CN209510396U - A thermodynamic system with one furnace and two machines switching operation - Google Patents

Abstract

This utility model provides a thermal system for switching between one boiler and two turbines. It primarily solves the problem that in traditional power plant boilers, the entire unit is forced to shut down when the main equipment fails. Under the premise of one boiler supporting one turbine, if both turbines are at low loads (the total load of the two turbines is not less than the minimum stable combustion load of one boiler and not greater than the maximum load of one boiler), one boiler can be shut down, and the remaining boiler can simultaneously supply steam to both turbines. Furthermore, when one boiler is supplying steam to two turbines, another boiler can be started to complete the online switching from "one boiler supporting two turbines" to "one boiler supporting one turbine." These functions can be achieved by adding bypass pipelines and corresponding valve configurations. This improves the flexibility and economy of unit operation.

Description

A thermodynamic system with one furnace and two machines switching operation

technical field

The invention relates to the technical field of thermoelectric power generation, in particular to a thermodynamic system with one furnace and two machines switching operation.

Background technique

Since modern large-capacity power plant units adopt the steam intermediate reheating method, they generally adopt a unit system, that is, each boiler directly supplies steam to a matched steam turbine, and the steam turbine drives the generator, forming an independent unit of furnace-mechanical-electrical vertical connection , there is no large horizontal connection between independent units. When the unit is in normal operation, the steam and plant power required by this unit are taken from this unit.

Compared with the non-unit system adopted by general small-capacity units (main control system, that is, a power generation system in which multiple units with the same parameters of feed water and superheated steam are connected to the first-stage power generation system with public pipelines), the unit unit system Simple, short pipeline, less pipeline accessories, less investment, high reliability of the system itself, convenient operation, easy to start and stop by sliding parameters, suitable for centralized control of furnace, machine and electricity.

The disadvantage of the unit system is that when any major equipment fails, the entire unit will be forced to stop running, adjacent units cannot support each other, and machines and furnaces cannot switch between operations, and the flexibility of operation is poor; when the system When the frequency changes, the unit unit has poor adaptability to the load due to the large thermal inertia of the boiler.

Contents of the invention

The purpose of the present invention is to solve the above-mentioned problems in the prior art, and further provide a thermal system with one furnace and two switching machines, in which adjacent thermal units can support each other, and the furnaces can also be switched to operate Good flexibility; strong adaptability to load, when the load of the entire power plant is lower than the full load of a single unit, when a certain boiler stops operating due to failure, the corresponding steam turbine can continue to run without stopping, improving It improves the flexibility and economy of unit operation.

The purpose of the present invention is achieved through the following technical solutions:

A thermal system with one furnace and two machines switching operation, including No. 1 boiler, No. 2 boiler, No. 1 steam turbine, and No. 2 steam turbine. The main steam pipeline is connected to the steam inlet of the high-pressure cylinder of steam turbine No. 1, and the steam outlet of the high-pressure cylinder of steam turbine No. 1 is connected to the inlet main pipe of the low-temperature reheater of the No. The pipe is connected to the steam inlet of the medium-pressure cylinder of the steam turbine No. 1 through the No. 1 reheat pipe, and the steam outlet of the medium-pressure cylinder of the No. 1 steam turbine is connected to the low-pressure cylinder through the pipeline;

No. 2 boiler feeds water through the pipeline, and the steam outlet of the No. 2 boiler is connected to the steam inlet of the No. 2 steam turbine high-pressure cylinder through the No. 2 main steam pipeline, and the steam outlet of the No. 2 steam turbine high-pressure cylinder is connected to the No. 2 boiler through a pipeline. On the inlet main pipe of the low-temperature reheater, the outlet main pipe of the low-temperature reheater of the No. 2 boiler is connected to the steam inlet of the medium-pressure cylinder of the No. 2 steam turbine through the No. The port is connected to the low-pressure cylinder through the pipeline;

Wherein, the No. 1 main steam pipeline leads to a bypass pipeline connected to the No. 2 main steam pipeline, and the bypass pipeline is provided with a regulating valve and a shut-off valve, and the No. 1 reheat pipeline leads to a bypass pipeline. The pipeline is connected to the No. 2 reheat pipeline and a regulating valve and a shut-off valve are set on the bypass pipeline. The steam outlet of the high-pressure cylinder of the No. 1 steam turbine is connected to the main pipe of the low-temperature reheater inlet of the No. 1 boiler. The bypass pipe leading out of the pipe is connected to the pipe connecting the steam outlet of the high-pressure cylinder of the No. 2 steam turbine and the inlet main pipe of the low-temperature reheater of the No. 2 boiler, and a regulating valve and a shut-off valve are installed on the bypass pipe;

The No. 1 main steam pipe, No. 1 reheat pipe, No. 1 steam turbine high-pressure cylinder steam outlet connected to the No. 1 boiler’s low-temperature reheater inlet main pipe are all provided with regulating valves on the side close to the No. 1 steam turbine. The No. 2 main steam pipe, the No. 2 reheat pipe, and the No. 2 steam turbine high-pressure cylinder outlet connected to the No. 2 boiler's low-temperature reheater inlet main pipe are all set on the side close to the No. 2 boiler There are regulating valves and shut-off valves.

The beneficial effects of the present invention are: by adopting the technical scheme of the present invention, compared with the existing large-capacity unitary units, the "one furnace with two machines" system adopted in the present invention can realize that the load of the entire power plant is lower than that of a single unit When a boiler is at full load, when a certain boiler is out of operation due to a failure, the corresponding steam turbine can continue to run without stopping, which improves the flexibility and economy of unit operation.

Description of drawings

Fig. 1 is a schematic diagram of the system structure principle of the present invention.

Detailed ways

The present invention will be described in further detail below in conjunction with the accompanying drawings: the present embodiment is implemented on the premise of the technical solution of the present invention, and detailed implementation is provided, but the protection scope of the present invention is not limited to the following embodiments.

As shown in Figure 1, a thermal system with one furnace and two machines switching operation involved in this embodiment includes No. 1 boiler, No. 2 boiler, No. 1 steam turbine, and No. 2 steam turbine. The steam outlet of the No. 1 boiler is connected to the steam inlet of the No. 1 steam turbine high-pressure cylinder through the No. 1 main steam pipeline, and the steam outlet of the No. 1 steam turbine high-pressure cylinder is connected to the low-temperature reheater of the No. 1 boiler through a pipeline. On the inlet main pipe, the outlet main pipe of the low-temperature reheater of the No. 1 boiler is connected to the steam inlet of the medium-pressure cylinder of the No. 1 steam turbine through the No. 1 reheat pipe, and the steam outlet of the medium-pressure cylinder of the No. 1 steam turbine is connected through the pipeline to the low pressure cylinder;

No. 2 boiler feeds water through the pipeline, and the steam outlet of the No. 2 boiler is connected to the steam inlet of the No. 2 steam turbine high-pressure cylinder through the No. 2 main steam pipeline, and the steam outlet of the No. 2 steam turbine high-pressure cylinder is connected to the No. 2 boiler through a pipeline. On the inlet main pipe of the low-temperature reheater, the outlet main pipe of the low-temperature reheater of the No. 2 boiler is connected to the steam inlet of the medium-pressure cylinder of the No. 2 steam turbine through the No. The port is connected to the low-pressure cylinder through the pipeline;

Wherein, the No. 1 main steam pipeline leads to a bypass pipeline connected to the No. 2 main steam pipeline, and the bypass pipeline is provided with a regulating valve and a shut-off valve, and the No. 1 reheat pipeline leads to a bypass pipeline. The pipeline is connected to the No. 2 reheat pipeline and a regulating valve and a shut-off valve are set on the bypass pipeline. The steam outlet of the high-pressure cylinder of the No. 1 steam turbine is connected to the main pipe of the low-temperature reheater inlet of the No. 1 boiler. The bypass pipe leading out of the pipe is connected to the pipe connecting the steam outlet of the high-pressure cylinder of the No. 2 steam turbine and the inlet main pipe of the low-temperature reheater of the No. 2 boiler, and a regulating valve and a shut-off valve are installed on the bypass pipe;

The No. 1 main steam pipe, No. 1 reheat pipe, No. 1 steam turbine high-pressure cylinder steam outlet connected to the No. 1 boiler’s low-temperature reheater inlet main pipe are all provided with regulating valves on the side close to the No. 1 steam turbine. The No. 2 main steam pipe, the No. 2 reheat pipe, and the No. 2 steam turbine high-pressure cylinder outlet connected to the No. 2 boiler's low-temperature reheater inlet main pipe are all set on the side close to the No. 2 boiler There are regulating valves and shut-off valves.

Specifically, if there are 2 units with the same parameters, on the premise that one boiler with one unit is satisfied, if the two turbines are at a relatively low load (the total load of the two turbines is not less than the minimum stable combustion load of one boiler, and is not greater than The maximum load of one boiler), one boiler can be stopped, and the remaining one boiler can supply steam to two turbines at the same time; in addition, when one boiler supplies steam to two turbines, another boiler can be started to complete Online switching from "one furnace with two machines" to "one furnace with one machine"; the above functions can be realized by adding bypass pipes and corresponding valve configurations.

The main steam from the No. 1 boiler enters the main steam pipeline, and part of the main steam enters the high-pressure cylinder of the No. 1 steam turbine to do work. A bypass pipe is drawn from the main steam pipeline to connect to the high-pressure cylinder of the No. 2 steam turbine, and the remaining main steam is introduced into the No. 2 steam turbine. The high-pressure cylinder of the steam turbine works; set a regulating valve on the steam inlet pipe of the No. 1 steam turbine, and set a regulating valve and a shut-off valve on the intake pipe of the No. 2 steam turbine; the exhaust steam of the high-pressure cylinders of the two steam turbines merges into the cold re-entry main pipe , set a regulating valve on the high exhaust steam pipeline of the No. 1 steam turbine, set a regulating valve and a shut-off valve on the high exhaust steam pipeline of the No. 2 steam turbine; The exhausted reheat steam enters the heat re-export main pipe, and part of the reheat steam in the hot section enters the intermediate pressure cylinder of No. 1 steam turbine to do work. In addition, a bypass pipe is drawn from the heat re-export main pipe to connect to the intermediate pressure cylinder of No. 2 steam turbine. The remaining reheated steam in the hot section is introduced into the intermediate pressure cylinder of No. cut off valve.

In the above process, if the load of No. 1 steam turbine is high and the load of No. 2 steam turbine is low, the pressure of the reheat steam coming out of the high-pressure cylinder of No. Mismatch may cause low-pressure steam to be difficult to discharge. At this time, the high discharge pressure of No. 2 steam turbine must be adjusted to be consistent with that of No. 1 steam turbine through the middle regulating valve of the No. Inlet parent pipe.

In addition, when No. 1 boiler supplies steam to 2 steam turbines at the same time, if it is necessary to realize the online switching function of No. 1 boiler with No. 1 steam turbine and No. 2 boiler with No. Regulating valves and shut-off valves are installed on the inlet pipeline and the heat re-export pipeline. Slowly adjust the load of each furnace, pipeline flow, working fluid parameters, etc., and close each bypass shut-off valve after the conditions are met.

The above are only preferred specific implementations of the present invention. These specific implementations are all based on different implementations under the overall concept of the present invention, and the scope of protection of the present invention is not limited thereto. Anyone familiar with the technical field Within the technical scope disclosed in the present invention, any changes or substitutions that can be easily conceived by a skilled person shall fall within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the protection scope of the claims.

Claims (1)

1. a kind of two machine switchover operation therrmodynamic system of a furnace zone, including No.1 boiler, No. two boilers, No.1 steam turbine, No. two vapour Turbine, which is characterized in that No.1 boiler passes through No.1 main steam pipe by pipeline water supply, the No.1 Boiler Steam venthole Road is connected to No.1 steam turbine high-pressure cylinder air intake, and No.1 steam turbine high-pressure cylinder venthole is connected to No.1 boiler by pipeline In low-temperature reheater entrance main pipe, the outlet main pipe of the low-temperature reheater of No.1 boiler is connected to No.1 by No.1 reheating pipeline The intermediate pressure cylinder venthole of the intermediate pressure cylinder air intake of steam turbine, No.1 steam turbine passes through pipeline connection to low pressure (LP) cylinder；

No. two boilers are connected to No. two by No. two main steam lines by pipeline water supply, No. two Boiler Steam ventholes Steam turbine high-pressure cylinder air intake, No. two steam turbine high-pressure cylinder ventholes are entered by the low-temperature reheater that pipeline is connected to No. two boilers In mouth main pipe, the outlet main pipe of the low-temperature reheater of No. two boilers is connected to the middle pressure of No. two steam turbines by No. two reheating pipelines The intermediate pressure cylinder venthole of cylinder air intake, No. two steam turbines passes through pipeline connection to low pressure (LP) cylinder；

Wherein, bypass duct is led on the No.1 main steam line to be connected on No. two main steam lines and in the bypass It is provided with regulating valve, shut-off valve on pipeline, bypass duct is led on No.1 reheating pipeline and is connected on No. two reheating pipelines simultaneously Regulating valve, shut-off valve are provided on the bypass duct, the No.1 steam turbine high-pressure cylinder venthole is low with No.1 boiler Bypass duct and No. two steam turbine high-pressure cylinder ventholes and No. two boilers are drawn on the pipeline of warm reheater entrance main pipe connection The pipeline connection of low-temperature reheater entrance main pipe connection, and regulating valve, shut-off valve are provided on the bypass duct；Described one Number main steam line, No.1 reheating pipeline, No.1 steam turbine high-pressure cylinder venthole connection No.1 boiler low-temperature reheater entrance Be provided with regulating valve in the side close to No.1 steam turbine on the pipeline of main pipe, No. two main steam lines, No. two again Close to two on the pipeline for the low-temperature reheater entrance main pipe that heat pipeline, No. two steam turbine high-pressure cylinder ventholes are connected to No. two boilers The side of number boiler is provided with regulating valve and shut-off valve.