Phase change energy storage recycling device based on surplus electric quantity of nuclear power station and thermoelectric conversion system

Abstract

The invention belongs to the technical field of phase change energy storage heat exchange, and particularly relates to a phase change energy storage recycling device based on surplus electric quantity of a nuclear power station and a thermoelectric conversion system. The contradiction between electric energy supply and demand mismatch is a key problem in the industry. At present, methods such as transformation and capacity expansion of power generation equipment are adopted, consumption is large, and the energy utilization rate is low. Therefore, surplus electric quantity in the low-load period is converted into heat energy to be stored, and then the heat energy is converted into electric energy to be used in the peak-load period. The adopted phase change energy storage material (Al-Si-Fe-Sn) has the advantages of being large in heat conductivity coefficient, high in latent heat density, low in material cost, efficient, energy-saving, environment-friendly and the like, heat energy at the temperatures of about 200 DEG C, about 500 DEG C, about 600 DEG C or above and the like can be continuously absorbed according to multiple phase change points of the phase change material, and the high, medium and low heat energy is integrally stored for efficient utilization; therefore, the problem that the energy utilization rate is low due to mismatching and non-uniformity of energy supply on time or places is solved, and the heat utilization rate of the whole system is improved to the maximum extent.

Description

Technical Field

[0001] The invention relates to a phase change energy storage recovery and utilization device and a thermoelectric conversion system based on excess electricity of a nuclear power plant, belonging to the technical field of phase change energy storage and heat exchange. Background Art

[0003] With the development of industrialization and the improvement of people's living standards, the requirements for the balance of power supply and demand are getting higher and higher, the stability of the power grid is increasingly affected, and the power utilization rate is also decreasing. In order to cope with the increasing peak-to-valley difference in load, traditional means have continuously expanded investment by investing a lot of manpower, material and financial resources, such as the transformation and expansion of power generation equipment, etc. However, these methods are not only huge in consumption, but also have low energy utilization. To this end, a phase change energy storage recovery and utilization device and a thermoelectric conversion system based on the excess power of nuclear power plants are proposed, which can fully store the power during low load periods for use during peak load periods, and can be used to solve the contradiction between power supply and demand mismatch. Summary of the invention

[0004] 1. The key to solve

[0005] The purpose of the present invention is to address the problem of a large amount of excess electricity being wasted due to the increase in the peak-to-valley difference in the power system load, and to propose a phase change energy storage recovery and utilization device and a thermoelectric conversion system based on the excess electricity of a nuclear power plant. The system can store the electricity generated at low loads, and release the electricity at high loads to relieve the pressure on the power grid and ensure the smooth operation of the power grid. This solves the problem of low energy utilization due to energy supply mismatch and unevenness in time or place, and maximizes the thermal utilization of the overall system.

[0006] 2. Technical solution

[0007] The technical solution of the present invention is as follows: A phase change energy storage recycling device and thermoelectric conversion system based on excess electricity in a nuclear power plant includes a phase change energy storage unit, a heating unit, a heat exchange unit and an energy generation unit. The phase change energy storage unit includes a phase change energy storage material and a box body for storing thermal energy; the heating unit includes a resistance wire, a resistance wire protection channel and a stainless steel pipe for heating the phase change energy storage material in the phase change energy storage unit to a set temperature; the heat exchange unit includes a water pump, a flow meter, a flow regulating valve, a water pipe channel, a water outlet valve and a steam drum for converting the thermal energy stored in the phase change energy storage material into the form of water vapor; the energy generation unit includes a reactor, a voltage regulator, a steam generator, a high-pressure cylinder, a steam turbine, a generator and a power grid for transmitting excess electricity to the heating unit. During the off-peak period of the power grid, the excess electricity transmitted by the generator heats the resistance wire in the heating unit to complete the conversion of electrical energy to thermal energy; then the thermal conductivity is increased through the stainless steel pipe to conduct the thermal energy to the phase change energy storage unit. The phase change energy storage material in the box melts and absorbs the heat emitted by the resistance wire and stores it. The phase change energy storage material is Al-Si-Fe-Sn, where the range of each element is X Si =12.5%, 1%≤X Fe ≤9%、0.8%≤X Sn ≤56.8%, with multiple phase transition points, and can continuously absorb heat energy with phase transition temperatures of about 200°C, about 500°C, and above about 600°C.

[0008] The high, medium and low heat energy are stored in an integrated manner for efficient use. Then, an insulation layer is set on the outside of the box to prevent heat loss. When the power grid reaches its peak, the water pump in the heat exchange unit passes water through the flow regulating valve into the water pipeline to solidify the phase change energy storage material and take away the heat energy in the form of water vapor. Finally, it enters the steam drum to complete the gas-liquid separation, and the water vapor enters the high-pressure cylinder and is incorporated into the overall process so that it can be reused to generate electricity through the generator. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is the principle flow chart of the thermoelectric conversion system;

[0010] Figure 2 This is a front view schematic diagram of the phase change energy storage equipment;

[0011] Figure 3 It is a cross-sectional schematic diagram of phase change energy storage equipment;

[0012] The markings of the components in the accompanying drawings are as follows:

[0013] 1: Reactor;

[0014] 2: Voltage stabilizer;

[0015] 3: Steam generator;

[0016] 4: High pressure cylinder;

[0017] 5: Steam turbine;

[0018] 6: Generator;

[0019] 7: Power grid;

[0020] 8: Steam drum;

[0021] 9: Water outlet valve;

[0022] 10: Flow meter;

[0023] 11: Flow control valve;

[0024] 12: Water pump;

[0025] 13: Temperature sensor;

[0026] 14: Box;

[0027] 15: Phase change energy storage material filling pipeline;

[0028] 16: Water pipeline;

[0029] 17: Insulation material;

[0030] 18: Resistance wire protection channel;

[0031] 19: resistance wire;

[0032] 20: Phase change energy storage materials;

[0033] 21: Stainless steel pipe;

[0034] 22: Fixing parts. DETAILED DESCRIPTION

[0035] The present invention is described in detail below in conjunction with the accompanying drawings through specific implementation cases so that the advantages and features of the present invention can be more easily understood by those skilled in the art. It should be noted that the description of these implementation methods is used to help understand the present invention, but does not constitute a limitation of the present invention.

[0036] Examples

[0037] During the off-peak period of the power grid, the excess electricity delivered by the generator heats the resistance wire (19) in the heating unit. After the resistance wire (19) is heated, it is transferred to the stainless steel pipe (21) by heat conduction, so that the phase change energy storage material (20) melts, absorbs heat and stores it, completing the conversion from electrical energy to thermal energy. The phase change energy storage material (20) is Al-Si-Fe-Sn, wherein each element ranges from X Si =12.5%, 1%≤X Fe≤9%、0.8%≤X Sn ≤56.8%, the phase change temperature is around 200℃, around 500℃, and above 600℃, the high, medium and low heat

[0038] It can be stored in an integrated manner for efficient use. A heat preservation layer is wrapped outside the box (14) to prevent heat loss. When the peak period of the power grid comes, the water pump (12) in the heat exchange unit passes water through the flow regulating valve (11) and enters the water pipe (16) to solidify the phase change energy storage material (20) and take away the heat energy in the form of water vapor. Finally, it enters the steam drum (8) to complete gas-liquid separation, and the water vapor enters the high-pressure cylinder (4), so that it can be reused and incorporated into the overall system to generate electricity through the generator (6).

[0039] The above is only an embodiment of the present invention with better effects, and is not intended to limit the scope of the present invention. Any simple deformation or equivalent transformation made by any technician based on the content of the present invention, or directly or indirectly applied in other related technical fields, is included in the scope of the present invention.

Claims

1. A phase change energy storage recovery and utilization device and thermoelectric conversion system based on excess electricity from nuclear power plants, characterized in that It includes a phase change energy storage unit, a heating unit, a heat exchange unit and an energy generation unit. The phase change energy storage unit includes a phase change energy storage material and a box body, which is used to store thermal energy; The heating unit includes a resistance wire, a resistance wire protection channel and a stainless steel tube, which are used to heat the phase change energy storage material in the phase change energy storage unit to a set temperature; The heat exchange unit includes a water pump, a flow meter, a flow regulating valve, a water pipe channel, a water outlet valve and a steam drum, which are used to convert the heat energy stored in the phase change energy storage material into water vapor, and then merge it into the high-pressure cylinder and integrate it with the overall circuit; The energy generation unit includes a reactor, a pressurizer, a steam generator, a high-pressure cylinder, a steam turbine, a generator and a power grid, which are used to transmit excess electricity to the heating unit.

2. A phase change energy storage recovery and utilization device and thermoelectric conversion system based on excess electricity of a nuclear power plant according to claim 1, characterized in that: The phase change energy storage material is Al-Si-Fe-Sn, wherein the range of each element is X Si =12.5%,1%≤X Fe ≤9%、0.8%≤X Sn ≤56.8%, with multiple phase transition points, it can continuously absorb heat energy with phase transition temperatures of around 200°C, around 500°C, and above around 600°C, and store high, medium and low heat energy in an integrated manner for efficient use.

3. A phase change energy storage recovery and utilization device and thermoelectric conversion system based on excess electricity of a nuclear power plant according to claim 1, characterized in that: The outer surface of the box is wrapped with heat-insulating material to prevent heat loss. The top of the box is provided with a filling port for phase-change energy storage material and is closed by a plug.

4. A phase change energy storage recovery and utilization device and thermoelectric conversion system based on excess electricity of a nuclear power plant according to claim 1, characterized in that: The resistance wire is provided with a temperature sensor for measuring the temperature of the resistance wire; the resistance wire protection pipe is made of ceramic material. The outer side of the resistance wire protection pipe is a stainless steel pipe to accelerate its heat conduction rate. The outer side of the stainless steel pipe is provided with a fixing piece for connecting the box body and the stainless steel pipe.

5. A phase change energy storage recovery and utilization device and thermoelectric conversion system based on excess electricity of a nuclear power plant according to claim 1, characterized in that: The steam drum is connected to the high-pressure cylinder and the outlet valve respectively for water vapor separation; the flow regulating valve is connected to the flow meter and the water pump for regulating the water flow, and the flow meter is used to record the water flow.

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