Peak shaving system for coupling external solid heat storage device and thermal power plant
By introducing a peak shaving system coupled with the thermal power plant in the thermal power plant, the problem of insufficient peak shaving flexibility of thermal power units is solved, the cascade utilization of thermal energy and new energy consumption are achieved, and the power generation capacity and system efficiency are improved.
Patent Information
- Application Number
- CN202510092872.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-21
- Publication Date
- 2025-04-25
AI Technical Summary
The thermal power unit lacks flexibility in peak-shaving operation, which limits the power plant output during peak use and makes it difficult to effectively absorb renewable energy.
The peak regulating system is adopted that is coupled to the thermal power plant by an external solid heat storage device, and is connected to the main water supply pipeline of the turbine through a gas-water heat exchanger, and is coupled to the heat recovery system by a solid heat storage device, so as to realize the cascade utilization of heat energy and flexible peak regulating.
It improves the peak shaving flexibility of thermal power units, increases the new energy consumption pathway, realizes the cascade utilization of time and space of heat, and improves power generation capacity and system efficiency.
Smart Images
Figure CN119878332A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a solid-state electric heat storage device and a power plant coupling system, and in particular to a peak-shaving system of an external solid heat storage device coupled with a thermal power plant. The present invention is applied to the field of power generation of thermal power units. Background Art
[0002] In order to improve the cycle efficiency, thermal power units use heat extraction steam heating to increase the boiler feed water temperature and reduce the cold source loss in the condenser. The first and second laws of thermodynamics provide reasonable explanations, but heat extraction steam increases the steam consumption rate of the steam system, which leads to a reduction in power generation under the same boiler steam production, limits the power plant output during peak power consumption, and makes the flexibility of system operating condition adjustment worse. Under the background of "dual carbon", thermal power, as the ballast stone in the energy supply field, must undertake more frequent peak-shaving tasks for the large-scale grid connection of new energy, so the problem of improving the flexibility of thermal power units themselves to absorb renewable energy needs to be solved. Summary of the invention
[0003] The purpose of the present invention is to improve the peak-shaving flexibility of thermal power units themselves to solve the problem of renewable energy consumption, and further provide a peak-shaving system of an external solid heat storage device coupled with a thermal power plant.
[0004] The technical solution adopted by the present invention to solve the above problems is:
[0005] A peak load regulation system in which an external solid heat storage device is coupled with a thermal power plant, comprising a boiler, a steam turbine, a valve group, a three-way valve group and a group of solid electric heat storage devices;
[0006] The outlet of the steam turbine main feed water pipeline is connected to the inlet of the boiler, the steam outlet of the boiler is connected to the steam inlet of the steam turbine, the steam outlet of the steam turbine heat recovery extraction steam is connected to the main feed water pipeline of the steam turbine through a valve group, the three-way valve group is installed on the main feed water pipeline of the steam turbine, and a group of solid electric heat storage devices is connected to the main feed water pipeline of the steam turbine through an air-water heat exchanger.
[0007] The inlet and outlet ends of the water side of the air-water heat exchanger are connected to the main feed water pipeline of the steam turbine, the inlet end of the water side of the air-water heat exchanger is connected to the outlet end of the three-way valve group, and the flow rate of the water side of the air-water heat exchanger is controlled by the three-way valve group, the air inlet and outlet ends of the air side of the air-water heat exchanger are connected to the solid electric heat storage device, and the solid electric heat storage device exchanges heat with the main feed water pipeline of the steam turbine through the air-water heat exchanger.
[0008] Further, the valve group includes a first valve, a second valve, a third valve and a fourth valve;
[0009] The steam outlet of the steam turbine is connected to the heat recovery steam extraction pipe of the steam turbine through the first valve, the second valve, the third valve and the fourth valve respectively.
[0010] Further, the three-way valve group includes a first three-way valve and a second three-way valve;
[0011] An inlet end and an outlet end of the first three-way valve are connected to the main water supply pipeline, and the other outlet end of the first three-way valve is connected to the inlet end of the water side of the air-water heat exchanger, and the heat exchange work of the corresponding heat exchanger is controlled by the first three-way valve. An inlet end and an outlet end of the second three-way valve are connected to the main water supply pipeline, and the other outlet end of the second three-way valve is connected to the inlet end of the water side of the air-water heat exchanger, and the heat exchange work of the corresponding heat exchanger is controlled by the second three-way valve.
[0012] Furthermore, it also includes two variable frequency fans, each of which is installed on the air duct of the solid electric heat storage device close to the solid electric heat storage device.
[0013] Furthermore, it also includes a deaerator, which is installed in the high-pressure and low-pressure water supply pipelines to perform thermal deoxidation.
[0014] Beneficial effects of the present invention:
[0015] 1. The present invention starts from the perspective of the Rankine cycle and the heat recovery cycle of the thermal power system, couples the heat recovery cycle with the solid electric heat storage device in single phase, and realizes the cascade utilization of heat energy at different times in the thermal power plant by introducing an external heat storage heat source, thereby improving the system efficiency and flexibility without changing the boiler capacity.
[0016] 2. The technical solution of the present invention is to couple the solid-state heat storage device with the heat recovery system of the thermal power plant to achieve flexible transformation of the thermal power unit. The heat recovery cycle of the unit in the valley and flat sections operates normally, and the excess electric energy is input into the solid electric heat storage device to achieve "valley filling"; during peak power consumption, the steam extraction and heat recovery steam turbine is no longer operated at full load, the power generation of the power plant is increased, and the heat in the heat storage body is input into the boiler feed water through the fan to meet the rated temperature requirement of the feed water and avoid overheating of the superheater. The temperature range of the hot air output by the solid storage equipment is 100-900℃, which meets the temperature requirement of the boiler feed water.
[0017] 3. The present invention realizes the hierarchical and stepped utilization of heat in time and space by installing an external solid electric heat storage device in the heat recovery cycle of the thermal power station, increases the consumption of new energy and valley-time power generation of the thermal power plant to achieve "valley filling", and improves the operating flexibility of the unit under the condition of minimal modification of the original power plant. The maximum power generation capacity of a 300MW power plant can be increased by 10%. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 This is a schematic diagram of the overall structure of this application. DETAILED DESCRIPTION
[0019] Specific implementation method 1: Combination Figure 1 The present embodiment is described as follows: a peak load regulation system in which an external solid heat storage device is coupled with a thermal power plant, which comprises a boiler 10, a steam turbine 5, a valve group, a three-way valve group and a group of solid electric heat storage devices 11;
[0020] The outlet end of the main feed water pipeline of the steam turbine 5 is connected with the inlet end of the boiler 10, the steam outlet end of the boiler 10 is connected with the steam inlet end of the steam turbine 5, the steam outlet end of the heat recovery extraction steam of the steam turbine 5 is connected with the main feed water pipeline of the steam turbine 5 through a valve group, the three-way valve group is installed on the main feed water pipeline of the steam turbine 5, a group of solid electric heat storage devices 11 is connected with the main feed water pipeline of the steam turbine 5 through an air-water heat exchanger, the inlet end and the outlet end of the water side of the air-water heat exchanger are connected with the main feed water pipeline of the steam turbine 5, the inlet end of the water side of the air-water heat exchanger is connected with the outlet end of the three-way valve group, and the flow rate on the water side of the air-water heat exchanger is controlled by the three-way valve group, the air inlet end and the air outlet end of the air side of the air-water heat exchanger are connected with the solid electric heat storage device 11, and the solid electric heat storage device 11 exchanges heat with the main feed water pipeline of the steam turbine 5 through the air-water heat exchanger.
[0021] The outlet end of the steam turbine heat recovery extraction pipe is connected to the shell side of the high-pressure and low-pressure heaters through a valve group, and the opening of the valve group is adjusted to adjust the heat recovery extraction flow rate; the exhaust steam outlet end of the steam turbine is connected to the inlet end of the air cooler.
[0022] Specific implementation method 2: Combination Figure 1 This embodiment is described. In this embodiment, a peak load regulation system of an external solid heat storage device coupled with a thermal power plant is described. The valve group includes a first valve 3, a second valve 4, a third valve 6 and a fourth valve 7;
[0023] The steam outlet of the heat recovery steam extraction hole of the steam turbine 5 is connected to the main feed water pipeline of the steam turbine 5 through the first valve 3, the second valve 4, the third valve 6 and the fourth valve 7. Other methods are the same as those of the first embodiment.
[0024] Specific implementation method three: Combination Figure 1 This embodiment is described. In this embodiment, a peak load regulation system of an external solid heat storage device coupled with a thermal power plant is described. The three-way valve group includes a first three-way valve 1 and a second three-way valve 8;
[0025] The inlet and outlet of the first three-way valve 1 are connected to the main feedwater pipeline of the steam turbine 5, and the other outlet of the first three-way valve 1 is connected to the steam inlet end of the steam pipe of the air-water heat exchanger, and the heat exchange of the corresponding heat exchanger is controlled by the first three-way valve 1. The inlet and outlet of the second three-way valve 8 are connected to the main feedwater pipeline of the steam turbine 5, and the other outlet of the second three-way valve 8 is connected to the steam inlet end of the steam pipe of the heat exchanger, and the heat exchange of the corresponding heat exchanger is controlled by the second three-way valve 8. Other methods are the same as those in the second specific embodiment.
[0026] Specific implementation method four: Combination Figure 1 This embodiment is described as a peak load regulation system in which an external solid heat storage device is coupled with a thermal power plant, and it also includes two variable frequency fans 9, each variable frequency fan 9 is installed on the air duct of the solid electric heat storage device 11 close to the solid electric heat storage device 11. Other methods are the same as the specific embodiment 1.
[0027] Specific implementation method five: Combination Figure 1 This embodiment is described as a peak load regulation system in which an external solid heat storage device is coupled with a thermal power plant, and it also includes a deaerator 2, and the deaerator 2 is installed on the steam turbine 5. Other methods are the same as those in the first embodiment.
[0028] When the system of the present application is operating in the valley section and the flat section, the first three-way valve 1 and the second three-way valve 8 close the solid storage side circulation, open the channels of the high and low pressure heaters, and the first valve 3, the second valve 4, the third valve 6 and the fourth valve 7 system as a whole adopt a steam extraction heat recovery cycle to ensure system efficiency, and input the excess electric energy of the valley section into the solid electric heat storage device 11 for heat storage, thereby increasing the power consumption of the valley section and avoiding unstable operation and high pollution emissions of the boiler when it is at low load. The existence of the solid electric heat storage device 11 itself can also leave space for the power grid to accept new energy access at any time.
[0029] During peak hours of electricity consumption, the pipeline valves are switched, the first three-way valve 1 and the second three-way valve 8 open the solid storage side circulation, the channels of the high and low pressure heaters are closed, the first valve 3, the second valve 4, the third valve 6 and the fourth valve 7 are closed, the system does not use a heat recovery cycle, the external output power of the steam turbine is increased, the feed water preheating is entrusted to the solid electric heat storage device 11, the heat stored in the valley section of the heat storage body is transported to the boiler feed water by the heat exchanger through the centrifugal fan, the outlet water temperature of the heat exchanger is monitored during operation, and the frequency of the variable frequency fan is adjusted by PID control to achieve feed water temperature control. In response to the heating needs of different equipment, a segmented solid storage heating form is adopted to reduce the entropy loss during operation and realize efficient step-by-step utilization of heat across time and space.
[0030] The above-mentioned specific implementation can be partially adjusted in different ways by those skilled in the art without departing from the principle and purpose of the present invention. The protection scope of the present invention shall be based on the claims and shall not be limited by the above-mentioned specific implementation. Each implementation scheme within its scope shall be subject to the constraints of the present invention.
Claims
1. A peak load regulation system in which an external solid heat storage device is coupled with a thermal power plant, characterized in that: It comprises a boiler (10), a steam turbine (5), a valve group, a three-way valve group and a group of solid electric heat storage devices (11); The outlet end of the main water supply pipeline of the steam turbine (5) is connected to the inlet end of the boiler (10), the steam outlet end of the boiler (10) is connected to the steam inlet end of the steam turbine (5), the steam outlet end of the heat recovery extraction steam of the steam turbine (5) is connected to the main water supply pipeline of the steam turbine (5) through a valve group, the three-way valve group is installed on the main water supply pipeline of the steam turbine (5), a group of solid electric heat storage devices (11) is connected to the main water supply pipeline of the steam turbine (5) through an air-water heat exchanger, The inlet and outlet ends of the water side of the air-water heat exchanger are connected to the main water supply pipeline of the steam turbine (5), the inlet end of the water side of the air-water heat exchanger is connected to the outlet end of the three-way valve group, and the flow rate of the water side of the air-water heat exchanger is controlled by the three-way valve group, the air inlet and outlet ends of the air side of the air-water heat exchanger are connected to the solid electric heat storage device (11), and the solid electric heat storage device (11) exchanges heat with the main water supply pipeline of the steam turbine (5) through the air-water heat exchanger.
2. According to claim 1, a peak load regulation system of an external solid heat storage device coupled with a thermal power plant is characterized in that: The valve group comprises a first valve (3), a second valve (4), a third valve (6) and a fourth valve (7); The steam outlet end of the heat recovery steam extraction hole of the steam turbine (5) is connected to the main feed water pipeline of the steam turbine (5) through the first valve (3), the second valve (4), the third valve (6) and the fourth valve (7).
3. According to claim 1, a peak load regulation system of an external solid heat storage device coupled with a thermal power plant is characterized in that: The three-way valve group comprises a first three-way valve (1) and a second three-way valve (8); An inlet end and an outlet end of a first three-way valve (1) are connected to a main water supply pipeline of a steam turbine (5), and another outlet end of the first three-way valve (1) is communicated with a steam inlet end of a steam pipe of an air-water heat exchanger, and the heat exchange operation of the corresponding heat exchanger is controlled by the first three-way valve (1). An inlet end and an outlet end of a second three-way valve (8) are connected to a main water supply pipeline of a steam turbine (5), and another outlet end of the second three-way valve (8) is communicated with a steam inlet end of a steam pipe of an air-water heat exchanger, and the heat exchange operation of the corresponding heat exchanger is controlled by the second three-way valve (8).
4. According to claim 1, a peak load regulation system of an external solid heat storage device coupled with a thermal power plant is characterized in that: It also includes two variable frequency fans (9), each variable frequency fan (9) being installed on the air duct of the solid electric heat storage device (11) close to the solid electric heat storage device (11).
5. According to claim 1, a peak load regulation system of an external solid heat storage device coupled with a thermal power plant is characterized in that: It also includes a deaerator (2) which is mounted on the steam turbine (5).