JP7206990B2 - Heat transfer tube damage detection device, boiler system, and heat transfer tube damage detection method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a heat transfer tube damage detection device, a boiler system, and a heat transfer tube damage detection method.

In a heat exchange device such as a boiler, the leaked steam due to damaged heat transfer tubes also damages the surrounding heat transfer tubes, so early detection and stoppage are required. Generally, in a heat exchange device, damage to heat transfer tubes is detected based on changes in the amount of water supplied to the heat transfer tubes. Further, for example, Patent Literature 1 discloses a technique for detecting tube leaks (leakage from fluid piping) based on acoustic signals in heat exchange equipment. In Patent Literature 1, sound emitted from a fluid pipe is collected, and tube leak is detected based on changes in the sound signal.

International Publication No. 2013/136472

However, when detecting damage to the heat transfer tubes based on changes in the amount of water supply, it takes time from the occurrence of damage to the heat transfer tubes until the amount of water supply changes, resulting in a large time lag in detecting damage to the heat transfer tubes. do. Further, when detecting damage to heat transfer tubes based on changes in acoustic signals of the heat transfer tubes (acoustic method), it is difficult to identify the damaged heat transfer tubes, and the identification takes time. Furthermore, the boiler is provided with a high-pressure washer (soot blower) to remove dust from the surfaces of the heat transfer tubes. In the case of the acoustic method, it is difficult to detect damage to the heat transfer tubes because the operation noise of the high pressure washers interferes with the operation unless all the high pressure washers are stopped.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and an object of the present invention is to quickly detect damage to heat transfer tubes.

The present invention is a heat transfer tube damage detection device for detecting damage to a heat transfer tube of a heat exchange device provided with a plurality of heat transfer tubes as a first means related to a heat transfer tube damage detection device for solving the above problems. a measuring means provided at a position where the behavior of the fluid flowing inside is similar in the plurality of heat transfer tubes, and measuring the state quantity in the heat transfer tubes; and damage determination means for determining damage to the heat transfer tubes.

As a second means related to a heat transfer tube damage detection device, a heat transfer tube damage detection device for detecting damage to a heat transfer tube of a heat exchange device provided with a plurality of heat transfer tubes, wherein the plurality of heat transfer tube damage detection devices are connected to the same header. In the heat transfer tube, measuring means are provided at equal positions when viewed in the longitudinal direction of the header and measure state quantities in the heat transfer tube, and based on inputs from the plurality of measuring means, the heat transfer tube and a damage determination means for determining damage of the.

As a third means relating to the heat transfer tube damage detection device, a configuration is adopted in which the state quantity is temperature as the first or second means.

As a fourth means related to a heat transfer tube damage detection device, in any one of the first to third means, the heat exchange device is provided in a boiler, and the measuring means measures the heat transfer tube from the wall portion of the boiler. A configuration in which it is provided in a region exposed to the outside is adopted.

As a fifth means relating to the heat transfer tube damage detection device, in the fourth means, a configuration is adopted in which the measuring means is provided up to the connecting portion of the outlet header.

As a sixth means relating to the heat transfer tube damage detection device, in any one of the first to fifth means, the damage determination means determines that the heat transfer tube is damaged based on the correlation of the measured values from the plurality of measurement means. A configuration is adopted in which it is determined that the

As a seventh means relating to the heat transfer tube damage detection device, in the sixth means, the damage determination means determines that the heat transfer tube is damaged when a difference between the measured values from the plurality of measurement means exceeds a threshold. A configuration of determining is adopted.

As an eighth means relating to the heat transfer tube damage detection device, in the sixth means, the damage determination means includes a data group formed by accumulating measurement values from a plurality of the measurement means, and the most recent A configuration is adopted in which the damage to the heat transfer tubes is determined based on the Mahalavinos distance from the measured value.

A boiler system comprising the heat transfer tube damage detection device according to any one of claims 1 to 6 as first means relating to the boiler system.

As a first means related to the heat transfer tube damage detection method, a heat transfer tube damage detection method for a heat exchanger provided with a plurality of heat transfer tubes, comprising a measurement step of measuring state quantities of the plurality of heat transfer tubes, and the measurement step. and a damage determination step of determining damage to the heat transfer tube based on the plurality of measured values detected in.

According to the present invention, since the damage to the heat transfer tubes is detected based on the temperature change of the heat transfer tubes, the time taken from the occurrence of the damage to the heat transfer tubes to the detection of the damage is short. Furthermore, unlike the acoustic method, even when the soot blower is in operation, it is possible to detect damage to the heat transfer tube except in the vicinity of the target heat transfer tube. Therefore, the present invention can quickly and accurately detect damage to heat transfer tubes.

It is a mimetic diagram showing the whole boiler in one embodiment of the present invention. 1 is a schematic diagram showing heat transfer tubes and heat transfer plates of a boiler according to an embodiment of the present invention; FIG. 1 is a schematic diagram showing the arrangement of heat transfer plates of a boiler in one embodiment of the present invention; FIG. 1 is a block diagram of a heat transfer tube damage detection device according to an embodiment of the present invention; FIG. 4 is a graph showing temperature behavior of each heat transfer tube when the heat transfer tube is damaged in one embodiment of the present invention.

An embodiment of a heat transfer tube damage detection device and a heat transfer tube flaw detection method according to the present invention will be described below with reference to the drawings.

A heat transfer tube damage detection device 1 according to the present embodiment is provided for a boiler system 100 . First, an outline of the boiler system 100 will be described with reference to FIGS. 1 to 3. FIG.
The boiler system 100, as shown in FIG. , a reheater 180 , an economizer 190 , and a heat transfer tube damage detection device 1 . Although not shown, the boiler system 100 is provided with a soot blower for removing dust and the like adhering to the surfaces of the heat transfer tubes. A soot blower injects high-pressure steam onto the heat transfer tube surface.

The furnace 110 is composed of a cylindrical furnace wall erected in a vertical direction, and generates combustion heat by burning fuel such as pulverized coal therein. In the furnace 110, high-temperature combustion gas generated by burning fuel flows upward in the vertical direction.

The flue 120 is a cylindrical member that extends horizontally from the top of the furnace 110 and has a downstream end that extends vertically downward. Combustion gas generated in the furnace 110 flows into the flue 120 . Further, the flue 120 is provided with a partition wall formed along the flow direction at the downstream end, and the internal flow path is divided into two on the downstream side.

A plurality of burners 130 are installed in the circumferential direction of the furnace 110 on the lower wall portion of the furnace 110 . Although not shown, a plurality of burners 130 are also installed in the vertical direction of the furnace 110 . The burner 130 injects fuel (pulverized coal, liquid fuel, etc.) into the furnace 110 to burn it. The burner 130 also supplies fuel and heated air toward the furnace 110 .

The furnace wall heat transfer tube 140 is a pipe wound along the inner wall of the furnace 110 in the vicinity of the burner 130 . The steam that has passed through the economizer 190 is supplied to the furnace wall heat transfer tubes 140 , and the steam is heated by the combustion gas in the furnace 110 .

The primary superheater 150 is provided in the channel on one side of the downstream end of the flue 120, and as shown in FIG. ing. As shown in FIG. 3, the primary superheater 150 is constructed by arranging a plurality of heat transfer plates in parallel, each of which is connected to a header K. As shown in FIG. The primary superheater 150 is supplied with the steam that has passed through the furnace wall heat transfer tubes 140, and heats the steam by the combustion gas passing through the flue 120 to bring it into a superheated state. Also, the header K is provided outside the wall of the flue 120 .

The secondary superheater 160 is provided in the upper part of the furnace 110 and, like the primary superheater 150, is configured by parallelly arranging heat transfer plates composed of a plurality of heat transfer tubes. The secondary superheater 160 is supplied with the superheated steam that has passed through the primary superheater 150 , and heats the superheated steam with the combustion gas that passes through the upper part of the furnace 110 . In the secondary superheater 160, a plurality of heat transfer plates are connected to the headers on the upstream and downstream sides, and steam is supplied from the upstream header and collected by the downstream header. be done. A header of the secondary superheater 160 is provided outside the ceiling wall of the furnace 110 .

The final superheater 170 is provided in the vicinity of the upstream end of the flue 120, and, like the primary superheater 150, is configured by parallelly arranging heat transfer plates composed of a plurality of heat transfer tubes. The final superheater 170 is supplied with superheated steam that has passed through the secondary superheater 160 , and further heats the superheated steam by the combustion gas flowing into the flue 120 . A final superheater 170 supplies steam to a steam turbine (not shown). In the final superheater 170, a plurality of heat transfer plates are connected to the headers on the upstream and downstream sides, and steam is supplied from the upstream header and collected by the downstream header. be. Also, the header of the final superheater 170 is provided outside the wall of the flue 120 .

The reheater 180 is provided in the flow path on the other side of the downstream end of the flue 120, and, similar to the primary superheater 150, heat transfer plates composed of a plurality of heat transfer tubes are arranged in parallel. It is configured. The reheater 180 is supplied with steam discharged from a steam turbine (not shown) and heats the discharged steam again with combustion gas. The reheater 180 also supplies steam to a reheat turbine (not shown). In the reheater 180, a plurality of heat transfer plates are connected to headers on the upstream and downstream sides, and steam is supplied from the upstream header and collected by the downstream header. be. Also, the header of the reheater 180 is provided outside the wall of the flue 120 .

The economizer 190 is provided on the upper stage of the furnace wall heat transfer tubes 140, and is configured by disposing heat transfer plates formed of a plurality of heat transfer tubes in parallel. The economizer 190 generates steam by heating liquid water supplied from the outside with combustion gas. In the economizer 190, a plurality of heat transfer plates are connected to headers on the upstream and downstream sides, and steam is supplied from the upstream header and collected by the downstream header. be. Also, the header of the economizer 190 is provided outside the wall of the flue 120 .

Next, the heat transfer tube damage detection device 1 will be described with reference to FIGS. 3 and 4. FIG.
A heat transfer tube damage detection device 1 includes a plurality of temperature sensors 2 (measurement means), a temperature information storage section 3 , a temperature information analysis section 4 and a damage determination section 5 . The heat transfer tube damage detection device 1 is installed as one function of a computer, and is composed of a CPU, a memory, a hard disk, and the like. Moreover, the temperature information storage unit 3, the temperature information analysis unit 4, and the damage determination unit 5 constitute damage determination means in the present invention.

The temperature sensor 2 is attached to a plurality of heat transfer plates provided in a heat exchange device in which heat transfer tubes are arranged, such as the primary superheater 150, the secondary superheater 160, the final superheater 170, the reheater 180, and the economizer 190. It is provided to measure the temperature (state quantity) of the heat transfer tube surface. As shown in FIG. 3, the temperature sensors 2 are provided at regular intervals for each of the plurality of heat transfer plates. In addition, the temperature sensor 2 is located at the same distance from the header so that the temperature behavior of the fluid is similar to the heat transfer plates connected to the same header, and the influence from the combustion gas is the same. provided in Specifically, the temperature sensor 2 is provided between the ceiling wall of the furnace 110 and the header in the secondary superheater 160, the primary superheater 150, the final superheater 170, the reheater 180, and the economizer 190. is provided between the wall of the flue 120 and the header. The temperature sensors 2 provided on the heat transfer plates connected to the same header are provided parallel to each other when viewed from the longitudinal direction of the header.

The temperature information storage unit 3 acquires temperature data from each temperature sensor 2 and stores the temperature data for each heat exchange device.
The temperature information analysis unit 4 of this embodiment analyzes temperature data based on the Mahalabinos-Taguchi method (MT method). Specifically, the temperature information analysis unit 4 reads the temperature data stored in the temperature information storage unit 3 for each heat exchange device, and accumulates the temperature data acquired from the plurality of temperature sensors 2 provided in each heat exchange device. Define the unit space of the data group composed of temperature data. Further, the temperature information analysis unit 4 calculates the distance (Maharabinos distance) between the unit space and the newly added latest temperature data coordinates.

The damage determination unit 5 determines whether or not there is an abnormality based on the Mahalabinos distance calculated by the temperature information analysis unit 4 . Specifically, based on a predetermined threshold, the damage determination unit 5 determines that there is an abnormality when the calculated Mahalabino's distance is greater than the threshold.

Next, a method for detecting damage to heat transfer tubes will be described, taking the case of detection in the primary superheater 150 as an example.
Each temperature sensor 2 always measures the temperature of the heat transfer tube D (measurement step). In general, the temperature behaviors detected in adjacent heat transfer panels connected to the same header tend to be similar due to the similar effects of inlet temperatures and combustion gases of the heat transfer panels. And if damage occurs to the heat transfer panel, this similar behavior is lost.
Temperature data on the surface of the heat transfer tube D measured by the temperature sensor 2 is always recorded in the temperature information storage unit 3 . The temperature information analysis unit 4 reads the temperature data from the temperature information storage unit 3, and uses the temperature data obtained from the plurality of temperature sensors 2 provided in each heat exchange device to determine the temperature between the temperature sensors 2 adjacent to each other. It defines the unit space of the data group composed of data. Furthermore, the temperature information analysis unit 4 calculates the distance (Maharabinos distance) between the unit space and the temperature data newly acquired from the temperature sensor 2 .

By the way, regarding the heat transfer plates P of each heat exchange device, there is a correlation between the distance between the heat transfer plates P and the temperature behavior. Specifically, the temperature behaviors of the adjacent heat transfer plates P tend to be highly similar, and the heat transfer plates P provided at positions apart from each other tend to have low similarity. On the other hand, when the heat transfer plate P is damaged, the temperature behavior of the damaged heat transfer plate P changes greatly, and as shown by the dashed line in FIG. The temperature of the heat transfer plate P changes. Therefore, when a certain heat transfer plate P is damaged or when an adjacent heat transfer plate P is damaged, the Mahalabinos distance increases.

The damage determination unit 5 determines whether or not the calculated Mahalabino's distance exceeds the threshold value based on the correlation (damage determination step). When the calculated Mahalabino's distance exceeds the threshold, the damage determination unit 5 determines that damage has occurred in the vicinity of the heat transfer plate P, and issues a warning to an external device or the like.

According to the heat transfer tube damage detection device 1 according to this embodiment, it is possible to quickly and accurately detect heat transfer tube damage by comparing temperature behaviors of a plurality of heat transfer tubes. Therefore, when the heat transfer tube is damaged, the damage can be detected quickly, and recovery from the heat transfer tube damage can be expedited. Furthermore, the heat transfer tube damage detection device 1 can always detect heat transfer tube damage except when the soot blower is operating in the target heat exchange device.

Further, according to the heat transfer tube damage detection device 1 according to the present embodiment, the temperature sensor 2 is located at a position where the temperature behavior is similar in a plurality of heat transfer tubes connected to the same header, that is, in the longitudinal direction of the header. are located at the same position when viewed from the Therefore, the temperature detected by the temperature sensor 2 is similar in adjacent heat transfer tubes, and it is easy to detect temperature abnormalities in the heat transfer tubes.

Further, according to the heat transfer tube damage detection device 1 according to the present embodiment, the Mahalavinos distance between the temperature data group acquired from the adjacent temperature sensors 2 and the temperature data newly acquired from the temperature sensor 2 is calculated. , to determine whether damage has occurred. Therefore, it is possible to obtain the change in the temperature behavior of each heat transfer tube from the Mahalabinos distance. Therefore, when the heat transfer tube is damaged, the damage can be quickly detected.

In addition, the boiler system 100 includes a heat exchange device that includes a plurality of heat transfer panels arranged in parallel. Adjacent heat transfer panels have similar inlet temperatures and combustion gas temperatures. The temperature behavior tends to be similar. Therefore, it is possible to adopt the heat transfer tube damage detection method as in this embodiment.

Although the preferred embodiments of the present invention have been described above with reference to the drawings, the present invention is not limited to the above embodiments. The various shapes, combinations, and the like of the constituent members shown in the above-described embodiment are merely examples, and can be variously changed based on design requirements and the like without departing from the gist of the present invention.

In the above embodiment, the temperature sensors 2 are provided at equal intervals for each of the plurality of heat transfer plates, but the present invention is not limited to this. The temperature sensors 2 may be provided on all heat transfer plates. This makes it easy to detect which heat transfer plate is damaged.

Further, a temperature sensor may be provided for each of the plurality of heat transfer tubes forming the heat transfer plate. In this case, it is possible to detect which heat transfer tube in the heat transfer plate is damaged.

Further, in the above embodiment, damage to the heat transfer tubes is detected based on the MT method, but the present invention is not limited to this. For example, a difference between temperature data of adjacent temperature sensors may be calculated, and it may be determined that the heat transfer tube is damaged when the difference is larger than a threshold value.

Moreover, although the configuration applied to the boiler system 100 has been described in the above embodiment, the present invention is not limited to this. In the heat transfer tube damage detection device, a plurality of heat transfer tubes are provided in parallel, so that the temperature behavior of the fluid flowing outside the heat transfer tubes (corresponding to the combustion gas in this embodiment) is similar, and The application is not limited as long as the heat exchanger tubes have similar inlet temperatures.

Further, in the above embodiment, the measuring means measures the heat transfer tube temperature, but the present invention is not limited to this, and the measuring means may measure the pressure inside the heat transfer tube. In this case, for example, a pressure sensor is provided at the header K connected to the upstream side of the heat transfer tube and the header K connected to the downstream side, and calculates the difference between the pressure on the upstream side and the pressure on the downstream side. Damage to the heat transfer tubes can be detected by detecting changes in the differential pressure.

1 heat transfer tube damage detection device 2 temperature sensor 3 temperature information storage unit 4 temperature information analysis unit 5 damage determination unit

Claims (9)

A heat transfer tube damage detection device for detecting damage to a heat transfer tube of a heat exchange device provided with a plurality of heat transfer tubes,
a measuring means provided at a position where the behavior of the fluid flowing inside the plurality of heat transfer tubes resembles each other, and measuring a state quantity in the heat transfer tubes;
damage determination means for determining damage to the heat transfer tubes based on inputs from the plurality of measurement means ;
The heat transfer tube damage detection device , wherein the damage determination means determines that the heat transfer tube is damaged based on the correlation of the measured values from the plurality of measurement means . A heat transfer tube damage detection device for detecting damage to a heat transfer tube of a heat exchange device provided with a plurality of heat transfer tubes,
measuring means provided at equal positions in a plurality of heat transfer tubes connected to the same header when viewed from the length direction of the header and measuring state quantities in the heat transfer tubes;
and damage determination means for determining damage to the heat transfer tubes based on inputs from the plurality of measurement means. 3. The heat transfer tube damage detection device according to claim 1, wherein the state quantity is temperature. The heat exchange device is provided in a boiler, and the measuring means is provided in a region of the heat transfer tube that is exposed to the outside from the wall of the boiler. The heat transfer tube damage detection device according to . 5. The heat transfer tube damage detection device according to claim 4, wherein the measuring means is provided up to the connecting portion of the outlet header. 2. The heat transfer tube damage detection device according to claim 1, wherein the damage determination means determines that the heat transfer tube is damaged when a difference between the measured values from the plurality of measurement means exceeds a threshold value . The damage determination means determines damage to the heat transfer tubes based on a data group formed by accumulating measured values from a plurality of the measuring means and a Mahalbinos distance between the most recent measured value. The heat transfer tube damage detection device according to claim 1 . A boiler system comprising the heat transfer tube damage detection device according to any one of claims 1 to 7. A heat transfer tube damage detection method for a heat exchange device provided with a plurality of heat transfer tubes,
a measurement step of measuring state quantities of a plurality of heat transfer tubes;
a damage determination step of determining damage to the heat transfer tube based on a plurality of measured values detected in the measurement step;
The heat transfer tube damage detection method, wherein, in the damage determination step, it is determined that the heat transfer tubes are damaged based on a correlation of the measured values of the plurality of heat transfer tubes.

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