JP2020133962A - Heat transfer pipe damage detection device, boiler system and heat transfer pipe damage detection method - Google Patents

Abstract

To detect damage of a heat transfer pipe quickly.SOLUTION: A heat transfer pipe damage detection device that detects damage of a heat transfer pipe of a heat exchange device provided with a plurality of heat transfer pipes, comprises: a measurement means that is provided at a position where the behavior of fluid flowing inside is similar in the plurality of heat transfer pipes, and measures a temperature or pressure in the heat transfer pipe; and a damage determination means that determines damage of the heat transfer pipe based on inputs from the plurality of measurement means.SELECTED DRAWING: Figure 1

Description

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, leaked steam due to damage to the heat transfer tube also damages the surrounding heat transfer tube, so early detection and can stop are required. Generally, in a heat exchanger, damage to a heat transfer tube is detected based on a change in the amount of water supplied to the heat transfer tube. Further, for example, Patent Document 1 discloses a method of detecting a tube leak (leakage from a fluid pipe) based on an acoustic signal in a heat exchange device. In Patent Document 1, a sound emitted from a fluid pipe is collected, and a tube leak is detected based on a change in the acoustic signal.

International Publication No. 2013/136472

However, when the damage of the heat transfer tube is detected based on the change of the water supply amount, it takes time from the occurrence of the damage in the heat transfer tube to the change of the water supply amount, so that a large time lag occurs in the detection of the damage of the heat transfer tube. To do. Further, when the damage of the heat transfer tube is detected based on the change of the acoustic signal of the heat transfer tube (acoustic method), it is difficult to identify the damaged heat transfer tube, and it takes time to identify the damaged heat transfer tube. Further, the boiler is provided with a high pressure washer (soothing blower) in order to remove dust on the surface of the heat transfer tube. In the case of the acoustic method, it is difficult to detect damage to the heat transfer tube because it is hindered by the operating noise of the high pressure washer except when all the high pressure washers are stopped.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to quickly detect damage to a heat transfer tube.

The present invention is a heat transfer tube damage detecting device for detecting damage to the heat transfer tube of a heat exchange device provided with a plurality of heat transfer tubes as a first means relating to the heat transfer tube damage detecting device for solving the above problems. Therefore, the above-mentioned is provided at a position where the behavior of the fluid flowing inside in the plurality of heat transfer tubes is similar, and based on the measurement means for measuring the state amount in the heat transfer tube and the input from the plurality of the measurement means. A configuration is adopted in which a damage determining means for determining damage to the heat transfer tube is provided.

As a second means relating to the heat transfer tube damage detecting device, a plurality of heat transfer tube damage detecting devices for detecting damage to the heat transfer tube of a heat exchange device provided with a plurality of heat transfer tubes, which are connected to the same tube approach. In the heat transfer tube of the above, the heat transfer tube is provided at the same position when viewed from the length direction of the tube approach and is based on the measuring means for measuring the state amount in the heat transfer tube and the inputs from the plurality of the measuring means. A configuration is adopted in which a damage determining means for determining the damage of the above is provided.

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

As a fourth means relating to the heat transfer tube damage detecting device, in any of the above 1 to 3 means, the heat exchange device is provided in the boiler, and the measuring means is installed from the wall portion of the boiler of the heat transfer tube. A configuration is adopted in which the area is provided in an area exposed to the outside.

As a fifth means relating to the heat transfer tube damage detecting device, in the fourth means, the measuring means is provided between the connecting portion of the outlet pipe.

As a sixth means relating to the heat transfer tube damage detecting device, in any one of the first to fifth means, the damage determining means damages the heat transfer tube based on the correlation of the measured values from the plurality of measuring means. Adopt the configuration that it is judged that it has been done.

As a seventh means relating to the heat transfer tube damage detecting device, in the sixth means, the damage determining means damages the heat transfer tube when the difference between the measured values from the plurality of measuring means exceeds the threshold value. Is adopted.

As an eighth means relating to the heat transfer tube damage detecting device, in the sixth means, the damage determining means is a data group formed by accumulating measured values from a plurality of the measuring means, and the latest one. A configuration is adopted in which damage to the heat transfer tube is determined based on the Mahalanobis distance from the measured value.

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

As the first means related to the heat transfer tube damage detection method, there is a heat transfer tube damage detection method of a heat exchange device provided with a plurality of heat transfer tubes, wherein a measurement step of measuring the state amount of the plurality of heat transfer tubes and the measurement step A configuration is adopted in which a damage determination step of determining damage to the heat transfer tube is provided based on a plurality of measured values detected in.

According to the present invention, since damage to the heat transfer tube is detected based on the temperature change of the heat transfer tube, the time required from the damage to the heat transfer tube to the detection of the damage is short. Further, unlike the acoustic method, even when the soot blower is operating, 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 the heat transfer tube.

It is a schematic diagram which shows the whole of the boiler in one Embodiment of this invention. It is a schematic diagram which shows the heat transfer tube and heat transfer plate of the boiler in one Embodiment of this invention. It is a schematic diagram which shows the arrangement of the heat transfer plate of the boiler in one Embodiment of this invention. It is a block diagram of the heat transfer tube damage detection apparatus which concerns on one Embodiment of this invention. It is a graph which shows the temperature behavior of each heat transfer tube at the time of the heat transfer tube damage in one Embodiment of this invention.

Hereinafter, an embodiment of the heat transfer tube damage detection device and the heat transfer tube flaw detection detection method according to the present invention will be described with reference to the drawings.

The heat transfer tube damage detection device 1 in the present embodiment is provided for the boiler system 100. First, an outline of the boiler system 100 will be described with reference to FIGS. 1 to 3.
As shown in FIG. 1, the boiler system 100 includes a fireplace 110, a flue 120, a burner 130, a fireplace wall heat transfer tube 140, a primary superheater 150, a secondary superheater 160, and a final superheater 170. , A reheater 180, an economizer 190, and a heat transfer tube damage detection device 1. Further, although not shown, the boiler system 100 is provided with a soot blower in order to remove dust and the like adhering to the surface of the heat transfer tube. The soot blower injects high-pressure steam onto the surface of the heat transfer tube.

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

The flue 120 is a tubular member formed from the upper part of the fireplace 110 in the horizontal direction and further provided with a downstream end portion toward the lower side in the vertical direction. Combustion gas generated in the fireplace 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 lower wall portion of the fireplace 110 in the circumferential direction of the fireplace 110. Although not shown, a plurality of burners 130 are installed in the vertical direction of the fireplace 110 as well. The burner 130 injects fuel (pulverized coal, liquid fuel, etc.) into the furnace 110 and burns it. Further, the burner 130 supplies heated air together with fuel to the fireplace 110.

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

The primary superheater 150 is provided in a flow path on one side of the downstream end of the flue 120, and includes a plurality of plate-shaped heat transfer plates P composed of a plurality of heat transfer tubes D as shown in FIG. ing. As shown in FIG. 3, the primary superheater 150 is configured by arranging a plurality of heat transfer plates in parallel, and each of them is connected to a tube gathering K. The primary superheater 150 is supplied with steam that has passed through the furnace wall heat transfer tube 140, and the steam is heated by the combustion gas that passes through the flue 120 to bring it into a superheated state. Further, the pipe gathering K is provided on the outside of the wall portion of the flue 120.

The secondary superheater 160 is provided above the fireplace 110, and like the primary superheater 150, a heat transfer plate composed of a plurality of heat transfer tubes is arranged in parallel. The secondary superheater 160 is supplied with superheated steam that has passed through the primary superheater 150, and the superheated steam is heated by 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 pipes on the upstream side and the downstream side, steam is supplied from the pipes on the upstream side, and steam is aggregated by the pipes on the downstream side. Will be done. Further, the pipe fitting of the secondary superheater 160 is provided on the outside of the ceiling wall of the fireplace 110.

The final superheater 170 is provided near the upstream end of the flue 120, and like the primary superheater 150, heat transfer plates composed of a plurality of heat transfer tubes are arranged in parallel. The final superheater 170 is supplied with superheated steam that has passed through the secondary superheater 160, and the superheated steam is further heated by the combustion gas flowing into the flue 120. The 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 pipes on the upstream side and the downstream side, steam is supplied from the pipes on the upstream side, and steam is collected by the pipes on the downstream side. To. Further, the pipe fitting of the final superheater 170 is provided on the outside of the wall portion 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 like 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 reheats the discharged steam with combustion gas. Further, the reheater 180 supplies steam to a reheat turbine (not shown). In the reheater 180, a plurality of heat transfer plates are connected to the pipes on the upstream side and the downstream side, steam is supplied from the pipes on the upstream side, and steam is collected by the pipes on the downstream side. To. Further, the tube gathering of the reheater 180 is provided on the outside of the wall portion of the flue 120.

The economizer 190 is provided on the upper stage of the heat transfer tube 140 on the wall of the fireplace, and is configured by arranging heat transfer plates composed 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 the pipes on the upstream side and the downstream side, steam is supplied from the pipes on the upstream side, and steam is collected by the pipes on the downstream side. To. Further, the economizer 190 is provided on the outside of the wall portion of the flue 120.

Subsequently, the heat transfer tube damage detection device 1 will be described with reference to FIGS. 3 and 4.
The heat transfer tube damage detection device 1 includes a plurality of temperature sensors 2 (measurement means), a temperature information storage unit 3, a temperature information analysis unit 4, and a damage determination unit 5. The heat transfer tube damage detection device 1 is installed as a function of a computer, and is composed of a CPU, a memory, a hard disk, and the like. Further, the temperature information storage unit 3, the temperature information analysis unit 4, and the damage determination unit 5 constitute the 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 such as a primary superheater 150, a secondary superheater 160, a final superheater 170, a reheater 180, and an economizer 190 are arranged. It is provided and measures the temperature (state amount) of the surface of the heat transfer tube. As shown in FIG. 3, the temperature sensors 2 are provided at equal intervals for each of the plurality of heat transfer plates. Further, the temperature sensor 2 is located at a position where the distance from the tube is the same and the influence from the combustion gas is the same for the heat transfer plates connected to the same tube so that the temperature behavior of the fluid is similar. It is provided in. Specifically, the temperature sensor 2 is provided in the secondary superheater 160 between the ceiling wall of the fireplace 110 and the pipe fitting, and the primary superheater 150, the final superheater 170, the reheater 180, and the economizer 190. It is provided between the wall portion of the flue 120 and the pipe fitting. The temperature sensors 2 provided on the heat transfer plates connected to the same tube gathering are provided parallel to each other when viewed from the length direction of the tube gathering.

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

The damage determination unit 5 determines whether or not it is abnormal based on the Mahalanobis distance calculated by the temperature information analysis unit 4. Specifically, the damage determination unit 5 determines that the Mahalanobis distance is abnormal when the calculated Mahalanobis distance is larger than the threshold value based on a predetermined threshold value.

Subsequently, the heat transfer tube damage detection method will be described by taking the case of detection by the primary superheater 150 as an example.
Each temperature sensor 2 constantly measures the temperature of the heat transfer tube D (measurement process). In general, the temperature behaviors detected in adjacent heat transfer panels connected to the same tube group tend to be similar because the effects of the inlet temperature of the heat transfer panels and the combustion gas are similar. Then, when the heat transfer panel is damaged, such similar behavior is lost.
The 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 acquired from a plurality of temperature sensors 2 provided in each heat exchange device to use the temperature data of the adjacent temperature sensors 2. Define the unit space of a data group composed of data. Further, 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, the heat transfer plates P of each heat exchange device have a correlation between the distance between the heat transfer plates P and the temperature behavior. Specifically, the temperature behaviors of adjacent heat transfer plates P tend to be highly similar, and heat transfer plates P provided at positions separated 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 significantly, and as shown by the broken line in FIG. 5, the temperature of the damaged heat transfer plate P is close to. The temperature of the heat transfer plate P changes. Therefore, if a certain heat transfer plate P is damaged or an adjacent heat transfer plate P is damaged, the Mahalanobis distance becomes large.

The damage determination unit 5 determines whether or not the calculated Mahalanobis distance exceeds the threshold value based on the above-mentioned correlation (damage determination step). When the calculated Mahalanobis distance exceeds the threshold value, the damage determination unit 5 determines that damage has occurred in the vicinity of the heat transfer plate P and warns an external device or the like.

According to the heat transfer tube damage detection device 1 according to the present embodiment, it is possible to quickly and accurately detect damage to the heat transfer tubes by comparing the temperature behaviors of the plurality of heat transfer tubes. Therefore, when the heat transfer tube is damaged, the damage can be detected quickly, and the recovery from the heat transfer tube damage can be accelerated. Further, the heat transfer tube damage detecting device 1 can always detect the damage of the heat transfer tube 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 tube alignment, that is, in the length direction of the tube alignment. It is installed at the same position when viewed from the viewpoint. Therefore, the temperature detected by the temperature sensor 2 is similar in the adjacent heat transfer tubes, and it is easy to detect the temperature abnormality of the heat transfer tubes.

Further, according to the heat transfer tube damage detection device 1 according to the present embodiment, the maharabinos 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. , Determine if damage has occurred. Therefore, it is possible to obtain changes in the temperature behavior of each heat transfer tube from the Mahalanobis distance. Therefore, when the heat transfer tube is damaged, the damage can be detected quickly.

Further, the boiler system 100 includes a heat exchange device including a plurality of heat transfer panels arranged in parallel, and the inlet temperature and the combustion gas temperature of the adjacent heat transfer panels are similar to each other. The temperature behavior tends to be similar. Therefore, it is possible to adopt a heat transfer tube damage detection method as in this embodiment.

Although the preferred embodiment of the present invention has been described above with reference to the drawings, the present invention is not limited to the above embodiment. The various shapes and combinations of the constituent members shown in the above-described embodiment are examples, and can be variously changed based on design requirements and the like without departing from the spirit 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 sensor 2 may be provided on all heat transfer plates. This makes it easy to detect in which heat transfer plate the damage is occurring.

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

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

Further, in the above embodiment, the configuration applied to the boiler system 100 has been described, but the present invention is not limited to this. In the heat transfer tube damage detector, since a plurality of heat transfer tubes are provided in parallel, the temperature behavior of the fluid (corresponding to the combustion gas in the present embodiment) flowing outside the tubes in the plurality of heat transfer tubes is similar, and a plurality of heat transfer tube damage detectors are provided. As long as it is a heat exchanger having a similar inlet temperature in the heat transfer tube, the application is not limited.

Further, in the above embodiment, the measuring means measures the temperature of the heat transfer tube, but the present invention is not limited to this, and the measuring means may measure the pressure in the heat transfer tube. In this case, for example, pressure sensors are provided in the pipe gathering K connected to the upstream side and the pipe gathering K connected to the downstream side of the heat transfer tube, and the difference between the pressure on the upstream side and the pressure on the downstream side is calculated. Then, by detecting the change in the differential pressure, damage to the heat transfer tube can be detected.

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 (10)

A heat transfer tube damage detection device that detects damage to the heat transfer tube of a heat exchange device provided with a plurality of heat transfer tubes.
A measuring means that is provided at a position where the behavior of the fluid flowing inside in the plurality of heat transfer tubes is similar and measures the state quantity in the heat transfer tubes, and
A heat transfer tube damage detecting device including a damage determining means for determining damage to the heat transfer tube based on inputs from a plurality of the measuring means. A heat transfer tube damage detection device that detects damage to the heat transfer tube of a heat exchange device provided with a plurality of heat transfer tubes.
In a plurality of heat transfer tubes connected to the same tube group, measuring means provided at equal positions when viewed from the length direction of the tube group and measuring the state amount in the heat transfer tube.
A heat transfer tube damage detecting device including a damage determining means for determining damage to the heat transfer tube based on inputs from a plurality of the measuring means. The heat transfer tube damage detection device according to any one of claims 1 to 2, wherein the state quantity is a temperature. Any one of claims 1 to 3, wherein 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 portion of the boiler. Heat transfer tube damage detector described in. The heat transfer tube damage detecting device according to claim 4, wherein the measuring means is provided between the connecting portion of the outlet pipe. The heat transfer tube damage according to any one of claims 1 to 5, wherein the damage determining means determines that the heat transfer tube is damaged based on the correlation of the measured values from the plurality of measuring means. Detection device. The heat transfer tube damage detecting device according to claim 6, wherein the damage determining means determines that the heat transfer tube is damaged when the difference between the measured values from the plurality of measuring means exceeds a threshold value. The damage determining means is characterized in that damage to the heat transfer tube is determined based on the Mahalanobis distance between the data group formed by accumulating the measured values from the plurality of measuring means and the latest measured value. The heat transfer tube damage detection device according to claim 6. A boiler system including the heat transfer tube damage detection device according to any one of claims 1 to 8. A method for detecting damage to a heat transfer tube of a heat exchanger provided with a plurality of heat transfer tubes.
A measurement process that measures the state quantity of multiple heat transfer tubes,
A method for detecting heat transfer tube damage, which comprises a damage determination step of determining damage to the heat transfer tube based on a plurality of measured values detected in the measurement step.

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