KR101516913B1 - Liquefied natural gas vaporizer - Google Patents

Abstract

A liquefied natural gas vaporizer is disclosed. According to one embodiment, a liquefied natural gas (LPG) vaporizer includes: a heating medium storage portion in which a first heat transfer medium is stored; A water tank temperature sensor for measuring a temperature of the first heat transfer medium stored in the heat medium storage unit; A modular heat pump having one side receiving heat from seawater and the other side transmitting heat to the first heat transfer medium and having a plurality of heat pumps; A seawater temperature difference sensor for measuring a temperature difference between seawater introduced into the modular heat pump and seawater discharged through the modular heat pump; A seawater circulation pump for introducing seawater into the modular heat pump and controlling the amount of seawater flowing into the modular heat pump according to a temperature difference measured by the seawater temperature difference sensor; A heat medium temperature difference sensor for measuring a temperature difference between a first heat transfer medium discharged from the heat medium storage unit and flowing into the modular heat pump and a first heat transfer medium discharged from the modular heat pump and then introduced into the heat medium storage unit, ; The first heat transfer medium discharged from the heat medium storage unit and having passed through the modular heat pump is introduced into the heat medium storage unit again and the first heat transfer member is introduced into the heat medium storage unit by the temperature difference measured by the heat medium temperature difference detection sensor, A heating medium circulation pump for controlling the amount of the medium; And an LNG flow tube in which at least a part of the LNG flow tube is accommodated in the heat medium storage part, exchanges heat with the first heat transfer medium, and the liquid natural gas flows.

Description

[0001] LIQUEFIED NATURAL GAS VAPORIZER [0002]

The present invention relates to a liquefied natural gas vaporizer, and more particularly, to a liquefied natural gas vaporizer for vaporizing a liquefied natural gas by using a heat pump having seawater as a heat source.

Conventional liquefied natural gas vaporizers mainly include a method in which a heat exchanger is submerged in a water tank and a water in a water tank is heated using a high temperature combustion gas generated by burning fuel gas and air in a burner installed in the water tank Liquefied natural gas was vaporized. The liquefied natural gas (LNG) is introduced into the lower portion of the heat exchanger, and is transferred to the upper side of the heat exchanger.

In this process, since a large amount of fuel gas is used to heat the water in the water tank, there is an uneconomical problem that the fuel cost is increased, and there is a problem that the environmental pollution due to the combustion exhaust gas resulting from the combustion of the fuel gas may occur there was.

The present invention provides a vaporization apparatus and a vaporization method for vaporizing liquefied natural gas in an environmentally friendly manner using seawater as a heat source.

According to an embodiment, a liquefied natural gas (LNG) vaporization apparatus includes: a heating medium storage portion in which a first heat transfer medium is stored; A water tank temperature sensor for measuring a temperature of the first heat transfer medium stored in the heat medium storage unit; A modular heat pump having one side receiving heat from seawater and the other side transmitting heat to the first heat transfer medium and having a plurality of heat pumps; A seawater temperature difference sensor for measuring a temperature difference between seawater introduced into the modular heat pump and seawater discharged through the modular heat pump; A seawater circulation pump for introducing seawater into the modular heat pump and controlling the amount of seawater flowing into the modular heat pump according to a temperature difference measured by the seawater temperature difference sensor; A heat medium temperature difference sensor for measuring a temperature difference between a first heat transfer medium discharged from the heat medium storage unit and flowing into the modular heat pump and a first heat transfer medium discharged from the modular heat pump and then introduced into the heat medium storage unit, ; The first heat transfer medium discharged from the heat medium storage unit and having passed through the modular heat pump is introduced into the heat medium storage unit again and the first heat transfer member is introduced into the heat medium storage unit by the temperature difference measured by the heat medium temperature difference detection sensor, A heating medium circulation pump for controlling the amount of the medium; And an LNG flow tube in which at least a part of the LNG flow tube is accommodated in the heat medium storage part, exchanges heat with the first heat transfer medium, and in which liquid natural gas flows.

According to the present invention, since it is not necessary to use a large amount of fossil fuel to vaporize liquefied natural gas, energy can be saved and economic loss due to fuel cost can be reduced.

In addition, the thermal energy obtained from seawater is natural energy, and there is little change in temperature depending on the season, so that it can be used stably as a low-temperature heat source of the heat pump.

Also, it is possible to use the hot water discharged from the power plant as a heat source of the heat pump or to preheat the seawater as a heat source. Accordingly, it is possible to solve the disposal problem of the hot water discharged from the power plant, and the efficiency of the heat pump using seawater as a heat source can be improved.

Further, according to the fluctuation of the vaporized amount of the liquefied natural gas, unnecessary operation of the heat pump can be reduced, energy and the cost can be saved, and the performance of the heat pump can be maintained optimally.

Further, in a situation where the liquefied natural gas is sufficiently liquefied, the unnecessary number of rotations of the heat medium circulation pump 70 and the seawater circulation pump 60 is reduced, thereby minimizing power consumption.

1 is a schematic view showing a conventional liquefied natural gas vaporizer.
2 is a schematic diagram of an improved liquefied natural gas vaporization apparatus according to one embodiment.
3 is an enlarged schematic view of the heat pump of FIG.
4 is a flowchart of a liquefied natural gas vaporization method according to an embodiment.
5 is a view showing a liquefied natural gas vaporizing apparatus according to another embodiment.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings. It should be understood, however, that the spirit of the present invention is not limited to such embodiments, and that the spirit of the present invention may be suggested by adding, changing, or deleting constituent elements of the embodiments, .

1 is a schematic view showing a conventional liquefied natural gas vaporizer.

Referring to FIG. 1, a conventional liquefied natural gas vaporizer 1 includes a water tank 2, a burner 3, and an LNG flow pipe 4.

The water tank 2 may be formed in a rectangular parallelepiped shape having an open top. An empty space is formed in the water tank 2, and the space inside the water tank 2 can be filled with water.

The burner (3) and the LNG flow pipe (4) may be provided in the water tank (2). The water tank 2 may be formed to have a size sufficient to accommodate the burner 3 and the LNG flow pipe 4 together.

In addition, an exhaust gas outlet 5 through which the combustion exhaust gas generated by the burner 3 can escape may be provided on the water tank 2.

The burner (3) may be provided inside the water tub (2). The burner 3 can generate a high-temperature combustion heat by burning a fuel gas such as natural gas (NG). The burner 3 can heat the water in the water tank 2 by using a fuel gas flowing into the burner 3 and a high temperature combustion gas generated by burning the air. In the process of burning the fuel gas by the burner 3, combustion gas as well as various other combustion products can be produced. Such combustion products may include carbon monoxide, carbon dioxide gas, nitrogen oxides, etc., which are generally contained in the combustion gas, though they vary depending on the type of the fuel gas. Thus, the combustion products causing air pollution are discharged to the atmosphere through the exhaust gas outlet 5, which may cause environmental pollution and the like.

The LNG flow pipe 4 can be received in the water tank 2, and most of the water is immersed in the water in the water tank 2.

The LNG flow pipe 4 absorbs heat from the burner 3 and receives heat from the water inside the heated water tank 2 to receive the liquid natural gas flowing in the LNG flow pipe 4 LNG) can be vaporized. The liquefied natural gas (LNG) can receive the heat of the heated water while moving from the lower side to the upper side of the LNG flow pipe 4, and can vaporize from the liquid state to the gaseous state. At this time, the LNG flow pipe 4 may be formed of copper or stainless steel having a high thermal conductivity so that heat exchange can be performed well.

In the conventional liquefied natural gas vaporizing apparatus 1, a large amount of fuel gas is required in order to obtain high-temperature combustion heat, which is a cause of increase in fuel cost, which is uneconomical. Further, the combustion exhaust gas generated by the combustion is discharged to the atmosphere through the exhaust gas outlet 5, thereby causing environmental pollution.

Therefore, in order to solve the above problem, a heat pump 30, which uses seawater s as a heat source, is used as a method for heating the water in the water tank 2 instead of the burner 3 generating combustion heat. The problem of the conventional liquefied natural gas vaporizer 1 can be solved.

FIG. 2 is a schematic view showing an improved liquefied natural gas vaporizing apparatus according to an embodiment, and FIG. 3 is an enlarged schematic view of the heat pump of FIG. 2. FIG.

2 and 3, a liquefied natural gas vaporizer 10 according to an embodiment includes a heating medium storage portion 20, a heat pump 30, and an LNG flow pipe 40. [

The heating medium storage portion 20 may be formed in a rectangular parallelepiped shape having an open top. The heating medium storage part 20 may have a hollow space therein. For example, the heating medium storage part 20 may be a water tank filled with water.

The first heat transfer medium is accommodated in the heat medium storage unit 20. [ In one example, the first heat transfer medium may be water. The LNG flow pipe 40 may be accommodated in the heating medium storage unit 20 and the LNG flow pipe 40 may be at least partially submerged in the first heat transfer medium.

The first heat transfer medium is heat-exchanged with the heat pump 30 to receive heat from the heat pump 30 and heat exchange with the LNG flow tube 40 to transfer heat to the LNG flow tube 40 . The heat transferred from the first heat transfer medium to the LNG flow pipe 40 may be used as heat for vaporizing LNG in the LNG flow pipe 40.

The first heat transfer medium h1, that is, the water flow tube 21 through which water can pass may be provided on the outer side of the heating medium storage unit 20. [ Both ends of the water flow tube 21 are coupled to the side surface of the heat medium storage part 20 and the water flow tube 21 can extend through the inside of the heat pump 30.

The water inside the heating medium storage portion 20 flows into one end of the water flow tube 21 and the water inside the water flow tube 21 flows into the heating medium storage portion 21 at the other end of the water flow tube 21 20).

The water flowing inside the water flow pipe 21 can be heated by absorbing the heat transmitted from the heat pump 30 while moving from the lower side to the upper side of the water flow pipe 21. The water flow tube 21 can absorb heat from the second heat transfer medium h2, which will be described later, through the heat pump 30. [

The water flowing through the water flow pipe 21 passes through the inside of the heat pump 30 to absorb heat from the heat pump 30, thereby raising the temperature of the water inside the water flow pipe 21. In other words, the temperature of the water flowing out of the water flow tube 21 is higher than the temperature of the water flowing into the water flow tube 21. For example, the temperature of the water flowing into the water flow tube 21 may be 40 ° C, and the temperature of the water flowing out of the water flow tube 21 may be 50 ° C. The reason why the temperature of the water inside the water flow pipe 21 rises is because the water flow pipe 21 receives heat energy from the heat pump 30. The energy received from the heat pump 30 by the water flow pipe 21 is transferred to the LNG flow pipe 40 to be used for vaporizing the natural gas in the liquid state.

A sufficient amount of water may be contained in the heating medium storage part 20 to have sufficient heat energy to vaporize the liquid natural gas passing through the inside of the LNG flow pipe 40. The heating medium storage unit 20 can receive water such that most of the LNG flow pipe 40 can be locked.

The heat pump 30 can receive seawater from the sea. One side of the heat pump 30 is provided with a seawater inlet pipe s1 through which the seawater s can flow and a seawater discharge pipe s2 through which the seawater s introduced into the heat pump 30 can be discharged do.

The seawater (s) introduced through the seawater inlet pipe (s1) can be used as a heat source supplied to the heat pump (30). Seawater (s) is natural energy, and seasonal fluctuation of temperature is less than river water, and freezing temperature is low, so it is easy to use as a low temperature heat source. That is, the heat pump 30 has excellent characteristics as a heat source.

The seawater s introduced into the heat pump 30 through the seawater inlet pipe s1 can perform heat exchange with the second heat transfer medium h2 flowing in the heat pump 30. [ The seawater s introduced into the heat pump 30 through the seawater inlet pipe s1 can transfer heat to the second heat transfer medium h2. The temperature of the seawater s introduced into the heat pump 30 through the seawater inlet pipe s1 is lower than the temperature of the seawater s flowing out from the heat pump 30 through the seawater outlet pipe s2, Lt; / RTI > For example, the temperature of the seawater s introduced into the heat pump 30 through the seawater inlet pipe s1 may be approximately 5 ° C, and the temperature of the seawater s flowing out from the heat pump 30, RTI ID = 0.0 > 1 C. < / RTI > The seawater (s) can be heat-exchanged with an evaporator (31) to be described later and can be heated by the evaporator (31). The heat transfer in the evaporator 31 will be described later in detail.

On the other hand, the water flow tube 21 of the heat medium storage unit 20 may be coupled to the other side of the heat pump 30. The water flow tube 21 may be coupled with the heat pump 30 to enable heat exchange with the second heat transfer medium h2 as described above. The water flowing through the water flow pipe 21 can be heat-exchanged with a condenser 33 to be described later to absorb heat in the condenser 31. The heat transfer in the condenser 33 will be described later in detail.

The heat pump 30 absorbs heat from the seawater and can transfer the heat absorbed from the seawater to the water flowing through the water flow tube 21. [ The heat pump 30 includes the evaporator 31, the compressor 32, the condenser 33, and the expansion valve 34, although the temperature of the seawater is lower than the temperature of the water flowing through the water flow pipe 21. However, Heat can be transferred from the seawater to the water flow tube 21 using a refrigerant cycle.

The compressor (32) may serve to pressurize the second heat transfer medium (h2) in a high-temperature, high-pressure gas state. The pressurized second heat transfer medium (h2) may be transferred to the condenser (33).

The compressor (32) includes a power unit (not shown) for compressing the second heat transfer medium (h2), and the heat transfer medium (h2) Can be converted. The power unit may be determined in consideration of a temperature condition and a mechanical efficiency of the second heat transfer medium h2 transferred to the compressor 32. For example, a motor may be used as the power unit.

The condenser 33 takes heat from the second heat transfer medium h2 of high temperature and high pressure discharged from the compressor 32 and condenses the second heat transfer medium h2. The heat of the second heat transfer medium (h2) in the condenser (33) can be transferred to the water inside the water flow pipe (21). The water flow pipe 21 may be installed adjacent to the condenser 33 inside the heat pump 30 and the heat of the condenser 33 may be transferred to the water flow pipe 21. [

In other words, the water of the water flow pipe 21 flowing adjacent to the condenser 33 can be heated by absorbing the heat of the second heat transfer medium h2.

The water inside the water flow pipe 21 can be introduced into the heat medium storage unit 10 after absorbing heat from the condenser 33.

The condenser 33 discharges the heat and transfers it to the water flow tube 21. The second heat transfer medium h2 transferred from the compressor 32 in a high temperature and high pressure gaseous state is returned to the low temperature and high pressure It can be liquefied in a liquid state.

The expansion valve 34 may control the flow rate of the second heat transfer medium h2 by lowering the pressure of the second heat transfer medium h2 by a throttling action or the like.

The expansion valve 34 may serve to reduce the pressure of the second heat transfer medium h2 condensed in the condenser 33 to an evaporative state.

The second heat transfer medium (h2) transferred to the expansion valve (34) can be moved to the evaporator (31) again with low temperature and low pressure liquid and gaseous state.

In the evaporator 31, the low-temperature, low-pressure liquid and the gaseous second heat transfer medium h2 can evaporate and absorb ambient heat. The second heat transfer medium h2 evaporated in the evaporator 31 can absorb heat from seawater s flowing around the evaporator 31 while evaporating. Since the evaporator 31 is in direct contact with the seawater s, the evaporator 31 may be formed of at least titanium to prevent corrosion due to seawater salinity.

The evaporator 31 uses the seawater s as a low heat source and the seawater s is supplied through the seawater inlet pipe s1 and the low temperature seawater s, May be discharged to the sea water discharge pipe (s2).

In order to sufficiently absorb heat from the sea water (s) used as a low-temperature heat source, the inside of the evaporator (31) is provided with a plate-type or hollow- (Shell and Tube type). The second heat transfer medium (h2) absorbing heat from the evaporator (31) can be sent to the compressor (32) as a high temperature, low pressure gas.

As a result, the second heat transfer medium (h2) circulates inside the heat pump (31) by the heat of the seawater (s) absorbed by the evaporator (31) , The water inside the heating medium storage portion 20 that has absorbed the discharged heat can be heated. In other words, due to the continuous action of the heat pump 30, heat flow occurs between the water inside the heating medium storage portion 20 and the liquefied natural gas (LNG) inside the LNG flow pipe 40, As a result, the natural gas in the liquid state can be vaporized by the natural gas in the gaseous state.

The heat pump 30 may be installed on a beach near a power plant. In this case, the heat pump 30 is connected to the heat pump 30 through the heat pump 30, The heat transfer medium h2 can be heated. In addition, it is possible to preheat the seawater (s) used as a heat source of the heat pump (30) by using the warm water. The temperature of the common water discharged from the power plant to the sea is 20 ° C to 40 ° C, whereas the temperature of ordinary seawater is about 5 ° C. The use of the hot water discharged from the power plant as the seawater flowing into the heat pump 30 can solve the problem of disposal of the hot water discharged from the power plant. In addition, by transmitting a larger amount of heat to the second heat transfer medium (h2) in the heat pump (30), the efficiency of the heat pump (30) using heat exchange efficiency and seawater as a heat source can be improved.

When the high-temperature heat discharged by the heat pump 30 heats the water passing through the inside of the water flow pipe 21, the LNG flow pipe 40 provided inside the heating medium storage unit 20, Heat transfer occurs between the water.

The LNG flow pipe (40) may be provided inside the heating medium storage part (20). The LNG flow pipe 40 may be locked to the first heat transfer medium h1 received in the heat medium storage unit 20. [ When the first heat transfer medium h1 provided in the heating medium storage unit 20, that is, the water, is heated, heat transfer occurs to the LNG flow tube 40.

The natural gas in the liquid state can be introduced into the lower portion of the LNG flow tube 40, and the natural gas in the liquid state can be moved from the lower portion to the upper portion of the LNG flow tube 40. Since the vaporization point of the liquid natural gas passing through the inside of the LNG flow pipe 40 is approximately -170 ° C. and the general temperature of the first heat transfer medium h 1 is 40 ° C. to 50 ° C., The first heat transfer medium (h1) and the second heat transfer medium (h1).

The natural gas in the liquid state can be vaporized into natural gas by the heat transferred from the first heat transfer medium h1 to the LNG flow pipe 40 while the natural gas in the liquid state flows in the LNG flow pipe 40. [

The LNG flow tube 40 may be formed in a hollow cylindrical shape. The LNG flow tube 40 may be bent and bent several times so that heat transfer can be effectively performed. That is, the LNG flow pipe 40 may extend horizontally, be bent and extend vertically, and horizontally extend again.

In addition, the diameter and thickness of the LNG flow pipe 40 may be variously formed, and may be formed of at least one of copper and stainless steel so that heat transfer can be performed well.

4 is a flowchart of a liquefied natural gas vaporization method according to an embodiment.

Referring to FIG. 4, in the liquefied natural gas vaporizing method according to an embodiment, seawater (s) is first introduced into the heat pump 30 from the sea (S10). The seawater (s) may be introduced into the seawater inlet pipe (s1) provided in the heat pump (30).

The seawater s introduced into the heat pump 30 transfers heat to the second heat transfer medium h2 circulating in the heat pump 30 and is discharged to the sea water discharge pipe s2 (S20). The seawater s introduced into the heat pump 30 flows around the evaporator 31 provided in the heat pump 30 and the evaporator 31 can absorb heat from the seawater s .

Then, the water storage tank 20 is filled with water (S30), and the LNG storage tank 20 is submerged in the water storage tank 20 (S40).

Then, the second heat transfer medium (h2) inside the heat pump (30), which receives heat from the seawater, can heat the water by transferring heat to the water in the heat medium storage part (20) S50).

Then, the natural gas in the liquid state may be introduced into the LNG flow pipe 40 (S60). The natural gas in the liquid state flows into the lower portion of the LNG flow pipe 40 and can move upward from the lower portion of the LNG flow pipe 40.

Lastly, heat transfer occurs between the water inside the heating medium storage part 20 and the LNG flow tube 40, and the heat of the water is transferred to the LNG flow tube 40, Natural gas can be vaporized (S70).

5 is a schematic view of a liquefied natural gas vaporizer according to another embodiment of the present invention.

Referring to FIG. 5, in the liquefied natural gas vaporizer 11 according to the present embodiment, the heat pump is controlled in stages by the temperature of the heating medium storage part 20, and the temperature difference of the seawater flowing into and out of the heat pump 1 to 4 in that the flow rate of the seawater flowing into the heat pump is controlled and the flow rate of the water flowing into the heat medium storage unit due to the temperature difference of the first heat transfer medium flowing into and out of the heat medium storage unit is controlled, There is a difference in the above-described embodiment.

In addition to the above, contents overlapping with the above-described embodiment, such as a feature of vaporizing liquefied natural gas using a heat pump using seawater as a heat source, etc., will be used for the contents of the above embodiments.

The liquefied natural gas vaporizer 11 according to the present embodiment further includes a water tank temperature sensor 22, a modular heat pump 50, a seawater circulation pump 60 and a heat medium circulation pump 70 .

The water tank temperature sensor 22 can sense the temperature of the first heat transfer medium h1 provided in the heating medium storage unit 20. [ The water tank temperature sensor 22 can control the operation of the modular heat pump 50 based on the temperature of the first heat transfer medium h1, i.e., water.

Further, a controller (not shown) for controlling the modular heat pump 50 may be further provided. The controller receives temperature information from the water tank sensor 22 and controls the operation of the modular heat pump 50 based on the temperature information.

The modular heat pump 50 may include a plurality of heat pumps. A plurality of heat pumps included in the modular heat pump 50 may all operate, or only a part thereof may operate.

In one example, the modular heat pump 50 may include four heat pumps, and the modular heat pump 50 may include a first heat transfer medium h1 sensed by the water bath temperature sensor 22 , It is possible to operate all of the heat pumps included in the modular heat pump 50, and to operate only some of them. That is, the modular heat pump 50 may operate only one heat pump or all of the four heat pumps depending on the temperature of the first heat transfer medium h1.

The modular heat pump 50 may serve to transfer the heat of the seawater S to the first heat transfer medium h1. In detail, the heat of the seawater S is transferred to the second heat transfer medium h2, and the heat of the second heat transfer medium h2 is transferred to the first heat transfer medium h1 again.

Therefore, the greater the number of heat pumps operated by the modular heat pump 50, the more heat is transferred from the seawater S to the first heat transfer medium h1, The smaller the number of the heat pumps, the smaller the heat transmitted from the seawater S to the first heat transfer medium h1.

The modular heat pump 50 can reduce the number of heat pumps to be operated when the temperature of the water contained in the heating medium storage portion 20 rises to a temperature sufficient to vaporize the liquefied natural gas with natural gas. For example, when the temperature of the water measured by the water tank temperature sensor 22 rises above a preset temperature and LNG vaporization occurs sufficiently, the control unit controls one of the heat pumps included in the modular heat pump 50 Can be operated.

On the other hand, if the temperature of the water contained in the heating medium storage portion 20 is low enough to vaporize the liquefied natural gas, the modular heat pump 50 can increase the number of the heat pumps to be operated. For example, when the temperature of the water measured by the water tank temperature sensor 22 drops below a predetermined temperature and the LNG is not sufficiently vaporized, the control unit controls the heat pump (not shown) Can be operated.

Accordingly, the operation of the unnecessary heat pump can be reduced according to the fluctuation of the vaporized amount of the liquefied natural gas, so that the energy and the cost can be saved, and the performance of the heat pump can be maintained optimally.

Meanwhile, the seawater circulation pump 60 can increase the seawater to flow seawater into the modular heat pump 50.

The modular heat pump 50 includes a seawater temperature difference sensor 65 for measuring a temperature difference between the temperature of the seawater flowing into the modular heat pump 50 and the temperature of the seawater flowing out of the modular heat pump 50 .

The seawater circulation pump 60 can be controlled by the temperature of the incoming seawater and the temperature difference of the seawater passing through the modular heat pump 50 to transfer the heat.

More specifically, when the temperature difference measured by the seawater temperature difference sensor 65 is decreased, the heat transferred to the thermal medium storage unit 20 is reduced. This means that the thermal medium storage unit 20 is a liquefied natural It means that it has enough heat to liquefy the gas. Therefore, in this case, it is necessary to reduce the amount of seawater flowing into the modular heat pump 50, so that the number of revolutions of the seawater circulation pump 60 can be reduced.

On the contrary, when the temperature difference measured by the seawater temperature difference sensor 65 increases, the heat transferred to the thermal medium storage unit 20 increases. This means that the thermal medium storage unit 20 is a liquefied natural Which means that more heat is needed to liquefy the gas. Therefore, in this case, it is necessary to increase the amount of seawater flowing into the modular heat pump 50, so that the number of revolutions of the seawater circulation pump 60 can be increased.

The water flow tube 21 for introducing and discharging the first heat transfer medium h1 into the modular heat pump 50 is provided with a heat medium circulation path h1 for supplying the first heat transfer medium h1 to the heat medium storage part 20, A pump 70 may be provided.

The heat medium circulation pump 70 can supply the first heat transfer medium h1 whose temperature has been raised via the modular heat pump 50 to the inside of the heating medium storage part 20. [ The first heat transfer medium (h1) with the raised temperature can vaporize the liquefied natural gas passing through the LNG flow tube.

The water flow pipe 21 is provided with a first heat transfer medium h1 and a second heat transfer medium h1. The water flow tube 21 is connected to the first heat transfer medium h1, And a water temperature difference sensor 75 for measuring the water temperature difference.

The heat medium circulation pump 70 is connected to the first heat transfer medium h1 and the second heat transfer medium h1 through the first heat transfer medium h1 and the second heat transfer medium h1, Can be controlled by difference.

More specifically, when the temperature difference measured by the water temperature difference sensor 75 decreases, the heat transferred to the thermal medium storage unit 20 is reduced. This means that the thermal medium storage unit 20 is liquefied It means that it has sufficient heat to liquefy natural gas. Therefore, in this case, it is necessary to reduce the amount of the first heat transfer medium h1 flowing into the heat medium storage unit 20, so that the rotational frequency of the heat medium circulation pump 70 can be reduced.

On the contrary, when the temperature difference measured by the water temperature difference sensor 75 increases, the heat transferred to the thermal medium storage unit 20 increases, which means that the thermal medium storage unit 20 is liquefied natural Which means that more heat is needed to liquefy the gas. Therefore, in this case, it is necessary to increase the amount of the first heat transfer medium h1 flowing into the heat medium storage unit 20, so that the number of revolutions of the heat medium circulation pump 70 can be increased.

In this way, the unnecessary number of revolutions of the heat medium circulation pump 70 and the seawater circulation pump 60 is reduced in a situation where the liquefied natural gas is sufficiently liquefied, whereby power consumption can be minimized.

For reference, the pump power P after control is _{equal to} the pump power P ₀ before control (the number of revolutions after control / the number of revolutions before control) multiplied by ³ .

(P는 제어 후의 펌프 동력, P₀는 제어 전의 펌프 동력)In other words,

(P is the pump power, P ₀ is the power before the pump control after the control)

에 비례하여 소비 전력을 줄일 수 있는 효과가 있는 것이다.
Therefore, by reducing the number of rotations of the pump,

The power consumption can be reduced in proportion to the power consumption.

1, 10: Liquefied natural gas vaporizer 2: Heat medium storage unit
3: Burner 4: LNG flow tube
5: Exhaust gas outlet 10: Liquefied natural gas vaporizer
20: storage part 21: water flow tube
22: water tank temperature sensor 30: heat pump
31: Evaporator 32: Compressor
33: condenser 34: expansion valve
40: LNG flow tube 50: Modular heat pump
60: First seawater circulation pump 70: Heat medium circulation pump
h1: first heat transfer medium h2: second heat transfer medium
s: seawater s1: seawater inflow pipe
s2: Seawater discharge pipe

Claims (4)

A heating medium storage portion in which the first heat transfer medium is stored;
A water tank temperature sensor for measuring a temperature of the first heat transfer medium stored in the heat medium storage unit;
A modular heat pump having one side receiving heat from seawater and the other side transmitting heat to the first heat transfer medium and having a plurality of heat pumps;
A seawater temperature difference sensor for measuring a temperature difference between seawater introduced into the modular heat pump and seawater discharged through the modular heat pump;
A seawater circulation pump for introducing seawater into the modular heat pump and controlling the amount of seawater flowing into the modular heat pump according to the temperature difference measured by the seawater temperature difference sensor;
A heat medium temperature difference sensor for measuring a temperature difference between a first heat transfer medium discharged from the heat medium storage unit and flowing into the modular heat pump and a first heat transfer medium discharged from the modular heat pump and then introduced into the heat medium storage unit, ;
The first heat transfer medium discharged from the heat medium storage unit and having passed through the modular heat pump is introduced into the heat medium storage unit again and the first heat transfer member is introduced into the heat medium storage unit by the temperature difference measured by the heat medium temperature difference detection sensor. A heating medium circulation pump for controlling the amount of the medium; And
At least a portion of which is accommodated in the heating medium storage portion, exchanges heat with the first heat transfer medium, and introduces a natural gas in a liquid state;
Wherein the liquefied natural gas vaporizing device comprises:
The method according to claim 1,
And stops the operation of a part of the heat pump included in the modular heat pump when the temperature of the water tank sensor becomes high.
The method according to claim 1,
Wherein the number of revolutions of the seawater circulation pump decreases when the temperature difference measured by the seawater temperature difference detecting sensor becomes small and the number of revolutions of the heat medium circulation pump decreases when the temperature difference measured by the heat medium temperature difference detecting sensor becomes small.
The method according to claim 1,
The modular heat pump is located near a power plant, and the modular heat pump preheats the seawater used as the heat source of the modular heat pump by using the hot water discharged from the power plant as a heat source or using the hot water. Wherein the liquefied natural gas vaporizer is a liquefied natural gas.

Images