JPH07139370A - Method and device for gasifying and feeding liquefied natural gas - Google Patents

Abstract

PURPOSE:To prevent discharge of cooling discharge water to sea, to prevent the occurrence of closure of a piping owing to adhesion and growth of organisms on a pipe wall, further to suppress corrosion of a heat transfer pipe, and additionally to prevent lowering of a combustion gas turbine output owing to the increase of an atmospheric temperature during a summer season. CONSTITUTION:A steam turbine 62 mechanism is provided with a condenser 63 mechanism to restore steam after use to water. A carburetor 1 is provided to heat-exchange Liquefied natural gas 1a fed from the outside of a system with a first heating medium 1b circulating a first circulation route L1 formed in the system to gasify the liquefied natural gas 1a into natural gas 1a' for fuel. A first heat-exchanger 41 is located in a first circulation route L1. A second circulation route L5 through which a second heating medium if is circulated is formed between the first heat-exchanger 41 and the condenser 63 and heat-exchange of steam 1d fed to the condenser 63 trough the second heating medium 1f with the first heating medium 1b fed to the second heat-exchanger 41 is practicable.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for vaporizing and supplying liquefied natural gas supplied as a fuel for steam power generation or combined power generation. By applying the present invention, the steam power generation or It is possible to effectively remove the exhaust heat of the condenser in the combined cycle power generation, and it is possible to recover the output at the summer temperature rise in the combined cycle power plant.

[0002]

2. Description of the Related Art So-called gas turbine power generation, in which a turbine is rotated by a gas flow of combustion gas to generate electric power, is a type of thermal power generation, and a power of up to several hundred thousand KW is usually applied for peak load or emergency. There is. A power generation method that uses combustion gas and steam obtained from a boiler in combination is commonly called so-called combined power generation, and this new power generation method, combined power generation, is a combination of a combustion gas turbine mechanism and a steam turbine mechanism. It makes it easy to start / stop and adjust the load.
Since the thermal efficiency is higher than that of steam power generation using only a steam turbine, it is promising as a useful power generation method in the future, and a large-scale power generation system of 1 million KW class has now appeared. Further, gas turbine power generation that uses liquefied natural gas, which is a clean fuel, has become the mainstream in recent years.

In countries and regions where energy demand is expected to grow in the future, it is necessary to secure an increasingly stable energy source as well as to protect the global environment. Therefore, it is considered that the importance of combined power generation using liquefied natural gas as a fuel, which has a huge reserve and can be stably secured in the future and is a clean energy source, will increase further.

On the other hand, in Japan, most of the liquefied natural gas is imported from abroad by a large-scale dedicated ship, stored in a cold storage tank, and then appropriately pumped and used. And since the pumped out is a low temperature liquid,
This must be vaporized and used for combustion. Therefore, a vaporizer is always installed in a power plant that uses liquefied natural gas as a fuel.

By the way, since the amount of liquefied natural gas used in a power plant is enormous, a large amount of heat source commensurate with the enormous amount of liquefied natural gas is required to vaporize it. Conventionally, such a large amount of heat source depends on seawater, and the liquefied natural gas is vaporized by exchanging heat between the taken seawater and the liquefied natural gas.

FIG. 2 is a perspective view showing an example of such a vaporizer, which is a so-called open rack type vaporizer (hereinafter referred to as OR).
It is called V10). This ORV10
A lower header 11 arranged in a horizontal direction as illustrated in FIG. A large number of heat transfer tubes 12 are connected to the lower header 11, and the heat transfer tubes 12 are connected to the upper header 13 at their upper portions. Then, liquefied natural gas (hereinafter referred to as LNG1a) is supplied to the heat transfer tube 12 from the lower header 11 and is led out from the upper header 13.

[0007]

By the way, the conventional OR
In the LNG vaporizer represented by V10, LNG1
Since an enormous amount of heat source is required to vaporize a, seawater, which exists inexhaustibly as described above, has been used to cover this enormous amount of heat source. Caused the following problems.

[0008] First, a large amount of seawater is heat-exchanged with the low-temperature LNG1a in the LNG vaporizer, and as a result, a large amount of cold drainage is generated, and this cold drainage is returned to the sea. However, environmental problems such as changes in the ecosystem and changes in the ecosystem may occur, and problems such as fishery compensation problems may be raised due to the decrease in catches in the sea area. In order to eliminate such inconvenience, seawater intake may be restricted as appropriate, but due to insufficient intake heat source for heat exchange, it is not possible to vaporize a sufficient amount of LNG1a. In the end, this leads to the problem that power cannot be generated sufficiently.

Further, when seawater is taken in as the heat medium 1b, organisms such as barnacles and mussels living in the sea are introduced into the intake pipe, and they adhere to the wall of the pipe to reproduce and flow in the seawater. Therefore, there is a problem in that they must be removed regularly, which requires a lot of manpower, time and cost.

Further, since the outer peripheral surface of the heat transfer tube 12 is covered with the chemically active seawater, the heat transfer tube 12 is very likely to corrode, which not only shortens the life of the heat transfer tube 12 but also eliminates it. However, it requires a lot of manpower, time and cost for maintenance.

In addition, since the seawater for heating LNG1a has a low temperature in winter, there is a problem that the seawater cannot be efficiently used as a heat source for vaporizing LNG1a in winter.

The present invention has been made in order to solve the above-mentioned problems. First, cold drainage is not released to the sea, and the clogging of the pipe due to the adherent growth of living organisms on the pipe wall is prevented. An object of the present invention is to provide a method and apparatus for vaporizing and supplying liquefied natural gas that does not generate corrosion, suppresses corrosion of heat transfer tubes, and can effectively absorb the influence of seasonal fluctuations.

[0013]

The method for vaporizing and supplying liquefied natural gas according to claim 1 of the present invention is a steam power generation facility equipped with a steam turbine mechanism for driving a turbine with steam obtained from a boiler, or Vaporize liquefied natural gas supplied as fuel to a combined power generation facility that is equipped with a steam power generation facility and a combustion gas turbine mechanism that drives a turbine with combustion gas obtained by burning liquefied natural gas without using seawater. A method for vaporizing and supplying liquefied natural gas, wherein the first heat medium for heat of vaporization is circulated and supplied to a vaporizer for vaporizing the liquefied natural gas into natural gas for fuel, and the steam power is used. A second heat medium for cooling, which returns steam to water, is circulated and supplied to a condenser provided in a power generation facility through a second circulation path, and the first circulation path and the second circulation path. In the first heat exchanger provided across second heat medium is cooled, and is characterized in heating the first heat medium.

A method for vaporizing and supplying liquefied natural gas according to a second aspect of the present invention is the method for vaporizing and supplying liquefied natural gas according to the first aspect, wherein the first circulation path immediately after the vaporizer and the first immediately before the vaporizer. A recycle path is provided between the recycle path and the recycle path, and is configured to control the flow rate of the heat source medium that vaporizes the liquefied natural gas by adjusting the flow rate of the first heat medium that is recirculated to this recycle path. It is characterized by.

The method for vaporizing and supplying liquefied natural gas according to claim 3 of the present invention is the method for vaporizing and supplying liquefied natural gas according to claim 1 or 2, wherein the downstream side of the vaporizer and the first heat exchanger are connected to each other. The first circulation path between the upstream side is provided with a withdrawal path that branches from the first circulation path and joins with the first circulation path on the downstream side, and this withdrawal path is provided with a second heat exchanger. On the downstream side of the second heat exchanger, a bypass path is formed that connects the drawing path and the first circulation path on the upstream side of the vaporizer, which is on the downstream side of the first heat exchanger, and the second heat exchange is performed. In the vessel, heat exchange between the first heat medium and the air for the combustion gas turbine is performed to cool the air.

The method for vaporizing and supplying liquefied natural gas according to claim 4 of the present invention is the method for vaporizing and supplying liquefied natural gas according to claim 1, 2 or 3, wherein the first circulation upstream of the vaporizer circulation path. The passage is provided with a start-up boiler that supplies a vaporization heat source for vaporizing liquefied natural gas at the time of start-up.

The method for vaporizing and supplying liquefied natural gas according to claim 5 of the present invention is the method for vaporizing and supplying liquefied natural gas according to claim 1, 2, 3 or 4, wherein the vaporizer is an open rack type vaporizer or It is characterized in that it is an intermediate medium type multi-tube heat exchanger.

A liquefied natural gas vaporization and supply device according to a sixth aspect of the present invention is a steam generator equipped with a steam turbine mechanism for driving a turbine with steam obtained from a boiler, or the steam generator and the liquefied natural gas. A vaporization supply device for liquefied natural gas applied to a combined cycle power generation facility that is equipped with a combustion gas turbine mechanism that drives a turbine with combustion gas obtained by burning gas, and is used for the steam turbine mechanism. A condenser for returning the later steam to water is provided, and liquefied natural gas supplied from outside the system and the first heat medium circulating in the first circulation path formed in the system are heat-exchanged to make the liquefied natural gas. A vaporizer for vaporizing gas into natural gas for fuel is provided, a first heat exchanger is provided in the first circulation path, and a second heat medium is provided between the first heat exchanger and the condenser. Is circulated A second circulation path is formed to perform heat exchange between the steam supplied to the condenser via the second heat medium and the first heat medium supplied to the second heat exchanger. It is characterized by being configured as follows.

A liquefied natural gas vaporization and supply device according to a seventh aspect of the present invention is the liquefied natural gas vaporization and supply device according to the sixth aspect, wherein the first circulation path immediately after the vaporizer and the first vaporization device immediately before the vaporizer. A recycle path is provided between the recycle path and the recycle path, and is configured to control the flow rate of the heat source medium that vaporizes the liquefied natural gas by adjusting the flow rate of the first heat medium that is recirculated to this recycle path. It is characterized by.

A liquefied natural gas vaporization and supply device according to an eighth aspect of the present invention is the liquefied natural gas vaporization and supply device according to the sixth or seventh aspect, in which the downstream side of the vaporizer and the first heat exchanger are connected. The first circulation path between the upstream side is provided with a withdrawal path that branches from the first circulation path and joins with the first circulation path on the downstream side, and this withdrawal path is provided with a second heat exchanger. On the downstream side of the second heat exchanger, a bypass path is formed that connects the drawing path and the first circulation path on the upstream side of the vaporizer, which is on the downstream side of the first heat exchanger, and the second heat exchange is performed. In the vessel, heat exchange between the first heat medium and the air for the combustion gas turbine is performed to cool the air.

A liquefied natural gas vaporization and supply device according to a ninth aspect of the present invention is the liquefied natural gas vaporization and supply device according to the sixth, seventh or eighth aspect, wherein the first circulation on the upstream side of the vaporizer circulation path. The passage is provided with a start-up boiler that supplies a vaporization heat source for vaporizing liquefied natural gas at the time of start-up.

A liquefied natural gas vaporization and supply device according to a tenth aspect of the present invention is the method for vaporizing and supplying liquefied natural gas according to the sixth or seventh aspect, wherein the vaporizer is an open rack type vaporizer or It is characterized in that it is an intermediate medium type multi-tube heat exchanger.

[0023]

According to the method and apparatus for vaporizing and supplying liquefied natural gas according to claim 1 or 6, the first heat medium used for vaporizing the liquefied natural gas in the vaporizer is in the first circulation path. Since the water is circulated and used, the conventionally taken seawater is not returned to the sea as cold drainage due to heat exchange, and the environmental deterioration due to cold drainage can be effectively suppressed. Further, there is no obstruction in the pipe due to the propagation of marine organisms in the intake pipe, etc. due to the intake of seawater. Also, since seawater is not used, corrosion inside the pipe is effectively suppressed.

The liquefied natural gas supplied from outside the system receives heat from the heat medium by heat exchange with the first heat medium in the vaporizer and is vaporized into natural gas, which is then supplied to the boiler, turbine or the like. In addition, even if the first heat medium is low in temperature in the winter due to the influence of the outside air temperature, the second heat medium is circulated in the second circulation system to move the first heat exchanger. It is possible to raise the temperature of the first heat medium through the above, and it is possible to eliminate the disadvantage that the liquefied natural gas is not vaporized properly due to the low temperature of the first heat medium.

According to the method and apparatus for vaporizing and supplying liquefied natural gas according to claim 2 or 7, there is a recycling route between the first circulation route immediately after the vaporizer and the first circulation route immediately before the vaporizer. Since it is provided, by adjusting the flow rate of the first heat medium to be recirculated to this recycling path, when the carburetor is an open rack type, it prevents the water film from running out causing damage to the equipment, When the vaporizer is an intermediate medium type multitubular heat exchanger, it is possible to easily prevent ice accretion in the thin tubes.

According to the method or apparatus for vaporizing and supplying liquefied natural gas according to the third or eighth aspect, by supplying the first heat medium to the drawing path, the second heat exchanger attached to this path. In the above, since the heat of the first heat medium cooled by the heat of the vaporizer and the air are cooled, the supply amount of air to the combustion gas turbine is increased and the output of the turbine is increased. You can

According to the method and apparatus for vaporizing and supplying liquefied natural gas according to claim 4 or 9, the liquefied natural gas for vaporizing the liquefied natural gas at start-up is provided in the first circulation path upstream of the vaporizer circulation path. Since a startup boiler that supplies a heat source for vaporization is provided, liquefied natural gas is vaporized by the vaporization heat source supplied from the startup boiler even when the heat balance of the entire system is not yet formed at startup, and is supplied as fuel. It is possible to operate the power plant. When the heat balance of the entire system becomes stable, the operation of the start-up boiler should be stopped.

According to the method and apparatus for vaporizing and supplying liquefied natural gas according to the fifth or tenth aspect, since an open rack type vaporizer or an intermediate medium type multi-tube heat exchanger is used as the vaporizer, it is opened. In the case of the open rack type vaporizer of the type, since the first heat medium receives the cold heat from the liquefied natural gas and is frozen, only an ice accretion layer is formed on the outer surface of the vaporizer, and there is no hindrance to the operation. Freezing does not damage the equipment. Further, in the case of the intermediate medium type multi-tube heat exchanger, the heat transfer efficiency is excellent, and the liquefied natural gas can be vaporized more effectively.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a system diagram for explaining a method and apparatus for vaporizing and supplying liquefied natural gas according to the present invention. In this figure, of the combined power generation equipment, only the portion of the steam power generation equipment that occupies an important position in the configuration of the present invention is shown, and the portion related to the combustion gas turbine mechanism is omitted.

The liquefied natural gas vaporization supply device according to the present invention is a steam power generation facility equipped with a steam turbine mechanism for driving a turbine with steam obtained from a boiler, or burns liquefied natural gas with the steam power generation facility. It is a liquefied natural gas vaporization and supply device applied to a combined cycle power generation facility in which a combustion gas turbine mechanism for driving a turbine by the combustion gas obtained as described above is provided side by side.

The steam turbine mechanism is provided with a condenser 63 for returning steam after use to water, and LNG (liquefied natural gas) 1a supplied from outside the system and a first circulation path formed in the system. The first heat medium 1b circulating L1 is heat-exchanged with the first heat medium 1b so that the LNG1a is NG (natural gas) for fuel.
A vaporizer 1 for vaporizing 1a 'is provided. A first heat exchanger 41 is provided in the first circulation path L1, and a second circulation path L5 for circulating the second heat medium 1f is formed between the first heat exchanger 41 and the condenser 63. Has been done.
In addition, heat is exchanged between the steam 1d supplied to the condenser 63 and the first heat medium 1b supplied to the second heat exchanger 63 via the second heat medium 1f. It is basically composed.

The method and apparatus for vaporizing and supplying liquefied natural gas according to the present invention will be described in detail below with reference to FIG. First, as shown in this figure, L supplied from outside the system
A vaporizer 1 for vaporizing NG1a is provided.
In the present embodiment, the vaporizer 1 employs the ORV (open rack vaporizer) 10 described above with reference to FIG. The first heat medium 1b circulating in the first circulation path L1 is supplied to the vaporizer 1 from above, and LNG
The first heat medium 1b is cooled by heat exchange with 1a, and the LNG 1a is heated and vaporized, and NG (natural gas) 1
It is derived as a '. The NG1a 'derived from the vaporizer 1 is used as a fuel for a boiler 61 of a steam power generation facility or a combustion gas turbine mechanism (not shown).

In this embodiment, the first heat medium 1b is used.
Industrial water is applied as. Industrial water mixed with ethylene glycol, which is an antifreeze, may be used as the first heat medium 1b. Further, in the present embodiment, the ORV 10 is applied as the vaporizer 1, but the vaporizer 1 is not limited to the ORV 10, and a so-called intermediate medium type multitubular type in which heat exchange is performed via the built-in CFC or propane. A heat exchanger may be applied.

A pit 2 for receiving the first heat medium 1b used for heat exchange in the vaporizer 1 is provided below the vaporizer 1, and a recycling path L2 is provided immediately downstream of the pit 2. It is branched. A short circuit circulation pump 31 is provided in the recycling path L2, and a first control valve 51 is provided downstream of the short circuit circulation pump 31.

A temperature controller 71 is provided on the upstream side of the vaporizer 1, and the temperature controller 71 is also provided.
A flow rate controller 72 is provided on the upstream side and downstream of the connection point of the recycling path L2 to the first circulation path L1. The temperature in the first circulation path L1 immediately before the vaporizer 1 is detected by the temperature controller 71, and the first heat medium 1b in the first circulation path L1 immediately before the vaporizer 1 is detected by the flow rate controller 72. The flow rate of is detected. Then, by adjusting the temperature detected by the temperature controller 71 and the set value of the flow controller 72, the opening degree of the first control valve 51 is controlled so that this flow rate becomes a preset flow rate. It has become so.

The tip of the recycle path L2 is connected to the first circulation path L1 on the upstream side of the vaporizer 1.
A circulation pump 32 is provided in the first circulation path L1 downstream of the branch point to the recycling path L2, and a three-way valve 3 is provided downstream thereof.

The withdrawal path L3 is branched from the first circulation path L1 via the three-way valve 3, and the withdrawal path L3.
A second heat exchanger 42 is provided in the middle of 3. The second heat exchanger 42 is for performing heat exchange between the first heat medium 1b moving in the drawing path L3 and the air (gas turbine intake air) 1c supplied to the combustion gas turbine, The air 1c is cooled by this heat exchange. The downstream side of the second heat exchanger 42 is joined to the first circulation path L1 on the downstream side of the three-way valve 3.

Further, the temperature of the air 1c discharged from the second heat exchanger 42 is detected, and when the detected value is equal to or lower than a preset temperature, the first heat medium introduced into the drawing path L3. In order to reduce the flow rate of 1b, the three-way valve 3 is provided with an automatic temperature controller 73 for transmitting an opening degree instruction signal.

Further, a bypass path L4 is branched from a drawing path L3 on the downstream side of the second heat exchanger 42. A valve 52 is provided in the middle of the bypass path L4, and the tip of the bypass path L4 is provided with a first heat exchanger 41 provided in a first circulation path L1 downstream of the confluence of the withdrawal path L3. Circulation path L further downstream of
Connected to 1.

On the other hand, steam power generation equipment for supplying heat to the system for vaporizing the LNG 1a is provided. This steam power generation facility includes a boiler 61 that generates steam 1d, a steam turbine 62 that rotates a turbine with the steam 1d obtained from the boiler 61 to generate electricity, and a steam 1d after use that is derived from the steam turbine 62. It is basically composed of a condenser 63 which is condensed and returned to water. These boiler 61 and steam turbine 6
2 and the condenser 63 are connected by the third circulation path L6.

As the condenser 63, an ordinary heat exchanger is adopted in this embodiment, and the cooling water 1e introduced from the outside of the system and the second heat circulating in the second circulation path L5 described later are moved. By heat exchange between the medium 1f and the steam 1d derived from the steam turbine 62, the steam 1
While d is cooled to be condensed water 1d ', the second heat medium 1f is heated.

The second circulation path L5 includes the first heat exchanger 4
1 and the condenser 63 are formed by connecting them in a ring shape, and the second heat medium 1f inside is circulated and moved between them. The circulation pump 33 is provided at an appropriate place in such a second circulation path L5, and the operation of this circulation pump 33 causes the second heat medium 1f to circulate in the second circulation path L5. In this embodiment, industrial water is applied to the second heat medium 1f as well as the first heat medium 1b.

A bypass path L5 'is provided between the downstream side of the condenser 63 and the downstream side of the first heat exchanger 41, and the second control valve 53 is provided in the bypass path L5'. ing. On the other hand, on the downstream side of the first heat exchanger 41, the first heat medium 1 in the first circulation path L1 immediately after the first heat exchanger 41 is provided.
A temperature controller 74 is provided which detects the temperature of b and transmits an opening degree instruction signal of the second control valve 53 according to the detected value.

The set temperature of the first heat medium 1b in the first circulation path L1 immediately after the first heat exchanger 41 is input to the temperature controller 74 in advance, and when the detected temperature is higher than this set temperature. A signal to increase the opening degree of the second control valve 53 and decrease the opening degree of the second control valve 53 in the opposite case is transmitted from the temperature control meter 74 to the second control valve 53.

Therefore, when the temperature of the first heat medium 1b is higher than the set temperature, a larger amount of the second heat medium 1f circulates through the bypass path L5 ', and the first heat exchanger 4
Since the amount supplied to 1 decreases, the amount of heat applied to the first heat medium 1b decreases and the temperature of the first heat medium 1b drops. On the contrary, when the temperature of the first heat medium 1b is lower than the set temperature, the opening degree of the second control valve 53 is reduced and the second heat medium 1f
Since the supply amount to the first heat exchanger 41 increases, the temperature of the first heat medium 1b rises.

A start-up boiler 8 is provided near the first circulation path L1. The startup boiler 8 supplies a heat source necessary for vaporizing the LNG 1a only when the vaporization operation of the LNG 1a by the vaporizer 1 is started and only when the heat balance in the system has not reached a steady state. This is because a normal small boiler is applied.

A route L8 for deriving steam 1g from the startup boiler 8 is provided,
The route L8 is connected between the confluence of the bypass route L4 of the first circulation route L1 and the confluence of the recycling route L2. Therefore, at the time of initial activation of the vaporization heat source system, 1 g of steam generated in the startup boiler 8
Is introduced into the first circulation path L1 via the path L8,
The first heat medium 1b mixed with the first heat medium 1b to raise its temperature, and the temperature of the first heat medium 1b, which has been raised, passes through the first circulation path L1 to the vaporizer 1
It is introduced into the LNG1a and used as a heat source for vaporization of LNG1a.
When the heat balance of the circulating first heat medium 1b reaches a steady state, the operation of the startup boiler 8 is stopped.

It should be noted that instead of directly introducing the steam 1g generated in the start-up boiler 8 into the first circulation path L1 as described above, a new heat exchanger is newly installed on the path L1 and this heat exchanger is installed. Alternatively, the heat of the steam 1g may be supplied to the first heat medium 1b in the first circulation path L1.

Since the method and apparatus for vaporizing and supplying liquefied natural gas according to the present invention are constructed as described above, first of all, the first circulation path L1 is required to start up the vaporization heat source system.
The circulation pump 32 provided in is operated to circulate and move the first heat medium 1b in the first circulation path L1.

However, the heat balance in the system is not in a steady state immediately after startup, and the first heat medium 1b immediately before the vaporizer 1 is still at a temperature sufficient to vaporize the LNG 1a. Has not reached Therefore, for a certain period of time immediately after startup, steam 1g generated by operating the startup boiler 8 is flowed to the first circulation path L1 via the path L8. By doing so, the first heat medium 1b immediately before the vaporizer 1 circulatingly moving in the first circulation path L1 is heated, and can serve as a heat source necessary for vaporizing the LNG 1a. And LNG from outside the system
LNG1a is introduced into vaporizer 1 via conduit L0. The operation of the start-up boiler 8 is stopped when the heat balance in the system reaches a steady state after a certain period of time has passed.

When the heat balance in the system reaches a steady state, the steam 1d generated in the boiler 61 in the steam power generation system circulates in the third circulation path L6. Then, first, the steam turbine 62 is driven to generate electric power, and the used steam 1d is introduced into the condenser 63, where heat between the steam 1d and the second heat medium 1f circulating and moving in the second circulation path L5 is generated. After the replacement, the condensed water 1d 'is returned to the boiler 61 and the second heat medium 1
Heat f.

The second heat medium 1f heated by the heat exchange with the steam 1g is circulated in the first heat exchanger 41 through the first circulation path L1.
Heat is exchanged between and, while cooling itself,
The first heat medium 1b is heated and serves as a heat source for vaporizing the LNG 1a.

Thereafter, the first heat medium 1b heated in the first heat exchanger 41 is introduced into the vaporizer 1, and LNG
Heat is exchanged with LNG1a in the conduit L0, and the heat is cooled and introduced into the pit 2, and at the same time, LNG1
a is vaporized into NG1a ', which is led out of the vaporizer 1 as fuel for power generation. The cooled first heat medium 1b introduced into the pit 2 is again circulated in the first circulation path L1 by driving the circulation pump 32.

Then, in the three-way valve 3 provided in the first circulation path L1, a part of the first heat medium 1b is supplied to the second heat exchanger 42 via the drawing path L3, and this second heat exchange is performed. Is used for heat exchange with the air 1c in the vessel 42,
The air 1c is cooled. Cooled air 1
c is supplied to a gas turbine (not shown).

The control of the flow rate of the first heat medium 1b given to the LNG 1a in the vaporizer 1 is performed by the recycle path L2.
This is performed by adjusting the amount of the first heat medium 1b that recirculates and moves through. That is, when the temperature of the first heat medium 1b immediately before the vaporizer 1 is too high, the temperature controller 71 detects the temperature and the flow controller 7
A signal for increasing the valve opening degree is transmitted to the first control valve 51 via 2 and the valve open degree of the first control valve 51 increases so that the flow rate supplied to the LNG 1a becomes a predetermined value.

Therefore, a large amount of the cooled first heat medium 1b on the downstream side of the vaporizer 1 is supplied to the first heat medium 1b on the upstream side of the vaporizer 1 whose temperature is too high, and is suitable for the vaporizer 1. The first heat medium 1b having the temperature is supplied.

On the contrary, when the temperature of the first heat medium 1b is lower than the preset value, the valve opening degree of the first control valve 51 is narrowed and the cooled first heat medium 1b is upstream of the vaporizer 1. Since the amount of recycling to the side decreases, the temperature of the first heat medium 1b on the upstream side of the vaporizer 1 recovers to the set temperature.

In addition to the above, in the present embodiment, the bypass path L4 is provided from the downstream side of the second heat exchanger 42 in the drawing path L3 to the first circulation path L1 downstream of the first heat exchanger 41. Since the valve 52 is attached to the bypass path L4, the temperature of the first heat medium 1b can be adjusted also by opening / closing the valve 52.

As described in detail above, the present invention is intended for a steam power generation mechanism or a combined power generation mechanism, and the vaporization of LNG1a used as a fuel in them is not performed by heat exchange with seawater as in the conventional case. Instead, it is carried out by heat exchange with the first heat medium 1b made of, for example, industrial water that is circulatingly moving in the vaporization heat source system, and The heat supply is obtained from the used steam 1d generated in the steam power generation mechanism, and by doing so, environmental damage due to cold drainage after heat exchange, which has been a problem in the past, can be effectively performed. In addition to being restrained, the problem of clogging due to the propagation of marine organisms in various pipe tower layers is resolved, and further, corrosion of equipment by seawater is effectively restrained, which is convenient.

(Application) An application example of the present invention on a real scale will be described below. LNG1 supplied to vaporizer 1
The amount of “a” is set to about 30 t / h as a match for the amount of power generation of about 230,000 KW (for one axis of the turbine of the combined cycle power generation facility). In order to vaporize this amount of LNG1a, the vaporizer 1
Is supplied with industrial water of about 10 ° C. at a flow rate of about 1200 t / h, and the first heat medium 1b is set to be cooled to about 5 ° C. in the pit 2 below the vaporizer 1.

From the pit 2, about 1200 t / h
The first heat medium 1b is pumped out and about 850 t /
The h is supplied to the recycle path L2 for recirculation and used, and the remaining about 350 t / h is sent to the first circulation path L1.

Approximately 350t flowing through this first circulation path L1
In the three-way valve 3, a part of the first heat medium 1b of / h is supplied to the second heat exchanger 42 via the withdrawal path L3, where it is used to cool the air 1c and then to the rear first circulation path L1. Joined again. By this heat exchange, about 20 to 30 degrees Celsius
Air 1c is cooled to about 16 ° C to 20 ° C,
The first heat medium 1b discharged from the first heat exchanger 41 is about 15 ° C to 22 ° C.
The temperature is raised to ℃. In addition, the branch supply of the first heat medium 1b to the second heat exchanger 42 is performed only in the summer when the atmospheric temperature is high. Further, normally, the valve 52 attached to the bypass path L4 is closed.

The combined first heat medium 1b is
In the first heat exchanger 41, the heat is exchanged with the second heat medium 1f of about 27 ° C. circulating in the second circulation path L5, and about 22 ° C.
And is discharged from the first heat exchanger 41. The second heat medium 1f after the heat exchange is cooled to about 20 ° C.

[0064]

According to the method and apparatus for vaporizing and supplying liquefied natural gas according to claim 1 or 6, the first heat medium used for vaporizing the liquefied natural gas in the vaporizer is the first circulation. Because it is used by circulating in the route,
Unlike the conventional case, the seawater taken in does not return to the sea as cold drainage due to heat exchange and is effectively returned to the sea. Further, there is no obstruction in the pipe due to the propagation of marine organisms in the intake pipe, etc. due to the intake of seawater. Also, since seawater is not used, corrosion inside the pipe is effectively suppressed.

The liquefied natural gas supplied from outside the system receives heat from the heat medium by heat exchange with the first heat medium in the vaporizer and is vaporized into natural gas, which is then supplied to the boiler, turbine or the like. In addition, even if the first heat medium is low in temperature in the winter due to the influence of the outside air temperature, the second heat medium is circulated in the second circulation system to move the first heat exchanger. It is possible to raise the temperature of the first heat medium through the above, and it is possible to eliminate the disadvantage that the liquefied natural gas is not vaporized properly due to the low temperature of the first heat medium.

According to the method and apparatus for vaporizing and supplying liquefied natural gas according to claim 2 or 7, a recycling route is provided between the first circulation route immediately after the vaporizer and the first circulation route immediately before the vaporizer. Since it is provided, by adjusting the flow rate of the first heat medium to be recirculated to this recycling path, when the carburetor is an open rack type, it prevents the water film from running out causing damage to the equipment, When the vaporizer is an intermediate medium type multitubular heat exchanger, it is possible to easily prevent ice accretion in the thin tubes.

According to the method or apparatus for vaporizing and supplying liquefied natural gas according to claim 3 or 8, the second heat exchanger attached to this path is provided by supplying the first heat medium to the drawing path. In the above, since the heat of the first heat medium cooled by the heat of the vaporizer and the air are cooled, the supply amount of air to the combustion gas turbine is increased and the output of the turbine is increased. You can

According to the method and apparatus for vaporizing and supplying liquefied natural gas according to claim 4 or 9, the liquefied natural gas for vaporizing the liquefied natural gas at the time of startup is provided in the first circulation path on the upstream side of the vaporizer circulation path. Since a startup boiler that supplies a heat source for vaporization is provided, liquefied natural gas is vaporized by the vaporization heat source supplied from the startup boiler even when the heat balance of the entire system is not yet formed at startup, and is supplied as fuel. It is possible to operate the power plant. When the heat balance of the entire system becomes stable, the operation of the start-up boiler should be stopped.

According to the method and apparatus for vaporizing and supplying liquefied natural gas according to claim 5 or 10, since an open rack type vaporizer or an intermediate medium type multi-tube heat exchanger is used as the vaporizer, it is opened. In the case of the open rack type vaporizer of the type, since the first heat medium receives the cold heat from the liquefied natural gas and is frozen, only an ice accretion layer is formed on the outer surface of the vaporizer, and there is no hindrance to the operation. Freezing does not damage the equipment. Further, in the case of the intermediate medium type multi-tube heat exchanger, the heat transfer efficiency is excellent, and the liquefied natural gas can be vaporized more effectively.

[Brief description of drawings]

FIG. 1 is a system diagram showing an example of a liquefied natural gas vaporizer according to the present invention.

FIG. 2 is a perspective view showing an example of an open rack vaporizer.

FIG. 3 is a partially cutaway perspective view showing an example of a heat transfer tube.

[Explanation of symbols]

 1 Vaporizer 1a LNG 1b First heat medium 1c Air (gas turbine intake) 1d Steam 1f Second heat medium 1e Cooling water 1g Steam 11 Lower header 12 Heat transfer pipe 13 Upper header 2 Pit 3 Three-way valve 31 Short-circuit circulation pump 32, 33 Circulation pump 41 First heat exchanger 42 Second heat exchanger 51 First control valve 52 Valve 53 Second control valve 61 Boiler 62 Steam turbine 63 Condenser 71,74 Temperature controller 72 Flow controller 73 Temperature automatic controller 8 Startup boiler L1 First circulation route L2 Recycling route L3 Withdrawal route L4 Bypass route L5 Second circulation route L6 Third circulation route

Claims (10)

[Claims] 1. A steam power generation facility equipped with a steam turbine mechanism for driving a turbine with steam obtained from a boiler, or a turbine driven by combustion gas obtained by burning the steam power generation facility and liquefied natural gas. A method for vaporizing and supplying liquefied natural gas that does not use seawater to vaporize liquefied natural gas that is supplied as fuel to a combined power generation facility that is equipped with a combustion gas turbine mechanism. The second heat medium for vaporization heat supply is circulated and supplied to the vaporizer that vaporizes into gas through the first circulation path, and the second heat for cooling that returns steam to water is returned to the condenser installed in the steam power generation facility. The medium is circulated and supplied through the second circulation path, and the second heat medium is cooled in the first heat exchanger provided over the first circulation path and the second circulation path to generate the first heat. A method for vaporizing and supplying liquefied natural gas, which comprises heating a medium. 2. A recycle path is provided between the first circulation path immediately after the vaporizer and the first circulation path immediately before the vaporizer, and the flow rate of the first heat medium recirculated to the recycle path is adjusted. 2. The method for vaporizing and supplying liquefied natural gas according to claim 1, wherein the method is configured to control the flow rate of the heat source medium that vaporizes the liquefied natural gas. 3. A withdrawal path that branches from the first circulation path into a first circulation path between the downstream side of the vaporizer and the upstream side of the first heat exchanger, and joins with the first circulation path at the downstream side. And a second heat exchanger is provided in the withdrawal path, and a second heat exchanger is provided in the downstream side of the withdrawal path and the first heat exchanger, and a second heat exchanger is provided in the downstream side of the second heat exchanger. A bypass path is formed to connect between the one circulation path and the second heat exchanger to perform heat exchange between the first heat medium and the air for the combustion gas turbine, and is configured to cool the air. The method for vaporizing and supplying liquefied natural gas according to claim 1 or 2, characterized in that: 4. A start-up boiler for supplying a vaporization heat source for vaporizing liquefied natural gas at start-up is provided in the first circulation path upstream of the vaporizer circulation path. 2. The method for vaporizing and supplying liquefied natural gas according to 2 or 3. 5. The method for vaporizing and supplying liquefied natural gas according to claim 1, 2, 3 or 4, wherein the vaporizer is an open rack type vaporizer or an intermediate medium type multi-tube heat exchanger. 6. A steam power generation facility equipped with a steam turbine mechanism for driving a turbine with steam obtained from a boiler, or a turbine driven by combustion gas obtained by burning the steam power generation facility and liquefied natural gas. A vaporization supply device for liquefied natural gas applied to a combined power generation facility that is provided with a combustion gas turbine mechanism, wherein the steam turbine mechanism is provided with a condenser for returning steam after use to water, A carburetor for vaporizing the liquefied natural gas into a natural gas for fuel by heat exchange between the liquefied natural gas supplied from the outside and the first heat medium circulating in the first circulation path formed in the system is provided. , A first heat exchanger is provided in the first circulation path, a second circulation path for circulating a second heat medium is formed between the first heat exchanger and the condenser, and the second heat exchanger is formed. Over the medium Vaporization supply of liquefied natural gas, characterized in that heat is exchanged between the steam supplied to the condenser and the first heat medium supplied to the second heat exchanger. apparatus. 7. A recycle path is provided between the first circulation path immediately after the vaporizer and the first circulation path immediately before the vaporizer, and the flow rate of the first heat medium recirculated to the recycle path is adjusted. The apparatus for vaporizing and supplying liquefied natural gas according to claim 6, which is configured to control the flow rate of the heat source medium that vaporizes the liquefied natural gas. 8. A first circulation path between the downstream side of the vaporizer and the upstream side of the first heat exchanger, and a withdrawal path branched from the first circulation path and joined to the first circulation path on the downstream side. And a second heat exchanger is provided in the withdrawal path, and a second heat exchanger is provided in the downstream side of the withdrawal path and the first heat exchanger, and a second heat exchanger is provided in the downstream side of the second heat exchanger. A bypass path is formed to connect between the one circulation path and the second heat exchanger to perform heat exchange between the first heat medium and the air for the combustion gas turbine, and is configured to cool the air. The liquefied natural gas vaporization supply device according to claim 6 or 7. 9. A start-up boiler for supplying a vaporization heat source for vaporizing liquefied natural gas at start-up is provided in the first circulation path upstream of the vaporizer circulation path. The vaporized supply device for liquefied natural gas according to item 7 or 8. 10. The vaporization supply device for liquefied natural gas according to claim 6, 7, 8 or 9, wherein the vaporizer is an open rack type vaporizer or an intermediate medium type multi-tube heat exchanger.