Energy supply system for coupling double-cut-cylinder steam turbine with double back pressure turbines

Abstract

The utility model relates to an energy supply system for coupling a double-cut-cylinder steam turbine with double back pressure turbines, and the energy supply system enables two cut-cylinder energy supply units to be coupled, and flexibly selects a first cut-cylinder energy supply unit and / or a second cut-cylinder energy supply unit to cut off a low-pressure cylinder according to an external thermal load demand, so that most of medium-pressure cylinders exhaust steam to supply heat to the outside; the lower limit of the electrical load of the unit can be reduced, the peak regulation space of the power grid is improved, and the peak regulation flexibility of the unit can be improved. And after steam admission of the low-pressure cylinder is cut off, the cold end loss of the condenser is greatly reduced, and the circulation efficiency of the whole system is improved. Besides, the high-quality steam of the medium-pressure cylinder is used for driving the back pressure machine to do work, the generating capacity of the back pressure machine can provide part of auxiliary power, the comprehensive power utilization rate of a power plant is reduced, exhaust steam of the back pressure machine is used for driving the heat pump device or serving as a heat source of the heat supply network heater, and the heat pump device and the heat supply network heater are used for recycling waste heat in circulating water. The low-grade energy is fully utilized, and the external heat supply amount can be greatly increased.

Description

Technical Field

[0001] The present disclosure relates to the technical field of operation of thermal power units, and in particular to an energy supply system of a double-cut-cylinder steam turbine coupled with a double back pressure machine. Background Art

[0002] Nowadays, with the increase in the production capacity of new energy electricity, the requirements for the power load of power plants have decreased, and the power plant units need to have a larger peak-shaving space. In addition, in some areas of my country, the winter temperature is low and the heating cycle is long. The heating units are in a long-term operation mode of heat-to-electricity during the heating period, and their ability to participate in the peak-shaving of the power grid is weak. In response to the above problems, the existing technology uses heating transformation and operation optimization to improve the peak-shaving capacity of power plants. However, the improvement of the cogeneration system in the existing technology has problems such as poor peak-shaving flexibility, small peak-shaving space, and low heat utilization. Utility Model Content

[0003] The purpose of the present invention is to provide an energy supply system of a double-cut-cylinder steam turbine coupled with a double back compressor to solve the problems existing in the prior art, such as poor peak-shaving flexibility, small peak-shaving space and low heat utilization rate.

[0004] In order to achieve the above-mentioned object, the present disclosure provides an energy supply system of a double-cut-cylinder steam turbine coupled with a double back pressure machine, the energy supply system comprising a first cut-cylinder energy supply unit and a second cut-cylinder energy supply unit;

[0005] The first cylinder cutting energy supply unit comprises a first intermediate pressure cylinder exhaust main line and a first intermediate pressure cylinder exhaust auxiliary line, a first back pressure machine, a first heating network heater and a second heating network heater, which are arranged in parallel;

[0006] The first intermediate pressure cylinder and the first low pressure cylinder are connected through the first intermediate pressure cylinder exhaust main line and the first intermediate pressure cylinder exhaust auxiliary line; the first intermediate pressure cylinder exhaust main line includes a first exhaust branch line and a first heating branch line; the first exhaust branch line is provided with a first hydraulic shut-off valve, and the first intermediate pressure cylinder exhaust auxiliary line is provided with a first minimum flow regulating valve;

[0007] The outlet of the first heating branch line is respectively connected to the exhaust steam inlet of the first back pressure machine and the exhaust steam inlet of the second heating network heater; the exhaust steam outlet of the first back pressure machine is connected to the exhaust steam inlet of the first heating network heater; the drain outlet of the first heating network heater and the drain outlet of the second heating network heater are respectively used to communicate with the inlet of the boiler return water pipeline;

[0008] The second cylinder cutting energy supply unit comprises a second intermediate pressure cylinder exhaust main line and a second intermediate pressure cylinder exhaust auxiliary line, a second back pressure machine, a third heat network heater and a heat pump device arranged in parallel;

[0009] The second intermediate pressure cylinder and the second low pressure cylinder are connected through the second intermediate pressure cylinder exhaust main line and the second intermediate pressure cylinder exhaust auxiliary line; the second intermediate pressure cylinder exhaust main line includes a second exhaust branch line and a second heating branch line; the second exhaust branch line is provided with a second hydraulic shut-off valve, and the second intermediate pressure cylinder exhaust auxiliary line is provided with a second minimum flow regulating valve;

[0010] The outlet of the second heating branch line is respectively connected to the exhaust steam inlet of the second back pressure machine and the exhaust steam inlet of the third heating network heater; the exhaust steam outlet of the second back pressure machine is connected to the exhaust steam inlet of the heat pump device; the drain outlet of the third heating network heater and the drain outlet of the heat pump device are respectively used to communicate with the inlet of the boiler return water pipeline;

[0011] The hot network water inlet of the heat pump device is used to communicate with the hot network water source, and the hot network water outlet of the heat pump device is connected to the hot network water inlet of the third hot network heater; the hot network water outlet of the third hot network heater is connected to the hot network water inlets of the second hot network heater and the first hot network heater respectively; the hot network water outlets of the second hot network heater and the first hot network heater are respectively used to communicate with the inlet of the heat-using device.

[0012] Optionally, the first back pressure machine is a synchronous back pressure steam turbine, and the second back pressure machine is an asynchronous back pressure steam turbine; the power of the first back pressure machine is 5 to 30 MW, and the power of the second back pressure machine is 5 to 20 MW.

[0013] Optionally, the power of the first back compressor is 20 MW, and the power of the second back compressor is 7 MW.

[0014] Optionally, the heat pump device comprises a lithium bromide heat pump.

[0015] Optionally, the first cylinder cutting energy supply unit also includes a first condenser, and the second cylinder cutting energy supply unit also includes a second condenser; the first condenser and the second condenser respectively include a low-pressure cylinder exhaust inlet, a boiler return water outlet, a cooling water inlet and a warming cooling water outlet; the low-pressure cylinder exhaust inlet of the first condenser is connected to the low-pressure cylinder exhaust outlet of the first low-pressure cylinder; the boiler return water outlet of the first condenser is used to be connected to the inlet of the boiler return water pipeline; the low-pressure cylinder exhaust inlet of the second condenser is connected to the low-pressure cylinder exhaust outlet of the second low-pressure cylinder; the boiler return water outlet of the second condenser is used to be connected to the inlet of the boiler return water pipeline.

[0016] Optionally, the first cylinder cutting energy supply unit also includes a first cooling tower, and the second cylinder cutting energy supply unit also includes a second cooling tower; the cooling water outlet of the first cooling tower is connected to the cooling water inlet of the first condenser, and the warming cooling water outlet of the first condenser is connected to the warming cooling water inlet of the first cooling tower; the cooling water outlet of the second cooling tower is connected to the cooling water inlet of the second condenser, and the warming cooling water outlet of the second condenser is connected to the warming cooling water inlet of the heat pump device; the warming cooling water outlet of the heat pump device is connected to the warming cooling water inlet of the second cooling tower.

[0017] Optionally, the first cylinder cutting energy supply unit also includes a first deaerator, and the second cylinder cutting energy supply unit also includes a second deaerator; the first deaerator and the second deaerator respectively include a boiler return water inlet and a deoxygenated water outlet; the boiler return water inlet of the first deaerator is connected to the drain outlets of the first heat network heater and the second heat network heater respectively; the deoxygenated water outlet of the first deaerator is used to be connected to the inlet of the boiler return water pipeline; the boiler return water inlet of the second deaerator is connected to the drain outlets of the third heat network heater and the heat pump device respectively; the deoxygenated water outlet of the second deaerator is used to be connected to the inlet of the boiler return water pipeline.

[0018] Optionally, the boiler return water outlet of the first condenser is communicated with the boiler return water inlet of the first deaerator; and the boiler return water outlet of the second condenser is communicated with the boiler return water inlet of the second deaerator.

[0019] Optionally, the energy supply system includes a first hot network water jumper and a second hot network water jumper; the hot network water inlet pipeline of the heat pump device and the hot network water outlet pipeline of the heat pump device are connected through the first hot network water jumper; a first hot network water shut-off valve is provided on the first hot network water jumper to adjust the flow direction of the hot network water; the hot network water inlet pipeline of the third hot network heater and the hot network water outlet pipeline of the third hot network heater are connected through the second hot network water jumper; a second hot network water shut-off valve is provided on the second hot network water jumper to adjust the flow direction of the hot network water.

[0020] Optionally, a third hot water shut-off valve is provided on the hot water inlet pipeline of the heat pump device, and the third hot water shut-off valve is arranged downstream of the connection between the first hot water crossover line and the hot water inlet pipeline of the heat pump device, for adjusting the flow direction of the hot water network; a fourth hot water shut-off valve is provided on the hot water inlet pipeline of the third hot water network heater, and the fourth hot water shut-off valve is arranged downstream of the connection between the second hot water crossover line and the hot water inlet pipeline of the third hot water network heater, for adjusting the flow direction of the hot water network; a fifth hot water shut-off valve is provided on the hot water inlet pipeline of the second hot water network heater, for adjusting the flow direction of the hot water network; a sixth hot water shut-off valve is provided on the hot water inlet pipeline of the first hot water network heater, for adjusting the flow direction of the hot water network.

[0021] Through the above technical solution, two cylinder cutting energy supply units are coupled. According to the external heat load demand, the first cylinder cutting energy supply unit and / or the second cylinder cutting energy supply unit are flexibly selected to cut off the low-pressure cylinder, so that most of the medium-pressure cylinder exhaust steam can be used for external heat supply, which can not only reduce the lower limit of the unit's electrical load and increase the space for grid peak regulation, but also improve the flexibility of the unit's peak regulation. In addition, after cutting off the low-pressure cylinder inlet steam, the cold end loss of the condenser is greatly reduced, and the circulation efficiency of the entire system is improved. In addition, the high-quality steam of the medium-pressure cylinder is used to drive the back pressure machine to work. The power generation of the back pressure machine can provide part of the plant electricity and reduce the comprehensive power consumption rate of the power plant. The exhaust steam of the back pressure machine is used to drive the heat pump device or as a heat source for the heat network heater. The heat pump device and the heat network heater are used to recover the waste heat in the circulating water, so that the low-grade energy is fully utilized, which can greatly increase the external heat supply.

[0022] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:

[0024] Figure 1 It is a schematic diagram of an energy supply system of a double-cut-cylinder steam turbine coupled with a double back pressure machine disclosed in the present invention.

[0025] Description of Reference Numerals

[0026] 1A first cooling tower; 1B second cooling tower; 2A first condenser; 2B second condenser; 3A first deaerator; 3B second deaerator; 4A first hydraulic shut-off valve; 4B second hydraulic shut-off valve; 5A first minimum flow regulating valve; 5B second minimum flow regulating valve; 6 first heating network heater; 7 second heating network heater; 8 third heating network heater; 9 heat pump device; 10A first back pressure machine; 10B second back pressure machine; 15 first heating network water crossover line; 16 second heating network water crossover line; 17 first heating network shut-off valve; 18 second heating network shut-off valve; 19 third heating network shut-off valve; 20 fourth heating network shut-off valve; 21 fifth heating network shut-off valve; 22 sixth heating network shut-off valve;

[0027] IPA is the first intermediate pressure cylinder; IPB is the second intermediate pressure cylinder; LPA is the first low pressure cylinder; LPB is the second low pressure cylinder. DETAILED DESCRIPTION

[0028] The specific implementation of the present disclosure is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the present disclosure, and is not used to limit the present disclosure.

[0029] In the present disclosure, unless otherwise stated, the terms "first, second, third, fourth, fifth, sixth" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first, second, third, fourth, fifth, sixth" may explicitly or implicitly include one or more of the feature. In the description of the present disclosure, "plurality" means two or more, unless otherwise clearly and specifically defined.

[0030] like Figure 1 As shown, the present disclosure provides an energy supply system of a double-cut-cylinder steam turbine coupled with a double back pressure machine, the energy supply system comprising a first cut-cylinder energy supply unit and a second cut-cylinder energy supply unit;

[0031] The first cylinder cutting energy supply unit comprises a first intermediate pressure cylinder exhaust main line and a first intermediate pressure cylinder exhaust auxiliary line arranged in parallel, a first back pressure machine 10A, a first heating network heater 6 and a second heating network heater 7;

[0032] The first intermediate pressure cylinder IPA and the first low pressure cylinder LPA are connected through the first intermediate pressure cylinder exhaust main line and the first intermediate pressure cylinder exhaust sub-line; the first intermediate pressure cylinder exhaust main line includes a first exhaust branch line and a first heating branch line; the first exhaust branch line is provided with a first hydraulic shut-off valve 4A, and the first intermediate pressure cylinder exhaust sub-line is provided with a first minimum flow regulating valve 5A;

[0033] The outlet of the first heating branch line is connected to the exhaust steam inlet of the first back pressure machine 10A and the exhaust steam inlet of the second heating network heater 7 respectively; the exhaust steam outlet of the first back pressure machine 10A is connected to the exhaust steam inlet of the first heating network heater 6; the drain outlet of the first heating network heater 6 and the drain outlet of the second heating network heater 7 are respectively used to communicate with the inlet of the boiler return water pipeline;

[0034] The second cylinder cutting energy supply unit comprises a second intermediate pressure cylinder exhaust main line and a second intermediate pressure cylinder exhaust auxiliary line, a second back pressure machine 10B, a third heat network heater 8 and a heat pump device 9 arranged in parallel;

[0035] The second intermediate pressure cylinder IPB and the second low pressure cylinder LPB are connected through the second intermediate pressure cylinder exhaust main line and the second intermediate pressure cylinder exhaust sub-line; the second intermediate pressure cylinder exhaust main line includes a second exhaust branch line and a second heating branch line; the second exhaust branch line is provided with a second hydraulic shut-off valve 4B, and the second intermediate pressure cylinder exhaust sub-line is provided with a second minimum flow regulating valve 5B;

[0036] The outlet of the second heating branch line is respectively connected to the exhaust steam inlet of the second back pressure machine 10B and the exhaust steam inlet of the third heating network heater 8; the exhaust steam outlet of the second back pressure machine 10B is connected to the exhaust steam inlet of the heat pump device 9; the drain outlet of the third heating network heater 8 and the drain outlet of the heat pump device 9 are respectively used to communicate with the inlet of the boiler return water pipeline;

[0037] The hot network water inlet of the heat pump device 9 is used to communicate with the hot network water source, and the hot network water outlet of the heat pump device 9 is connected to the hot network water inlet of the third hot network heater 8; the hot network water outlet of the third hot network heater 8 is connected to the hot network water inlets of the second hot network heater 7 and the first hot network heater 6 respectively; the hot network water outlets of the second hot network heater 7 and the first hot network heater 6 are respectively used to communicate with the inlets of the heat-using devices.

[0038] Through the above technical solution, two cylinder cutting energy supply units are coupled. According to the external heat load demand, the first cylinder cutting energy supply unit and / or the second cylinder cutting energy supply unit are flexibly selected to cut off the low-pressure cylinder, so that most of the medium-pressure cylinder exhaust steam can be used for external heat supply, which can not only reduce the lower limit of the unit's electrical load and increase the space for grid peak regulation, but also improve the flexibility of the unit's peak regulation. In addition, after cutting off the low-pressure cylinder inlet steam, the cold end loss of the condenser is greatly reduced, and the circulation efficiency of the entire system is improved. In addition, the high-quality steam of the medium-pressure cylinder is used to drive the back pressure machine to work. The power generation of the back pressure machine can provide part of the plant electricity and reduce the comprehensive power consumption rate of the power plant. The exhaust steam of the back pressure machine is used to drive the heat pump device or as a heat source for the heat network heater. The heat pump device and the heat network heater are used to recover the waste heat in the circulating water, so that the low-grade energy is fully utilized, which can greatly increase the external heat supply.

[0039] In one embodiment, the first cylinder cutting energy supply unit has a first working state and a second working state; when the first cylinder cutting energy supply unit is in the first working state, the first minimum flow regulating valve 5A is closed and the first hydraulic shut-off valve 4A is opened, so that the first intermediate pressure cylinder IPA and the first low pressure cylinder LPA are connected through the first intermediate pressure cylinder exhaust main line, so that most of the intermediate pressure cylinder exhaust steam enters the low pressure cylinder to do work, and the remaining part of the intermediate pressure cylinder exhaust steam enters the functional unit; when the cylinder cutting energy supply unit is in the second working state, the first minimum flow regulating valve 5A is opened and the first hydraulic shut-off valve 4A is closed, so that the first intermediate pressure cylinder IPA and the first low pressure cylinder LPA are connected through the first intermediate pressure cylinder exhaust secondary line, so that most of the intermediate pressure cylinder exhaust steam enters the first heating branch line to supply heat to the outside.

[0040] In one embodiment, the second cylinder cutting energy supply unit has a third working state and a fourth working state; when the second cylinder cutting energy supply unit is in the third working state, the second minimum flow regulating valve 5B is closed and the second hydraulic shut-off valve 4B is opened, so that the second intermediate pressure cylinder IPB and the second low pressure cylinder LPB are connected through the second intermediate pressure cylinder exhaust main line, so that most of the intermediate pressure cylinder exhaust steam enters the low pressure cylinder to do work, and the remaining part of the intermediate pressure cylinder exhaust steam enters the functional unit; when the cylinder cutting energy supply unit is in the fourth working state, the second minimum flow regulating valve 5B is opened and the second hydraulic shut-off valve 4B is closed, so that the second intermediate pressure cylinder IPB and the second low pressure cylinder LPB are connected through the second intermediate pressure cylinder exhaust secondary line, so that most of the intermediate pressure cylinder exhaust steam enters the first heating branch line to supply heat to the outside.

[0041] In this embodiment, when the cylinder cutting energy supply unit is in the second working state, the external heat supply of the energy supply unit can be greatly improved to meet the growing heating demand in the northern region. At the same time, the peak-shaving lower limit of the unit can be reduced, providing more space for new energy companies to access the grid, increasing the peak-shaving range of the unit, and after cutting off the steam inlet of the low-pressure cylinder, the cold end loss of the condenser is greatly reduced, thereby improving the circulation efficiency of the entire system.

[0042] In a specific implementation, when the heat load demand of the power plant is extremely small, the first cylinder cutting energy supply unit can be put into the first working state, and the second cylinder cutting energy supply unit can be put into the third working state; at this time, only a small part of the intermediate pressure cylinder exhaust steam of the first cylinder cutting energy supply unit and the second cylinder cutting energy supply unit is used for external heat supply, and the remaining intermediate pressure cylinder exhaust steam is all used to enter the low pressure cylinder to do work.

[0043] In another specific implementation, when the heat load demand of the power plant is moderate, the first cylinder cutting energy supply unit can be put into the first working state, the second cylinder cutting energy supply unit can be put into the fourth working state, or the first cylinder cutting energy supply unit can be put into the second working state, and the second cylinder cutting energy supply unit can be put into the third working state; at this time, almost all of the intermediate pressure cylinder exhaust steam in the first cylinder cutting energy supply unit or the second cylinder cutting energy supply unit is used for external heat supply, and part of the intermediate pressure cylinder exhaust steam in the other cylinder cutting energy supply unit is used for external heat supply, and part of it enters the low pressure cylinder to perform work.

[0044] In another specific implementation, when the heat load demand of the power plant is extremely large, the first cylinder cutting energy supply unit can be put into the second working state, and the second cylinder cutting energy supply unit can be put into the fourth working state; at this time, almost all of the intermediate pressure cylinder exhaust steam in the first cylinder cutting energy supply unit and the second cylinder cutting energy supply unit is used to supply heat to the outside.

[0045] In one embodiment, the first back pressure machine 10A used by the first cylinder cutting energy supply unit and the second back pressure machine 10B used by the second cylinder cutting energy supply unit are both conventional choices in the field, and this application does not make special requirements. As long as the exhaust steam of the intermediate pressure cylinder can be used to generate electricity, for example, the first back pressure machine 10A is a synchronous back pressure steam turbine, and the second back pressure machine 10B is a synchronous back pressure steam turbine.

[0046] In one embodiment, the power of the first back compressor 10A is 5-30 MW, and the power of the second back compressor 10B is 5-15 MW.

[0047] In a preferred embodiment, the power of the first back compressor 10A is 5-25 MW, and the power of the second back compressor 10B is 5-10 MW.

[0048] In a further preferred embodiment, the power of the first back compressor 10A is 20 MW, and the power of the second back compressor 10B is 7 MW.

[0049] In one embodiment, the first back pressure machine 10A and the second back pressure machine 10B can be connected to the power grid, or directly connected to the power-consuming device, so that the electric energy generated by the back pressure machine can be fully utilized.

[0050] In the above embodiment, the high-quality steam of the medium-pressure cylinder is used to drive the first back compressor 10A and the second back compressor 10B to do work. The power generation of the back compressor can provide part of the plant electricity, reducing the comprehensive plant electricity consumption rate of the unit. The exhaust steam of the first back compressor 10A is used as the heat source of the second heating network heater 7, and the exhaust steam of the second back compressor 10B is used as the heat source of the heat pump device 9. The waste heat in the exhaust steam of the back compressor can be fully recovered, so that the low-grade energy can be fully utilized, which can greatly improve the external heat supply, increase the thermal-electric ratio of the heat supply, and reduce the thermoelectric coupling degree.

[0051] In one embodiment, the heat pump device 9 used in the present application is a conventional choice in the art, as long as it can recover the heat of the exhaust steam of the second back compressor 10B. For example, the heat pump device 9 is selected from a lithium bromide heat pump.

[0052] In the above-mentioned embodiment, the high-quality steam of the medium-pressure cylinder is used to drive the second back compressor 10B to do work. The power generation of the second back compressor 10B can provide part of the plant electricity, reducing the comprehensive plant electricity consumption rate of the unit. The exhaust steam of the second back compressor 10B is used to drive the absorption-type large-scale lithium bromide heat pump to do work. The heat pump technology is used to recover the waste heat in the circulating water, so that the low-grade energy is fully utilized, which can greatly improve the external heat supply, increase the thermal-electric ratio of the heat supply, and reduce the thermoelectric coupling degree.

[0053] In one embodiment, the first cylinder cutting energy supply unit also includes a first condenser 2A, and the second cylinder cutting energy supply unit also includes a second condenser 2B; the first condenser 2A and the second condenser 2B respectively include a low-pressure cylinder exhaust inlet, a boiler return water outlet, a cooling water inlet and a heating cooling water outlet; the low-pressure cylinder exhaust inlet of the first condenser 2A is connected to the low-pressure cylinder exhaust outlet of the first low-pressure cylinder LPA; the boiler return water outlet of the first condenser 2A is used to be connected to the inlet of the boiler return water pipeline; the low-pressure cylinder exhaust inlet of the second condenser 2B is connected to the low-pressure cylinder exhaust outlet of the second low-pressure cylinder LPB; the boiler return water outlet of the second condenser 2B is used to be connected to the inlet of the boiler return water pipeline.

[0054] In one embodiment, the first cylinder cutting energy supply unit also includes a first cooling tower 1A, and the second cylinder cutting energy supply unit also includes a second cooling tower 1B; the cooling water outlet of the first cooling tower 1A is connected to the cooling water inlet of the first condenser 2A, and the warming cooling water outlet of the first condenser 2A is connected to the warming cooling water inlet of the first cooling tower 1A; the cooling water outlet of the second cooling tower 1B is connected to the cooling water inlet of the second condenser 2B, and the warming cooling water outlet of the second condenser 2B is connected to the warming cooling water inlet of the heat pump device 9; the warming cooling water outlet of the heat pump device 9 is connected to the warming cooling water inlet of the second cooling tower 1B.

[0055] In the above embodiment, when the first cylinder cutting energy supply unit is in the second working state, a small amount of intermediate pressure cylinder exhaust steam is cooled by the low pressure cylinder rotor, enters the first condenser 2A, exchanges heat with the cooling water from the first cooling tower 1A, and then returns to the unit, and the cooling water obtained after heat exchange returns to the first cooling tower 1A for cooling; when the second cylinder cutting energy supply unit is in the fourth working state, a small amount of intermediate pressure cylinder exhaust steam is cooled by the low pressure cylinder rotor, enters the second condenser 2B, exchanges heat with the cooling water from the second cooling tower 1B, and then returns to the unit, and the cooling water obtained after heat exchange returns to the second cooling tower 1B for cooling.

[0056] In one embodiment, the first cylinder cutting energy supply unit further includes a first deaerator 3A, and the second cylinder cutting energy supply unit further includes a second deaerator 3B; the first deaerator 3A and the second deaerator 3B respectively include a boiler return water inlet and a deoxygenated water outlet; the boiler return water inlet of the first deaerator 3A is respectively connected to the drain outlets of the first heat network heater 6 and the second heat network heater 7; the deoxygenated water outlet of the first deaerator 3A is used to be connected to the inlet of the boiler return water pipeline; the boiler return water inlet of the second deaerator 3B is respectively connected to the drain outlets of the third heat network heater 8 and the heat pump device 9; the deoxygenated water outlet of the second deaerator 3B is used to be connected to the inlet of the boiler return water pipeline.

[0057] In this embodiment, if oxygen exists in the boiler return water, after the boiler return water returns to the boiler, under high temperature conditions, the heat exchange tubes of the unit are prone to rust and corrosion. Therefore, in order to extend the service life of the boiler, a deaerator is provided before the boiler return water returns to the boiler. Specifically, the drainage of the first heat network heater 6 and the second heat network heater 7 enters the first deaerator 3A for treatment and then returns to the unit, and the drainage of the third heat network heater 8 and the heat pump device 9 enters the second deaerator 3B for treatment and then returns to the unit.

[0058] In a preferred embodiment, the boiler return water outlet of the first condenser 2A is connected to the boiler return water inlet of the first deaerator 3A; the boiler return water outlet of the second condenser 2B is connected to the boiler return water inlet of the second deaerator 3B.

[0059] In one embodiment, a filtering device is provided inside the first condenser 2A and / or the second condenser 2B or on the boiler return water outlet pipeline to reduce the oxygen content, hardness and conductivity of the condensed water. The filtering device may be a membrane filtering device.

[0060] In one embodiment, the drain outlet pipelines of the first heating network heater 6 and the second heating network heater 7 and the boiler return water outlet pipeline of the first condenser 2A are merged into one to form a boiler return water main line, and the outlet of the boiler return water main line is connected to the inlet of the first deaerator 3A, so that the drain from the first heating network heater 6 and the second heating network heater 7 and the boiler return water of the first condenser 2A are mixed and then enter the first deaerator 3A for treatment and then return to the boiler.

[0061] In one embodiment, the drain outlet of the third heating network heater 8 and the heat pump device 9 and the boiler return water outlet pipeline of the second condenser 2B are merged into one to form a boiler return water main line, and the outlet of the boiler return water main line is connected to the inlet of the second deaerator 3B, so that the drain of the third heating network heater 8 and the heat pump device 9 and the boiler return water of the second condenser 2B are mixed and then enter the second deaerator 3B for treatment and then return to the boiler.

[0062] In one embodiment, a hot water heater may also be provided in the first cylinder cutting energy supply unit and / or the second cylinder cutting energy supply unit, and the hot water heater includes a drain inlet, a drain outlet, a boiler return water inlet and a boiler return water outlet; the drain inlet of the hot water heater is connected to the inlet of the formed boiler return water main line, and the drain outlet of the hot water heater is connected to the drain inlet of the condenser; the boiler return water outlet of the drain condenser is connected to the boiler return water inlet of the hot water heater, and the boiler return water outlet of the hot water heater is connected to the boiler return water inlet of the deaerator.

[0063] In this embodiment, since the drain of the first heat network heater 6, the second heat network heater 7, the third heat network heater 8 and the heat pump device 9 still has a high enthalpy value, the hot water heater is used to heat the condensate of the low-pressure cylinder exhaust steam, and the drain heat is transferred to the condensate, so that the condensate temperature is increased, and the step-by-step utilization of heat is achieved. In this embodiment, due to the problems of high oxygen content, hardness and conductivity of the drain caused by the leakage of the heat network heater, after the drain of the hot water heater is recovered to the condenser, the deoxygenation function of the condenser and the mixed bed filtration of the condensate system can be used to improve the condensate quality, thereby ensuring the water quality of the unit.

[0064] In one embodiment, the energy supply system includes a first hot network water crossover line 15 and a second hot network water crossover line 16; the hot network water inlet pipeline of the heat pump device 9 and the hot network water outlet pipeline of the heat pump device 9 are connected through the first hot network water crossover line 15; the first hot network water crossover line 15 is provided with a first hot network shut-off valve 17 for adjusting the flow direction of hot network water; the hot network water inlet pipeline of the third hot network heater 8 and the hot network water outlet pipeline of the third hot network heater 8 are connected through the second hot network water crossover line 16; the second hot network water crossover line 16 is provided with a second hot network shut-off valve 18 for adjusting the flow direction of hot network water.

[0065] In one embodiment, a third hot water shut-off valve 19 is provided on the hot water inlet pipeline of the heat pump device 9, and the third hot water shut-off valve 19 is arranged downstream of the connection between the first hot water crossover line 15 and the hot water inlet pipeline of the heat pump device 9, for adjusting the flow direction of the hot water; a fourth hot water shut-off valve 20 is provided on the hot water inlet pipeline of the third hot water network heater 8, and the fourth hot water shut-off valve 20 is arranged downstream of the connection between the second hot water crossover line 16 and the hot water inlet pipeline of the third hot water network heater 8, for adjusting the flow direction of the hot water; a fifth hot water shut-off valve 21 is provided on the hot water inlet pipeline of the second hot water network heater 7, for adjusting the flow direction of the hot water; a sixth hot water shut-off valve 22 is provided on the hot water inlet pipeline of the first hot water network heater 6, for adjusting the flow direction of the hot water network.

[0066] In a specific embodiment, when the heat pump device 9 is abnormal, the first hot water shut-off valve 17 can be opened and the third hot water shut-off valve 19 can be closed, so that the hot water directly enters the third hot water heater 8, the second hot water heater 7 and the first hot water heater 6 in sequence through the first hot water crossover line 15 for heat exchange. When the third hot water heater 8 is abnormal, the second hot water shut-off valve 18 can be opened and the fourth hot water shut-off valve 20 can be closed, so that the hot water passes through the heat pump device 9, the second hot water crossover line 16, the second hot water heater 7 and the first hot water heater 6 in sequence for heat exchange. When the second hot water heater 7 is abnormal, the fifth hot water shut-off valve 21 is closed, so that the hot water passes through the heat pump device 9, the third hot water heater 8 and the first hot water heater 6 in sequence for heat exchange. When the first hot water heater 6 is abnormal, the sixth hot water shut-off valve 22 is closed, so that the hot water passes through the heat pump device 9, the third hot water heater 8 and the second hot water heater 7 in sequence for heat exchange.

[0067] In one embodiment, if Figure 1 The operation mode of the energy supply system of the double-cut-cylinder steam turbine coupled with the double back compressor includes:

[0068] The first cylinder energy supply unit: close the first hydraulic shut-off valve 4A, and adjust the minimum flow regulating valve 5, so that a very small part of the medium-pressure cylinder exhaust steam (20t / h) enters the first low-pressure cylinder cooling rotor for cooling through the first medium-pressure cylinder exhaust steam branch line; most of the medium-pressure cylinder exhaust steam enters the first heating branch line, and the medium-pressure cylinder exhaust steam entering the first heating branch line is divided into two streams, one of which enters the first back pressure machine 10A to do work, and the first back pressure machine 10A exhaust steam obtained enters the first heating network heater 6 for heat exchange to obtain the first heating network heater drain; the other stream enters the second heating network heater 7 for heat exchange to obtain the second heating network heater drain; the first heating network heater drain and the second heating network heater drain are mixed and then returned to the boiler after being treated by the first deaerator 3A; the low-pressure cylinder exhaust steam enters the first condenser 2A and exchanges heat with the cooling water in the first cooling tower 1A, and then enters the first deaerator 3A for treatment;

[0069] The second cylinder cutting energy supply unit: close the second hydraulic shut-off valve 4B, adjust the minimum flow regulating valve 5, so that a very small part of the medium-pressure cylinder exhaust steam enters the second low-pressure cylinder cooling rotor for cooling through the second medium-pressure cylinder exhaust steam branch line; make most of the medium-pressure cylinder exhaust steam enter the second heating branch line, and divide the medium-pressure cylinder exhaust steam entering the second heating branch line into two streams, one stream enters the second back pressure machine 10B to do work, and the obtained second back pressure machine 10B exhaust steam enters the third heat network heater 8 for heat exchange to obtain the third heat network heater drain; the other stream enters the heat pump device 9 for heat exchange to obtain the heat pump device drain; the third heat network heater drain and the heat pump device drain are mixed and then returned to the boiler after being treated in the second deaerator 3B; the low-pressure cylinder exhaust steam enters the second condenser 2B and exchanges heat with the cooling water in the second cooling tower 1B, and then enters the second deaerator 3B for treatment;

[0070] The heating network water is heated by the heat pump device 9 and the third heating network heater 8 in sequence, and then enters the heat-using device after heat exchange by the second heating network heater 7 and / or the first heating network heater 6.

[0071] When the heat pump device 9 is abnormal, the first heat network shut-off valve 17 can be opened and the third heat network shut-off valve 19 can be closed, so that the hot network water directly enters the third heat network heater 8, the second heat network heater 7 and the first heat network heater 6 in sequence through the first heat network water crossover line 15 for heat exchange. When the third heat network heater 8 is abnormal, the second heat network shut-off valve 18 can be opened and the fourth heat network shut-off valve 20 can be closed, so that the hot network water can be sequentially heat exchanged through the heat pump device 9, the second heat network water crossover line 16, the second heat network heater 7 and the first heat network heater 6. When the second heat network heater 7 is abnormal, the fifth heat network shut-off valve 21 is closed, so that the hot network water can be sequentially heat exchanged through the heat pump device 9, the third heat network heater 8 and the first heat network heater 6. When the first heat network heater 6 is abnormal, the sixth heat network shut-off valve 22 is closed, so that the hot network water can be sequentially heat exchanged through the heat pump device 9, the third heat network heater 8 and the second heat network heater 7.

[0072] By adopting the above system, two cylinder cutting energy supply units are coupled. According to the external heat load demand, the first cylinder cutting energy supply unit and / or the second cylinder cutting energy supply unit are flexibly selected to cut off the low-pressure cylinder, so that most of the medium-pressure cylinder exhaust steam can supply heat to the outside, which can not only reduce the lower limit of the unit's electrical load, increase the space for grid peak regulation, but also improve the flexibility of the unit's peak regulation. In addition, after cutting off the low-pressure cylinder inlet steam, the cold end loss of the condenser is greatly reduced, and the circulation efficiency of the entire system is improved. In addition, the high-quality steam of the medium-pressure cylinder is used to drive the back pressure machine to work. The power generation of the back pressure machine can provide part of the plant electricity and reduce the comprehensive power consumption rate of the power plant. The exhaust steam of the back pressure machine is used to drive the heat pump device and as a heat source for the heat network heater. The heat pump device and the heat network heater are used to recover the waste heat in the circulating water, so that the low-grade energy is fully utilized, which can greatly increase the external heat supply.

[0073] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings; however, the present disclosure is not limited to the specific details in the above embodiments. Within the technical concept of the present disclosure, a variety of simple modifications can be made to the technical solution of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0074] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0075] In addition, various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. A power supply system of a double-cut-cylinder steam turbine coupled with a double back compressor, characterized in that: The energy supply system comprises a first cutting cylinder energy supply unit and a second cutting cylinder energy supply unit; The first cylinder cutting energy supply unit comprises a first intermediate pressure cylinder exhaust main line and a first intermediate pressure cylinder exhaust auxiliary line arranged in parallel, a first back pressure machine (10A), a first heating network heater (6) and a second heating network heater (7); The first intermediate pressure cylinder (IPA) and the first low pressure cylinder (LPA) are connected through the first intermediate pressure cylinder exhaust main line and the first intermediate pressure cylinder exhaust auxiliary line; the first intermediate pressure cylinder exhaust main line includes a first exhaust branch line and a first heating branch line; the first exhaust branch line is provided with a first hydraulic shut-off valve (4A), and the first intermediate pressure cylinder exhaust auxiliary line is provided with a first minimum flow regulating valve (5A); The outlet of the first heating branch line is respectively connected to the exhaust steam inlet of the first back pressure machine (10A) and the exhaust steam inlet of the second heating network heater (7); the exhaust steam outlet of the first back pressure machine (10A) is connected to the exhaust steam inlet of the first heating network heater (6); the drain outlet of the first heating network heater (6) and the drain outlet of the second heating network heater (7) are respectively used to communicate with the inlet of the boiler return water pipeline; The second cylinder cutting energy supply unit comprises a second intermediate pressure cylinder exhaust main line and a second intermediate pressure cylinder exhaust auxiliary line arranged in parallel, a second back pressure machine (10B), a third heat network heater (8) and a heat pump device (9); The second intermediate pressure cylinder (IPB) and the second low pressure cylinder (LPB) are connected through the second intermediate pressure cylinder exhaust main line and the second intermediate pressure cylinder exhaust auxiliary line; the second intermediate pressure cylinder exhaust main line includes a second exhaust branch line and a second heating branch line; the second exhaust branch line is provided with a second hydraulic shut-off valve (4B), and the second intermediate pressure cylinder exhaust auxiliary line is provided with a second minimum flow regulating valve (5B); The outlet of the second heating branch line is respectively connected to the exhaust steam inlet of the second back pressure machine (10B) and the exhaust steam inlet of the third heating network heater (8); the exhaust steam outlet of the second back pressure machine (10B) is connected to the exhaust steam inlet of the heat pump device (9); the drain outlet of the third heating network heater (8) and the drain outlet of the heat pump device (9) are respectively used to communicate with the inlet of the boiler return water pipeline; The hot water network inlet of the heat pump device (9) is used to communicate with the hot water network source, and the hot water network outlet of the heat pump device (9) is connected to the hot water network inlet of the third hot water network heater (8); the hot water network outlet of the third hot water network heater (8) is respectively connected to the hot water network inlets of the second hot water network heater (7) and the first hot water network heater (6); the hot water network outlets of the second hot water network heater (7) and the first hot water network heater (6) are respectively used to communicate with the inlet of the heat-using device.

2. The energy supply system according to claim 1, characterized in that: The first back pressure machine (10A) is a synchronous back pressure steam turbine, and the second back pressure machine (10B) is an asynchronous back pressure steam turbine; The power of the first back pressure machine (10A) is 5-30 MW, and the power of the second back pressure machine (10B) is 5-15 MW.

3. The energy supply system according to claim 2, characterized in that: The power of the first back pressure machine (10A) is 20 MW, and the power of the second back pressure machine (10B) is 7 MW.

4. The energy supply system according to claim 1, characterized in that: The heat pump device (9) comprises a lithium bromide heat pump.

5. The energy supply system according to claim 1, characterized in that: The first cylinder cutting energy supply unit further comprises a first condenser (2A), and the second cylinder cutting energy supply unit further comprises a second condenser (2B); The first condenser (2A) and the second condenser (2B) respectively include a low-pressure cylinder exhaust steam inlet, a boiler return water outlet, a cooling water inlet and a heating cooling water outlet; The low-pressure cylinder exhaust inlet of the first condenser (2A) is connected to the low-pressure cylinder exhaust outlet of the first low-pressure cylinder (LPA); the boiler return water outlet of the first condenser (2A) is used to communicate with the inlet of the boiler return water pipeline; The low-pressure cylinder exhaust inlet of the second condenser (2B) is connected to the low-pressure cylinder exhaust outlet of the second low-pressure cylinder (LPB); the boiler return water outlet of the second condenser (2B) is used to communicate with the inlet of the boiler return water pipeline.

6. The energy supply system according to claim 5, characterized in that: The first cylinder cutting energy supply unit further comprises a first cooling tower (1A), and the second cylinder cutting energy supply unit further comprises a second cooling tower (1B); The cooling water outlet of the first cooling tower (1A) is in communication with the cooling water inlet of the first condenser (2A), and the warming cooling water outlet of the first condenser (2A) is in communication with the warming cooling water inlet of the first cooling tower (1A); The cooling water outlet of the second cooling tower (1B) is connected to the cooling water inlet of the second condenser (2B), and the warming cooling water outlet of the second condenser (2B) is connected to the warming cooling water inlet of the heat pump device (9); the warming cooling water outlet of the heat pump device (9) is connected to the warming cooling water inlet of the second cooling tower (1B).

7. The energy supply system according to claim 6, characterized in that: The first cylinder cutting energy supply unit further comprises a first deaerator (3A), and the second cylinder cutting energy supply unit further comprises a second deaerator (3B); The first deaerator (3A) and the second deaerator (3B) respectively include a boiler return water inlet and a deoxygenated water outlet; The boiler return water inlet of the first deaerator (3A) is connected to the drain outlets of the first heating network heater (6) and the second heating network heater (7) respectively; the deoxygenated water outlet of the first deaerator (3A) is used to communicate with the inlet of the boiler return water pipeline; The boiler return water inlet of the second deaerator (3B) is connected to the drain outlets of the third heating network heater (8) and the heat pump device (9) respectively; the deoxygenated water outlet of the second deaerator (3B) is used to be connected to the inlet of the boiler return water pipeline.

8. The energy supply system according to claim 7, characterized in that: The boiler return water outlet of the first condenser (2A) is in communication with the boiler return water inlet of the first deaerator (3A); The boiler return water outlet of the second condenser (2B) is in communication with the boiler return water inlet of the second deaerator (3B).

9. The energy supply system according to claim 1, characterized in that: The energy supply system comprises a first heating network water crossover line (15) and a second heating network water crossover line (16); The hot water inlet pipeline of the heat pump device (9) and the hot water outlet pipeline of the heat pump device (9) are connected via the first hot water jumper (15); the first hot water shut-off valve (17) is provided on the first hot water jumper (15) for adjusting the flow direction of the hot water; The hot water inlet pipeline of the third hot water network heater (8) and the hot water outlet pipeline of the third hot water network heater (8) are connected via a second hot water network jumper (16); a second hot water network shut-off valve (18) is provided on the second hot water network jumper (16) for adjusting the flow direction of the hot water network.

10. The energy supply system according to claim 9, characterized in that: A third hot water shut-off valve (19) is provided on the hot water inlet pipeline of the heat pump device (9), and the third hot water shut-off valve (19) is arranged downstream of the connection between the first hot water jumper (15) and the hot water inlet pipeline of the heat pump device (9), and is used to adjust the flow direction of the hot water. A fourth hot water shut-off valve (20) is provided on the hot water inlet pipeline of the third hot water network heater (8), and the fourth hot water shut-off valve (20) is arranged downstream of the connection point between the second hot water network crossover line (16) and the hot water inlet pipeline of the third hot water network heater (8), and is used to adjust the flow direction of the hot water network; A fifth hot water shut-off valve (21) is provided on the hot water inlet pipeline of the second hot water heater (7) for adjusting the flow direction of the hot water; A sixth hot water shut-off valve (22) is provided on the hot water inlet pipeline of the first hot water heater (6) for adjusting the flow direction of the hot water.

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