CN-121993781-A - Cavitation-proof vertical steam generator

CN121993781ACN 121993781 ACN121993781 ACN 121993781ACN-121993781-A

Abstract

The invention relates to an anti-cavitation vertical steam generator which comprises an upper pipe box, a lower pipe box, an upper pipe plate, a lower pipe plate, a shell side barrel, a heat exchange pipe and an anti-cavitation structure, wherein a barrel inlet communicated with a cold flow cavity is formed on the lower side of the shell side barrel, the barrel inlet is located above the lower pipe plate, a barrel outlet communicated with the cold flow cavity is formed on the upper side of the shell side barrel, the barrel outlet is located below the upper pipe plate, the heat exchange pipe is used for containing high-temperature medium and is arranged in the cold flow cavity in an extending mode along the up-down direction, the anti-cavitation structure comprises a defoaming pipe and an anti-cavitation plate, the anti-cavitation plate is arranged in the cold flow cavity and is located between the upper pipe plate and the barrel outlet in the up-down direction, the defoaming pipe is used for containing a second cooling medium, the defoaming pipe penetrates through the anti-cavitation plate, and the outlet protrudes out of the upper surface of the anti-cavitation plate. The cavitation prevention plate can prevent the first cooling medium from directly impacting the upper tube plate, and the second cooling medium in the defoaming tube can reduce the medium temperature at the outlet of the cylinder body, thereby reducing the formation of bubbles and cavitation.

Inventors

GUO XUEHUA
LI ZHEN
CHEN ZHIMIN
PENG YU
WANG JINGUANG
YAN DONGSHENG
LIU LIANGHAI

Assignees

中国石油化工股份有限公司
中国石化工程建设有限公司
中国石油化工股份有限公司镇海炼化分公司
中石化炼化工程（集团）股份有限公司洛阳技术研发中心
中国石化上海石油化工股份有限公司

Dates

Publication Date: 20260508
Application Date: 20241106

Claims (10)

1. The cavitation-resistant vertical steam generator is characterized by comprising an upper pipe box, a lower pipe box, an upper pipe plate, a lower pipe plate, a shell side cylinder, a heat exchange pipe and a cavitation-resistant structure; The shell side cylinder body extends in the up-down direction, the upper pipe box is covered and connected with the upper end of the shell side cylinder body, and the lower pipe box is covered and connected with the lower end of the shell side cylinder body; the upper tube plate is arranged between the upper tube box and the shell side cylinder in a horizontal direction in an extending manner, and the lower tube plate is arranged between the lower tube box and the shell side cylinder in a horizontal direction in an extending manner, wherein the upper tube plate, the lower tube plate and the shell side cylinder define a cold flow cavity for containing a first cooling medium; The lower side of the shell-side cylinder is provided with a cylinder inlet communicated with the cold flow cavity, the cylinder inlet is positioned above the lower tube plate, the upper side of the shell-side cylinder is provided with a cylinder outlet communicated with the cold flow cavity, and the cylinder outlet is positioned below the upper tube plate; the heat exchange tube is used for accommodating a high-temperature medium and is arranged in the cold flow cavity in an extending manner along the up-down direction; The anti-cavitation structure comprises a defoaming pipe and an anti-cavitation plate, the anti-cavitation plate is arranged in the cold flow cavity and located between the upper pipe plate and the cylinder body outlet in the up-down direction, the defoaming pipe is used for containing a second cooling medium, and the anti-cavitation plate is arranged in the defoaming pipe in a penetrating mode, and the outlet of the anti-cavitation plate protrudes out of the upper surface of the anti-cavitation plate.
2. The anti-cavitation vertical steam generator of claim 1, wherein the de-bubbling pipe comprises a first pipe section extending horizontally out of the down pipe box, a connecting elbow, a second pipe section, and a connecting flange, the first pipe section comprising a first end located within the down pipe box and a second end located outside of the down pipe box, the connecting flange being connected to the second end of the first pipe section; The connecting bent pipe is arranged in the lower pipe box, the first end of the connecting bent pipe is connected with the first end of the first pipe section, the second pipe section extends along the upper and lower direction and sequentially penetrates through the lower pipe plate and the cavitation prevention plate from bottom to top, the second end of the connecting bent pipe is connected with the first end of the second pipe section, and the second end of the second pipe section protrudes out of the upper surface of the cavitation prevention plate.
3. The vertical cavitation-preventing steam generator according to claim 2, wherein the defoaming pipe further comprises a pipe cap connected to the second end of the second pipe section, and wherein a plurality of water outlet holes are formed in the side wall of the second end of the second pipe section and above the cavitation-preventing plate.
4. The cavitation-preventing vertical steam generator according to claim 1, wherein the cavitation-preventing structure further comprises a plurality of support plates, a guide cylinder and an annular plate, the annular plate is arranged in the cold flow cavity in a horizontal direction in an extending manner and is connected with the inner wall of the shell side cylinder, the guide cylinder extends in an up-down direction, the lower end of the guide cylinder is connected with the annular plate, the plurality of support plates extend in the up-down direction and are arranged at the upper part of the guide cylinder in a circumferentially two-by-two interval manner, and the cavitation-preventing plate is connected with the upper ends of the plurality of support plates.
5. The cavitation-resistant vertical steam generator according to claim 4, wherein the guide cylinder comprises a plurality of first areas and a plurality of second areas, the first areas and the second areas are alternately arranged in sequence, and the first areas are arranged in one-to-one correspondence with the cylinder outlets; Each second area is provided with a plurality of vent holes, each vent hole comprises a plurality of first vent hole groups which are arranged at intervals in the up-down direction, each first vent hole group comprises a plurality of first vent holes which are arranged at intervals in the circumferential direction of the guide cylinder, and the apertures of the first vent holes are sequentially increased in the up-down direction.
6. The anti-cavitation vertical steam generator of claim 4 wherein the upper end of the guide shell is configured in a saw tooth configuration.
7. The anti-cavitation vertical steam generator of claim 4, further comprising a plurality of baffles, wherein a plurality of baffles are disposed in the cold flow chamber and between the annular plate and the lower tube plate, and wherein two adjacent baffles are disposed at a vertical interval.
8. The anti-cavitation vertical steam generator of any of claims 1-4 further comprising a shell side inlet tube in communication with the cylinder inlet and located outside the cold flow chamber and a shell side outlet tube in communication with the cylinder outlet and located outside the cold flow chamber.
9. The cavitation-resistant vertical steam generator of claim 2 wherein the axis of the second tube section and the axis of the shell side cylinder are coincident with each other.
10. The anti-cavitation vertical steam generator of claim 2, wherein the connection flange is welded to the first tube segment, a first end of the first tube segment is welded to a first end of the connection elbow, and a first end of the second tube segment is welded to a second end of the connection elbow.

Description

Cavitation-proof vertical steam generator Technical Field The present disclosure relates to the technical field of steam generators, and in particular, to an anti-cavitation vertical steam generator. Background The steam generator, called steam boiler, is an important component of the steam power plant, the high temperature process gas of the steam generator flows in the pipe, the water flows in the shell outside the pipe, the heat is transferred to the water outside the pipe through the pipe wall, and the structure is similar to a shell-and-tube heat exchanger. Because of the relatively high operating temperatures, steam generators typically employ thin tube sheet structures for effective thermal expansion, and during long-term operation of the steam generator, the tube bundle portion of the shell side near the outlet end, including the tube sheets and heat exchange tubes, is often found to exhibit severe erosion. The high-temperature medium can quickly surge to the area where the bubbles are located under the action of pressure difference when the bubbles are gathered on the surfaces of the tube plate and the heat exchange tube, so that the tube plate and the heat exchange tube surface are eroded, and the reliability of a welded joint can be even affected if the heat exchange tube joint adopts deep hole butt welding. For a long time, researchers and designers are very important to consider corrosion resistance of a tube plate on the side of a heat exchanger tube box and protection of a welded joint of a heat exchange tube, and in order to improve the reliability of the welded joint of the heat exchange tube, a plurality of feasible measures are proposed. However, the impact corrosion of the shell side tube plate under some special working conditions, such as the case that the shell side medium is a two-phase flow, is ignored, and through the research and study of a plurality of projects, the corrosion phenomenon not only occurs on the surface of the tube plate, but also occurs on the surface of the heat exchange tube, and some heat exchangers have leakage accidents. For the above reasons, improvements in the shell side structure of steam generators are necessary. Disclosure of Invention The purpose of the present disclosure is to provide a cavitation-preventing vertical steam generator to solve the technical problems existing in the related art. In order to achieve the above object, the present disclosure provides an anti-cavitation vertical steam generator, comprising an upper tube box, a lower tube box, an upper tube plate, a lower tube plate, a shell side cylinder, a heat exchange tube and an anti-cavitation structure; The shell side cylinder body extends in the up-down direction, the upper pipe box is covered and connected with the upper end of the shell side cylinder body, and the lower pipe box is covered and connected with the lower end of the shell side cylinder body; the upper tube plate is arranged between the upper tube box and the shell side cylinder in a horizontal direction in an extending manner, and the lower tube plate is arranged between the lower tube box and the shell side cylinder in a horizontal direction in an extending manner, wherein the upper tube plate, the lower tube plate and the shell side cylinder define a cold flow cavity for containing a first cooling medium; The lower side of the shell-side cylinder is provided with a cylinder inlet communicated with the cold flow cavity, the cylinder inlet is positioned above the lower tube plate, the upper side of the shell-side cylinder is provided with a cylinder outlet communicated with the cold flow cavity, and the cylinder outlet is positioned below the upper tube plate; the heat exchange tube is used for accommodating a high-temperature medium and is arranged in the cold flow cavity in an extending manner along the up-down direction; The anti-cavitation structure comprises a defoaming pipe and an anti-cavitation plate, the anti-cavitation plate is arranged in the cold flow cavity and located between the upper pipe plate and the cylinder body outlet in the up-down direction, the defoaming pipe is used for containing a second cooling medium, and the anti-cavitation plate is arranged in the defoaming pipe in a penetrating mode, and the outlet of the anti-cavitation plate protrudes out of the upper surface of the anti-cavitation plate. Optionally, the defoaming pipe comprises a first pipe section, a connecting bent pipe, a second pipe section and a connecting flange, wherein the first pipe section extends in the horizontal direction and penetrates out of the lower pipe box, the first pipe section comprises a first end positioned in the lower pipe box and a second end positioned outside the lower pipe box, and the connecting flange is connected to the second end of the first pipe section; The connecting bent pipe is arranged in the lower pipe box, the first end of the connecting bent pipe is connected with the first end of the first pi