JP2008144995A - Plant leakage detecting system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plant leakage detecting system capable of surely detecting a leakage part of a water supply system in safety with a simple constitution in a boiler plant of a heat power plant and the like. <P>SOLUTION: This plant leakage detecting system is composed of a refilled-water volume measuring means 1 for measuring the water volume refilled in the water supply system, temperature sensors 2, 3, 4 disposed on vapor or/and water leakage detection parts of the water supply system, and a leakage part detecting means 6 for detecting the leakage of vapor or/and water on the basis of temperature changes of the leakage detection parts measured by the temperature sensors 2, 3, 4, when the increase of the refilled-water volume is detected. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a plant leak detection system for detecting a leak of water vapor or water in a boiler plant that circulates and uses feed water in a feed water system.

  In a boiler plant such as a thermal power plant, water is heated with a boiler to generate water vapor, and a steam turbine is driven. Then, the exhaust gas is condensed with a condenser and circulated for use as water supply. The water used for circulation in the water supply system is discharged from the system by using a part of the steam for sealing the turbine gland and for removing ash in the boiler. The reduced amount of the water supply is supplied to the water supply system from the makeup water tank, and the amount of makeup water is monitored by a flow meter (see, for example, Patent Document 1).

  The amount of makeup water supplied to the water supply system is maintained at a substantially constant amount during normal operation, but the amount of makeup water increases due to the occurrence of water vapor / water leaks or tube leaks from valve parts such as blow valves and drain valves. . This leakage of water vapor and water not only causes an increase in power generation cost due to an increase in the amount of makeup water, but also has a risk of adversely affecting the equipment around the leakage location. For this reason, conventionally, when the amount of replenishing water increases, the inspector confirms each valve part and piping of the drain system visually or by palpation, and specifies the leak of the valve part or the tube leak.

  Also, a tube leak position detection device is known in which an AE sensor provided in a duct of a boiler detects a sound wave generated by tube leak and identifies a tube leak position (see, for example, Patent Document 2).

JP 2003-139302 A JP 7-248274 A

However, if the inspector confirmed each valve part and piping of the drain system by visual inspection or palpation, because there are many confirmation parts, not only much time and labor are required to identify the leak part, but also the leaked water vapor There was a problem of being accompanied by dangers such as burns.
Further, the tube leak position detecting device described in Patent Document 2 can be used for detecting tube leak in a closed space as in a duct, but other parts of the water supply system may be affected by noise. There was a problem that it would be expensive to install in the entire water supply system.

  Therefore, the present invention provides a plant leak detection system that can detect a leak point of a water supply system safely and reliably with a simple configuration in a boiler plant such as a thermal power plant.

  In order to solve the above problems, the present invention provides a boiler plant that circulates and uses feed water in a feed water system, a make-up water amount measuring means that measures the amount of make-up water replenished to the feed water system, and steam or / and / or the feed water system A plant comprising a temperature sensor provided at a water leak detection location and a leak location detection means for detecting a water vapor or water leak from a temperature change at the leak detection location measured by the temperature sensor when an increase in the amount of makeup water is detected A leak detection system is provided.

  Moreover, this invention provides the plant leak detection system of Claim 1 installed in the discharge side of the blow valve and drain trap which were provided in the steam piping of the said water supply system, and / or warm water piping. It is.

  Further, in the present invention, when the temperature of the leak detection location measured by the temperature sensor exceeds a predetermined reference value, the leak location detection means detects a leak of water vapor or water. The described plant leak detection system is provided.

  In the present invention, a water leak sensor is installed on the discharge side of a blow valve provided in a water pipe of the water supply system, and the leak point detecting means detects water leak with the water leak sensor. The plant leak detection system in any one of thru | or 3 is provided.

  The present invention further comprises storage means for storing the open / close conditions of the blow valve corresponding to the operating state of the boiler plant, and management means for managing the open / close conditions of the blow valve from the operating state of the boiler plant. The plant leak detection system described in any of the above is provided.

  The present invention also provides a plant leak detection system according to claim 5, wherein the leak point detection means removes the blow valve in the open condition from the leak detection target.

  Further, the present invention includes an open / close state detection means for detecting the open / close state of the blow valve, and the leak location detection means compares the open / close condition of the valve corresponding to the operating state with the detected open / close state, and does not match. The plant leak detection system according to claim 5 or 6, wherein a warning is issued.

  Further, in the present invention, when the leak point detection unit detects an increase in the amount of makeup water and does not detect a leak of water vapor or water from the blow valve and the drain trap, it is determined as a boiler tube leak. A plant leak detection system according to any one of claims 1 to 7 is provided.

  Further, according to the present invention, a metal temperature sensor for measuring a metal temperature is provided in the boiler tube, and the leak point detecting means detects a tube leak from a change in the metal temperature. The plant leak detection system described in 1. is provided.

  According to the plant leak detection system of the present invention, in a boiler plant that circulates and uses feed water in a feed water system, a makeup water amount measuring means that measures the amount of makeup water to be supplemented to the feed water system, and steam or / and / or the feed water system A configuration comprising a temperature sensor provided at a water leak detection location and a leak location detection means for detecting a water vapor or water leak from a temperature change at the leak detection location measured by the temperature sensor when an increase in the amount of makeup water is detected It is possible to detect the leakage of water vapor or water from the water supply system by increasing the amount of makeup water, and the leak location detects the temperature change because the temperature of the pipe or the piping changes due to the leakage of water vapor or water. The leak location can be identified by the location where the temperature sensor is installed. In addition, since the leak detection is performed when the makeup water volume measuring means detects an increase in the makeup water volume, it is possible to perform highly reliable leak location detection by eliminating temperature changes due to factors other than leak such as load increase / decrease. There is an effect that can be done.

  Moreover, this invention has a structure of the blow valve provided in the discharge | emission side of the blow valve provided in the steam piping of the said water supply system, and / or warm water piping, and a drain trap. Or when water vapor | steam or warm water leaks from a drain trap, since a temperature sensor detects a raise of temperature, there exists an effect which can detect a leak location reliably.

  Further, in the present invention, when the temperature of the leak detection location measured by the temperature sensor exceeds a predetermined reference value, the leak location detection means detects a leak of water vapor or water. With the described configuration, there is an effect that a leak point can be easily detected by comparing a predetermined reference value with a temperature measured by a temperature sensor.

  In the present invention, a water leak sensor is installed on the discharge side of a blow valve provided in a water pipe of the water supply system, and the leak point detecting means detects water leak with the water leak sensor. By having the configuration described in any one of 3 to 3, there is an effect that it is possible to reliably detect a water leak with a small temperature change at the leak location.

  The present invention further comprises storage means for storing the open / close conditions of the blow valve corresponding to the operating state of the boiler plant, and management means for managing the open / close conditions of the blow valve from the operating state of the boiler plant. By having the configuration described in any of the above, it is possible to grasp the open / closed state of each blow valve of the boiler plant, and to identify the blow valve that is open and the leaking blow valve .

  Further, the present invention has the configuration according to claim 5, wherein the leak location detecting means excludes the blow valve in the open condition from the leak detection target, so that the blow valve in the open state is erroneously detected as the leak location. There is an effect that can be prevented.

  Further, the present invention includes an open / close state detection means for detecting the open / close state of the blow valve, and the leak location detection means compares the open / close condition of the valve corresponding to the operating state with the detected open / close state, and does not match. By having the configuration according to claim 5 or 6 which issues a warning, there is an effect that it is possible to detect a malfunction of the blow valve.

  Further, in the present invention, when the leak point detection unit detects an increase in the amount of makeup water and does not detect a leak of water vapor or water from the blow valve and the drain trap, it is determined as a boiler tube leak. By having the configuration according to any one of claims 1 to 7, it is possible to easily detect the occurrence of tube leak that is difficult to detect from the state outside the boiler.

  Further, according to the present invention, a metal temperature sensor for measuring a metal temperature is provided in the boiler tube, and the leak point detecting means detects a tube leak from a change in the metal temperature. By having the configuration described in the above, there is an effect that the tube leak portion can be specified safely and reliably even during operation of the boiler.

Embodiments of the present invention will be described based on examples shown in the drawings.
A plant leak detection system according to the present invention includes a replenishment water amount measuring means 1 for measuring a replenishment water amount replenished to the water supply system, and steam or / and water of the water supply system in a boiler plant that circulates and uses the water supply in the water supply system. Detects water vapor or water leak from temperature sensors 2, 3 and 4 provided at the leak detection location and temperature changes at the leak detection location measured by the temperature sensors 2, 3 and 4 when an increase in the amount of makeup water is detected The leak location detecting means 6 is configured.

  FIG. 1 is a block diagram showing an embodiment of a plant leak detection system according to the present invention. In the embodiment shown in FIG. 1, the boiler plant is a thermal power plant, the boiler 10 heats the feed water in the boiler tube 11 to generate steam, supplies the steam to the turbine 20 through the steam pipe 12, and the turbine It is comprised so that 20 may be rotated and it may generate electric power. A condenser 21 is provided at the lower end of the turbine 20. The steam used for power generation by rotating the turbine 20 is cooled and returned to water, and passes through the water pipe 13 and the boiler tube 11 by the feed pump 14. The water supply is recirculated and used in the water supply systems 11, 12, and 13.

  In FIG. 1, reference numeral 22 denotes a makeup water tank that stores makeup water. The make-up water tank 22 compensates for the decrease in water supply by discharging a part of the water vapor outside the system for sealing the turbine gland and for removing ash in the boiler, and the like. In order to maintain the amount of water constant, makeup water is replenished to the condenser 21. Further, a make-up water amount measuring means 1 comprising a flow meter is provided between the make-up water tank 22 and the condenser 21 so that the amount of make-up water to be supplied to the condenser 21 can be measured. .

  The leak location detection means 6 monitors the amount of makeup water measured by the makeup water amount measurement means 1 and detects an increase in the amount of makeup water when water vapor or water leaks from valve parts such as the blow valves 15 and 16 and the drain valve 17. Alternatively, it is determined that a tube leak has occurred and the leak location is detected. Moreover, the leak location detection means 6 is provided with a discharge amount management means for managing the discharge amount of the feed water from the opening degree of the discharge valve that discharges water vapor and the like out of the system, and compares the discharge amount of the feed water with the make-up water amount. It is also possible to configure so that the occurrence of tube leak or the like can be determined when the value increases.

  As shown in FIGS. 1 to 3, the temperature sensors 2 and 3 are thermocouples and are installed on the discharge side of the blow valve 15 and the drain trap 17 provided in the steam pipe 12. In the illustrated embodiment, the temperature sensors 2 and 3 are inserted from the upper side to the lower side of the steam discharge pipe 18, and the temperature detection unit is provided below the center of the steam discharge pipe 18, so that the blow valve 15 or the drain is provided. Water vapor leaking from the trap 17 can be directly detected. Further, the temperature sensors 2 and 3 reduce the influence caused by the temperature change of the water vapor in the steam pipe 12 and can detect a small amount of leak from the blow valve 15 or the drain trap 17 by 20 to 30 cm. It is preferable to be installed at the position. The temperature sensors 2 and 3 may be various temperature sensors other than thermocouples, and may be installed around the steam discharge pipe 18.

  In the illustrated embodiment, the leak point detection means 6 detects the leak of water vapor when the temperature of the leak detection point measured by the temperature sensors 2 and 3 exceeds a predetermined reference value for each valve. is there. Further, the leak location detecting means 6 can be determined by changing the reference value for each season. Of course, the leak location detection means 6 can detect a water vapor leak from the temperature rise amount at the leak detection location measured by the temperature sensors 2 and 3 without setting a reference value.

In FIGS. 1 and 4, reference numeral 5 denotes a water leakage sensor, which is installed in a water discharge pipe 19 on the discharge side of the blow valve 16 provided in the water pipe 13. The leak location detection means 6 is configured such that the leak sensor 6 can directly detect a water leak from the blow valve 16.
In addition, temperature sensors 2 and 3 are provided in the blow valve 16 provided in the hot water pipe near the boiler 10 among the water pipes 13 and the water supply is warmed by preheating. Can also be detected.

  As shown in FIG. 1, the boiler tube 11 is provided with metal temperature sensors 4 at predetermined intervals so that the metal temperature of the boiler tube 11 can be measured. The leak location detection means 6 compares the metal temperatures measured by the adjacent metal temperature sensors 4 and 4 and when the metal temperature located behind increases, the tube leak between the metal temperature sensors 4 and 4 is detected. It is configured to detect occurrence.

  In the illustrated embodiment, when the increase in the amount of replenishment water is detected by the replenishment water amount measurement unit 1, the leak location detection means 6 first searches for leak locations in the blow valves 15 and 16 and the drain trap 17. The leak location detection means 6 is configured to display a leak location valve and issue a warning when the temperature sensor 2, 3 or the water leak sensor 6 detects a leak in the blow valves 15, 16 or the drain trap 17. It is.

  Further, the leak point detection means 6 is a tube leak in which water vapor leaks from the boiler tube 11 when the temperature sensor 2 or 3 or the water leak sensor 6 does not detect the leak of the blow valves 15 and 16 or the drain trap 17. Judging that there is. When it is determined that the leak is a tube leak, the leak location detection means 6 compares the metal temperature measured by the adjacent metal temperature sensors 4 and 4 to identify the leak location, displays the leak location of the boiler tube 11 and gives a warning. It is configured to be able to emit.

  The plant leak detection system according to the present invention manages the opening and closing conditions of the blow valves 15 and 16 corresponding to the operating state of the boiler plant, and manages the opening and closing conditions of the blow valves 15 and 16 from the operating state of the boiler plant. It is preferable to have a management means. When detecting an increase in the amount of makeup water, the leak location detection means 6 removes the open condition blow valves 15 and 16 from the leak detection target, and searches for leak locations in the close condition blow valves 15 and 16 and the drain trap 17. It is.

  In the plant leak detection system according to the present invention, the leak location detection means 6 may be configured to include an open / close state detection means for detecting the open / close state of the blow valves 15 and 16. The open / closed state detecting means detects the closed state of the valve when the temperature of the detection point measured by the temperature sensor 2 is equal to or lower than a predetermined reference value for each valve. The state is detected. The open / closed state detection means detects the open state of the valve when the water leakage sensor 6 detects water flow through the water discharge pipe 19 and detects the closed state of the valve when water flow through the water discharge pipe 19 is not detected. I have to do it.

  The open / close state detection means compares the valve open / close conditions corresponding to the operation state of the boiler plant described above with the detected open / close state of the valve, and can issue a warning and detect a malfunction of the valve when they do not match. It is constituted as follows.

The block diagram which shows one Example of the plant leak detection system which concerns on this invention. Sectional drawing which shows the principal part of the one Example. Sectional drawing which shows the principal part of the one Example. Sectional drawing which shows the principal part of the one Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Supply water amount measurement means 2, 3 Temperature sensor 4 Metal temperature sensor 5 Water leak sensor 6 Leak location detection means 10 Boiler 11 Boiler tube 12 Steam piping 13 Water piping 14 Water supply pumps 15, 16 Blow valve 17 Drain trap 18 Steam discharge pipe 19 Water Discharge pipe 20 Turbine 21 Condenser 22 Makeup water tank

Claims (9)

  In a boiler plant that circulates and uses feed water in the feed water system, a make-up water amount measuring means that measures the amount of make-up water replenished to the feed water system, a temperature sensor provided at a water vapor or / and water leak detection point of the feed water system, A plant leak detection system comprising leak point detection means for detecting a leak of water vapor or water from a temperature change of a leak detection point measured by the temperature sensor when an increase in the amount of makeup water is detected.   The plant leak detection system according to claim 1, wherein the temperature sensor is installed on a discharge side of a blow valve and a drain trap provided in a steam pipe or / and a hot water pipe of the water supply system.   The plant leak detection system according to claim 2, wherein when the temperature of the leak detection point measured by the temperature sensor exceeds a predetermined reference value, the leak point detection means detects a leak of water vapor or water. .   The water leakage sensor is installed in the discharge side of the blow valve provided in the water piping of the said water supply system, The said leak location detection means detects the leak of water with this water leakage sensor. The described plant leak detection system.   The storage means which memorize | stores the open / close condition of the blow valve corresponding to the operation state of a boiler plant, The management means which manages the open / close condition of a blow valve from the operation state of a boiler plant, It provided in any one of Claim 1 thru | or 4 Plant leak detection system.   The plant leak detection system according to claim 5, wherein the leak point detection means removes the blow valve under the open condition from the leak detection target.   The leak location detection means includes an open / close state detection means for detecting the open / close state of the blow valve, and compares the open / close condition of the valve corresponding to the operating state with the detected open / close state, and issues a warning when they do not match. The plant leak detection system according to claim 5 or 6.   The leak point detection means detects an increase in the amount of makeup water, and determines no boiler tube leak when no leak of water vapor or water is detected from the blow valve and drain trap. The plant leak detection system in any one. The plant leak detection according to any one of claims 1 to 8, wherein a metal temperature sensor for measuring a metal temperature is provided in the boiler tube, and the leak point detection means detects a tube leak from a change in the metal temperature. system.

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