Superheat segment structure increasing input rate of high-pressure heater

Abstract

The invention relates to the field of high-pressure heaters and discloses a superheat segment structure increasing the input rate of a high-pressure heater. The superheat segment structure comprises ashell and a steam inlet; a pipe plate is arranged on one side of the shell; a U-shaped pipe is arranged in the shell, and an end port of the U-shaped pipe is fixed to the pipe plate; a heat hiding plate is arranged between the pipe plate and a superheat segment; the steam inlet is located on the portion, nearby the pipe plate, of the shell; and below the steam inlet, a plurality of anti-scouringrods are arranged above the U-shaped pipe side by side. Although an anti-scouring baffle arranged at the steam inlet position in the prior art has a certain steam blocking effect, blocked steam afterbeing bent in direction can still directly scour the portion, on the most periphery, of the U-shaped pipe; after the anti-scouring rods of the superheat segment structure are arranged, after superheatsteam enters the superheat segment structure, the superheat steam firstly scours the anti-scouring rods and then flows to the U-shaped pipe on the lower portion, and therefore the situation that theU-shaped pipe is directly scoured is avoided, and a large effect is achieved for inhibiting thinning of the pipe wall.

Description

technical field [0001] The invention relates to the field of high-pressure heaters, in particular to the structure of the superheating section of the high-pressure heater. Background technique [0002] High-pressure heater is an important equipment in the feed water recuperation system of thermal power plant and nuclear power plant, and its performance and reliability directly affect the economy and safety of unit operation. In recent years, the number of high-parameter and large-capacity units has increased continuously, and the frequent start-up and sharp load changes of the units have made the operating conditions of the heaters worse and worse. In the actual operation of the high-pressure heater, once a leak occurs, it must be withdrawn from operation and repaired. Through the investigation of high-pressure heaters that have been in operation at home and abroad, we found that the tube bundles of high-pressure heaters are prone to damage: (1) The outermost two or three r...

AI Technical Summary

Problems solved by technology

[0003] Specifically, there are many reasons for the leakage of high-pressure heaters. Only from the design point of view, the following three aspects are more common: (1) Scouring erosion: when the steam flow path is small and the steam flow rate is high, especially when the steam contains water Long-term erosion of fog and soda water will gradually thin the outer wall of the pipe. Under the action of thermal stress and pressure difference of soda water, the weak part of the U-shaped pipe will appear bulging, cracking or even blasting, resulting in leakage; (2) pipe vibration: the length of the free section of the pipe bundle ( unsupported span) is too long, and when the steam flow rate is high, the tube bundle will vibrate under the action of steam disturbance force. When the frequency of the exciting force matches the natural frequency of the tube bundle or its multiple, it will cause the tube bundle to resonate, and the amplitude will increase greatly, resulting in damage to the tube bundle. Leakage occurs; (3) The minimum bending radius of the U-shaped tube at the center of the tube bundle is small, the deformation of the bent tube is large during manufacturing, the local tube wall is thinned, and the tube wall is washed away during operation, which is easy to damage

[0004] The above-mentioned reasons are mainly due to the following deficiencies in the structure of the superheating section of the existing high-pressure heater: (1) Although the anti-scour baffle design is adopted at the steam inlet, the most peripheral pipes are still severely scoured by steam water (the anti-scour baffle It can be seen that the steam baffle plate (5) referred to in the Chinese Patent Announcement No. CN2753964Y); (2) the outlet of the superheated section is prone to high steam flow rate, high humidity, and soda scour; (3) the length of the free section of the tube bundle (unsupported span) Large, easy to generate vibration; (4) The minimum bending radius of the U-shaped tube at the center of the tube bundle is small, and the local tube wall is thin, so the U-shaped tube is easily damaged during operation

Images