阅读说明：本技术 一种汽轮机高压缸暖缸及缸切换控制优化方法 (Steam turbine high-pressure cylinder warming and cylinder switching control optimization method ) 是由 唐守伟 刘继勇 王新 张超 唐金鹤 史建 于 2021-09-07 设计创作，主要内容包括：本发明提出了一种汽轮机高压缸暖缸及缸切换控制优化方法,包括：第一步：选择合理的汽源接入到高压缸内；第二步：倒暖逻辑系统判断是否进行倒暖,若需要进行倒暖则高压缸倒暖自动投入,若不需要进行倒暖,则高压缸倒暖不投入；第三步：正暖逻辑系统判断是否进行正暖,若需要进行正暖则高压缸正暖自动投入,若不需要进行正暖,则高压缸正暖不投入；第四步：判断缸切换条件是否具备,若具备则自动投入缸切换,若不具备则待缸切换条件具备时投入缸切换,借此,本发明具有对高压缸暖缸汽源进行改造,缩短启动时间；对倒暖缸体设定温度、正暖逻辑优化,提高高压缸金属温度；对缸切换逻辑进行优化,实现自动缸切换的优点。(The invention provides a steam turbine high-pressure cylinder warming and cylinder switching control optimization method, which comprises the following steps: the first step is as follows: selecting a reasonable steam source to be connected into the high-pressure cylinder; the second step is that: the back-warming logic system judges whether back warming is carried out or not, if the back warming is required, the back warming of the high-pressure cylinder is automatically put into use, and if the back warming is not required, the back warming of the high-pressure cylinder is not put into use; the third step: the positive warming logic system judges whether positive warming is carried out or not, if the positive warming is required, the positive warming of the high-pressure cylinder is automatically put into use, and if the positive warming is not required, the positive warming of the high-pressure cylinder is not put into use; the fourth step: judging whether the cylinder switching condition is met, if yes, automatically switching the cylinders, and if not, switching the cylinders when the cylinder switching condition is met, thereby improving the high-pressure cylinder warming steam source and shortening the starting time; setting temperature of the reverse heating cylinder body, optimizing positive heating logic and improving metal temperature of the high-pressure cylinder; and the cylinder switching logic is optimized, and the advantage of automatic cylinder switching is realized.)

1. A steam turbine high-pressure cylinder warming and cylinder switching control optimization method is characterized by comprising the following steps:

the first step is as follows: selecting a reasonable steam source to be connected into the high-pressure cylinder;

the second step is that: the back-warming logic system judges whether back warming is carried out or not, if the back warming is required, the back warming of the high-pressure cylinder is automatically put into use, and if the back warming is not required, the back warming of the high-pressure cylinder is not put into use;

the third step: the positive warming logic system judges whether positive warming is carried out or not, if the positive warming is required, the positive warming of the high-pressure cylinder is automatically put into use, and if the positive warming is not required, the positive warming of the high-pressure cylinder is not put into use;

the fourth step: and judging whether the cylinder switching condition is met, if so, automatically switching the cylinders, and if not, switching the cylinders when the cylinder switching condition is met.

2. The method for controlling and optimizing the warming of the high-pressure cylinder and the cylinder switching of the steam turbine according to claim 1, wherein in the first step, a pipeline is led from a steam source device interface to a pipeline in front of a pre-warming adjusting electric door of the high-pressure cylinder, and a manual or electric isolating door is added to serve as a pre-warming steam source of the high-pressure cylinder;

a drainage manual door or a pneumatic door is added in front of and behind the isolation door;

adding a manual door or an electric door to the original reheating steam cold section to the high-pressure cylinder back-warming electric door;

and a drainage pipeline and a valve are added in front of and behind the high-discharge check valve.

3. The method as claimed in claim 1, wherein the back-warming logic system comprises a back-warming automatic input logic judgment module for the high-pressure cylinder, an automatic warm-pipe electric valve adjustment module in communication with the back-warming automatic input logic judgment module for the high-pressure cylinder, a high-pressure cylinder warm-stiffness parameter monitoring module in communication with the warm-pipe electric valve automatic adjustment module, and a high-pressure cylinder warm-stiffness end logic judgment module in communication with the high-pressure cylinder warm-stiffness parameter monitoring module.

4. The method according to claim 1, wherein the positive warming logic system comprises a positive warming automatic input logic judgment module of the high pressure cylinder, a high transfer gate automatic adjustment module in communication connection with the positive warming automatic input logic judgment module of the high pressure cylinder, a positive warming parameter monitoring module of the high pressure cylinder in communication connection with the high transfer gate automatic adjustment module, and a positive warming ending logic judgment module of the high pressure cylinder in communication connection with the positive warming parameter monitoring module of the high pressure cylinder.

5. The method for controlling and optimizing the cylinder warming and cylinder switching of the high-pressure cylinder of the steam turbine according to claim 1, wherein in the fourth step, the rotating speed of the steam turbine is more than or equal to 3000r/min, the opening degrees of the intermediate governing valves ICV1 and ICV2 are more than 40%, and the cylinder switching is automatically started when the load of the unit is in a range of 45-65 MW.

6. The method for controlling and optimizing the cylinder warming and cylinder switching of the high-pressure cylinder of the steam turbine according to claim 1, wherein in the third step, the metal temperature of the first stage of the high-pressure inner cylinder is 150 ℃ to 320 ℃, the high-pressure main steam valve MSV is in a closed state, and the normal warming is automatically put into use when the #2 main steam valve pre-opening valve is in an open state.

7. The method of claim 1, wherein in the second step, the high pressure bypass regulating valve is automatically switched, the high discharge check valve is commanded to be closed, and the back-warming is automatically switched when the pressure difference between the front and the back of the high discharge check valve is negative.

Technical Field

The invention belongs to the technical field of startup optimization control of a steam turbine of an ultra supercritical coal-fired unit, and particularly relates to a high-pressure cylinder warming and cylinder switching control optimization method of a steam turbine.

Background

At present, an ultra-supercritical steam turbine generator unit becomes a main unit of each large power grid, and bears increasingly heavy peak regulation tasks of the power grid, and needs to be started and stopped frequently. The quick and safe start and stop of the unit becomes an important means for controlling the cost and improving the benefit of a power generation enterprise. The 660MW and above ultra-supercritical units generally adopt a medium pressure cylinder starting mode. The starting of the intermediate pressure cylinder can avoid the high pressure cylinder from running under low flow, thereby reducing the thermal shock of the first stage of the high pressure cylinder and the high pressure steam outlet; the high-pressure cylinder is pre-warmed by utilizing the reverse warming steam, so that the starting time can be shortened by 4-6 hours, and the service life of the steam turbine is prolonged; the expansion of the unit and the expansion difference change of the high, medium and low pressure cylinders are relatively uniform, so that the reliability and the economical efficiency of the starting operation of the unit are improved.

However, in the cold-state starting process of the pressure cylinder in the ultra-supercritical unit, the problems of unreasonable pre-warming steam source and pre-warming logic of the high-pressure cylinder, unreasonable forward-warming logic of the impulse, unreasonable cylinder switching logic and the like exist, the starting time of the unit is prolonged, the problems of water impact, thermal impact of the high-pressure cylinder, high exhaust temperature, reverse power protection action in the cylinder switching process and the like are easily caused, and the safe operation of the unit is threatened.

Disclosure of Invention

The invention provides a steam turbine high-pressure cylinder warming and cylinder switching control optimization method, which shortens the starting time by modifying a high-pressure cylinder warming steam source; setting temperature of the reverse heating cylinder body, optimizing positive heating logic and improving metal temperature of the high-pressure cylinder; and optimizing the cylinder switching logic to realize automatic cylinder switching.

The technical scheme of the invention is realized as follows: a steam turbine high-pressure cylinder warming and cylinder switching control optimization method comprises the following steps:

the first step is as follows: selecting a reasonable steam source to be connected into the high-pressure cylinder;

the second step is that: the back-warming logic system judges whether back warming is carried out or not, if the back warming is required, the back warming of the high-pressure cylinder is automatically put into use, and if the back warming is not required, the back warming of the high-pressure cylinder is not put into use;

the third step: the positive warming logic system judges whether positive warming is carried out or not, if the positive warming is required, the positive warming of the high-pressure cylinder is automatically put into use, and if the positive warming is not required, the positive warming of the high-pressure cylinder is not put into use;

the fourth step: and judging whether the cylinder switching condition is met, if so, automatically switching the cylinders, and if not, switching the cylinders when the cylinder switching condition is met.

In the first step, a pipeline is led from a steam source device interface and connected to a pipeline in front of a high-pressure cylinder pre-warming adjusting electric door, and a manual or electric isolating door is added to serve as a high-pressure cylinder pre-warming steam source;

a drainage manual door or a pneumatic door is added in front of and behind the isolation door;

adding a manual door or an electric door to the original reheating steam cold section to the high-pressure cylinder back-warming electric door;

and a drainage pipeline and a valve are added in front of and behind the high-discharge check valve.

In a preferred embodiment, the back-warming logic system includes a high-pressure cylinder back-warming automatic input logic judgment module, a warm pipe electric valve automatic adjustment module in communication connection with the high-pressure cylinder back-warming automatic input logic judgment module, a high-pressure cylinder warm rigidity parameter monitoring module in communication connection with the warm pipe electric valve automatic adjustment module, and a high-pressure cylinder warm rigidity end logic judgment module in communication connection with the high-pressure cylinder warm rigidity parameter monitoring module.

As a preferred embodiment, the positive-warming logic system includes a high-pressure cylinder positive-warming automatic input logic judgment module, a high-pressure gate automatic adjustment module in communication connection with the high-pressure cylinder positive-warming automatic input logic judgment module, a high-pressure cylinder positive-warming parameter monitoring module in communication connection with the high-pressure gate automatic adjustment module, and a high-pressure cylinder positive-warming end logic judgment module in communication connection with the high-pressure cylinder positive-warming parameter monitoring module.

In a preferred embodiment, in the fourth step, the rotating speed of the steam turbine is more than or equal to 3000r/min, the opening degrees of the intermediate regulating valves ICV1 and ICV2 are more than 40%, and the load of the unit is automatically switched in the range of 45-65 MW.

In a preferred embodiment, in the third step, the high-pressure inner cylinder first-stage metal temperature is 150-320 ℃, the high-pressure main steam valve MSV is in a closed state, and the #2 main steam valve pre-opening valve is in an open state, and the normal heating is automatically started.

In a preferred embodiment, in the second step, the high-pressure bypass control valve is automatically turned on, the high-discharge check valve is commanded to be closed, and the back-to-back pressure difference of the high-discharge check valve is automatically turned on when the back-to-back pressure difference is negative.

After the technical scheme is adopted, the invention has the beneficial effects that:

the method optimizes the logic of the starting mode of the steam turbine intermediate pressure cylinder on the basis of the control system of the ultra-supercritical coal-fired unit. The automatic control of the reverse warming of the high-pressure cylinder, the positive warming of the high-pressure cylinder and the switching of the high-intermediate pressure cylinder is realized, the workload of operators is reduced, abnormal events such as water impact, high-exhaust-temperature overrun tripping and reverse power protection action tripping caused by improper manual operation are avoided, and the safe starting target of the unit is ensured. Meanwhile, the cylinder and the rotor can be uniformly heated; the matching of the steam and the metal temperature is easy to realize; the high and medium pressure rotors can rapidly pass through the brittle fission temperature; the temperature level of the low-pressure cylinder is inhibited, and the safety of the low-pressure rotor is improved; the problems of unsmooth expansion of the cylinder body and the like when the unit is started are avoided; the ability of adapting to special working conditions is enhanced.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a schematic flow diagram of the present invention;

FIG. 2 is a flow chart of the optimization of the high-pressure cylinder back-warming control;

FIG. 3 is a flow chart of the high pressure cylinder positive warm logic optimization.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1 to 3, a method for controlling and optimizing high-pressure cylinder warming and cylinder switching of a steam turbine includes:

the first step is as follows: selecting a reasonable steam source to be connected into the high-pressure cylinder;

the second step is that: the back-warming logic system judges whether back warming is carried out or not, if the back warming is required, the back warming of the high-pressure cylinder is automatically put into use, and if the back warming is not required, the back warming of the high-pressure cylinder is not put into use;

the third step: the positive warming logic system judges whether positive warming is carried out or not, if the positive warming is required, the positive warming of the high-pressure cylinder is automatically put into use, and if the positive warming is not required, the positive warming of the high-pressure cylinder is not put into use;

the fourth step: and judging whether the cylinder switching condition is met, if so, automatically switching the cylinders, and if not, switching the cylinders when the cylinder switching condition is met.

The high-pressure cylinder can be warmed in advance, and the stable rise of the cylinder temperature is facilitated (the high-pressure cylinder is not limited by the main steam pressure and the temperature of a boiler in the starting process), so that the starting time of a unit is shortened; the positive heating logic in the process of impact rotation can be reasonably optimized, the temperature of the high-pressure cylinder is increased, and the low temperature of the high-pressure cylinder is avoided when the cylinders are switched; the stable switching of a high-pressure regulating valve, a high-discharge check valve, a high-low side pressure reducing valve and the like in the cylinder switching process is realized, the problems of large fluctuation of unit load, high discharge temperature rise and the like in the cylinder switching process are avoided, and the unit operation safety is ensured.

In the first step, a pipeline is led from a steam source equipment interface and is connected to a pipeline in front of a high-pressure cylinder pre-warming adjusting electric door, and a manual or electric isolating door is added to serve as a high-pressure cylinder pre-warming steam source;

a drainage manual door or a pneumatic door is added in front of and behind the isolation door;

adding a manual door or an electric door to the original reheating steam cold section to the high-pressure cylinder back-warming electric door;

and a drainage pipeline and a valve are added in front of and behind the high-discharge check valve.

And according to the actual situation on site, a reasonable steam source is selected for back warming of the high-pressure cylinder. And the steam source parameters are stable, and the requirement of the steam turbine on back warming is met. Leading a pipeline from a steam source equipment interface to be connected to a pipeline in front of a high-pressure cylinder pre-warming adjusting electric door, adding a manual and electric isolating door as a high-pressure cylinder pre-warming steam source, and adding a drainage manual door and a pneumatic door in front of and behind the isolating door; adding a manual door and an electric door to an original reheating steam cold section to a high-pressure cylinder back-warming electric door to be used as a high-pressure cylinder pre-warming standby steam source; the drainage pipeline and the valve are added in front of and behind the high-drainage check valve, so that pipeline vibration caused by unsmooth drainage when the cylinders are switched is eliminated.

The inverted warm logic system comprises a high-pressure cylinder inverted warm automatic input logic judgment module, a warm pipe electric valve automatic adjustment module in communication connection with the high-pressure cylinder inverted warm automatic input logic judgment module, a high-pressure cylinder warm rigid parameter monitoring module in communication connection with the warm pipe electric valve automatic adjustment module, and a high-pressure cylinder warm rigid end logic judgment module in communication connection with the high-pressure cylinder warm rigid parameter monitoring module. And in the second step, the high-pressure bypass regulating valve is automatically switched on, the high-pressure discharge check valve is in a closed state, and the back-to-front pressure difference of the high-pressure discharge check valve is automatically switched on when a negative number is obtained.

The high-pressure cylinder reverse heating automatic input logic: the high-pressure bypass regulating valve is automatically put into operation; the high-discharge check valve instruction is in a closed state; the front-back pressure difference of the high-discharge check valve is negative. Automatic adjustment of the electric heating pipe adjusting valve: and calculating the minimum value of the pressure difference allowance and the temperature allowance before and after the high-discharge check valve to be used as a set value of the real-time temperature rise rate, and then calculating the opening degree of the back-heating regulating valve through pid control. Monitoring parameters of a high-pressure cylinder: the front and rear pressure of the high-discharge check valve is more than or equal to 0, or the high-pressure bypass valve is automatically withdrawn, or the temperature difference of the metal wall of the high-pressure cylinder exceeds the upper limit, or the temperature rising rate of the metal wall of the high-pressure cylinder exceeds a set value; the metal temperature rise rate is controlled to be 1 ℃/min. And (3) ending logic judgment of the high-pressure cylinder warming: the temperature of the metal wall of the high-pressure cylinder is higher than the set value of the back heating.

The positive-warming logic system comprises a high-pressure cylinder positive-warming automatic input logic judgment module, a high-transfer door automatic adjustment module, a high-pressure cylinder positive-warming parameter monitoring module and a high-pressure cylinder positive-warming ending logic judgment module, wherein the high-transfer door automatic adjustment module is in communication connection with the high-pressure cylinder positive-warming automatic input logic judgment module, the high-pressure cylinder positive-warming parameter monitoring module is in communication connection with the high-transfer door automatic adjustment module, and the high-pressure cylinder positive-warming ending logic judgment module is in communication connection with the high-pressure cylinder positive-warming parameter monitoring module. In the third step, the metal temperature of the first stage of the high-pressure inner cylinder is 150-320 ℃, the high-pressure main steam valve MSV is in a closed state, and the #2 main steam valve pre-opening valve is in an open state and is automatically started in a normal heating mode.

And (3) judging the positive heating automatic input logic of the high-pressure cylinder: the high pressure inner cylinder first stage metal temperature is 150-320 ℃ and the high pressure Main Steam Valve (MSV) is in a closed state (main steam for preheating enters the governing valve steam chamber through the pre-opened valve of the #2 main steam valve) and the #2 main steam valve pre-opened valve is in an open state and positive warming has been put into effect.

Automatic adjustment of the high-adjustment door: the PID controller inputs and increases the temperature of the upper wall of the inner cylinder of the high-pressure cylinder and outputs a positive-heating automatic control instruction. And a control instruction output by the PID is input in the automatic warming state, and the high-speed adjusting flow is increased or decreased by a manual button in the manual state. Add high-throttle unlock logic: the temperature difference between the metal walls of the high pressure cylinder and the intermediate pressure cylinder exceeds the limit. At this time, the locking high-pressure regulating door is opened, and the temperature difference between the metal walls of the high-pressure cylinder and the intermediate-pressure cylinder is reduced after the temperature of the metal wall of the intermediate-pressure cylinder rises. High pressure cylinder is warm parameter monitoring module just: the temperature rise rate of the high-pressure cylinder is out of limit, the temperature difference of the inner cylinder of the high-pressure cylinder is out of limit, the rotating speed is reduced, the pressure of the reheated steam is reduced, and the like. And (5) finishing positive warming of the high-pressure cylinder: the temperature of the metal wall of the high-pressure cylinder reaches a positive heating control set value. In the fourth step, the rotating speed of the steam turbine is more than or equal to 3000r/min, the opening degrees of the intermediate regulating valves ICV1 and ICV2 are more than 40%, and the cylinders are switched and automatically put into operation when the load of the unit is within the range of 45-65 MW.

Cylinder switching automatic input conditions: and meanwhile, the cylinders can be switched automatically when the rotating speed is 3000r/min, the opening degrees ICV1 and ICV2 of the intermediate regulating valve are more than 40%, the temperature of the first-stage metal of the high and intermediate pressure cylinders reaches a limit value (300 ℃, the interface can be set), the high and low side pressure reducing valves are switched automatically, the main steam pressure is in a set range, the high regulating valve is in a valve position control state, the intermediate regulating valve is fully opened, and the load of the unit is in a range of 45-65 MW. Cylinder switching completion conditions: the high-pressure bypass reducing valve is fully closed, the low-pressure bypass reducing valve is fully closed, the intermediate pressure cylinder regulating valve is fully opened, the high-discharge check valve is opened, and the front and rear pressure of the valve becomes > 0. Perfecting cylinder switching protection logic: the high-pressure regulating valve opening and high-pressure and low-pressure bypass closing processes are coordinated and automatically controlled, the load is stable in the cylinder switching process, the exhaust temperature of the high-pressure cylinder does not exceed the limit value, and the high-pressure exhaust check valve is stably opened.

In the description of the present invention, it is to be understood that the terms "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used merely for convenience of description and for simplicity of description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, are not to be construed as limiting the present invention. In the description of the present invention, unless otherwise specified and limited, it is to be noted that the terms "mounted," "connected," and "connected" are to be interpreted broadly, and may be, for example, a mechanical connection or an electrical connection, a communication between two elements, a direct connection, or an indirect connection via an intermediate medium, and specific meanings of the terms may be understood by those skilled in the art according to specific situations.

The present invention is not limited to the above preferred embodiments, and any modifications, equivalent substitutions, improvements, etc. within the spirit and principle of the present invention should be included in the protection scope of the present invention.