Thermal power generating unit device with adjustable steam admission amount of steam turbine and load response control method of thermal power generating unit device

Abstract

The invention discloses a thermal power generating unit device capable of changing steam admission amount of a steam turbine, which comprises the steam turbine, the steam turbine is respectively communicated with three heaters through three pipelines, and each pipeline is respectively provided with a steam extraction check valve, a steam extraction regulating valve and a steam extraction electric valve; the system further comprises a control program, and the control program is connected with the steam extraction check valve, the steam extraction adjusting valve and the steam extraction electric valve. The invention further discloses a load response control method based on change of the steam admission amount of the steam turbine. According to the thermal power generating unit device with the adjustable steam admission amount of the steam turbine, the load change rate of the unit is increased, so that the rapid load change requirement of a power grid is met, and the problem that boiler combustion of a traditional thermal power generating unit is difficult to meet the rapid response requirement of the power grid is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of thermal power generation, relates to a thermal power unit device with adjustable steam inlet amount of a steam turbine, and also relates to the load response control method based on changing the steam inlet amount of the steam turbine. Background Art

[0002] In recent years, with the rapid development of new clean energy such as photovoltaic and wind power, the country has put forward new requirements for the support structure and dispatching operation of traditional power grids in order to promote the consumption of clean energy. Due to the structural characteristics of new clean energy, traditional thermal power not only needs to meet the requirements of deep peak regulation of the power grid, but also needs to meet a higher load response rate. At the same time, the country has issued relevant plans to put forward clear requirements for the low-carbon transformation of coal-fired power, deep regulation, start-stop peak regulation, fast regulation, and wide-load efficient operation.

[0003] Since traditional thermal power units convert chemical energy into thermal energy by transporting coal powder into the furnace for combustion, and heat the steam-water pipe through the heat exchange surface to generate steam to drive the steam turbine to drive the generator to do work, and finally generate electricity, this process involves multiple energy conversions, so there is a certain lag, which is not conducive to the power grid's requirements for rapid load changes for the new generation of coal-fired power units.

[0004] Based on the above, traditional thermal power should not only adapt to deep peak regulation, but also respond quickly to the load change requirements of the power grid. Due to the hysteresis characteristics of the boiler combustion of traditional thermal power units, it is difficult to meet the rapid response and changes of the power grid load without the assistance of auxiliary systems such as external energy storage. Summary of the invention

[0005] The purpose of the present invention is to provide a thermal power unit device with adjustable turbine steam inlet, so as to improve the load change rate of the unit, thereby meeting the rapid load change requirements of the power grid and solving the problem that the boiler combustion of traditional thermal power units is difficult to meet the rapid response of the power grid.

[0006] A second object of the present invention is to provide a load response control method based on changing the steam inlet amount of a steam turbine.

[0007] The first technical solution adopted by the present invention is a thermal power unit device with adjustable steam inlet of a steam turbine, comprising a steam turbine, wherein the steam turbine is connected to three heaters through three pipelines respectively, and each pipeline is provided with a steam extraction check valve, a steam extraction regulating valve and a steam extraction electric valve; It also includes a control program, which is respectively connected with the steam extraction check valve, the steam extraction regulating valve and the steam extraction electric valve.

[0008] The present invention is also characterized in that: The three pipelines are a first-stage steam extraction pipeline, a second-stage steam extraction pipeline and a third-stage steam extraction pipeline. The first-stage steam extraction pipeline is provided with a first-stage steam extraction check valve, a first-stage steam extraction regulating valve and a first-stage steam extraction electric valve in sequence from the steam turbine to the heater. The second-stage steam extraction pipeline is provided with a second-stage steam extraction check valve, a second-stage steam extraction regulating valve and a second-stage steam extraction electric valve in sequence from the steam turbine to the heater. The third-stage steam extraction pipeline is provided with a third-stage steam extraction check valve, a third-stage steam extraction regulating valve and a third-stage steam extraction electric valve in sequence from the steam turbine to the heater.

[0009] The models of the first stage steam extraction check valve, the second stage steam extraction check valve and the third stage steam extraction check valve are consistent; the models of the first stage steam extraction regulating valve, the second stage steam extraction regulating valve and the third stage steam extraction regulating valve are consistent; the models of the first stage steam extraction electric valve, the second stage steam extraction electric valve and the third stage steam extraction electric valve are consistent.

[0010] The steam turbine is connected to a plurality of heaters through a plurality of pipelines, and each pipeline is provided with a steam extraction check valve, a steam extraction regulating valve and a steam extraction electric valve.

[0011] The second technical solution adopted by the present invention is a load response control method based on changing the steam inlet amount of the steam turbine, using the above-mentioned thermal power unit device with adjustable steam inlet amount of the steam turbine, and the specific method is as follows: Normal operation process: When the load of the unit's operating components is not adjusted quickly, the heat recovery system switches are fully open to maintain normal operation and do not participate in regulation; Load response process: When the unit receives the load increase command from the power grid AGC, the regulating valve is adjusted. Under the condition that the total steam inlet volume remains unchanged, the amount of steam used for power generation in the turbine increases, and the unit load increase rate is rapidly improved to meet the power grid AGC requirements. Recovery process: When the actual load of the unit reaches the grid AGC target load, the steam extraction capacity of each steam extraction pipeline of the heat recovery system is gradually restored by controlling the steam extraction pipeline regulating valve.

[0012] The present invention is also characterized in that: During normal operation, when the load is not adjusted quickly during unit operation, the steam extraction check valves, steam extraction regulating valves and steam extraction electric valves on the first, second and third steam extraction pipelines in the unit's steam extraction heat recovery system remain fully open, and the heat recovery system maintains normal operation and does not participate in regulation.

[0013] During the load response process, when the unit receives the grid AGC load increase command, while the turbine responds to normal regulation, the regulating valves of the first, second and third extraction pipes of the heat recovery system are quickly adjusted to reduce the amount of steam extraction entering the heat recovery system from the turbine. At the same time, while the total steam inlet volume remains unchanged, the amount of steam in the turbine used for power generation increases, and the unit load increase rate is rapidly improved to meet the grid AGC requirements.

[0014] During the recovery process, when the actual load of the unit reaches the grid AGC target load, due to the lag of boiler combustion, the unit load is over-adjusted or the steam parameters exceed the specified value requirements. At this time, the control system controls the steam extraction pipeline regulating valve to gradually restore the steam extraction volume of the first, second and third steam extraction pipelines of the heat recovery system. The steam extraction volume entering the heat recovery system in the turbine increases. At the same time, when the total steam inlet volume remains unchanged, the amount of steam used for power generation in the turbine decreases.

[0015] The beneficial effects of the present invention are: The thermal power unit device with adjustable steam inlet of the steam turbine of the present invention changes the first, second and third stage steam extraction of the thermal power unit into an adjustable steam extraction mode, and adds adjustable regulating valves on the first stage steam extraction pipeline, the second stage steam extraction pipeline and the third stage steam extraction pipeline. When the power grid needs to increase the load quickly, the opening of the first stage steam extraction regulating valve, the second stage steam extraction regulating valve and the third stage steam extraction regulating valve is quickly changed to reduce the steam extraction amount from the steam turbine to the heat recovery system, increase the steam amount in the steam turbine for power generation, and improve the load rate of the unit; by adopting the method of the present invention, the steam inlet of the steam turbine is quickly changed in a short time, thereby responding to the load change requirement of the power grid and alleviating the problem of boiler combustion lag. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the structure of a thermal power unit with adjustable steam inlet amount of a steam turbine according to the present invention; Figure 2 The invention discloses a control flow chart of a thermal power unit with adjustable steam inlet amount of a steam turbine. DETAILED DESCRIPTION

[0017] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0018] The invention provides a thermal power unit with adjustable steam inlet of a steam turbine, such as Figure 1 As shown, it includes a steam turbine, which is connected to three heaters through three pipes, each of which is provided with a steam extraction check valve, a steam extraction regulating valve and a steam extraction electric valve; specifically, the three pipes are a first-stage steam extraction pipe, a second-stage steam extraction pipe and a third-stage steam extraction pipe, respectively. The first-stage steam extraction pipe is provided with a first-stage steam extraction check valve, a first-stage steam extraction regulating valve and a first-stage steam extraction electric valve in sequence along the direction from the steam turbine to the heater, the second-stage steam extraction pipe is provided with a second-stage steam extraction check valve, a second-stage steam extraction regulating valve and a second-stage steam extraction electric valve in sequence along the direction from the steam turbine to the heater, and the third-stage steam extraction pipe is provided with a third-stage steam extraction check valve, a third-stage steam extraction regulating valve and a third-stage steam extraction electric valve in sequence along the direction from the steam turbine to the heater.

[0019] The models of the first stage steam extraction check valve, the second stage steam extraction check valve and the third stage steam extraction check valve are consistent; the models of the first stage steam extraction regulating valve, the second stage steam extraction regulating valve and the third stage steam extraction regulating valve are consistent; the models of the first stage steam extraction electric valve, the second stage steam extraction electric valve and the third stage steam extraction electric valve are consistent.

[0020] The steam turbine can also be connected to a plurality of heaters through a plurality of pipelines, and each pipeline is provided with a steam extraction check valve, a steam extraction regulating valve and a steam extraction electric valve.

[0021] It also includes a control program, which is connected to the steam extraction check valve, the steam extraction regulating valve and the steam extraction electric valve. The control program structure is as follows: Figure 2 shown.

[0022] The load response control method based on changing the steam inlet amount of the steam turbine is as follows: During normal operation: During the operation of the unit, when the load is not adjusted quickly, the steam extraction check valve, steam extraction regulating valve and steam extraction electric valve on the first, second and third steam extraction pipelines in the unit's steam extraction heat recovery system are kept in full open state, and the heat recovery system maintains normal operation and does not participate in the adjustment; Load response process: When the unit receives the load increase command from the power grid AGC, while the turbine is responding to the conventional regulation, the regulating valves of the first, second and third extraction pipelines of the heat recovery system are adjusted quickly to reduce the amount of steam extraction from the turbine into the heat recovery system. At the same time, while the total steam intake remains unchanged, the amount of steam used for power generation in the turbine increases, and the unit load increase rate is rapidly increased to meet the power grid AGC requirements; Recovery process: When the actual load of the unit reaches the AGC target load of the power grid, due to the lag of boiler combustion, the unit load is over-adjusted or the steam parameters exceed the specified value requirements. At this time, the control system controls the steam extraction pipeline regulating valve to gradually restore the steam extraction volume of the first, second and third steam extraction pipelines of the heat recovery system. The steam extraction volume entering the heat recovery system in the turbine increases. At the same time, when the total steam inlet volume remains unchanged, the amount of steam used for power generation in the turbine decreases.

[0023] In order to reduce the cold end exhaust loss and improve the cycle efficiency of the thermal process, a part of the steam entering the steam turbine is extracted through the steam extraction pipeline for heating the feed water in the heat recovery system, and the rest of the steam is used for power generation. Conventional steam extraction pipelines are controlled by steam extraction check valves and steam extraction electric valves, which are non-adjustable control methods. By adding an adjustable regulating valve to the conventional steam extraction pipeline, the amount of steam entering the heat recovery system can be adjusted and controlled. When the unit needs to increase the load quickly, the opening of the regulating valve is adjusted to reduce the amount of steam entering the heat recovery system, increase the amount of steam used for power generation, and thus quickly increase the load rate of the unit.

[0024] Example 1 Thermal power unit device that can change the steam inlet of the turbine, such as Figure 1 As shown, it includes a steam turbine, and the steam turbine is connected to three heaters through three pipelines, and each pipeline is provided with a steam extraction check valve, a steam extraction regulating valve and a steam extraction electric valve; It also includes a control program, which is respectively connected with the steam extraction check valve, the steam extraction regulating valve and the steam extraction electric valve.

[0025] Example 2 Thermal power unit device that can change the steam inlet of the turbine, such as Figure 1 As shown, it includes a steam turbine, which is connected to three heaters through three pipes, each of which is provided with a steam extraction check valve, a steam extraction regulating valve and a steam extraction electric valve; specifically, the three pipes are a first-stage steam extraction pipe, a second-stage steam extraction pipe and a third-stage steam extraction pipe, respectively. The first-stage steam extraction pipe is provided with a first-stage steam extraction check valve, a first-stage steam extraction regulating valve and a first-stage steam extraction electric valve in sequence along the direction from the steam turbine to the heater, the second-stage steam extraction pipe is provided with a second-stage steam extraction check valve, a second-stage steam extraction regulating valve and a second-stage steam extraction electric valve in sequence along the direction from the steam turbine to the heater, and the third-stage steam extraction pipe is provided with a third-stage steam extraction check valve, a third-stage steam extraction regulating valve and a third-stage steam extraction electric valve in sequence along the direction from the steam turbine to the heater.

[0026] It also includes a control program, which is respectively connected with the steam extraction check valve, the steam extraction regulating valve and the steam extraction electric valve.

[0027] Example 3 The load response control method based on changing the steam inlet amount of the steam turbine is as follows: Normal operation process: When the load of the unit's operating components is not adjusted quickly, the heat recovery system switches are fully open to maintain normal operation and do not participate in regulation; Load response process: When the unit receives the load increase command from the power grid AGC, the regulating valve is adjusted. Under the condition that the total steam inlet volume remains unchanged, the amount of steam used for power generation in the turbine increases, and the unit load increase rate is rapidly improved to meet the power grid AGC requirements. Recovery process: When the actual load of the unit reaches the grid AGC target load, the steam extraction capacity of each steam extraction pipeline of the heat recovery system is gradually restored by controlling the steam extraction pipeline regulating valve.

[0028] Example 4 The load response control method based on changing the steam inlet amount of the steam turbine is as follows: Normal operation process: When the load of the unit's operating components is not adjusted quickly, the heat recovery system switches are fully open to maintain normal operation and do not participate in regulation; Specifically: during the operation of the unit, when the load is not adjusted quickly, the steam extraction check valve, steam extraction regulating valve and steam extraction electric valve on the first, second and third steam extraction pipelines in the unit's steam extraction heat recovery system are kept in full open state, and the heat recovery system maintains normal operation and does not participate in the adjustment; Load response process: When the unit receives the load increase command from the power grid AGC, the regulating valve is adjusted. Under the condition that the total steam inlet volume remains unchanged, the amount of steam used for power generation in the turbine increases, and the unit load increase rate is rapidly improved to meet the power grid AGC requirements. Recovery process: When the actual load of the unit reaches the grid AGC target load, the steam extraction capacity of each steam extraction pipeline of the heat recovery system is gradually restored by controlling the steam extraction pipeline regulating valve.

[0029] Example 5 The load response control method based on changing the steam inlet amount of the steam turbine is as follows: Normal operation process: When the load of the unit's operating components is not adjusted quickly, the heat recovery system switches are fully open to maintain normal operation and do not participate in regulation; Load response process: When the unit receives the load increase command from the power grid AGC, the regulating valve is adjusted. Under the condition that the total steam inlet volume remains unchanged, the amount of steam used for power generation in the turbine increases, and the unit load increase rate is rapidly improved to meet the power grid AGC requirements. Specifically, when the unit receives the load-increasing instruction from the AGC of the power grid, while the turbine is responding to the conventional regulation, the regulating valves of the first, second and third extraction pipelines of the heat recovery system are adjusted quickly to reduce the amount of steam extraction entering the heat recovery system from the turbine. At the same time, when the total steam inlet volume remains unchanged, the amount of steam used for power generation in the turbine increases, and the load-increasing rate of the unit is rapidly increased to meet the AGC requirements of the power grid. Recovery process: When the actual load of the unit reaches the grid AGC target load, the steam extraction capacity of each steam extraction pipeline of the heat recovery system is gradually restored by controlling the steam extraction pipeline regulating valve.

[0030] Example 6 The load response control method based on changing the steam inlet amount of the steam turbine is as follows: Normal operation process: When the load of the unit's operating components is not adjusted quickly, the heat recovery system switches are fully open to maintain normal operation and do not participate in regulation; Load response process: When the unit receives the load increase command from the power grid AGC, the regulating valve is adjusted. Under the condition that the total steam inlet volume remains unchanged, the amount of steam used for power generation in the turbine increases, and the unit load increase rate is rapidly improved to meet the power grid AGC requirements. Recovery process: When the actual load of the unit reaches the grid AGC target load, the steam extraction capacity of each steam extraction pipeline of the heat recovery system is gradually restored by controlling the steam extraction pipeline regulating valve.

[0031] Specifically: when the actual load of the unit reaches the AGC target load of the power grid, due to the lag of boiler combustion, the unit load is over-adjusted or the steam parameters exceed the specified value requirements. At this time, the control system controls the steam extraction pipeline regulating valve to gradually restore the steam extraction volume of the first, second and third steam extraction pipelines of the heat recovery system. The steam extraction volume entering the heat recovery system in the turbine increases. At the same time, when the total steam inlet volume remains unchanged, the amount of steam used for power generation in the turbine decreases.

Claims

1. A thermal power unit with adjustable steam inlet of a steam turbine, characterized in that: It comprises a steam turbine, wherein the steam turbine is connected to three heaters through three pipelines respectively, and each pipeline is provided with a steam extraction check valve, a steam extraction regulating valve and a steam extraction electric valve; It also includes a control program, which is connected to the steam extraction check valve, the steam extraction regulating valve and the steam extraction electric valve respectively.

2. The thermal power generation unit with adjustable steam turbine inlet according to claim 1, characterized in that: The three pipelines are respectively a first-stage steam extraction pipeline, a second-stage steam extraction pipeline and a third-stage steam extraction pipeline. The first-stage steam extraction pipeline is provided with a first-stage steam extraction check valve, a first-stage steam extraction regulating valve and a first-stage steam extraction electric valve in sequence from the steam turbine to the heater. The second-stage steam extraction pipeline is provided with a second-stage steam extraction check valve, a second-stage steam extraction regulating valve and a second-stage steam extraction electric valve in sequence from the steam turbine to the heater. The three-stage steam extraction pipeline is provided with a three-stage steam extraction check valve, a three-stage steam extraction regulating valve and a three-stage steam extraction electric valve in sequence from the steam turbine to the heater.

3. The thermal power generation unit with adjustable steam turbine inlet according to claim 1, characterized in that: The first-stage steam extraction check valve, the second-stage steam extraction check valve and the third-stage steam extraction check valve are of the same model; the first-stage steam extraction regulating valve, the second-stage steam extraction regulating valve and the third-stage steam extraction regulating valve are of the same model; the first-stage steam extraction electric valve, the second-stage steam extraction electric valve and the third-stage steam extraction electric valve are of the same model.

4. The thermal power generation unit with adjustable steam turbine inlet according to claim 1, characterized in that: The steam turbine is connected to a plurality of heaters through a plurality of pipelines, and each of the pipelines is provided with a steam extraction check valve, a steam extraction regulating valve and a steam extraction electric valve.

5. A load response control method based on changing the steam inlet amount of a steam turbine, characterized in that: Using the thermal power unit device with adjustable steam inlet of the steam turbine as claimed in any one of claims 1 to 4, the specific method is as follows: Normal operation process: When the load of the unit's operating components is not adjusted quickly, the heat recovery system switches are fully open to maintain normal operation and do not participate in regulation; Load response process: When the unit receives the load increase command from the power grid AGC, the regulating valve is adjusted. Under the condition that the total steam inlet volume remains unchanged, the amount of steam used for power generation in the turbine increases, and the unit load increase rate is rapidly improved to meet the power grid AGC requirements. Recovery process: When the actual load of the unit reaches the grid AGC target load, the steam extraction capacity of each steam extraction pipeline of the heat recovery system is gradually restored by controlling the steam extraction pipeline regulating valve.

6. The load response control method based on changing the steam inlet amount of the steam turbine according to claim 5, characterized in that: During normal operation, when the load is not adjusted quickly during unit operation, the steam extraction check valves, steam extraction regulating valves and steam extraction electric valves on the first, second and third steam extraction pipelines in the unit's steam extraction heat recovery system remain fully open, and the heat recovery system maintains normal operation and does not participate in regulation.

7. The load response control method based on changing the steam inlet amount of the steam turbine according to claim 5, characterized in that: During the load response process, when the unit receives the grid AGC load increase command, while the turbine responds to normal regulation, the regulating valves of the first, second and third extraction pipes of the heat recovery system are quickly adjusted to reduce the amount of steam extraction entering the heat recovery system from the turbine. At the same time, while the total steam inlet volume remains unchanged, the amount of steam in the turbine used for power generation increases, and the unit load increase rate is rapidly improved to meet the grid AGC requirements.

8. The load response control method based on changing the steam inlet amount of the steam turbine according to claim 5, characterized in that: During the recovery process, when the actual load of the unit reaches the grid AGC target load, due to the lag of boiler combustion, the unit load is over-adjusted or the steam parameters exceed the specified value requirements. At this time, the control system controls the steam extraction pipeline regulating valve to gradually restore the steam extraction volume of the first, second and third steam extraction pipelines of the heat recovery system. The steam extraction volume entering the heat recovery system in the turbine increases. At the same time, when the total steam inlet volume remains unchanged, the amount of steam used for power generation in the turbine decreases.

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