Thermal power plant thermoelectric decoupling system based on solid electric heat storage device

Abstract

The invention discloses a thermal power plant thermoelectric decoupling system based on a solid electric heat storage device, relates to solid electric heat storage equipment and a power plant decoupling system, and aims at achieving the flexibility of a thermal power generating unit in power generation work and achieving the purpose of mutual conversion of heat and electricity. The system comprises a boiler, a steam turbine, a valve group and a group of solid electric heat storage devices, the outlet end of the steam turbine water return pipeline is communicated with the inlet end of the boiler, the steam outlet end of the boiler is communicated with the steam inlet end of the steam turbine, the valve set is installed on the steam turbine water return pipeline, and the solid electric heat storage device and the valve set are installed on the steam turbine water return pipeline in parallel. The invention is applied to the field of thermal power generating unit power generation.

Description

Technical Field

[0001] The present invention relates to a solid-state electric heat storage device and a power plant decoupling system, and in particular to a thermal power plant thermoelectric decoupling system based on a solid electric heat storage device. The present invention is applied to the field of power generation of thermal power units. Background Art

[0002] Cogeneration refers to the simultaneous generation of heat and power (CHP) by a thermal power unit using steam extraction or exhaust from the turbine to provide heat to users. Because there is no cooling loss, efficiency can reach around 80%. This operation typically prioritizes heat-to-electricity, closely linking user heat use with power generation. However, this lacks flexibility. Therefore, a solution is needed to achieve flexibility in the generation of thermal power units, enabling the mutual conversion of heat and electricity. Summary of the Invention

[0003] The purpose of the present invention is to achieve the flexibility of thermal power units in power generation, to achieve the purpose of mutual conversion of heat and electricity, and to provide a thermal power plant thermoelectric decoupling system based on a solid electric heat storage device.

[0004] The technical solution adopted by the present invention to solve the above problems is:

[0005] A thermal power plant thermoelectric decoupling system based on a solid electric heat storage device, comprising a boiler, a steam turbine, a valve group and a group of solid electric heat storage devices;

[0006] The outlet end of the steam turbine water return pipeline is connected with the inlet end of the boiler, the steam outlet end of the boiler is connected with the steam inlet end of the steam turbine, the valve group is installed on the steam turbine water return pipeline, and a group of solid electric heat storage devices and the valve group are installed in parallel on the steam turbine water return pipeline.

[0007] Further, the valve group includes a first valve and a second valve;

[0008] The first valve and the second valve are sequentially installed in series on the water return pipe of the steam turbine.

[0009] Furthermore, a set of solid electric heat storage devices includes two solid electric heat storage devices,

[0010] The first valve is installed in parallel with a solid electric heat storage device on the water return pipeline of the steam turbine, and the second valve is installed in parallel with a solid electric heat storage device on the water return pipeline of the steam turbine.

[0011] Furthermore, it also includes two heat exchangers, a solid electric heat storage device is arranged in parallel with the first valve through a heat exchanger on the turbine water return pipeline, and another solid electric heat storage device is arranged in parallel with the second valve through a heat exchanger on the turbine water return pipeline.

[0012] Furthermore, the water inlet and outlet of the heat exchanger are connected to the water return pipeline of the turbine, and the air inlet and outlet of the heat exchanger are connected to the air duct of the solid electric heat storage device.

[0013] Furthermore, it also includes two 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.

[0014] Furthermore, it also includes two fans and a water pump, which is installed on the water return pipeline of the steam turbine.

[0015] Beneficial effects of the present invention:

[0016] 1. From the perspective of the Rankine cycle of the thermal power system, a system solution suitable for the flexibility transformation of thermal power plants is proposed. The boiler return water is unidirectionally coupled with a solid electric thermal storage device. Through the use of an external heat storage heat source, multi-quality cascade utilization of energy at different times and spaces within the thermal power plant is achieved. This improves system efficiency and flexibility without changing the boiler capacity, thus achieving thermoelectric decoupling.

[0017] 2. The technical solution of the present invention is to couple the solid-state heat storage device with the water supply system of the thermal power plant to realize the flexible transformation of the thermal power unit. During the valley and flat periods of electricity consumption, the unit does not heat the feed water, and the excess electricity is input into the solid electric heat storage device to achieve "valley filling"; during the peak period of electricity consumption, the back-pressure steam turbine runs at full load, and the heat in the heat storage body is input into the boiler feed water through the fan, thereby improving the feed water parameters and thus improving the quality of boiler steam production, so as to make the steam turbine have better output. The temperature range of the hot air output by the solid storage equipment is 100-900℃, which meets the boiler feed water requirements of most units.

[0018] 3. The present invention realizes hierarchical and cascaded utilization of energy at different times and spaces by externally placing a solid electric heat storage device on the water feed of the thermal power station, thereby increasing the absorption methods of new energy and off-peak power generation to achieve "valley filling". With minimal modification to the original system, the operational flexibility of the thermal power plant is improved. For a certain power plant, the maximum operating output can be increased by 10%. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the overall structure of this application. DETAILED DESCRIPTION

[0020] Specific implementation method 1: Combination Figure 1 This embodiment describes a thermal power plant thermoelectric decoupling system based on a solid electric thermal storage device, which includes a boiler 1, a steam turbine 2, a valve group, and a group of solid electric thermal storage devices 5;

[0021] The outlet end of the water return pipeline of turbine 2 is connected to the inlet end of boiler 1, and the steam outlet end of boiler 1 is connected to the steam inlet end of turbine 2. The valve group is installed on the water return pipeline of turbine 2, and a group of solid electric heat storage devices 5 are installed in parallel with the valve group on the water return pipeline of turbine 2.

[0022] Specific implementation method 2: Combination Figure 1 This embodiment describes a thermoelectric decoupling system for a thermal power plant based on a solid electric thermal storage device, wherein the valve group includes a first valve 3 and a second valve 4;

[0023] The first valve 3 and the second valve 4 are sequentially installed in series on the water return pipe of the steam turbine 2. Other methods are the same as those in the first embodiment.

[0024] Specific implementation method three: Combination Figure 1 This embodiment describes a thermoelectric decoupling system for a thermal power plant based on a solid electric heat storage device. A set of solid electric heat storage devices 5 includes two solid electric heat storage devices 5.

[0025] The first valve 3 is installed in parallel with a solid electric heat storage device 5 on the water return pipe of the steam turbine 2, and the second valve 4 is installed in parallel with a solid electric heat storage device 5 on the water return pipe of the steam turbine 2. Other methods are the same as those in the second embodiment.

[0026] Specific implementation method four: Combination Figure 1 This embodiment describes a thermal power plant thermoelectric decoupling system based on a solid electric heat storage device. The system also includes two heat exchangers: one solid electric heat storage device 5 is connected in parallel with a first valve 3 via a heat exchanger on the water return line of a steam turbine 2; the other solid electric heat storage device 5 is connected in parallel with a second valve 4 via a heat exchanger on the water return line of a steam turbine 2. The remaining methods are the same as those in the first embodiment.

[0027] Specific implementation method five: Combination Figure 1 This embodiment describes a thermal power plant decoupling system based on a solid electric thermal storage device. The water inlet and outlet of the heat exchanger are connected to the water return line of steam turbine 2, while the air inlet and outlet of the heat exchanger are connected to the air duct of solid electric thermal storage device 5. Other methods are the same as those in the first embodiment.

[0028] Specific implementation method six: combination Figure 1 This embodiment describes a thermal power plant thermoelectric decoupling system based on a solid electric thermal storage device. The system also includes two fans, each of which is installed on an air duct of the solid electric thermal storage device 5 near the solid electric thermal storage device 5. Other methods are the same as those in the first embodiment.

[0029] Specific implementation method seven: combination Figure 1This embodiment describes a thermal power plant thermoelectric decoupling system based on a solid electric thermal storage device, which also includes a water pump installed on the water return line of the steam turbine 2. Other methods are the same as those of the sixth embodiment.

[0030] When the system operates in the valley and flat sections of electricity consumption, the first valve 3 and the second valve 4 are opened, short-circuiting the heat exchanger, and the solid electric heat storage device 5 is turned on in the heat storage mode without external output. At this time, the electricity consumption in the valley section can be increased, 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 5 itself can also leave space for the power grid to accept new energy access at any time.

[0031] During peak electricity consumption, the pipeline valves are switched, the first valve 3 and the second valve 4 are closed, and the solid electric heat storage device 5 side circulation is opened. The solid electric heat storage device uses a centrifugal fan to transfer the heat stored in the valley section of the heat storage body to the boiler feed water through the heat exchanger to increase the feed water temperature. The water temperature at the heat exchanger outlet is monitored during operation, and the frequency of the variable frequency fan is adjusted with the help of 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 cascade utilization of energy across time and space.

[0032] The above-mentioned specific implementation can be partially adjusted in different ways by those skilled in the art without departing from the principles and purpose of the present invention. The scope of protection of the present invention shall be based on the claims and shall not be limited by the above-mentioned specific implementation. All implementation schemes within its scope shall be subject to the constraints of the present invention.

Claims

1. A thermal power plant thermal-electric decoupling system based on a solid electric heat storage device, characterized in that: It comprises a boiler (1), a steam turbine (2), a valve group and a group of solid electric heat storage devices (5); The outlet end of the water return pipeline of the steam turbine (2) is connected to the inlet end of the boiler (1), the steam outlet end of the boiler (1) is connected to the steam inlet end of the steam turbine (2), a valve group is installed on the water return pipeline of the steam turbine (2), and a group of solid electric heat storage devices (5) are installed in parallel with the valve group on the water return pipeline of the steam turbine (2).

2. According to claim 1, a thermal power plant thermal-electric decoupling system based on a solid electric heat storage device is characterized in that: The valve group comprises a first valve (3) and a second valve (4); The first valve (3) and the second valve (4) are sequentially installed in series on the water return pipeline of the steam turbine (2).

3. According to claim 2, a thermal power plant thermal-electric decoupling system based on a solid electric heat storage device is characterized in that: A set of solid electric heat storage devices (5) comprises two solid electric heat storage devices (5), The first valve (3) is installed in parallel with a solid electric heat storage device (5) on the water return pipeline of the steam turbine (2), and the second valve (4) is installed in parallel with a solid electric heat storage device (5) on the water return pipeline of the steam turbine (2).

4. According to claim 3, a thermal power plant thermal-electric decoupling system based on a solid electric heat storage device is characterized in that: It also includes two heat exchangers, one solid electric heat storage device (5) is connected in parallel with a first valve (3) via a heat exchanger and arranged on the water return pipeline of the steam turbine (2), and the other solid electric heat storage device (5) is connected in parallel with a second valve (4) via a heat exchanger and arranged on the water return pipeline of the steam turbine (2).

5. According to claim 4, a thermal power plant thermal-electric decoupling system based on a solid electric heat storage device is characterized in that: The water inlet and outlet of the heat exchanger are in communication with the water return pipeline of the steam turbine (2), and the air inlet and outlet of the heat exchanger are in communication with the air duct of the solid electric heat storage device (5).

6. A thermal power plant thermal-electric decoupling system based on a solid electric heat storage device according to claim 3, 4 or 5, characterized in that: It also comprises two fans, each of which is installed on the air duct of the solid electric heat storage device (5) close to the solid electric heat storage device (5).

7. According to claim 4, a thermal power plant thermal-electric decoupling system based on a solid electric heat storage device is characterized in that: It also includes a water pump which is installed on the water return pipeline of the steam turbine (2).

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