[0030] The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments. The following description is only for demonstration and explanation, and does not limit the present invention in any form.
[0031] In order to realize the safety and economy of the operation of the feed pump steam turbine under the premise of the heating period and the non-heating period thermal process, the heating period (that is, the high back pressure working condition) uses cold and then as the steam source of the small unit, and the non-heating period (I.e. pure condensing condition) use four-pump as the steam source of the small engine, such as figure 1 As shown, the operation method of this kind of feed pump steam turbine suitable for heating and pure condensing dual mode includes the following steps: S1, replacing the rotor and cylinder of the small steam turbine of the existing electric power unit to meet both high back pressure and pure condensing The operating requirements of the feed pump steam turbine of the electric power unit under working conditions; S2, to control the small steam turbine under high back pressure conditions, add a separate manual operator to the pipeline valve again, and remove the low pressure regulating valve to open the pipeline valve The logic of S3, the auxiliary steam source is used during the impulse rotation of the small steam turbine; S4, the cold re-steam source is only used for the small steam turbine under high back pressure operation conditions.
[0032] Among them, in step S3, the auxiliary steam source is used during the impulse rotation of the small steam turbine. When the power unit load is brought to the cold and the pressure meets the requirements, the operator manually switches the small steam turbine gas source. The load band requirement of the electric power unit is ±70MW, and it is avoided that the load is too high and the cold pressure is too high, which makes it inconvenient to control the speed of the small steam turbine when the air source is switched. The operation of the operator to manually switch the gas source of the small steam turbine is to manually open the pipeline valve on the DCS distributed control system and close the auxiliary steam manual valve on the spot.
[0033] In addition, in step S4, the small steam turbine is simply used cold re-steam source under high back pressure operating conditions, and the four-extraction and auxiliary steam source are isolated. After the pipeline valve is fully opened or opened to a certain fixed opening, The speed of the small steam turbine is still controlled by the main regulating valve of the small steam turbine.
[0034] In the implementation, the control method of the feed pump steam turbine suitable for heating and pure condensing dual mode is adopted. When the power unit is started, the pressure changes greatly with the high cooling load during the start-up stage, and the auxiliary steam is used as the impulse steam of the small steam turbine. Power source, and the two small steam turbines will be rushed and speeded up to 2800rpm for standby before the power unit starts rushing. The pressure of the auxiliary steam source is stable, which is convenient for better speed control when the small steam turbine is running and speeding up.
[0035] In the implementation, using this kind of control method suitable for heating and pure condensing dual-mode feedwater pump steam turbines, when the high back pressure heating unit load reaches 70MW, it should be stable for a period of time, and the steam source of two small steam turbines Switch jobs. At this time, the cold re-pressure is close to the auxiliary steam pressure at about 0.85MPa. When the steam source is switched, the disturbance to the speed of the small steam turbine is small.
[0036] In the implementation, using this control method suitable for the heating and pure condensing dual-mode feedwater pump turbine, the switching operation of the steam source of the small steam turbine should be carried out in the standby state of 2800rpm. At this time, the unit load is 70MW, and the electric pump To maintain the water level of the steam drum, the outlet electric doors of the two small steam turbines were fully closed. Rotational disturbance may occur when the steam source of a small steam turbine is switched, so that it does not affect the drum water level control.
[0037] In the implementation, adopt this kind of control method suitable for the heating and pure condensing dual-mode feedwater pump steam turbine. When operating under high back pressure heating conditions, the pipeline valve is controlled at a certain opening to ensure that the main steam turbine Before adjusting the pressure <1.8MPa. In addition, it can control the opening of the main control valve of a small steam turbine within the optimal range of 45% to 70% of the adjustment characteristics. When the steam source pressure behind the pipeline valve is insufficient and the opening of the main control valve of the small steam turbine is high, the large pipeline can be opened slowly The valve makes the small steam turbine still controlled by the main regulating valve to stabilize the speed and automatically reduce the opening of the main regulating valve to ensure the stable output of the small steam turbine. When the steam source pressure behind the pipeline valve is too high and the opening of the main control valve of the small steam turbine is low, the small pipeline valve can be manually closed slowly, the main control valve controls the speed and the valve opening is automatically increased to ensure the stable output of the small steam turbine.
[0038] The control system adopts this kind of control method for the control method of the feed water pump steam turbine in the dual mode of heating and pure condensing for power plant equipment. The control system includes a small steam turbine gas supply control system and a small steam turbine regulation control system. The system can be used for heating and The working condition switching and smooth operation of the feed pump steam turbine in the pure condensate dual mode.
[0039] Among them, the small steam turbine gas supply control system includes a four-stage extraction system, an auxiliary steam source system, and a cold recommissioned steam source system. The four-stage extraction system, an auxiliary steam source system, and a cold recommissioned steam source system are connected to the supply through pipelines and valves. Water pump turbine connection, used for system adjustment when working conditions are switched. The four-stage steam extraction system includes flow measurement device, steam inlet check valve, steam inlet electric valve, manual steam inlet valve, quick-closing valve, drain valve, condenser, flow measurement device, steam inlet check valve, and steam inlet electric valve Valves, manual steam inlet valves, quick-closing valves, drain valves, and condensers are connected by pipelines to adjust the system pressure under pure condensing conditions. The auxiliary steam source system includes the incoming steam manual valve, the front and rear drain valves, the regulating valve, the incoming steam manual valve, the front and rear drain valves, and the regulating valve are connected by pipelines to regulate the heating operation of the system under high-back conditions. The cold recommission steam source system includes steam inlet valve, cold resupply small machine trap valve, cold resupply small machine check valve, high-pressure oil motive, pipeline valve rear trap valve, inlet steam valve, cold resupply small machine trap, cold Then supply the small machine check valve, high-pressure oil motor, and pipeline valve to connect the drain valve through the pipeline to control and adjust the steam source exchange operation. Small steam turbine regulating and control system includes working air source system, debugging steam source system, standby steam source system, pipeline valve, damper, working air source system, debugging steam source system, standby steam source system, pipeline valve, damper through pipeline, The control valve and system monitoring operation device are connected with the feedwater pump steam turbine to ensure the normal operation of the system. The system monitoring and operating device includes a tachometer, display screen, keyboard, and console. The tachometer, display screen, keyboard, and console are connected to the water pump steam turbine and the small steam turbine adjustment control system through cables. In addition, the control valves also include quick-closing valves, emergency shutoff valves, and amplifiers.
[0040] Such as figure 2 As shown, in the implementation, after the improved design of the small steam turbine feedwater pump, due to the increase in the power of the feedwater pump, the small steam turbine uses the cold recommissioned steam source to drive during high back pressure operation, resulting in changes in steam pressure intensity. The flow and pressure are controlled beforehand to facilitate the safe and stable operation of the small steam turbine, while ensuring the convenient operation of the small steam turbine switching operation under the two working conditions of pure condensation and high back pressure, and the design of the small steam turbine gas supply control system, the implementation process is as follows :
[0041] (1) When the system is operating in pure condensing conditions, the four-stage extraction steam system is used for incoming steam, passes through the flow measuring device, the steam inlet check valve, and the steam inlet electric valve, enters the quick-closing valve, and then enters the A and B small valves respectively. Machine, so that the small machines A and B start to run under pure condensing conditions. In the pure condensing condition, the steam inlet system has an electric steam inlet valve, a manual steam inlet valve, a drain valve and a condenser to adjust the system pressure and ensure the safety of the system;
[0042] (2) When the system is operating under high back pressure conditions, first open the manual valve of the auxiliary steam source system, and then open the check valve and the front and rear drain valves before the steam inlet valve of the small machine to make the auxiliary steam source system come in The steam passes through the quick-closing valve and the regulating valve in front of the small engine, enters the A and B small engines, so that the A and B small engines respectively start heating operation under high back pressure conditions;
[0043] (3) When the auxiliary steam source system drives the small engines A and B to operate normally, then open (manually) the intake valve of the cold re-coming steam source system and the drain valve of the cold re-supply small unit to make the cold re-coming steam pass through the cooling system. Then supply the pressure adjustment of the check valve of the small machine and the high-pressure oil motor, the drain valve after the pipeline valve is adjusted, the speed-closing valve and the steam valve before the small machine are adjusted, so that the cold recoming steam enters the small machines A and B, and puts it into the high back Operation under pressure conditions. At this time, manually close the manual valve of the auxiliary steam source, cut off the auxiliary incoming steam, and complete the operational exchange of cold re-coming steam and auxiliary incoming steam.
[0044] In order to ensure safe and stable operation of the small steam turbine gas supply control system, the manual inlet valve, high-pressure oil motive, quick-closing valve, pipeline valve, front and rear traps and condenser devices of cold recombined steam and auxiliary steam source are designed, and Pressure switch blowdown valve and small engine front regulating valve. The above safety devices can ensure the safe and stable operation of small steam turbines using super-strong steam pressure from the cold recombination source. Once an accidental failure occurs in one aspect of the steam supply system of a small steam turbine, the high-pressure oil motor and quick-closing valve can automatically close the system and stop the operation of the small steam turbine. When the control of the electro-hydraulic device fails, the steam inlet valve can also be manually closed to stop the operation of the small steam turbine to ensure the production safety of the small steam turbine system operation.
[0045] Such as image 3 As shown, in the implementation, a small steam turbine adjustment and control system is also used. The small steam turbine adjustment and control system is designed with a system monitoring operation device. The operation console of the device can issue hydraulic and electrical control commands to the system according to the system control needs, and the system Security assurance control instructions.
[0046] In the embodiment, the small steam turbine adjustment control system is designed with three steam sources: working steam source, commissioning steam source, and backup steam source. When the small steam turbine adjustment control system is started, first start and debug the steam source, the steam power of the debug steam source enters the small steam turbine adjustment control system through the pipeline valve and dampers, and the debug steam source passes low-speed debugging, that is, electrical and mechanical debugging, and open the start valve , Through the accelerator, quick-closing valve and speed regulating valve, reach the steam turbine of the small steam turbine, push the steam turbine to rotate, and drive the small steam turbine to start. When the small steam turbine regulation and control system is operating normally, the working steam source is turned on, and the debugging steam source is closed, and the small steam turbine enters the normal operating state.
[0047] The small steam turbine regulating and control system is designed with a safety guarantee control device. The quick-closing valve can emergency cut off the steam source when the system encounters water hammer and other unexpected accidents, automatically shut down the system, and stop the operation of the small turbine; the emergency shutoff valve is used when the small steam turbine is adjusted When the control system stops abnormally, a critical shutoff valve acts on the system to reduce the damage of steam pressure to the small machine system; and the amplifier can protect the hydraulic and electrical systems such as servo valves.
[0048] The above description is only a description of the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications made by ordinary engineers in the art to the technical solutions of the present invention All improvements and improvements should fall within the scope of protection determined by the claims of the present invention.
