rises due to external conditions, etc., conventionally, the gas in the LPG tank is vented to lower the pressure, but the discharged gas is recently subject to strong environmental regulations due to concerns about air pollution as described above. It is currently being limited.

Korean Patent Registration No. 10-1271761 (Registered on May 30, 2013)

The apparatus for regulating the pressure of a ship fuel storage tank according to an embodiment of the present invention is intended to effectively suppress an increase in pressure in the fuel tank.

According to one aspect of the present invention, a first storage tank for storing crude oil, a second storage tank for liquefying and storing volatile organic compounds generated from crude oil in a re-liquefaction unit, and a fuel storage tank for storing fuel for propelling a ship In the pressure control device of a marine fuel storage tank comprising A pre-cooling unit for performing pre-cooling and a cooling unit for cooling by heat-exchanging the pre-cooled volatile organic compound with a refrigerant, wherein the fuel storage tank has a pressure regulating device for a ship fuel storage tank that is provided to exchange heat with the cooling unit when the internal pressure increases can be provided.

In addition, the pre-cooling unit and the cooling unit are connected by a main line, a first valve is provided in the main line, the fuel storage tank and the cooling unit are connected by a fuel line, and a second valve is provided in the fuel line, , The first valve and the second valve may be selectively opened and closed by the control unit.

In addition, the cooling unit may exchange heat with the precooling unit to re-liquefy the volatile organic compound when crude oil is loaded, and may exchange heat with the fuel storage tank to reduce the pressure of the fuel storage tank during operation.

In addition, the cooling unit may further include a refrigerant storage tank for storing the refrigerant, a compressor, and a refrigerant storage unit including a cooler.

In addition, the fuel storage tank further includes a sub-cooling unit for lowering the fuel temperature, and the refrigerant storage unit is selectively connected to any one of a first line connected to the cooling unit and a second line connected to the sub-cooling unit. It may be connected to provide heat exchange with the fuel storage tank.

In addition, further comprising a fuel supply unit for supplying fuel gas from the fuel storage tank to the engine of the carrier, the fuel supply unit is connected to the fuel storage tank to pressurize the liquefied fuel, the pump is connected to the pressurized liquefied fuel A carburetor supplying the engine by vaporizing, a first fuel pipe connecting the pump and the carburetor, a second fuel pipe connecting between the carburetor and the engine, and recovering unburned fuel gas from the engine for reuse. It may include a third fuel pipe connected to the secondary fuel pipe.

In addition, the fuel storage tank further includes a sub-cooling unit for lowering the fuel temperature, and the refrigerant storage unit is selectively connected to any one of a first line connected to the cooling unit and a second line connected to the sub-cooling unit. and the third fuel pipe may be selectively connected to the sub-cooling unit to exchange heat with unburned fuel gas.

When the pressure inside the fuel tank increases, the pressure regulating device of the ship fuel storage tank according to an embodiment of the present invention controls the temperature and pressure of the fuel through heat exchange with the cooling system in the ship, for example, the cooling unit or the sub-cooling unit of the re-liquefaction unit. Since it can reduce the emission gas, it is not only unnecessary to have facilities related to exhaust gas, but also air pollution can be effectively prevented.

The effects of the present invention are not limited to the above-mentioned effects, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

1 is a diagram schematically illustrating a pressure control device for a ship fuel storage tank and a reliquefaction unit used therein according to an embodiment of the present invention.
Figure 2 is an enlarged view of the cooling unit of the re-liquefaction unit used in the pressure control device of the fuel storage tank of the ship according to an embodiment of the present invention.
3 is a diagram schematically illustrating a cooling unit of a re-liquefaction unit used in a pressure control device of a ship fuel storage tank according to another embodiment of the present invention.
4 is a diagram schematically illustrating a sub-cooling unit used in a pressure control device of a ship fuel storage tank according to another embodiment of the present invention.
5 is a view showing an example of the sub-cooling unit and the fuel supply unit used in the pressure control device of the fuel storage tank of the ship according to an embodiment of the present invention.
6 is a view showing another example of the sub-cooling unit and the fuel supply unit used in the pressure control device of the fuel storage tank of the ship according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments introduced below are provided as examples so that the spirit of the present invention can be sufficiently conveyed to those of ordinary skill in the art to which the present invention pertains. The present invention is not limited to the embodiments described below and may be embodied in other forms. In order to clearly explain the present invention, parts irrelevant to the description are omitted from the drawings, and in the drawings, the width, length, thickness, etc. of components may be exaggerated for convenience. Like reference numerals refer to like elements throughout.

1 is a view schematically showing a pressure regulating device of a ship fuel storage tank according to an embodiment of the present invention.

Prior to the description, the pressure control device of the fuel storage tank according to this embodiment is a first storage tank T1 (hereinafter also referred to as an oil storage tank) for storing crude oil and a reliquefaction unit for volatile organic compounds generated from crude oil. A second storage tank T2 (hereinafter, also referred to as an oil vapor storage tank) for liquefying and storing, and a fuel storage tank T3 for storing fuel for propelling the oil carrier may be provided in the carrier. In addition, although this embodiment exemplifies an LPG fuel vessel that can be used as a fuel by mixing with a volatile organic compound (or oil vapor), it may also be applied to a vessel using LNG as a fuel through appropriate modifications and variations.

In addition, the reliquefaction unit for performing liquefaction of volatile organic compounds is generally referred to as a volatile organic compound liquefaction system. let it be

To this end, the reliquefaction unit includes a pre-processing unit 110 for performing compression, cooling, gas-liquid separation and moisture removal of the fluid (volatile organic compound or oil vapor), and pre-cooling the fluid passing through the pre-processing unit 110 with a heat exchange medium. The pre-cooling unit 120 performing ), a main supply line (L1) connecting the pre-processing unit 110, the pre-cooling unit 120, and the cooling unit 130, and a pre-cooling unit ( 120) may include a main return line (L2) for supplying the heat exchange medium. The main supply line L1 and the main return line L2 may be collectively referred to as a main line hereinafter.

According to this embodiment, the fuel storage tank T3 lowers the internal pressure by exchanging heat with the cooling unit 130 of the reliquefaction unit when the internal pressure exceeds a predetermined set value. To this end, the fuel storage tank T3 may include a fuel supply line L4 and a fuel return line L5 connected to the cooling unit 130 . The fuel supply line L4 and the fuel return line L5 may be collectively referred to as a fuel line hereinafter.

In addition, according to the present embodiment, the vessel may be provided with a control unit 140 for controlling the operation of the reliquefaction unit and the pressure of the fuel storage tank. This control unit 140 will be described later.

Looking at the reliquefaction unit in more detail, the pre-processing unit 110 includes an impurity remover 111 for removing impurities from the fluid transferred from the oil storage tank T1, a compressor 112 for compressing the fluid, and the compressed The oil separator 113 for separating oil from the fluid, the cooler 114 for cooling the fluid separated by the oil separator 113, and the gas-liquid separator 115 for gas-liquid separation of the fluid cooled by the cooler 114 ) and may include a moisture remover 116 for removing moisture from the gas-phase fluid among the gas-liquid separated fluid by the gas-liquid separator 115 .

The precooling unit 120 may include a first precooling unit 120a and a second precooling unit 120b connected in parallel, the first precooling unit 120a and the second precooling unit 120b, and a cooling unit ( A first valve V1 may be provided in the pipeline between 130 .

In addition, the main return line (L2) of the main line includes a first return line (L2-1) that supplies a gaseous component of the fluid cooled by the cooling unit 130 to the heat exchange medium of the first precooling unit 120a and , a second return line L2-2 for supplying a liquid component of the fluid cooled by the cooling unit 130 to the heat exchange medium of the second pre-cooling unit 120b.

On the other hand, when the reliquefaction unit liquefies the fluid generated in the process of loading crude oil into the storage tank of the crude oil carrier, the liquid component of the fluid generated by the cooling unit 130 passes through the second return line (L2-2). After being heated by passing through the second pre-cooling unit 120b through the gas-liquid separator 115, the gas-liquid separator 115 and the cooling unit 130 are separated to be stored in the fluid storage tank T2 together with the liquid components separated by the gas-liquid separator 115. A storage line (L3) for connecting may be further provided.

In addition, the gaseous component of the fluid generated by the cooling unit 130 passes through the first pre-cooling unit 120a through the first return line L2-1 and is heated, and then supplied as fuel to the consumer 200 . do. Here, the demand 200 may be an engine or a generator of a ship.

Hereinafter, a process of liquefying the volatile organic material in the oil storage tank T1 using the re-liquefaction unit will be described in more detail.

First, when liquefying a volatile organic compound generated in the oil storage tank T1 of a crude oil carrier, for example, a volatile organic compound generated in the process of loading crude oil, the impurity remover 111 injects water to the volatile organic compound Removes impurities such as droplets and dust from In this way, it is possible to prevent problems such as corrosion of the compressor 112 due to the introduction of impurities into the compressor 112, which will be described later. When impurities are previously removed before being transferred to the reliquefaction unit, the impurity remover 111 may be omitted.

Then, the compressor 112 compresses the volatile organic compound according to the set value. For example, the compressor 112 may compress the volatile organic compound to 12 barg. Two or more compressors 112 may be connected in parallel as shown.

Then, the oil separator 113 separates the oil from the volatile organic compound compressed by the compressor 112 . The oil is injected into the compressor 112 for lubrication and sealing work, and may be separated from the volatile organic compound by the oil separator 113 . When the means for separating oil after the compression process by the compressor 112 is provided in the compressor together, the oil separator 113 may be omitted.

Then, the cooler 114 cools the volatile organic compound according to the set value. The volatile organic compound is in a state in which the temperature is increased to about 120° C. while passing through the compressor 112 described above. These volatile organic compounds may be cooled by water or glycol while passing through the cooler 114 .

Then, the gas-liquid separator 115 separates the volatile organic compound cooled by the cooler 114 into gas-liquid. The liquid component (indicated by the solid line in FIG. 1) separated by the gas-liquid separator 115 is stored in the fluid storage tank T2 through the storage line L3, and the component in the gas phase (indicated by the dotted line in FIG. 1) is a water remover (116) flows.

The moisture remover 116 removes moisture from the volatile organic compound in the gas phase separated by the gas-liquid separator 115 including the adsorbent, for example, when cooled by the cooling unit 130 to be described later. Icing can prevent the occurrence of

Next, the precooling unit 120 heats the volatile organic compound from which moisture has been removed by the water remover 116 with the heat exchange medium supplied from the cooling unit 130 to perform precooling. The pre-cooling unit 120 may include a first pre-cooling unit 120a and a second pre-cooling unit 120b connected in parallel.

The cooling unit 130 heats the volatile organic compound pre-cooled through the pre-cooling unit 120 with the refrigerant to cool it. Here, propylene may be used as the refrigerant. When the volatile organic compound is cooled by the cooling unit 130 , it may be separated into a heat exchange medium of a gaseous component and a liquid component, respectively.

That is, the gaseous component is supplied to the heat exchange medium of the first precooling unit 120a through the first return line L2-1, and the liquid component is supplied to the second precooling unit 120b through the second return line L2-2. ) is supplied as a heat exchange medium and heated.

The gaseous component (volatile organic compound in a gaseous state) may be used as a fuel for the consumer 200 such as an engine, a boiler, etc. as the temperature rises through the first pre-cooling unit 120a. In addition, the liquid component (volatile organic compound in liquid state) is heated to room temperature through the second pre-cooling unit 120b, and is cooled together with the liquid component separated by the above-described gas-liquid separator 115 with the gas-liquid separator 115. It may be stored in the fluid storage tank T2 through the storage line L3 connecting the unit 130 . The liquid volatile organic compound stored in the fluid storage tank T2 may be used as a fuel for a ship or mixed with oil during the process of loading and unloading oil.

2 and 3 illustrate in more detail the cooling unit 130 of the re-liquefaction unit used in the pressure control device of the ship fuel storage tank according to the present embodiment. The refrigerant of the cooling unit 130, for example, propylene is vaporized by obtaining heat of evaporation while exchanging heat with the volatile organic compound as described above.

The cooling unit 130 includes a refrigerant storage tank 152 for storing the refrigerant, a compressor 154 such as a compressor, a condenser (not shown), and a refrigerant storage unit 150 including a cooling means 156 such as a cooler. ) may be further included. The refrigerant storage tank 152 stores the refrigerant in a low-temperature and low-pressure state, and when the temperature rises, the refrigerant cycle is circulated to lower the temperature of the refrigerant. Through this, the temperature of the refrigerant can be lowered to about -47.4°C, so that the refrigerant vaporized through heat exchange can be liquefied and used continuously.

FIG. 2 shows that the pre-cooling unit 120 exchanging heat with the cooling unit 130 and the fuel storage tank T3 are connected in a multi-stream heat exchange method, and FIG. 3 is an optional view by installing a plurality of valves in the pipeline. so that it can be opened and closed.

The first valve V1 is a valve installed on the line between the first and second pre-cooling units 120a and 120b and the cooling unit 130 , and the second valve V2 is the fuel storage tank T3 and the cooling unit 130 . ) is a valve installed on the line between The 1-1 valve V1-1 is a valve that is selectively opened and closed with the first valve V1, and the 2-1 valve V2-1 is a valve that is selectively opened and closed with the second valve V2.

According to the present embodiment, the controller 140 may selectively control the opening and closing of the valves V1, V1-1, V2, and V2-1. For example, the control unit 140 opens the first valve V1 and closes the second valve V2 when crude oil is loaded to re-liquefy the volatile organic compound using the cooling unit 130, and the operation of the vessel During the operation, the first valve V1 is closed and the second valve V2 is opened to reduce the internal pressure of the fuel storage tank T3 using the cooling unit 130 .

4 is a view showing a pressure regulating device of a ship fuel storage tank according to another embodiment of the present invention.

Referring to the drawings, the vessel having the apparatus for regulating the pressure of the fuel storage tank according to the present embodiment may further include a subcooling unit 160 .

The sub-cooling unit 160 is a device for coolly cooling gaseous fuel (LPG) using the refrigerant of the refrigerant storage unit 150, from the fuel storage tank T3 to the sub-cooling unit 160 using a pump. When the fuel is transferred, the sub-cooler further lowers the temperature of the LPG to cool it, and then returns the cooled LPG to the fuel storage tank (T3) to spray it in the tank. First, by spraying the cooled LPG, the gas temperature in the fuel storage tank is lowered to lower the pressure in the tank due to the effect of gas shrinkage, and secondly, the atomized LPG lowers the LPG temperature in the tank to generate BOG. By reducing the pressure, the internal pressure of the tank does not rise.

As shown in FIG. 4 , the sub-cooling unit 160 is a second pipeline that is separate from the first line connecting the cooling unit 130 and the refrigerant storage unit 150 between the refrigerant storage unit 150 and the refrigerant storage unit 150 . It can be connected separately through 2 lines. In addition, a third valve V3 is installed between the refrigerant storage unit 150 and the sub-cooling unit 160 , and a flow meter 162 and a thermometer 164 between the fuel storage tank T3 and the sub-cooling unit 160 . ) can be installed in the fuel supply and discharge lines respectively. Through this, the control unit 140 effectively controls the amount of refrigerant injected into the sub-cooling unit 160 based on the flow rate of fuel entering from the fuel storage tank T3 and the temperature of the fuel exiting through the sub-cooling unit 160 . can do.

5 is a view showing an example of a fuel supply unit of a ship used in the pressure control device of the fuel storage tank according to an embodiment of the present invention. 5 exemplifies a system in which the fuel supply unit 170 is connected to the subcooling unit 160 of the reliquefaction unit shown in FIG. 4, but is not limited thereto. Of course, it can be connected.

As shown in FIG. 5 , the fuel supply unit 170 is a system for supplying LPG fuel gas to the propulsion engine of a ship, and is connected to a storage tank T3 in which LPG fuel is stored, and the storage tank to pressurize the liquefied fuel. A pump 172, a vaporizer 174 connected to the pump 172 to vaporize the pressurized liquefied fuel and supplying it to the engine 176, and a cooler for recovering and re-supplying unburned fuel from the engine 176 ( 178) may be included. The pump 172 and the carburetor 174 are connected to the first fuel pipe, the carburetor 174 and the engine 176 are connected to the second fuel pipe, and the third fuel pipe in which the cooler 178 is installed is the carburetor 174 ) can be connected to the second fuel pipe at the rear end. Here, the pump 172 may be provided separately as a low-pressure pump and a high-pressure pump, wherein the low-pressure pump is provided in the fuel storage tank T3 and the high-pressure pump is provided between the carburetor 174 and the engine 176. have.

6 is a view showing another example of the fuel supply unit used in the pressure control device of the fuel storage tank of the ship according to an embodiment of the present invention. In this embodiment, different points from the embodiment of FIG. 5 will be mainly described, and since the same reference numerals perform the same functions, a detailed description thereof will be omitted.

The fuel supply unit 170 according to this embodiment omits the fuel return pipe of FIG. 5 , that is, the cooler 178 provided in the third fuel pipe, and instead heats the third fuel pipe with the subcooling unit 160 . It is connected using the input/exit piping of the fuel storage tank (T3) and a plurality of fourth valves (V4). As the controller 140 selectively opens and closes the plurality of fourth valves V4, the pressure (temperature) of the fuel storage tank T using one cooling unit 160 as well as the pressure (temperature) of the LPG fuel recovered from the engine It can also effectively lower the temperature.

In the above, specific embodiments have been shown and described. However, the present invention is not limited to the above-described embodiments, and those of ordinary skill in the art to which the invention pertains may make various changes without departing from the spirit of the invention as set forth in the claims below. will be able

110..Pre-processing section 111..Impurity remover
112..Compressor 113..Oil Separator
114..cooler 115..gas-liquid separator
116..moisture eliminator 120..precooling part
130..Cooling unit 140..Control unit
150..Refrigerant storage unit 160..Subcooling unit
170..Fuel supply
T1.. 1st storage tank
T2..Second storage tank
T3..Fuel storage tank

Claims (7)

A ship fuel storage tank comprising a first storage tank for storing crude oil, a second storage tank for liquefying and storing the volatile organic compound generated from the crude oil in a re-liquefaction unit, and a fuel storage tank for storing fuel for propelling the ship In the pressure control device of
The reliquefaction unit includes a pre-processing unit for performing compression, cooling, gas-liquid separation and water removal of the volatile organic compound, a pre-cooling unit for performing pre-cooling by exchanging the volatile organic compound passing through the pre-processing unit with a heat exchange medium, and the pre-cooled volatile organic compound. It includes a cooling unit for cooling the organic compound by heat exchange with the refrigerant,
The fuel storage tank is a pressure regulating device for a marine fuel storage tank that is provided to exchange heat with the cooling unit when the internal pressure increases. The method of claim 1,
The pre-cooling unit and the cooling unit are connected to a main line, and a first valve is provided in the main line,
The fuel storage tank and the cooling unit are connected by a fuel line, and a second valve is provided in the fuel line,
The first valve and the second valve are selectively opened and closed by the control unit pressure control device of the fuel storage tank of the ship. 3. The method of claim 1 or 2,
The cooling unit heat-exchanges with the pre-cooling unit to re-liquefy the volatile organic compound when crude oil is loaded, and a pressure control device for a ship fuel storage tank for heat exchange with the fuel storage tank to reduce the pressure of the fuel storage tank during operation. The method of claim 1,
The cooling unit is a refrigerant storage tank for storing the refrigerant, and a compressor, and a pressure control device for a marine fuel storage tank further comprising a refrigerant storage unit comprising a cooler. 5. The method of claim 4,
Further comprising a sub-cooling unit for lowering the fuel temperature of the fuel storage tank,
The refrigerant storage unit is selectively connected to any one of a first line connected to the cooling unit and a second line connected to the sub-cooling unit, and a pressure control device for a marine fuel storage tank provided to exchange heat with the fuel storage tank. . 5. The method of claim 4,
Further comprising a fuel supply unit for supplying fuel gas from the fuel storage tank to the engine of the carrier,
The fuel supply unit includes a pump connected to the fuel storage tank to pressurize the liquefied fuel, a carburetor connected to the pump to vaporize the pressurized liquefied fuel and supply it to the engine, a first fuel pipe connecting the pump and the carburetor, and a carburetor and a second fuel pipe connecting between the and the engine, and a third fuel pipe connected to the second fuel pipe to recover and reuse unburned fuel gas in the engine. 7. The method of claim 6,
Further comprising a sub-cooling unit for lowering the fuel temperature of the fuel storage tank,
The refrigerant storage unit is selectively connected to any one of a first line connected to the cooling unit and a second line connected to the sub cooling unit,
The third fuel pipe is selectively connected to the sub-cooling unit to heat-exchange unburned fuel gas.

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