阅读说明：本技术 基于乏汽内置群喷引射的高低压切缸热电解耦方式及系统 (High-low pressure cutting cylinder thermoelectric decoupling mode and system based on exhaust steam built-in group spraying injection ) 是由 李先庭 吕俊复 刘青 王垚 刘树昌 �路武 张茂勇 石文星 王宝龙 陈炜 崔梦迪 于 2020-06-14 设计创作，主要内容包括：基于乏汽内置群喷引射的高低压切缸热电解耦方式及系统,属于热电联产与集中供热技术领域。热电联产系统设置高、低压切缸用引射解耦装置,其中外置式高压切缸引射器的高压驱动蒸汽进口与新蒸汽管相连,低压进口与高压缸排汽冷再管相连,中压排汽口与锅炉再热器进口相连,热再管设置抽汽口；内置式低压群喷引射管束设置于低压缸与凝汽器之间的乏汽连通管内,其高压驱动蒸汽进口与热再抽汽口或中排汽口相通,低压进口开口于乏汽连通管内,中压排汽设置在凝汽器的乏汽进口前区域,凝汽器的冷却水进、出口分别与热网回水进、出水管相通并实现热网回水加热。本发明可实现汽轮机近全负荷供热及发电调节能力、消除冷端损失、提高火电运行灵活性。(High-low pressure cutting cylinder thermoelectric decoupling mode and system based on exhaust steam built-in group jet injection, and belongs to the technical field of cogeneration and centralized heating. The heat and power cogeneration system is provided with an injection decoupling device for high-pressure and low-pressure cutting cylinders, wherein a high-pressure driving steam inlet of an external high-pressure cutting cylinder injector is connected with a new steam pipe, a low-pressure inlet is connected with a high-pressure cylinder steam exhaust cold re-pipe, a medium-pressure steam exhaust port is connected with an inlet of a boiler reheater, and a heat re-pipe is provided with a steam extraction port; the built-in low-pressure group jet injection pipe bundle is arranged in an exhaust steam communication pipe between the low-pressure cylinder and the condenser, a high-pressure driving steam inlet of the built-in low-pressure group jet injection pipe bundle is communicated with a hot re-extraction steam port or a middle exhaust steam port, a low-pressure inlet is opened in the exhaust steam communication pipe, middle-pressure exhaust steam is arranged in the front area of the exhaust steam inlet of the condenser, and a cooling water inlet and a cooling water outlet of the condenser are respectively communicated with a return water inlet pipe and a return water outlet pipe of a heat supply network to realize. The invention can realize the near-full-load heat supply and power generation regulation capacity of the steam turbine, eliminate the loss of the cold end and improve the operation flexibility of thermal power.)

1. High-low pressure cutting cylinder thermoelectric decoupling mode and system based on exhaust steam built-in group jet injection, the system comprises a boiler superheater, a reheater, a steam turbine high-pressure cylinder, a medium-pressure cylinder, a low-pressure cylinder, a generator, a condenser, a heat supply network heater, a decoupling injection device and a connecting pipeline, and is characterized in that: the decoupling injection device comprises an external high-pressure cut cylinder ejector (20) and a built-in low-pressure group injection pipe bundle (51), wherein a high-pressure driving steam inlet (21) of the high-pressure cut cylinder ejector (20) is connected with a main steam pipe (9) between an outlet of a superheater (3) of a boiler (1) and an inlet of a high-pressure cylinder (4), a low-pressure steam inlet (22) of the high-pressure cut cylinder ejector (20) is connected with a steam exhaust port of the high-pressure cylinder (4) through a cold re-pipe (12), a medium-pressure steam exhaust outlet (23) of the high-pressure cut cylinder ejector (20) is connected with an inlet of a reheater (2) of the boiler (1) through a steam distribution desuperheater (24) and a steam distribution check valve (25), a steam outlet of the reheater (2) is connected with a steam inlet of an intermediate-pressure cylinder (5) through a hot re-pipe (13), and is also communicated with a high-pressure steam decompressor (Y1) through a high-pressure desuperheater (27), the low-pressure group jet ejector pipe bundle (51) is arranged in a cavity of an exhaust steam communicating pipe (50) between a low-pressure cylinder (6) and a condenser (19), the low-pressure group jet ejector pipe bundle (51) is composed of a group of unit ejectors (55), a unit high-pressure driving steam inlet (53) of each unit ejector (55) is connected with a steam outlet of a high-pressure temperature-reducing pressure reducer (27), a steam outlet of a medium-pressure cylinder (5) and a steam inlet of a heat net heater (57), a unit low-pressure steam inlet (54) of each unit ejector (55) is communicated with an upper low-pressure area of the exhaust steam communicating pipe (50), and a unit medium-pressure steam outlet (56) of each unit ejector (55) is connected with the steam inlet of the condenser (19) through a lower jet flow boosting area of the exhaust steam communicating pipe (50).

2. The high-low pressure cylinder cutting thermoelectric decoupling mode and system based on exhaust steam built-in group jet injection as claimed in claim 1, characterized in that the low-pressure group jet injection tube bundle (51), the exhaust steam communicating tube (50) and the condenser (19) form an integrated jet heat pump heating device, wherein a cooling circulating water inlet of the condenser (19) is connected with a water inlet pipe of primary network backwater (H), a cooling circulating water outlet of the condenser (19) is connected with a heat network water inlet of the heat network heater (57), and a heat network water outlet of the heat network heater (57) is communicated with a heating heat user (Y3).

3. The thermoelectric decoupling mode and system of high-low pressure cylinder cutting based on exhaust steam built-in group injection as claimed in claim 1, characterized in that a non-return variable pressure surface (52) is arranged inside the cavity of the exhaust steam communicating pipe (50), the upper space of the non-return variable pressure surface (52) is an exhaust steam low pressure area communicated with the steam outlet of the low pressure cylinder (6), and the lower space of the non-return variable pressure surface (52) is an exhaust steam jet flow boosting area communicated with the steam inlet of the condenser (19).

4. The thermoelectric decoupling mode and system of high-low pressure cut cylinder based on exhaust steam built-in group injection as claimed in claim 1, characterized in that the cold re-pipe (12) is provided with a cold re-check valve (26), the inlet and outlet of which are respectively connected with the low-pressure steam inlet (22) and the medium-pressure steam outlet (23) of the high-pressure cut cylinder injector (20).

5. The thermoelectric decoupling mode and the thermoelectric decoupling system for the high-low pressure cylinder cutting based on the exhaust steam built-in group injection as claimed in claims 2, 3 and 4 have the following working control method:

i. the steam supply quantity of the hot recycling pipe (13), the steam inlet quantity of the high-pressure cylinder (4) and the power generation load rates of the high-pressure cylinder (4) and the intermediate-pressure cylinder (5) are adjusted by the high-pressure cutting cylinder ejector (20), when the steam inlet quantity of the high-pressure cylinder (4) and the power generation load rates of the high-pressure cylinder (4) and the intermediate-pressure cylinder (5) are reduced, the actuating mechanism of the high-pressure driving steam inlet (21) is increased in opening degree, steam of the cold recycling pipe (12) enters the low-pressure steam inlet (22), the steam flow of the cold recycling check valve (26) is zero, when the power generation load demands of the high-pressure cylinder (4) and the intermediate-pressure cylinder (5) are reduced to the low limit, the pressure of the low-pressure steam inlet (22) is controlled by the actuating mechanism of the high-pressure cutting cylinder ejector (20) to eject and absorb all exhausted steam of the high-pressure cylinder (4) and realize stepless cutting of the high-pressure cylinder and the intermediate-pressure cylinder, and when the power generation load demands of the high-pressure cylinder (4) and the intermediate-pressure cylinder ( The injection ratio is improved to meet the pressure balance of a steam outlet of the high-pressure cylinder (4), when the demand of the external steam supply of the heat recovery pipe (13) changes, the opening degree is adjusted by an actuating mechanism of the high-pressure driving steam inlet (21) to control the steam inlet amount of the high-pressure driving steam inlet (21), and the quantity of the high-pressure driving steam inlet is determined according to the following relation: the demand of the external steam supply of the heat retrace pipe (13) is = the steam inlet amount of the high-pressure driving steam inlet (21) plus the temperature-reducing water amount of the steam distribution desuperheater (24) and the high-pressure desuperheater (27);

and ii, adjusting the heating quantity of the return water of a heat supply network of the condenser (19) and the steam inlet quantity and the power generation load rate of the low-pressure cylinder (6) by using the low-pressure group jet ejector pipe bundle (51), when the steam inlet quantity and the power generation load rate of the low-pressure cylinder (6) are reduced, adjusting the opening degree of an actuating mechanism of a unit high-pressure driving steam inlet (53) to keep the pressure of a steam outlet of the low-pressure cylinder (6) in a normal range, when the power generation load demand of the low-pressure cylinder (6) is reduced to the low limit of maintaining the cooling condition of a last-stage blade, realizing stepless cylinder switching of the low-pressure cylinder, when the power generation load demand of the low-pressure cylinder (6) is increased, increasing the steam inlet quantity of the high-pressure steam inlet by using the actuating mechanism of the unit high-pressure driving steam inlet (53) and improving the jet ratio to meet the pressure balance of the steam outlet of the low-pressure cylinder (.

6. The thermoelectric decoupling mode and system of high-low pressure cut cylinder based on exhaust steam built-in group jet injection as claimed in claim 1, characterized in that the high-pressure cut cylinder injector (20) adopts a stepless regulation joint type structure.

7. The high-low pressure cylinder-cutting thermoelectric decoupling mode and system based on exhaust steam built-in group injection is characterized in that the low-pressure group injection ejector pipe bundle (51) is of a group spray pipe bundle type structure consisting of a group of unit ejectors (55) connected in parallel, and each unit ejector (55) is of a stepless regulation joint type structure.

Technical Field

The invention relates to a high-low pressure cutting cylinder thermoelectric decoupling mode and system based on exhaust steam built-in group jet injection, and belongs to the technical field of cogeneration and waste heat recovery heating.

Background

Because of the inherent characteristic of thermoelectric coupling, the traditional cogeneration system of a thermal power plant usually adopts a running mode of using heat to fix power or using electricity to fix heat, and in view of the fact that the current power supply is greatly higher than the power demand, the heat supply demand, particularly the central heating demand of northern areas and the industrial steam supply demand of industrial parks are obviously increased all the time in a long period, so that the national energy source bureau and the like take a plurality of policy measures to promote the thermoelectric decoupling, deep peak regulation and flexible transformation of thermal power generation. The main tasks and essentials of thermoelectric decoupling are: on the premise of meeting the requirement of heat supply and greatly increasing, the power generation load rate is greatly reduced.

The existing thermoelectric decoupling schemes and their main problems are summarized as follows: the heat storage scheme and the electric boiler scheme have large occupied area and large investment scale and cannot realize comprehensive deep decoupling; the low pressure cylinder zero-output transformation comprises an optical axis scheme and a scheme of directly reducing or closing the steam inlet quantity of the low pressure cylinder and additionally introducing a small quantity of cooling steam to cool the final stage and a steam outlet, and the influence on the increase of the heat supply quantity is small; the high and low side combined steam distribution scheme has the problems that when the power generation load rate is low, the steam inlet amount of a steam turbine is greatly reduced, so that the steam inlet pressure of a reheater is greatly reduced, the volume flow is greatly increased, the through-flow capacity and the heat exchange amount of the reheater are greatly reduced, the smoke temperature of the reheater is difficult to effectively reduce, and the reheater and a heating surface behind the reheater are overtemperature and damaged; the power generation load rate cannot be effectively reduced by punching a cylinder to extract steam, heating low-vacuum circulating water and the like; the main steam is directly used for punching steam extraction, or the reheater cold section pipeline (cold re) punching steam extraction at the steam exhaust outlet of the high-pressure cylinder, or the hot section pipeline (hot re) punching steam extraction at the outlet of the reheater can greatly reduce the power generation load rate, but when the steam extraction amount is large, a series of safety problems such as reheater overheating, turbine axial thrust overrun and the like are inevitably caused.

By adopting an injection type steam pressure matching technology and an injection type heat pump exhaust steam waste heat recovery technology, a complete thermoelectric decoupling scheme can be realized, wherein the scheme comprises the following steps: an injection steam distribution thermoelectric decoupling mode based on axial thrust balance and reheat balance (application number 2019110733266), an injection heat pump exhaust steam recovery heat supply mode based on complete thermoelectric decoupling and a system thereof (application number 2019110728319, a thermoelectric decoupling system based on multi-stage injection steam distribution and heat pump exhaust steam recovery (patent number 2019219003781), an injection steam distribution deep thermoelectric decoupling system based on axial thrust balance (patent number 2019219003796) and the like can realize thermoelectric decoupling of large amplitude and near full load, but in the thermoelectric decoupling link of a low pressure cylinder, the minimum cooling condition of the low pressure cylinder is ensured, the waste heat recovery of the exhaust steam of the low pressure cylinder is realized, and cold end loss is eliminated, an injection heat pump technology is adopted, but in view of the fact that the exhaust steam quantity of the low pressure cylinder is often large and the specific volume and volume flow are large, for a wet cooling unit, a large-caliber pipeline is required to lead the exhaust steam to a place provided with a low pressure injector and a heater, the installation and maintenance space of the steam turbine room is usually compact, and the pipeline arrangement space is difficult, so the system is more suitable for an air cooling unit rather than a wet cooling unit, and the whole set of injection heat pump system including the ejector and the heating heat exchanger occupies a relatively large area and has relatively large investment.

Disclosure of Invention

The invention aims to solve the inherent problems in the deep thermoelectric decoupling, and adopts an external high-pressure cut cylinder ejector and a built-in low-pressure group jet ejector tube bundle, wherein the low-pressure group jet ejector tube bundle, an exhaust steam communicating pipe and a condenser form an integrated jet heat pump heating device, the flow of high-pressure steam and low-pressure steam of the ejector are regulated in a stepless manner according to a ratio, the exhaust steam waste heat of a low-pressure cylinder of a steam turbine is completely recovered for heating, and the thermoelectric decoupling and waste heat heating are realized to the greatest extent.

The specific description of the invention is: high-low pressure cutting cylinder thermoelectric decoupling mode and system based on exhaust steam built-in group jet injection, the system comprises a boiler superheater, a reheater, a steam turbine high-pressure cylinder, a medium-pressure cylinder, a low-pressure cylinder, a generator, a condenser, a heat supply network heater, a decoupling injection device and a connecting pipeline, and is characterized in that: the decoupling injection device comprises an external high-pressure cylinder cutting injector 20 and a built-in low-pressure group injection pipe bundle 51, wherein a high-pressure driving steam inlet 21 of the high-pressure cylinder cutting injector 20 is connected with a main steam pipe 9 between an outlet of a superheater 3 of the boiler 1 and an inlet of a high-pressure cylinder 4, a low-pressure steam inlet 22 of the high-pressure cylinder cutting injector 20 is connected with a steam exhaust port of the high-pressure cylinder 4 through a cold re-pipe 12, a medium-pressure steam exhaust outlet 23 of the high-pressure cylinder cutting injector 20 is connected with an inlet of a reheater 2 of the boiler 1 through a steam distribution desuperheater 24 and a steam distribution check valve 25, a steam outlet of the reheater 2 is connected with a steam inlet of a medium-pressure cylinder 5 through a hot re-pipe 13 and is also communicated with a high-pressure steam user Y1 through a high-pressure desuperheating decompressor 27, the low-pressure group injection pipe bundle 51 is arranged in a cavity of an exhaust steam communicating pipe 50 between, the low-pressure group jet ejector pipe bundle 51 is composed of a group of unit ejectors 55, a unit high-pressure driving steam inlet 53 of each unit ejector 55 is connected with a steam outlet of the high-pressure temperature-reducing pressure reducer 27, a steam outlet of the intermediate pressure cylinder 5 and a steam inlet of the heat supply network heater 57, a unit low-pressure steam inlet 54 of the unit ejector 55 is communicated with the upper low-pressure area of the exhaust steam communicating pipe 50, and a unit intermediate-pressure steam outlet 56 of the unit ejector 55 is connected with the steam inlet of the condenser 19 through a lower jet flow boosting area of the exhaust steam communicating pipe 50.

The low-pressure group jet ejector pipe bundle 51, the exhaust steam communicating pipe 50 and the condenser 19 form an integrated jet heat pump heating device, wherein a cooling circulating water inlet of the condenser 19 is connected with a water inlet pipe of primary network return water H, a cooling circulating water outlet of the condenser 19 is connected with a heat network water inlet of a heat network heater 57, and a heat network water outlet of the heat network heater 57 is communicated with a heating heat user Y3.

A non-return variable pressure surface 52 is arranged in the cavity of the exhaust steam communicating pipe 50, the upper space of the non-return variable pressure surface 52 is an exhaust steam low-pressure area communicated with the steam outlet of the low-pressure cylinder 6, and the lower space of the non-return variable pressure surface 52 is an exhaust steam jet flow boosting area communicated with the steam inlet of the condenser 19.

The cold recirculation pipe 12 is provided with a cold recirculation check valve 26, the inlet and outlet of which are connected to the low pressure steam inlet 22 and the medium pressure steam outlet 23 of the high pressure cylinder cutting injector 20, respectively.

A high-low pressure cutting cylinder thermoelectric decoupling mode and system based on exhaust steam built-in group injection comprises the following working control methods:

i. the high-pressure cylinder cutting ejector 20 is used for adjusting the steam supply quantity outside the hot recycling pipe 13, the steam inlet quantity of the high-pressure cylinder 4 and the power generation load rates of the high-pressure cylinder 4 and the intermediate-pressure cylinder 5, when the steam inlet quantity of the high-pressure cylinder 4 and the power generation load rates of the high-pressure cylinder 4 and the intermediate-pressure cylinder 5 are reduced, the actuating mechanism of the high-pressure driving steam inlet 21 is used for increasing the opening degree, the steam of the cold recycling pipe 12 enters the low-pressure steam inlet 22, the steam flow of the cold recycling check valve 26 is zero at the moment, when the power generation load demands of the high-pressure cylinder 4 and the intermediate-pressure cylinder 5 are reduced to a low limit, the actuating mechanism of the high-pressure cylinder cutting ejector 20 is used for controlling the pressure of the low-pressure steam inlet 22 so as to inject and absorb all the exhausted steam of the high-pressure cylinder 4 and realize stepless cylinder cutting of the high-pressure cylinder and the intermediate-pressure cylinder, when the power generation load demands of the high-pressure cylinder 4 and the intermediate-pressure cylinder 5, when the demand of the external supply steam of the heat recovery pipe 13 changes, the opening degree is adjusted by an actuating mechanism of the high-pressure driving steam inlet 21 to control the steam inlet amount of the high-pressure driving steam inlet 21, and the quantity is determined according to the following relation: the demand of the external steam supply of the heat retrace pipe 13 = the steam inlet amount of the high-pressure driving steam inlet 21 + the temperature-reducing water amount of the steam distribution desuperheater 24 and the high-pressure desuperheater 27;

and ii, adjusting the heating quantity of the return water of the heat supply network of the condenser 19 and the steam inlet quantity and the power generation load rate of the low-pressure cylinder 6 by the low-pressure group jet ejector pipe bundle 51, when the steam inlet quantity and the power generation load rate of the low-pressure cylinder 6 are reduced, adjusting the opening degree of an actuating mechanism of a unit high-pressure driving steam inlet 53 to keep the pressure of a steam outlet of the low-pressure cylinder 6 in a normal range, realizing stepless cylinder switching of the low-pressure cylinder when the power generation load demand of the low-pressure cylinder 6 is reduced to a low limit for maintaining the cooling condition of a last-stage blade, increasing the steam inlet quantity when the power generation load demand of the low-pressure cylinder 6 is increased, and increasing the high-pressure steam inlet quantity and increasing the jet ratio by the actuating mechanism of the unit high-pressure driving steam inlet 53 to meet the pressure balance of the steam outlet of the low.

The high-pressure cutting cylinder ejector 20 adopts a stepless regulation joint type structure.

The low-pressure group jet ejector pipe bundle 51 adopts a group jet pipe bundle structure consisting of a group of unit ejectors 55 connected in parallel, and each unit ejector 55 adopts a stepless regulation joint type structure.

The invention has the technical effects and advantages that: the technical principle of injection type is adopted, the high-pressure cylinder cutting is realized by using an external high-pressure cylinder cutting injector, the steam inlet amount of the high-pressure cylinder and the steam inlet amount of the intermediate pressure cylinder can be adjusted in proportion to ensure the axial thrust balance of the steam turbine, and the flow capacity and the cooling heat exchange amount of a reheater are improved to ensure the heat exchange balance, so that the safe operation of the boiler is efficiently and stably realized; the built-in low-pressure group jet pipe bundle is utilized, and forms an integrated jet heat pump device with the low-pressure cylinder exhaust steam communicating pipe and the condenser, so that exhaust steam waste heat is completely used for heating, the loss of a cold end of a steam turbine is eliminated, and the thermal efficiency of a system can be the same as that of a boiler; the thermoelectric ratio can be greatly adjusted, and the thermoelectric decoupling is fundamentally realized; the flexible cylinder switching of the built-in low-pressure cylinder is realized, the power generation load can be reduced to the maximum extent under the condition of large-load heat supply, the cold end loss can be eliminated, the power generation capacity and the heat supply quantity are improved, the high-degree thermal power flexible operation is realized, and the comprehensive energy utilization efficiency and the economical efficiency of the system operation are improved; the automatic steam pipeline, cold steam extraction and hot steam extraction are not needed, so that the serious safety problem is avoided; the system is simple and reliable, the occupied space is small, and particularly, the integrated injection heat pump device formed by the built-in low-pressure group injection pipe bundle and the like adopted by the low-pressure cylinder cutting cylinder hardly increases any occupied space; the modification workload is small; the system cost is reduced by 40-70% compared with the conventional decoupling mode; no extra energy consumption and raw material consumption, small operation and maintenance requirements and low operation cost.

Drawings

FIG. 1 is a schematic diagram of the system of the present invention.

The parts in fig. 1 are numbered and named as follows.

The system comprises a boiler 1, a reheater 2, a superheater 3, a high-pressure cylinder 4, an intermediate-pressure cylinder 5, a low-pressure cylinder 6, a generator 7, an inlet butterfly valve 8, a main steam pipe 9, a high-side pipe 10, a high-side regulating valve 11, a cold-recycling pipe 12, a hot-recycling pipe 13, an intermediate-pressure cylinder inlet valve 14, a high-pressure cylinder inlet valve 15, a condenser 19, a high-pressure cylinder cutting ejector 20, a high-pressure driving steam inlet 21, a low-pressure steam inlet 22, an intermediate-pressure steam outlet 23, a steam distribution desuperheater 24, a steam distribution check valve 25, a cold-recycling check valve 26, a high-pressure desuperheating decompressor 27, an exhaust steam communicating pipe 50, a low-pressure group injection pipe bundle 51, a check variable pressure surface 52, a unit high-pressure driving steam inlet 53, a unit low-pressure steam inlet 54, a unit ejector 55, a unit intermediate-pressure steam outlet 56, a heating network heater 57, an injection steam-discharge jet interface 58, cooling water inlet C1, high pressure steam user Y1, low pressure steam user Y2, heating heat user Y3.

Detailed Description

FIG. 1 is a system schematic and embodiment of the present invention.

Specific examples of the present invention are as follows.

High-low pressure cutting cylinder thermoelectric decoupling mode and system based on exhaust steam built-in group jet injection, the system comprises a boiler superheater, a reheater, a steam turbine high-pressure cylinder, a medium-pressure cylinder, a low-pressure cylinder, a generator, a condenser, a heat supply network heater, a decoupling injection device and a connecting pipeline, and is characterized in that: the decoupling injection device comprises an external high-pressure cylinder cutting injector 20 and a built-in low-pressure group injection pipe bundle 51, wherein a high-pressure driving steam inlet 21 of the high-pressure cylinder cutting injector 20 is connected with a main steam pipe 9 between an outlet of a superheater 3 of the boiler 1 and an inlet of a high-pressure cylinder 4, a low-pressure steam inlet 22 of the high-pressure cylinder cutting injector 20 is connected with a steam exhaust port of the high-pressure cylinder 4 through a cold re-pipe 12, a medium-pressure steam exhaust outlet 23 of the high-pressure cylinder cutting injector 20 is connected with an inlet of a reheater 2 of the boiler 1 through a steam distribution desuperheater 24 and a steam distribution check valve 25, a steam outlet of the reheater 2 is connected with a steam inlet of a medium-pressure cylinder 5 through a hot re-pipe 13 and is also communicated with a high-pressure steam user Y1 through a high-pressure desuperheating decompressor 27, the low-pressure group injection pipe bundle 51 is arranged in a cavity of an exhaust steam communicating pipe 50 between, the low-pressure group jet ejector pipe bundle 51 is composed of a group of unit ejectors 55, a unit high-pressure driving steam inlet 53 of each unit ejector 55 is connected with a steam outlet of the high-pressure temperature-reducing pressure reducer 27, a steam outlet of the intermediate pressure cylinder 5 and a steam inlet of the heat supply network heater 57, a unit low-pressure steam inlet 54 of the unit ejector 55 is communicated with the upper low-pressure area of the exhaust steam communicating pipe 50, and a unit intermediate-pressure steam outlet 56 of the unit ejector 55 is connected with the steam inlet of the condenser 19 through a lower jet flow boosting area of the exhaust steam communicating pipe 50.

The low-pressure group jet ejector pipe bundle 51, the exhaust steam communicating pipe 50 and the condenser 19 form an integrated jet heat pump heating device, wherein a cooling circulating water inlet of the condenser 19 is connected with a water inlet pipe of primary network return water H, a cooling circulating water outlet of the condenser 19 is connected with a heat network water inlet of a heat network heater 57, and a heat network water outlet of the heat network heater 57 is communicated with a heating heat user Y3.

A non-return variable pressure surface 52 is arranged in the cavity of the exhaust steam communicating pipe 50, the upper space of the non-return variable pressure surface 52 is an exhaust steam low-pressure area communicated with the steam outlet of the low-pressure cylinder 6, and the lower space of the non-return variable pressure surface 52 is an exhaust steam jet flow boosting area communicated with the steam inlet of the condenser 19.

The cold recirculation pipe 12 is provided with a cold recirculation check valve 26, the inlet and outlet of which are connected to the low pressure steam inlet 22 and the medium pressure steam outlet 23 of the high pressure cylinder cutting injector 20, respectively.

A high-low pressure cutting cylinder thermoelectric decoupling mode and system based on exhaust steam built-in group injection comprises the following working control methods:

i. the high-pressure cylinder cutting ejector 20 is used for adjusting the steam supply quantity outside the hot recycling pipe 13, the steam inlet quantity of the high-pressure cylinder 4 and the power generation load rates of the high-pressure cylinder 4 and the intermediate-pressure cylinder 5, when the steam inlet quantity of the high-pressure cylinder 4 and the power generation load rates of the high-pressure cylinder 4 and the intermediate-pressure cylinder 5 are reduced, the actuating mechanism of the high-pressure driving steam inlet 21 is used for increasing the opening degree, the steam of the cold recycling pipe 12 enters the low-pressure steam inlet 22, the steam flow of the cold recycling check valve 26 is zero at the moment, when the power generation load demands of the high-pressure cylinder 4 and the intermediate-pressure cylinder 5 are reduced to a low limit, the actuating mechanism of the high-pressure cylinder cutting ejector 20 is used for controlling the pressure of the low-pressure steam inlet 22 so as to inject and absorb all the exhausted steam of the high-pressure cylinder 4 and realize stepless cylinder cutting of the high-pressure cylinder and the intermediate-pressure cylinder, when the power generation load demands of the high-pressure cylinder 4 and the intermediate-pressure cylinder 5, when the demand of the external supply steam of the heat recovery pipe 13 changes, the opening degree is adjusted by an actuating mechanism of the high-pressure driving steam inlet 21 to control the steam inlet amount of the high-pressure driving steam inlet 21, and the quantity is determined according to the following relation: the demand of the external steam supply of the heat retrace pipe 13 = the steam inlet amount of the high-pressure driving steam inlet 21 + the temperature-reducing water amount of the steam distribution desuperheater 24 and the high-pressure desuperheater 27;

and ii, adjusting the heating quantity of the return water of the heat supply network of the condenser 19 and the steam inlet quantity and the power generation load rate of the low-pressure cylinder 6 by the low-pressure group jet ejector pipe bundle 51, when the steam inlet quantity and the power generation load rate of the low-pressure cylinder 6 are reduced, adjusting the opening degree of an actuating mechanism of a unit high-pressure driving steam inlet 53 to keep the pressure of a steam outlet of the low-pressure cylinder 6 in a normal range, realizing stepless cylinder switching of the low-pressure cylinder when the power generation load demand of the low-pressure cylinder 6 is reduced to a low limit for maintaining the cooling condition of a last-stage blade, increasing the steam inlet quantity when the power generation load demand of the low-pressure cylinder 6 is increased, and increasing the high-pressure steam inlet quantity and increasing the jet ratio by the actuating mechanism of the unit high-pressure driving steam inlet 53 to meet the pressure balance of the steam outlet of the low.

The high-pressure cutting cylinder ejector 20 adopts a stepless regulation joint type structure.

The low-pressure group jet ejector pipe bundle 51 adopts a group jet pipe bundle structure consisting of a group of unit ejectors 55 connected in parallel, and each unit ejector 55 adopts a stepless regulation joint type structure.

It should be noted that, the present invention provides an innovative built-in ejector structure and an integrated ejector heat pump device based on the comprehensive recovery of the low-pressure cylinder exhaust steam, provides the technical principles, technical methods and system composition of thermoelectric deep decoupling and flexibility modification, provides the theoretical basis of precise adjustment, and provides specific implementation methods for achieving the above objects, and according to this general solution, there may be different specific implementation measures and specific implementation devices of different structures, and the specific implementation methods are only one or more of them, and any other similar simple deformation implementation methods, for example, different ejector structures are adopted; the low-pressure ejector is arranged externally and returns exhaust steam to the condenser for heating; adding or reducing a plurality of pipeline connection schemes; or may be modified as would occur to those of ordinary skill in the art, and such modifications are intended to be included within the scope of the present invention.