Coupling peak load regulation system based on main steam, intermediate exhaust and extraction steam cooling and its operation method

Abstract

The present invention is based on a coupled peak-shaving system for main steam, intermediate exhaust and extraction steam cooling and its operation method, the system includes a high-pressure main steam valve, an intermediate-pressure cylinder, a low-pressure cylinder, a condensate pump, an intermediate-pressure cylinder exhaust control, an isolation valve group, a main steam connecting pipe control, an isolation valve group, an intermediate-pressure cylinder exhaust connecting pipe control, an isolation valve group, a low-pressure feedwater connecting pipe control, an isolation valve group, a low-pressure cylinder extraction connecting pipe control, an isolation valve group, a high- and intermediate-pressure cylinder minimum cooling steam inlet pipeline control, an isolation valve group, a low-pressure cylinder minimum cooling steam pipeline control, an isolation valve group, a main steam connecting pipe, an intermediate-pressure cylinder exhaust connecting pipe, and a low-pressure cylinder minimum cooling steam pipeline, etc.; the operation method realizes the flexible switching of two groups of conventional unit-based generator sets. The present invention can improve the deep peak-shaving capability of the unit and increase the flexibility of the unit operation without technical transformation of the boiler side.

Description

Technical Field

[0001] The present invention belongs to the technical field of thermal power generation, and in particular relates to a coupled peak-shaving system based on main steam, intermediate exhaust and extraction steam cooling and an operation method thereof. Background Art

[0002] At present, domestic large-capacity thermal power plants widely adopt the unit operation method, that is, one boiler supplies steam to one steam turbine, and the steam turbine drives the generator to generate electricity, forming an independent power generation unit of boiler-turbine-generator. There is basically no horizontal connection between the various power generation units. Due to the minimum stable combustion output limit of coal-fired boilers without auxiliary fuel, the minimum electrical load of existing thermal power units is generally limited to about 30%-40%. Further reduction will have an adverse effect on the safe and continuous operation of the boiler. China's invention patent disclosure specification CN109653810A discloses a thermal system with one boiler and two machines switching operation. By adding superheated steam and reheated steam bypass and control valves, when one boiler fails, another boiler is used to drive two steam turbines to generate electricity. At this time, the unit has a certain peak-shaving capacity, but the system layout is relatively complex, the operation flexibility is low, and the operability in the actual operation of the power plant is poor.

[0003] In recent years, with the continuous advancement of the upgrading and transformation of thermal power units, there is an urgent need to propose a thermal system and operation method that can realize the coupling connection between large-capacity thermal power units, so as to enhance the flexibility of the units to adapt to the dispatching power load instructions and improve the deep peak regulation capability of the units. Summary of the invention

[0004] In response to the problems existing in the prior art, the present invention provides a coupled peak-shaving system based on main steam, intermediate exhaust and extraction steam cooling and an operation method thereof, which can improve the deep peak-shaving capability of the unit and increase the flexibility of the unit operation without the need for technical transformation of the boiler side.

[0005] The present invention is achieved through the following technical solutions:

[0006] A coupled peak-shaving system based on main steam, intermediate exhaust and extraction steam cooling, comprising a first conventional unit-based generator set and a second conventional unit-based generator set;

[0007] Specifically, it includes the first high-pressure main steam valve, the second high-pressure main steam valve, the first high-pressure cylinder, the second high-pressure cylinder, the first intermediate-pressure cylinder, the second intermediate-pressure cylinder, the first low-pressure cylinder, the second low-pressure cylinder, the first condensate pump, the second condensate pump, the first intermediate-pressure cylinder exhaust control and isolation valve group, the second intermediate-pressure cylinder exhaust control and isolation valve group, the main steam connecting pipe control and isolation valve group, the intermediate-pressure cylinder exhaust connecting pipe control and isolation valve group, the low-pressure feed water connecting pipe control and isolation valve group, the low-pressure cylinder extraction connecting pipe control and isolation valve group, the first high and intermediate pressure cylinder minimum cooling steam inlet pipeline control and isolation valve group , the second high and medium pressure cylinder minimum cooling steam inlet pipeline control and isolation valve group, the first low pressure cylinder minimum cooling steam pipeline control and isolation valve group, the second low pressure cylinder minimum cooling steam pipeline control and isolation valve group, the main steam connecting pipe, the medium pressure cylinder exhaust connecting pipe, the low pressure feed water connecting pipe, the low pressure cylinder extraction connecting pipe, the first low pressure cylinder extraction pipe, the second low pressure cylinder extraction pipe, the first high and medium pressure cylinder minimum cooling steam inlet pipeline, the second high and medium pressure cylinder minimum cooling steam inlet pipeline, and the first low pressure cylinder minimum cooling steam pipeline, the second low pressure cylinder minimum cooling steam pipeline;

[0008] The intermediate pressure cylinder exhaust connecting pipe is connected between the exhaust outlet of the first intermediate pressure cylinder and the exhaust outlet of the second intermediate pressure cylinder of the two steam turbines, and the intermediate pressure cylinder exhaust connecting pipe is equipped with an intermediate pressure cylinder exhaust connecting pipe control and isolation valve group;

[0009] The main steam connecting pipe is connected between the steam inlet of the first high-pressure main steam valve and the steam inlet of the second high-pressure main steam valve of the two steam turbines. The main steam connecting pipe is equipped with a main steam connecting pipe control and isolation valve group;

[0010] The first intermediate pressure cylinder exhaust control and isolation valve group is connected between the exhaust port of the first intermediate pressure cylinder and the steam inlet of the first low pressure cylinder, and the second intermediate pressure cylinder exhaust control and isolation valve group is connected between the exhaust port of the second intermediate pressure cylinder and the steam inlet of the second low pressure cylinder;

[0011] The low-pressure cylinder steam extraction connecting pipe is connected between the first low-pressure cylinder steam extraction pipe and the second low-pressure cylinder steam extraction pipe of the two steam turbines, and the low-pressure cylinder steam extraction connecting pipe is equipped with a low-pressure cylinder steam extraction connecting pipe control and isolation valve group;

[0012] The minimum cooling steam pipeline of the first low-pressure cylinder is connected between the low-pressure cylinder extraction connecting pipe and the steam inlet of the first low-pressure cylinder, the minimum cooling steam pipeline of the second low-pressure cylinder is connected between the low-pressure cylinder extraction connecting pipe and the steam inlet of the second low-pressure cylinder, the first low-pressure cylinder minimum cooling steam pipeline control and isolation valve group are installed on the minimum cooling steam pipeline of the first low-pressure cylinder, and the second low-pressure cylinder minimum cooling steam pipeline control and isolation valve group are installed on the minimum cooling steam pipeline of the second low-pressure cylinder;

[0013] The minimum cooling steam inlet pipeline of the first high- and medium-pressure cylinder is connected between the inlet and outlet of the first high-pressure main steam valve, and the minimum cooling steam inlet pipeline of the second high- and medium-pressure cylinder is connected between the inlet and outlet of the second high-pressure main steam valve. The minimum cooling steam inlet pipeline of the first high- and medium-pressure cylinder is equipped with a first high- and medium-pressure cylinder minimum cooling steam inlet pipeline control and isolation valve group, and the minimum cooling steam inlet pipeline of the second high- and medium-pressure cylinder is equipped with a second high- and medium-pressure cylinder minimum cooling steam inlet pipeline control and isolation valve group;

[0014] The low-pressure feed water connecting pipe is connected between the outlets of the first condensate pump and the second condensate pump of the two steam turbines, and a low-pressure feed water connecting pipe control and isolation valve group is installed on the low-pressure feed water connecting pipe.

[0015] A further improvement of the present invention is that the first conventional unit-type generator set and the second conventional unit-type generator set have the same power generation capability and equivalent capacity, and the equipment type and thermal system design are consistent.

[0016] A further improvement of the present invention is that the operating status of the first conventional unit-type generator set and the second conventional unit-type generator set is that both boilers and both steam turbines are in an operating state.

[0017] A further improvement of the present invention is that the main steam of the first conventional unit-type generator set can enter the second high-pressure cylinder of the second conventional unit-type generator set through the main steam connecting pipe to perform work;

[0018] The main steam of the second conventional unit-type generator set can enter the first high-pressure cylinder of the first conventional unit-type generator set through the main steam connecting pipe to perform work.

[0019] A further improvement of the present invention is that when the second high-pressure main steam valve of the second conventional unit-type generator set is closed, the main steam of the second conventional unit-type generator set can enter the second high-pressure cylinder and the second medium-pressure cylinder through the second high-pressure and medium-pressure cylinder minimum cooling steam inlet pipeline, thereby ensuring the safe operation of the second high-pressure cylinder and the second medium-pressure cylinder;

[0020] When the first high-pressure main steam valve of the first conventional unit generator set is closed, the main steam of the first conventional unit generator set can enter the first high-pressure cylinder and the first intermediate-pressure cylinder through the first high- and intermediate-pressure cylinder minimum cooling steam inlet pipeline, thereby ensuring the safe operation of the first high-pressure cylinder and the first intermediate-pressure cylinder.

[0021] A further improvement of the present invention is that the exhaust steam of the first intermediate pressure cylinder of the first conventional unit-type generator set can enter the second low pressure cylinder of the second conventional unit-type generator set through the intermediate pressure cylinder exhaust communication pipe to perform work;

[0022] The exhaust steam of the second intermediate pressure cylinder of the second conventional unit-type generator set can enter the first low pressure cylinder of the first conventional unit-type generator set through the intermediate pressure cylinder exhaust steam connecting pipe to perform work.

[0023] A further improvement of the present invention is that the condensate at the outlet of the first condensate pump of the first conventional unit-type generator set enters the low-pressure water supply system of the second conventional unit-type generator set through the low-pressure water supply connecting pipe to maintain the deaerator water level of the second conventional unit-type generator set stable;

[0024] The condensate at the outlet of the second condensate pump of the second conventional unit-type generator set enters the low-pressure water supply system of the first conventional unit-type generator set through the low-pressure water supply connecting pipe to maintain the stability of the deaerator water level of the first conventional unit-type generator set.

[0025] A further improvement of the present invention is that when the exhaust control and isolation valve group of the second intermediate pressure cylinder of the second conventional unit-type generator set is closed, the extraction steam of the low pressure cylinder of the first conventional unit-type generator set can enter the second low pressure cylinder to cool the low pressure cylinder via the first low pressure cylinder extraction pipe, the low pressure cylinder extraction connecting pipe and the second low pressure cylinder minimum cooling steam pipeline, thereby ensuring the safe operation of the second low pressure cylinder;

[0026] When the first intermediate pressure cylinder exhaust control and isolation valve group of the first conventional unit generator set is closed, the low pressure cylinder extraction steam of the second conventional unit generator set can enter the first low pressure cylinder through the second low pressure cylinder extraction pipe, the low pressure cylinder extraction connecting pipe and the first low pressure cylinder minimum cooling steam pipeline to cool the low pressure cylinder, thereby ensuring the safe operation of the first low pressure cylinder.

[0027] The method for operating a coupled peak-shaving system based on main steam, intermediate exhaust and extraction steam cooling is based on the coupled peak-shaving system based on main steam, intermediate exhaust and extraction steam cooling, and comprises the following steps:

[0028] Step 1: The first conventional unit-type generator set and the second conventional unit-type generator set operate normally, and the first high-pressure main steam valve and the second high-pressure main steam valve remain in normal operating state; the main steam connecting pipe of the main steam connecting pipe is controlled and the isolation valve group is in a closed state; the medium-pressure cylinder exhaust connecting pipe of the medium-pressure cylinder exhaust connecting pipe is controlled and the isolation valve group is in a closed state; the low-pressure cylinder extraction connecting pipe of the low-pressure cylinder extraction connecting pipe is controlled and the isolation valve group is in a closed state; the low-pressure water supply connecting pipe of the low-pressure water supply connecting pipe is controlled and the isolation valve group is in a closed state; the first medium-pressure cylinder exhaust control and isolation valve group of the first conventional unit-type generator set are in The first conventional unit-type generator set is in the open state; the first high- and medium-pressure cylinder minimum cooling steam inlet pipeline control and isolation valve group of the first conventional unit-type generator set are in the closed state; the first low-pressure cylinder minimum cooling steam pipeline control and isolation valve group of the first conventional unit-type generator set are in the closed state; the second medium-pressure cylinder exhaust steam control and isolation valve group of the second conventional unit-type generator set are in the open state; the second high- and medium-pressure cylinder minimum cooling steam inlet pipeline control and isolation valve group of the second conventional unit-type generator set are in the closed state; the second low-pressure cylinder minimum cooling steam pipeline control and isolation valve group of the second conventional unit-type generator set are in the closed state;

[0029] Step 2, the main steam connecting pipe of the main steam connecting pipe is controlled, and the isolation valve group is opened; the intermediate pressure cylinder exhaust connecting pipe of the intermediate pressure cylinder exhaust connecting pipe is controlled, and the isolation valve group is opened; the first high and intermediate pressure cylinder minimum cooling steam inlet pipeline of the first conventional unit-based generator set is controlled, and the isolation valve group is opened; the first low pressure cylinder minimum cooling steam pipeline of the first conventional unit-based generator set is controlled, and the isolation valve group is opened; the low pressure cylinder extraction connecting pipe of the low pressure cylinder extraction connecting pipe is controlled, and the isolation valve group is opened; the first high pressure main steam valve of the first conventional unit-based generator set is slowly closed; the first intermediate pressure cylinder exhaust control of the first conventional unit-based generator set, and the isolation valve group are slowly closed; the low pressure feed water connecting pipe of the low pressure feed water connecting pipe is controlled, and the isolation valve group is slowly opened; the water level of the deaerator of the first conventional unit-based generator set is maintained stable; and the deep peak load regulation operation of the first conventional unit-based generator set is realized;

[0030] Step 3: The main steam connecting pipe of the main steam connecting pipe is controlled and the isolation valve group is kept open; the intermediate pressure cylinder exhaust connecting pipe of the intermediate pressure cylinder exhaust connecting pipe is controlled and the isolation valve group is kept open; the first high pressure main steam valve of the first conventional unit generator set is slowly opened; the first intermediate pressure cylinder exhaust control and the isolation valve group of the first conventional unit generator set are slowly opened; the first high and intermediate pressure cylinder minimum cooling steam inlet pipeline of the first conventional unit generator set is controlled and the isolation valve group is slowly closed; the first low pressure cylinder minimum cooling steam pipeline of the first conventional unit generator set is controlled and the isolation valve group is slowly closed. Close; open the second high- and medium-pressure cylinder minimum cooling steam inlet pipeline control and isolation valve group of the second conventional unit-type generator set; open the second low-pressure cylinder minimum cooling steam pipeline control and isolation valve group of the second conventional unit-type generator set; slowly close the second high-pressure main steam valve of the second conventional unit-type generator set; slowly close the second medium-pressure cylinder exhaust control and isolation valve group of the second conventional unit-type generator set; maintain the low-pressure feed water control and isolation valve group open; maintain the water level of the deaerator of the second conventional unit-type generator set stable; realize the deep peak-shaving operation of the second conventional unit-type generator set.

[0031] A further improvement of the present invention is that the first conventional unit-based generator set and the second conventional unit-based generator set are both in a grid-connected power generation state, and any one of the generator sets can participate in deep peak regulation at any time;

[0032] Alternatively, the operating states of the first conventional unit-based generator set and the second conventional unit-based generator set can be switched with each other.

[0033] Compared with the prior art, the present invention has the following beneficial technical effects:

[0034] The present invention realizes the switching of deep peak-shaving operation mode of any unit by adding main steam connecting pipe, medium-pressure cylinder exhaust connecting pipe, low-pressure cylinder extraction connecting pipe, low-pressure water supply connecting pipe, high- and medium-pressure cylinder minimum cooling steam inlet pipelines, and low-pressure cylinder minimum cooling steam pipeline; when a unit is in deep peak-shaving operation, its main steam inlet volume and low-pressure cylinder inlet flow rate can be reduced to the minimum, at which time the unit maintains the minimum working capacity, and the deep peak-shaving capacity of the unit is increased. Utilizing the present invention, under deep peak-shaving operation conditions, most of the main steam and low-pressure cylinder inlet volume of one unit can be transported to another unit, achieving a smaller technical output for one unit. The flexibility of the unit to adapt to the dispatching electric load instructions is enhanced, the deep peak-shaving electricity price income of the power plant is increased, and the production and operation efficiency of the power plant is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic diagram of the thermal system of the coupled peak-shaving system based on main steam, intermediate exhaust and extraction steam cooling described in an example of the present invention.

[0036] Description of reference numerals:

[0037] 1. First intermediate pressure cylinder exhaust control, isolation valve group, 2. Second intermediate pressure cylinder exhaust control, isolation valve group; 3. Intermediate pressure cylinder exhaust communication pipe control, isolation valve group; 4. Intermediate pressure cylinder exhaust communication pipe; 5. Low-pressure water supply communication pipe; 6. Low-pressure water supply communication pipe control, isolation valve group; 7. First intermediate pressure cylinder; 8. First low-pressure cylinder; 9. Second intermediate pressure cylinder; 10. Second low-pressure cylinder; 11. First condensate pump; 12. Second condensate pump; 13. First conventional unit generator set; 14. Second conventional unit generator set; 15. First low-pressure cylinder minimum cooling steam pipeline control, isolation valve group, 17. Second low-pressure cylinder minimum cooling steam pipeline control, isolation valve group; 16. First low-pressure cylinder minimum cooling steam pipeline , 18. The minimum cooling steam pipeline of the second low-pressure cylinder; 19. The extraction pipe of the first low-pressure cylinder; 20. The extraction pipe of the second low-pressure cylinder; 21. The control and isolation valve group of the low-pressure cylinder extraction connecting pipe; 22. The extraction connecting pipe of the low-pressure cylinder; 23. The main steam connecting pipe; 24. The control and isolation valve group of the main steam connecting pipe; 25. The first high-pressure main steam valve; 26. The minimum cooling steam inlet pipeline of the first high- and medium-pressure cylinder; 27. The minimum cooling steam inlet pipeline control and isolation valve group of the first high- and medium-pressure cylinder; 28. The second high-pressure main steam valve; 29. ​​The minimum cooling steam inlet pipeline of the second high- and medium-pressure cylinder; 30. The minimum cooling steam inlet pipeline control and isolation valve group of the second high- and medium-pressure cylinder; 31. The first high-pressure cylinder; 32. The second high-pressure cylinder. DETAILED DESCRIPTION

[0038] The present invention is further described in detail below in conjunction with specific implementation modes, which are intended to explain the present invention rather than to limit it.

[0039] like Figure 1 As shown, the coupled peak-shaving system based on main steam, intermediate exhaust and extraction steam cooling provided by the present invention includes a first conventional unit-type generator set 13 and a second conventional unit-type generator set 14 with basically the same capacity, equipment type and thermal system.

[0040] Specifically, it includes the first high-pressure main steam valve 25, the second high-pressure main steam valve 28, the first high-pressure cylinder 31, the second high-pressure cylinder 32, the first intermediate-pressure cylinder 7, the second intermediate-pressure cylinder 9, the first low-pressure cylinder 8, the second low-pressure cylinder 10, the first condensate pump 11, the second condensate pump 12, the first intermediate-pressure cylinder exhaust control, the isolation valve group 1, the second intermediate-pressure cylinder exhaust control, the isolation valve group 2, the main steam connecting pipe control, the isolation valve group 24, the intermediate-pressure cylinder exhaust connecting pipe control, the isolation valve group 3, the low-pressure feed water connecting pipe control, the isolation valve group 6, the low-pressure cylinder extraction connecting pipe control, the isolation valve group 21, the first high and intermediate pressure cylinder minimum cooling steam inlet pipeline control, the isolation valve group 27, the second high and medium pressure cylinder minimum cooling steam inlet pipeline control and isolation valve group 30, the first low pressure cylinder minimum cooling steam pipeline control and isolation valve group 15, the second low pressure cylinder minimum cooling steam pipeline control and isolation valve group 17, the main steam connecting pipe 23, the medium pressure cylinder exhaust connecting pipe 4, the low pressure feed water connecting pipe 5, the first low pressure cylinder extraction pipe 19, the second low pressure cylinder extraction pipe 20, the low pressure cylinder extraction connecting pipe 22, the first high and medium pressure cylinder minimum cooling steam inlet pipeline 26, the second high and medium pressure cylinder minimum cooling steam inlet pipeline 29, and the first low pressure cylinder minimum cooling steam pipeline 16, the second low pressure cylinder minimum cooling steam pipeline 18;

[0041] The intermediate pressure cylinder exhaust connecting pipe 4 is connected between the exhaust outlet of the first intermediate pressure cylinder 7 and the exhaust outlet of the second intermediate pressure cylinder 9 of the two steam turbines, and the intermediate pressure cylinder exhaust connecting pipe 4 is equipped with an intermediate pressure cylinder exhaust connecting pipe control and isolation valve group 3;

[0042] The main steam connecting pipe 23 is connected between the first high-pressure main steam valve 25 and the second high-pressure main steam valve 28 of the two steam turbines, and the main steam connecting pipe 23 is equipped with a main steam connecting pipe control and isolation valve group 24;

[0043] The first intermediate pressure cylinder exhaust control and isolation valve group 1 is connected between the exhaust port of the first intermediate pressure cylinder 7 and the steam inlet of the first low pressure cylinder 8 of the two steam turbines, and the second intermediate pressure cylinder exhaust control and isolation valve group 2 is connected between the exhaust port of the second intermediate pressure cylinder 9 and the steam inlet of the second low pressure cylinder 10 of the two steam turbines;

[0044] The low-pressure cylinder steam extraction connecting pipe 22 is connected between the first low-pressure cylinder steam extraction pipe 19 and the second low-pressure cylinder steam extraction pipe 20 of the two steam turbines, and the low-pressure cylinder steam extraction connecting pipe 22 is equipped with a low-pressure cylinder steam extraction connecting pipe control and isolation valve group 21;

[0045] The first low-pressure cylinder minimum cooling steam pipeline 16 is connected between the low-pressure cylinder extraction steam connecting pipe 22 and the steam inlet of the first low-pressure cylinder 8, and the second low-pressure cylinder minimum cooling steam pipeline 18 is connected between the low-pressure cylinder extraction steam connecting pipe 22 and the steam inlet of the second low-pressure cylinder 10. The first low-pressure cylinder minimum cooling steam pipeline control and isolation valve group 15 are installed on the first low-pressure cylinder minimum cooling steam pipeline 16, and the second low-pressure cylinder minimum cooling steam pipeline control and isolation valve group 17 are installed on the second low-pressure cylinder minimum cooling steam pipeline 18;

[0046] The first high- and medium-pressure cylinder minimum cooling steam inlet pipeline 26 is connected between the inlet and outlet of the first high-pressure main steam valve 25, and the second high- and medium-pressure cylinder minimum cooling steam inlet pipeline 29 is connected between the inlet and outlet of the second high-pressure main steam valve 28. The first high- and medium-pressure cylinder minimum cooling steam inlet pipeline 26 is equipped with a first high- and medium-pressure cylinder minimum cooling steam inlet pipeline control and isolation valve group 27, and the second high- and medium-pressure cylinder minimum cooling steam inlet pipeline 29 is equipped with a second high- and medium-pressure cylinder minimum cooling steam inlet pipeline control and isolation valve group 30;

[0047] The low-pressure feed water connection pipe 5 is connected between the outlets of the first condensate pump 11 and the second condensate pump 12 of the two steam turbines, and a low-pressure feed water connection pipe control and isolation valve group 6 is installed on the low-pressure feed water connection pipe 5 .

[0048] Preferably, the main steam connecting pipe 23 is equipped with a main steam connecting pipe control and isolation valve group 24 to realize the switching of the deep peak load regulation operation mode of a single unit;

[0049] Preferably, the intermediate pressure cylinder exhaust connecting pipe 4 is equipped with an intermediate pressure cylinder exhaust connecting pipe control and isolation valve group 3 to realize the switching of the deep peak load regulation operation mode of a single unit;

[0050] Preferably, a first intermediate pressure cylinder exhaust control and isolation valve group 1 is installed on the intermediate pressure cylinder exhaust pipe of the first conventional unit-type generator set 13, and the valve group can control the steam intake of the first low pressure cylinder 8, and cooperate with the first high pressure main steam valve 25 to jointly adjust the output of the first conventional unit-type generator set 13;

[0051] Preferably, a second intermediate pressure cylinder exhaust control and isolation valve group 2 is installed on the intermediate pressure cylinder exhaust pipe of the second conventional unit-type generator set 14, and the valve group can control the steam intake of the second low pressure cylinder 10, and cooperate with the second high pressure main steam valve 28 to jointly adjust the output of the second conventional unit-type generator set 14;

[0052] Preferably, the first high-pressure and medium-pressure cylinder minimum cooling steam inlet pipeline 26 of the first conventional unit-type generator set 13 is equipped with a first high-pressure and medium-pressure cylinder minimum cooling steam inlet pipeline control and isolation valve group 27, which can maintain the minimum steam inlet amount of the first high-pressure cylinder 31 to ensure the safe operation of the first high-pressure cylinder 31 and the first medium-pressure cylinder 7;

[0053] Preferably, a second high-pressure and medium-pressure cylinder minimum cooling steam inlet pipeline control and isolation valve group 30 is installed on the second high-pressure and medium-pressure cylinder minimum cooling steam inlet pipeline 29 of the second conventional unit generator set 14, and the valve group can maintain the minimum steam inlet amount of the second high-pressure cylinder 32 to ensure the safe operation of the second high-pressure cylinder 32 and the second medium-pressure cylinder 9;

[0054] Preferably, a low-pressure cylinder extraction steam connection pipe control and isolation valve group 21 is installed on the low-pressure cylinder extraction steam connection pipe 22, which is used to provide the switching of the minimum cooling steam for the first low-pressure cylinder 8 and the second low-pressure cylinder 10 during the deep peak regulation process;

[0055] Preferably, a first low-pressure cylinder minimum cooling steam pipeline control and isolation valve group 15 is installed on the first low-pressure cylinder minimum cooling steam pipeline 16 of the first conventional unit-type generator set 13, and the valve group can maintain the minimum steam intake of the first low-pressure cylinder 8 to ensure the safe operation of the first low-pressure cylinder 8;

[0056] Preferably, the second low-pressure cylinder minimum cooling steam pipeline 18 of the second conventional unit generator set 14 is equipped with a first low-pressure cylinder minimum cooling steam pipeline control and isolation valve group 17, which can maintain the minimum steam intake of the second low-pressure cylinder 10 to ensure the safe operation of the second low-pressure cylinder 10;

[0057] Preferably, a low-pressure water supply connecting pipe control and isolation valve group 6 is installed on the low-pressure water supply connecting pipe 5, which is used to adjust the low-pressure water supply flow of the two units during the deep peak regulation process to maintain the deaerator water level stable.

[0058] The operating method of the coupled peak-shaving system based on main steam, intermediate exhaust and extraction steam cooling provided by the present invention comprises the following steps:

[0059] Step 1, the first conventional unit-type generator set 13 and the second conventional unit-type generator set 14 operate normally, and the first high-pressure main steam valve 25 and the second high-pressure main steam valve 28 remain in normal operating state; the main steam connecting pipe 23 is controlled by the main steam connecting pipe, and the isolation valve group 24 is in a closed state; the medium-pressure cylinder exhaust connecting pipe 4 is controlled by the medium-pressure cylinder exhaust connecting pipe, and the isolation valve group 3 is in a closed state; the low-pressure cylinder extraction connecting pipe 22 is controlled by the low-pressure cylinder extraction connecting pipe, and the isolation valve group 21 is in a closed state; the low-pressure water supply connecting pipe 5 is controlled by the low-pressure water supply connecting pipe, and the isolation valve group 6 is in a closed state; the first medium-pressure cylinder exhaust control, isolation valve group 6 of the first conventional unit-type generator set 13 1 is in the open state; the first high- and medium-pressure cylinder minimum cooling steam inlet pipeline control and isolation valve group 27 of the first conventional unit-based generator set 13 are in the closed state; the first low-pressure cylinder minimum cooling steam pipeline control and isolation valve group 15 of the first conventional unit-based generator set 13 are in the closed state; the second medium-pressure cylinder exhaust steam control and isolation valve group 2 of the second conventional unit-based generator set 14 are in the open state; the second high- and medium-pressure cylinder minimum cooling steam inlet pipeline control and isolation valve group 30 of the second conventional unit-based generator set 14 are in the closed state; the second low-pressure cylinder minimum cooling steam pipeline control and isolation valve group 17 of the second conventional unit-based generator set 14 are in the closed state;

[0060] Step 2, the main steam connecting pipe 23 is controlled, and the isolation valve group 24 is opened; the medium-pressure cylinder exhaust connecting pipe 4 of the medium-pressure cylinder exhaust connecting pipe is controlled, and the isolation valve group 3 is opened; the first high- and medium-pressure cylinder minimum cooling steam inlet pipeline of the first conventional unit-based generator set 13 is controlled, and the isolation valve group 27 is opened; the first low-pressure cylinder minimum cooling steam pipeline of the first conventional unit-based generator set 13 is controlled, and the isolation valve group 15 is opened; the low-pressure cylinder extraction connecting pipe 22 of the low-pressure cylinder extraction connecting pipe is controlled, and the isolation valve group 21 is opened; the first high-pressure main steam valve 25 of the first conventional unit-based generator set 13 is slowly closed; the first medium-pressure cylinder exhaust control of the first conventional unit-based generator set 13, and the isolation valve group 1 are slowly closed; the low-pressure water supply connecting pipe 5 of the low-pressure water supply connecting pipe is controlled, and the isolation valve group 6 is slowly opened; maintain the water level of the deaerator of the first conventional unit-based generator set 13 stable; realize the deep peak-shaving operation of the first conventional unit-based generator set 13;

[0061] Step 3, the main steam connecting pipe 23 is controlled by the main steam connecting pipe, and the isolation valve group 24 is kept open; the medium-pressure cylinder exhaust connecting pipe 4 of the medium-pressure cylinder exhaust connecting pipe is controlled by the isolation valve group 3 and is kept open; the first high-pressure main steam valve 25 of the first conventional unit-type generator set 13 is slowly opened; the first medium-pressure cylinder exhaust control and isolation valve group 1 of the first conventional unit-type generator set 13 are slowly opened; the first high- and medium-pressure cylinder minimum cooling steam inlet pipeline control and isolation valve group 27 of the first conventional unit-type generator set 13 are slowly closed; the first low-pressure cylinder minimum cooling steam pipeline control and isolation valve group 15 of the first conventional unit-type generator set 13 are slowly closed. Close; open the second high- and medium-pressure cylinder minimum cooling steam inlet pipeline control and isolation valve group 30 of the second conventional unit-type generator set 14; open the second low-pressure cylinder minimum cooling steam pipeline control and isolation valve group 17 of the second conventional unit-type generator set 14; slowly close the second high-pressure main steam valve 28 of the second conventional unit-type generator set 14; slowly close the second medium-pressure cylinder exhaust control and isolation valve group 2 of the second conventional unit-type generator set 14; maintain the low-pressure feed water control and isolation valve group 6 open; maintain the water level of the deaerator of the second conventional unit-type generator set 14 stable; realize the deep peak-shaving operation of the second conventional unit-type generator set 14.

[0062] The above description is only a preferred specific implementation method of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation or application to multiple units made by using the contents of the present invention specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A coupled peak load regulation system based on main steam, intermediate exhaust and extraction steam cooling, characterized in that: It comprises a first conventional unit-type generator set (13) and a second conventional unit-type generator set (14); Specifically, it includes a first high-pressure main steam valve (25), a second high-pressure main steam valve (28), a first high-pressure cylinder (31), a second high-pressure cylinder (32), a first intermediate-pressure cylinder (7), a second intermediate-pressure cylinder (9), a first low-pressure cylinder (8), a second low-pressure cylinder (10), a first condensate pump (11), a second condensate pump (12), a first intermediate-pressure cylinder exhaust control and an isolation valve group (1), a second intermediate-pressure cylinder exhaust control and an isolation valve group (2), a main steam connecting pipe control and an isolation valve group (24), an intermediate-pressure cylinder exhaust connecting pipe control and an isolation valve group (3), a low-pressure feedwater connecting pipe control and an isolation valve group (6), a low-pressure cylinder extraction connecting pipe control and an isolation valve group (21), a first high-pressure and intermediate-pressure cylinder minimum cooling steam inlet pipe control and an isolation valve group Valve group (27), second high and medium pressure cylinder minimum cooling steam inlet pipeline control, isolation valve group (30), first low pressure cylinder minimum cooling steam pipeline control, isolation valve group (15), second low pressure cylinder minimum cooling steam pipeline control, isolation valve group (17), main steam connecting pipe (23), medium pressure cylinder exhaust connecting pipe (4), low pressure feed water connecting pipe (5), low pressure cylinder extraction connecting pipe (22), first low pressure cylinder extraction pipe (19), second low pressure cylinder extraction pipe (20), first high and medium pressure cylinder minimum cooling steam inlet pipeline (26), second high and medium pressure cylinder minimum cooling steam inlet pipeline (29), first low pressure cylinder minimum cooling steam pipeline (16), second low pressure cylinder minimum cooling steam pipeline (18); The intermediate pressure cylinder exhaust connecting pipe (4) is connected between the exhaust outlet of the first intermediate pressure cylinder (7) and the exhaust outlet of the second intermediate pressure cylinder (9) of the two steam turbines, and the intermediate pressure cylinder exhaust connecting pipe (4) is equipped with an intermediate pressure cylinder exhaust connecting pipe control and isolation valve group (3); A main steam connecting pipe (23) is connected between the steam inlets of the first high-pressure main steam valves (25) and the second high-pressure main steam valves (28) of the two steam turbines, and a main steam connecting pipe control and isolation valve group (24) is installed on the main steam connecting pipe (23); The first intermediate pressure cylinder exhaust control and isolation valve group (1) is connected between the exhaust port of the first intermediate pressure cylinder (7) and the steam inlet of the first low pressure cylinder (8), and the second intermediate pressure cylinder exhaust control and isolation valve group (2) is connected between the exhaust port of the second intermediate pressure cylinder (9) and the steam inlet of the second low pressure cylinder (10); A low-pressure cylinder steam extraction connecting pipe (22) is connected between a first low-pressure cylinder steam extraction pipe (19) and a second low-pressure cylinder steam extraction pipe (20) of two steam turbines, and a low-pressure cylinder steam extraction connecting pipe control and isolation valve group (21) is installed on the low-pressure cylinder steam extraction connecting pipe (22); The first low-pressure cylinder minimum cooling steam pipeline (16) is connected between the low-pressure cylinder extraction steam connecting pipe (22) and the steam inlet of the first low-pressure cylinder (8), the second low-pressure cylinder minimum cooling steam pipeline (18) is connected between the low-pressure cylinder extraction steam connecting pipe (22) and the steam inlet of the second low-pressure cylinder (10), the first low-pressure cylinder minimum cooling steam pipeline control and isolation valve group (15) is installed on the first low-pressure cylinder minimum cooling steam pipeline (16), and the second low-pressure cylinder minimum cooling steam pipeline control and isolation valve group (17) is installed on the second low-pressure cylinder minimum cooling steam pipeline (18); The first high- and medium-pressure cylinder minimum cooling steam inlet pipeline (26) is connected between the inlet and outlet of the first high-pressure main steam valve (25), the second high- and medium-pressure cylinder minimum cooling steam inlet pipeline (29) is connected between the inlet and outlet of the second high-pressure main steam valve (28), the first high- and medium-pressure cylinder minimum cooling steam inlet pipeline control and isolation valve group (27) is installed on the first high- and medium-pressure cylinder minimum cooling steam inlet pipeline (26), and the second high- and medium-pressure cylinder minimum cooling steam inlet pipeline control and isolation valve group (30) is installed on the second high- and medium-pressure cylinder minimum cooling steam inlet pipeline (29); The low-pressure water supply connecting pipe (5) is connected between the outlets of the first condensate pumps (11) and the outlets of the second condensate pumps (12) of the two steam turbines, and a low-pressure water supply connecting pipe control and isolation valve group (6) is installed on the low-pressure water supply connecting pipe (5).

2. The coupled peak load regulation system based on main steam, intermediate exhaust and extraction steam cooling according to claim 1 is characterized in that: The first conventional unit-type generator set (13) and the second conventional unit-type generator set (14) have the same power generation capability and equivalent capacity, and the same equipment type and thermal system design.

3. The coupled peak load regulation system based on main steam, intermediate exhaust and extraction steam cooling according to claim 1 is characterized in that: The operating status of the first conventional unit-type generator set (13) and the second conventional unit-type generator set (14) is that both boilers and both steam turbines are in an operating state.

4. The coupled peak load regulation system based on main steam, intermediate exhaust and extraction steam cooling according to claim 1 is characterized in that: The main steam of the first conventional unit-type generator set (13) can enter the second high-pressure cylinder (32) of the second conventional unit-type generator set (14) through the main steam connecting pipe (23) to perform work; The main steam of the second conventional unit-type generator set (14) can enter the first high-pressure cylinder (31) of the first conventional unit-type generator set (13) through the main steam connecting pipe (23) to perform work.

5. The coupled peak load regulation system based on main steam, intermediate exhaust and extraction steam cooling according to claim 1 is characterized in that: When the second high-pressure main steam valve (28) of the second conventional unit-type generator set (14) is closed, the main steam of the second conventional unit-type generator set (14) can enter the second high-pressure cylinder (32) and the second medium-pressure cylinder (9) through the second high- and medium-pressure cylinder minimum cooling steam inlet pipeline (29), thereby ensuring the safe operation of the second high-pressure cylinder (32) and the second medium-pressure cylinder (9); When the first high-pressure main steam valve (25) of the first conventional unit-type generator set (13) is closed, the main steam of the first conventional unit-type generator set (13) can enter the first high-pressure cylinder (31) and the first medium-pressure cylinder (7) via the first high- and medium-pressure cylinder minimum cooling steam inlet pipeline (26), thereby ensuring the safe operation of the first high-pressure cylinder (31) and the first medium-pressure cylinder (7).

6. The coupled peak load regulation system based on main steam, intermediate exhaust and extraction steam cooling according to claim 1 is characterized in that: The exhaust steam of the first intermediate pressure cylinder (7) of the first conventional unit-type generator set (13) can enter the second low pressure cylinder (10) of the second conventional unit-type generator set (14) through the intermediate pressure cylinder exhaust communication pipe (4) to perform work; The exhaust steam of the second intermediate pressure cylinder (9) of the second conventional unit-type generator set (14) can enter the first low pressure cylinder (8) of the first conventional unit-type generator set (13) through the intermediate pressure cylinder exhaust communication pipe (4) to perform work.

7. The coupled peak load regulation system based on main steam, intermediate exhaust and extraction steam cooling according to claim 1 is characterized in that: Condensate at the outlet of the first condensate pump (11) of the first conventional unit-type generator set (13) enters the low-pressure water supply system of the second conventional unit-type generator set (14) through the low-pressure water supply connecting pipe (5) to maintain the water level of the deaerator of the second conventional unit-type generator set (14) stable; Condensate at the outlet of the second condensate pump (12) of the second conventional unit-type generator set (14) enters the low-pressure water supply system of the first conventional unit-type generator set (13) through the low-pressure water supply connecting pipe (5) to maintain the stability of the deaerator water level of the first conventional unit-type generator set (13).

8. The coupled peak load regulation system based on main steam, intermediate exhaust and extraction steam cooling according to claim 1 is characterized in that: When the second medium-pressure cylinder exhaust steam control and isolation valve group (2) of the second conventional unit-type generator set (14) are closed, the low-pressure cylinder extraction steam of the first conventional unit-type generator set (13) can enter the second low-pressure cylinder (10) to cool the low-pressure cylinder via the first low-pressure cylinder extraction steam pipe (19), the low-pressure cylinder extraction steam communication pipe (22) and the second low-pressure cylinder minimum cooling steam pipeline (18), thereby ensuring the safe operation of the second low-pressure cylinder (10); When the first medium-pressure cylinder exhaust control and isolation valve group (1) of the first conventional unit-type generator set (13) is closed, the low-pressure cylinder extraction steam of the second conventional unit-type generator set (14) can enter the first low-pressure cylinder (8) through the second low-pressure cylinder extraction pipe (20), the low-pressure cylinder extraction connecting pipe (22) and the first low-pressure cylinder minimum cooling steam pipeline (16) to cool the low-pressure cylinder, thereby ensuring the safe operation of the first low-pressure cylinder (8).

9. The operation method of the coupled peak load regulation system based on main steam, intermediate exhaust and extraction steam cooling is characterized in that: The method is based on the coupled peak-shaving system based on main steam, intermediate exhaust and extraction steam cooling according to any one of claims 1 to 8, and comprises the following steps: Step 1: The first conventional unit-type generator set (13) and the second conventional unit-type generator set (14) operate normally, and the first high-pressure main steam valve (25) and the second high-pressure main steam valve (28) maintain a normal operating state; the main steam connecting pipe (23) is controlled by the main steam connecting pipe and the isolation valve group (24) are in a closed state; the intermediate pressure cylinder exhaust connecting pipe (4) is controlled by the intermediate pressure cylinder exhaust connecting pipe and the isolation valve group (3) are in a closed state; the low pressure cylinder extraction connecting pipe (22) is controlled by the low pressure cylinder extraction connecting pipe and the isolation valve group (21) are in a closed state; The low-pressure water supply connecting pipe (5) is in a closed state; the low-pressure water supply connecting pipe control and the isolation valve group (6) are in a closed state; the first medium-pressure cylinder exhaust control and the isolation valve group (1) of the first conventional unit-based generator set (13) are in an open state; the first high- and medium-pressure cylinder minimum cooling steam inlet pipeline control and the isolation valve group (27) of the first conventional unit-based generator set (13) are in a closed state; the first low-pressure cylinder minimum cooling steam pipeline control and the isolation valve group (15) of the first conventional unit-based generator set (13) are in a closed state; The second intermediate pressure cylinder exhaust steam control and isolation valve group (2) of the second conventional unit-type generator set (14) is in an open state; The second high- and medium-pressure cylinder minimum cooling steam inlet pipeline control and isolation valve group (30) of the second conventional unit-based generator set (14) are in a closed state; the second low-pressure cylinder minimum cooling steam pipeline control and isolation valve group (17) of the second conventional unit-based generator set (14) are in a closed state; Step 2, the main steam connecting pipe (23) is controlled by the isolation valve group (24) to be opened; the intermediate pressure cylinder exhaust connecting pipe (4) is controlled by the isolation valve group (3) to be opened; the first high and intermediate pressure cylinder minimum cooling steam inlet pipeline of the first conventional unit-type generator set (13) is controlled by the isolation valve group (27) to be opened; the first low pressure cylinder minimum cooling steam pipeline of the first conventional unit-type generator set (13) is controlled by the isolation valve group (15) to be opened; the low pressure cylinder extraction connecting pipe (22) is controlled by the isolation valve group (21) to be opened; The first high-pressure main steam valve (25) of the first conventional unit-type generator set (13) is slowly closed; the first medium-pressure cylinder exhaust steam control and isolation valve group (1) of the first conventional unit-type generator set (13) are slowly closed; the low-pressure water supply connection pipe control and isolation valve group (6) of the low-pressure water supply connection pipe (5) are slowly opened; the water level of the deaerator of the first conventional unit-type generator set (13) is maintained stable; and deep peak-shaving operation of the first conventional unit-type generator set (13) is achieved; Step 3: The main steam connecting pipe (23) is controlled and the isolation valve group (24) is kept open; the intermediate pressure cylinder exhaust connecting pipe (4) is controlled and the isolation valve group (3) is kept open; the first high pressure main steam valve (25) of the first conventional unit generator set (13) is slowly opened; The first medium-pressure cylinder exhaust steam control and isolation valve group (1) of the first conventional unit-type generator set (13) are slowly opened; the first high- and medium-pressure cylinder minimum cooling steam inlet pipeline control and isolation valve group (27) of the first conventional unit-type generator set (13) are slowly closed; the first low-pressure cylinder minimum cooling steam pipeline control and isolation valve group (15) of the first conventional unit-type generator set (13) are slowly closed; The second high-pressure and medium-pressure cylinder minimum cooling steam inlet pipeline control and isolation valve group (30) of the second conventional unit-type generator set (14) are opened; The second low-pressure cylinder minimum cooling steam pipeline control and isolation valve group (17) of the second conventional unit-type generator set (14) are opened; The second high-pressure main steam valve (28) of the second conventional unit-type generator set (14) is slowly closed; The second medium-pressure cylinder exhaust steam control and isolation valve group (2) of the second conventional unit-type generator set (14) are slowly closed; the low-pressure feed water control and isolation valve group (6) are kept open; the water level of the deaerator of the second conventional unit-type generator set (14) is maintained stable; and the deep peak-shaving operation of the second conventional unit-type generator set (14) is achieved.

10. The method for operating a coupled peak load regulation system based on main steam, intermediate exhaust and extraction steam cooling according to claim 9, characterized in that: The first conventional unit-type generator set (13) and the second conventional unit-type generator set (14) are both in a grid-connected power generation state, and any one of the generator sets can participate in deep peak regulation at any time; Alternatively, the operating states of the first conventional unit-based generator set (13) and the second conventional unit-based generator set (14) can be switched to each other.

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