Search

JP-7856236-B2 - Method for monitoring the condition of heat exchanger conduits in a waste heat steam generator and waste heat steam generator

JP7856236B2JP 7856236 B2JP7856236 B2JP 7856236B2JP-7856236-B2

Inventors

  • マリニン，ヴィタリー
  • ステファネスク，アドリアン
  • チェツヒク，デニス

Assignees

  • シーメンス エナジー グローバル ゲゼルシャフト ミット ベシュレンクテル ハフツング ウント コンパニー コマンディートゲゼルシャフト

Dates

Publication Date
20260511
Application Date
20230120
Priority Date
20220412

Claims (8)

  1. A method for monitoring the condition of water or steam conduit (14) in at least one heat exchanger (8, 9, 10) located in the exhaust gas flow of a waste heat steam generator (1), The presence of water vapor in the exhaust gas flow is automatically detected using a sensor (18) that detects a measured value representing the humidity of the exhaust gas flow. When water vapor is detected, an alarm is triggered . The at least one heat exchanger (8, 9, 10) includes a first heat exchanger (8, 9) having a first water or steam conduit (14), and a second heat exchanger (9, 10) located downstream of the first heat exchanger (8, 9) and having a second water or steam conduit (14). The sensor (18) detects measurement values at measurement points distributed across the cross-section of the exhaust gas flow, The measurement points are arranged in a grid pattern, uniformly distributed across the cross-section of the exhaust gas flow. The measurement point is located downstream of the second heat exchanger (9, 10) through which the exhaust gas flow passes. If an alarm occurs, the location of the leak in the first water or steam conduit (14) or the second water or steam conduit (14) is calculated based on the number of sensors (18) that detected an increase in the humidity of the exhaust gas flow. The method is characterized in that the calculated position is output to the operating staff .
  2. The method according to claim 1, characterized in that the sensor (18) is a humidity sensor.
  3. The measured value detected by the sensor (18) is compared with at least one stored limit value. An alarm is triggered if at least one of the detected measurements exceeds the limit value. The method according to feature 2.
  4. The method according to claim 1, characterized in that the location of the leak is calculated based on the number of sensors (18) that detected an increase in the humidity of the exhaust gas flow and the amount of increase in humidity measured by the sensors (18).
  5. A waste heat steam generator (1) having an exhaust gas channel (6), wherein at least one heat exchanger (8, 9, 10) having a conduit (14) for guiding water or steam is arranged , A sensor (18 ) designed to detect the presence of water vapor in the exhaust gas flow being guided through the exhaust gas channel is provided in the exhaust gas channel . The at least one heat exchanger (8, 9, 10) includes a first heat exchanger (8, 9) having a first water or steam conduit (14), and a second heat exchanger (9, 10) located downstream of the first heat exchanger (8, 9) and having a second water or steam conduit (14). The sensor (18) detects measurement values at measurement points distributed across the cross-section of the exhaust gas flow, The measurement points are arranged in a grid pattern, uniformly distributed across the cross-section of the exhaust gas flow. The measurement point is located downstream of the second heat exchanger (9, 10) through which the exhaust gas flow passes. A controller (20) is provided which is data-connected to the sensor (18) and is configured to perform the method according to any one of claims 1 to 4 . A waste heat steam generator (1) characterized by the following:
  6. The waste heat steam generator (1) according to claim 5 , characterized in that the sensor (18) is a humidity sensor.
  7. The waste heat steam generator (1) according to claim 5 is characterized in that a retaining grid (19) for housing the sensors (18) is provided, and the sensors (18) are arranged at regular intervals on the retaining grid (19) across the cross-section of the exhaust gas channel (6).
  8. The waste heat steam generator (1) according to claim 7 , characterized in that the retaining grid (19) is located downstream of the second heat exchangers ( 9, 10).

Description

The present invention relates to a method for monitoring the condition of conduits guiding water or steam to at least one heat exchanger, particularly when viewed downstream, which functions as a superheater, evaporator, and feedwater preheater, located in the exhaust gas flow of a waste heat steam generator. The present invention also relates to a waste heat steam generator having an exhaust gas channel in which at least one more heat exchanger, particularly when viewed downstream, which includes conduits guiding water or steam, is located, which functions as a superheater, evaporator, and feedwater preheater. Waste heat steam generators, often abbreviated as HRSGs ("Heat Recovery Steam Generators"), are known in conventional technology in various configurations. They serve to utilize high-temperature waste gas flows from upstream processes for steam generation and typically feature a waste gas channel with multiple heat exchangers arranged downstream. These heat exchangers usually take the form of superheaters, evaporators, and feedwater preheaters. Leaks in the conduits of heat exchangers carrying water or steam can result in unannounced downtime associated with the failure, which should be avoided. Therefore, it is desirable to detect such leaks as early as possible and provide maintenance staff with sufficient time to locate the leak, determine its extent, plan and carry out repair work. In the past, acoustic detection systems have been established for this purpose, where the noise environment of the waste heat steam generator is monitored using multiple acoustic sensors distributed throughout the waste heat steam generator. Leaks cause changes in ambient noise, which are detected by the sensors. In this case, sensors placed closer to the leak location will detect larger noise changes than sensors placed further away. This allows for the sensor-based localization of leaks. However, a known drawback of acoustic detection systems is that hundreds of sensors must be distributed and wired across the waste heat steam generator, which is extremely cumbersome and costly. Further features and advantages of the present invention will be revealed based on the following description with reference to the accompanying drawings. A schematic side view of a waste heat steam generator according to one embodiment of the present invention is shown.The cross-sectional view along line II-II in Figure 1 is shown.A diagram similar to Figure 1 is shown, schematically illustrating damage to the conduits of multiple heat exchangers within a waste heat steam generator and the resulting steam cloud.Figure 3 shows a cross-sectional view along the line IV-IV.A schematic plan view of the downstream region of a waste heat steam generator according to a further embodiment of the present invention is shown. In the following, the same symbols indicate the same or similar parts or components. Figure 1 shows a waste heat steam generator 1 according to one embodiment of the present invention, which, as is well known, generates superheated steam from feedwater by using the hot waste gas flow from a preceding process, and is used to drive a steam turbine 2. The waste heat steam generator 1 comprises a housing 3 through which a waste gas channel 6, having a waste gas inlet 4 and a waste gas outlet 5, extends and opens to the downstream chimney 7 via a diffuser. Within the waste gas channel 6, three heat exchangers 8, 9, and 10 are sequentially arranged in the direction of waste gas flow. Heat exchanger 8 functions as a superheater, heat exchanger 9 as an evaporator, and heat exchanger 10 as a feedwater preheater. During operation of the waste heat steam generator 1, a high-temperature waste gas flow from a preceding process, such as a high-temperature waste gas flow from a gas turbine process, is introduced into the waste gas channel 6 through the waste gas inlet 4 in the direction of arrow 11. The waste gas flows through the waste gas channel 6 in the direction of arrow 12, enters the chimney 7 through the waste gas outlet 5, flows through the chimney in the direction of arrow 13, and is finally released into the environment. In the process of passing through the waste gas channel 6, the waste gas dissipates heat in a counterflow direction to the feedwater guided through the conduits 14 of the heat exchangers 8, 9, and 10, gradually superheating it. More specifically, the feedwater supplied to the heat exchanger 10 located at the downstream end of the waste gas channel 6 via the feedwater pump 15 is first preheated by the waste gas flow. The preheated feedwater is then supplied to the steam drum 16, which in turn supplies the preheated feedwater to the conduits 14 of the heat exchanger 9. The feedwater is then evaporated in the heat exchanger 9. The generated steam is then supplied to the conduit 14 of the heat exchanger 8, where it is superheated. The superheated steam is finally led to the steam turbine 2, which drives, for example, the ge