Steam turbine low-pressure cylinder zero output and steam turbine bypass combined ultra-deep peak shaving method

Abstract

The invention discloses a steam turbine low-pressure cylinder zero output and steam turbine bypass combined ultra-deep peak shaving method, and adopts a steam turbine low-pressure cylinder zero output and steam turbine bypass combined ultra-deep peak shaving system. The system comprises a steam turbine high-pressure cylinder, a steam turbine intermediate-pressure cylinder, a steam turbine low-pressure cylinder, a main steam pipeline from a boiler to a steam turbine, a high-pressure bypass pipeline, a peak regulation low-pressure bypass pipeline and a low-pressure bypass pipeline. During heat supply in winter, when a power grid requires peak regulation of a unit, a steam turbine bypass system is used for supplying heat and industrial steam, so that the requirements of heat consumers are met, the steam inlet amount of a steam turbine is reduced, the load of the steam turbine is reduced, the temperatures of main steam and reheated steam are greatly reduced, the enthalpy values of the main steam and the reheated steam are reduced, and the load of the steam turbine is further reduced; and ultra-deep peak regulation is achieved through zero-output operation of a low-pressure cylinder of the steam turbine. According to the invention, the load of the steam turbine is further reduced while the requirements of heat supply and industrial steam quantity are met in winter, and the purpose of ultra-deep peak regulation is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of cogeneration of thermal power plants, and in particular relates to an ultra-deep peak regulation method combining zero output of a low-pressure cylinder of a steam turbine with a steam turbine bypass. Background Art

[0002] The cogeneration project of thermal power plants is mainly used in the fields of industrial steam supply and residential central heating. The temperature in northern my country is relatively low in winter, and as the ambient temperature drops, the heat supply of the cogeneration system needs to be increased, and the electrical load also increases. Under the deep peak-shaving conditions of thermal power plants, thermal power units need to reduce the power generation load. Reducing the power generation load at the traditional technical level will affect the output of heat and steam supply.

[0003] Peak regulation using the turbine bypass system can meet the demand for heating and steam supply while reducing the electrical load of the unit to achieve the purpose of grid peak regulation. However, due to the large amount of heating and steam supply required in winter, the electrical load of the unit cannot be further reduced, and ultra-deep peak regulation cannot be achieved. An ultra-deep peak regulation method is urgently needed in the prior art to further reduce the turbine load while meeting the demand for heating and industrial steam in winter to achieve the purpose of ultra-deep peak regulation. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and to provide a method for ultra-deep peak regulation by combining zero output of the low-pressure cylinder of a turbine with a turbine bypass, so as to further reduce the turbine load while meeting the demand for heating and industrial steam in winter, thereby achieving the purpose of ultra-deep peak regulation.

[0005] The object of the present invention is achieved through the following technical solutions: a method for ultra-deep peak regulation of a low-pressure cylinder of a steam turbine with zero output and a turbine bypass, which adopts an ultra-deep peak regulation system of a low-pressure cylinder of a steam turbine with zero output and a turbine bypass, the system comprises a high-pressure cylinder of a steam turbine, an intermediate-pressure cylinder of a steam turbine, a low-pressure cylinder of a steam turbine and a main steam pipeline from a boiler to a steam turbine, the output end of the main steam pipeline is connected to a boiler reheater steam inlet pipeline via a high-pressure bypass pipeline, a high-pressure bypass steam inlet electric valve, a high-pressure bypass steam inlet regulating valve and a first desuperheater are sequentially arranged on the high-pressure bypass pipeline from front to back, the output end of the main steam pipeline is connected to a high-pressure cylinder of a steam turbine via a high-pressure cylinder steam inlet pipeline; the exhaust steam of the high-pressure cylinder enters a boiler reheater steam inlet pipeline through a high-pressure cylinder exhaust check valve; the boiler reheater steam inlet pipeline is connected to the inlet of the boiler reheater; The outlet of the boiler reheater is connected to the reheater steam outlet pipeline, and the output end of the reheater steam outlet pipeline is connected to the heating steam supply mother pipe through the peak-shaving low-pressure bypass pipeline. The peak-shaving low-pressure bypass steam inlet electric valve, the peak-shaving low-pressure bypass steam inlet regulating valve, the second desuperheater and the low-pressure bypass third steam outlet electric valve are arranged on the peak-shaving low-pressure bypass pipeline from front to back; the output end of the reheater steam outlet pipeline is connected to the industrial steam supply pipeline and the first steam inlet pipeline of the condenser through the low-pressure bypass pipeline, and the low-pressure bypass steam inlet electric valve, the low-pressure bypass steam inlet regulating valve and the third desuperheater are arranged on the low-pressure bypass pipeline from front to back. The industrial steam supply electric valve is arranged between the low-pressure bypass pipeline and the industrial steam supply pipeline, and the low-pressure bypass second steam outlet electric valve is arranged between the low-pressure bypass pipeline and the first steam inlet pipeline of the condenser. The first steam inlet pipeline of the condenser is connected to the condenser; the output end of the reheater steam outlet pipeline is connected to the steam inlet of the intermediate pressure cylinder of the steam turbine through the intermediate pressure cylinder steam inlet pipeline; The exhaust steam from the intermediate pressure cylinder of the steam turbine enters the low pressure cylinder of the steam turbine through the exhaust steam hydraulic control valve and the low pressure cylinder steam inlet pipe. The exhaust steam from the intermediate pressure cylinder of the steam turbine enters the low pressure cylinder of the steam turbine through the cooling steam electric valve and the low pressure cylinder steam inlet pipe. The exhaust steam from the intermediate pressure cylinder of the steam turbine enters the heating steam supply main pipe through the first exhaust steam valve of the intermediate pressure cylinder. The exhaust steam from the low-pressure cylinder of the steam turbine enters the condenser through the second steam inlet pipe of the condenser; The ultra-deep peak modulation method comprises the following steps: Reduce the unit's electrical load from 80%-100% to 60% of the rated load. When the unit's electrical load is 60% of the rated load, maintain the boiler output unchanged, close the second steam outlet electric valve of the low-pressure bypass, open the first steam outlet electric valve of the low-pressure bypass, open the low-pressure bypass steam inlet electric valve, adjust the low-pressure bypass steam inlet regulating valve, close the second steam exhaust valve of the medium-pressure cylinder, and use the low-pressure bypass to supply industrial steam; adjust the steam supply pressure by adjusting the low-pressure bypass steam inlet regulating valve to maintain a steam supply of 60t / h-80t / h, and adjust the steam supply temperature by adjusting the low-pressure bypass desuperheating water regulating valve to meet the user's steam parameter requirements; Open the high-pressure bypass steam inlet electric valve and adjust the high-pressure bypass steam inlet regulating valve. By adjusting the high-pressure bypass steam inlet regulating valve, the steam flow rate after high-pressure bypass temperature reduction and pressure reduction is maintained consistent with the steam flow rate after low-pressure bypass temperature reduction and pressure reduction, so that the axial thrust of the high-pressure rotor and the medium-pressure rotor of the steam turbine is balanced. The steam temperature of the high-pressure bypass output is controlled within 300-340℃ by adjusting the high-pressure bypass desuperheating water regulating valve; Open the third steam outlet electric valve of the low-pressure bypass, open the peak-shaving low-pressure bypass steam inlet electric valve, adjust the peak-shaving low-pressure bypass steam inlet regulating valve, increase the heating steam supply, and maintain the normal heating heat supply of 400GJ / h of the unit; When adjusting the peak-shaving low-pressure bypass steam inlet regulating valve, the high-pressure bypass steam inlet regulating valve is adjusted synchronously to maintain the sum of the steam flow after low-pressure bypass temperature reduction and pressure reduction plus the steam flow after low-pressure bypass temperature reduction and pressure reduction consistent with the steam flow after high-pressure bypass temperature reduction and pressure reduction, so that the axial thrust of the high-pressure rotor and the medium-pressure rotor of the steam turbine is balanced, and the main steam temperature of the main steam pipeline and the reheat steam temperature of the reheater outlet pipeline are reduced from 535°C under normal conditions to 510°C at a temperature drop rate of 1°C-2°C per minute; When the low-pressure bypass, peak-shaving low-pressure bypass, and high-pressure bypass are adjusted and stabilized, the boiler output remains unchanged, the steam inlet of the low-pressure bypass, peak-shaving low-pressure bypass, and high-pressure bypass increases, and the steam inlet of the steam turbine decreases, and the unit electrical load drops from 60% of the rated load to 30% of the rated load; After the unit load stabilizes, continue to reduce the main steam temperature of the main steam pipeline and the reheat steam temperature of the reheater outlet steam pipeline from 510℃ to 460℃ at a temperature drop rate of 1℃-2℃ per minute, reduce the enthalpy of the turbine inlet steam, ensure the industrial steam supply of 60t / h-80t / h, heating heat supply of 400GJ / h, and reduce the unit electrical load to 27% of the rated load; Fully open the first exhaust valve of the intermediate pressure cylinder, open the cooling steam electric valve, close the exhaust hydraulic control valve, reduce the steam intake of the low-pressure cylinder of the steam turbine, so that the steam entering the low-pressure cylinder of the steam turbine is only used for cooling the low-pressure rotor blades, and achieve zero output of the low-pressure cylinder of the steam turbine; After the steam inlet to the low-pressure cylinder of the turbine is reduced, the opening of the first exhaust valve of the intermediate-pressure cylinder is widened, the heating heat supply is increased to 500GJ / h, the unit electrical load is reduced from 27% of the rated load to 12% of the rated load, and the boiler load is reduced by 10%, maintaining the industrial steam supply at 60t / h-80t / h and the heating heat supply at 400GJ / h, achieving ultra-deep peak regulation.

[0006] The cooling water inlet of the first cooler is connected with a high-pressure bypass cooling water regulating valve.

[0007] The cooling water inlet of the second cooler is connected with a peak-shaving low-pressure bypass cooling water regulating valve.

[0008] The cooling water inlet of the third cooler is connected with a low-pressure bypass cooling water regulating valve.

[0009] The beneficial effects of the present invention are as follows: during the winter heating period, when the power grid requires the unit to peak load, the turbine bypass system is used to supply heating and industrial steam to meet the needs of heat users, reduce the steam intake of the turbine, reduce the turbine load, and at the same time greatly reduce the main steam and reheat steam temperatures, reduce the enthalpy of the main steam and reheat steam, further reduce the turbine load, and then achieve ultra-deep peak load by operating the low-pressure cylinder of the turbine at zero output. While meeting the heating and industrial steam demand in winter, the present invention further reduces the turbine load to achieve the purpose of ultra-deep peak load regulation, and the peak load regulation effect is good. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a structural schematic diagram of the present invention.

[0011] In the figure: 1-steam turbine high pressure cylinder; 2-steam turbine medium pressure cylinder; 3-steam turbine low pressure cylinder; 4-generator; 5-boiler reheater; 6-main steam pipeline; 7-high pressure cylinder steam inlet pipeline; 8-high pressure cylinder exhaust check valve; 9-boiler reheater steam inlet pipeline; 10-peak shaving low pressure bypass pipeline; 11-low pressure bypass pipeline; 12-medium pressure cylinder steam inlet pipeline; 13-high pressure bypass steam inlet electric valve; 14-high pressure bypass steam inlet regulating valve; 15-first desuperheater; 16-high pressure bypass desuperheating water regulating valve; 17-peak shaving low pressure bypass steam inlet electric valve; 18-peak shaving low pressure bypass steam inlet regulating valve; 19-peak shaving low pressure bypass desuperheating water regulating valve; 20-low pressure bypass steam inlet electric valve Door; 21-low-pressure bypass steam inlet regulating valve; 22-low-pressure bypass cooling water regulating valve; 23-low-pressure bypass first steam outlet electric valve; 24-low-pressure bypass second steam outlet electric valve; 25-low-pressure bypass third steam outlet electric valve; 26-exhaust hydraulic control regulating valve; 27-reheater steam outlet pipeline; 28-low-pressure cylinder steam inlet pipeline; 29-medium-pressure cylinder first exhaust valve; 30-cooling steam electric valve; 31-high-pressure bypass pipeline; 32-heating steam supply mother pipe; 33-industrial steam supply pipeline; 34-condenser first steam inlet pipeline; 35-condenser second steam inlet pipeline; 36-condenser; 37-medium-pressure cylinder second exhaust valve; 38-second desuperheater; 39-third desuperheater. DETAILED DESCRIPTION

[0012] The present invention is described in detail below in conjunction with the accompanying drawings.

[0013] like Figure 1As shown, a method for ultra-deep peak regulation of a steam turbine low-pressure cylinder zero output and a steam turbine bypass is adopted, and an ultra-deep peak regulation system of a steam turbine low-pressure cylinder zero output and a steam turbine bypass is adopted, the system comprises a steam turbine high-pressure cylinder 1, a steam turbine medium-pressure cylinder 2, a steam turbine low-pressure cylinder 3 and a main steam pipeline 6 from a boiler to a steam turbine, the output end of the main steam pipeline 6 is connected to a boiler reheater steam inlet pipeline 9 via a high-pressure bypass pipeline 31, a high-pressure bypass steam inlet electric valve 13, a high-pressure bypass steam inlet regulating valve 14 and a first desuperheater 15 are sequentially arranged on the high-pressure bypass pipeline 31 from front to back, a desuperheating water inlet of the first desuperheater 15 is connected to a high-pressure bypass desuperheating water regulating valve 16, the output end of the main steam pipeline 6 is connected to the steam turbine high-pressure cylinder 1 via a high-pressure cylinder steam inlet pipeline 7; the high-pressure cylinder exhaust steam enters the boiler reheater steam inlet pipeline 9 through a high-pressure cylinder exhaust check valve 8; the boiler reheater steam inlet pipeline 9 is connected to the inlet of the boiler reheater 5; The outlet of the boiler reheater 5 is connected to the reheater steam outlet pipe 27, and the output end of the reheater steam outlet pipe 27 is connected to the heating steam supply main pipe 32 via the peak-shaving low-pressure bypass pipe 10. The peak-shaving low-pressure bypass steam inlet electric valve 17, the peak-shaving low-pressure bypass steam inlet regulating valve 18, the second desuperheater 38 and the low-pressure bypass third steam outlet electric valve 25 are arranged on the peak-shaving low-pressure bypass pipe 10 from front to back. The cooling water inlet of the second desuperheater 38 is connected to the peak-shaving low-pressure bypass cooling water regulating valve 19; the output end of the reheater steam outlet pipe 27 is connected to the industrial steam supply pipe 33 and the first steam inlet pipe 34 of the condenser via the low-pressure bypass pipe 11, and the low-pressure The bypass pipe 11 is provided with a low-pressure bypass steam inlet electric valve 20, a low-pressure bypass steam inlet regulating valve 21 and a third desuperheater 39 in sequence from front to back. The desuperheating water inlet of the third desuperheater 39 is connected with a low-pressure bypass desuperheating water regulating valve 22. An industrial steam supply electric valve 23 is provided between the low-pressure bypass pipe 11 and the industrial steam supply pipe 33. A low-pressure bypass second steam outlet electric valve 24 is provided between the low-pressure bypass pipe 11 and the first steam inlet pipe 34 of the condenser. The first steam inlet pipe 34 of the condenser is connected with the condenser 36. The output end of the reheater steam outlet pipe 27 is connected with the steam inlet of the intermediate pressure cylinder 2 of the steam turbine through the intermediate pressure cylinder steam inlet pipe 12. The exhaust steam of the steam turbine intermediate pressure cylinder 2 enters the steam turbine low pressure cylinder 3 through the exhaust steam hydraulic control valve 26 and the low pressure cylinder steam inlet pipe 28; the exhaust steam of the steam turbine intermediate pressure cylinder 2 enters the steam turbine low pressure cylinder 3 through the cooling steam electric valve 30 and the low pressure cylinder steam inlet pipe 28; the exhaust steam of the steam turbine intermediate pressure cylinder 2 enters the heating steam supply main pipe 32 through the first exhaust steam valve 29 of the intermediate pressure cylinder; The exhaust steam from the low-pressure cylinder 3 of the steam turbine enters the condenser 36 through the second steam inlet pipe 35 of the condenser.

[0014] The ultra-deep peak shaving method comprises the following steps: When the power grid needs to be peak-loaded during the winter heating period, the units of the thermal power plant must reduce the unit's power generation load while ensuring normal residential heating and industrial steam supply. First, reduce the unit's power load from 80%-100% to 60% of the rated load. When the unit's power load is 60% of the rated load, maintain the boiler output unchanged, switch to the industrial steam supply source, close the second steam outlet electric valve 24 of the low-pressure bypass, open the first steam outlet electric valve 23 of the low-pressure bypass, open the low-pressure bypass steam inlet electric valve 20, adjust the low-pressure bypass steam inlet regulating valve 21, close the second exhaust valve 37 of the medium-pressure cylinder, and use the low-pressure bypass to supply industrial steam.

[0015] When the unit load drops to 60% of the rated load, the second exhaust valve 37 of the intermediate pressure cylinder is fully closed, and the industrial steam is supplied entirely by the low-pressure bypass. The steam supply pressure is adjusted by adjusting the low-pressure bypass steam inlet regulating valve 21 to maintain the steam supply volume at 60t / h-80t / h, and the steam supply temperature is adjusted by adjusting the low-pressure bypass desuperheating water regulating valve 22 to meet the user's steam parameter requirements.

[0016] Open the high-pressure bypass steam inlet electric valve 13, adjust the high-pressure bypass steam inlet regulating valve 14, and maintain the steam flow rate after high-pressure bypass temperature reduction and pressure reduction consistent with the steam flow rate after low-pressure bypass temperature reduction and pressure reduction by adjusting the high-pressure bypass steam inlet regulating valve 14, so that the axial thrust of the high-pressure rotor and the medium-pressure rotor of the steam turbine is balanced. The steam temperature of the high-pressure bypass output is controlled within 300-340℃ by adjusting the high-pressure bypass desuperheating water regulating valve 16.

[0017] Open the third steam outlet electric valve 25 of the low-pressure bypass, open the peak-shaving low-pressure bypass steam inlet electric valve 17, adjust the peak-shaving low-pressure bypass steam inlet regulating valve 18, increase the heating steam supply, and maintain the normal heating heat supply of the unit at 400GJ / h.

[0018] When adjusting the peak-shaving low-pressure bypass steam inlet regulating valve 18, the high-pressure bypass steam inlet regulating valve 14 is adjusted synchronously to maintain the sum of the steam flow after low-pressure bypass temperature reduction and pressure reduction plus the steam flow after low-pressure bypass temperature reduction and pressure reduction consistent with the steam flow after high-pressure bypass temperature reduction and pressure reduction, so that the axial thrust of the high-pressure rotor and the medium-pressure rotor of the steam turbine is balanced. The main steam temperature of the main steam pipeline 6 and the reheated steam temperature of the reheater outlet steam pipeline 27 are reduced from 535°C under normal conditions to 510°C at a temperature drop rate of 1°C-2°C per minute.

[0019] When the low-pressure bypass, peak-shaving low-pressure bypass and high-pressure bypass are adjusted and stabilized, the boiler output remains unchanged, the steam intake of the low-pressure bypass, peak-shaving low-pressure bypass and high-pressure bypass increases, the steam intake of the turbine decreases, and the unit electrical load drops from 60% of the rated load to 30% of the rated load.

[0020] After the unit load stabilizes, the main steam temperature of the main steam pipe 6 and the reheat steam temperature of the reheater outlet steam pipe 27 are continuously reduced from 510°C to 460°C at a temperature drop rate of 1°C-2°C per minute, thereby reducing the enthalpy of the turbine inlet steam. This can ensure an industrial steam supply of 60t / h-80t / h and a heating heat supply of 400GJ / h, and the unit electrical load is reduced to 27% of the rated load.

[0021] In order to further reduce the electrical load of the unit, the first exhaust valve 29 of the intermediate pressure cylinder is fully opened, the cooling steam electric valve 30 is opened, the exhaust hydraulic control valve 26 is closed, and the steam intake of the low-pressure cylinder 3 of the steam turbine is reduced, so that the steam entering the low-pressure cylinder of the steam turbine is only used for cooling the low-pressure rotor blades, thereby achieving zero output of the low-pressure cylinder of the steam turbine.

[0022] After the steam inlet to the low-pressure cylinder of the turbine is reduced, the opening of the first exhaust valve 29 of the intermediate-pressure cylinder is widened, the heating heat supply is increased to 500GJ / h, the unit electrical load is reduced from 27% of the rated load to 12% of the rated load, and the boiler load is reduced by 10%, maintaining the industrial steam supply at 60t / h-80t / h and the heating heat supply at 400GJ / h, achieving ultra-deep peak regulation.

[0023] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions of the technical solution of the present invention by ordinary technicians in this field do not deviate from the essence and scope of the technical solution of the present invention.

Claims

1. A method for ultra-deep peak regulation combining zero output of low-pressure cylinder of steam turbine and steam turbine bypass, characterized in that: The system adopts the ultra-deep peak regulation system of the zero output of the low-pressure cylinder of the steam turbine and the turbine bypass. The system includes the high-pressure cylinder of the steam turbine, the medium-pressure cylinder of the steam turbine, the low-pressure cylinder of the steam turbine and the main steam pipeline from the boiler to the steam turbine. The output end of the main steam pipeline is connected to the boiler reheater steam inlet pipeline through the high-pressure bypass pipeline. The high-pressure bypass steam inlet electric valve, the high-pressure bypass steam inlet regulating valve and the first desuperheater are arranged on the high-pressure bypass pipeline from front to back. The output end of the main steam pipeline is connected to the high-pressure cylinder of the steam turbine through the high-pressure cylinder steam inlet pipeline; the high-pressure cylinder exhaust steam enters the boiler reheater steam inlet pipeline through the high-pressure cylinder exhaust check valve; the boiler reheater steam inlet pipeline is connected to the inlet of the boiler reheater; The outlet of the boiler reheater is connected to the reheater steam outlet pipeline, and the output end of the reheater steam outlet pipeline is connected to the heating steam supply mother pipe through the peak-shaving low-pressure bypass pipeline. The peak-shaving low-pressure bypass steam inlet electric valve, the peak-shaving low-pressure bypass steam inlet regulating valve, the second desuperheater and the low-pressure bypass third steam outlet electric valve are arranged on the peak-shaving low-pressure bypass pipeline from front to back; the output end of the reheater steam outlet pipeline is connected to the industrial steam supply pipeline and the first steam inlet pipeline of the condenser through the low-pressure bypass pipeline, and the low-pressure bypass steam inlet electric valve, the low-pressure bypass steam inlet regulating valve and the third desuperheater are arranged on the low-pressure bypass pipeline from front to back. The industrial steam supply electric valve is arranged between the low-pressure bypass pipeline and the industrial steam supply pipeline, and the low-pressure bypass second steam outlet electric valve is arranged between the low-pressure bypass pipeline and the first steam inlet pipeline of the condenser. The first steam inlet pipeline of the condenser is connected to the condenser; the output end of the reheater steam outlet pipeline is connected to the steam inlet of the intermediate pressure cylinder of the steam turbine through the intermediate pressure cylinder steam inlet pipeline; The exhaust steam from the intermediate pressure cylinder of the steam turbine enters the low pressure cylinder of the steam turbine through the exhaust steam hydraulic control valve and the low pressure cylinder steam inlet pipe. The exhaust steam from the intermediate pressure cylinder of the steam turbine enters the low pressure cylinder of the steam turbine through the cooling steam electric valve and the low pressure cylinder steam inlet pipe. The exhaust steam from the intermediate pressure cylinder of the steam turbine enters the heating steam supply main pipe through the first exhaust steam valve of the intermediate pressure cylinder. The exhaust steam from the low-pressure cylinder of the steam turbine enters the condenser through the second steam inlet pipe of the condenser; The ultra-deep peak modulation method comprises the following steps: Reduce the unit's electrical load from 80%-100% to 60% of the rated load. When the unit's electrical load is 60% of the rated load, maintain the boiler output unchanged, close the second steam outlet electric valve of the low-pressure bypass, open the first steam outlet electric valve of the low-pressure bypass, open the low-pressure bypass steam inlet electric valve, adjust the low-pressure bypass steam inlet regulating valve, close the second steam exhaust valve of the medium-pressure cylinder, and use the low-pressure bypass to supply industrial steam; adjust the steam supply pressure by adjusting the low-pressure bypass steam inlet regulating valve to maintain a steam supply of 60t / h-80t / h, and adjust the steam supply temperature by adjusting the low-pressure bypass desuperheating water regulating valve to meet the user's steam parameter requirements; Open the high-pressure bypass steam inlet electric valve and adjust the high-pressure bypass steam inlet regulating valve. By adjusting the high-pressure bypass steam inlet regulating valve, the steam flow rate after high-pressure bypass temperature reduction and pressure reduction is maintained consistent with the steam flow rate after low-pressure bypass temperature reduction and pressure reduction, so that the axial thrust of the high-pressure rotor and the medium-pressure rotor of the steam turbine is balanced. The steam temperature of the high-pressure bypass output is controlled within 300-340℃ by adjusting the high-pressure bypass desuperheating water regulating valve; Open the third steam outlet electric valve of the low-pressure bypass, open the peak-shaving low-pressure bypass steam inlet electric valve, adjust the peak-shaving low-pressure bypass steam inlet regulating valve, increase the heating steam supply, and maintain the normal heating heat supply of 400GJ / h of the unit; When adjusting the peak-shaving low-pressure bypass steam inlet regulating valve, the high-pressure bypass steam inlet regulating valve is adjusted synchronously to maintain the sum of the steam flow after low-pressure bypass temperature reduction and pressure reduction plus the steam flow after low-pressure bypass temperature reduction and pressure reduction consistent with the steam flow after high-pressure bypass temperature reduction and pressure reduction, so that the axial thrust of the high-pressure rotor and the medium-pressure rotor of the steam turbine is balanced, and the main steam temperature of the main steam pipeline and the reheat steam temperature of the reheater outlet pipeline are reduced from 535°C under normal conditions to 510°C at a temperature drop rate of 1°C-2°C per minute; When the low-pressure bypass, peak-shaving low-pressure bypass, and high-pressure bypass are adjusted and stabilized, the boiler output remains unchanged, the steam inlet of the low-pressure bypass, peak-shaving low-pressure bypass, and high-pressure bypass increases, and the steam inlet of the steam turbine decreases, and the unit electrical load drops from 60% of the rated load to 30% of the rated load; After the unit load stabilizes, continue to reduce the main steam temperature of the main steam pipeline and the reheat steam temperature of the reheater outlet steam pipeline from 510℃ to 460℃ at a temperature drop rate of 1℃-2℃ per minute, reduce the enthalpy of the turbine inlet steam, ensure the industrial steam supply of 60t / h-80t / h, heating heat supply of 400GJ / h, and reduce the unit electrical load to 27% of the rated load; Fully open the first exhaust valve of the intermediate pressure cylinder, open the cooling steam electric valve, close the exhaust hydraulic control valve, reduce the steam intake of the low-pressure cylinder of the steam turbine, so that the steam entering the low-pressure cylinder of the steam turbine is only used for cooling the low-pressure rotor blades, and achieve zero output of the low-pressure cylinder of the steam turbine; After the steam inlet to the low-pressure cylinder of the turbine is reduced, the opening of the first exhaust valve of the intermediate-pressure cylinder is widened, the heating heat supply is increased to 500GJ / h, the unit electrical load is reduced from 27% of the rated load to 12% of the rated load, and the boiler load is reduced by 10%, maintaining the industrial steam supply at 60t / h-80t / h and the heating heat supply at 400GJ / h, achieving ultra-deep peak regulation.

2. The method for ultra-deep peak regulation combining zero output of low-pressure cylinder of steam turbine and steam turbine bypass according to claim 1 is characterized in that: The cooling water inlet of the first cooler is connected with a high-pressure bypass cooling water regulating valve.

3. The method for ultra-deep peak regulation combining zero output of low-pressure cylinder of steam turbine and steam turbine bypass according to claim 1 is characterized in that: The cooling water inlet of the second cooler is connected with a peak-shaving low-pressure bypass cooling water regulating valve.

4. The method for ultra-deep peak regulation combining zero output of low-pressure cylinder of steam turbine and steam turbine bypass according to claim 1 is characterized in that: The cooling water inlet of the third cooler is connected with a low-pressure bypass cooling water regulating valve.

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