JP6797750B2 - Horizontal exhaust condenser and steam turbine plant - Google Patents

Description

Embodiments of the present invention relate to horizontal exhaust condensers and steam turbine plants.

When the steam turbine power plant is started and stopped, a system is formed in which excess steam generated from a steam generator such as a boiler bypasses the steam turbine and is directly introduced into the condenser. At this time, the bypass steam bypassing the steam turbine is a high-temperature and high-pressure steam as compared with the exhaust steam that has worked in the steam turbine because it does not work in the steam turbine. Therefore, for the purpose of protecting the condenser, a measure is taken to reduce the temperature of the bypass steam by spraying low-temperature water into the condenser and mixing it with the bypass steam.

FIG. 7 is a diagram showing an example of a conventional downward exhaust type condenser. In the configuration of the steam turbine and the condenser, (1) the condenser main body 3 is installed below the steam turbine 1 via a connecting cylinder (also called a connecting duct, an intermediate cylinder, or an upper main body) 2, and the turbine exhaust 12 Is installed below the steam turbine 1 to condense it in water (see FIG. 7), and (2) the condenser body is installed in the axial direction of the steam turbine (the direction in which the turbine rotor extends). Alternatively, it is roughly classified into a horizontal exhaust type condenser (side exhaust type condenser) in which the condenser body is installed on the side of the steam turbine shaft.

In the lower exhaust condenser shown in FIG. 7, in order to reduce the temperature of the bypass steam 6, a turbine bypass pipe 5 is attached to a connecting cylinder 2 connecting the steam turbine 1 and the condenser main body 3, and the turbine bypass pipe 5 is attached. The spray nozzle 9 attached to the spray water pipe 8 installed above the turbine bypass nozzle with respect to the bypass steam (high temperature steam) 6 injected into the condenser main body 3 from the turbine bypass nozzle which is the ejection port of 5. More spray water (condensed water) 7 is sprayed, and the spray water 7 is mixed with the bypass steam 6 to reduce the temperature of the bypass steam 6.

In the lower exhaust type condenser shown in FIG. 7, since the cooling pipe bundle (condenser pipe bundle) 4 is provided below the steam turbine exhaust port 14, the spray water pipe 8 is provided in the vicinity of the steam turbine exhaust port 14. By installing, the direction of gravity coincides with the direction from the steam turbine exhaust port 14 toward the cooling pipe bundle 4. From this, it is possible to flow the spray water 7 from the turbine side to the entire surface of the pipe bundle side, and it is possible to mix the spray water 7 and the bypass steam 6 at the time of bypass (when the surplus steam bypasses the steam turbine). is there.

On the other hand, in the horizontal exhaust type condenser, the positional relationship between the steam turbine exhaust port and the condenser tube bundle is at the same level, and the direction of the bypass steam flow and the spray water flow is such that the bypass steam Since the spray water is orthogonal to the direction in which it falls downward under the influence of gravity, in order to sufficiently mix the bypass steam and the spray water, the spray nozzle that considers the flow of the bypass steam and the flow of the spray water is necessary. You will need it.

Japanese Unexamined Patent Publication No. 2014-190590

In the lower exhaust type condenser, in many cases, the turbine bypass pipe is introduced between the turbine exhaust port and the bundle of the condenser main body, that is, the part corresponding to the upper main body of the condenser to reduce the temperature of the bypass steam. A spray nozzle is placed near the steam turbine exhaust port for the purpose of protecting the turbine.

Further, in the horizontal exhaust type condenser, when the turbine bypass pipe is introduced between the turbine exhaust port and the bundle of the condenser main body as in the lower exhaust type condenser, the direction of the bypass steam flow and the spray. It will be orthogonal to the direction of water flow. That is, the bypass steam is attracted in the pipe bundle direction (horizontal direction) in which the cooling water flows, and the spray water is ejected in the horizontal direction from the spray nozzle and then flows down (vertically) by gravity.
In such an arrangement, in the horizontal exhaust type condenser, when the spray nozzle is arranged in the vicinity of the steam turbine exhaust port as in the lower exhaust type condenser, the spray water and the bypass steam are not mixed and the bypass steam is not mixed. It is conceivable that the temperature can not be reduced effectively. If the temperature of the bypass steam is sufficiently reduced in this way, the tube bundle of the condenser main body may be damaged by the bypass steam in a state of higher temperature and higher pressure than the turbine exhaust.

An object to be solved by the present invention is to provide a horizontal exhaust condenser and a steam turbine plant capable of effectively reducing the temperature of bypass steam.

The horizontal exhaust condenser in the embodiment includes a condenser group in which a medium for heat exchange with steam from a steam turbine passes through the inside and returns the steam to water, and a condenser main body covering the heat transfer tube group. The steam turbine is connected to the condenser main body, and has a connecting cylinder for introducing steam from the steam turbine into the condenser main body, and the steam is directed to the axial direction or the axial direction of the steam turbine. A horizontal exhaust condenser that discharges to the side, bypassing the steam turbine and sandwiching the introduction portion of the bypass steam introduced into the internal space of the connecting cylinder so as to sandwich the steam turbine side and the condensate. Each is installed on the main body side of the vessel, and has a spray water pipe that ejects spray water that cools the bypass steam toward the introduction portion of the bypass steam.

According to the present invention, the temperature of the bypass steam in the horizontal exhaust condenser can be effectively reduced.

The figure which shows the example of the turbine bypass operation in the steam turbine plant which has a horizontal exhaust type condenser in 1st Embodiment. The figure which shows an example of the cross section of the connecting cylinder in the steam turbine plant which has a horizontal exhaust type condenser in 2nd Embodiment. The figure which shows the 1st example of the turbine bypass operation in the steam turbine plant which has a horizontal exhaust type condenser in 3rd Embodiment. The figure which shows the 2nd example of the turbine bypass operation in the steam turbine plant which has a horizontal exhaust type condenser in 3rd Embodiment. The figure which shows the example of the installation of the spray water pipe which also serves as the external pressure reinforcement of the connecting cylinder in the steam turbine plant which has a horizontal exhaust type condenser in 4th Embodiment. The figure which shows the formation example of the connecting body water film in the steam turbine plant which has a horizontal exhaust type condenser in 5th Embodiment. The figure which shows an example of the conventional exhaust type condenser.

Hereinafter, embodiments will be described with reference to the drawings.
(First Embodiment)
(Constitution)
FIG. 1 is a diagram showing an example of turbine bypass operation in a steam turbine plant having a horizontal exhaust type condenser according to the first embodiment. FIG. 1A is a top view of a steam turbine plant having a horizontal exhaust condenser according to the first embodiment. FIG. 1B is a side view of a steam turbine plant having a horizontal exhaust condenser according to the first embodiment.
The steam turbine plant having the horizontal exhaust type condenser according to the first embodiment shown in FIG. 1 is a plant having a steam generator (not shown) such as a boiler, a steam turbine, and a condenser, for example, thermal power generation. It can be applied to power generation equipment, geothermal power generation equipment, and nuclear power generation equipment.

In the first embodiment, the exhaust port 14 of the steam turbine 1 faces horizontally, and the steam turbine 1 is connected to one opening of the condenser 2 via the steam turbine exhaust port 14, and the condenser 2 is connected. The condenser main body (main body of the horizontal exhaust type condenser) 3 is connected to the other opening.
The steam turbine 1 includes a turbine rotor that rotates about an axis and a casing that rotatably covers the turbine rotor. Further, a rotor of a power generation device (not shown) is connected to the turbine rotor.

The connecting cylinder 2 is located between the steam turbine 1 and the condenser main body 3 to connect the two, and introduces steam from the steam turbine 1 into the internal space of the condenser main body 3.
The condenser body 3 covers the cooling pipe bundle 4. The cooling tube bundle 4 is composed of a plurality of heat transfer tube groups that exchange heat with steam exhausted from the steam turbine 1, for example, seawater passes through the inside and condenses the steam and returns it to water.
Specifically, the connecting cylinder 2 extends from the steam turbine exhaust port 14 and connects the steam turbine exhaust port 14 with the side portion of the condenser main body 3. The connection portion of the condenser main body 3 with the connecting cylinder 2 is open, and steam flows into the condenser main body 3 through this opening. Therefore, the connecting cylinder 2 forms a part of the steam main flow path that guides the steam exhausted from the steam turbine 1 to the cooling pipe bundle in the condenser main body 3. The steam main flow path is composed of an internal space of the connecting cylinder 2 and a space inside the condenser main body 3 and between the opening of the condenser main body 3 and the cooling pipe bundle 4.

Further, below the inside of the condenser main body 3, a hot well 13 is formed in which water obtained by condensing the exhausted steam is collected. A condenser line (not shown) is connected to the lower part of the condenser main body 3, and the water collected in the hot well 13 is returned to the steam generator via the condenser line and a water supply pump (not shown).

A turbine bypass pipe 5 for introducing bypass steam 6 generated from the steam generator and bypassing the steam turbine 1 into the internal space of the connecting cylinder 2 is connected to the internal space of the connecting cylinder 2, and the turbine bypass pipe 5 is connected to the internal space of the connecting cylinder 2. The longitudinal direction is provided in the vertical direction. This bypass will be described later. Further, in the present embodiment, the steam turbine bypass pipe 5 (that is, the steam turbine 1 is bypassed) from both sides of the steam turbine 1 side (steam turbine exhaust port 14 side) and the condenser main body 3 side in the internal space of the connecting cylinder 2. The bypass steam 6 is cooled (reduced) by heat exchange with the bypass steam 6 so as to sandwich the bypass steam 6 introduced into the steam flow path between the steam turbine 1 and the condenser main body 3. A spray water pipe 8 for ejecting the spray water 7 to be heated) is provided. The spray water pipe 8 is provided with a plurality of spray nozzles 9 for ejecting the spray water 7 toward the bypass steam 6 introduced from the turbine bypass pipe 5.

In the present embodiment, in the normal operation (steady operation) state of the steam turbine 1, the steam generated from the steam generator flows into the casing of the steam turbine 1 to drive the steam turbine 1. When the steam turbine 1 is driven, power is generated by the power generation equipment.

Further, the turbine exhaust 12 discharged from the steam turbine 1 is exhausted from the steam turbine exhaust port 14 and flows in the horizontal direction, passes through the connecting cylinder 2, and flows through the cooling pipe bundle 4 in the condenser main body 3. By being cooled by the heat exchange of the above, the steam is condensed into water, accumulated in the hot well 13, and returned to the steam generator to be used again as water supply for the plant.

When the steam to be introduced into the steam turbine 1 is unnecessary, such as when the plant is started, stopped, or when the load is cut off, the steam from the steam generator is regarded as surplus steam, and this steam is not introduced into the steam turbine 1. , Turbine bypass that condenses excess steam in the cooling pipe bundle 4 in the condenser body 3 by injecting it into the internal space of the connecting cylinder 2 as bypass steam 6 that remains at a high temperature from the turbine bypass nozzle of the turbine bypass pipe 5. May drive.

In this turbine bypass operation, the spray water 7 is injected from the spray water pipe 8 into the internal space of the connecting cylinder 2 in synchronization with the injection of the bypass steam 6 from the turbine bypass pipe 5 into the internal space of the connecting cylinder 2. , The spray water 7 is brought into contact with the bypass steam 6. As a result, the spray water is sandwiched between the bypass steam 6 from both ends of the steam turbine 1 side (steam turbine exhaust port 14 side) and the end of the condenser body 3 side in the internal space of the connecting cylinder 2. 7 is injected to bring it into contact with the bypass steam 6 to reduce the temperature of the bypass steam 6.

The bypass steam 6 whose temperature has been reduced by the spray water 7 is condensed into water by the cooling pipe bundle 4 in the condenser main body 3 and accumulated in the hot well 13 as the water supply for the plant, as in the turbine exhaust 12 described above. Will be used again.

In the present embodiment, the condenser main body is installed on the side surface of the steam turbine shaft, and the horizontal exhaust type condenser in which the turbine exhaust is exhausted laterally with respect to the axial direction is shown, but the condenser is not limited to this. The water vessel main body may be installed in the turbine axial direction, and the turbine exhaust may be a horizontal exhaust type condenser that is exhausted in the axial direction.

(Action)
In the turbine bypass operation of steam, the bypass steam 6 is injected at high speed from the turbine bypass nozzle while maintaining a high temperature, so that the steam diffuses into the cooling pipe bundle 4 and the connecting cylinder 2 in the condenser main body 3, and further communicates. Steam also diffuses into the steam turbine 1 through the body 2, and finally, this heat may cause damage to each part.

As shown in FIG. 1, in the present embodiment, the spray water pipe 8 is installed so as to sandwich the turbine bypass pipe 5 from both sides of the end portion on the steam turbine 1 side and the end portion on the condenser main body 3 side. When the bypass steam 6 flowing through the cooling pipe bundle 4 in the connecting cylinder 2 and the condenser main body 3 comes into contact with the spray water 7, the bypass steam 6 is cooled from the overheated state, so that the bypass steam 6 cools the condenser. The temperature inside will not rise abnormally. Therefore, damage to the device can be prevented.

(effect)
In this way, in the horizontal exhaust type condenser, the spray water pipe 8 is arranged so as to sandwich the turbine bypass pipe 5 from the condenser side and the steam turbine side, so that the bypass steam 6 injected during the turbine bypass operation To realize a steam turbine plant that performs turbine bypass operation that enables uniform contact with the spray water 7, effectively reduces the temperature of the bypass steam, and prevents damage to the condenser tube bundle due to the bypass steam. Can be done.

(Second Embodiment)
Next, the second embodiment will be described with reference to FIGS. 1 and 2. The detailed description of the part similar to the first embodiment in each of the following embodiments will be omitted. FIG. 2 is a diagram showing an example of a cross section of a connecting cylinder in a steam turbine plant having a horizontal exhaust condenser in the second embodiment. FIG. 2 shows an example of arrangement of the spray water pipe 8 and the spray nozzle 9 installed in the internal space of the connecting cylinder 2 in the cross section of the connecting cylinder 2.

In the second embodiment, the spray water pipe 8 and the spray nozzle 9 are not evenly arranged from above to below the internal space of the connecting cylinder 2, but are arranged so as to be biased upward in the internal space of the connecting cylinder 2. To.

(Action)
As described above, in the second embodiment, since the spray water pipe 8 and the spray nozzle 9 are arranged so as to be biased upward of the connecting cylinder 2, the spray water 7 affected by falling downward due to gravity is transferred to the connecting cylinder 2. It is possible to spray a sufficient amount of water even above 2.
Further, in the second embodiment, under the condition that the number of spray nozzles 9 is the same, the number of spray nozzles 9 arranged below the connecting cylinder 2 is smaller than that in the first embodiment. The spray water sprayed downward is (1) spray water 7 sprayed from the spray nozzle 9 arranged below, and (2) sprayed from the spray nozzle 9 installed above the connecting cylinder 2. There is a spray water 7 that is sprayed and falls downward due to gravity. Therefore, even if the number of spray nozzles 9 arranged below the connecting cylinder 2 is small, the temperature of the bypass steam 6 is reduced by the contact between the bypass steam 6 injected from the turbine bypass pipe 5 and the spray water 7. Occurs.

(effect)
In this way, in the horizontal exhaust type condenser, the spray water pipe 8 is arranged so as to sandwich the turbine bypass pipe 5 from both sides of the condenser side and the steam turbine side, and the spray water pipe 8 and the spray nozzle 9 are arranged. In addition to the effects described in the first embodiment, the bypass steam 6 injected during the turbine bypass operation and the spray water 7 can be evenly contacted with each other. It is possible to realize a steam turbine plant that performs turbine bypass operation that can evenly reduce the temperature of the bypass steam and prevent damage to the condenser tube bundle due to the bypass steam 6.

(Third Embodiment)
Next, the third embodiment will be described with reference to FIGS. 3 and 4. FIG. 3 is a diagram showing a first example of turbine bypass operation in a steam turbine plant having a horizontal exhaust condenser in the third embodiment. FIG. 3A is a top view of a first example of a steam turbine plant having a horizontal exhaust condenser according to a third embodiment. FIG. 3B is a side view of a first example of a steam turbine plant having a horizontal exhaust condenser according to the first embodiment.
FIG. 4 is a diagram showing a second example of turbine bypass operation in a steam turbine plant having a horizontal exhaust type condenser according to the third embodiment. FIG. 4A is a top view of a second example of a steam turbine plant having a horizontal exhaust condenser according to a third embodiment. FIG. 4B is a side view of a second example of a steam turbine plant having a horizontal exhaust condenser according to a third embodiment.

In this third embodiment, the introduction position of the turbine bypass pipe 5 with respect to the connecting cylinder 2 and the direction in which the bypass steam 6 flows from the turbine bypass pipe 5 into the connecting cylinder 2 are different in the first and second embodiments. This is an example showing a case. As shown here, the introduction position and method of the turbine bypass pipe 5 into the connecting cylinder 2 shown in the first and second embodiments are not particularly limited.

(Action)
In the first and second embodiments described above, the turbine bypass pipe 5 is introduced so that the longitudinal direction is vertical from the upper surface of the connecting cylinder 2.
On the other hand, as shown in FIGS. 3 and 4, in the third embodiment, the turbine bypass pipe 5 is introduced so that the longitudinal direction is horizontal from the side surface of the connecting cylinder 2.
Specifically, in the example shown in FIG. 3, the turbine bypass pipe 5 is arranged substantially in the center of the connecting cylinder 2 and has an upward facing turbine bypass nozzle and a downward facing turbine bypass nozzle, and these turbine bypasses. Bypass steam 6 is injected vertically in the connecting cylinder 2 from the nozzle.
On the other hand, in the example shown in FIG. 4, the turbine bypass pipe 5 is provided with a turbine bypass nozzle that is arranged above the connecting cylinder 2 and faces downward, and the bypass steam 6 is supplied from the turbine bypass nozzle in the connecting cylinder 2. It is sprayed downward.
The arrangement of the spray water pipe 8 and the spray nozzle 9 in the third embodiment is the same as in the first and second embodiments.

(effect)
Similar to the first and second embodiments, in the third embodiment, the bypass steam 6 injected during the turbine bypass operation and the spray water 7 can be evenly contacted, and the bypass steam can be effectively used. It is possible to realize a steam turbine plant that performs turbine bypass operation that can reduce the temperature and prevent damage to the condenser tube bundle due to bypass steam.

(Fourth Embodiment)
Next, the fourth embodiment will be described with reference to FIG. FIG. 5 is a diagram showing an example of installation of a spray water pipe that also serves as external pressure reinforcement of a connecting cylinder in a steam turbine plant having a horizontal exhaust type condenser according to the fourth embodiment.
As shown in FIG. 5, in the fourth embodiment, this joining is performed by rigidly joining a part or all of the spray water pipe 8 described in the second embodiment to the inner surface of the connecting cylinder 2. The spray water pipe 8 is also used as the connecting cylinder external pressure reinforcing pipe 10 for maintaining the structural strength of the connecting cylinder 2, and the spray nozzle 9 is attached to the connecting cylinder external pressure reinforcing pipe 10.

(Action)
The condenser is operated at a negative pressure with respect to the atmospheric pressure, but a reinforcing structure that resists the external pressure acting on the connecting cylinder 2 is required. Therefore, in the fourth embodiment, as a reinforcing structure in the horizontal exhaust type condenser, a part or all of the spray water pipe 8 is rigidly joined to the connecting cylinder 2 to rigidly join the spray water pipe 8 to the spray water 7 Can be supplied into the connecting cylinder 2 and the structural strength of the connecting cylinder 2 can be maintained.

During normal operation, when the turbine exhaust (exhaust steam) 12 of the steam turbine 1 passes through the connecting cylinder 2, a pressure loss is caused by a structure installed in the connecting cylinder 2. When the member for maintaining the structural strength of the connecting cylinder 2 and the spray water pipe 8 are installed independently, a pressure loss occurs in each of them. On the other hand, as in the fourth embodiment, the pressure loss is reduced by using both the member for maintaining the structural strength of the connecting cylinder 2 and the spray water pipe 8.

(effect)
In the fourth embodiment, in addition to the same effects as those of the first and second embodiments, a part or all of the spray water pipe 8 is also used as the connecting cylinder external pressure reinforcing pipe 10, so that the connecting cylinder 2 and the spray water pipe are used. It is possible to reduce the quantity of 8 items. Further, since the number of members installed in the connecting cylinder 2 can be reduced, it is possible to reduce the pressure loss of the steam exhausted from the steam turbine 1 during normal operation.

(Fifth Embodiment)
The fifth embodiment will be described with reference to FIG. FIG. 6 is a diagram showing an example of forming a connecting body water film in a steam turbine plant having a horizontal exhaust type condenser according to the fifth embodiment. This fifth embodiment further prevents the body plate of the connecting cylinder 2 and the reinforcing member inside the connecting cylinder from being heated by the bypass steam 6 introduced into the connecting cylinder 2 in the first to fourth embodiments. It is a technology aimed at that.

In the fifth embodiment, the spray water 7 is sprayed from the spray nozzles 9 described in the first to fourth embodiments toward the inner surface of the connecting cylinder 2 and sprayed on the inner surface of the connecting cylinder 2. Water 7 is sprayed. In the example shown in FIG. 6, an example in which the spray water 7 is sprayed on the inner surface of the connecting cylinder 2 is shown, but the present invention is not limited to this, and the spray water 7 is sprayed on the cooling pipe bundle 4 in the condenser main body 3. Alternatively, the spray water 7 may be sprayed onto another structure installed in the condenser.

(Action)
When the spray water 7 is sprayed onto the inner surface of the connecting cylinder 2 and the water film 11 is formed on the inner surface as in the fifth embodiment, the high temperature bypass steam 6 jetted from the turbine bypass pipe 5 is formed. On the other hand, since the connecting cylinder 2 is protected by the water film 11, it is possible to suppress the temperature rise of the connecting cylinder 2. The same applies when the spray water 7 is sprayed onto the cooling pipe bundle 4 and other structures in the condenser main body 3.

(effect)
As in the fifth embodiment, the temperature rise of this concept can be suppressed by injecting spray water 7 onto the structure in contact with the high-temperature bypass steam 6 to form a water film on the structure. This makes it possible to prevent damage caused by the high temperature bypass steam 6.

Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are also included in the scope of the invention described in the claims and the equivalent scope thereof.

1 ... Steam turbine, 2 ... Connecting cylinder, 3 ... Condenser body, 4 ... Cooling pipe bundle, 5 ... Turbine bypass pipe, 6 ... Bypass steam, 7 ... Spray water, 8 ... Spray water pipe, 9 ... Spray nozzle, 10 ... communication body external pressure reinforcement pipe, 11 ... water film, 12 ... turbine exhaust, 13 ... hot well, 14 ... steam turbine exhaust port.

Claims (5)

A medium that exchanges heat with steam from a steam turbine passes through the inside, and has a heat transfer tube group that returns the steam to water and a condenser body that covers the heat transfer tube group, and the steam turbine and the condenser body. A horizontal exhaust type condenser that is connected to and has a connecting cylinder that introduces steam from the steam turbine into the condenser body, and discharges the steam in the axial direction of the steam turbine or laterally with respect to the axial direction. And
It is installed on the steam turbine side and the condenser main body side so as to sandwich the bypass steam introduction portion that bypasses the steam turbine and is introduced into the internal space of the connecting cylinder, and is installed in the bypass steam introduction portion. A horizontal exhaust type condenser provided with a spray water pipe that ejects spray water that cools the bypass steam toward the steam. The horizontal exhaust type condenser according to claim 1, wherein the spray water pipe is installed so as to be biased upward in the internal space of the connecting cylinder. The horizontal exhaust type condenser according to claim 1 or 2, wherein the spray water pipe also serves as a reinforcing member for the connecting cylinder. The spray water pipe
The horizontal exhaust type condenser according to any one of claims 1 to 3, wherein a water film is formed on the structure to which the spray water is sprayed by spraying the spray water onto the structure in contact with the bypass steam. .. The horizontal exhaust type condenser according to claim 1 and
A steam turbine plant including the steam turbine.