Multi-scene heat supply and thermoelectric decoupling system of electrode steam boiler and spherical tank and operation method

Abstract

The invention discloses a multi-scene heat supply and thermoelectric decoupling system of an electrode steam boiler and a spherical tank and an operation method, belongs to the field of energy supply and conversion, and relates to the crossing field of heat energy storage, combined heat and power generation and power system flexibility adjustment technologies. The system achieves coupling of the electrode steam boiler and the spherical tank and deep fusion of the electrode steam boiler and the combined heat and power generation unit through cooperation of a water supply module, a steam preparation, storage and supply module and a heat supply network water heating module, a unit base load main supply and system dynamic supplementing and adjusting mode is formed, steam is efficiently prepared, stored and supplied, and industrial steam and livelihood heating are flexibly supplied. The problems that in the prior art, the heat storage cost is high, industrial heat consumption and livelihood heat consumption cannot be considered, heat supply under extreme working conditions is insufficient, the thermoelectric decoupling and peak regulation capacity is weak, and new energy consumption is poor can be solved, the heat supply capacity and reliability are improved, the thermoelectric decoupling and unit peak regulation capacity and operation stability (including flue gas emission compliance) are enhanced, the energy efficiency is improved, and the energy utilization rate is increased. New energy consumption is assisted, policy requirements are met, and remarkable economic and social benefits are achieved.

Description

Technical Field

[0001] This technology relates to energy supply and conversion, specifically falling at the intersection of thermal energy storage, combined heat and power (CHP), and power system flexibility regulation. Specifically, it involves a multi-scenario heating and thermoelectric decoupling system and operation method using an electrode steam boiler and a spherical tank, primarily applied to CHP units. Its core principle is to achieve efficient steam preparation, storage, and flexible supply through the synergistic coupling of the electrode steam boiler and the spherical tank. This system can meet the steam demands of industrial production and residential heating, while also improving the unit's peak-shaving capacity and overall energy utilization efficiency through the thermoelectric decoupling mechanism. Background Technology

[0002] 1. Limitations of existing thermal energy storage technologies: Although traditional molten salt thermal energy storage technology has achieved thermal energy storage to a certain extent, it has the problem of high initial investment, and molten salt has the risk of crystallization during use, which not only increases operating costs, but may also affect the stable operation of the system.

[0003] 2. The scheme combining boiler deep peak shaving retrofit with turbine bypass heating retrofit has two prominent problems: First, under deep peak shaving conditions, the boiler is prone to failure to meet flue gas emission standards; second, when the turbine intermediate valve participates in regulation, not only is the control logic complex, but it also faces the problem of severe valve erosion, affecting the stable operation of the system.

[0004] 3. Existing technology has a limited steam supply method: The existing electrode steam boiler and spherical tank coupling technology has a relatively limited steam supply scenario, which cannot fully meet the diverse steam needs of different users under different working conditions, thus limiting the flexibility and efficiency of energy supply.

[0005] 4. Insufficient heating capacity under extreme conditions: With the development of heating load, the heating capacity of traditional cogeneration units is significantly insufficient under extreme conditions such as extremely cold weather, making it difficult to meet the surge in heating demand. At the same time, when a single unit is shut down due to failure or maintenance, the reliability of heating supply drops significantly, and the risk of heating interruption is likely to occur, which will have an adverse impact on the heating security of people's livelihood.

[0006] 5. Policy guidance and demand: With the introduction of relevant policies, higher requirements have been placed on the flexibility, peak-shaving capacity and energy utilization efficiency of coal-fired power units. Traditional heating and steam supply systems are unable to meet these new requirements.

[0007] 6. Pressure on renewable energy consumption: As the proportion of renewable energy generation continues to increase, its volatility poses a challenge to the stable operation of the power grid. Coal-fired power units need to have stronger deep peak-shaving capabilities to consume the surplus electricity generated by renewable energy generation. Traditional systems are clearly insufficient in this regard. Summary of the Invention

[0008] The objectives of this invention are: 1) To address the shortcomings of existing thermal storage and steam upgrading technologies (such as molten salt thermal storage) such as high initial investment and the risk of crystallization, this invention uses water / steam as the thermal storage medium in the spherical tank, which can completely avoid the risk of crystallization. The initial investment of the system is only about 60% of that of the molten salt thermal storage system. By coupling the electrode steam boiler with the spherical tank, the project cost and operational risk are significantly reduced, and the system safety and reliability are improved. 2) To meet the heating needs of multiple scenarios: Overcoming the limitation of traditional coupling technology in providing only one type of steam, this invention enables heating in multiple scenarios and operating modes, which can meet the steam demand of industrial production and ensure residential heating, thereby improving the diversity and adaptability of energy supply. 3) To improve heating capacity and reliability: This invention enhances the heating capacity of the unit during extremely cold periods, improves the reliability of the unit's heating supply, and ensures that the heating needs of residents and enterprises are stably guaranteed under extreme weather or special operating conditions. 4) Improve economic efficiency: Enhance opportunity cost conversion benefits by efficiently utilizing off-peak electricity to generate and store steam, transforming potentially idle off-peak electricity into high-value steam; simultaneously increase peak power generation revenue and capacity charge revenue, comprehensively improving the economic efficiency of energy utilization. 5) Respond to policies and energy development trends: Comply with national policies regarding the flexibility retrofitting of coal-fired power units, improvement of regulation capabilities, and optimization of the energy structure, contributing to the consumption of new energy sources and promoting the sustainable development of the energy industry.

[0009] To achieve the above objectives, this invention proposes a multi-scenario heating and thermoelectric decoupling system for electrode steam boilers and spherical tanks, including a water supply module, a steam preparation and storage module, and a heating network water heating module.

[0010] The water supply module includes a buffer tank, a spherical tank water supply pump, a deaerator water supply pump, and a deaerator.

[0011] The steam preparation and storage module includes a boiler feedwater pump, an electrode steam boiler, a high-pressure steam distributor, a spherical tank, a medium and low-pressure steam distributor, a steam heater, and a high-pressure electrode.

[0012] The heating network water heating module includes a heating network heater, a heating network circulating water pump, and a heating network drain pump.

[0013] The first water supply inlet of the buffer water tank is connected to the chemical demineralized water system via a pipeline; the second condensate inlet of the buffer water tank is connected to the main pipeline between the fourth condensate outlet of the heating network heater and the condensate inlet of the heating network condensate pump via a branch pipeline, and the branch pipeline is equipped with a low-pressure condensate branch electric gate valve.

[0014] The third water supply outlet of the buffer tank is connected to the water supply inlet of the spherical tank water supply pump via a pipeline; the water supply outlet of the spherical tank water supply pump is connected to the first water supply inlet of the spherical tank via a pipeline.

[0015] The fourth water outlet of the buffer tank is connected to the water inlet of the deaerator water supply pump via a pipeline; the water outlet of the deaerator water supply pump is connected to the first water inlet of the deaerator via a pipeline; the second steam inlet of the deaerator is connected to the fifth steam outlet of the medium-low pressure steam distribution cylinder via a pipeline, and the pipeline is equipped with a deaerator steam pressure reducing valve; the third condensate inlet of the deaerator is connected to the condensate outlet of the heating network condensate pump via a pipeline; the fourth feedwater outlet of the deaerator is connected to the feedwater inlet of the boiler feedwater pump via a pipeline; the feedwater outlet of the boiler feedwater pump is connected to the feedwater inlet of the electrode steam boiler via a pipeline; the electrode steam boiler is equipped with a high-voltage electrode, and the high-voltage electrode is connected to the generator output via an electrical circuit. The busbar can be optionally connected to the high-voltage switchyard; the steam outlet of the electrode steam boiler is connected to the first steam inlet of the high-pressure steam distributor via a pipeline; the second steam outlet of the high-pressure steam distributor is connected to the second steam inlet of the medium-low pressure steam distributor via a pipeline, and the pipeline is equipped with a boiler direct supply pressure reducing valve; the third steam outlet of the high-pressure steam distributor is connected to the second steam inlet of the spherical tank via a pipeline; a steam pipeline is led out from the third steam outlet of the spherical tank, and the pipeline is divided into two parallel pipelines, which are then merged into a single steam pipeline connected to the first steam inlet of the medium-low pressure steam distributor; wherein, the first pipeline is equipped with a high- and medium-pressure section flash pressure reducing valve, and the second pipeline is equipped with a medium- and low-pressure section flash pressure reducing valve.

[0016] The third steam outlet of the medium-low pressure steam distribution cylinder is connected to the steam inlet of the steam heater through a pipeline; the steam pipeline leading out of the steam outlet of the steam heater merges with the steam pipeline leading out of the industrial steam supply system of the cogeneration unit to form an industrial steam external supply main pipe for supplying industrial steam to the outside.

[0017] A steam pipe is led out from the fourth steam outlet of the medium and low pressure steam distribution cylinder. The pipe is divided into two parallel pipes, which are then merged into a single steam pipe connected to the first steam inlet of the heating network heater. The first pipe is equipped with a heating steam pressure reducing valve, and the second pipe is equipped with a heating steam direct-flow electric gate valve.

[0018] The circulating water pipe leading from the second hot water outlet of the heating network heater merges with the circulating water pipe leading from the outlet of the heating network water heating system of the cogeneration unit to form the main heating network circulating water supply pipe, which is used to provide residential heating.

[0019] The third hot water inlet of the heating network heater is connected to the hot water outlet of the heating network circulating water pump via a pipeline; the heating network circulating water pipeline connected to the hot water inlet of the heating network circulating water pump merges with the heating network circulating water pipeline connected to the inlet of the heating network water heating system of the cogeneration unit, and then they are connected together to the main return water pipe of the heating network circulating water.

[0020] In the multi-scenario heating and thermoelectric decoupling system of the electrode steam boiler and spherical tank, key equipment such as the deaerator, electrode steam boiler, high-pressure steam distribution cylinder, spherical tank, medium and low-pressure steam distribution cylinder, and heating network heater are all equipped with safety valves. When the pressure rises to the set pressure, the valves automatically open to release pressure, which can effectively prevent equipment damage or safety accidents caused by overpressure.

[0021] Preferably, the circulating water pump of the heating network can be equipped with a frequency converter or a hydraulic coupling, and the circulating water flow rate can be dynamically adjusted according to the real-time heat load of the heating network heater by using frequency conversion speed regulation or hydraulic coupling regulation.

[0022] In this embodiment, each device is configured as one unit. As an improvement to the technical solution, the multi-scenario heating and thermoelectric decoupling system of the electrode steam boiler and spherical tank can be flexibly set according to the actual storage and supply scale, equipment capacity and site conditions. Among them, the buffer water tank, spherical tank water supply pump, deaerator water supply pump, boiler feed water pump, electrode steam boiler, spherical tank, steam heater, heating network heater, heating network circulating water pump, heating network drain pump, etc. can be configured in parallel to achieve coordinated operation according to relevant standards, specifications, usage requirements and backup needs.

[0023] The beneficial effects of this invention are:

[0024] 1. Enhanced heating capacity: Significantly improves heating capacity. For example, in the case of a thermal power company, the direct heating capacity was greatly improved after the addition of an electrode steam boiler. Combined with the heat storage and release function of the spherical tank, the overall heating capacity of the system can be further enhanced.

[0025] 2. Enhanced heating reliability: Effectively enhances heating reliability, ensuring that heating capacity can be significantly maintained even if a single unit is out of service; the heat storage and release function of the spherical tank further improves the reliability of system operation.

[0026] 3. Enhanced peak-shaving capacity of the unit: The deep peak-shaving capacity of the unit is greatly enhanced. During both heating and non-heating seasons, the peak-shaving power output of the unit can be significantly reduced while maintaining the unit's operating mode and heating load, thereby improving the unit's flexibility in responding to the grid's peak-shaving needs.

[0027] 4. Increased peak power output of the unit: By storing and releasing heat, the spherical tank can supplement the unit with additional steam under different operating conditions, thereby increasing the peak power output of the unit.

[0028] 5. Improved energy efficiency: The system achieves rational conversion and allocation of electrical and thermal energy. The electrode steam boiler generates steam using off-peak electricity, while the spherical tank stores thermal energy simultaneously, reducing the power generation load loss caused by heating during peak hours. By balancing the heat load demand at different times, the spherical tank reduces energy waste and improves overall energy efficiency.

[0029] 6. Facilitating the absorption of new energy: Enhance the capacity to absorb new energy. Electrode steam boilers consume the electricity generated by coal-fired power units, improve the deep peak-shaving capacity of the units, and free up grid connection space for new energy power generation. This is equivalent to simultaneously and indirectly absorbing surplus new energy electricity and converting it into thermal energy storage, reducing dependence on coal-fired power generation and promoting the optimization and upgrading of the energy structure. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0031] Figure 1 This is a schematic diagram of the multi-scenario heating and thermoelectric decoupling system of the electrode steam boiler and spherical tank of the present invention;

[0032] Figure label:

[0033] 1-Makeup water module; 1.1-Buffer water tank; 1.2-Spherical tank makeup water pump; 1.3-Deaerator makeup water pump; 1.4-Deaerator; 2-Steam preparation and storage module; 2.1-Boiler feed water pump; 2.2-Electrode steam boiler; 2.3-High-pressure steam distributor; 2.4-Spherical tank; 2.5-Medium and low-pressure steam distributor; 2.6-Steam heater; 2.7-High-pressure electrode; 3-Heating network water heating module; 3.1-Heating network heater; 3.2-Heating network circulating water pump; 3.3-Heating network drain pump; 4.1-Heating steam pressure reducing valve; 4.2-Heating steam direct electric gate valve; 4.3-Low-pressure drain branch electric gate valve; 4.4-Deaerator steam pressure reducing valve. Detailed Implementation

[0034] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0035] Unless otherwise expressly specified and limited, the terms "first, second, third, fourth or fifth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; the terms "connected" or "linked" should be interpreted broadly, for example: they can be fixed connections, detachable connections or integral connections, they can be mechanical connections, electrical connections or direct connections, they can also be indirect connections through an intermediate medium, or they can be the internal connection of two components.

[0036] like Figure 1As shown, the present invention discloses a multi-scenario heating and thermoelectric decoupling system for electrode steam boilers and spherical tanks (through thermal energy storage and distribution, independent regulation of power generation and heating systems is achieved, improving unit flexibility), including a water supply module 1, a steam preparation and storage module 2, and a heating network water heating module 3.

[0037] The water supply module 1 includes a buffer tank 1.1, a spherical tank water supply pump 1.2, a deaerator water supply pump 1.3, and a deaerator 1.4;

[0038] The steam preparation and storage module 2 includes a boiler feedwater pump 2.1, an electrode steam boiler 2.2, a high-pressure steam distributor 2.3, a spherical tank 2.4, a medium and low-pressure steam distributor 2.5, a steam heater 2.6, and a high-pressure electrode 2.7;

[0039] The heating network water heating module 3 includes a heating network heater 3.1, a heating network circulating water pump 3.2, and a heating network drain pump 3.3;

[0040] The first water supply inlet of the buffer water tank 1.1 is connected to the chemical demineralized water system via a pipeline; the second drainage inlet of the buffer water tank 1.1 is connected to the main pipeline between the fourth drainage outlet of the heating network heater 3.1 and the drainage inlet of the heating network drainage pump 3.3 via a branch pipeline, and the branch pipeline is equipped with a low-pressure drainage branch electric gate valve 4.3;

[0041] The third water supply outlet of the buffer tank 1.1 is connected to the water supply inlet of the spherical tank water supply pump 1.2 via a pipeline; the water supply outlet of the spherical tank water supply pump 1.2 is connected to the first water supply inlet of the spherical tank 2.4 via a pipeline.

[0042] The fourth water outlet of the buffer water tank 1.1 is connected to the water inlet of the deaerator water supply pump 1.3 via a pipeline; the water outlet of the deaerator water supply pump 1.3 is connected to the first water inlet of the deaerator 1.4 via a pipeline; the second steam inlet of the deaerator 1.4 is connected to the fifth steam outlet of the medium-low pressure steam distribution cylinder 2.5 via a pipeline, and the pipeline is equipped with a deaerator steam pressure reducing valve 4.4; the third condensate inlet of the deaerator 1.4 is connected to the condensate outlet of the heating network condensate pump 3.3 via a pipeline; the fourth feedwater outlet of the deaerator 1.4 is connected to the feedwater inlet of the boiler feedwater pump 2.1 via a pipeline; the feedwater outlet of the boiler feedwater pump 2.1 is connected to the feedwater inlet of the electrode steam boiler 2.2 via a pipeline; the electrode steam boiler 2.2 is equipped with a high-voltage electrode 2.7, and the high-voltage electrode 2.7 is connected to the electrode via an electrical circuit. The generator outlet busbar is connected, optionally, to the high-voltage switchyard bay; the steam outlet of the electrode steam boiler 2.2 is connected to the first steam inlet of the high-pressure steam distributor 2.3 via a pipeline; the second steam outlet of the high-pressure steam distributor 2.3 is connected to the second steam inlet of the medium-low pressure steam distributor 2.5 via a pipeline, and the pipeline is equipped with a boiler direct supply pressure reducing valve 2.83; the third steam outlet of the high-pressure steam distributor 2.3 is connected to the second steam inlet of the spherical tank 2.4 via a pipeline; a steam pipeline is led out from the third steam outlet of the spherical tank 2.4, and the pipeline is divided into two parallel pipelines, which are then merged into a single steam pipeline connected to the first steam inlet of the medium-low pressure steam distributor 2.5; wherein, the first pipeline is equipped with a high-medium pressure section flash pressure reducing valve 2.81, and the second pipeline is equipped with a medium-low pressure section flash pressure reducing valve 2.82.

[0043] The third steam outlet of the medium-low pressure steam distribution cylinder 2.5 is connected to the steam inlet of the steam heater 2.6 through a pipeline; the steam pipeline leading out of the steam outlet of the steam heater 2.6 merges with the steam pipeline leading out of the industrial steam supply system of the cogeneration unit to form an industrial steam external supply main pipe for supplying industrial steam to the outside.

[0044] A steam pipe is led out from the fourth steam outlet of the medium and low pressure steam distribution cylinder 2.5. The pipe is divided into two parallel pipes, which are then merged into a single steam pipe and connected to the first steam inlet of the heating network heater 3.1. The first pipe is equipped with a heating steam pressure reducing valve 4.1, and the second pipe is equipped with a heating steam direct-flow electric gate valve 4.2.

[0045] The circulating water pipe leading from the second hot water outlet of the heating network heater 3.1 merges with the circulating water pipe leading from the outlet of the heating network water heating system of the cogeneration unit to form the main heating network circulating water supply pipe, which is used to provide residential heating.

[0046] The third hot water inlet of the heating network heater 3.1 is connected to the hot water outlet of the heating network circulating water pump 3.2 via a pipe; the heating network circulating water pipe connected to the hot water inlet of the heating network circulating water pump 3.2 merges with the heating network circulating water pipe connected to the inlet of the heating network water heating system of the cogeneration unit, and then they are connected together to the main return water pipe of the heating network circulating water.

[0047] In the multi-scenario heating and thermoelectric decoupling system of the electrode steam boiler and spherical tank, key equipment such as the deaerator 1.4, electrode steam boiler 2.2, high-pressure steam distribution cylinder 2.3, spherical tank 2.4, medium and low-pressure steam distribution cylinder 2.5, and heating network heater 3.1 are all equipped with safety valves. When the pressure rises to the set pressure, the valves automatically open to release pressure, which can effectively prevent equipment damage or safety accidents caused by overpressure.

[0048] Preferably, the heating network circulating water pump 3.2 can be equipped with a frequency converter or a hydraulic coupling, and the circulating water flow rate can be dynamically adjusted according to the real-time heat load of the heating network heater by using frequency conversion speed regulation or hydraulic coupling regulation.

[0049] In this embodiment, each device is configured as a single unit. As an improvement to the technical solution, the multi-scenario heating and thermoelectric decoupling system of the electrode steam boiler and spherical tank can be flexibly set according to the actual storage and supply scale, equipment capacity and site conditions. Among them, the buffer water tank 1.1, spherical tank water supply pump 1.2, deaerator water supply pump 1.3, boiler feed water pump 2.1, electrode steam boiler 2.2, spherical tank 2.4, steam heater 2.6, heating network heater 3.1, heating network circulating water pump 3.2, heating network drain pump 3.3, etc., can be configured in parallel with multiple units according to relevant standards and specifications, usage requirements and backup needs. When multiple devices are connected in parallel, the load is dynamically distributed through shared signals and heat load feedback data. When a single device fails, it automatically switches to the backup device.

[0050] Working process of this invention:

[0051] For ease of analysis, the influence of pressure drop is ignored, and the following steam pressure parameters are set: PH for high pressure, PM for medium pressure, and PL for low pressure for steam-water medium.

[0052] To facilitate system parameter quantification and operating condition analysis, the pressure parameters of the steam-water medium are defined as follows: high-pressure state pressure value is denoted as PH, medium-pressure state pressure value is denoted as PM, and low-pressure state pressure value is denoted as PL. These parameters need to be specifically set according to the actual application scenario (such as industrial steam supply, residential heating) heat demand and the rated pressure range of the equipment (for example, in this system, the rated steam pressure of the electrode steam boiler is 3.1 MPa.g (.g indicates gauge pressure, the rest are the same), corresponding to high pressure PH; the commonly used parameter for industrial steam is 0.8 MPa.g, corresponding to medium pressure PM; the commonly used parameter for heating steam is 0.4 MPa.g, corresponding to low pressure PL).

[0053] The chemically demineralized water output from the chemical demineralized water system, along with one of the two streams of heat network condensate (essentially chemically demineralized water) generated by the heat network heater 3.1, is initially stored together in the buffer tank 1.1. The demineralized water in the buffer tank 1.1 is distributed via two paths: one path is transported to the spherical tank 2.4 via the spherical tank makeup water pump 1.2; the other path is sent to the deaerator 1.4 via the deaerator makeup water pump 1.3, where it mixes and exchanges heat with the deaerated heating steam from the medium and low pressure steam distribution cylinder 2.5. After deaeration, it becomes feedwater, which is then transported to the electrode steam boiler 2.2 by the boiler feedwater pump 2.1.

[0054] Feedwater is heated by high-pressure electrode 2.7 in electrode steam boiler 2.2 to generate high-pressure saturated steam at pressure PH. This high-pressure saturated steam enters high-pressure steam separator 2.3 and is divided into two outputs: the first high-pressure steam is reduced to medium-pressure steam at pressure PM by boiler direct supply pressure reducing valve 2.83, and then sent to medium and low-pressure steam separator 2.5; the second high-pressure steam is directly introduced into spherical tank 2.4, and through heat exchange, the low-pressure medium in spherical tank 2.4 is heated into high-parameter saturated water and saturated steam, thereby completing the heat storage process.

[0055] The heat release process of spherical tank 2.4 is achieved through the following path: the stored high-parameter medium is led out through a main pipe and then divided into two paths for flash evaporation and pressure reduction to adapt to different pressure requirements. The first path is used to reduce the medium inside spherical tank 2.4 from high pressure (PH) to medium pressure (PM). After flash evaporation and pressure reduction by the high-medium pressure section flash evaporation and pressure reduction valve 2.81, it is converted into medium-pressure steam at PM and sent to the medium-low pressure steam distribution cylinder 2.5. The second path is used to reduce the medium inside spherical tank 2.4 from high pressure (PM) to medium pressure (PL). After flash evaporation and pressure reduction by the medium-low pressure section flash evaporation and pressure reduction valve 2.82, it is converted into low-pressure steam at PL and also sent to the medium-low pressure steam distribution cylinder 2.5.

[0056] The steam output from the medium-low pressure steam distribution cylinder 2.5 is divided into three paths: the first path is medium-pressure steam at a pressure of PM, which is heated by the steam heater 2.6 and then merged with the steam output from the industrial steam supply system of the cogeneration unit to supply industrial steam to the outside; the second path is the steam that was previously sent to the deaerator 1.4 for heating and deoxygenation; the third path is first divided into two branches (the first branch reduces the medium-pressure steam to low-pressure heating steam at a pressure of PL, and the second branch is a direct low-pressure steam at a pressure of PL), and then merged into one heating steam. This low-pressure heating steam is input into the heating network heater 3.1 to heat the heating network circulating water and is itself cooled into heating network condensate. After the condensate from the heating network is discharged, it is divided into two paths: one path is sent to the deaerator 1.4 via the heating network condensate pump 3.3; the other path is sent to the buffer tank 1.1 for buffering, where it is mixed with the chemical demineralized water provided by the chemical demineralized water system, and then sent to the spherical tank 2.4 and the deaerator 1.4 respectively via the spherical tank makeup water pump 1.2 and the deaerator makeup water pump 1.3, repeating the above cycle process.

[0057] The low-temperature circulating water return from the main circulating water supply pipe of the heating network is divided into two paths: one path is sent to the heating network heater 3.1 via the circulating water pump 3.2, where it is heated by heating steam to become high-temperature circulating water supply; the other path is upgraded by the heating network water heating system of the cogeneration unit to become high-temperature circulating water supply. After the two high-temperature circulating water supply paths merge, they are supplied to the public for residential heating via the main circulating water supply pipe.

[0058] Through the above working process, the electrode steam boiler and spherical tank multi-scenario heating and thermoelectric decoupling system of the present invention can realize the complete process of demineralized water replenishment, steam preparation, heat storage, multi-scenario steam distribution and external steam supply; the coordinated action of each device and valve can ensure the stable operation of the medium under different parameter conditions and flow paths.

[0059] The operating mode and corresponding operation process of this invention:

[0060] The operating modes of this invention are as follows: direct industrial steam supply from the electrode steam boiler; direct residential heating supply from the electrode steam boiler; steam supply from the electrode steam boiler to the spherical tank for heat storage; flash steam generation of medium-pressure steam in the spherical tank to supply industrial steam; and flash steam generation of low-pressure steam in the spherical tank to supply residential heating. The commissioning procedures for each mode are as follows:

[0061] 1) The process of direct industrial steam supply from electrode steam boiler is as follows: the chemically demineralized water in buffer tank 1.1 passes through deaerator makeup water pump 1.3, deaerator 1.4, and boiler feed water pump 2.1 in sequence. After being pressurized and deaerated, it becomes high-pressure feed water and enters electrode steam boiler 2.2. The generated steam passes through high-pressure steam distributor 2.3, boiler direct supply pressure reducing valve 2.83, medium and low pressure steam distributor 2.5, and steam heater 2.6 in sequence before being supplied to the outside as industrial steam.

[0062] 2) The direct supply process of the electrode steam boiler for residential heating is as follows: Heat network condensate flows sequentially through heat network condensate pump 3.3, deaerator 1.4, and boiler feedwater pump 2.1, becoming high-pressure feedwater that enters the electrode steam boiler 2.2. The generated steam flows sequentially through high-pressure steam distributor 2.3, boiler direct supply pressure reducing valve 2.83, medium and low-pressure steam distributor 2.5, and heating steam pressure reducing valve 4.1, becoming heating steam that is input into the heat network heater 3.1. While heating the heat network circulating water, the steam itself is cooled to become heat network condensate. This condensate is sent to the deaerator via heat network condensate pump 3.3, heated and deaerated, and then sent to the electrode steam boiler 2.2 via boiler feedwater pump 2.1, forming a cycle. The low-temperature heat network circulating water return is heated by the heat network heater 3.1 to become high-temperature heat network circulating water for supply to the public for residential heating. In this operating mode, the low-pressure condensate branch electric gate valve 4.3 is in the closed state.

[0063] 3) Electrode steam boiler supplies steam to spherical tank for heat storage: The chemically demineralized water in buffer tank 1.1 passes through deaerator makeup water pump 1.3, deaerator 1.4, and boiler feed water pump 2.1 in sequence. After being pressurized and deaerated, it becomes high-pressure feed water and enters electrode steam boiler 2.2. The generated steam passes through high-pressure steam distributor 2.3 and is then transported to spherical tank 2.4, where it mixes and exchanges heat with the low-parameter medium in the tank, transforming into a high-pressure saturated medium to complete heat storage.

[0064] 4) Spherical tank flash evaporation of medium-pressure steam to supply industrial steam: As the heat release process of the spherical tank 2.4 proceeds, the medium inside it drops from high pressure PH to medium pressure PM. Part of the medium is flashed and depressurized by the high-medium pressure section flash evaporation pressure reducing valve 2.81 and outputs medium-pressure steam at PM. This steam is then distributed by the medium-low pressure steam distribution cylinder 2.5 and conditioned by the steam heater 2.6 before being supplied as qualified industrial steam.

[0065] 5) Low-pressure steam supply for residential heating via flash evaporation in spherical tank 2.4: As the heat release process in spherical tank 2.4 proceeds, the medium inside decreases from high pressure (PM) to medium pressure (PL). Part of the medium is flashed and depressurized by the low-pressure section flash evaporation pressure reducing valve 2.82, outputting low-pressure steam at PL. This steam is then distributed sequentially through the low-pressure steam distribution cylinder 2.5 and fed into the heating network heater 3.1 via the heating steam direct-connection electric gate valve 4.2. While heating the heating network circulating water, the steam itself is cooled to become heating network condensate. The condensate flows back to the buffer tank 1.1 for storage via the low-pressure condensate branch electric gate valve 4.3. The low-temperature heating network circulating water return is heated by the heating network heater 3.1 to become high-temperature supply water, which is then provided for residential heating. In this operating mode, the heating network condensate pump 3.3 is shut down.

[0066] The amount of water replenished to buffer tank 1.1 by the chemical demineralized water system needs to be calculated comprehensively based on the dynamic steam and water loss under the aforementioned different operating modes, combined with the inherent steam and water loss of the system, to achieve dynamic matching of the replenishment amount.

[0067] The timing and operation mode of this invention under different peak-shaving conditions:

[0068] 1) When the heating season encounters extremely cold weather that leads to insufficient heating capacity of thermal power units, the electrode steam boiler should be put into operation to directly supply residential heating.

[0069] 2) When a heating capacity gap is caused by the shutdown of a single unit during the heating season, the electrode steam boiler should be put into operation to directly supply residential heating.

[0070] 3) When the unit is in deep peak shaving and the electricity price is at its lowest point, the electrode steam boiler should be put into operation in the mode of directly supplying industrial steam; if the electrode steam boiler has a surplus of steam, the electrode steam boiler can be put into operation in the mode of supplying steam to the spherical tank thermal storage.

[0071] 4) When the unit is at its peak and the electricity price is at its peak, the industrial steam supply mode of spherical tank flash steam medium-pressure steam supply should be put into operation.

[0072] 5) When the unit is at its peak and the electricity price is at its peak, if there is a surplus of medium-pressure steam, it can be used for residential heating, based on the existing industrial steam supply mode of spherical tank flash steam supply.

[0073] 6) When the unit is at its peak and the electricity price is at its peak, after the medium-pressure steam in the spherical tank has finished flashing, it should switch to the mode of supplying residential heating by flashing low-pressure steam in the spherical tank.

[0074] Example 1 of switching operation modes during the heating season:

[0075] When the unit is in deep peak shaving and the electricity price is at its lowest point, and the rated steam output of the electrode steam boiler is greater than the real-time industrial steam demand, the electrode steam boiler direct industrial steam supply mode and the electrode steam boiler steam supply to the spherical tank thermal storage mode are simultaneously activated. When the deep peak shaving and the electricity price at its lowest point end, and the unit enters peak period and the electricity price is at its highest point, the electrode steam boiler direct industrial steam supply mode and the electrode steam boiler steam supply to the spherical tank thermal storage mode are simultaneously deactivated, and the spherical tank flash evaporation of medium-pressure steam to supply industrial steam mode is activated. If there is surplus medium-pressure steam, the surplus portion is depressurized by the heating steam pressure reducing valve and sent to the heating network heater as heating steam for residential heating. After the spherical tank medium-pressure steam flash evaporation is completed, the system should switch to the spherical tank flash evaporation of low-pressure steam to supply residential heating mode until the medium pressure in the spherical tank drops to the low-pressure parameter (PL) or the unit peak period and the electricity price at its highest point end, completing one operating cycle.

[0076] Example 2 of switching operation mode during non-heating season:

[0077] During the non-heating season, only the industrial steam demand needs to be met. During non-heating season operation, the heating network circulating water pump (3.2), heating steam pressure reducing valve (4.1), and heating steam direct electric gate valve (4.2) are all closed, and the heating network water heating module (3) stops operating. When the unit is in a deep peak shaving period and the electricity price is in a low period, and the rated steam production of the electrode steam boiler is greater than the real-time industrial steam demand, the electrode steam boiler direct industrial steam supply mode and the electrode steam boiler steam supply to the spherical tank heat storage mode are simultaneously put into operation. When the deep peak shaving period and the electricity price in a low period ends, and the peak period and the electricity price in a high period end, the electrode steam boiler direct industrial steam supply mode and the electrode steam boiler steam supply to the spherical tank heat storage mode are simultaneously exited, and the spherical tank flash steam medium-pressure steam supply industrial steam mode is put into operation until the medium pressure in the spherical tank drops to the medium pressure parameter (PM) or the peak period of the unit and the electricity price in a high period ends, completing one operating cycle.

[0078] Example 3 of a multi-scenario heating and thermoelectric decoupling system for electrode steam boilers and spherical tanks:

[0079] A thermal power company is equipped with two 330MW subcritical cogeneration units, providing both residential heating and industrial steam supply. The industrial steam parameters are 0.8MPa.g, 280℃, and 65t / h. The company plans to adopt a multi-scenario heating and thermal-electric decoupling system using electrode steam boilers and spherical tanks, configuring two 20kV / 70MW electrode steam boilers and four 850m³ / h spherical tanks. 3 Spherical tank. The electrode steam boiler has a rated steam pressure of 3.1 MPa.g, and the spherical tank's working pressure is matched to this pressure. It is designed with a filling factor of 0.90. The commissioning of this system will bring the following significant benefits:

[0080] Firstly, heating capacity is significantly improved. With the addition of two 70MW electrode steam boilers to the existing two 330MW subcritical cogeneration units, the direct heating capacity can be increased by 140MW. Furthermore, by combining the heat storage and release functions of the spherical tanks and utilizing the characteristic that daytime temperatures are higher than nighttime temperatures, the flexible scheduling of heat storage and release through the spherical tanks can further enhance heating capacity.

[0081] Secondly, the reliability of heating supply is effectively enhanced. With two 330MW subcritical cogeneration units paired with two 70MW electrode steam boilers, when a single unit is operating, the direct heating capacity of the two 70MW electrode steam boilers is limited to 125MW due to the maximum selection current of 4000A for the 20kV busbar tie switchgear. After the system is put into operation, even if one unit is shut down, the heating capacity can still be increased by 125MW compared to without this system, which translates to an improvement in heating supply reliability of at least 6.9%. Furthermore, the heat storage and release function of the spherical tank can further enhance the reliability of heating supply.

[0082] Third, the unit's deep peak-shaving capability is significantly enhanced. During the heating season, when the unit's peak load is shaving to 40% Pe (Pe represents the unit's rated power generation load, and so on) and it is in heating mode, after configuring the multi-scenario heating and heat-electric decoupling system of the electrode steam boiler and spherical tank, under the premise of keeping the unit's own operating mode and heating load unchanged, the two 70MW electrode steam boilers can add an additional 140MW of direct supply and thermal storage load, while reducing the unit's peak-shaving depth from 40% Pe to 18.8% Pe. During the non-heating season, the system's deep peak-shaving advantage is also prominent. When the unit's peak load is 30% Pe and it is in heating mode, relying on the multi-scenario heating and thermoelectric decoupling system of the electrode steam boiler and spherical tank, while maintaining the stability of the unit's own operation mode and heating load, the two 70MW electrode steam boilers can add an additional 140MW of direct supply and thermal storage load, further reducing the unit's peak load depth from 30% Pe to 8.8% Pe. After deducting plant power consumption, it can achieve near-zero power grid connection, significantly improving the unit's flexibility in responding to grid peak load demands. By reducing the ineffective power generation consumption of high-priced coal during off-peak and low-electricity-price periods and converting it into high-value steam supply, the operating losses in this scenario can be effectively reduced.

[0083] Fourth, the thermal storage capacity is considerable. Four 850m³ units 3 The total volume of the spherical tank is 3400 m³. 3 Filling coefficient 0.9, actual volume 3060m³ 3 The relevant parameters for the high-pressure pH, medium-pressure PM, and low-pressure PL of the spherical tank are as follows:

[0084] At a pressure of 3.1 MPa, the density of saturated water is 817 kg / m³. 3 Enthalpy 1025 kJ / kg, mass 624943 kg (single tank); high pressure 3.1 MPa.g, saturated steam density 16.02 kg / m³ 3 Enthalpy value 2802kJ / kg, mass 1361kg (single tank).

[0085] The density of saturated water at a medium pressure of 0.8 MPa·g is 897 kg / m³. 3 Enthalpy 743 kJ / kg, mass 537,898 kg (single tank); medium pressure 0.8 MPa.g saturated steam density 4.16 kg / m³ 3 Enthalpy value 2772kJ / kg, mass 1149kg (single tank).

[0086] The density of saturated water at low pressure (0.4 MPa·g) is 915 kg / m³. 3 Enthalpy 640 kJ / kg, mass 510686 kg (single tank); low pressure 0.4 MPa.g saturated vapor density 2.67 kg / m³ 3 Enthalpy value 2748kJ / kg, mass 779kg (single tank).

[0087] The medium inside the four spherical tanks decreased from 3.1 MPa.g to 0.8 MPa.g, and the single heat release capacity was 268 MWh.

[0088] The calculation process is as follows:

[0089] [(1025×624943+2802×1361)-(743×537898+2772×1149)]÷1000÷3600×4=268MWh;

[0090] The medium inside the four spherical tanks decreased from 3.1 MPa.g to 0.4 MPa.g, with a single heat release capacity of 350 MWh.

[0091] The calculation process is as follows:

[0092] [(1025×624943+2802×1361)-(640×510686+2748×779)]÷1000÷3600×4=350MWh.

[0093] Thus, the heat storage capacity of the four spherical tanks for medium-pressure steam release flash evaporation is 268MWh, and the heat storage capacity for low-pressure steam release flash evaporation is further increased to 350MWh, an increase of 30.6%.

[0094] Fifth, the peak power generation output of the unit is improved. The thermal storage capacity of the medium-pressure steam released by the four spherical tanks is 268MWh, and the thermal storage capacity of the low-pressure steam released by further heat release is increased to 350MWh, an increase of 30.6%. When the medium-pressure steam released by the spherical tanks is used to supply industrial steam, and the heat release steam supply flow rate is 65t / h, the peak power generation output of the unit can be increased by 9.168MW; while when the medium-pressure steam in the spherical tanks is finished and the system switches to the low-pressure steam released by the spherical tanks to supply residential heating, the peak power generation output of the unit can be increased by 6.530MW, again calculated at the same heat release steam supply flow rate of 65t / h. This system meets the heat load by releasing steam during peak hours in the spherical tanks, reduces the loss of power generation load due to heating, increases the amount of electricity fed into the grid at peak price and the revenue from capacity charges, and creates significant economic returns for enterprises.

[0095] Sixth, energy efficiency is improved. Electrode steam boilers can utilize off-peak electricity for heating and steam production, which is then stored in spherical tanks. This reduces power generation load losses during peak electricity consumption periods, achieving a rational conversion and allocation of electrical and thermal energy, and reducing energy waste. Simultaneously, the heat storage and release function of the spherical tanks balances heat load demands at different times, allowing the unit to operate under optimal conditions and reducing energy consumption increases caused by load fluctuations, thereby improving overall energy efficiency.

[0096] Seventh, it enhances the capacity for absorbing new energy sources. As the proportion of new energy power generation continues to increase, its inherent volatility poses a significant challenge to the stable operation of the power grid. In this system, the electrode steam boiler, by consuming the electricity generated by coal-fired power units, can further enhance the deep peak-shaving capacity of the units, freeing up valuable grid connection space for new energy power generation, thereby directly contributing to the absorption of new energy. This process is equivalent to indirectly absorbing the surplus electricity generated by new energy power generation and converting it into heat energy stored in the spherical tank; when new energy power generation is insufficient, heat can be released through the spherical tank to meet heating demand, reducing dependence on coal-fired power units, and thus indirectly increasing the absorption of new energy, providing strong support for the optimization and upgrading of the energy structure.

[0097] The foregoing descriptions are merely illustrative of certain exemplary embodiments of the present invention. Those skilled in the art can make various modifications to the embodiments without departing from their spirit and scope. Therefore, the above figures and descriptions are illustrative in nature and do not constitute a limitation on the scope of the claims. The present invention is not limited to the above embodiments. Any product derived by any person under its guidance, with a technical solution that is the same as or similar to this application, regardless of changes in shape or structure, is within the scope of protection.

Claims

1. A multi-scenario heating and thermoelectric decoupling system for an electrode steam boiler and a spherical tank, characterized in that, It includes a water supply module (1), a steam preparation and storage module (2), and a heating network water heating module (3); The water supply module (1) includes a buffer tank (1.1), a spherical tank water supply pump (1.2), a deaerator water supply pump (1.3), and a deaerator (1.4). The buffer tank (1.1) provides water supply to the spherical tank (2.4) and the deaerator (1.4) respectively, and at the same time receives part of the heat network condensate generated by the heat network heater (3.1). The steam preparation and storage module (2) includes a boiler feedwater pump (2.1), an electrode steam boiler (2.2), a high-pressure steam distributor (2.3), a spherical tank (2.4), a medium and low-pressure steam distributor (2.5), a steam heater (2.6), and a high-pressure electrode (2.7); The heating network water heating module (3) includes a heating network heater (3.1), a heating network circulating water pump (3.2), and a heating network drain pump (3.3); The first water supply inlet of the buffer water tank (1.1) is connected to the chemical demineralized water system via a pipeline; the second condensate inlet of the buffer water tank (1.1) is connected to the main pipeline between the fourth condensate outlet of the heating network heater (3.1) and the condensate inlet of the heating network condensate pump (3.3) via a branch pipeline, and the branch pipeline is equipped with a low-pressure condensate branch electric gate valve (4.3); The third water supply outlet of the buffer tank (1.1) is connected to the water supply inlet of the spherical tank water supply pump (1.2) via a pipeline; the water supply outlet of the spherical tank water supply pump (1.2) is connected to the first water supply inlet of the spherical tank (2.4) via a pipeline; The fourth water outlet of the buffer tank (1.1) is connected to the water inlet of the deaerator water pump (1.3) via a pipeline; the water outlet of the deaerator water pump (1.3) is connected to the first water inlet of the deaerator (1.4) via a pipeline; the second steam inlet of the deaerator (1.4) is connected to the fifth steam outlet of the medium and low pressure steam distribution cylinder (2.5) via a pipeline, and the pipeline is equipped with a deaerator steam pressure reducing valve (4.4); the third condensate inlet of the deaerator (1.4) is connected to the condensate outlet of the heating network condensate pump (3.3) via a pipeline; the fourth feedwater outlet of the deaerator (1.4) is connected to the feedwater inlet of the boiler feedwater pump (2.1) via a pipeline; the feedwater outlet of the boiler feedwater pump (2.1) is connected to the feedwater inlet of the electrode steam boiler (2.2) via a pipeline; the electrode steam boiler (2.2) is equipped with a high-pressure electrode (2.7), the high-pressure electrode ( 2.7) The generator outlet busbar or high-voltage switchyard is connected via an electrical circuit; the steam outlet of the electrode steam boiler (2.2) is connected to the first steam inlet of the high-pressure steam distributor (2.3) via a pipeline; the second steam outlet of the high-pressure steam distributor (2.3) is connected to the second steam inlet of the medium-low pressure steam distributor (2.5) via a pipeline, and the pipeline is equipped with a boiler direct supply pressure reducing valve (2.83); the third steam outlet of the high-pressure steam distributor (2.3) is connected to the second steam inlet of the spherical tank (2.4) via a pipeline; a steam pipeline is led out from the third steam outlet of the spherical tank (2.4), the pipeline is divided into two parallel pipelines, and then merged into a single steam pipeline connected to the first steam inlet of the medium-low pressure steam distributor (2.5); wherein, the first pipeline is equipped with a high- and medium-pressure section flash pressure reducing valve (2.81), and the second pipeline is equipped with a medium- and low-pressure section flash pressure reducing valve (2.82); The third steam outlet of the medium and low pressure steam distribution cylinder (2.5) is connected to the steam inlet of the steam heater (2.6) through a pipeline; the steam pipeline leading out of the steam outlet of the steam heater (2.6) merges with the steam pipeline leading out of the industrial steam supply system of the cogeneration unit to form the main external industrial steam supply pipeline. A steam pipe is led out from the fourth steam outlet of the medium and low pressure steam distribution cylinder (2.5). The pipe is divided into two parallel pipes, which are then merged into a single steam pipe and connected to the first steam inlet of the heating network heater (3.1). The first pipe is equipped with a heating steam pressure reducing valve (4.1), and the second pipe is equipped with a heating steam direct-flow electric gate valve (4.2). The circulating water pipe leading from the second hot water outlet of the heating network heater (3.1) merges with the circulating water pipe leading from the outlet of the heating network water heating system of the cogeneration unit to form the main water supply pipe for the circulating water of the heating network. The third hot water inlet of the heat network heater (3.1) is connected to the hot water outlet of the heat network circulating water pump (3.2) through a pipe; the heat network circulating water pipe connected to the hot water inlet of the heat network circulating water pump (3.2) merges with the heat network circulating water pipe connected to the inlet of the heat network water heating system of the cogeneration unit and is then connected to the main return water pipe of the heat network circulating water. Safety valves are provided in the deaerator (1.4), electrode steam boiler (2.2), high-pressure steam distributor (2.3), spherical tank (2.4), medium and low-pressure steam distributor (2.5), and heating network heater (3.1).

2. The system according to claim 1, characterized in that, The heating network circulating water pump (3.2) is equipped with a frequency converter or a hydraulic coupling.

3. The system according to claim 1, characterized in that, At least one of the following components—buffer tank (1.1), spherical tank water supply pump (1.2), deaerator water supply pump (1.3), boiler feed pump (2.1), electrode steam boiler (2.2), spherical tank (2.4), steam heater (2.6), heating network heater (3.1), heating network circulating water pump (3.2), and heating network drain pump (3.3)—is configured in parallel to achieve coordinated operation.

4. An operation method for a multi-scenario heating and thermoelectric decoupling system of an electrode steam boiler and a spherical tank, characterized in that, Based on the system according to any one of claims 1-3, The process includes the following: Makeup water treatment process: The chemically demineralized water output from the chemical demineralized water system and part of the heat network condensate generated by the heat network heater (3.1) are stored together in the buffer water tank (1.1). One path of the demineralized water in the buffer water tank (1.1) is transported to the spherical tank (2.4) via the spherical tank makeup water pump (1.2), and the other path is sent to the deaerator (1.4) via the deaerator makeup water pump (1.3). After mixing and exchanging heat with the deaerated heating steam from the medium and low pressure steam distribution cylinder (2.5), it becomes feed water and is transported to the electrode steam boiler (2.2) by the boiler feed water pump (2.1). Steam preparation and storage process: Feedwater is heated by high-pressure electrodes (2.7) in the electrode steam boiler (2.2) to generate high-pressure saturated steam. After entering the high-pressure steam separator (2.3), it is divided into two paths. The first path is reduced to medium-pressure steam parameters through the boiler direct supply pressure reducing valve (2.83) and sent to the medium-low pressure steam separator (2.5). The second path is directly connected to the spherical tank (2.4), where the low-pressure medium is heated to high-parameter saturated water and saturated steam to complete heat storage. Heat release process of spherical tank: The high-parameter medium stored in spherical tank (2.4) is led out through the main pipe and divided into two paths. The first path is flashed and depressurized into medium-pressure steam through the high-medium pressure section flash evaporation pressure reducing valve (2.81) and sent into the medium-low pressure steam distribution cylinder (2.5). The second path is flashed and depressurized into low-pressure steam through the medium-low pressure section flash evaporation pressure reducing valve (2.82) and sent into the medium-low pressure steam distribution cylinder (2.5). Steam supply process: The steam in the medium and low pressure steam distribution cylinder (2.5) is divided into three paths. The first path of medium pressure steam is heated by the steam heater (2.6) and then merged with the steam output from the industrial steam supply system of the cogeneration unit to supply industrial steam to the outside. The second path is sent to the deaerator (1.4) for heating and deoxygenation. The third path is divided into two branches and then merged into one heating steam input to the heating network heater (3.1), which heats the heating network circulating water and then cools itself to become heating network condensate. One path of the heating network condensate is sent to the deaerator (1.4) via the heating network condensate pump (3.3), and the other path is sent to the buffer water tank (1.1) for buffering. The process of circulating water in the heating network: The low-temperature circulating water return from the main heating network water return pipe is divided into two paths. One path is sent to the heating network heater (3.1) via the heating network circulating water pump (3.2) to be heated into high-temperature circulating water supply. The other path is upgraded by the heating network water heating system of the cogeneration unit to become high-temperature circulating water supply. After the two high-temperature circulating water supply paths are combined, they are used to provide residential heating through the main heating network water supply pipe.

5. The method according to claim 4, characterized in that, The operating modes include the first electrode steam boiler direct industrial steam supply mode. The process of this mode is as follows: the chemically demineralized water in the buffer tank (1.1) is deaerated and pressurized by the deaerator makeup water pump (1.3), deaerator (1.4), and boiler feed water pump (2.1) and then enters the electrode steam boiler (2.2). The generated steam is processed by the high-pressure steam distribution cylinder (2.3), the boiler direct supply pressure reducing valve (2.83), the medium and low pressure steam distribution cylinder (2.5), and the steam heater (2.6) and then supplied to the outside as industrial steam.

6. The method according to claim 4, characterized in that, The operating modes include the direct supply of domestic heating from the second electrode steam boiler. The process of this mode is as follows: the heat network condensate is deaerated and pressurized by the heat network condensate pump (3.3), deaerator (1.4), and boiler feed water pump (2.1) to become high-pressure feed water and enter the electrode steam boiler (2.2). The generated steam is depressurized by the high-pressure steam distribution cylinder (2.3), boiler direct supply pressure reducing valve (2.83), medium and low pressure steam distribution cylinder (2.5), and heating steam pressure reducing valve (4.1) and then input into the heat network heater (3.1). After heating the heat network circulating water, it is cooled to become heat network condensate and flows back to the heat network condensate pump (3.3) to form a cycle. The low-temperature heat network circulating water return water is heated by the heat network heater (3.1) and then supplied to the outside for domestic heating. The electric gate valve (4.3) of the low-pressure condensate branch is in the closed state.

7. The method according to claim 4, characterized in that, The operating modes include the electrode steam boiler supplying steam to the spherical tank for heat storage. The process of this mode is as follows: the chemically demineralized water in the buffer tank (1.1) is pressurized and deoxygenated by the deaerator makeup water pump (1.3), deaerator (1.4), and boiler feed water pump (2.1) and then enters the electrode steam boiler (2.2). The generated steam is transported to the spherical tank (2.4) through the high-pressure steam distributor (2.3) and mixed with the low-parameter medium in the tank for heat exchange, and is converted into a high-pressure saturated medium to complete the heat storage.

8. The method according to claim 4, characterized in that, The operating modes include the spherical tank flash evaporation medium-pressure steam supply mode for industrial steam. The process of this mode is as follows: the pressure of the high-pressure saturated medium in the spherical tank (2.4) drops to the medium-pressure parameter (PM) stage. After the medium-pressure medium is reduced and flashed by the high-medium pressure section flash evaporation pressure reducing valve (2.81), medium-pressure steam is output. It is then distributed by the medium-low pressure steam distribution cylinder (2.5) and conditioned by the steam heater (2.6) to provide industrial steam to the outside.

9. The method according to claim 4, characterized in that, The operating modes include the spherical tank flash evaporation low-pressure steam supply mode for residential heating. The process of this mode is as follows: the pressure of the medium-pressure saturated medium in the spherical tank (2.4) drops to the low-pressure parameter (PL) stage. After the medium-low pressure section flash evaporation pressure reducing valve (2.82) reduces pressure and flashes, the low-pressure parameter (PL) steam is output. It is then distributed through the medium-low pressure steam distribution cylinder (2.5) and sent to the heating network heater (3.1) through the heating steam direct electric gate valve (4.2). After heating the heating network circulating water, it is cooled to become heating network condensate. The condensate flows back to the buffer water tank (1.1) for storage through the low-pressure condensate branch electric gate valve (4.3). The low-temperature heating network circulating water return water is heated by the heating network heater (3.1) and then supplied to the outside for residential heating. The heating network condensate pump (3.3) is in a stopped state.

10. The method according to claim 4, characterized in that, The method operates under different peak-shaving conditions, including: When the heating season encounters extremely cold weather that leads to insufficient heating capacity of thermal power units, the second electrode steam boiler is put into operation to directly supply residential heating. When a heating capacity gap is caused by the shutdown of a single unit during the heating season, the second electrode steam boiler will be put into operation to directly supply residential heating. When the unit is in deep peak shaving and the electricity price is at its lowest, the first electrode steam boiler is put into operation to directly supply industrial steam. If the electrode steam boiler has a surplus of steam, the electrode steam boiler is put into operation simultaneously to supply steam to the spherical tank thermal storage mode. When the unit is at its peak and the electricity price is at its peak, the spherical tank flash medium-pressure steam supply mode is put into operation to supply industrial steam. When the unit is at its peak and the electricity price is at its peak, based on the operation of the spherical tank flash medium-pressure steam supply mode for industrial steam, if there is a surplus of medium-pressure steam, the surplus part is sent to the heating network heater (3.1) after being reduced in pressure by the heating steam pressure reducing valve (4.1) as heating steam for residential heating. When the unit is at its peak and the electricity price is at its peak, and after the medium-pressure steam in the spherical tank has finished flashing, the system switches to the mode of supplying residential heating with low-pressure steam from the spherical tank flashing.

Images