JP2008232047A - Cooling system for gas turbine combustion air - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling system for gas turbine combustion air capable of reducing facility cost and operation cost by effectively utilizing heat. <P>SOLUTION: This system includes at least two carburetors vaporizing low temperature liquefied gas for fuel of a gas turbine, an air cooler 21 cooling air for combustion of the gas turbine, a water circulation line capable of sending water which is medium vaporizing low temperature liquefied gas to a first carburetor 11 and sending cooled water to the air cooler 21 as coolant, a water circulation device 31 provided with a water circulation pump 25, a heat exchanger 41 heating water provided in a middle of the water circulation line and outlet side of the air cooler 21, and a seawater line 51 capable of supplying hot seawater for heating water to the heat exchanger 41 and sending hot seawater of which temperature is dropped after heat exchange with water in the heat exchanger 41 to a second carburetor 12 as medium vaporizing low temperature liquefied gas. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a cooling system for a combustion air of a gas turbine, and more particularly to a cooling system for a combustion air of a gas turbine that cools the combustion air of a gas turbine by using the cold heat of a low-temperature liquefied gas for fuel of the gas turbine.

  In recent years, many combined power generation facilities using liquefied natural gas have been used. A typical combined power generation using liquefied natural gas is a combustion in which a gas turbine is driven by using liquefied natural gas (hereinafter referred to as LNG), which is a kind of low-temperature liquefied gas, and is discharged from the gas turbine by an exhaust heat recovery boiler. The heat of the exhaust gas is recovered and the steam turbine is driven to generate power. LNG used as a fuel for a gas turbine is obtained by cooling and liquefying natural gas mainly composed of methane (hereinafter referred to as NG), and is stored in an LNG tank in a power plant or the like. Since LNG is stored at a temperature of about −162 ° C., when it is used as a fuel, it is necessary to warm and gasify it as NG. For gasification of LNG, a vaporizer using seawater as a heat medium such as an open rack type vaporizer and a shell and tube type vaporizer is often used.

  By the way, the gas turbine of the combined power generation facility is obtained by an air compressor in which combustion air is connected to the output shaft of the gas turbine. Therefore, when the atmospheric temperature rises, the density of the intake air of the gas turbine decreases, and the air compressor The amount of air sent out decreases. Along with this, it is necessary to reduce the fuel flow rate, and the shaft output of the gas turbine decreases. For this reason, several methods for cooling the intake air of the gas turbine have been proposed. For example, the antifreeze liquid is cooled to about −40 ° C. by the LNG for fuel of the gas turbine and stored in a low temperature regenerator, and the antifreeze in the low temperature regenerator is air-cooled in a time zone when the air temperature is high and the power demand is increased. There has been proposed a cooling system that cools the intake air of the gas turbine by sending it to a cooler and uses NG vaporized by heat exchange with the antifreeze liquid as fuel for the gas turbine (see, for example, Patent Document 1).

In the method described in Patent Document 1, it is pointed out that icing may occur on the surface of the air cooler and the air cooling performance may be lowered because the combustion air is cooled with an antifreeze liquid at −40 ° C. Some point out that the equipment costs are high. In order to solve these problems, a new cooling system for gas turbine combustion air has also been proposed (see, for example, Patent Document 2). The inventors have also invented a new gas turbine combustion air cooling system and have already filed a patent application (see, for example, Patent Document 3).
Japanese Patent Laid-Open No. 9-209718 JP 2000-18049 A JP 2000-145476 A

  In the technique described in Patent Document 2, when cooling of combustion air is necessary, the heat medium of the vaporizer is switched from seawater to water such as industrial water, and the water cooled in the vaporizer is air-cooled through a circulation line. The intake air of the gas turbine is cooled by sending it to the vessel. Further, the technique described in Patent Document 3 made by the present inventors was cooled in the vaporizer by continuously operating the circulation line of seawater and cooling water when the combustion air needs to be cooled. Seawater is used for cooling the cooling water, and the intake air of the gas turbine is cooled with this cooling water.

  According to the methods described in Patent Document 2 and Patent Document 3, since the cooling medium sent to the air cooler is water having a temperature of 0 ° C. or higher, there is no fear of icing on the air cooler surface. Furthermore, it can be said that the piping material is a useful method because it is not necessary to use an expensive low-temperature material. However, the techniques described in Patent Document 2 and Patent Document 3 are not completely complete, and furthermore, a gas turbine combustion air cooling system that effectively uses heat, or the running cost is low or the operation is low. Development of an easy cooling system for gas turbine combustion air is expected.

  An object of the present invention is to provide a gas turbine combustion air cooling system that can effectively use heat and reduce facility costs and operation costs. Another object of the present invention is to provide a gas turbine combustion air cooling system that can be easily applied to existing gas turbine combustion equipment.

The present invention comprises at least two vaporizers for vaporizing a low temperature liquefied gas for fuel of a gas turbine;
An air cooler for cooling the combustion air of the gas turbine;
A water circulation line including a water circulation line capable of sending water, which is a medium for vaporizing the low-temperature liquefied gas, to the first vaporizer, and sending the cooled water as a refrigerant to the air cooler, and a water circulation pump;
A heat exchanger for heating water disposed in the middle of the water circulation line and on the outlet side of the air cooler;
Warm seawater that heats water is supplied to the heat exchanger, and the warm seawater that is heat-exchanged with the water in the heat exchanger to lower the temperature can be sent to the second vaporizer as a medium for vaporizing the low-temperature liquefied gas Seawater line,
A gas turbine combustion air cooling system comprising:

The present invention further includes a heat exchanger bypass line disposed in the water circulation line that bypasses the heat exchanger;
A vaporizer water supply temperature control valve disposed in the water circulation line capable of adjusting a flow rate of water in the heat exchanger and / or the heat exchanger bypass line;
A vaporizer water supply temperature control device that detects a temperature of water supplied to the first vaporizer and outputs a control signal to the vaporizer water supply temperature control valve;
The gas turbine combustion air cooling system according to claim 1, comprising:

The present invention further includes an air cooler bypass line disposed in the water circulation line that bypasses the air cooler,
An air cooler temperature control valve disposed in the water circulation line capable of adjusting a flow rate of water in the air cooler and / or the air cooler bypass line;
The temperature of at least one of the outlet cooling temperature of the combustion air of the gas turbine cooled by the air cooler, the inlet air temperature of the air cooler, or the atmospheric temperature is detected, and the temperature control valve of the air cooler is detected. An air cooler temperature control device for outputting a control signal;
The gas turbine combustion air cooling system according to claim 1, wherein the gas turbine combustion air cooling system is included.

  The gas according to any one of claims 1 to 3, wherein in the present invention, the warm seawater is seawater containing warm seawater after passing through the condenser of a condenser for cooling steam. A cooling system for turbine combustion air.

  A gas turbine combustion air cooling system according to the present invention includes at least two vaporizers that vaporize a low-temperature liquefied gas for fuel of a gas turbine, and an air cooler that cools combustion air of the gas turbine. Water, which is a medium for vaporizing the liquefied gas, is sent to the first vaporizer, and the cooled water is sent to the air cooler as a refrigerant, so the cooling air of the low-temperature liquefied gas is used to convert the combustion air of the gas turbine. It becomes possible to cool, and effective use of heat can be aimed at. In addition, since it has a heat exchanger that heats the water on the outlet side of the air cooler in the middle of the water circulation line that circulates between the first vaporizer and the air cooler, the load on the air cooler is reduced. Even if the temperature of the water at the outlet of the air cooler decreases, the water can be heated and fed to the first vaporizer, and the first vaporizer can be operated stably.

  Furthermore, the heating medium of the heat exchanger that heats the water on the outlet side of the air cooler is warm seawater, and this warm seawater is used as a medium for vaporizing the low-temperature liquefied gas of the second vaporizer, so that heat is effective. Can be used. By adopting such a configuration, the heat medium lines of the two vaporizers are substantially connected in series, and the two vaporizers are operated with one vaporizer seawater pump. Can do. In the conventional vaporizer vaporization system, the number of vaporizer seawater pumps corresponding to the number of each vaporizer is required. However, in the present invention, two vaporizer seawater pumps are used as described above. Therefore, the number of vaporizer seawater pumps can be reduced, and the equipment cost can be reduced. Moreover, the operating cost of the vaporizer seawater pump can be suppressed. Furthermore, the gas turbine combustion air cooling system of the present invention has a simple configuration and can be easily applied to existing gas turbine combustion equipment.

  The present invention further includes a heat exchanger bypass line disposed in a water circulation line that bypasses the heat exchanger, and a water circulation line that can adjust the flow rate of water in the heat exchanger and / or the heat exchanger bypass line. And a vaporizer water temperature control device that detects the temperature of the water fed to the first vaporizer and outputs a control signal to the vaporizer water temperature control valve. The temperature of the water sent to the vaporizer can be adjusted to a predetermined temperature. Thereby, the first vaporizer can be stably operated and the cooling capacity of the air cooler can be increased.

  The present invention further includes an air cooler bypass line disposed in a water circulation line that bypasses the air cooler, and a water circulation line that can adjust the flow rate of water in the air cooler and / or the air cooler bypass line. And detecting the temperature of at least one of the outlet air cooling temperature of the combustion air of the gas turbine cooled by the air cooler, the inlet air temperature of the air cooler, or the atmospheric temperature, An air cooler temperature control device that outputs a control signal to the cooler temperature control valve, so that the flow rate of water flowing through the air cooler and the air cooler bypass line can be adjusted even if the atmospheric temperature changes Thus, the temperature of the air cooled by the air cooler can be adjusted, and the output of the gas turbine can be increased.

  Further, according to the present invention, the warm seawater is seawater containing the warm seawater after passing through the condenser of the condenser that cools the steam, so that the energy of the warm seawater after passing through the condenser is effectively used. can do. By applying the present invention, it is possible to recover heat that has been wasted in the past as it is and use it effectively. Further, the seawater temperature to be discharged is brought close to the water seawater temperature, which is environmentally preferable.

  FIG. 1 is a flowchart showing a schematic configuration of a gas turbine combustion air cooling system 1 according to a first embodiment of the present invention. The gas turbine combustion air cooling system 1 is a system that cools gas turbine combustion air using the cold heat of the gas turbine fuel LNG, and includes a first vaporizer 11 and a second vaporizer that vaporize LNG. Water circulation for circulating water between the vaporizer 12, the air cooler 21 for cooling the combustion air of the gas turbine using the water vaporized LNG as the cooling medium, and the first vaporizer 11 and the air cooler 21 A heat exchanger 41 that heats water circulating between the device 31, the first vaporizer 11 and the air cooler 21, and a seawater line 51 that supplies warm seawater to the heat exchanger 41 and the second vaporizer 12. Mainly composed.

  In the gas turbine combustion air cooling system 1 shown in the present embodiment, as will be described later, a medium (heat medium) line for vaporizing LNG of two vaporizers is connected in series, and the first vaporization is performed. It is characterized in that the heat medium whose temperature is lowered by the vessel 11 is used as the heat medium of the second vaporizer 12. Therefore, the gas turbine combustion air cooling system 1 of the present invention requires at least two vaporizers as shown in the first embodiment. The first vaporizer 11 uses water such as industrial water as a heat medium for vaporizing LNG, and the second vaporizer 12 uses seawater as a heat medium for vaporizing LNG.

  The first vaporizer 11 and the second vaporizer 12 are both open rack vaporizers (ORV), a panel (not shown) made up of a large number of finned heat transfer tubes, and a heat medium that vaporizes LNG on the surface of the panel. NG troughs 13 and 15 for supplying LNG, LNG is caused to flow in the panel, and a heat medium is caused to flow down the surface of the panel to vaporize LNG. Below the first vaporizer 11 and the second vaporizer 12, lower buses 14 and 16 for collecting the heat medium flowing down the panel are provided. The lower bus 14 has a pipe line 33 that guides water collected at the bottom to a water tank 32 that constitutes a part of the water circulation device 31. On the other hand, a pipe line 52 for returning the recovered seawater to the sea is disposed at the bottom of the lower bus 16.

  The air cooler 21 cools the combustion air of the gas turbine using water whose LNG has been vaporized and reduced in temperature by the first vaporizer 11 as a cooling medium, and receives the cooling medium via the water circulation device 31. The water circulation device 31 is a device that circulates water between the first vaporizer 11 and the air cooler 21, and a storage tank 32 that stores circulating water (cooling water) such as industrial water that cools the air cooler 21. A water circulation pump 25 that sends the circulating water in the storage tank to the air cooler 21 and a pipe that sends the circulating water sent from the water circulation pump 25 to the air cooler 21 are configured. A pipe 34 is connected to the discharge part of the water circulation pump 25, and one end of the pipe 34 is connected to the three-way flow control valve 35. The three-way flow rate control valve 35 is connected to a pipe line 36 that sends circulating water to the air cooler 21 and an air cooler bypass pipe line 37 that bypasses the air cooler 21 and functions as an air cooler temperature control valve.

  The air cooler 21 is connected to a conduit 38 for returning the circulating water sent through the conduit 36 to the storage tank 31, and the air cooler bypass conduit 37 is connected to the conduit 38. Therefore, the air cooler 21 can be bypassed via the pipe line 37, and the circulating water sent out by the water circulation pump 25 can be returned to the storage tank 31. The air cooler 21 includes a temperature detector (not shown) that detects the temperature of the outlet cooling air, and a signal from the temperature detector is input to an air cooler temperature control device (not shown). The air cooler temperature control device includes a temperature setter that can set the temperature of the outlet cooling air of the air cooler 21 and outputs a flow control signal to the three-way flow control valve 35 based on a signal from the temperature detector. As a result, the flow rates of the air cooler 21 and the air cooler bypass pipe 37 can be adjusted to an arbitrary ratio, and the outlet cooling air of the air cooler 21 can be set to a predetermined temperature.

  One end of the pipe line 38 is connected to the three-way flow control valve 39. The three-way flow control valve 39 connects the circulating water returned through the pipe 38 to the pipe 40 that sends the heat to the heat exchanger 41, and the heat exchanger bypass pipe 42 that bypasses the heat exchanger 41. Functions as a control valve. At the outlet of the heat exchanger 41, a pipe line 43 for returning the heated circulating water to the trough 13 is disposed, and the pipe line 43 is connected to the heat exchanger bypass pipe line.

  A temperature detector (not shown) for detecting the circulating water temperature at the trough inlet is mounted on the downstream side of the connecting portion between the heat exchanger bypass pipe 42 and the pipe 43, and the signal of the temperature detector Is input to the vaporizer water supply temperature control device (not shown). The vaporizer water supply temperature control device includes a temperature setter that can set the temperature of the circulating water at the trough inlet of the first vaporizer 11, and sends a flow control signal to the three-way flow control valve 39 based on the signal from the temperature detector. Output. As a result, the flow rates of the heat exchanger 41 and the heat exchanger bypass pipe 42 can be adjusted to an arbitrary ratio, and the circulating water temperature at the trough inlet can be adjusted to a predetermined temperature.

  Since the water circulation device 31 has the above-described configuration, the storage tank 32, the pipe 34, the three-way flow control valve 35, the pipe 36, the air cooler 21, the pipe 38, the three-way flow control valve 39, the pipe 40, and heat exchange. A circulation line is formed by the vessel 41, the pipelines 43 and 42, the trough 13, the first vaporizer 11, the lower bus 14, and the pipeline 33, and circulating water can be circulated by the water circulation pump 25. Even if the air cooler bypass line 37 and / or the heat exchanger bypass line 42 are used, the circulating water can be circulated. The three-way flow rate adjustment valve 35 constituting a part of the water circulation device 31 is for adjusting the amount of circulating water flowing through the air cooler 21 and the air cooler bypass pipe 37, and therefore is replaced with the three-way flow rate adjustment valve 35. The flow control valve may be attached to the pipe line 36 and the air cooler bypass pipe line 37. Similarly, instead of the three-way flow control valve 39, a flow control valve may be attached to the pipe line 40 and the heat exchanger bypass pipe line 42.

  Furthermore, the mounting position of the temperature detector is not limited to the above embodiment. For example, in the air cooler 21, a temperature detector may be installed in the pipe line 36 and the pipe line 38, and the temperature of the circulating water may be detected and controlled to control the outlet cooling temperature of the cooling air. Further, a temperature detector capable of detecting the inlet air temperature of the air cooler 21 or the atmospheric temperature may be installed, and the outlet cooling temperature of the cooling air may be controlled by detecting these temperatures.

  The heat exchanger 41 is a partition wall heat exchanger for heating the cooling water whose temperature has been lowered by the air cooler 21 and uses warm seawater as a heating medium. Here, the warm seawater refers to seawater having a temperature higher than that of normal seawater, and examples include seawater including warm seawater at the outlet of a condenser that has cooled the exhaust steam of the steam turbine and raised the temperature. . The warm seawater is supplied to the heat exchanger 41 through the seawater line 51. The seawater line 51 is a pipe 53 for sending warm seawater sent by the vaporizer seawater pump 27 installed at a water outlet or the like to the heat exchanger 41, and warm seawater whose temperature has been lowered by heat exchange in the heat exchanger 41. The pipe 54 is configured to be sent as a heat medium for the second vaporizer 12. The pipe line 54 is connected to the trough-like trough 15 of the second vaporizer 12, and the warm seawater is guided to a panel (not shown) of the second vaporizer 12. The warm seawater flowing down the panel is collected by the lower bus 16 and returned to the sea through the pipeline 52.

  Further, the pipe line 53 for sending the warm seawater supplied by the vaporizer seawater pump 27 to the heat exchanger 41 has a branch part in the middle of the pipe line, and a seawater bypass pipe line 55 that bypasses the heat exchanger 41 at this branch part. Are linked. The seawater bypass pipeline 55 has a valve 56 in the middle of the pipeline, and one end of the seawater bypass pipeline 55 is connected to the pipeline 54. Since the pipe 54 also has the valve 57 in the middle of the pipe, the heat exchanger 41 can be bypassed, and the warm seawater can be sent to the second vaporizer 12 through the seawater bypass pipe 55.

  Next, the usage method of the cooling system 1 of the gas turbine combustion air which consists of the above structure is shown. When the air temperature is high and the power demand increases, such as in summer, the combustion air of the gas turbine is cooled in the following manner. In order to cool the combustion air of the gas turbine, circulating water as a cooling medium is sent to the air cooler 21. Circulating water is circulated through the water circulation pump 25 using the system of the storage tank 32, the air cooler 21, the heat exchanger bypass conduit 42, the trough 13, the first vaporizer 11, and the lower bus 14.

  The circulating water lowers the temperature by vaporizing the LNG of the first vaporizer 11, and is sent to the air cooler 21 to cool the combustion air having a high temperature. On the other hand, the circulating water itself raises the temperature, and the circulating water whose temperature has risen is led to the first vaporizer 11 as a heat medium for vaporizing the LNG of the first vaporizer 11 while maintaining the temperature. Since the circulating water led to the first vaporizer 11 is heated by the air cooler 21 and has a high temperature, LNG can be stably vaporized without being heated using the heat exchanger 41. Can do. Here, it can be said that a system for cooling the combustion air of the gas turbine using the cold heat of LNG is established.

  Warm seawater is used as a heating medium for vaporizing the LNG of the second vaporizer 12. The vaporizer seawater pump 27 is operated, the valve 56 is opened, and the valve 57 is closed, whereby the second vaporizer 12 is warmed via the pipeline 53, the seawater bypass pipeline 55 bypassing the heat exchanger 41, and the trough 15. Supply seawater. The LNG supplied to the second vaporizer 12 becomes NG with this warm seawater, and the warm seawater that has been vaporized and reduced in temperature is collected by the lower bus 16 and returned to the sea through the pipeline 52.

  Next, a method of using the gas turbine combustion air cooling system 1 when the load on the air cooler 21 is not high in the summer, such as in a time zone other than after noon, will be described. When the load of the air cooler 21 is not high, it is not necessary to send a large amount of circulating water to the air cooler 21 in order to cool the air. On the other hand, when the load of the air cooler 21 is not high, the circulating water temperature on the outlet side of the air cooler 21 is not sufficiently high. Therefore, in order to use it as a medium for vaporizing LNG, this circulating water is used. It is necessary to increase the temperature. Therefore, when the load of the air cooler 21 is not high, the storage tank 32, the air cooler 21 and the air cooler bypass line 37, the heat exchanger 41 and the heat exchanger bypass line 42, the trough 13, the first vaporization The circulating water is circulated through the water circulation pump 25 using the system of the vessel 11 and the lower bus 14.

  The flow rate adjustment of the air cooler 21 and the air cooler bypass pipe 37 is performed by adjusting the temperature of the outlet cooling air of the air cooler 21 (not shown) so that the outlet cooling temperature of the gas turbine combustion air becomes a predetermined temperature. This is done by sending a flow rate control signal to the three-way flow rate control valve 35 using a temperature detector to be detected and an air cooler temperature control device. Similarly, the flow rate of the heat exchanger 41 and the heat exchanger bypass pipe 42 is adjusted so that the circulating water temperature at the trough inlet is not shown so that the circulating water has a predetermined temperature at the trough inlet and vaporization is omitted. This is done by sending a flow rate control signal to the three-way flow rate control valve 39 using a water supply temperature control device. By performing the operation in this manner, even when the load of the air cooler 21 is not high, the combustion air of the gas turbine can be cooled and the LNG can be vaporized in the first vaporizer 11 without any problem. .

  On the other hand, as the heat medium for vaporizing the LNG of the second vaporizer 12, warm seawater is used in which heat is exchanged with circulating water in the heat exchanger 41 to lower the temperature. The warm seawater used for heating the circulating water can be used as a heat medium for vaporizing LNG because the original seawater temperature is high although the temperature is lowered. The warm seawater sent from the vaporizer seawater pump 27 decreases the temperature through the pipe line 53 and the heat exchanger 41, and is sent to the trough 15 of the second vaporizer 12 through the pipe line 54. The warm seawater flowing down from the trough heats a panel (not shown) and then returns to the sea through the lower bus 16 and the pipeline 52.

  When the atmospheric temperature other than summer is relatively low and therefore it is not necessary to cool the combustion air of the gas turbine, the circulating water is stored in the storage tank 32, the water circulation pump 25, the air cooler bypass line 37, and the heat exchanger 41. The trough 13, the vaporizer 11, and the lower bus 14 are circulated. When it is not necessary to cool the combustion air of the gas turbine, it is not necessary to supply the cooling water to the air cooler 21, so the circulating water is circulated through the air cooler bypass pipe 37. Since this circulating water is used as a heat medium for vaporizing LNG of the first vaporizer 11, on the other hand, when circulating water is circulated without passing through the air cooler 21, the circulating water is connected to the pipe 40. To the heat exchanger 41, where it is heated to a predetermined temperature. Thereby, the circulating water whose temperature became high is supplied to the 1st vaporizer 11, and LNG can be vaporized stably.

  On the other hand, as the heat medium for vaporizing the LNG of the second vaporizer 12, warm seawater is used in which heat is exchanged with circulating water in the heat exchanger 41 to lower the temperature. The warm seawater used for heating the circulating water can be used as a heat medium for vaporizing LNG because the original seawater temperature is high although the temperature is lowered. The warm seawater sent from the vaporizer seawater pump 27 decreases the temperature through the pipe line 53 and the heat exchanger 41, and is sent to the trough 15 of the second vaporizer 12 through the pipe line 54. The warm seawater flowing down from the trough heats a panel (not shown) and then returns to the sea through the lower bus 16 and the pipeline 52.

  An example of the temperature at various places when the atmospheric temperature other than summer is relatively low and therefore it is not necessary to cool the combustion air of the gas turbine is as follows. When the seawater temperature at the power plant intake is 9 to 10 ° C., the seawater temperature at the outlet including the warm seawater exiting the condenser is about 17 ° C. If this 17 degreeC warm seawater passes the heat exchanger 41, it will become about 12 degreeC and temperature will fall about 5 degreeC. The warm seawater of about 12 ° C., whose temperature has been reduced by the heat exchanger 41, is sent to the second vaporizer 12, and when LNG is vaporized, it falls to a temperature of 7-8 ° C. and merges with the warm seawater of the discharge channel. Returned to the sea at a temperature of 9-10 ° C.

  FIG. 2 is a flowchart showing a schematic configuration of a gas turbine combustion air cooling system 100 according to a second embodiment of the present invention. The same members as those in the gas turbine combustion air cooling system 1 shown in FIG. It can be seen that the gas turbine combustion air cooling system 100 shown in the second embodiment differs from the gas turbine combustion air cooling system 1 shown in the first embodiment in the shape and structure of the vaporizer.

  The first vaporizer 111 and the second vaporizer 112 shown in the second embodiment are shell and tube type vaporizers. As long as it is a shell and tube type vaporizer, the structure, model, etc. are not particularly limited. The shell-and-tube type vaporizer is a kind of partition wall heat exchanger. For example, LNG is vaporized by supplying heat from the heat medium by supplying LNG to the tube side and supplying a heat medium to the shell side. NG. In the shell and tube type vaporizer, unlike the open rack type vaporizer, the heat medium circulates in the shell. Therefore, as shown in FIG. 2, the lower water bath 14 for collecting the circulating water and the storage tank 32 for storing the circulating water are unnecessary at the circulating water outlet of the shell-and-tube type first vaporizer 111. By connecting the pipe line 33 and the water circulation pump 25, the circulating water can be circulated.

  The gas turbine combustion air cooling system 100 according to the second embodiment has the same basic configuration as the gas turbine combustion air cooling system 1 shown in the first embodiment except for the carburetor. Also, the same method as the method shown in the first embodiment can be adopted. Note that the first vaporizer 111 and the second vaporizer 112 are not necessarily the same type of vaporizer, and therefore it is possible to employ an open rack vaporizer as the second vaporizer 112.

  In the above embodiment, the gas turbine combustion air cooling system having two carburetors is shown, but the present invention can also be applied to power generation equipment having three or more carburetors. In this case, the gas turbine combustion air cooling system shown in the present embodiment is constructed using two carburetors, and the remaining one or more carburetors are vaporized in the same manner as the conventional carburetor vaporization system. What is necessary is just to supply warm seawater or normal seawater as a heat carrier with a container seawater pump.

  As described above, the gas turbine combustion air cooling systems 1 and 100 shown in the first embodiment and the second embodiment are excellent in cooling the gas turbine combustion air by using the cold energy of the fuel LNG of the gas turbine. System. Also, in summer, when the load of the air cooler is not high, as in the time zone other than after noon, and the air temperature outside summer is relatively low, it is not necessary to cool the combustion air of the gas turbine. When the circulating water, which is a heat medium for vaporizing the LNG in the first vaporizers 11 and 111, is heated with warm seawater, the warm seawater that is heat-exchanged with the circulating water to reduce the temperature is further added to the second vaporizer 12 and 112 as LNG vaporization medium. This can be said to be that the heat medium lines of the two vaporizers are connected in series. Thereby, it becomes possible to send a heat medium to two vaporizers with one vaporizer seawater pump.

  Compared with the conventional gas turbine combustion air cooling system in which seawater is sent to one carburetor by one carburetor seawater pump, the gas turbine combustion air cooling system 1 of the present invention, In 100, the installation cost and the operating cost due to the decrease in the number of vaporizer seawater pumps can be reduced. The present invention is a system that is made possible by using high-temperature seawater. In the present invention, however, warm seawater for use in two vaporizers is not produced, but a condenser outlet, for example, is used. No warm seawater production facilities are required. Focusing on heat that has been wasted in the past, it can be said to be an excellent system that effectively uses this heat.

  In addition, since the gas turbine combustion air cooling systems 1 and 100 according to the present invention can cool the combustion air of the gas turbine in the summer when power demand is high, the amount of power generation in the turbine can be increased. Since water having a temperature of 0 ° C. or higher is used as the cooling medium for cooling the combustion air of the gas turbine, icing is not generated on the surface of the air cooler 21 and the air cooling performance is not deteriorated. Moreover, since water, such as industrial water, is used for the air cooler 21, it is not necessary to use piping which consists of expensive materials, and it is economical. Moreover, it is not necessary to change the heat medium of a vaporizer from seawater to industrial water, or from industrial water to seawater according to the temperature of the atmosphere, and cleaning of a water tank, piping, etc. accompanying these changes is unnecessary. Therefore, the gas turbine combustion air cooling systems 1 and 100 of the present invention are easy to operate and maintain throughout the year. Further, since the gas turbine combustion air cooling system 1, 100 of the present invention has a relatively simple configuration, the present invention can be applied to existing power generation facilities with simple modifications.

1 is a flowchart showing a schematic configuration of a gas turbine combustion air cooling system 1 as a first embodiment of the present invention. It is a flowchart which shows schematic structure of the cooling system 100 of the gas turbine combustion air as 2nd embodiment of this invention.

Explanation of symbols

1 Gas Turbine Combustion Air Cooling System 11 First Vaporizer 12 Second Vaporizer 21 Air Cooler 25 Water Circulation Pump 31 Water Circulation Device 35 Air Cooler Temperature Control Valve 37 Air Cooler Bypass Line 39 Vaporizer Water Supply Temperature Control Valve 41 Heat Exchanger 42 Heat Exchanger Bypass Line 51 Seawater Line 100 Gas Turbine Combustion Air Cooling System 111 First Vaporizer 112 Second Vaporizer

Claims (4)

At least two vaporizers for vaporizing a low temperature liquefied gas for fuel of a gas turbine;
An air cooler for cooling the combustion air of the gas turbine;
A water circulation line including a water circulation line capable of sending water, which is a medium for vaporizing the low-temperature liquefied gas, to the first vaporizer, and sending the cooled water as a refrigerant to the air cooler, and a water circulation pump;
A heat exchanger for heating water disposed in the middle of the water circulation line and on the outlet side of the air cooler;
Warm seawater that heats water is supplied to the heat exchanger, and the warm seawater that is heat-exchanged with the water in the heat exchanger to lower the temperature can be sent to the second vaporizer as a medium for vaporizing the low-temperature liquefied gas Seawater line,
A cooling system for air for combustion of a gas turbine, comprising: Furthermore, a heat exchanger bypass line disposed in the water circulation line that bypasses the heat exchanger;
A vaporizer water supply temperature control valve disposed in the water circulation line capable of adjusting a flow rate of water in the heat exchanger and / or the heat exchanger bypass line;
A vaporizer water supply temperature control device that detects a temperature of water supplied to the first vaporizer and outputs a control signal to the vaporizer water supply temperature control valve;
The gas turbine combustion air cooling system according to claim 1, comprising: Furthermore, an air cooler bypass line disposed in the water circulation line that bypasses the air cooler,
An air cooler temperature control valve disposed in the water circulation line capable of adjusting a flow rate of water in the air cooler and / or the air cooler bypass line;
The temperature of at least one of the outlet cooling temperature of the combustion air of the gas turbine cooled by the air cooler, the inlet air temperature of the air cooler, or the atmospheric temperature is detected, and the temperature control valve of the air cooler is detected. An air cooler temperature control device for outputting a control signal;
The gas turbine combustion air cooling system according to claim 1 or 2, characterized by comprising:   The gas turbine combustion air according to any one of claims 1 to 3, wherein the warm seawater is seawater containing warm seawater after passing through the condenser of a condenser for cooling steam. Cooling system.

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