A high-pressure heater pipe cleaning connection structure and a method for installing the same

Abstract

The application discloses a high-pressure heater pipeline cleaning connecting structure and a mounting method thereof. The passage of the manhole door is in an elliptical shape, a connecting pipe is arranged in the passage, inner and outer flanges are arranged on the two sides of the passage respectively, the outer flange is opposite to the inner flange, and the inner and outer flanges on the two sides are clamped and fixed on the two sides of the passage by means of tension bolts. The pipeline cleaning connecting structure does not need to cut the manhole door of the high-pressure heater, is quickly connected with a cleaning pipeline, has good airtightness, and is high in reliability.

Description

Technical Field

[0001] This invention relates to a cleaning pipe connection structure and installation method for internal cleaning of a high-pressure heater. Background Technology

[0002] A high-pressure heater is a device that uses a portion of the extracted steam from a steam turbine to heat feedwater. This device consists of two main parts: a shell and a piping system. A steam condensation section is located in the upper part of the shell's inner cavity, and a condensate cooling section is located in the lower part. Feedwater inlet and outlet are located at the top of the inlet and outlet pipes. When superheated steam enters the shell through the inlet, it heats the feedwater in the upper main spiral tube. After the steam condenses into water, the condensed hot water can then heat a portion of the feedwater in the lower condensate cooling spiral tube. The utilized condensate flows out of the boiler through the condensate outlet. However, due to the high operating parameters of modern power plants, oxide scale particles easily form inside the boiler, causing oxide particles to be mixed in with the steam and feedwater. Ferric hydroxide introduced from the steam-water system decomposes, forming adhering magnetic iron oxide, which easily adheres to the inner wall of the high-pressure heater shell and the surface of the heating tubes. Over time, the large amount of magnetic iron oxide adhering to the surface of the heating tubes affects the heating effect of the high-pressure heater and hinders its normal operation. Magnetic iron oxide is difficult to remove with normal cleaning solutions and requires a strong oxidizing cleaning solution for effective removal. However, the strong oxidizing properties of cleaning solutions mean that accidental leaks can harm people and damage surrounding vegetation. Furthermore, cleaning iron oxide with such solutions produces toxic gases that can cause irreversible damage if inhaled. Therefore, conventional chemical cleaning methods involve cutting open the manhole of the high-pressure heater and welding a cleaning pipe to the opening. Simultaneously, the weld between the cleaning pipe and the manhole must be sealed tightly. After cleaning, the weld is cut back, and the manhole is resealed. This method effectively cleans the interior of the high-pressure heater while maintaining a sealed environment. However, to ensure a proper connection to the cleaning pipe, the manhole needs to be cut open, a temporary pipe welded to the opening, and the weld cut again before the manhole is restored. This method of cleaning high-pressure heaters takes a particularly long time. The power supply system is crucial to the normal operation of society. In large-scale power transmission and transformation, the heating process of the high-pressure heater boiler is very important. Once the heating process stops working, the subsequent power generation process will also be forced to stop, the entire power plant will be paralyzed, and the normal operation of the power supply system will be affected. Summary of the Invention

[0003] The purpose of this invention is to provide a high-pressure heater cleaning pipeline connection structure and its installation method that allows for quick connection to cleaning pipelines, provides good sealing, and reduces cleaning construction time.

[0004] A high-pressure heater pipeline cleaning connection structure is disclosed, wherein the manhole of the high-pressure heater has an elliptical channel, with inner and outer flanges respectively installed on both sides of the channel. The inner flange is a threaded flange with an elliptical outer contour. The minor axis dimension is between the minor and major axes of the elliptical channel, while the major axis is larger than the major axis of the channel. The outer flange is opposite to the inner flange and covers the outer opening of the channel. A sealing ring is installed between the outer flange and the outer wall of the manhole. A connecting pipe is located inside the channel, with one end fixed to the inner flange by a threaded connection, and the other end passing through the outer flange. Two or more tension bolts are installed in the channel outside the connecting pipe. The inner and outer flanges are respectively provided with corresponding threaded holes and through holes. The tension bolts pass through the through holes of the outer flange and screw into the threaded holes of the inner flange, tightening and clamping the inner and outer flanges on both sides of the channel. An annular step is provided on the outer flange at the hole through which the connecting pipe passes. A sealing gasket is installed in the annular step. A pressure nut is screwed onto the outside of the connecting pipe and presses the sealing gasket.

[0005] An installation method for a high-pressure heater pipeline cleaning connection structure includes the following steps:

[0006] A. Remove the manhole cover of the high-pressure heater;

[0007] B. Place the inner flange flat with its short axis aligned with the long axis of the passage, and extend it through the manhole passage into the high-pressure heater;

[0008] C. Rotate the inner flange so that it is upright and its edge abuts against the wall of the high-pressure heater inside the channel;

[0009] D. Screw the tension bolt into the threaded hole of the inner flange, with its head protruding from the outside of the passage. Pull the head of the tension bolt to temporarily suspend the inner flange inside the passage.

[0010] E. Insert the connecting pipe into the manhole passage and screw it onto the thread of the inner flange, leaving the other end suspended; then loosen the tension bolt from the inner flange and pull it out.

[0011] F. Insert the outer flange into the outer end of the connecting pipe; install the sealing gasket in the annular step where the connecting pipe exits; screw the clamping nut into the outer end of the connecting pipe to tighten the sealing gasket;

[0012] G. Use the tension bolts again, pass them through the outer flange from the outside of the passage and screw them onto the inner flange, pressing the inner and outer flanges tightly against the inside and outside of the manhole from both sides.

[0013] This invention discloses a high-pressure heater pipeline cleaning connection structure. The manhole cover of the high-pressure heater is removed. The inner flange has an elliptical outer contour, with its minor axis between the minor and major axes of the elliptical channel, and its major axis larger than the channel's major axis. The inner flange is placed horizontally, its minor axis aligned with the channel's major axis, and extends through the manhole into the high-pressure heater. The inner flange is rotated until it is upright, with its edge abutting against the high-pressure heater wall inside the channel. A tension bolt is screwed into the threaded hole of the inner flange, its head extending from the outside of the channel. The tension bolt head is pulled, temporarily suspending the inner flange inside the channel. Insert the connecting pipe into the manhole passage and screw it onto the threads of the inner flange, leaving the other end suspended. Then, loosen the tension bolt from the inner flange and pull it out. Slide the outer flange onto the outer end of the connecting pipe, and install the sealing gasket inside the annular step where the connecting pipe exits. Screw the compression nut onto the outer end of the connecting pipe to tighten the sealing gasket. Use the tension bolt again, passing it through the outer flange from the outside of the passage and screwing it onto the inner flange. Press the inner and outer flanges tightly against the inner and outer sides of the manhole. Weld a cleaning pipe to the outer connecting pipe. The cleaning pipe injects cleaning fluid into the high-pressure heater through the connecting pipe, achieving chemical cleaning of the high-pressure heater's interior. The outer flange covers the outer opening of the passage, and a sealing ring is installed between it and the outer wall of the manhole. The outer flange effectively prevents the cleaning fluid from overflowing, and the sealing ring ensures the airtightness of the connection structure, further preventing the cleaning fluid from overflowing. The sealing ring also has an elastic effect, allowing the outer flange to be better fixed to the manhole side wall. The connecting pipe is located inside the channel, with one end fixed to the inner flange via a threaded connection, and the other end protruding from the outer flange. A tension bolt passes through the through-hole of the outer flange and screws into the threaded hole of the inner flange, tightening and clamping the inner and outer flanges to both sides of the channel. When cleaning the inside of the high-pressure heater, the cleaning pipe is directly welded to the connecting pipe, achieving a sealed connection between the cleaning pipe and the manhole door. This connection is quick, provides excellent sealing, and effectively reduces the amount of work required for cutting and restoring the manhole door. A pressure nut is screwed onto the outside of the connecting pipe and presses down on the sealing gasket. The pressure nut against the sealing gasket effectively prevents the injected cleaning fluid from overflowing from the gap in the outer flange, ensuring the airtightness of the connection structure and effectively increasing the safety and reliability of construction. This cleaning pipe connection structure allows for direct welding of the cleaning pipe to the connecting pipe when cleaning the inside of the high-pressure heater, eliminating the need to cut the manhole door of the high-pressure heater. It provides a quick and airtight connection, eliminates concerns about cleaning fluid leakage, and offers high reliability. Attached Figure Description

[0014] Figure 1 This is a cross-sectional view of a high-pressure heater pipeline cleaning connection structure.

[0015] Figure 2 This is a perspective view of a connection device for a high-pressure heater pipeline cleaning connection structure.

[0016] Figure 3 This is a cross-sectional view of a high-pressure heater pipeline cleaning connection structure. Detailed Implementation

[0017] like Figures 1-3 As shown, a high-pressure heater pipeline cleaning connection structure is provided. The passage 7 of the manhole 10 of the high-pressure heater 11 is elliptical. An inner flange 3 is provided on the inner side of the passage, and an outer flange 2 is provided on the outer side of the passage. The inner flange is a threaded flange, and its outer contour is elliptical. The minor axis dimension is between the minor axis and the major axis dimension of the elliptical passage, while the major axis is larger than the major axis dimension of the passage. The outer contour of the inner flange can also be rectangular, with the width dimension between the minor axis and the major axis dimension of the elliptical passage, and the length being larger than the major axis dimension of the passage. The outer flange is opposite to the inner flange and covers the outer opening of the passage. It is adjacent to the outer wall of the manhole. A sealing ring 9 is set between them; the connecting pipe 1 is located in the channel, one end of which is fixed to the inner flange by threaded connection, and the other end passes through the outer flange and is welded to the cleaning pipe 12. Two or more tension bolts 4 are set in the channel outside the connecting pipe. The inner and outer flanges are respectively provided with corresponding threaded holes and through holes. The tension bolts pass through the through holes of the outer flange and are screwed into the threaded holes of the inner flange to tighten and clamp the inner and outer flanges on both sides of the channel; the outer flange is provided with an annular step 8 at the hole through which the connecting pipe passes. A sealing gasket 5 is installed in the annular step. The compression nut 6 is screwed onto the outside of the connecting pipe and compresses the sealing gasket. During installation and use, remove the manhole cover of the high-pressure heater. The inner flange has an elliptical outer contour, with its minor axis between the minor and major axes of the elliptical channel, and its major axis larger than the major axis of the channel. Place the inner flange flat, aligning its minor axis with the major axis of the channel, and insert it into the high-pressure heater through the manhole channel. Rotate the inner flange until it is upright, with its edge abutting against the wall of the high-pressure heater inside the channel. Screw the tension bolt into the threaded hole of the inner flange, with its head protruding from the outside of the channel. Pull the tension bolt head to temporarily suspend the inner flange inside the channel. Insert the connecting pipe into... Inside the manhole passage, screw the inner flange onto its thread, leaving the other end suspended. Then, loosen and pull the tension bolt from the inner flange, insert the outer flange onto the outer end of the connecting pipe, install the sealing gasket within the annular step where the connecting pipe exits, and screw the compression nut onto the outer end of the connecting pipe to tighten the gasket. Again, use the tension bolt to pass through the outer flange from the outside of the passage and screw it onto the inner flange, pressing the inner and outer flanges tightly against the manhole from both sides. A cleaning pipe is welded to the outer connecting pipe, which injects cleaning fluid into the high-pressure heater, achieving chemical cleaning of the heater's interior. This cleaning pipe connection structure allows for direct welding of the cleaning pipe to the connecting pipe during cleaning of the high-pressure heater's interior, eliminating the need to cut the manhole of the high-pressure heater. It provides quick connection, excellent sealing, eliminates concerns about cleaning fluid leakage, and offers high reliability.

[0018] To prevent cleaning fluid from flowing back through the manhole gap during cleaning of the high-pressure heater's interior, a space is provided between the inner flange and the inner wall of the manhole, as shown in the image. Figure 1 The sealing ring shown makes the connection between the inner flange and the inner wall of the manhole more secure, thereby improving the airtightness of the connection structure.

[0019] like Figure 1 As shown, in order to further improve the airtightness of the connection structure, the clamping nut extends into the annular step and clamps the sealing gasket. The clamping nut extending into the annular step can prevent the clamping nut from coming off, thereby strengthening the firmness and further improving the airtightness of the connection structure.

Claims

1. A connection structure for cleaning pipelines of a high-pressure heater, characterized in that, The manhole of the high-pressure heater has an elliptical channel (7). The inner and outer flanges are respectively provided on both sides of the channel. The inner flange (3) is a threaded flange with an elliptical outer contour. The minor axis dimension is between the minor axis and the major axis dimension of the elliptical channel, and the major axis is larger than the major axis of the channel. The outer flange (2) is opposite to the inner flange and covers the outer opening of the channel. A sealing ring (9) is provided between the outer flange and the outer wall of the manhole. The connecting pipe (1) is located in the channel. One end of the pipe is fixed to the inner flange by thread, and the other end passes through the outer flange. Two or more tension bolts are provided in the channel outside the connecting pipe. The inner and outer flanges are respectively provided with corresponding threaded holes and through holes. The tension bolt (4) passes through the through hole of the outer flange and screws into the threaded hole of the inner flange to tighten and clamp the inner and outer flanges on both sides of the channel. The outer flange has an annular step (8) at the hole through which the connecting pipe passes. A sealing gasket (5) is installed in the annular step. The compression nut (6) is screwed onto the outside of the connecting pipe and the sealing gasket is compressed.

2. The high-pressure heater pipeline cleaning connection structure according to claim 1, characterized in that, A sealing ring is installed between the inner flange and the inner wall of the manhole.

3. The high-pressure heater pipeline cleaning connection structure according to claim 1, characterized in that, The clamping nut extends into the annular step and clamps the sealing gasket.

4. The high-pressure heater pipeline cleaning connection structure according to claim 1, characterized in that, The inner flange has a rectangular outer contour, with its width between the minor and major axes of the elliptical channel, and its length greater than the major axis of the channel.

5. The installation method of the high-pressure heater pipeline cleaning connection structure according to claim 1, characterized in that, Includes the following steps: A. Remove the manhole cover of the high-pressure heater; B. Place the inner flange flat with its short axis aligned with the long axis of the passage, and extend it through the manhole passage into the high-pressure heater; C. Rotate the inner flange so that it is upright and its edge abuts against the wall of the high-pressure heater inside the channel; D. Screw the tension bolt into the threaded hole of the inner flange, with its head protruding from the outside of the passage. Pull the head of the tension bolt to temporarily suspend the inner flange inside the passage. E. Insert the connecting pipe into the manhole passage and screw it onto the thread of the inner flange, leaving the other end suspended; then loosen the tension bolt from the inner flange and pull it out. F. Insert the outer flange onto the outer end of the connecting pipe; install the sealing gasket inside the annular step where the connecting pipe exits; Screw the clamping nut onto the outside of the connecting pipe to tighten the sealing gasket; G. Use the tension bolts again, pass them through the outer flange from the outside of the passage and screw them onto the inner flange, pressing the inner and outer flanges tightly against the inside and outside of the manhole from both sides.

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