阅读说明：本技术 一种低负荷一炉带两机的运行系统 (Low-load operation system with one furnace and two machines ) 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：本发明公开了一种低负荷一炉带两机的运行系统,包括两个单元制机组；其中,锅炉过热蒸汽通过主蒸汽管道联通到一号汽轮机与二号汽轮机的高压缸进汽口,蒸汽流量通过调节阀、关断阀控制。一号汽轮机高压缸排汽通过再热再进入中压缸,而二号汽轮机高压缸排汽则直接进入中压缸。本发明以较为简单的结构,实现低负荷机组的母管制再热系统,具有较好的经济性与发展潜力,可以有效解决新能源电力大发展下火电机组长时间低负荷的运行需求。(The invention discloses a low-load operation system with two machines in one furnace, which comprises two unit-making machine sets; the superheated steam of the boiler is communicated to the high-pressure cylinder steam inlets of the first steam turbine and the second steam turbine through a main steam pipeline, and the steam flow is controlled through a regulating valve and a shutoff valve. The exhaust steam of the first turbine high-pressure cylinder enters the intermediate-pressure cylinder through reheating, and the exhaust steam of the second turbine high-pressure cylinder directly enters the intermediate-pressure cylinder. The main pipe reheating system of the low-load unit is realized by a simpler structure, has better economical efficiency and development potential, and can effectively meet the long-time low-load operation requirement of the thermal power unit under the condition of great development of new energy power.)

1. A low-load operation system with one furnace and two machines is characterized by comprising two unit-making machine sets, a main steam bypass connecting pipe and a high-pressure-intermediate pressure cylinder connecting pipe; the steam outlet of the high-pressure cylinder of the second steam turbine is communicated to the steam inlet of the intermediate-pressure cylinder of the second steam turbine through a high-pressure-intermediate-pressure cylinder connecting pipe, and the steam outlet of the intermediate-pressure cylinder of the second steam turbine is communicated to the low-pressure cylinder through a pipeline.

2. A low load operation system with two machines in one furnace according to claim 1, wherein the superheated steam of the first boiler is communicated to the steam inlet of the high pressure cylinder of the first steam turbine through the main steam pipeline and communicated to the steam inlet of the high pressure cylinder of the second steam turbine through the main steam bypass communication pipe, and the steam flow is controlled by the adjusting valve and the shutoff valve.

3. The operating system of claim 1, wherein the steam outlet of the high-pressure cylinder of the first steam turbine is communicated to the inlet main pipe of the low-temperature reheater of the first boiler through a steam communication pipe, the outlet main pipe of the low-temperature reheater of the first boiler is communicated to the steam inlet of the intermediate-pressure cylinder of the first steam turbine through a first reheating pipeline, and the steam outlet of the intermediate-pressure cylinder of the first steam turbine is communicated to the low-pressure cylinder through a pipeline.

4. The system of claim 1, wherein the low-load one-furnace-with-two-machine operation system is characterized in that the inlet main pipe of the low-temperature reheater is provided with temperature-reducing water, and the flow rate of steam in the reheater pipe is 35m/s-60 m/s.

5. The system of claim 1, further comprising a second boiler, wherein the second boiler is in a shutdown or hot standby state, and both turbines are in operation.

6. The operating system of claim 1, wherein both units are in a grid-connected power generation state, and the two units share the electrical load command.

7. The operating system of claim 1, wherein the first unit operates under high load and the second unit operates under low load.

8. A low-load operation system with two machines in one furnace is characterized in that before the second boiler is started, a shut-off valve of a main steam pipeline between the first boiler and the second steam turbine is closed, and the normal operation state of one furnace and one machine is recovered.

Technical Field

The invention belongs to the field of thermal power generation, and particularly relates to a low-load operation system with two machines in one furnace.

Background

At present, the scales of wind power and photovoltaic power generation are gradually enlarged, and for thermal power generation, the wind power photovoltaic power generation which ensures lower load operation capacity to make up for the problem of incapability of generating power stably is more and more important. The increase of new forms of energy generated energy can cause very big impact to existing thermal power generating unit, and in order to adapt to more and more new forms of energy electric power, the flexibility transformation needs to be carried out to existing thermal power generating unit to reinforcing degree of depth peak regulation ability. At present, the flexible peak regulation modification generally adopts a thermoelectric decoupling mode, which has certain limitation, firstly, the output of a boiler is not reduced, namely, the coal burning quantity is not reduced, and the carbon emission is not reduced; secondly, the power plant must also have significant thermal consumers around it.

For the existing thermal power generation system, because the boiler can not be operated at low load for a long time, and the existing domestic large-capacity power station unit adopts a steam intermediate reheating system, unit systems are 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 generation unit, and when the unit operates 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.

For a main control system, namely a power generation system in which a plurality of units with the same parameters of water supply and superheated steam are respectively connected together by using a common pipeline, 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.

Disclosure of Invention

The invention aims to provide a low-load operation system with one furnace and two machines, aiming at the improvement requirement of the flexibility of the existing thermal power generating unit and enhancing the deep peak regulation capability.

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

a low-load operation system with one furnace and two machines comprises two unit-making units, a main steam bypass connecting pipe and a high-pressure-medium pressure cylinder connecting pipe; the steam outlet of the high-pressure cylinder of the second steam turbine is communicated to the steam inlet of the intermediate-pressure cylinder of the second steam turbine through a high-pressure-intermediate-pressure cylinder connecting pipe, and the steam outlet of the intermediate-pressure cylinder of the second steam turbine is communicated to the low-pressure cylinder through a pipeline.

The invention is further improved in that the superheated steam of the first boiler is communicated to the steam inlet of the high-pressure cylinder of the first steam turbine through a main steam pipeline and communicated to the steam inlet of the high-pressure cylinder of the second steam turbine through a main steam bypass communication pipe, and the steam flow is controlled by a regulating valve and a shutoff valve.

The invention is further improved in that the steam outlet of the high-pressure cylinder of the first steam turbine is communicated to the inlet main pipe of the low-temperature reheater of the first boiler through a steam communication pipe, the outlet main pipe of the low-temperature reheater of the first boiler is communicated to the steam inlet of the intermediate-pressure cylinder of the first steam turbine through a reheating pipeline, and the steam outlet of the intermediate-pressure cylinder of the first steam turbine is communicated to the low-pressure cylinder through a pipeline.

The invention is further improved in that the inlet main pipe of the low-temperature reheater is provided with temperature-reducing water, and the flow velocity of steam in the reheater pipeline is 35-60 m/s.

The invention has the further improvement that the system also comprises a second boiler, wherein the second boiler is in a shutdown or hot standby state, and both the two turbines are in a running state.

The invention has the further improvement that the two units are in a grid-connected power generation state, and the two units share the power load instruction.

The invention has the further improvement that the first unit runs under high load and the second unit runs under low load.

The invention is further improved in that before the second boiler is started, the shut-off valve of the main steam pipeline between the first boiler and the second steam turbine is closed, and the normal operation state of one boiler and one machine is recovered.

The invention has at least the following beneficial technical effects:

in the invention, the steam outlet of the high-pressure cylinder of the second steam turbine is communicated to the steam inlet of the intermediate-pressure cylinder of the second steam turbine through the high-pressure-intermediate-pressure cylinder connecting pipe, and the steam outlet of the intermediate-pressure cylinder of the second steam turbine is communicated to the low-pressure cylinder through a pipeline. The superheated steam of the first boiler is communicated to a high-pressure cylinder steam inlet of the first steam turbine through a main steam pipeline, is communicated to a high-pressure cylinder steam inlet of the second steam turbine through a main steam bypass connecting pipe, and the steam flow is controlled through a regulating valve and a shutoff valve. Compared with the existing unit reheating system, the invention uses the main pipe system to realize the operation mode of one furnace with two machines, so as to ensure the safe operation of the generator set under low load and enhance the deep peak regulation capability of the power plant.

Drawings

FIG. 1 is a schematic view of a low-load one-furnace two-machine operation system of the present invention.

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 low-load one-furnace two-machine operation system provided by the invention comprises two unit-making units, a main steam bypass connecting pipe, a high-pressure-medium pressure cylinder connecting pipe, a regulating valve and a shut-off valve. Wherein: the superheated steam of the first boiler is communicated to a high-pressure cylinder steam inlet of the first steam turbine through a main steam pipeline and communicated to a high-pressure cylinder steam inlet of the second steam turbine through a main steam bypass communication pipe, and the steam flow is controlled through a regulating valve and a shutoff valve, so that the generated energy of the two units is controlled. The steam outlet of the high-pressure cylinder of the first steam turbine is communicated to an inlet main pipe of a low-temperature reheater of the first boiler through a pipeline, desuperheating water is arranged on the inlet main pipe, the steam flow rate in the low-temperature reheater and the high-temperature reheater is 35m/s-60m/s, an outlet main pipe of the low-temperature reheater of the first boiler is communicated to a steam inlet of a medium-pressure cylinder of the first steam turbine through a first reheating pipeline, and a steam outlet of the medium-pressure cylinder of the first steam turbine is communicated to a low-pressure cylinder through a pipeline; the steam outlet of the high-pressure cylinder of the second steam turbine is communicated to the steam inlet of the intermediate-pressure cylinder of the second steam turbine through a high-pressure-intermediate-pressure cylinder connecting pipe. In order to avoid safety problems when the steam with different parameters is mixed, the steam outlet of the high-pressure cylinder of the second steam turbine with lower load is directly communicated to the steam inlet of the intermediate-pressure cylinder of the second steam turbine through a pipeline, and the steam outlet of the intermediate-pressure cylinder of the second steam turbine is communicated to the low-pressure cylinder through a pipeline. At this time, the second boiler can be kept in a safe shutdown state or in a hot standby state.

Because the main steam of the boiler is communicated with the two turbines, compared with a unit system unit, the exhaust steam flow of a high-pressure cylinder of a single turbine is correspondingly reduced, so that the high exhaust pressure is reduced, the steam density is reduced, and the volume flow is increased on the premise of keeping the mass flow unchanged. In order to avoid overlarge steam flow velocity in the reheater, the invention adopts a single steam turbine reheating mode to reduce the mass flow of the steam in the reheater and ensure that the steam flow velocity in the reheater is controlled to be 35m/s-60 m/s. Meanwhile, the temperature of steam at the inlet of the reheater is coordinately controlled by the desuperheating water, so that the overheating of the reheater is avoided.

The two sets are in a grid-connected power generation state, the two sets share an electric load instruction, the first set runs at a high load, and the second set runs at a low load. Before the second boiler is started, a shut-off valve of a main steam pipeline between the first boiler and the second steam turbine is closed, and the normal running state of one boiler and one machine is recovered.

In conclusion, compared with other main pipe system, the low-load operation system with one furnace and two machines has a simpler structure, and compared with a conventional thermal power generating unit, the low-load operation system with one furnace and two machines only increases a communication pipeline for communicating superheated steam of a boiler to another steam turbine and a matched flow regulating valve and a matched shutoff valve, has lower cost, and is a main pipe reheating system which is easier to realize.

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.