A Control Method for Emergency Exhaust System of Adaptive Expansion Generator Set Based on Operating Conditions

Abstract

This invention discloses a control method for an emergency exhaust system of an adaptive expander generator set, comprising: acquiring relevant data and sending it to a generator power storage circuit, an emergency exhaust valve opening control circuit, and an emergency exhaust valve closing control circuit; determining the emergency exhaust valve opening control circuit; determining the emergency exhaust valve closing control circuit; and, based on the above determinations, closing all emergency exhaust valves, thereby gradually restoring the generator speed to its rated speed under the control of the intake regulating valve. By controlling the opening and closing of the emergency exhaust valves according to the operating mode of the expander generator set after load shedding and the inlet pressure of each stage of the expander, the method effectively suppresses the rapid increase in generator speed, reduces working fluid waste, significantly reduces the stabilization time of the unit speed, and facilitates rapid unit recovery.

Description

Technical Field

[0001] This invention relates to the technical field of compressed air energy storage, and in particular to a control method for an emergency exhaust system of an adaptive expansion generator set based on operating conditions. Background Technology

[0002] With the large-scale grid connection of distributed renewable energy, large-scale energy storage technology, as an effective means to improve grid stability, has received increasing attention. Compressed air energy storage, as the most promising large-scale long-term energy storage technology, has advantages such as high efficiency, large capacity, long storage time, and relatively low cost. A multi-stage expansion power generation system of a non-combustion-type compressed air energy storage system consists of an expander, generator, heat exchanger, and corresponding pipelines, with a large gas volume within the system. If a system fault occurs during power generation, the generator output circuit breaker will trip, the generator set will shed the electrical load, and the residual compressed air in the system will drive the expansion generator set speed to increase significantly. To prevent equipment damage caused by the generator speed overshooting, an emergency venting system is generally designed. After load shedding, the residual air is discharged by opening each emergency venting valve, preventing the unit from overspeeding.

[0003] Current practices regarding the control of emergency exhaust valves vary. Generally, the status of the generator outlet circuit breaker is monitored. When the generator outlet circuit breaker opens, all emergency exhaust valves are opened, and after a fixed time or after sensing a fixed drop in compressed air pressure, the emergency exhaust valves are closed. Chinese patent application (application number 6201821960475.5) discloses an emergency exhaust system for an expansion generator, in which the emergency exhaust valves open when the generator outlet circuit breaker opens and the intake valve closes; and close only after the generator speed reaches zero and the intake valve closes. All of the above methods have the following shortcomings: they do not consider the two operating conditions of the unit idling after load shedding and operating with auxiliary power after load shedding; the control of the emergency exhaust valves is not precise enough, easily leading to excessive or insufficient exhaust, resulting in a longer time for the generator speed to stabilize or a second speed spike, which is not conducive to the unit's rapid restoration to grid connection. Summary of the Invention

[0004] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0005] In view of the problems existing in the current control method for emergency exhaust system of adaptive expansion generator set based on operating conditions, the present invention is proposed.

[0006] Therefore, the purpose of this invention is to provide a control method for the emergency exhaust system of an adaptive expansion generator set based on operating conditions.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution: acquiring relevant data and sending it into the generator power temporary storage circuit, the emergency exhaust valve opening control circuit, and the emergency exhaust valve closing control circuit;

[0008] The emergency exhaust valve opening control circuit is judged;

[0009] The emergency exhaust valve closure control circuit is judged; and,

[0010] Based on the above judgment, close all emergency exhaust valves and, under the control of the intake regulating valve, gradually restore the generator speed to the rated speed.

[0011] As a preferred embodiment of the emergency exhaust system control method for an adaptive expansion generator set based on operating conditions described in this invention, the generator power Ng under normal operating conditions is obtained and sent to the generator power temporary storage circuit.

[0012] Obtain the current status Bg of the generator outlet circuit breaker and send it to the emergency exhaust valve opening control circuit;

[0013] The current status Bs of the plant load circuit breaker and the measured value P1 of the inlet pressure of the first stage of the expander are obtained, and the current status Bg of the generator outlet circuit breaker are sent to the emergency exhaust valve closing control circuit.

[0014] As a preferred embodiment of the emergency exhaust system control method for an adaptive expansion generator set based on operating conditions described in this invention, wherein: the generator power Ng is continuously measured by a high-precision power transmitter; the current state Bg of the generator outlet circuit breaker is obtained by a generator outlet circuit breaker position sensor; the current state Bs of the plant load circuit breaker is obtained by a plant load circuit breaker position sensor; and the measured value P1 of the inlet pressure of the first stage group of the expander is continuously measured by a high-precision pressure transmitter.

[0015] As a preferred embodiment of the emergency exhaust system control method for an adaptive expansion generator set based on operating conditions described in this invention, the generator power temporary storage circuit receives the generator power Ng and stores it in the temporary storage module for one calculation cycle, and then sends it as the generator power output value Ng-before of the previous calculation cycle to the emergency exhaust valve opening control circuit.

[0016] As a preferred embodiment of the emergency exhaust system control method for the adaptive expansion generator set described in this invention, wherein: if the expansion generator set or the power system malfunctions, the motor output circuit breaker is disconnected, and the expansion generator set is disconnected from the power grid.

[0017] The generator outlet circuit breaker position sensor sends a generator outlet circuit breaker status Bg signal to the emergency exhaust valve opening control circuit and the emergency exhaust valve closing control circuit.

[0018] As a preferred embodiment of the emergency exhaust system control method for an adaptive expansion generator set based on operating conditions described in this invention, the current state Bs of the plant load circuit breaker includes the plant load circuit breaker state Bs being in the open position and the plant load circuit breaker state Bs being in the closed position.

[0019] If the plant load circuit breaker is disconnected, the plant load circuit breaker position sensor will send a signal indicating that the plant load circuit breaker status Bs is in the open position.

[0020] If the plant load circuit breaker is not continuously switched on, the plant load circuit breaker position sensor will send a signal that the plant load circuit breaker status Bs is in the closed position.

[0021] Both signals from the position sensor of the plant load circuit breaker are sent to the emergency exhaust valve opening control circuit.

[0022] As a preferred embodiment of the emergency exhaust system control method for an adaptive expansion generator set based on operating conditions described in this invention, the determination of the emergency exhaust valve opening control loop includes...

[0023] If the generator outlet circuit breaker status Bg is in the open position and the generator power Ng-before ≥ 80% of the generator rated power N0 before the load shedding, and a manual forced command is issued, then all emergency exhaust valves will be opened.

[0024] If the generator outlet circuit breaker status Bg is in the open position and the generator power Ng-before before load shedding is between 80% and 20% of the generator rated power N0, and a manual forced command is issued, then 75% of the emergency exhaust valves from the highest pressure position onwards will be opened.

[0025] As a preferred embodiment of the emergency exhaust system control method for an adaptive expansion generator set based on operating conditions described in this invention, the determination of the emergency exhaust valve closing control loop includes:

[0026] If the generator outlet circuit breaker status Bg is in the open position and the plant load circuit breaker status Bs is in the open position, then it enters the idling mode.

[0027] At this time, if the measured value P1 of the inlet pressure of the first stage group of the expander is less than the set value P of the emergency exhaust valve closing under no-load conditions, K1 Then close all emergency exhaust valves;

[0028] If the generator outlet circuit breaker is in the open position (Bg) and the plant load circuit breaker is in the closed position (Bs), then the system enters the rapid load operation mode.

[0029] At this time, if the measured value P1 of the inlet pressure of the first stage group of the expander is less than the closing value P of the emergency exhaust valve under rapid load conditions, K2 Then close all emergency exhaust valves;

[0030] If a manual command is issued to close the emergency exhaust valve, all emergency exhaust valves will be closed.

[0031] As a preferred embodiment of the emergency exhaust system control method for adaptive expansion generator sets based on operating conditions described in this invention, wherein: after any of the above judgments can close all emergency exhaust valves, a closing command is issued to all emergency exhaust valves.

[0032] As a preferred embodiment of the emergency exhaust system control method for an adaptive expansion generator set based on operating conditions described in this invention, wherein: the idling condition emergency exhaust valve closing setpoint P K1 The calculation formula is as follows:

[0033] P K1 =K1×P 10

[0034] Wherein, K1 is a coefficient, which depends on the closing speed of the emergency exhaust valve and the opening speed of the intake regulating valve. Based on the expander's no-load operating data, the inlet pressure of the first stage of the expander is obtained at the rated value P under no-load operating conditions. 10 ;

[0035] The emergency exhaust valve closing setpoint P under rapid load reduction conditions K2 The calculation formula is as follows:

[0036] P K2 =K2×P 1FCB

[0037] Where K2 is a coefficient that depends on the power N under rapid load reduction conditions. FCB Emergency exhaust valve closing speed and intake regulating valve opening speed;

[0038] This involves calculating the power required to maintain operation of each auxiliary device under rapid load reduction conditions, and summing these figures to obtain the required power N under rapid load reduction conditions. FCB Thus, the rated value P of the first-stage group inlet pressure under rapid load reduction condition is obtained. 1FCB .

[0039] The beneficial effects of this invention are as follows: Based on the working mode of the expander generator set after load shedding and the inlet pressure of each stage of the expander, the opening and closing of the emergency exhaust valve is controlled, thereby effectively suppressing the rapid increase in generator speed, reducing working fluid waste, significantly reducing the stabilization time of the unit speed, and facilitating the rapid recovery of the unit. Attached Figure Description

[0040] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0041] Figure 1 This is a schematic diagram of the connection of a compressed air energy storage expansion power generation system.

[0042] Figure 2 This is a flowchart of the generator power temporary storage circuit described in the emergency exhaust system control method for adaptive expansion generator sets based on operating conditions of the present invention.

[0043] Figure 3 This is a flowchart of the emergency exhaust valve opening control loop described in the emergency exhaust system control method for adaptive expansion generator sets based on the operating conditions of this invention.

[0044] Figure 4 This is a flowchart of the emergency exhaust valve closing control loop described in the emergency exhaust system control method for adaptive expansion generator sets based on the present invention.

[0045] Figure 5 A comparison chart showing the impact of this invention on generator speed when 10MW load is shed and the generator enters idling mode.

[0046] Figure 6 A comparison chart showing the impact of this invention on generator speed when switching to FCB mode to shed 10MW load. Detailed Implementation

[0047] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0048] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0049] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0050] Secondly, the present invention is described in detail with reference to the schematic diagrams. When detailing the embodiments of the present invention, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged, not according to the usual scale. Furthermore, the schematic diagrams are merely examples and should not limit the scope of protection of the present invention. In addition, actual fabrication should include three-dimensional spatial dimensions of length, width, and depth.

[0051] Example 1

[0052] Reference Figures 1-4 A control method for an emergency exhaust system of a condition-adaptive expansion generator set includes:

[0053] Figure 1 In the process, the high-pressure air stored in the air tank (2) enters the first stage heater through the pipeline and is heated by the intake regulating valve. Then it enters the first stage group of the expander to do work. The compressed air after doing work is discharged from the first stage group of the expander, heated by the second stage heater, and enters the second stage group of the expander. This process continues until it is discharged from the last stage group of the expander. When the compressed air enters each stage group of the expander to do work, it drives the expander to rotate. The expander drives the generator to rotate and generate electricity through the shaft. In the event of a system failure, the generator outlet circuit breaker will be disconnected first. Then, the electrical protection device will determine and control whether the plant load circuit breaker is disconnected according to the preset settings. If the plant load circuit breaker remains closed, the generator set will continue to generate electricity. The generated electricity is used to supply the auxiliary equipment in the plant. This is called the fast load reduction condition (FCB). If the plant load circuit breaker is disconnected, the generator set will no longer generate electricity and will enter the idling state. This is called the pure load shedding condition.

[0054] S1: Acquires relevant data and sends it to the generator power temporary storage circuit, the emergency exhaust valve opening control circuit, and the emergency exhaust valve closing control circuit. It should be noted that:

[0055] Obtain the generator power Ng under normal operating conditions and send it to the generator power temporary storage circuit.

[0056] The generator power Ng is obtained by continuous measurement using a high-precision power transmitter.

[0057] Obtain the current status Bg of the generator output circuit breaker and send it to the emergency exhaust valve opening control circuit.

[0058] The current state Bg of the generator outlet circuit breaker is obtained through the generator outlet circuit breaker position sensor.

[0059] Obtain the current status Bs of the plant load circuit breaker and the measured value P1 of the inlet pressure of the first stage of the expander, and send the current status Bg of the generator outlet circuit breaker into the emergency exhaust valve closing control circuit.

[0060] Among them, the current status Bs of the plant load circuit breaker is obtained through the plant load circuit breaker position sensor; the measured value P1 of the inlet pressure of the first stage group of the expander is obtained by continuous measurement through a high-precision pressure transmitter.

[0061] Reference Figure 2 After receiving the generator power Ng, the generator power temporary storage circuit stores one calculation cycle in the temporary storage module, and then sends it as the generator power output value Ng-before of the previous calculation cycle to the emergency exhaust valve opening control circuit.

[0062] If an abnormality occurs in the expansion generator set or the power system, the motor output circuit breaker will disconnect, and the expansion generator set will be disconnected from the power grid.

[0063] At this time, the generator outlet circuit breaker position sensor sends a generator outlet circuit breaker status Bg signal indicating that it is in the open position and sends it to the emergency exhaust valve opening control circuit and the emergency exhaust valve closing control circuit.

[0064] After the generator outlet circuit breaker is disconnected, the electrical protection device (not within the scope of this invention) determines whether to disconnect the plant load circuit breaker.

[0065] Among them, the current state Bs of the plant load circuit breaker includes the plant load circuit breaker state Bs being in the open position and the plant load circuit breaker state Bs being in the closed position.

[0066] If the plant load circuit breaker is disconnected, the plant load circuit breaker position sensor will send a status signal Bs indicating that the plant load circuit breaker is in the open position.

[0067] If the plant load circuit breaker is not continuously switched on and off, the plant load circuit breaker position sensor will send a signal indicating that the plant load circuit breaker status Bs is in the closed position.

[0068] Regardless of whether the plant load circuit breaker is disconnected, the current status Bs signal of the plant load circuit breaker is sent to the emergency exhaust valve opening control circuit.

[0069] S2: Determines the emergency exhaust valve opening control circuit. It should be noted that:

[0070] Reference Figure 3 If the generator outlet circuit breaker status Bg is in the open position and the generator power Ng-before before load shedding is ≥80% of the generator rated power N0, then all emergency exhaust valves are opened.

[0071] If an emergency exhaust valve opening command is manually issued, all emergency exhaust valves will be opened.

[0072] If the generator outlet circuit breaker status Bg is in the open position and the generator power Ng-before before load shedding is between 80% and 20% of the generator rated power N0, then open 75% of the emergency exhaust valves from the highest pressure position.

[0073] If an emergency exhaust valve opening command is manually issued, 75% of the emergency exhaust valves from the highest pressure position onwards will be opened.

[0074] S3: Determines whether the emergency exhaust valve closure control circuit is closed. It should be noted that:

[0075] After the emergency exhaust valve is opened, the generator speed will first rise and then fall, and the measured value of the inlet pressure P1 of the first stage expander will gradually decrease.

[0076] Reference Figure 4 If the generator outlet circuit breaker status Bg is in the open position and the plant load circuit breaker status Bs is in the open position, then the machine enters the idling mode.

[0077] At this time, if the measured value P1 of the inlet pressure of the first stage group of the expander is less than the set value P of the emergency exhaust valve closing under no-load conditions, K1 Then close all emergency exhaust valves;

[0078] Emergency exhaust valve closing setpoint P during idling operation K1 The calculation formula is as follows:

[0079] P K1 =K1×P 10

[0080] Wherein, K1 is a coefficient, which depends on the closing speed of the emergency exhaust valve and the opening speed of the intake regulating valve. Based on the expander's no-load operating data, the inlet pressure of the first stage group of the expander is obtained at the rated value P under no-load operating conditions. 10 ;

[0081] If the generator outlet circuit breaker status Bg is in the open position and the plant service load circuit breaker status Bs is in the closed position, then the system enters the fast load FCB operating condition.

[0082] At this time, if the measured value P1 of the inlet pressure of the first stage group of the expander is less than the set value P of the emergency exhaust valve closing under rapid load conditions... K2 Then close all emergency exhaust valves.

[0083] FCB Emergency Exhaust Valve Closure Setpoint P K2 The calculation formula is as follows:

[0084] P K2 =K2×P1FCB

[0085] Where K2 is a coefficient that depends on the FCB operating power N. FCB Emergency exhaust valve (12-1, ..., 12-i) closing speed and intake regulating valve opening speed;

[0086] Specifically, the power required to maintain operation of each auxiliary device under Fast Load Decrease (FCB) conditions is calculated, and the total power N required under FCB conditions is obtained by summing these figures. FCB Thus, the inlet pressure of the first stage group at the rated value P under FCB operating conditions is obtained. 1FCB .

[0087] If a manual command is issued to close the emergency exhaust valve, all emergency exhaust valves will be closed.

[0088] Any of the above judgments can be used to close all emergency exhaust valves, and then a closing command will be issued to all emergency exhaust valves.

[0089] S4: Based on the above judgment, close all emergency exhaust valves, and under the control of the intake regulating valve, gradually restore the generator speed to the rated speed.

[0090] Example 2

[0091] This embodiment is the second embodiment of the present invention. Unlike the first embodiment, this embodiment provides a verification test of the emergency exhaust system control method based on the adaptive expansion generator set under operating conditions, and verifies and explains the technical effects adopted in this method.

[0092] The steps of this method are as follows:

[0093] Preparations before implementation:

[0094] A1: In the control system according to Figure 2 , Figure 3 , Figure 4 Complete the control logic configuration.

[0095] A2: Actual measurements were conducted under no-load conditions in the compressed air energy storage expansion power generation system, and the inlet pressure of the first stage of the expander was obtained at the rated value P under no-load conditions. 10 It is 0.37 MPa.

[0096] A3: Set the emergency exhaust valve closing value P for idling operation. K1 =K1×P 10 .

[0097] Wherein, K1 is related to the closing speed of the emergency exhaust valves (12-1, ..., 12-i) and the opening speed of the intake regulating valve, and is taken as 1.135; P 10The setpoint P for closing the emergency exhaust valve under idling conditions is 0.37 MPa. K1 The pressure is 0.42 MPa, which is used to fill the emergency exhaust valve shut-off control circuit.

[0098] A4: Calculate the power required to maintain operation of each auxiliary device under Fast Load Decrease (FCB) conditions, and summarize the total power N required under FCB conditions. FCB The rated value P for the first stage group inlet pressure under FCB conditions was obtained by actual measurement under the condition that the unit is connected to the grid and the plant auxiliary load is 1MW. 1FCB The pressure is 3.36 MPa.

[0099] A5: Set the emergency exhaust valve closing value P for FCB operating conditions K2 =K2×P 1FCB ;

[0100] Among them, K2 and FCB operating power N FCB The closing speed of the emergency exhaust valves (12-1, ..., 12-i) is related to the opening speed of the intake regulating valve, and is taken as 1.339; P 1FCB The setpoint P for the emergency exhaust valve closing under FCB operating conditions is 3.36 MPa. K2 The pressure is 4.5 MPa, which is used to close the emergency exhaust valve control circuit.

[0101] After shedding the load, it enters the idling mode:

[0102] B1: The expander generator set is operating normally. Adjust the unit to maintain the power generation at the rated value of 10MW. Use a high-precision power transmitter to continuously measure the generator power Ng and send the signal to the generator power temporary storage circuit. Use the generator outlet circuit breaker position sensor to measure the current status Bg of the generator outlet circuit breaker and send the signal to the emergency exhaust valve opening control circuit and the emergency exhaust valve closing control circuit. Use the plant load circuit breaker position sensor to measure the current status Bs of the plant load circuit breaker and send the signal to the emergency exhaust valve closing control circuit. Use a high-precision pressure transmitter to continuously measure the measured value P1 of the inlet pressure of the first stage group of the expander and send the signal to the emergency exhaust valve closing control circuit.

[0103] B2: After receiving the generator power Ng, the generator power temporary storage circuit stores one calculation cycle in the temporary storage module, and then sends it as the generator power output value Ng-before of the previous calculation cycle to the emergency exhaust valve opening control circuit.

[0104] B3: Inspect and configure the electrical protection devices, setting them to simultaneously disconnect the plant load circuit breaker after the generator outlet circuit breaker is disconnected; simulate a system fault, causing the generator outlet circuit breaker to disconnect, and the generator outlet circuit breaker position sensor to send a "generator outlet circuit breaker status Bg in open position" signal to the emergency exhaust valve opening control circuit and the emergency exhaust valve closing control circuit.

[0105] B4: After the generator outlet circuit breaker is disconnected, the electrical protection device controls the synchronous disconnection of the plant load circuit breaker. The plant load circuit breaker position sensor sends a status signal Bs of the plant load circuit breaker in the open position. The status signal Bs of the plant load circuit breaker is sent to the emergency exhaust valve opening control circuit.

[0106] B5: Judgment is made in the emergency exhaust valve opening control circuit: At this time, the generator outlet circuit breaker status Bg is in the open position, the generator power Ng-before before load shedding is 10MW, which is greater than 80% of the generator rated power N0, and all emergency exhaust valves are opened.

[0107] B6: After the emergency exhaust valve is opened, the generator speed will first rise and then fall, and the measured value of the inlet pressure P1 of the first stage of the expander will gradually decrease.

[0108] Emergency exhaust valve closing control circuit judgment: Because the generator outlet circuit breaker status Bg is in the open position and the plant load circuit breaker status Bs is in the open position, it enters the idling condition; the emergency exhaust valve closing control circuit continues to judge the magnitude of the measured value P1 of the first stage group inlet pressure of the expander. When P1 is less than 0.42MPa, it orders the closure of all emergency exhaust valves.

[0109] B7: After closing all emergency exhaust valves, the generator speed will gradually return to the rated speed under the control of the intake regulating valve.

[0110] After load shedding, the system enters FCB (Full Load Break) mode.

[0111] C1: The expander generator set is operating normally. Adjustments are made to maintain the power generation at the rated value of 10MW. A high-precision power transmitter is used to continuously measure the generator power Ng, and the signal is sent to the generator power temporary storage circuit. The generator outlet circuit breaker position sensor is used to measure the current status Bg of the generator outlet circuit breaker, and the signal is sent to the emergency exhaust valve opening control circuit and the emergency exhaust valve closing control circuit. The plant load circuit breaker position sensor is used to measure the current status Bs of the plant load circuit breaker, and the signal is sent to the emergency exhaust valve closing control circuit. A high-precision pressure transmitter is used to continuously measure the measured value P1 of the inlet pressure of the first stage group of the expander, and the signal is sent to the emergency exhaust valve closing control circuit.

[0112] C2: After receiving the generator power Ng, the generator power temporary storage circuit stores one calculation cycle in the temporary storage module, and then sends it as the generator power output value Ng-before of the previous calculation cycle to the emergency exhaust valve opening control circuit.

[0113] C3: Inspect and configure the electrical protection devices, setting them so that the plant load circuit breaker does not disconnect after the generator outlet circuit breaker is disconnected; in the event of a system fault, the generator outlet circuit breaker will disconnect, and the generator outlet circuit breaker position sensor will send a "generator outlet circuit breaker status Bg is open" signal to the emergency exhaust valve opening control circuit and the emergency exhaust valve closing control circuit.

[0114] C4: After the generator outlet circuit breaker is disconnected, the electrical protection device does not disconnect the plant load circuit breaker. The plant load circuit breaker position sensor sends a "plant load circuit breaker status Bs is in the closed position" signal. The plant load circuit breaker status Bs signal is sent to the emergency exhaust valve opening control circuit.

[0115] C5: Judgment is made in the emergency exhaust valve opening control circuit: At this time, the generator outlet circuit breaker status Bg is in the open position, the generator power Ng-before before load shedding is 10MW, which is greater than 80% of the generator rated power N0, and all emergency exhaust valves are opened.

[0116] C6: After the emergency exhaust valve opens, the generator speed first increases and then decreases, and the measured value of the first-stage expander inlet pressure P1 will gradually decrease. The emergency exhaust valve closing control circuit determines the following: Because the generator outlet circuit breaker status Bg is in the open position and the plant auxiliary load circuit breaker status Bs is in the closed position, the system enters FCB mode; the emergency exhaust valve closing control circuit continues to determine the magnitude of the measured value of the first-stage expander inlet pressure P1. When P1 is less than 4.5 MPa, it orders the closure of all emergency exhaust valves.

[0117] C7: After closing all emergency exhaust valves, the generator speed will gradually return to the rated speed under the control of the intake regulating valve.

[0118] Using the method of this invention, when the generator is idling with a 10MW load, the maximum speed of the generator can be controlled to below 3051 r / min, which is 200 r / min lower than the maximum speed without this invention; when the generator is idling with a 10MW load, the maximum speed of the generator can be controlled to below 3054 r / min, which is 36 r / min lower than the maximum speed without this invention; the effect of this invention on speed suppression is very obvious.

[0119] Using the method of this invention, when the generator speed stabilizes in the idling condition after shedding 10MW of load, the stabilization time is about 50 seconds, which is 450 seconds less than the stabilization time without this invention; when the generator speed stabilizes in the FCB condition after shedding 10MW of load, the stabilization time is about 140 seconds, which is 260 seconds less than the stabilization time without this invention; the effect of this invention on rapid speed stabilization and rapid unit recovery is very obvious.

[0120] The comparison results are as follows Figure 5 , Figure 6 As shown.

[0121] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A control method for an emergency exhaust system of an adaptive expansion generator set based on operating conditions, characterized in that: include, Acquire relevant data and send it to the generator power temporary storage circuit, the emergency exhaust valve opening control circuit, and the emergency exhaust valve closing control circuit; The emergency exhaust valve opening control circuit is judged; The emergency exhaust valve closure control circuit is judged; and, Based on the above judgment, close all emergency exhaust valves, and under the control of the intake regulating valve, gradually restore the generator speed to the rated speed; The determination of the emergency exhaust valve opening control circuit includes, If the generator outlet circuit breaker status Bg is in the open position and the generator power Ng-before ≥ 80% of the generator rated power N0, and a manual forced command is issued, then all emergency exhaust valves will be opened. If the generator outlet circuit breaker status Bg is in the open position and the generator power Ng-before before load shedding is between 80% of the generator rated power N0 and 20% of the generator rated power N0, and is manually forced to be issued, then 75% of the emergency exhaust valves from the highest pressure position onwards will be opened. The determination of the emergency exhaust valve closure control circuit includes, If the generator outlet circuit breaker status Bg is in the open position and the plant load circuit breaker status Bs is in the open position, then it enters the idling mode. At this time, if the measured value of the inlet pressure of the first stage group of the expander is... P 1. Less than the emergency exhaust valve closing setpoint under idling conditions P K1 Then close all emergency exhaust valves; If the generator outlet circuit breaker is in the open position (Bg) and the plant load circuit breaker is in the closed position (Bs), then the system enters the rapid load operation mode. At this time, if the measured value of the inlet pressure of the first stage group of the expander is... P 1. Emergency exhaust valve closing setpoint under rapid load reduction conditions P K2 Then close all emergency exhaust valves; If a manual command is issued to close the emergency exhaust valve, all emergency exhaust valves will be closed.

2. The emergency exhaust system control method for an adaptive expansion generator set as described in claim 1, characterized in that: Obtain generator power under normal operating conditions N g, and sent to the generator power temporary storage circuit; Obtain the current status Bg of the generator outlet circuit breaker and send it to the emergency exhaust valve opening control circuit; Obtain the current status Bs of the plant load circuit breaker and the measured value of the inlet pressure of the first stage of the expander. P 1. The current state Bg of the generator outlet circuit breaker is sent to the emergency exhaust valve closing control circuit.

3. The emergency exhaust system control method for an adaptive expansion generator set as described in claim 2, characterized in that: The generator power N g is continuously measured by a high-precision power transmitter; the current state Bg of the generator outlet circuit breaker is obtained by a generator outlet circuit breaker position sensor; the current state Bs of the plant service load circuit breaker is obtained by a plant service load circuit breaker position sensor; and the measured value of the inlet pressure of the first stage of the expander is also measured. P 1. The data is obtained through continuous measurement using a high-precision pressure transmitter.

4. The emergency exhaust system control method for an adaptive expansion generator set as described in claim 2, characterized in that: After receiving the generator power Ng, the generator power temporary storage circuit stores one calculation cycle in the temporary storage module, and then sends it as the generator power output value Ng-before of the previous calculation cycle to the emergency exhaust valve opening control circuit.

5. The emergency exhaust system control method for an adaptive expansion generator set as described in claim 3, characterized in that: If the expansion generator set or the power system malfunctions, the motor output circuit breaker will trip, and the expansion generator set will be disconnected from the power grid. The generator outlet circuit breaker position sensor sends a generator outlet circuit breaker status Bg signal to the emergency exhaust valve opening control circuit and the emergency exhaust valve closing control circuit.

6. The emergency exhaust system control method for an adaptive expansion generator set as described in claim 3, characterized in that: The current state Bs of the plant load circuit breaker includes the plant load circuit breaker state Bs being in the open position and the plant load circuit breaker state Bs being in the closed position. If the plant load circuit breaker is disconnected, the plant load circuit breaker position sensor will send a signal indicating that the plant load circuit breaker status Bs is in the open position. If the plant load circuit breaker is not disconnected, the plant load circuit breaker position sensor will send a signal that the plant load circuit breaker status Bs is in the closed position. Both signals from the position sensor of the plant load circuit breaker are sent to the emergency exhaust valve opening control circuit.

7. The emergency exhaust system control method for an adaptive expansion generator set as described in claim 1, characterized in that: Any of the above judgments can be used to close all emergency exhaust valves, and then a closing command will be issued to all emergency exhaust valves.

8. The emergency exhaust system control method for an adaptive expansion generator set as described in claim 1, characterized in that: The idling condition emergency exhaust valve closing set value P K1 The calculation formula is as follows: P K1 = K 1× P 10 in, K 1 is a coefficient, which depends on the closing speed of the emergency exhaust valve and the opening speed of the intake regulating valve. Based on the expander's no-load operating data, the inlet pressure of the first stage of the expander is obtained at the rated value P under no-load operating conditions. 10 ; The emergency exhaust valve closing setpoint under rapid load reduction conditions P K2 The calculation formula is as follows: P K2 = K 2× P 1FCB in, K 2 is a coefficient that depends on the power output during rapid load reduction. N FCB Emergency exhaust valve closing speed and intake regulating valve opening speed; This involves calculating the power required to maintain operation of each auxiliary device under rapid load reduction conditions, and summing these figures to obtain the total power required under these conditions. N FCB Thus, the rated value of the inlet pressure of the first stage group under rapid load reduction condition is obtained. P 1FCB .

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