Coupling peak-shaving system between units based on middle row and its cooling and operation method thereof

Abstract

The present invention discloses a coupled peak-shaving system based on intermediate row and cooling between units and an operation method thereof, the system comprising a first conventional unit-based generator set (13) and a second conventional unit-based generator set (14); the first conventional unit-based generator set (13) comprises a first intermediate pressure cylinder (7), a first low pressure cylinder (8), a first condensate pump (11) and a first intermediate pressure cylinder exhaust steam control and isolation valve group (1), and the second conventional unit-based generator set (14) comprises a second intermediate pressure cylinder (9), a second low pressure cylinder (10), a second condensate pump (12) and a second intermediate pressure cylinder exhaust steam control and isolation valve group (2); the operation method realizes free switching between the first conventional unit-based generator set (13) and the second conventional unit-based generator set (14). The present invention can improve the deep peak-shaving capability of the unit and increase the flexibility of the unit operation without technical modification on 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 between units based on an intermediate row and its 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 between units based on the middle row and its 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 between units based on the middle row and its cooling, including a first conventional unit-based generator set and a second conventional unit-based generator set;

[0007] The first conventional unit-type generator set includes a first intermediate pressure cylinder, a first low pressure cylinder, a first condensate pump, and a first intermediate pressure cylinder exhaust control and isolation valve group, and the second conventional unit-type generator set includes a second intermediate pressure cylinder, a second low pressure cylinder, a second condensate pump, and a second intermediate pressure cylinder exhaust control and isolation valve group;

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

[0009] A 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 a 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;

[0010] The first low-pressure cylinder minimum cooling steam pipeline is also connected between the inlet and outlet of the first intermediate-pressure cylinder exhaust steam control and isolation valve group, and the second low-pressure cylinder minimum cooling steam pipeline is also connected between the inlet and outlet of the second intermediate-pressure cylinder exhaust steam control and isolation valve group. The first low-pressure cylinder minimum cooling steam pipeline is equipped with the first low-pressure cylinder minimum cooling steam pipeline control and isolation valve group, and the second low-pressure cylinder minimum cooling steam pipeline is equipped with the second low-pressure cylinder minimum cooling steam pipeline control and isolation valve group;

[0011] A low-pressure water supply connecting pipe is connected between the outlets of the first condensate pumps and the second condensate pumps of the two steam turbines, and a low-pressure water supply connecting pipe control and isolation valve group is installed on the low-pressure water supply connecting pipe.

[0012] 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.

[0013] 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.

[0014] 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;

[0015] 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.

[0016] 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 can enter 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;

[0017] The condensate at the outlet of the second condensate pump of the second conventional unit-type generator set can enter 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.

[0018] A further improvement of the present invention is that when the second intermediate pressure cylinder exhaust control and isolation valve group of the second conventional unit generator set is closed, the low pressure cylinder extraction steam of the first conventional unit generator set can enter the second low pressure cylinder through the first low pressure cylinder extraction pipe, the low pressure cylinder extraction connecting pipe and the second low pressure cylinder minimum cooling steam pipeline to cool the low pressure cylinder, thereby ensuring the safe operation of the low pressure cylinder.

[0019] A further improvement of the present invention is that when the first intermediate pressure cylinder exhaust control and isolation valve group of the first conventional unit-type generator set is closed, the low pressure cylinder extraction steam of the second conventional unit-type 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 low pressure cylinder.

[0020] The method for operating the coupled peak-shaving system between units based on the middle row and its cooling is based on the coupled peak-shaving system between units based on the middle row and its cooling, and comprises the following steps:

[0021] Step 1, the first conventional unit-type generator set and the second conventional unit-type generator set operate normally, the first medium-pressure cylinder exhaust control and isolation valve group of the first conventional unit-type generator set are in an open 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 a closed state; the second medium-pressure cylinder exhaust control and isolation valve group of the second conventional unit-type generator set are in an open 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 a closed state; the medium-pressure cylinder exhaust communication pipe, the medium-pressure cylinder exhaust communication pipe control, and the isolation valve group are in a closed state; the low-pressure water supply communication pipe control and isolation valve group of the low-pressure water supply communication pipe are in a closed state;

[0022] Step 2: The intermediate pressure cylinder exhaust pipe of the intermediate pressure cylinder exhaust pipe 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 first intermediate pressure cylinder exhaust pipe of the first conventional unit-based generator set is controlled, and the isolation valve group is slowly closed; the low pressure water supply pipe of the low pressure water supply 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 operation of the first conventional unit-based generator set is realized;

[0023] Step 3, the intermediate pressure cylinder exhaust pipe control and isolation valve group of the intermediate pressure cylinder exhaust pipe are kept open; the first intermediate pressure cylinder exhaust control and isolation valve group of the first conventional unit generator set are slowly opened; the second low pressure cylinder minimum cooling steam pipeline control and isolation valve group of the second conventional unit generator set are opened; the second intermediate pressure cylinder exhaust control and isolation valve group are slowly closed; the low pressure feed water control and isolation valve group are kept open; the water level of the deaerator of the second conventional unit generator set is maintained stable; and the deep peak regulation operation of the second conventional unit generator set is realized.

[0024] 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.

[0025] A further improvement of the present invention is that 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.

[0026] Compared with the prior art, the present invention has at least the following beneficial technical effects:

[0027] The present invention realizes the switching of deep peak-shaving operation mode of any unit by adding medium-pressure cylinder exhaust connecting pipe, low-pressure water supply connecting pipe and low-pressure cylinder minimum cooling steam pipeline; when a unit is in deep peak-shaving operation, its low-pressure cylinder steam inlet flow can be reduced to the minimum, at which time the low-pressure cylinder 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 steam inlet volume of the low-pressure cylinder of one unit can be transported to the low-pressure cylinder of 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

[0028] Figure 1 It is a schematic diagram of the thermal system of the coupled peak-shaving system based on the middle row and its cooling between units described in the example of the present invention.

[0029] Description of reference numerals:

[0030] 1. Exhaust control and isolation valve group of the first intermediate pressure cylinder; 2. Exhaust control and isolation valve group of the second intermediate pressure cylinder; 3. Exhaust connecting pipe control and isolation valve group of the intermediate pressure cylinder; 4. Exhaust connecting pipe of the intermediate pressure cylinder; 5. Low-pressure water supply connecting pipe; 6. Low-pressure water supply connecting pipe control and 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. Minimum cooling steam pipeline control and isolation valve group of the first low-pressure cylinder; 17. Minimum cooling steam pipeline control and isolation valve group of the second low-pressure cylinder; 16. Minimum cooling steam pipeline of the first low-pressure cylinder; 18. Minimum cooling steam pipeline of the second low-pressure cylinder. DETAILED DESCRIPTION

[0031] 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.

[0032] like Figure 1As shown, the coupled peak-shaving system between units based on the middle row and its 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.

[0033] The first conventional unit-type generator set 13 includes a first intermediate-pressure cylinder 7, a first low-pressure cylinder 8, a first condensate pump 11 and a first intermediate-pressure cylinder exhaust control and isolation valve group 1, and the second conventional unit-type generator set 14 includes a second intermediate-pressure cylinder 9, a second low-pressure cylinder 10, a second condensate pump 12 and a second intermediate-pressure cylinder exhaust control and isolation valve group 2; 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 are connected through an intermediate-pressure cylinder exhaust connecting pipe 4, and an intermediate-pressure cylinder exhaust connecting pipe control and isolation valve group 3 is installed on the intermediate-pressure cylinder exhaust connecting pipe 4; 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 exhaust port of the second intermediate-pressure cylinder 9 and the steam inlet of the second low-pressure cylinder 10 are connected There is a second intermediate-pressure cylinder exhaust control and isolation valve group 2; a first low-pressure cylinder minimum cooling steam pipeline 16 is also connected between the inlet and outlet of the first intermediate-pressure cylinder exhaust control and isolation valve group 1, and a second low-pressure cylinder minimum cooling steam pipeline 18 is also connected between the inlet and outlet of the second intermediate-pressure cylinder exhaust control and isolation valve group 2; 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, and a 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; a low-pressure feed water connecting pipe 5 is connected between the outlet of the first condensate pump 11 and the outlet of the second condensate pump 12 of the two steam turbines, and a low-pressure feed water connecting pipe control and isolation valve group 6 is installed on the low-pressure feed water connecting pipe 5.

[0034] Preferably, a medium-pressure cylinder exhaust connecting pipe control and isolation valve group 3 is installed on the medium-pressure cylinder exhaust connecting pipe 4 to realize the switching of the deep peak-shaving operation mode of a single unit;

[0035] 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 adjust the output of the first low-pressure cylinder 8 of the first conventional unit-type generator set 13;

[0036] 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 adjust the output of the second low pressure cylinder 10 of the second conventional unit-type generator set 14;

[0037] 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 of the first conventional unit-type generator set 13 to ensure the safe operation of the first low-pressure cylinder 8;

[0038] Preferably, a 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 of the second conventional unit-type generator set 14, and the valve group can maintain the minimum steam intake amount of the second low-pressure cylinder 10 of the second conventional unit-type generator set 14 to ensure the safe operation of the second low-pressure cylinder 10;

[0039] 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.

[0040] The operating method of the coupled peak-shaving system between units based on the middle row and its cooling provided by the present invention comprises the following steps:

[0041] Step 1, the first conventional unit-type generator set 13 and the second conventional unit-type generator set 14 operate normally, the first medium-pressure cylinder exhaust control and isolation valve group 1 of the first conventional unit-type generator set 13 are in an open state; 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 in a closed state; the second medium-pressure cylinder exhaust control and isolation valve group 2 of the second conventional unit-type generator set 14 are in an open state; 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 in a closed state; the medium-pressure cylinder exhaust communication pipe 4, the medium-pressure cylinder exhaust communication pipe control, and the isolation valve group 3 are in a closed state; the low-pressure water supply communication pipe control and isolation valve group 6 of the low-pressure water supply communication pipe 5 are in a closed state;

[0042] Step 2, the intermediate pressure cylinder exhaust pipe 4 of the intermediate pressure cylinder exhaust pipe is controlled, and the isolation valve group 3 is opened; the first low pressure cylinder minimum cooling steam pipeline of the first conventional unit generator set 13 is controlled, and the isolation valve group 15 is opened; the first intermediate pressure cylinder exhaust pipe of the first conventional unit generator set 13 is controlled, and the isolation valve group 1 is slowly closed; the low pressure water supply pipe 5 of the low pressure water supply pipe is controlled, and the isolation valve group 6 is slowly opened; the water level of the deaerator of the first conventional unit generator set 13 is maintained stable; and the deep peak load operation of the first conventional unit generator set 13 is realized;

[0043] Step 3, the intermediate pressure cylinder exhaust communication pipe control and isolation valve group of the intermediate pressure cylinder exhaust communication pipe 4 are maintained open; the first intermediate pressure cylinder exhaust control and isolation valve group 1 of the first conventional unit generator set 13 are slowly opened; the second low pressure cylinder minimum cooling steam pipeline control and isolation valve group 17 of the second conventional unit generator set 14 are opened; the second intermediate pressure cylinder exhaust control and isolation valve group 2 are slowly closed; the low pressure feed water control and isolation valve group 6 are maintained open; the water level of the deaerator of the second conventional unit generator set 14 is maintained stable; and the deep peak regulation operation of the second conventional unit generator set 14 is realized.

[0044] 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. The coupled peak load regulation system between units based on the middle row and its cooling is characterized by: It comprises a first conventional unit-type generator set (13) and a second conventional unit-type generator set (14); The first conventional unit-type generator set (13) includes a first intermediate-pressure cylinder (7), a first low-pressure cylinder (8), a first condensate pump (11) and a first intermediate-pressure cylinder exhaust steam control and isolation valve group (1), and the second conventional unit-type generator set (14) includes a second intermediate-pressure cylinder (9), a second low-pressure cylinder (10), a second condensate pump (12) and a second intermediate-pressure cylinder exhaust steam control and isolation valve group (2); The exhaust steam outlets of the first intermediate pressure cylinders (7) and the exhaust steam outlets of the second intermediate pressure cylinders (9) of the two steam turbines are connected via an intermediate pressure cylinder exhaust steam connecting pipe (4), and an intermediate pressure cylinder exhaust steam connecting pipe control and isolation valve group (3) is installed on the intermediate pressure cylinder exhaust steam connecting pipe (4); A 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 a 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 first low-pressure cylinder minimum cooling steam pipeline (16) is also connected between the inlet and outlet of the first intermediate-pressure cylinder exhaust steam control and isolation valve group (1), a second low-pressure cylinder minimum cooling steam pipeline (18) is also connected between the inlet and outlet of the second intermediate-pressure cylinder exhaust steam control and isolation valve group (2), 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), and a 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); A 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 between units based on the middle row and its 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 between units based on the middle row and its 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 between units based on the middle row and its cooling according to claim 1, 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.

5. The coupled peak load regulation system between units based on the middle row and its cooling according to claim 1, characterized in that: Condensate at the outlet of the first condensate pump (11) of the first conventional unit-type generator set (13) can enter 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) can enter 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).

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

7. The coupled peak load regulation system between units based on the middle row and its cooling according to claim 1, characterized in that: When the first medium-pressure cylinder exhaust steam control and isolation valve group (1) of the first conventional unit-type generator set (13) are 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 steam pipe (20), the low-pressure cylinder extraction steam 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 low-pressure cylinder.

8. The method for operating the coupled peak load regulation system between units based on the middle row and its cooling is characterized in that: The method is based on the coupled peak-shaving system between units based on the middle row and its cooling according to any one of claims 1 to 7, and comprises the following steps: Step 1: The first conventional unit-based generator set (13) and the second conventional unit-based generator set (14) operate normally, and the first intermediate pressure cylinder exhaust steam control and isolation valve group (1) of the first conventional unit-based generator set (13) is in an open state; 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 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 low-pressure cylinder minimum cooling steam pipeline control and isolation valve group (17) of the second conventional unit-type generator set (14) are in a closed state; the medium-pressure cylinder exhaust steam connecting pipe (4), the medium-pressure cylinder exhaust steam connecting pipe control and the isolation valve group (3) are in a closed state; the low-pressure water supply connecting pipe (5) and the isolation valve group (6) are in a closed state; Step 2: the intermediate pressure cylinder exhaust communication pipe (4) of the intermediate pressure cylinder exhaust communication pipe is controlled and the isolation valve group (3) is opened; the first low pressure cylinder minimum cooling steam pipeline of the first conventional unit generator set (13) is controlled and the isolation valve group (15) is opened; The first medium-pressure cylinder exhaust steam control and the isolation valve group (1) of the first conventional unit-type generator set (13) are slowly closed; the low-pressure water supply connecting pipe control and the isolation valve group (6) of the low-pressure water supply connecting 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 intermediate pressure cylinder exhaust communication pipe control and isolation valve group of the intermediate pressure cylinder exhaust communication pipe (4) are kept open; the first intermediate pressure cylinder exhaust control and isolation valve group (1) of the first conventional unit-type generator set (13) are slowly 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 medium-pressure cylinder exhaust steam control and isolation valve group (2) 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.

9. The method for operating a coupled peak-shaving system based on middle row and its cooling between units according to claim 8, 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.

10. The method for operating a coupled peak-shaving system based on middle rows and their cooling between units according to claim 8, characterized in that: The operating states of the first conventional unit-based generator set (13) and the second conventional unit-based generator set (14) can be switched with each other.

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