CN220815770U - Industrial steam supply thermodynamic system for deep peak regulation of coal-fired steam turbine generator unit - Google Patents

Abstract

The utility model relates to the field of thermal power generation, in particular to an industrial steam supply thermodynamic system for deep peak regulation of a coal-fired steam turbine generator unit, which comprises a back press A, a bypass machine, a back press B, related steam inlet steam exhaust valves, pipelines and the like, wherein the back press A and the bypass machine are connected through a coupling, steam inlet pipelines and/or steam exhaust pipelines between the back press A and the bypass machine are connected through check valves, the steam flow direction of the steam inlet check valve flows from the bypass machine to the back press A, the steam flow direction of the steam exhaust check valve flows from the back press A to the bypass machine, and the steam exhaust pipeline of the bypass machine is connected with the steam inlet pipeline of the back press B, the industrial steam supply pipeline and a main machine reheat cold section. The utility model can reasonably and stepwise utilize the steam energy of the thermal power plant for industrial steam supply, and is not limited by the deep peak regulation of the unit; the operation of the small machine can not be influenced under the condition that the requirements of industrial steam supply users are interrupted; the small machine can achieve higher internal efficiency under the condition of smaller industrial steam supply flow.

Description

Industrial steam supply thermodynamic system for deep peak regulation of coal-fired steam turbine generator unit

Technical Field

The utility model relates to the field of thermal power generation, in particular to an industrial steam supply thermodynamic system for deep peak regulation of a coal-fired steam turbine generator unit (hereinafter referred to as a unit), wherein a small steam turbine can be used for directly driving an auxiliary machine or a steam-electric double-driving system and also can be used for driving a generator to feed back to a station power system, and the industrial steam supply thermodynamic system is suitable for providing steam with suitable parameters for industrial users under the deep peak regulation condition of a thermal power plant, in particular to steam for an industrial park.

Background

In national economy production activities, enterprises such as chemical industry, papermaking, pharmacy, textile printing and dyeing, foods, building materials and the like need a large amount of steam, many enterprises are realized by arranging coal-fired industrial boilers, the requirements on environmental protection and energy consumption are increasingly strict, the steam is generated by the coal-fired industrial boilers in a steam supply mode, but the cost is higher, in the peripheral area of a thermal power plant, the steam supply to industrial users through the thermal power plant becomes a good choice, the steam with certain parameters is directly supplied to the outside from a boiler or a steam turbine (hereinafter referred to as a host), or the steam with proper parameters is provided for users after the functional quantity step utilization by a small steam turbine (hereinafter referred to as a small machine), wherein the small machine is provided with a back pressure type small machine (hereinafter referred to as a back pressure machine), a steam extraction condensing type small machine and a steam extraction back pressure type small machine, and the current new energy is connected into a power grid in a large quantity, the peak regulating amplitude of the thermal power unit is higher, the steam extraction pressure of the main machine is too low, the steam supply pressure required by the industrial users is constant, the steam extraction pressure required by the main machine is required to be reduced, the main machine pressure is not to be constant, the back pressure is reduced, the steam pressure is not required to be reduced, and the main machine pressure is not normally supplied to the main machine is required to the main machine, and the steam is not normally supplied to the main machine, and the steam is not required to the main machine is not to be supplied to the normal, and the main machine has been required to the normal pressure is not normally, and the pressure is required to the main machine has been reduced.

Disclosure of Invention

Aiming at the problem that the low-load state of the thermal power plant unit can not meet the requirement of industrial user steam consumption, the utility model provides an industrial steam supply thermodynamic system for deep peak regulation of a coal-fired steam turbine generator unit.

The utility model is realized by adopting the following technical scheme: an industrial steam supply thermodynamic system for deep peak regulation of a coal-fired steam turbine generator unit comprises a back press A (high-parameter back press), a bypass machine (the back press with a bypass level group, the variable working condition range is wide) and a back pressure machine B (low-parameter back press), wherein the back press A and the bypass machine are connected through a coupling, a steam inlet pipeline of the back pressure machine A is connected with a boiler superheater, a steam inlet regulating valve of the back pressure machine A is arranged on the steam inlet pipeline, a steam inlet pipeline of the bypass machine is connected with a boiler reheater, a bypass machine steam inlet regulating valve is arranged on the steam inlet pipeline, a steam inlet end of the bypass machine is connected with a steam inlet check valve of the back pressure machine A through the back press A steam outlet check valve, a steam outlet pipeline of the back pressure machine A is connected with a steam inlet pipeline of the bypass machine through the back press A steam outlet valve, a main machine reheat cold section is connected with a steam inlet regulating valve of the back pressure machine B through the back pressure machine B, and the back pressure machine A steam flows to the back pressure machine A from the back pressure machine through the back pressure check valve, and the back pressure machine A flows to the back pressure valve is.

The steam source of the back press A is a high-pressure steam source, and is generally taken from an intermediate header with proper temperature of a boiler superheater, when the unit load is too low, the back press A can also be taken from an outlet of a final-stage superheater, the steam source of the bypass machine is a medium-pressure steam source, and is generally taken from the intermediate header with proper temperature of the boiler reheater, a cold section steam and a hot section steam mixing mode can also be adopted, and the back press A and the bypass machine can work in parallel or in series. In the low-load working condition of the unit, the back pressure machine A adopts a high-pressure steam source, the exhaust steam of the back pressure machine A is used as a steam source of the bypass machine (the exhaust steam check valve of the back pressure machine A is in an open state), and the back pressure machine A and the bypass machine are connected in series to work; in the high-load working condition of the unit, the back pressure machine A and the bypass machine are in parallel connection (the back pressure machine A steam inlet check valve is in an open state), and steam inlet is taken from a medium-pressure steam source; the exhaust steam of the back pressure machine A and the bypass machine is used for industrial steam supply under the high load working condition of the unit, the exhaust steam of the bypass machine is used for industrial steam supply under the low load working condition of the unit, the surplus steam is used as a steam source of the back pressure machine B, and the exhaust steam of the back pressure machine B returns to a main machine regenerative system, namely is discharged to a low-pressure heater with the pressure close to (slightly lower than) the pressure; in the medium load working condition of the unit, the main machine reheat cold section directly provides industrial steam supply, the backpressure machine A and the bypass machine send certain steam flow from the medium pressure steam source to serve as cooling steam, exhaust steam returns to the main machine regenerative system through the ventilation valve, low output or idle running of the small machine is maintained, the backpressure machine B can determine the steam inlet flow according to the power requirement condition, and only the cooling steam flow can be maintained.

The beneficial effects of the utility model are as follows:

The utility model can reasonably and stepwise utilize the steam energy of the thermal power plant for industrial steam supply, and is not limited by the deep peak regulation of the unit.

The utility model can not influence the operation of the small machine under the condition that the demand of the industrial steam supply user is interrupted.

The utility model can make the small machine achieve higher internal efficiency under the condition of smaller industrial steam supply flow.

Drawings

Fig. 1 is a schematic diagram of an industrial steam supply thermodynamic system for deep peak shaving of a coal-fired steam turbine generator unit applied to a steam-electric double-drive induced draft fan of a coal-fired power plant.

In the figure: the device comprises a 1-back press A, a 2-bypass machine, a 3-back press B, a 4-back press A steam inlet regulating valve, a 5-bypass machine steam inlet regulating valve, a 6-back press B steam inlet regulating valve, a 7-bypass regulating valve, an 8-back press A steam inlet check valve, a 9-back press A steam outlet check valve, a 10-back press A steam outlet valve, an 11-bypass machine steam outlet valve, a 12-reheat cold section steam source regulating valve, a 13-back press A ventilation valve, a 14-bypass machine ventilation valve, a 15-coupling, a 16-power balance motor, a 17-induced draft fan, an 18-speed change clutch, a 19-gear box and a 20-electromechanical integrated planetary speed regulating device.

Detailed Description

Example 1: an industrial steam supply thermodynamic system for deep peak shaving of a coal-fired steam turbine generator unit is used for realizing external stable industrial steam supply under the peak shaving operation working condition of the unit by taking a steam-electricity double-drive induced draft fan applied to a coal-fired power plant as an example. The system comprises a back press A, a bypass machine 2, a back press B, a back press A steam inlet regulating valve 4, a bypass machine steam inlet regulating valve 5, a bypass valve 7, a back press B steam inlet regulating valve 6, a back press A steam inlet check valve 8, a back press A steam exhaust check valve 9, a back press A steam exhaust valve 10, a bypass machine steam exhaust valve 11, a reheat cold section steam source regulating valve 12, a back press A ventilation valve 13, a bypass machine ventilation valve 14, a coupling 15, a power balance motor 16, a draught fan 17, a variable-speed clutch 18, a gear box 19 and an electromechanical integrated planetary speed regulating device 20 (hereinafter referred to as a planetary speed regulating device), wherein the connection mode is shown in figure 1: the back press A is connected with the bypass machine 2 through a coupling 15, a steam inlet pipeline of the back press A is connected with a boiler superheater, a steam inlet regulating valve 4 of the back press A is arranged on the steam inlet pipeline, a steam inlet pipeline of the bypass machine 2 is connected with the boiler reheater, a steam inlet regulating valve 5 of the bypass machine is arranged on the steam inlet pipeline, a steam inlet end of the bypass machine 2 is connected with a steam inlet end of the back press A through a steam inlet check valve 8 of the back press A, a steam outlet pipeline of the back press A is connected with a steam inlet pipeline of the bypass machine 2 through a steam outlet check valve 9 of the back press A, a steam outlet pipeline of the back press A is connected with an industrial steam supply pipeline through a steam outlet valve 11 of the bypass machine, a main machine reheating cold section is connected with a reheat cold section steam source regulating valve 12 through a steam inlet regulating valve 6 of the back press B, the steam flow direction of the back pressure machine A steam inlet check valve 8 flows from the bypass machine 2 to the back pressure machine A, the steam flow direction of the back pressure machine A steam outlet check valve 9 flows from the back pressure machine A to the bypass machine 2, the cooling steam outlet of the back pressure machine A is connected with a host No. 5 low-pressure heater through a pipeline, a back pressure machine A ventilation valve 13 is arranged on the pipeline, the cooling steam outlet of the bypass machine 2 is connected with the host No. 5 low-pressure heater through a pipeline, a bypass machine ventilation valve 14 is arranged on the pipeline, a bypass valve 7 is also arranged on the bypass machine 2, the steam outlet pipeline of the back pressure machine B is connected with the host No. 5 low-pressure heater, a reheat cold section is provided with a reheat cold section steam source regulating valve 12, the output shaft of the bypass machine 2 is connected with a draught fan 17 through a speed change clutch 18 and a power balance motor 16, one side output shaft of the back pressure machine B is connected with the draught fan 17 through a gear box 19, the output shaft of the other side is connected with a power balance motor 16 through a planetary speed regulating device.

High load working condition of the unit: the back press A and the bypass machine 2 work in parallel, a steam source is taken from a boiler reheater middle header, steam enters the bypass machine 2 through a bypass machine steam inlet regulating valve 5 to do work, steam enters the back press A through a back press A steam inlet check valve 8 to do work, exhaust steam of the back press A and the bypass machine 2 respectively passes through a back press A exhaust valve 10 and a bypass machine exhaust valve 11 to provide industrial steam supply to the outside through pipelines, wherein surplus steam enters the back press B through a back press B steam inlet regulating valve 6 to do work, and the exhaust steam is discharged to a host No. 5 low-pressure heater. The back press A steam inlet regulating valve 4, the back press A ventilation valve 13, the bypass machine ventilation valve 14 and the reheat cold section steam source regulating valve 12 are in a closed state, the back press A steam exhaust check valve 9 is in a check closed state, and the bypass valve 7 is in a regulating state according to the steam inlet pressure of the bypass machine 2.

Load working condition in the unit: the high-load working condition of the machine set is different from that of the machine set, the exhaust steam of the high-pressure cylinder of the main machine provides industrial steam supply through the reheating cold section steam source regulating valve 12, the exhaust steam valve 10 of the back pressure machine A and the exhaust steam valve 11 of the bypass machine are in a closed state, the ventilation valve 13 of the back pressure machine A and the ventilation valve 14 of the bypass machine are in an open state, the inlet steam regulating valve 5 of the bypass machine is in a smaller opening degree, a small amount of cooling steam is introduced into the bypass machine 2 and the back pressure machine A, the inlet steam regulating valve 5 of the bypass machine can be closed, a special cooling steam pipeline valve is additionally arranged, and if the cooling steam flow is too small and the pressure is too low, the inlet steam check valve 8 of the back pressure machine A can not be jacked, the back pressure machine A also needs to be provided with the special cooling steam pipeline valve. If the flow rate of the fed cooling steam is large, the back pressure machine A and the bypass machine 2 can also maintain the rated rotating speed, and the variable speed clutch 18 can also maintain the engagement state; if the flow of the fed cooling steam is small, the back pressure machine A and the bypass machine 2 can run at a reduced speed, keep a warmup state, and can increase the flow of the inlet steam at any time to improve the output; the admission can be completely cut off, the variable speed clutch 18 is disconnected, the backpressure machine A and the bypass machine 2 are stopped, the turning state is kept, the admission flow can be determined by the backpressure machine B according to the power requirement condition, and only the cooling steam flow can be maintained.

Low load condition of the unit: the back press A and the bypass machine 2 work in series, a steam source is taken from a middle header of the boiler superheater, when the load of a unit is too low, the steam can also be taken from an outlet of the final superheater, the steam enters the back press A to do work through a steam inlet regulating valve 4 of the back press A, the exhaust steam enters the bypass machine 2 to do work through a steam exhaust check valve 9 of the back press A, the exhaust steam of the bypass machine 2 externally provides industrial steam supply through a steam exhaust valve 11 of the bypass machine, the surplus steam enters the back press B to do work through a steam inlet regulating valve 6 of the back press B, and the exhaust steam is discharged to a low-pressure heater of a host No. 5. The bypass machine steam inlet regulating valve 5, the backpressure machine A steam outlet valve 10 and the reheat cold section steam source regulating valve 12 are in a closed state, the backpressure machine A steam inlet check valve 8 is in a check closed state, and the bypass valve 7 is in a regulating state according to the steam inlet pressure of the bypass machine 2.

In the peak regulation operation process of the unit, the steam inlet regulating valve 6 of the back press B is preferably adjusted to change the steam inlet and output of the back press B, so that the industrial steam supply pressure and flow are kept stable, and the steam inlet regulating valve 4 of the back press A or the steam inlet regulating valve 5 of the bypass machine is kept fully opened or at a larger opening degree so as to reduce throttling loss.

In the above-mentioned industrial steam supply thermodynamic system for deep peak regulation of the coal-fired turbo generator set, taking the steam-electricity double-drive induced draft fan applied to the coal-fired power plant as an example, the arrangement mode of the induced draft fan set shafting can adopt two modes in fig. 1, the back pressure machine a and the bypass machine 2 are uniformly regarded as a small machine equivalent to the back pressure machine B, the shafting of the back pressure machine a and the bypass machine 2 in fig. 1 is in a constant rotation speed mode, and the variable speed clutch 18 can cut off the small machine from the shafting, so that the induced draft fan is in a pure electric state. In fig. 1, the shafting of the back pressure machine B is in a variable speed mode, and the induced draft fan 17 can be operated in an energy-saving mode according to different loads of a unit by continuously adjusting speed by a planetary speed adjusting device or in a multi-speed mode, and the power balance motor 16 and the planetary speed adjusting device are arranged at the high speed end of the small machine, so that the volume and weight of the equipment can be reduced, and the manufacturing cost of the equipment can be reduced. Generally, two induced draft fans are mostly arranged in a coal-fired power plant boiler, and one of the constant speed mode or the variable speed mode can be uniformly adopted.

Because the industrial steam supply pressure is high, the specific volume of steam is small, if the small machines for driving two induced draft fans are completely the same small machines and are arranged in parallel, the small machine efficiency is influenced because the steam volume flow is small, and by adopting the scheme of the utility model, the back pressure machine A, the bypass machine and the back pressure machine B work in series, the small machine efficiency can be higher under the condition of the same industrial steam supply flow, and the exhaust steam of the back pressure machine B finally returns to the main machine heat recovery system, so that the scheme of the utility model can still form complete thermodynamic cycle even if a user stops industrial steam supply, and 3 small machines can work normally.

Because the primary reheating unit occupies most of the in-service units of the power grid, and the reheater of the primary reheating unit is the most ideal steam extraction position, a large amount of steam can be extracted, and the parameters are relatively close to those of user demands, but after the unit participates in deep peak shaving, the pressure of the reheater is always lower than the steam pressure required by industrial steam supply users, or the small machine cannot normally operate because of insufficient steam pressure difference.

Claims (1)

1. An industrial steam supply thermodynamic system for deep peak shaving of a coal-fired steam turbine generator unit is characterized in that: including back press A (1), bypass machine (2) and backpressure machine B (3), wherein back press A (1) and bypass machine (2) are connected through shaft coupling (15), back press A (1)'s admission line and boiler superheater are connected, be provided with back press A admission control valve (4) on this admission line, bypass machine (2) admission line and boiler reheater are connected, be provided with bypass machine admission control valve (5) on this admission line, back press A admission check valve (8) are passed through between admission end of bypass machine (2) and back press A's admission end, back press A (1)'s exhaust line is through back press A exhaust valve (10), bypass machine (2) exhaust line is through bypass machine exhaust valve (11), the main machine cold leg is through reheat cold section vapour source control valve (12), machine B (3) are all connected with industry steam supply line through back press B admission control valve (6), back press A (1) exhaust end and bypass machine (2) between through back press A's admission check valve (9).