Thermal power peak regulation system based on solid oxide fuel cell and working method
Technical Field
The invention belongs to the field of thermal power generation, and particularly relates to a thermal power peak regulation system based on a solid oxide fuel cell and a working method.
Background
With the rapid development of economy and the improvement of the living standard of people, the electricity utilization structure is greatly changed, and the valley-peak difference of the power grid is increased day by day; in addition, the generated energy of new energy such as wind power, photovoltaic and the like is rapidly increased, the requirements on the peak regulation capacity and the operation flexibility of the thermal power generating unit are higher and higher, and more thermal power generating units with high parameters and large capacity are responsible for peak regulation of a power grid. But limited by the lowest stable combustion load and the like, the participating peak shaving depth of the large-scale unit is limited. How to make the thermal power generating unit have better peak regulation depth to adapt to the requirement of new energy rapid development under the premise of ensuring the peak regulation safety of the unit is a problem to be solved urgently in the power industry.
In recent years, in order to improve the peak regulation depth of a unit, not only is the unit system modified, such as low-pressure cylinder zero-output modification which is widely applied recently, but also an auxiliary system is added to the original system to improve the peak regulation depth, such as a lava heat storage system and a flywheel energy storage system are added.
Disclosure of Invention
The invention aims to overcome the defects and provides a thermal power peak regulating system based on a solid oxide fuel cell and a working method thereof.
In order to achieve the purpose, the thermal power peak regulation system based on the solid oxide fuel cell comprises the solid oxide fuel cell, wherein the cathode of the solid oxide fuel cell is connected with a hydrogen tank and a reheat steam outlet pipe, the anode of the solid oxide fuel cell is connected with an oxygen tank, the solid oxide fuel cell is connected with an inverter, and the inverter is connected with a generator.
The cathode and the anode of the solid oxide fuel cell are both connected with the catalytic combustor.
A cathode heat exchanger is arranged on a pipeline between the hydrogen tank and the cathode of the solid oxide fuel cell, and an anode heat exchanger is arranged on a pipeline between the oxygen tank and the anode of the solid oxide fuel cell.
High-temperature steam discharged from the catalytic combustion chamber is used as a heat source and sent into the cathode heat exchanger and the anode heat exchanger.
And heat sources after heat exchange in the cathode heat exchanger and the anode heat exchanger are sent into the low-pressure cylinder through pipelines.
The reheat steam is led out from the reheat steam side of the boiler.
A working method of a thermal power peak regulation system based on a solid oxide fuel cell comprises the following steps:
when the unit is in a peak power consumption state, hydrogen stored in the hydrogen tank is sent to the cathode of the solid oxide fuel cell, oxygen stored in the oxygen tank is sent to the anode of the solid oxide fuel cell, the solid oxide fuel cell performs a power generation reaction, and the generated electricity is supplemented to the generator for power generation through the inverter;
when the unit is in the electricity consumption valley, the reheated steam is sent to the cathode of the solid oxide fuel cell to carry out reverse reaction, electricity is taken from the generator through the inverter to be supplied to the solid oxide fuel cell as electricity for the reheated steam electrolysis, hydrogen generated by the cathode of the electrolyzed solid oxide fuel cell is stored in the hydrogen tank, and oxygen generated by the anode is stored in the oxygen tank.
And high-temperature steam discharged from the catalytic combustion chamber is used as a heat source for preheating hydrogen and oxygen and is respectively sent into the cathode heat exchanger and the anode heat exchanger.
And heat sources after heat exchange in the cathode heat exchanger and the anode heat exchanger are converged into a low-pressure cylinder of the steam turbine to do work.
Compared with the prior art, the invention improves the frequency modulation capability of the system by adding the solid oxide fuel cell system in the unit steam system: according to the invention, the power generation is supplemented through the oxidation reaction of hydrogen and oxygen at the power consumption peak, and the steam generated after the incompletely-reacted part is combusted is supplemented to the system, so that the work capacity of the system is improved, and the flexibility of a unit is improved; according to the invention, energy is stored by electrolyzing steam in the steam system of the unit during the power consumption valley, so that the power supply amount of the unit is reduced, and the peak regulation depth is increased; the invention ensures that the positive reaction efficiency and the reverse reaction efficiency of the solid oxide fuel are high, and the efficiency of the whole system can be ensured; the solid oxide fuel has the characteristic of low pollution, and no more polluting gas is generated in the whole process.
Drawings
FIG. 1 is a block diagram of the system of the present invention;
the fuel cell comprises a solid oxide fuel cell 1, a cathode 2, a hydrogen tank 3, a hydrogen tank 4, an anode 5, an inverter 6, a generator 7, an oxygen tank 8, a catalytic combustion chamber 9, a cathode heat exchanger 10, an anode heat exchanger 11, a low-pressure cylinder 12 and a boiler.
Detailed Description
The invention is further described below with reference to the accompanying drawings.
Referring to fig. 1, the thermal power peak-shaving system based on the solid oxide fuel cell comprises a solid oxide fuel cell 1, wherein a cathode 2 of the solid oxide fuel cell 1 is connected with a hydrogen tank 3 and a reheat steam outlet pipe, reheat steam is led out from the reheat steam side of a boiler 12 (the temperature exceeds 600 ℃), an anode 4 of the solid oxide fuel cell 1 is connected with an oxygen tank 7, the solid oxide fuel cell 1 is connected with an inverter 5, and the inverter 5 is connected with a generator 6. The cathode 2 and the anode 4 of the solid oxide fuel cell 1 are both connected to a catalytic combustor 8. A cathode heat exchanger 9 is arranged on a pipeline between the hydrogen tank 3 and the cathode 2 of the solid oxide fuel cell 1, and an anode heat exchanger 10 is arranged on a pipeline between the oxygen tank 7 and the anode 4 of the solid oxide fuel cell 1. The high-temperature steam discharged from the catalytic combustor 8 is used as a heat source and sent to the cathode heat exchanger 9 and the anode heat exchanger 10. And heat sources after heat exchange in the cathode heat exchanger 9 and the anode heat exchanger 10 are sent into the low-pressure cylinder 11 through pipelines, so that the generating capacity of the steam turbine is improved.
A working method of a thermal power peak regulation system based on a solid oxide fuel cell comprises the following steps:
when the unit is in a peak power utilization state, hydrogen stored in the hydrogen tank 3 is sent to the cathode 2 of the solid oxide fuel cell 1, oxygen stored in the oxygen tank 7 is sent to the anode 4 of the solid oxide fuel cell 1, the solid oxide fuel cell 1 carries out power generation reaction, and the generated electricity supplements the generator 6 to generate electricity through the inverter 5; the incomplete combustion products enter the catalytic combustion chamber 8 when the solid oxide fuel cell 1 performs power generation reaction, and high-temperature steam discharged from the catalytic combustion chamber 8 is used as heat sources for preheating hydrogen and oxygen and is respectively sent into the cathode heat exchanger 9 and the anode heat exchanger 10. The heat source after heat exchange in the cathode heat exchanger 9 and the anode heat exchanger 10 is converged into a low-pressure cylinder 11 of the steam turbine to do work.
When the unit is in the electricity consumption valley, the reheated steam is sent to the cathode 2 of the solid oxide fuel cell 1 to perform reverse reaction, electricity is taken from the generator 6 through the inverter 5 to be supplied to the solid oxide fuel cell 1 as electricity for the reheated steam electrolysis, hydrogen generated by the cathode 2 of the solid oxide fuel cell 1 after the electrolysis is stored in the hydrogen tank 2, and oxygen generated by the anode 4 is stored in the oxygen tank 7.