Heat supply system and method for standby heat source of heat supply network

Abstract

The invention provides a heat supply network standby heat source heat supply system and method, and belongs to the technical field of nuclear energy heat supply, the heat supply network standby heat source heat supply system comprises a CAP nuclear power heat supply unit and a heat supply network standby heat source subsystem, and the CAP nuclear power heat supply unit and the heat supply network standby heat source subsystem are both connected with a heat supply pipeline; a steam heat accumulator is further arranged, a steam extraction opening of a steam turbine intermediate pressure cylinder in the CAP nuclear power heat supply unit is connected with an air inlet of the steam heat accumulator through a heat accumulator steam filling adjusting valve, and a steam exhaust opening of the steam heat accumulator is connected with a steam inlet of a standby high-temperature heat source heater in the heat supply network standby heat source subsystem through a heat accumulator steam exhaust adjusting valve. The method has the emergency guarantee capability of accident shutdown in the heat supply period, and meanwhile, has higher flexibility and a more excellent energy-saving effect.

Description

Technical Field

[0001] The present invention belongs to the technical field of nuclear energy heating, and in particular relates to a heating network backup heat source heating system and method. Background Art

[0002] CAP nuclear power heating unit is a device that uses nuclear energy to provide heat. Its core principle is to provide heat through the nuclear energy released by the chain fission reaction in the nuclear reactor, which is then used for heating. This heating method is efficient and stable and can meet large-scale heating needs.

[0003] Traditional nuclear cogeneration does not technically take into account response plans for accidental shutdown conditions. In the event of an accidental shutdown of a nuclear heating unit during severe cold weather, the heating needs of users cannot be guaranteed.

[0004] At the same time, conventional nuclear energy cogeneration only uses steam to heat the water in the heat network. According to the second law of thermodynamics, the heat exchange temperature difference is large, the exergy loss is large, and the economic efficiency of the nuclear energy heating unit is reduced. In addition, the problem of deep peak regulation is not taken into account when cogenerating nuclear energy heat and power, and the flexibility is poor. Summary of the invention

[0005] In view of the defects or shortcomings in the prior art, the present invention provides a heating network backup heat source heating system and method, which has the emergency guarantee capability of accident shutdown during the heating period, and at the same time has higher flexibility and better energy-saving effect.

[0006] To achieve the above object, the present invention adopts the following technical solution: In a first aspect, an embodiment of the present invention provides a heat network standby heat source heating system, including a CAP nuclear power heating unit and a heat network standby heat source subsystem, wherein the CAP nuclear power heating unit and the heat network standby heat source subsystem are both connected to a heating pipeline; A steam accumulator is also provided. The steam extraction port of the intermediate pressure cylinder of the steam turbine in the CAP nuclear power heating unit is connected to the air inlet of the steam accumulator through the accumulator steam charging regulating valve, and the steam exhaust port of the steam accumulator is connected to the steam inlet of the standby high-temperature heat source heater in the standby heat source subsystem of the heating network through the accumulator steam exhaust regulating valve.

[0007] Furthermore, the CAP nuclear power heating unit includes a reactor, a steam generator, a steam turbine and a heat network heater, wherein the reactor is connected to the steam generator, the steam outlet of the steam generator is connected to the steam inlet of the intermediate pressure cylinder of the steam turbine, the exhaust port of the intermediate pressure cylinder is connected to the steam inlet of the low pressure cylinder, the steam turbine is also connected to the generator, and the intermediate pressure cylinder, the low pressure cylinder and the generator are coaxially arranged.

[0008] Furthermore, the steam extraction port of the intermediate pressure cylinder is connected to the steam inlet of the heat network heater through the intermediate exhaust steam extraction valve, and the water inlet and water outlet of the heat network heater are both connected to the heating pipeline.

[0009] Furthermore, the water inlet of the heating network heater is connected to the heating pipe through an inlet pipe, and a heating network heater inlet valve is provided on the inlet pipe. The water outlet of the heating network heater is connected to the heating pipe through an outlet pipe, and a heating network heater outlet valve is provided on the outlet pipe.

[0010] Furthermore, a backup heating network water valve is provided on the heating pipe between the water inlet pipe and the water outlet pipe.

[0011] Furthermore, the heat network backup heat source subsystem includes a backup high-temperature heat source heater, a backup low-temperature electric heater, a photovoltaic power generation system and an energy storage device, wherein the exhaust port of the steam accumulator is connected to the heat source steam inlet of the backup high-temperature heat source heater through the accumulator exhaust regulating valve, the power outlet of the photovoltaic power generation system is connected to the power inlet of the energy storage device, and the power outlet of the energy storage device is connected to the power inlet of the backup low-temperature electric heater.

[0012] Furthermore, the water inlet of the standby low-temperature electric heater is connected to the heating pipe through a standby water inlet pipe, and a standby heating network water inlet valve is provided on the standby water inlet pipe. The water outlet of the standby low-temperature electric heater is connected to the water inlet of the standby high-temperature heat source heater, and the water outlet of the standby high-temperature heat source heater is connected to the heating pipe through a standby water outlet pipe, and a standby heating network water outlet valve is provided on the standby water outlet pipe.

[0013] Furthermore, a heat network water valve is also provided on the heating pipe between the standby water inlet pipe and the standby water outlet pipe.

[0014] Furthermore, the photovoltaic power generation system adopts N-type heterojunction photovoltaic modules, and the energy storage device is a container-type energy storage power station using lithium iron phosphate battery packs.

[0015] In a second aspect, an embodiment of the present invention provides a method for supplying heat using a standby heat source in a heating network, using a standby heat source heating device for a heating network as described above, comprising the following steps: When the nuclear power unit is operating normally for heating and deep peak regulation, the accumulator steam charging regulating valve is opened to charge the excess steam into the steam accumulator, and the unit stores heat. At the same time, the accumulator exhaust regulating valve is closed, the standby low-temperature electric heater and the standby high-temperature heat source heater are shut down, and the integrated smart energy system operates normally. The electricity generated by the photovoltaic power generation system is stored in the energy storage device, the heating network heater water inlet valve and the heating network heater water outlet valve are opened, the standby heating network water valve is closed, the heating network heater is put into operation and assumes the heating load, the standby heating network water inlet valve and the standby heating network water outlet valve are closed, and the heating network water valve is opened to send the heated heating network water out; When a shutdown failure occurs during the heating period, the water inlet valve and the water outlet valve of the heating network heater are closed, the standby heating network water valve is opened, and the heating network heater is shut down; due to the shutdown of the unit, the steam charging regulating valve of the heat accumulator is closed, and at the same time the steam exhaust regulating valve of the heat accumulator is opened, the standby heating network water inlet valve and the standby heating network water outlet valve are opened, and the heating network water valve is closed. The integrated smart energy system performs primary heating on the heating network return water of the standby low-temperature electric heater, and the steam heat storage is secondary heated up by the standby high-temperature heat source heater before being sent to the heating network water supply pipeline.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention provides a heat network standby heat source subsystem, which provides heat source to the heating pipeline during an accident shutdown condition, thereby improving the guarantee capability of heat user load during shutdown conditions.

[0017] 2. The present invention provides a steam accumulator to store excess steam during deep peak regulation under normal operating conditions, and at the same time provides a heat source for the standby high-temperature heat source heater of the standby heat network loop when the reactor is shut down, thereby improving the flexibility of the nuclear energy heating unit.

[0018] 3. The present invention provides a standby low-temperature electric heater and a standby high-temperature heat source heater. When the unit is shut down due to a fault, the heat storage of the unit itself and the electric energy storage of the integrated intelligent energy system are used to ensure the heating needs of northern heat users under severe cold conditions. At the same time, the low-temperature electric heater is provided to preheat the return water of the heating network. The heated water in the heating network has a smaller heat exchange temperature difference when the standby high-temperature heat source heater exchanges heat with steam, which effectively saves energy and reduces consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the structure of a heat network standby heating system in Embodiment 1 of the present invention; Figure 2 This is a diagram showing the internal structure of a steam accumulator in Embodiment 1 of the present invention; Among them, 1. Reactor; 2. Steam generator; 3. Medium-pressure cylinder; 4. Low-pressure cylinder; 5. Generator; 6. Medium-exhaust steam extraction valve; 7. Regenerator steam charging regulating valve; 8. Heating network heater; 9. Heating network water circulation pump; 10. Heating network heater outlet valve; 11. Heating network heater inlet valve; 12. Standby heating network water valve; 13. Steam accumulator; 14. Regenerator exhaust steam regulating valve; 15. Standby high-temperature heat source heater; 16. Photovoltaic power generation system; 17. Energy storage device; 18. Standby low-temperature electric heater; 19. Standby heating network inlet valve; 20. Heating network water valve; 21. Standby heating network outlet valve; 22. Heating network return pipe; 23. Heating network water supply pipe; 24. Heating network standby heat source subsystem. DETAILED DESCRIPTION The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0020] Embodiment 1 A typical implementation of the present invention is as follows Figure 1 As shown, a heating network backup heat source heating system includes a CAP nuclear power heating unit and a heating network backup heat source subsystem 24, wherein the CAP nuclear power heating unit is a 1200MW and above capacity level, the CAP nuclear power heating unit and the heating network backup heat source subsystem 24 are both connected to a heating pipeline, one end of the heating pipeline is connected to a heating network return water pipeline 22, and the other end is connected to a heating network water supply pipeline 23.

[0021] Under normal operating conditions, the CAP nuclear power heating unit provides heat source for the heating pipeline. Under accident shutdown conditions, the heat network backup heat source subsystem 24 provides heat source for the heating pipeline.

[0022] The CAP nuclear power heating unit includes a reactor 1, a steam generator 2, a steam turbine and a heat network heater 8, wherein the reactor 1 is connected to the steam generator 2, the steam outlet of the steam generator 2 is connected to the steam inlet of the intermediate pressure cylinder 3 of the steam turbine, the exhaust port of the intermediate pressure cylinder 3 is connected to the steam inlet of the low pressure cylinder 4, the steam turbine is also connected to the generator 5, and the intermediate pressure cylinder 3, the low pressure cylinder 4 and the generator 5 are coaxially arranged.

[0023] The steam extraction port of the intermediate pressure cylinder 3 is connected to the steam inlet of the heat network heater 8 through the intermediate row steam extraction valve 6. The water inlet and the water outlet of the heat network heater 8 are both connected to the heating pipe. The water inlet of the heat network heater 8 is connected to the heating pipe through the water inlet pipe, and a heat network heater water inlet valve 11 is arranged on the water inlet pipe. The water outlet 8 of the heat network heater is connected to the heating pipe through the water outlet pipe, and a heat network heater water outlet valve 10 is arranged on the water outlet pipe. A standby heat network water valve 12 is arranged on the heating pipe between the water inlet pipe and the water outlet pipe.

[0024] Under normal heating conditions, the standby heating network water valve 12 is closed, and the heating network heater 8 is connected to the heating pipeline through the heating network heater outlet valve 10 and the heating network heater inlet valve 11, so that the heating network heater 8 is used to heat the heating network inlet water; under accident conditions, the heating network heater outlet valve 10 and the heating network heater inlet valve 11 are closed, and the standby heating network water valve 12 is opened. At this time, the heating network heater 8 is disconnected from the heating pipeline, and the heating network water supply is heated by the heating network standby heat source subsystem 24.

[0025] A heat network water circulation pump 9 is also provided on the heating pipeline to ensure water circulation in the heating pipeline.

[0026] A steam accumulator 13 is also provided, and the steam extraction port of the intermediate pressure cylinder 3 is also connected to the air inlet of the steam accumulator 13 through the accumulator steam charging regulating valve 7. The steam extraction amount of the intermediate pressure cylinder 3 is adjusted by changing the valve opening of the accumulator steam charging regulating valve 7. The steam exhaust port of the steam accumulator 13 is connected to the steam inlet of the standby high-temperature heat source heater 15 in the heat network standby heat source subsystem 24 through the accumulator steam exhaust regulating valve 14. The steam discharge amount of the steam accumulator 13 and the heat exchange amount in the standby high-temperature heat source heater 15 are adjusted by adjusting the opening of the accumulator steam exhaust regulating valve 14.

[0027] By adding a steam accumulator 13 to store excess steam during deep peak regulation, and at the same time providing a heat source as a standby high-temperature heat source heater 15 for a standby heat network loop when the reactor is shut down, the instantaneous charging and discharging characteristics of the steam accumulator 13 are used to improve the peak regulation response speed of the unit, and the steam stored in deep peak regulation is used as a heat source for emergency heating, thereby achieving energy level matching and energy saving and consumption reduction.

[0028] The saturated water enthalpy value in the steam accumulator 13 will change accordingly with the rise and fall of its pressure, thereby realizing the storage and release of thermal energy. The charging and exhausting rates are adjusted by the internal pressure and the pressure difference between the charging and exhausting pipes. By controlling the opening and closing states of the accumulator charging regulating valve 7 and the accumulator exhaust regulating valve 14, the charging and exhausting working modes can be further changed, thereby realizing the storage and release of thermal energy in the steam accumulator 13.

[0029] Specifically, Figure 2As shown, when the accumulator steam charging regulating valve 7 is opened, the extraction steam is discharged from port a into the steam accumulator 13, and the superheated steam is discharged into the water, releasing the latent heat of vaporization to the surrounding water, condensing itself, and raising the water temperature. There are two pressure changes in the container: ① When the water temperature rises, the corresponding saturation pressure also rises, and the water space pressure rises; ② At the beginning, due to the large temperature difference, most of the steam can fully exchange heat and condense, but there is still a small part of non-condensable steam escaping through the water space to the steam space, which increases the steam space pressure. As the process proceeds, the amount of non-condensable steam entering the steam space increases and the rate accelerates, and the steam space pressure further increases. When the steam space pressure rises to the same level as the steam source pressure, the steam charging ends and the water level rises. When the accumulator steam exhaust regulating valve 14 is opened, the pressure in the accumulator is originally higher than that in the outside world. At the moment the valve is opened, it is connected to the outside world, and the steam space pressure drops instantly, and the steam is discharged from the steam accumulator 13 from port b. As the steam is discharged, the pressure in the steam space continues to decrease. As the pressure decreases, it is lower than the saturated pressure corresponding to the saturated water stored in the accumulator. The saturated water becomes superheated water and flash evaporation occurs. Bubbles begin to form from many vaporization cores in the entire water space, which continuously evaporate into the steam space to replenish steam. Since the amount of steam discharged from the steam space is greater than the amount of steam replenished by water evaporation, the exhaust process is generally a process of lowering temperature, steam taking away heat, releasing heat, lowering pressure, and lowering water level. When the pressure in the steam space drops to the same level as the steam pressure, the exhaust ends.

[0030] The heat network backup heat source subsystem 24 includes a backup high-temperature heat source heater 15, a backup low-temperature electric heater 18, a photovoltaic power generation system 16 and an energy storage device 17, wherein the exhaust port of the steam accumulator 13 is connected to the heat source steam inlet of the backup high-temperature heat source heater 15 through the accumulator exhaust regulating valve 14, the power outlet of the photovoltaic power generation system 16 is connected to the power inlet of the energy storage device 17, and the power outlet of the energy storage device 17 is connected to the power inlet of the backup low-temperature electric heater 18.

[0031] The water inlet of the standby low-temperature electric heater 18 is connected to the heating pipe through a standby water inlet pipe, and a standby heating network water inlet valve 19 is arranged on the standby water inlet pipe. The water outlet of the standby low-temperature electric heater 18 is connected to the water inlet of the standby high-temperature heat source heater 15, and the water outlet of the standby high-temperature heat source heater 15 is connected to the heating pipe through a standby water outlet pipe, and a standby heating network water outlet valve 21 is arranged on the standby water outlet pipe. A heating network water valve 20 is also arranged on the heating pipe between the standby water inlet pipe and the standby water outlet pipe.

[0032] Under normal operating conditions, the standby heating network water inlet valve 19 and the standby heating network water outlet valve 21 are closed, the heating network water valve 20 is opened, the water in the heating pipe does not flow through the heating network standby heat source subsystem 24, and is heated by the ACP nuclear power heating unit. Under accident shutdown conditions, the standby heating network water inlet valve 19 and the standby heating network water outlet valve 21 are opened, the heating network water valve 20 is closed, the water in the heating pipe flows through the standby low-temperature electric heater 18 and the standby high-temperature heat source heater 15 in turn, and is heated by the heating network standby heat source subsystem 24.

[0033] The photovoltaic power generation system 16 serves as a backup power source for the heating network in the event of an accident shutdown. The photovoltaic power generation system 16, the energy storage device 17 and the numerical control system constitute a comprehensive intelligent energy system, wherein the photovoltaic power generation system 16 uses an N-type heterojunction photovoltaic module, and the energy storage device 17 is a container-type energy storage power station using a lithium iron phosphate battery pack. Under the condition that the energy storage power can be sufficient for emergency use during the regular heating and non-heating seasons, the comprehensive intelligent energy system can also realize the access of surplus power to the grid, participate in electricity market transactions, and improve the profitability of nuclear power plants.

[0034] In the heat network backup heat source subsystem 24, the backup low-temperature electric heater 18 uses the electric energy generated by the integrated intelligent energy system to preheat the low-temperature heat network return water. The heat source of the backup high-temperature heat source heater 15 is the steam heat storage of the steam accumulator 13. The heat network water is further heated and then sent out. The purpose is to use the heat storage of the unit itself and the electric energy storage of the integrated intelligent energy system to ensure the heating needs of northern heat users under severe cold conditions when the unit is shut down due to a fault.

[0035] By arranging a standby low-temperature electric heater 18 to preheat the return water from the heat network, the heated water from the heat network has a smaller heat exchange temperature difference when exchanging heat with steam in the standby high-temperature heat source heater 15, thereby effectively saving energy and reducing consumption.

[0036] Embodiment 2 A method for supplying heat using a standby heat source in a heating network, using a standby heat source heating system in a heating network as described in the first embodiment, comprising the following steps: When the nuclear power unit is in normal heating operation, the middle exhaust steam extraction valve 6 is opened, the accumulator steam charging regulating valve 7 is closed, the steam accumulator 13 is shut down, the unit does not store heat, and the accumulator exhaust regulating valve 14 is closed, the standby low-temperature electric heater 18 and the standby high-temperature heat source heater 15 are shut down, the integrated smart energy system operates normally, and the power generated by the photovoltaic power generation system 16 is stored in the energy storage device 17. The heating network heater water inlet valve 11 and the heating network heater water outlet valve 10 are opened, the standby heating network water valve 12 is closed, and the heating network heater 8 is put into operation and bears the heating load. The standby heating network water inlet valve 19 and the standby heating network water outlet valve 21 are closed, and the heating network water valve 20 is opened to send the heated heating network water out.

[0037] When the nuclear power unit is in normal heating operation and deep peak regulation, the accumulator steam charging regulating valve 7 is opened to charge the excess steam into the steam accumulator 13, and the unit accumulates heat. At the same time, the accumulator exhaust regulating valve 14 is closed, the standby low-temperature electric heater 18 and the standby high-temperature heat source heater 15 are shut down, the integrated smart energy system operates normally, and the power generated by the photovoltaic power generation system 16 is stored in the energy storage device 17. The heating network heater water inlet valve 11 and the heating network heater water outlet valve 10 are opened, the standby heating network water valve 12 is closed, and the heating network heater 8 is put into operation and bears the heating load. The standby heating network water inlet valve 19 and the standby heating network water outlet valve 21 are closed, and the heating network water valve 20 is opened to send the heated heating network water out.

[0038] The flexibility of nuclear power heating units can be improved by adding steam accumulators for storing extracted steam heat during deep peak regulation, and adding backup high-temperature heat source heaters for absorbing exhaust heat from the steam accumulators. At the same time, a backup heat source subsystem for the heating network can be added to ensure safe and stable heating under accident conditions.

[0039] When a shutdown fault occurs during the heating period, the heating network heater water inlet valve 11 and the heating network heater water outlet valve 10 are closed, the standby heating network water valve 12 is opened, and the heating network heater 8 is shut down. Due to the shutdown of the unit, the accumulator charging regulating valve 7 is closed, and the accumulator exhaust regulating valve 14 is opened, the standby heating network water inlet valve 19 and the standby heating network water outlet valve 21 are opened, and the heating network water valve 20 is closed. The integrated smart energy system performs primary heating on the heating network return water of the standby low-temperature electric heater 18, and the steam heat storage is sent to the heating network water supply pipeline 23 after secondary heating of the heating network water by the standby high-temperature heat source heater 15.

[0040] By setting a low-temperature electric heater to preheat the return water of the heating network, the heated heating network water has a smaller heat exchange temperature difference when exchanging heat with steam in the standby high-temperature heat source heater, effectively saving energy and reducing consumption.

[0041] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A heating network standby heat source heating system, characterized in that: It includes CAP nuclear power heating unit and heat network standby heat source subsystem, both of which are connected to the heating pipeline; A steam accumulator is also provided. The steam extraction port of the intermediate pressure cylinder of the steam turbine in the CAP nuclear power heating unit is connected to the air inlet of the steam accumulator through the accumulator steam charging regulating valve, and the steam exhaust port of the steam accumulator is connected to the steam inlet of the standby high-temperature heat source heater in the standby heat source subsystem of the heating network through the accumulator steam exhaust regulating valve.

2. A heating network backup heat source heating system as claimed in claim 1, characterized in that: The CAP nuclear power heating unit includes a reactor, a steam generator, a steam turbine and a heat network heater, wherein the reactor is connected to the steam generator, the steam outlet of the steam generator is connected to the steam inlet of the intermediate pressure cylinder of the steam turbine, the exhaust port of the intermediate pressure cylinder is connected to the steam inlet of the low pressure cylinder, the steam turbine is also connected to the generator, and the intermediate pressure cylinder, the low pressure cylinder and the generator are coaxially arranged.

3. A heating network backup heat source heating system as claimed in claim 2, characterized in that: The steam extraction port of the intermediate pressure cylinder is connected to the steam inlet of the heat network heater through the intermediate exhaust steam extraction valve, and the water inlet and water outlet of the heat network heater are both connected to the heating pipeline.

4. A heating network backup heat source heating system as claimed in claim 3, characterized in that: The water inlet of the heating network heater is connected to the heating pipe through an inlet pipe, and a heating network heater inlet valve is arranged on the inlet pipe. The water outlet of the heating network heater is connected to the heating pipe through an outlet pipe, and a heating network heater outlet valve is arranged on the outlet pipe.

5. A heating network backup heat source heating system as claimed in claim 4, characterized in that: A standby heating network water valve is arranged on the heating pipe between the water inlet pipe and the water outlet pipe.

6. A heating network backup heat source heating system as claimed in claim 1, characterized in that: The backup heat source subsystem of the heating network includes a backup high-temperature heat source heater, a backup low-temperature electric heater, a photovoltaic power generation system and an energy storage device, wherein the exhaust port of the steam accumulator is connected to the heat source steam inlet of the backup high-temperature heat source heater through the accumulator exhaust regulating valve, the power outlet of the photovoltaic power generation system is connected to the power inlet of the energy storage device, and the power outlet of the energy storage device is connected to the power inlet of the backup low-temperature electric heater.

7. A heating network backup heat source heating system as claimed in claim 6, characterized in that: The water inlet of the standby low-temperature electric heater is connected to the heating pipe through a standby water inlet pipe, and a standby heating network water inlet valve is arranged on the standby water inlet pipe. The water outlet of the standby low-temperature electric heater is connected to the water inlet of the standby high-temperature heat source heater, and the water outlet of the standby high-temperature heat source heater is connected to the heating pipe through a standby water outlet pipe, and a standby heating network water outlet valve is arranged on the standby water outlet pipe.

8. A heating network backup heat source heating system as claimed in claim 7, characterized in that: A heat network water valve is also provided on the heating pipeline between the spare water inlet pipeline and the spare water outlet pipeline.

9. A heating network backup heat source heating system as claimed in claim 6, characterized in that: The photovoltaic power generation system adopts N-type heterojunction photovoltaic modules, and the energy storage device is a container-type energy storage power station using lithium iron phosphate battery packs.

10. A method for supplying heat using a standby heat source in a heating network, using a standby heat source heating device for a heating network as claimed in any one of claims 1 to 9, characterized in that: The following steps are involved: When the nuclear power unit is operating normally for heating and deep peak regulation, the accumulator steam charging regulating valve is opened to charge the excess steam into the steam accumulator, and the unit stores heat. At the same time, the accumulator exhaust regulating valve is closed, the standby low-temperature electric heater and the standby high-temperature heat source heater are shut down, and the integrated smart energy system operates normally. The electricity generated by the photovoltaic power generation system is stored in the energy storage device, the heating network heater water inlet valve and the heating network heater water outlet valve are opened, the standby heating network water valve is closed, the heating network heater is put into operation and assumes the heating load, the standby heating network water inlet valve and the standby heating network water outlet valve are closed, and the heating network water valve is opened to send the heated heating network water out; When a shutdown failure occurs during the heating period, the water inlet valve and the water outlet valve of the heating network heater are closed, the standby heating network water valve is opened, and the heating network heater is shut down; due to the shutdown of the unit, the steam charging regulating valve of the heat accumulator is closed, and at the same time the steam exhaust regulating valve of the heat accumulator is opened, the standby heating network water inlet valve and the standby heating network water outlet valve are opened, and the heating network water valve is closed. The integrated smart energy system performs primary heating on the heating network return water of the standby low-temperature electric heater, and the steam heat storage is secondary heated up by the standby high-temperature heat source heater before being sent to the heating network water supply pipeline.

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