Ultra-supercritical secondary reheating boiler purging system

Abstract

The utility model relates to the technical field of boiler steam purging, in particular to an ultra-supercritical secondary reheat boiler purging system. Comprising a separator, a superheater, a first temporary blowing valve, a second temporary blowing valve, a superheater target plate device, a primary reheater inlet particle collector, a primary reheater, a primary reheater target plate device, a secondary reheater inlet particle collector, a secondary reheater, a secondary reheater target plate device, a temporary high bypass valve, a temporary middle bypass valve and a silencer. According to the utility model, before each stage of pressure-stabilizing purging, the superheater is purged independently, so that not only are the problems of low purging coefficient and poor purging effect of the superheater during pressure-stabilizing purging of the secondary reheating boiler solved, but also the excessive flushing of the primary reheater and the secondary reheater is effectively avoided, and the service life of the secondary reheating boiler is prolonged. And the operation safety of the primary reheater and the secondary reheater is ensured.

Description

Technical Field

[0001] This utility model relates to the field of boiler steam purging technology, and in particular to a purging system for ultra-supercritical double reheat boilers. Background Technology

[0002] Boiler steam purging is a crucial step before the commissioning of thermal power generating units. Its purpose is to remove foreign objects from the boiler's heating surfaces, ensuring long-term safe and stable operation after commissioning. Compared to single reheat units, double reheat units have an additional stage of circulation, a more complex heating surface arrangement, and greater system resistance. When using a "single-stage" reduced-pressure steam purging method, double reheat units require high pre-purge system pressure, have long purging cycles, short effective time, and high fuel consumption. Ultra-supercritical double reheat units often employ pressure-stabilized purging.

[0003] The pressure-stabilizing purging system of a double reheat unit connects the superheater, primary reheater, secondary reheater, and steam pipelines in series: Superheater → Emergency Blow Valve → Target Plate → Particle Collector → Primary Reheater → Target Plate → Particle Collector → Secondary Reheater → Target Plate → Silencer. In this pressure-stabilizing purging method, particle collectors are installed at the inlets of both the primary and secondary reheaters. This results in high system resistance, with the superheater system itself having significantly greater resistance than the primary and secondary reheaters. The superheater temperature is lower than that of the primary and secondary reheaters, leading to a low purging coefficient and poor purging effect. Initially, the superheater struggles to reach the required purging coefficient. Conversely, the primary and secondary reheaters have lower resistance and higher steam temperatures. Even when the superheater's purging coefficient is below standard, the primary and secondary reheaters' purging coefficients are already ≥2, which is excessively high. This leads to excessive scouring of the primary and secondary reheaters, affecting their operational safety. Utility Model Content

[0004] In view of this, the main purpose of this utility model is to provide a purging system for an ultra-supercritical double reheat boiler, which can solve the problems of low superheater purging coefficient, poor purging effect, and excessive flushing of primary and secondary reheaters during the purging of existing double reheat units.

[0005] To achieve the above objectives, the technical solution of this utility model is implemented as follows:

[0006] A purge system for an ultra-supercritical double reheat boiler includes a separator, a superheater, an ultra-high pressure cylinder dummy valve core, a first temporary purge valve, a superheater target plate, a primary reheater, a high pressure cylinder dummy valve core, a primary reheater target plate, a secondary reheater, an intermediate pressure cylinder dummy valve core, a secondary reheater target plate, a second temporary purge valve, a temporary high pressure bypass valve, a temporary intermediate pressure bypass valve, and a silencer.

[0007] Steam is connected to the superheater via a pipeline after passing through the separator. The superheater outlet is divided into two paths. One of the purging paths is as follows: separator, superheater, ultra-high pressure cylinder dummy valve core, first temporary blow valve, superheater target plate, primary reheater, high pressure cylinder dummy valve core, primary reheater target plate, secondary reheater, intermediate pressure cylinder dummy valve core, secondary reheater target plate, silencer.

[0008] The other purging path is: separator, superheater, ultra-high pressure cylinder dummy valve core, second temporary purging valve, silencer.

[0009] Preferably, both the first and second pre-purge valves are equipped with bypass pipes and valves for warming up the valves before formal purging, and to prevent the first and second pre-purge valves from jamming.

[0010] Preferably, a primary reheater inlet particle collector is provided at the primary reheater inlet.

[0011] Preferably, a secondary reheater inlet particle collector is provided at the inlet of the secondary reheater.

[0012] The ultra-supercritical double reheat boiler purging system of this invention has the following beneficial effects:

[0013] In the specific operation of the ultra-supercritical double reheat boiler purging system described in this utility model, before the start of each stage of purging, the superheater is first purged 10 times using the purging path: superheater, ultra-high pressure cylinder dummy valve core, second temporary blow valve, silencer. This effectively removes impurities and oxide scale that has peeled off after the previous stage of boiler shutdown from the superheater, reducing the resistance of the superheater system. Then, the double reheat boiler is purged in series with pressure stabilization using the purging path: superheater, ultra-high pressure cylinder dummy valve core, first temporary blow valve, superheater target plate, primary reheater inlet particle collector, primary reheater, high pressure cylinder dummy valve core, primary reheater target plate, secondary reheater inlet particle collector, secondary reheater, intermediate pressure cylinder dummy valve core, secondary reheater target plate, silencer. This system not only effectively removes debris and scale from the superheater in each initial stage, reducing superheater resistance and increasing the superheater purging coefficient during pressure stabilization purging, but also enables the superheater purging coefficient to reach the target ahead of time during pressure stabilization purging of the secondary reheat boiler in series. The system purging pressure is low, effectively avoiding excessive flushing of the primary and secondary reheaters and ensuring the operational safety of the primary and secondary reheaters. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the purging system structure of an ultra-supercritical double reheat boiler according to one embodiment of the present disclosure.

[0016] [Explanation of Key Component Symbols]

[0017] 1. Separator; 2. Superheater; 3. Ultra-high pressure cylinder dummy valve core; 4. First temporary blow valve; 5. Superheater target plate; 6. Primary reheater inlet particle collector; 7. Primary reheater; 8. High pressure cylinder dummy valve core; 9. Primary reheater target plate; 10. Secondary reheater inlet particle collector; 11. Secondary reheater; 12. Intermediate pressure cylinder dummy valve core; 13. Secondary reheater target plate; 14. Second temporary blow valve; 15. Silencer; 16. Temporary high pressure bypass valve; 17. Temporary intermediate pressure bypass valve. Detailed Implementation

[0018] The method of this utility model will be further described in detail below with reference to the accompanying drawings and embodiments.

[0019] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0020] It should be noted that the terminology used herein is for the purpose of describing specific embodiments only and is not intended to limit the exemplary embodiments according to this application. The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products, or devices.

[0021] See Figure 1 This utility model provides a technical solution:

[0022] A purge system for an ultra-supercritical double reheat boiler includes a separator 1, a superheater 2, an ultra-high pressure cylinder dummy valve core 3, a first temporary purge valve 4, a superheater target plate 5, a primary reheater 7, a high pressure cylinder dummy valve core 8, a primary reheater target plate 9, a secondary reheater 11, an intermediate pressure cylinder dummy valve core 12, a secondary reheater target plate 13, a second temporary purge valve 14, a temporary high pressure bypass valve 16, a temporary intermediate pressure bypass valve 17, and a silencer 15.

[0023] Steam is connected to superheater 2 via a pipeline through separator 1. The outlet of superheater 2 is divided into two paths. One of the purging paths is: superheater 2, ultra-high pressure cylinder dummy valve core 3, first temporary blow valve 4, superheater target plate 5, primary reheater 7, high pressure cylinder dummy valve core 8, primary reheater target plate 9, secondary reheater 11, intermediate pressure cylinder dummy valve core 12, secondary reheater target plate 13, silencer 15. The components in this purging path are connected by pipelines in the purging sequence, which can be used for reheat boiler series pressure stabilization purging.

[0024] The other purging path is: superheater 2, ultra-high pressure cylinder dummy valve core 3, second temporary blow valve 14, and silencer 15. The components in this purging path are connected by pipes in the purging sequence. Superheater 2 is purged 10 times separately through this purging path, which effectively removes impurities and oxide scale that was peeled off after the previous shutdown in superheater 2, and reduces the system resistance of superheater 2.

[0025] The high-pressure bypass valve used during normal operation of the ultra-supercritical double reheat boiler is replaced by a temporary high-pressure bypass valve 16 during purging, which is used to control the steam pressure during high-pressure bypass purging.

[0026] The medium-pressure bypass valve used during normal operation of the ultra-supercritical double reheat boiler is replaced by a temporary medium-pressure bypass valve 17 during purging, which is used to control the steam pressure during medium-pressure bypass purging.

[0027] Both the first pre-purge valve 4 and the second pre-purge valve 14 are equipped with bypass pipes and valves for warming up the valves before formal purging, and to prevent the first pre-purge valve 4 and the second pre-purge valve (14) from getting stuck.

[0028] The inlet of the primary reheater 7 is equipped with a primary reheater inlet particle collector 6, which is used to collect impurity particles in the superheater 2 and the main steam pipeline.

[0029] The inlet of the secondary reheater 11 is equipped with a secondary reheater inlet particle collector 10, which is used to collect impurity particles in the primary reheater 7 and the primary reheat steam pipeline.

[0030] The specific operation process of this utility model is as follows:

[0031] The purging process for each stage of an ultra-supercritical double reheat boiler is divided into three steps:

[0032] Step 1: Purify the superheater system 10 times separately through the purging path: superheater 2, ultra-high pressure cylinder dummy valve core 3, second temporary blow valve 14 → silencer 15, effectively removing debris and oxide scale that peeled off after the previous shutdown.

[0033] Step 2: Open the first emergency blow valve 4 and close the second emergency blow valve 14.

[0034] Step 3: Purge the superheater 2, primary reheater 7, and secondary reheater 11 in series via the following purging path: superheater 2 → ultra-high pressure cylinder dummy valve core 3 → first temporary purging valve 4 → superheater target plate 5 → primary reheater inlet particle collector 6 → primary reheater 7 → high pressure cylinder dummy valve core 8 → primary reheater target plate 9 → secondary reheater inlet particle collector 10 → secondary reheater 11 → intermediate pressure cylinder dummy valve core 12 → secondary reheater target plate 13 → silencer 15.

[0035] Compared with existing technologies, this utility model has a novel and unique structure, is easy to operate, and has low cost. Before each stage of pressure stabilization and purging in an ultra-supercritical double reheat boiler, the superheater is purged separately. This can effectively solve the problems of low superheater purging coefficient, poor purging effect, and excessive flushing of the primary and secondary reheaters during pressure stabilization and purging of the double reheat boiler. At the same time, compared with conventional ultra-supercritical double reheat boiler pressure reduction purging, it saves infrastructure commissioning time and ensures the efficient and orderly progress of the project.

[0036] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the scope of protection of the present utility model.

Claims

1. A purging system for an ultra-supercritical double reheat boiler, characterized in that, include: Separator (1), superheater (2), ultra-high pressure cylinder dummy valve core (3), first temporary blow valve (4), superheater target plate (5), primary reheater (7), high pressure cylinder dummy valve core (8), primary reheater target plate (9), secondary reheater (11), intermediate pressure cylinder dummy valve core (12), secondary reheater target plate (13), second temporary blow valve (14), temporary high pressure bypass valve (16), temporary intermediate bypass valve (17) and silencer (15); Steam is connected to the superheater (2) via a pipeline through the separator (1). The outlet of the superheater (2) is divided into two paths. One of the purging paths is: superheater (2), ultra-high pressure cylinder dummy valve core (3), first temporary blow valve (4), superheater target plate (5), primary reheater (7), high pressure cylinder dummy valve core (8), primary reheater target plate (9), secondary reheater (11), intermediate pressure cylinder dummy valve core (12), secondary reheater target plate (13), silencer (15). The other purging path is: superheater (2), ultra-high pressure cylinder dummy valve core (3), second temporary purging valve (14), silencer (15).

2. The ultra-supercritical double reheat boiler purging system according to claim 1, characterized in that, Both the first and second temporary blow valves (4) are equipped with bypass pipes and valves.

3. The ultra-supercritical double reheat boiler purging system according to claim 1, characterized in that, The inlet of the primary reheater (7) is provided with a primary reheater inlet collector (6).

4. The ultra-supercritical double reheat boiler purging system according to claim 1, characterized in that, The secondary reheater (11) is equipped with a secondary reheater inlet collector (10).

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