阅读说明：本技术 一种母管制再热系统的再热器结构 (Reheater structure of header reheating system ) 是由 王远 赵帅 孟勇 赵永坚 王国忠 徐远纲 王慧青 刘振琪 王伟锋 王昭 于 2021-06-29 设计创作，主要内容包括：本发明公开了一种母管制再热系统的再热器结构,包括一号机组与二号机组两个单元制机组,蒸汽联络管,排汽联络管,再热器旁路,再热蒸汽联络管,减温减压阀与关断阀；其中,两台汽轮机高压缸出汽经混合后联通至一号锅炉的再热器入口母管与再热器旁路,蒸汽流量通过调节阀、关断阀控制,再热器旁路管道依次联通至低温再热器与高温再热器出口。本发明以相对简单的结构,在现有再热器结构的基础上进行改造以解决母管制再热系统中再热器管道内蒸汽流速超温的问题,有利于母管制再热系统的广泛应用,具有较好的经济性与发展潜力,可以有效解决风力发电或太阳能发电负荷较高时火电机组长时间低负荷的运行需求。(The invention discloses a reheater structure of a header reheating system, which comprises a first unit and a second unit, a steam connecting pipe, a steam exhaust connecting pipe, a reheater bypass, a reheated steam connecting pipe, a temperature and pressure reducing valve and a shutoff valve, wherein the first unit is connected with the second unit through the steam connecting pipe; the steam outlet of the high-pressure cylinder of the two steam turbines is communicated to a reheater inlet main pipe and a reheater bypass of the first boiler after being mixed, the steam flow is controlled by a regulating valve and a shut-off valve, and reheater bypass pipelines are sequentially communicated to outlets of a low-temperature reheater and a high-temperature reheater. The steam generator set reheating system is relatively simple in structure, is improved on the basis of the existing reheater structure to solve the problem that the flow speed of steam in a reheater pipeline in a main pipe reheating system is over-temperature, is beneficial to wide application of the main pipe reheating system, has good economical efficiency and development potential, and can effectively meet the long-time low-load operation requirement of a thermal power generating unit when the wind power generation load or the solar power generation load is high.)

1. A reheater structure of a header reheating system is characterized by comprising a first unit and a second unit, a steam connection pipe (1), a steam exhaust connection pipe (4), a reheater bypass (8) and a reheated steam connection pipe (11);

the superheated steam of a boiler passes through steam connecting pipe (1) and allies oneself with the high-pressure cylinder steam inlet to No. two steam turbines, No. two steam turbine high pressure steam extraction connecting pipe (4) UNICOM to the female pipe of the reheater entry of a boiler, reheater bypass (8) UNICOM reheater entry female pipe, low temperature reheater export and high temperature reheater export, the high temperature reheater export of a boiler is through reheat steam connecting pipe (11) UNICOM to the intermediate pressure jar steam inlet of No. two steam turbines.

2. A reheater structure in a main reheating system according to claim 1, characterized in that the first pressure and temperature reducing valve (2) is installed in the middle of the steam connection pipe (1).

3. A reheater structure in a header reheating system according to claim 2, characterized in that a second temperature and pressure reducing valve (6) is installed in the middle of the steam exhaust connecting pipe (4).

4. A reheater structure in a header reheating system according to claim 3, wherein the steam flow in the low-temperature reheater and the high-temperature reheater pipes is controlled by a third temperature and pressure reducing valve (7), a fourth temperature and pressure reducing valve (9) and a fifth temperature and pressure reducing valve (10).

5. A reheater structure of main heating system as claimed in claim 4 wherein the first (3), second (5) and third (13) shut-off valves in the regulation system are used to restore the main heating system to the common unit system before the second boiler is started.

6. A reheater structure in a header reheating system according to claim 5, wherein the high temperature reheater outlet of the boiler I is connected to the intermediate pressure cylinder inlet of the steam turbine II through a reheat steam connection pipe (11), and the steam flow is controlled by a sixth reducing and pressure valve (12) and a third shut-off valve (13).

7. The reheater structure of a header reheating system of claim 1, wherein desuperheating water is fed into the inlet of the low-temperature reheater of the first boiler to ensure that the steam flow rate in the reheater pipe is 35m/s-60 m/s.

8. The reheater structure of a main-pipe reheating system as claimed in claim 1, wherein the second boiler is in a shutdown or hot standby state, both units are in a grid-connected power generation state, and both units share an electrical load command.

Technical Field

The invention belongs to the field of thermal power generation, and particularly relates to a reheater structure of a header reheating system.

Background

The new energy power generation becomes a new trend of future power generation, the energy storage of the wind power generation and the solar power generation which are commonly used at present is a difficult problem which is difficult to overcome, and in order to deal with unstable environmental factors and ensure stable power generation, a common method is to utilize thermal power generation to make up for a low-load section of the new energy power generation. Therefore, it is increasingly important to ensure flexible peak shaving capability of thermal power generation. For the existing thermal power generating unit, because the boiler can not be operated at low load for a long time, and the domestic large-capacity power station unit adopts a steam intermediate reheating system at present, a unit system is adopted, namely, each boiler only supplies steam to one steam turbine matched with the boiler, then the steam turbine drives a generator to form an independent power generating unit, and when the unit is operated normally, the steam and the service power needed by the unit are only taken from the unit. Therefore, the load of the reheating unit cannot be lower than the minimum load of the boiler at present.

Therefore, flexible modification is needed to enhance the deep peak regulation capability of the thermal power generating unit. The main pipe system is a power generation system which connects a plurality of units with the same parameters of the feed water and the superheated steam together by using a common pipeline, so that the operation mode that one boiler is provided with two turbines can be realized, and the ultra-low load operation of a large-capacity thermal power generating unit can be realized. Therefore, the existing research provides an operation mode that the main steam of one boiler is used for feeding steam to two turbines, and the deep peak regulation capacity of the unit is effectively improved.

However, since the main steam flow of one furnace is shared by the two turbines, the high-pressure cylinder exhaust flow of a single turbine is also reduced as compared with the unit turbine group, and the high-pressure cylinder exhaust pressure is reduced, thereby increasing the high-pressure cylinder exhaust specific volume. After the exhaust steam of the high-pressure cylinders of the two steam turbines is converged, the volume flow is about 2 times of that of unit system operation, and the flow speed of the steam in the reheating pipeline is overspeed.

Disclosure of Invention

The invention aims to provide a reheater structure of a header reheating system aiming at the existing header reheating system.

In order to achieve the purpose, the invention adopts the following technical scheme:

a reheater structure of a header reheating system comprises a first unit and a second unit, a steam connecting pipe, a steam exhaust connecting pipe, a reheater bypass and a reheated steam connecting pipe;

the superheated steam of a boiler passes through the steam and connects the high-pressure jar steam inlet that leads to No. two steam turbines of union, and No. two steam turbines high pressure steam extraction connection pipe UNICOM to the female pipe of reheater entry of a boiler, the female pipe of reheater bypass UNICOM reheater entry, low temperature reheater export and high temperature reheater export, the high temperature reheater export of a boiler passes through the intermediate pressure jar steam inlet that reheat steam connection pipe UNICOM arrived No. two steam turbines.

The invention is further improved in that a first temperature and pressure reducing valve is arranged in the middle of the steam communication pipe.

The invention is further improved in that a second temperature and pressure reducing valve is arranged in the middle of the steam exhaust interconnecting pipe.

The steam flow in the pipeline of the low-temperature reheater and the high-temperature reheater is controlled by a third temperature-reducing and pressure-reducing valve, a fourth temperature-reducing and pressure-reducing valve and a fifth temperature-reducing and pressure-reducing valve.

The invention is further improved in that before the second boiler is started, a first shut-off valve, a second shut-off valve and a third shut-off valve in the system are adjusted to restore the main control system to a common unit control system.

The invention is further improved in that the outlet of the high-temperature reheater of the first boiler is communicated with the steam inlet of the intermediate pressure cylinder of the second steam turbine through a reheated steam communication pipe, wherein the steam flow is controlled by a sixth temperature and pressure reducing valve and a third shut-off valve.

The invention has the further improvement that the inlet of the low-temperature reheater of the boiler I is filled with temperature-reducing water, and the flow velocity of steam in a pipe of the reheater is ensured to be 35-60 m/s.

The invention has the further improvement that the second boiler is in a furnace shutdown or hot standby state, the two units are in a grid-connected power generation state, and the two units share the electric load instruction.

The invention has at least the following beneficial technical effects:

compared with the existing reheater structure, the invention can effectively solve the problem that the flow rate of steam in the reheating pipeline is overspeed in the header reheating system. The mixed high-pressure cylinder steam is distributed to a reheater inlet main pipe and a reheater bypass through a flow regulating valve and a shutoff valve, and then is mixed with a low-temperature reheater and a high-temperature reheater outlet, so that the steam flow rate in a pipeline of the low-temperature reheater and the high-temperature reheater is ensured to be within a safe range.

Drawings

FIG. 1 is a schematic diagram of a reheater configuration of a header reheat system of the present invention.

Description of reference numerals:

1-steam connecting pipe, 4-steam exhaust connecting pipe, 8-reheater bypass, 11-reheated steam connecting pipe, 2-first temperature and pressure reducing valve, 6-second temperature and pressure reducing valve, 7-third temperature and pressure reducing valve, 9-fourth temperature and pressure reducing valve, 10-fifth temperature and pressure reducing valve, 12-sixth temperature and pressure reducing valve, 3-first shut-off valve, 5-second shut-off valve and 13-third shut-off valve.

Detailed Description

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

Referring to fig. 1, the reheater structure of the header reheating system provided by the invention comprises a first unit and a second unit, a steam connecting pipe 1, a steam exhaust connecting pipe 4, a reheater bypass 8, a reheated steam connecting pipe 11, first to sixth temperature and pressure reducing valves 2, 6, 7, 9, 10 and 12, and first to third shutoff valves 3, 5 and 13. Wherein, the superheated steam of a boiler passes through steam connecting pipe 1 UNICOM to the high pressure cylinder steam inlet of No. two steam turbines, and No. two steam turbine high pressure steam extraction connecting pipe 4 UNICOMs are to the female pipe of the reheater entry of a boiler, and reheater bypass 8 UNICOMs female pipe of reheater entry, low temperature reheater export and high temperature reheater export. The middle of the steam connecting pipe 1 and the steam exhaust connecting pipe 4 is respectively provided with a first temperature and pressure reducing valve 2 and a second temperature and pressure reducing valve 6. The steam flow in the low-temperature reheater and the high-temperature reheater pipeline is controlled by a third temperature and pressure reducing valve 7, a fourth temperature and pressure reducing valve 9 and a fifth temperature and pressure reducing valve 10. The outlet of the high-temperature reheater of the first boiler is communicated to the steam inlet of the intermediate pressure cylinder of the second steam turbine through a reheat steam connecting pipe 11, and the steam flow is controlled through a sixth temperature and pressure reducing valve 12 and a first shutoff valve 13.

The steam flow in the pipeline of the low-temperature reheater and the high-temperature reheater is controlled through a flow regulating valve and a shutoff valve, desuperheating water is put into the inlet of the low-temperature reheater, redundant steam is discharged through a bypass and is completely mixed at the outlet of the reheater, so that the steam flow rate in the pipeline of the low-temperature reheater and the high-temperature reheater is controlled to be 35m/s-60m/s, and the steam flow rate is ensured to be in a safe range.

A second boiler in the system is in a boiler shutdown or hot standby state, the two units are in a grid-connected power generation state, and the two units share an electric load instruction. Before the second boiler is started, the first to third shut-off valves 3, 5 and 13 in the system are adjusted, and the main control system can be recovered to be a common unit system.

In conclusion, compared with the conventional reheater structure, the reheater structure of the header reheating system can effectively solve the problem that the steam flow speed in the reheating pipeline in the header reheating system is too high, and meanwhile, compared with the conventional reheater structure, the reheater structure is fewer in pipelines and lower in reconstruction cost, and is a reheater structure which can be applied to the header reheating system.

Although the invention has been described in detail hereinabove with respect to a general description and specific embodiments thereof, it will be apparent to those skilled in the art that modifications or improvements may be made thereto based on the invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.