Energy supply system for coupling low-pressure bypass mode and cylinder switching mode of steam turbine

Abstract

The utility model relates to an energy supply system for coupling a low-pressure bypass mode and a cylinder switching mode of a steam turbine, and the energy supply system is provided with a cylinder switching energy supply unit and a low-pressure bypass energy supply unit, so that part of medium-pressure cylinder exhaust steam or reheat steam in a power plant unit enters the energy supply unit; the external heat supply amount of the energy supply system can be increased, the peak regulation lower limit of the unit can be reduced, then the peak regulation space of the power plant unit can be enlarged, and the purpose of fine peak regulation can be achieved. Meanwhile, the high-quality steam of the medium-pressure cylinder is used for driving the back pressure turbine to do work, the power generation amount of the back pressure turbine can provide part of auxiliary power, and the comprehensive power utilization rate of a power plant is reduced. Besides, exhaust steam of the back pressure machine, part of exhaust steam of the medium-pressure cylinder and part of reheated steam are used for driving the heat pump device and the heat supply network water heater, the heat pump and the heat supply network heater are used for recycling waste heat in circulating water or circulating gas, 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 steam turbine low-pressure bypass mode coupled with a cylinder cutting mode. Background Art

[0002] Due to the low winter temperature and long heating cycle in some areas of my country, heating units are in a long-term operation mode of heat-to-electricity during the heating period, and their ability to participate in grid peak regulation is relatively weak. Under the premise of meeting the stable operation of the power system, in order to meet the requirements of energy conservation and emission reduction of the power system and large-scale grid-connected power generation of renewable energy, it is urgent to improve the flexible operation capacity of thermal power, especially coal-fired power. Although the existing technology can meet the heating demand during the heating season through the transformation of cogeneration technology, the existing technology has problems such as poor peak regulation flexibility, small peak regulation space and low heat utilization rate. Utility Model Content

[0003] The purpose of the present invention is to provide a power supply system of a steam turbine low-pressure bypass mode coupled with a cylinder cutting mode, so as 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 a power supply system of a steam turbine low-pressure bypass mode coupled with a cylinder cutting mode, the power supply system comprising a cylinder cutting power supply unit and a low-pressure bypass power supply unit;

[0005] The 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 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 low-pressure bypass energy supply unit includes a reheat steam main line, a second intermediate-pressure cylinder exhaust main line, a second back pressure machine, a third heat network heater and a heat pump device; the second intermediate-pressure cylinder is connected to the reheater inlet of the unit through the reheat steam main line, and the second intermediate-pressure cylinder and the second low-pressure cylinder are connected through the second intermediate-pressure cylinder exhaust main line; the reheat steam main line includes a low-pressure bypass branch line and a reheat steam branch 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 low-pressure bypass branch line is provided with a low bypass fast closing valve;

[0009] The outlet of the second heating branch line is communicated with the exhaust steam inlet of the second back pressure machine; the exhaust steam outlet of the second back pressure machine is communicated with the exhaust steam inlet of the heat pump device; the outlet of the low-pressure bypass branch line is communicated with the exhaust steam inlet of the third heat network heater; the drain outlet of the heat pump device and the drain outlet of the third heat network heater are respectively used to communicate with the inlet of the boiler return water pipeline;

[0010] 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.

[0011] 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.

[0012] Optionally, the heat pump device comprises a lithium bromide heat pump.

[0013] Optionally, the cylinder cutting energy supply unit further includes a first condenser; the first condenser includes a low-pressure cylinder exhaust steam inlet, a boiler return water outlet, a cooling water inlet and a warming cooling water outlet; the low-pressure cylinder exhaust steam inlet of the first condenser is connected to the low-pressure cylinder exhaust steam outlet of the first low-pressure cylinder; the boiler return water outlet of the first condenser is used to communicate with the inlet of the boiler return water pipeline;

[0014] The low-pressure bypass energy supply unit also includes a second condenser and a hot water heater; the hot water heater includes a drain inlet, a drain outlet, a boiler return water inlet and a boiler return water outlet; the second condenser includes a low-pressure cylinder exhaust inlet, a drain inlet, a boiler return water outlet, a cooling water inlet and a heating cooling water outlet;

[0015] The drain outlets of the third heating network heater and the heat pump device are respectively connected to the drain inlet of the hot water heater; the drain outlet of the hot water heater is connected to the drain inlet of the second condenser, and the low-pressure cylinder exhaust inlet of the second condenser is connected to the exhaust outlet of the second low-pressure cylinder; the boiler return water outlet of the second condenser is connected to the boiler return water inlet of the hot water heater; the boiler return water outlet of the hot water heater is used to communicate with the inlet of the boiler return water pipeline.

[0016] Optionally, the cylinder cutting energy supply unit also includes a first deaerator, and the low-pressure bypass 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 drain outlet of the first heat network heater, the drain outlet of the second heat network heater and the boiler return water outlet of the first condenser are respectively connected to the boiler return water inlet of the first deaerator; 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 boiler return water outlet of the hot water heater; the deoxygenated water outlet of the second deaerator is used to be connected to the inlet of the boiler return water pipeline.

[0017] Optionally, the cylinder cutting energy supply unit also includes a first cooling tower, and the low-pressure bypass 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.

[0018] Optionally, a cooling water inlet is provided on the low-pressure bypass branch line; the cooling water inlet of the low-pressure bypass branch line is used to communicate with a cooling water source.

[0019] Optionally, a drain inlet is provided on the drain outlet pipeline of the heat pump device, and the drain inlet is connected to the drain outlet of the third heating network heater.

[0020] Optionally, the energy supply system comprises a first heating network water crossover line and a second heating network water crossover line; the heating network water inlet pipeline of the heat pump device and the heating network water outlet pipeline of the heat pump device are connected through the first heating network water crossover line;

[0021] A first hot water shut-off valve is provided on the first hot water network crossover line to adjust the flow direction of the hot water network;

[0022] The hot water inlet pipeline of the third hot water network heater and the hot water outlet pipeline of the third hot water network heater are connected through the second hot water network jumper;

[0023] A second hot water network shut-off valve is provided on the second hot water network crossover line for adjusting the flow direction of the hot water network.

[0024] 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.

[0025] Through the above technical scheme, by setting the cylinder cutting energy supply unit, most of the exhaust steam of the medium-pressure cylinder in the power plant unit enters the energy supply unit, which can increase the external heat supply of the energy supply system and reduce the lower limit of the peak load regulation of the unit; and, by setting the low-pressure bypass energy supply unit, the amount of reheated steam of the power plant unit entering the medium-pressure cylinder to do work and the energy supply unit can be flexibly adjusted, which can not only increase the peak load regulation space of the power plant unit, but also achieve the purpose of fine peak load regulation. At the same time, the high-quality steam of the medium-pressure cylinder is used to drive the back pressure machine to do work, and the power generation of the back pressure machine can provide part of the plant electricity, reducing the comprehensive power consumption rate of the power plant. In addition, the exhaust steam of the back pressure machine, part of the exhaust steam of the medium-pressure cylinder and part of the reheated steam are used to drive the heat pump device and the heat network water heater, and the heat pump and the heat network heater are used to recover the waste heat in the circulating water or circulating gas, so that the low-grade energy is fully utilized, which can greatly increase the external heat supply.

[0026] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] 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:

[0028] Figure 1 It is a schematic diagram of an energy supply system of a steam turbine low-pressure bypass mode coupled with a cylinder cutting mode disclosed in the present invention.

[0029] Description of Reference Numerals

[0030] 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; 5 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; 11 hot water heater; 12 low bypass fast shut-off valve; 13 low bypass steam regulating valve; 14 low bypass steam shut-off valve; 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; 101 cooling water source;

[0031] 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

[0032] 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.

[0033] 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.

[0034] like Figure 1 As shown, the present disclosure provides a power supply system of a steam turbine low-pressure bypass mode coupled with a cylinder cutting mode, the power supply system comprising a cylinder cutting power supply unit and a low-pressure bypass power supply unit;

[0035] The 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;

[0036] 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 minimum flow regulating valve 5;

[0037] 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;

[0038] The low-pressure bypass energy supply unit includes a reheat steam main line, a second intermediate-pressure cylinder exhaust main line, a second back pressure machine 10B, a third heat network heater 8 and a heat pump device 9; the second intermediate-pressure cylinder IPB is connected to the reheater inlet of the unit through the reheat steam main line, and the second intermediate-pressure cylinder IPB and the second low-pressure cylinder LPB are connected through the second intermediate-pressure cylinder exhaust main line; the reheat steam main line includes a low-pressure bypass branch line and a reheat steam branch 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 low-pressure bypass branch line is provided with a low bypass fast closing valve 12;

[0039] The outlet of the second heating branch line is communicated with the exhaust steam inlet of the second back pressure machine 10B; the exhaust steam outlet of the second back pressure machine 10B is communicated with the exhaust steam inlet of the heat pump device 9; the outlet of the low-pressure bypass branch line is communicated with the exhaust steam inlet of the third heating network heater 8; the drain outlet of the heat pump device 9 and the drain outlet of the third heating network heater 8 are respectively used to communicate with the inlet of the boiler return water pipeline;

[0040] 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.

[0041] Through the above technical scheme, by setting the cylinder cutting energy supply unit, most of the exhaust steam of the medium-pressure cylinder in the power plant unit enters the energy supply unit, which can increase the external heat supply of the energy supply system and reduce the lower limit of the peak load regulation of the unit; and, by setting the low-pressure bypass energy supply unit, the amount of reheated steam of the power plant unit entering the medium-pressure cylinder to do work and the energy supply unit can be flexibly adjusted, which can not only increase the peak load regulation space of the power plant unit, but also achieve the purpose of fine peak load regulation. At the same time, the high-quality steam of the medium-pressure cylinder is used to drive the back pressure machine to do work, and the power generation of the back pressure machine can provide part of the plant electricity, reducing the comprehensive power consumption rate of the power plant. In addition, the exhaust steam of the back pressure machine, part of the exhaust steam of the medium-pressure cylinder and part of the reheated steam are used to drive the heat pump device and the heat network water heater, and the heat pump and the heat network heater are used to recover the waste heat in the circulating water or circulating gas, so that the low-grade energy is fully utilized, which can greatly increase the external heat supply.

[0042] In one embodiment, the cylinder cutting energy supply unit has a first working state and a second working state;

[0043] When the cylinder cutting energy supply unit is in the first working state, the minimum flow regulating valve 5 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 minimum flow regulating valve 5 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 sub-line, so that most of the intermediate pressure cylinder exhaust steam enters the first heating branch line to supply heat to the outside.

[0044] In this embodiment, when the power generation demand of the power plant unit is high and the heating demand is low, the cylinder cutting unit is put into the first working state; when the heating demand of the power plant unit is high, the cylinder cutting energy supply unit is put into the second working state. In the second working state, the external heating 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 enterprises 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.

[0045] In one embodiment, the first back pressure machine 10A used in the cylinder cutting energy supply unit is a conventional choice in the art, and this application does not make any special requirements, as long as it can utilize the exhaust steam of the intermediate pressure cylinder to generate electricity. For example, the first back pressure machine 10A is a synchronous back pressure steam turbine.

[0046] In one embodiment, the power of the first back pressure machine 10A is 5-30 MW.

[0047] In a preferred embodiment, the power of the first back pressure machine 10A is 10-25 MW.

[0048] In a further preferred embodiment, the power of the first back pressure machine 10A is 20 MW.

[0049] In the above embodiment, the high-quality steam of the medium-pressure cylinder is used to drive the first back compressor 10A to do work. The power generation of the first back compressor 10A 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 heat network heater 7, and the waste heat in the exhaust steam of the back compressor can be 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.

[0050] In one embodiment, the cylinder cutting energy supply unit also includes a first condenser 2A; the first condenser 2A includes 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 steam inlet of the first condenser 2A is connected to the low-pressure cylinder exhaust steam outlet of the first low-pressure cylinder LPA; the boiler return water outlet of the first condenser 2A is used to connect to the inlet of the boiler return water pipeline.

[0051] In one embodiment, the cylinder cutting energy supply unit further includes a first cooling tower 1A, the cooling water outlet of the first cooling tower 1A is connected to the cooling water inlet of the first condenser 2A, and the heating cooling water outlet of the first condenser 2A is connected to the heating cooling water inlet of the first cooling tower 1A.

[0052] In the above embodiment, when the 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 and enters the first condenser 2A to exchange heat with the cooling water from the first cooling tower 1A, and the obtained boiler return water enters the first deaerator 3A for treatment and then returns to the unit, and the obtained cooling water after heat exchange returns to the first cooling tower 1A for cooling.

[0053] In one embodiment, the cylinder cutting energy supply unit also includes a first deaerator 3A, which includes a boiler return water inlet and a deoxygenated water outlet; the drain outlet of the first heat network heater 6, the drain outlet of the second heat network heater 7 and the boiler return water outlet of the first condenser 2A are respectively connected to the boiler return water inlet of the first deaerator 3A; the deoxygenated water outlet of the first deaerator 3A is used to connect to the inlet of the boiler return water pipeline.

[0054] In this embodiment, the drainage water from the first heating network heater 6 and the second heating network heater 7 enters the first deaerator 3A for treatment and then returns to the unit. If there is oxygen 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, the first deaerator 3A can be set before the boiler return water returns to the boiler.

[0055] In one embodiment, the drain outlet pipelines of the first heating network heater 6 and the second heating network heater 7 can be merged into one drain pipeline, or the drain outlet pipeline of the first heating network heater 6, the drain outlet pipeline of the second heating network heater 7 and the boiler return water outlet pipeline of the first condenser 2A can be merged into one drain pipeline, and the outlet of the drain pipeline is connected to the boiler return water inlet of the first deaerator 3A.

[0056] In one embodiment, the second back pressure machine 10B used in the low pressure bypass energy supply unit is a conventional choice in the art, and this application does not make any special requirements, as long as it can generate electricity by utilizing the exhaust steam from the intermediate pressure cylinder. For example, the second back pressure machine 10B is an asynchronous back pressure steam turbine.

[0057] In one embodiment, the power of the second back pressure machine 10B is 5-15 MW.

[0058] In one embodiment, the power of the second back pressure machine 10B is 5-10 MW.

[0059] In a further preferred embodiment, the power of the second back pressure machine 10B is 7 MW.

[0060] 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.

[0061] 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.

[0062] In one embodiment, the low-pressure bypass energy supply unit also includes a second condenser 2B and a hot water heater 11; the hot water heater 11 includes a drain inlet, a drain outlet, a boiler return water inlet and a boiler return water outlet; the second condenser 2B includes a low-pressure cylinder exhaust inlet, a drain inlet, a boiler return water outlet, a cooling medium inlet and a cooling medium outlet; the drain outlets of the third heat network heater 8 and the heat pump device 9 are respectively connected to the drain inlet of the hot water heater 11; the drain outlet of the hot water heater 11 is connected to the drain inlet of the second condenser 2B, and 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 connected to the boiler return water inlet of the hot water heater 11; the boiler return water outlet of the hot water heater 11 is used to be connected to the inlet of the boiler return water pipeline.

[0063] In one embodiment, the low-pressure bypass energy supply unit also includes a second cooling tower 1B; 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.

[0064] 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.

[0065] In this embodiment, since the drain of the third heating network heater 8 and the heat pump device 9 still has a high enthalpy value, the hot water heater 11 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 heat is used in a step-by-step manner. Due to the problems of high oxygen content, hardness and conductivity of the drain caused by the leakage of the heating network heater, after the drain of the hot water heater 11 is recovered to the second condenser 2B, the deoxygenation function of the second condenser 2B 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.

[0066] In one embodiment, the low-pressure bypass energy supply unit also includes a second deaerator 3B; the second deaerator 3B includes a boiler return water inlet and a deoxygenated water outlet respectively; the boiler return water inlet of the second deaerator 3B is connected to the boiler return water outlet of the hot water heater 11; the deoxygenated water outlet of the second deaerator 3B is used to connect to the inlet of the boiler return water pipeline.

[0067] In one embodiment, a cooling water inlet is provided on the low-pressure bypass branch line; the cooling water inlet of the low-pressure bypass branch line is used to communicate with a cooling water source.

[0068] In one embodiment, a low bypass steam regulating valve 13 and a low bypass steam shut-off valve 14 are also provided on the low-pressure bypass branch line, and along the direction of the logistics in the low-pressure bypass branch line, a low bypass quick closing valve 12, a cooling water inlet, a low bypass steam regulating valve 13 and a low bypass steam shut-off valve 14 are sequentially arranged.

[0069] In this embodiment, the low bypass quick closing valve 12 is used to adjust the flow of reheated steam entering the low-pressure bypass branch line, so as to achieve the purpose of fine peak regulation; the low bypass steam regulating valve 13 and the low bypass steam shut-off valve 14 are used to adjust the state of the exhaust steam entering the third heating network heater 8; since the temperature of the reheated steam is relatively high, in order to meet the purpose of step-by-step heating of the heating network water, it is necessary to spray cooling water to adjust the temperature of the exhaust steam entering the third heating network heater 8.

[0070] In one embodiment, a drain inlet is provided on the drain outlet pipeline of the heat pump device 9 , and the drain inlet is connected to the drain outlet of the third heating network heater 8 .

[0071] In one embodiment, the energy supply system includes a first hot network water jumper 15 and a second hot network water jumper 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 jumper 15; the first hot network water jumper 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 jumper 16; the second hot network water jumper 16 is provided with a second hot network shut-off valve 18 for adjusting the flow direction of hot network water.

[0072] 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.

[0073] 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.

[0074] In one embodiment, if Figure 1 The operation mode of the energy supply system of the steam turbine low-pressure bypass mode coupled with the cylinder cutting mode includes:

[0075] Cylinder cutting energy supply unit: close the first hydraulic shut-off valve 4A, adjust the minimum flow regulating valve 5, so that a very small part of the medium-pressure cylinder exhaust steam (20t / h) enters the low-pressure cylinder cooling rotor for cooling through the first medium-pressure cylinder exhaust steam branch line; make most of the medium-pressure cylinder exhaust steam enter the first heating branch line, and divide the medium-pressure cylinder exhaust steam entering the first heating branch line into two streams, one stream 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;

[0076] Low-pressure bypass energy supply unit: open the low bypass fast closing valve 12, the low bypass steam regulating valve 13 and the low bypass steam shut-off valve 14, close the first hydraulic shut-off valve 4A, and allow part of the reheated steam to enter the third heat network heater 8 through the low-pressure bypass branch line for heating, and obtain the third heat network heater 8 drain; allow the medium-pressure cylinder exhaust steam to enter the second heating branch line, and enter the second back pressure machine 10B through the second heating branch line to do work, and allow the obtained back pressure machine exhaust steam to enter the heat pump device 9 for heat exchange, and obtain the heat pump device 9 drain; allow the heat pump device 9 drain and the third heat network heater 8 drain to mix and then enter the hot water heater 11 for heat exchange, and allow the hot water heater 11 drain and the low-pressure cylinder exhaust steam to enter the second condenser 2B for condensation to obtain boiler return water; allow the boiler return water to return to the hot water heater 11 for heat exchange and then be treated in the second deaerator 3B before returning to the boiler;

[0077] 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.

[0078] When the heat pump device 9 malfunctions, the first hot water network shut-off valve 17 can be opened and the third hot water network shut-off valve 19 can be closed, so that the hot water network can directly enter the third hot water network heater 8, the second hot water network heater 7 and the first hot water network heater 6 in sequence through the first hot water network cross-line 15 for heat exchange.

[0079] When the third hot network heater 8 has an abnormality, the second hot network shut-off valve 18 can be opened and the fourth hot network shut-off valve 20 can be closed to allow the hot network water to exchange heat through the heat pump device 9, the second hot network water cross-line 16, the second hot network heater 7 and the first hot network heater 6 in sequence.

[0080] When the second heating network heater 7 is abnormal, the fifth heating network shut-off valve 21 is closed to allow the heating network water to exchange heat through the heat pump device 9, the third heating network heater 8 and the first heating network heater 6 in sequence.

[0081] When the first heating network heater 6 is abnormal, the sixth heating network shut-off valve 22 is closed to allow the heating network water to exchange heat through the heat pump device 9, the third heating network heater 8 and the second heating network heater 7 in sequence.

[0082] From the above description, it can be seen that the method disclosed in the present invention can improve the external heat supply of the energy supply system and reduce the lower limit of the peak load regulation of the unit, thereby improving the peak load regulation space of the power plant unit. At the same time, the high-quality steam of the medium-pressure cylinder is used to drive the back pressure machine to do work, and the power generation of the back pressure machine can provide part of the factory electricity, reducing the comprehensive power consumption rate of the power plant. In addition, the exhaust steam of the back pressure machine, part of the exhaust steam of the medium-pressure cylinder and part of the reheated steam are used to drive the heat pump device and the heat network water heater, and the heat pump and the heat network heater are used to recover the waste heat in the circulating water or circulating gas, so that the low-grade energy can be fully utilized, which can greatly improve the external heat supply.

[0083] 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; a variety of simple modifications can be made to the technical solutions of the present disclosure within the technical concept of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0084] 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.

[0085] 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 steam turbine low-pressure bypass mode coupled with a cylinder cutting mode, characterized in that: The energy supply system includes a cylinder cutting energy supply unit and a low-pressure bypass energy supply unit; The 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 minimum flow regulating valve (5); 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 low-pressure bypass energy supply unit comprises a reheat steam main line, a second intermediate-pressure cylinder exhaust main line, a second back pressure machine (10B), a third heat network heater (8) and a heat pump device (9); the second intermediate-pressure cylinder (IPB) is connected to the reheater inlet of the unit through the reheat steam main line, and the second intermediate-pressure cylinder (IPB) and the second low-pressure cylinder (LPB) are connected through the second intermediate-pressure cylinder exhaust main line; the reheat steam main line comprises a low-pressure bypass branch line and a reheat steam branch line; the second intermediate-pressure cylinder exhaust main line comprises 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 low-pressure bypass branch line is provided with a low-bypass quick-closing valve (12); The outlet of the second heating branch line is communicated with the exhaust steam inlet of the second back pressure machine (10B); the exhaust steam outlet of the second back pressure machine (10B) is communicated with the exhaust steam inlet of the heat pump device (9); the outlet of the low-pressure bypass branch line is communicated with the exhaust steam inlet of the third heating network heater (8); the drain outlet of the heat pump device (9) and the drain outlet of the third heating network heater (8) 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 1, characterized in that: The heat pump device (9) comprises a lithium bromide heat pump.

4. The energy supply system according to claim 1, characterized in that: The cylinder cutting energy supply unit also includes a first condenser (2A); The first condenser (2A) comprises 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 bypass energy supply unit also includes a second condenser (2B) and a hot water heater (11); The hot water heater (11) comprises a drain inlet, a drain outlet, a boiler return water inlet and a boiler return water outlet; the second condenser (2B) comprises a low-pressure cylinder exhaust steam inlet, a drain inlet, a boiler return water outlet, a cooling water inlet and a heating cooling water outlet; The drain outlets of the third heating network heater (8) and the heat pump device (9) are respectively connected to the drain inlet of the hot water heater (11); the drain outlet of the hot water heater (11) is connected to the drain inlet of the second condenser (2B), and the low-pressure cylinder exhaust inlet of the second condenser (2B) is connected to the exhaust outlet of the second low-pressure cylinder (LPB); the boiler return water outlet of the second condenser (2B) is connected to the boiler return water inlet of the hot water heater (11); the boiler return water outlet of the hot water heater (11) is used to communicate with the inlet of the boiler return water pipeline.

5. The energy supply system according to claim 4, characterized in that: The cylinder cutting energy supply unit further includes a first deaerator (3A), and the low-pressure bypass 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 drain outlet of the first heating network heater (6), the drain outlet of the second heating network heater (7) and the boiler return water outlet of the first condenser (2A) are respectively connected to the boiler return water inlet of the first deaerator (3A); 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 boiler return water outlet of the hot water heater (11); the deoxygenated water outlet of the second deaerator (3B) is used to communicate with the inlet of the boiler return water pipeline.

6. The energy supply system according to claim 4, characterized in that: The cylinder cutting energy supply unit further comprises a first cooling tower (1A), and the low-pressure bypass 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 1, characterized in that: The low-pressure bypass branch line is provided with a cooling water inlet; the cooling water inlet of the low-pressure bypass branch line is used to communicate with a cooling water source.

8. The energy supply system according to claim 1, characterized in that: The drain outlet pipeline of the heat pump device (9) is provided with a drain inlet, which is communicated with the drain outlet of the third heating network heater (8).

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 heat network water inlet pipeline of the heat pump device (9) and the heat network water outlet pipeline of the heat pump device (9) are connected via the first heat network water jumper (15); A first hot water shut-off valve (17) is provided on the first hot water network crossover line (15) for adjusting the flow direction of hot water network; 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 the second hot water network jumper (16); A second hot water network shut-off valve (18) is provided on the second hot water network crossover line (16) for adjusting the flow direction of 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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