JP2505694B2 - LNG-fired combined cycle power generation facility - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to LNG (liquefied natural gas) -fired combined cycle power generation equipment, and more particularly to an LNG vaporization system for vaporizing LNG by an LNG vaporizer and supplying it to a power plant as fuel. The present invention relates to a heat source of an LNG carburetor in a gas turbine intake cooling water system in which gas turbine intake cooling water that cools a gas turbine intake air circulates between a gas turbine intake cooling device and an LNG carburetor.

[0002]

2. Description of the Related Art FIG. 3 shows a conventional LNG vaporization system in an LNG-fired combined cycle power generation facility. FIG.
In, the LNG discharged from the LNG tank 1 is pressurized by the LNG pressurizing pump 2 and supplied to the LNG vaporizer 3, where it is heated and vaporized by the seawater supplied from the seawater pump 4 to become NG (natural gas). After that, it is supplied to the gas turbine combustor as fuel for the power plant 5, for example.

Next, FIG. 4 shows a conventional gas turbine intake cooling water system in an LNG-fired combined cycle power generation facility. In FIG. 4, the gas turbine intake cooling water, which has been cooled in the LNG vaporizer 11 by using the cold heat of LNG and whose temperature has dropped, is a gas turbine intake cooling water circulation pump 12
The gas turbine intake air that has been pressurized by the gas turbine intake air cooler 13 and flows into the axial air compressor 15 of the gas turbine power generator 14 is cooled and raised in temperature by the LNG vaporizer 11
It is a circulation path 16 that returns to the.

The LNG is vaporized by the LNG vaporizer 11 to become NG (natural gas), which is supplied to the gas turbine combustor 17 and burned, and the combustion gas is sent to the gas turbine 18 for power generation. The machine 19 is driven.

As described above, the method of cooling the gas turbine intake air with LNG cold heat is more efficient than the LNG direct use method in which the LNG heat transfer tube is installed in the gas turbine intake air cooler 13.
It has the following features. (1) Since the surface temperature of the heat transfer surface can be maintained at 0 ° C. or higher, there is no frosting or icing phenomenon on the heat transfer surface, and it is not necessary to take measures to remove it. (2) Since there is no concern that LNG or NG will be mixed into the intake of the gas turbine, there is no concern about explosive combustion.

[0006]

By the way, the conventional LNG-fired combined cycle power generation facility described above has the following problems.

First, the conventional LNG vaporization system shown in FIG. 3 has the following problems. (1) Since a large amount of seawater is required as a heat source for the LNG vaporizer 3, a large-capacity seawater pump 4 and a seawater supply facility such as a water intake facility are required, and the configuration of the LNG vaporization facility is very complicated. Become. (2) Problems such as adhesion of marine organisms and corrosion of materials are likely to occur in the water contact portion of the seawater supply facility, which causes the maintenance work of the LNG vaporization facility to be complicated and prolonged. (3) The seawater that has left the LNG vaporizer 3 is released to the ocean, but because it is at a low temperature, it will have some effect on the ecosystem, which is one constraint in the location of the LNG vaporizer.

Next, the conventional gas turbine intake cooling water system shown in FIG. 4 has the following problems. (1) When the amount of heat exchange in the gas turbine intake air cooling unit decreases as the atmospheric temperature or the relative humidity decreases, the outlet cooling water temperature of the gas turbine intake air cooler 13 decreases. As a result, the vaporization capacity of the LNG vaporizer 11 is reduced, and stable air supply to the air compressor 15 of the gas turbine power generator 14 cannot be performed. (2) When it is not necessary to cool the gas turbine intake air, such as in winter, the LNG vaporizer 11 does not have a heating source. Therefore, seawater or the like is used as a heat source separately from the gas turbine intake air cooling LNG vaporizer 11. It becomes necessary to install the LNG vaporizer.

The present invention has been made to solve the above-mentioned problems of the prior art. A first object of the present invention is to replace the seawater in the LNG-fired combined cycle power generation facility with one of the cooling water inside the power plant. It is to provide an LNG vaporization system capable of vaporizing LNG by utilizing a part.

A second object of the present invention is to select a part of the internal cooling water of a power plant in the LNG-fired combined cycle power generation facility to vaporize the LNG for cooling the gas turbine intake cooling water. It is an object of the present invention to provide a gas turbine intake cooling water system in which LNG can be vaporized by utilizing the same.

[0011]

In order to achieve the above first object, the present invention provides an LN equipped with an LNG vaporization system which vaporizes LNG by an LNG vaporizer and supplies it as fuel to a power plant.
Internal heat at a G-fired combined cycle power plant
On-site cooling water system of a power plant that is connected to a source and constitutes a circulation system
In addition, a circulation system having an LNG vaporizer is connected in parallel .

Further, the order to achieve the second object, the present invention is between gas turbine intake air cooler and LNG vaporizers
In a gas turbine intake air cooling water system which constitutes the circulation system, where
The internal cooling water system of a power plant, which is connected to an internal heat source and constitutes a circulation system, is connected by a communication means having a flow rate adjusting means .

[0013]

According to the present invention, in the LNG vaporization system of the LNG-fired combined cycle power generation facility, a part of the cooling water in the power plant is guided to the LNG vaporizer to vaporize the LNG.
Since it is possible to use the heat of the in- house heat source for LNG vaporization
Come, and therefore it is that the use of sea water to omit the sea water supply equipment becomes unnecessary. Moreover, it is cooled by the LNG vaporizer
The internal cooling water can be reused for cooling the internal heat source.

Further, according to the present invention, in the gas turbine intake cooling water system of the LNG-fired combined cycle power generation facility, a part of the cooling water in the power plant is transferred to the LNG vaporizer.
LNG can be vaporized by guiding, so that when the atmospheric temperature or relative humidity is lowered or the load is reduced and the heat exchange amount of the gas turbine intake cooling unit is reduced, or when the gas turbine intake cooling is performed in winter, etc. LNG even when not needed
The lack of heat in the vaporizer can be replenished from the in-house cooling water system, so the LNG vaporizer can always be operated only with cooling water, and there is no need to install a spare LNG vaporizer using seawater as a heat source. . That is, in other words, gas
Turbine intake cooling water system circulation system and power plant cooling water
When one system does not have enough heat with the circulatory system of the system
Or, if there is excess, exchange (circulate) the required amount of water.
Can rely on external heat or cooling sources.
It can be adjusted easily.

[0015]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 shows a first embodiment of the present invention. This embodiment is an example in which the present invention is applied to an LNG vaporization system of an LNG-fired combined cycle power generation facility, the same parts as those shown in FIG. 3 are designated by the same reference numerals, and duplicated description will be omitted. To do.

The internal cooling water system (equipment cooling water system) of the power plant in the LNG-fired combined cycle power generation facility comprises a power plant including an air cooling system of a gas turbine and a lubricating oil system of a turbine bearing. The heat is continuously supplied from many devices, and it is possible to supply all of the heat required to vaporize LNG consumed by the LNG-fired combined cycle power generation facility from the on-site cooling water system. Focusing on that, the present invention is a heat source in a plant.
Is connected to the internal cooling water system of the power plant
By connecting the circulation systems with LNG vaporizers in parallel
Therefore, as the heat source of the LNG vaporizer, a part of the in-house cooling water is used instead of the conventionally used seawater.

That is, in FIG. 1, the in-house cooling water that cools a large number of in-house cooling water system heat loads 21 is cooled by the in-house cooling water cooler 22 and supplied to each in-house cooling water system heat load 21, and then the in-house cooling water system heat loads 21. The cooling water pump 23 serves as a circulation path 24 that returns to the on-site cooling water cooler 22. Therefore, in the present invention, a part of the in-house cooling water flowing into the in-house cooling water cooler 22 is guided to the LNG vaporizer 3 through the pipe line 25 to vaporize the LNG. The in-house cooling water that has exchanged heat with the LNG in the LNG vaporizer 3 flows into the in-house cooling water that exits the in-house cooling water cooler 22 in the pipeline 2
Mix through 6.

In this case, the required heat quantity of the LNG vaporizer 3 is L
Although it increases with the output of the NG-fired combined cycle power generation facility, the calorific value of the in-house cooling water system also increases, so part of the in-house cooling water flowing into the in-house cooling water cooler 22 is supplied to the LNG vaporizer 3. By always doing LN
The required amount of heat of the G vaporizer can be stably supplied.

When the distance between the LNG vaporizing equipment and the power plant is large, the internal cooling water booster pump 27 is installed in the middle of the internal cooling water supply pipe 25, and the internal cooling water pump 23 It is advisable to make up for the lack of total head.

In addition, when the initial water temperature of the cooling water system is low and the cooling water temperature at the inlet of the LNG carburetor needs to be rapidly raised, such as at the time of start-up after long-term plant shutdown in winter, or transient LNG vaporization. When the required heat quantity of the device cannot be covered by the heat value of the in-house cooling water system, a cooling water auxiliary heater 28 may be installed at the inlet of the LNG vaporizer 3 to replenish the heat quantity.

Next, FIG. 2 shows a second embodiment of the present invention.
This examples are those applied to the gas turbine intake air cooling water system of the combined cycle power plant burning LNG to the present invention, between the gas turbine intake air cooler and LNG vaporizers
Gas turbine intake cooling water system that constitutes a circulation system with
Cooling water inside a power plant that is connected to an internal heat source and forms a circulation system
The system is connected with the communication means equipped with the flow rate adjusting means.
It is like that.

That is, in FIG. 2, a large number of on-site cooling water system heat loads 31 such as the air cooling system of the turbine of the power plant.
The in-house cooling water for cooling is cooled by the in-house cooling water cooler 32 and supplied to each in-house cooling water system heat load 31, and then returned to the in-house cooling water cooler 32 by the in-house cooling water pump 33. Has become. Therefore, in the present invention, a part of the internal cooling water flowing into the internal cooling water cooler 32 can be selectively used as a heat source for vaporizing LNG in the LNG vaporizer 11.

More specifically , according to the embodiment shown in FIG. 2, a pipe 35 for taking out a part of the in-house cooling water flowing into the in-house cooling water cooler 32 is branched from the in-house cooling water circulation system passage 34. The gas turbine intake cooling water circulation system passage 16 is connected to the inlet side portion of the gas turbine intake cooling water circulation pump 12. A temperature control valve 36 is provided in the middle of the pipe 35, and the temperature control valve 36 controls the intake cooling water circulation pump 12 of the gas turbine intake cooling water circulation system passage 16.
It is configured to be controlled by a temperature controller 37 provided at the outlet side portion.

Therefore, when the amount of heat exchange in the gas turbine intake air cooler 13 decreases with a decrease in atmospheric temperature or relative humidity, the temperature control valve 3 is passed through the temperature controller 37.
6, a part of the in-house cooling water flowing out of the in-house cooling water pump 33 and flowing into the in-house cooling water cooler 32 is passed through the pipe 35 to the gas turbine intake cooling water flowing into the gas turbine intake cooling water circulation pump 12. Inject, which results in LNG
The heat quantity that is insufficient in the vaporizer 11 is supplied from the in-house cooling water system.

The injection amount of the on-site cooling water to the gas turbine intake cooling water is adjusted by a flow rate control valve 36 which operates according to the output signal of the gas turbine intake cooling water temperature controller 37 supplied to the LNG vaporizer 11. Then, the temperature of the gas turbine intake cooling water is controlled to be a constant value.

The amount of gas turbine intake cooling water supplied to the LNG vaporizer 11 is controlled by a temperature controller on the outlet side of the LNG vaporizer 11 so that the cooling water outlet temperature at the outlet of the LNG vaporizer 11 becomes constant. It is controlled by a temperature control valve 39 on the inlet side of the LNG vaporizer 11, which is operated by the output signal of 38.

Further, the same amount of the intake cooling water as the indoor cooling water injected into the gas turbine intake cooling water is branched from the part of the gas turbine intake cooling water circulation system 16 on the outlet side of the gas turbine intake cooler 13 for internal cooling. The water is circulated to the in-house cooling water circulation system passage 34 through the pipe 40 connected to the outlet side portion of the in-house cooling water cooler 32 of the water circulation system passage 34. In addition,
Reference numerals 42 and 43 are check valves.

When the gas turbine intake air cooler 13 is not used, such as in winter, the intake air cooling water is allowed to flow through the bypass pipe 41 of the intake air cooler 13 and the temperature control valve 36 is fully opened. The heating amount required by the LNG vaporizer 11 is supplied from the cooling water system in the plant.

Further, the LNG vaporizer 1 has a low initial water temperature in the cooling water system, such as when the plant is started after a long shutdown in winter.
When it is necessary to quickly raise the inlet cooling water temperature of No. 1 or when the required heat quantity of the LNG vaporizer 11 cannot be covered by the calorific value of the in-house cooling water system transiently, the LNG vaporizer inlet is cooled. A water auxiliary heater (not shown) may be provided to supply heat.

[0031]

As described above, according to the present invention, L
In an LNG-fired combined cycle power generation facility equipped with an LNG vaporization system that vaporizes NG with an LNG vaporizer and supplies it as fuel to a power plant, an internal heat source is connected to a circulating system.
An LNG vaporizer is installed in the cooling water system of the constituent power plants.
By connecting the circulating systems in parallel, thereby guiding a part of the in-house cooling water from the in-house cooling water system of the power plant to the LNG vaporizer so that it can be used as a heat source of the LNG vaporizer. The effect like is obtained.

(1) Since the seawater supply equipment attached to the LNG vaporization equipment can be omitted, the LNG vaporization equipment can be greatly simplified. (2) Re-use the low temperature internal cooling water cooled by the LNG vaporizer.
And cooling the internal heat source and joining the internal cooling water cooler with the outgoing internal cooling water, the required heat exchange amount of the internal cooling water cooler can be reduced. The capacity of the vessel and the seawater supply equipment attached to it can be reduced. (3) Since the power required for circulating the in-house cooling water system can be used as a part of the power required for circulating the cooling water, L
The operating cost of the NG vaporization facility can be reduced. (4) Since seawater is not handled, maintenance of equipment is easy,
The maintenance cost can be reduced and the maintenance period can be shortened. (5) Reducing the amount of heat exhausted from the power plant by reducing the amount of heat treated by the on-site cooling water cooler, and eliminating the cold exhaust heat from the LNG vaporizer reduces the impact on the marine ecosystem. can do.

Further, according to the present invention, a gas turbine intake air cooling water system which constitutes the circulation system between the gas turbine intake air cooler and LNG vaporizers, the plant heat source is connected to the circulatory system
The cooling water system of the constituent power plants shall be connected to the flow control means.
It can be connected by the provided communication means, whereby a part of the in-house cooling water from the in-house cooling water system of the power plant can be selectively injected into the gas turbine intake cooling water system and used as a heat source for the LNG vaporizer. By doing so, the following effects can be obtained.

According to the present invention, the gas turbine intake cooling water system is backed up by the on-site cooling water system, and even if the heat exchange amount of the gas turbine intake cooling device is reduced, the gas turbine intake cooling water is always used. Because the LNG vaporizer can continue to operate, a backup LN that uses seawater as a heat source
There is no need to install a G vaporizer . That is, in other words
Then, the circulation system of the gas turbine intake cooling water system and the power plant
Between the circulation system of the on-site cooling water system and one system,
If not, or if there is surplus, replace the necessary amount of water (circulation).
It can be used as an external heat source or cooling source.
It can be adjusted independently.

[Brief description of drawings]

FIG. 1 is an LNG vaporization system diagram showing an example of an LNG-fired combined cycle power generation facility according to the present invention.

FIG. 2 is a gas turbine intake cooling water system diagram showing another example of the LNG-fired combined cycle power generation facility according to the present invention.

FIG. 3 is a LNG vaporization system diagram showing an example of a conventional LNG-fired combined cycle power generation facility.

FIG. 4 is a gas turbine intake cooling water system diagram showing another example of a conventional LNG-fired combined cycle power generation facility.

[Explanation of symbols]

 1 LNG tank 2 LNG pressurizing pump 3 LNG vaporizer 5 power plant 11 LNG vaporizer 12 gas turbine intake cooling water circulation pump 13 gas turbine intake cooler 14 gas turbine power generator 15 gas turbine compressor 16 gas turbine intake cooling water circulation system passage 17 Gas Turbine Combustor 18 Gas Turbine 19 Generator 21 Internal Cooling Water System Heat Load 22 Internal Cooling Water Cooler 23 Internal Cooling Water Pump 24 Internal Cooling Water Circulation System 25 Internal Cooling Water Supply Pipeline 26 Internal Cooling Water Return Pipeline 27 Internal cooling water booster pump 28 Cooling water auxiliary heater 31 Internal cooling water system heat load 32 Internal cooling water cooler 33 Internal cooling water pump 34 Internal cooling water circulation system 35 Internal cooling water supply pipe 36 Temperature control valve 37 Temperature controller 38 Temperature Controller 39 Temperature Control Valve 40 Cooling Water Return Pipeline 41 By Scan line 42 check valve 43 check valve

Front page continuation (72) Inventor Haruki Yajima 1-1-1, Niihama, Arai-cho, Takasago-shi, Hyogo Mitsubishi Heavy Industries, Ltd. Takasago Plant (56) Reference JP-A-56-47625 (JP, A)

Claims (2)

(57) [Claims] 1. A LNG-fired combined-cycle power plant with a LNG vaporization system for supplying LNG as a fuel to vaporize to power plants with LNG vaporizers, plant heat source contact
L is connected to the cooling water system in the power station of the power plant
A LNG-fired combined cycle power generation facility characterized in that a circulation system having an NG vaporizer is connected in parallel . 2. A gas turbine intake air cooler and LNG vaporizers
Gas turbine intake cooling water system that forms a circulation system between
And the internal cooling water system of the power plant, which is connected to the internal heat source and constitutes a circulation system, by a communication means equipped with a flow rate control means.
LNG-fired combined cycle power generation facility characterized by continuation .